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Developing economically sustainable CO2 capture and conversion processes is essential to realize carbon neutrality. This study proposed an integrated process for CO2 capture and conversion-to-methanol (CCTM) and applied machine learning-based optimization to enhance techno-economic-environmental performance. After validating CO2 capture and CO2-to-methanol sections, an advanced CCTM design was developed and compared with conventional one regarding techno-economic-environmental performance across various operating scenarios. The advanced CCTM exhibited significant improvements in energy consumption (14.73–16.30%), production cost (0.81–1.28%), and net CO2 reduction (3.13–3.38%) owing to efficiently reusing waste heat, off-gas, and water resources. The one-at-a-time sensitivity analysis revealed roles of each variable and nonlinear variable-performance tendencies among operating variables in the advanced CCTM process. Subsequently, a well-developed deep neural network (DNN) model precisely formulated the relationship between key variables and performances. The DNN-based optimization provided optimum operating conditions within a minute, resulting in an 8.21 $/tMeOH (∼0.81%) reduction in production cost compared to base case of CCTM. Notably, the total CO2 capture rate of 92.53% at an optimal condition highlighted the significant contribution of advanced CCTM to carbon neutrality. The findings provide a viable reference for the effective and sustainable design and operation of an integrated CCTM process. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
A series of Cu-Mn-Zn/ZrO2 catalysts with different Zn contents were prepared by sol-gel method and characterized by XRD, BET, TPR, N2O-adsorption, XPS, TPD and in-situ DRIFTS. It was found that by increasing a certain amount of Zn, the catalytic activity for CO2 hydrogenation increased. Among all samples, Cu3MnZn0.5Zr0.5 (CMZZ-0.5) possessed the best CO2 conversion (6.5%) and methanol selectivity (73.7%) at 250 °C and 5 MPa. Characterization results showed that Zn entered the Cu1.5Mn1.5O4 spinel structure, forming ZnO x and thus more surface OH groups. This increased the content of Cu0 and Cu α , which improved the activation of H2 and CO2. The pathway of CO2 to methanol was also clarified through in-situ DRIFTS. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
A series of Ce modified CuLDH-Ce x catalysts were synthesized by adding different amounts of Ce to CuMgAl hydrotalcite (CuLDH) catalysts. The physicochemical properties of the catalysts were characterized by X-ray diffraction (XRD), N2 adsorption-desorption (BET), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), etc. The results showed that the addition of Ce changed the hydrotalcite structure of CuLDH catalyst, and an appropriate amount of Ce increased the surface area of the catalyst and improved the dispersion of Cu particles. At the same time, an appropriate amount of Ce was beneficial for increasing the density of strong alkaline sites and the number of oxygen vacancies on the catalyst surface, promoting the adsorption and conversion of CO2. Ce was beneficial for adjusting the Cu+/Cu0 ratio on the catalyst surface, and a higher Cu+/Cu0 ratio was conducive to the formation of methanol. When the Ce/Cu ratio was 0.3, the catalyst exhibited higher activity with 7.5% CO2 conversion, 78.4% methanol selectivity and 362.8 g/(kg·h) spatiotemporal yield at 240 °C under 2.5 MPa with a GHSV=9000 mL/(g·h). It was proved by in-situ DRIFTS that CuLDH-Ce0.3 catalyst followed HCOO* reaction path during CO2 hydrogenation for methanol. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Optimizing the microstructure of copper-based catalysts for CO2 hydrogenation to methanol is an attractive and widely reported strategy, but there are still certain barriers to improving both carbon dioxide conversion rate and methanol product selectivity. Herein, Cu/ZnO/ZrO2/MgO (CZZ1-xMx) catalysts were synthesized by co-precipitation method for CO2 hydrogenation to methanol. Furthermore, the structural features and reaction processes were systematically characterized by XRD, TEM, nitrogen adsorption/desorption, H2-TPR, CO2-TPD and in-situ DRIFT. The results showed that Mg species optimized the microstructure of the catalyst, increased the dispersion of active species and constructed appropriate basic sites. This further enhanced the capture of reactive species and improved the CO2 hydrotreating to methanol reaction performance, which was accompanied by a simultaneous increase in CO2 conversion and methanol yield. It could be convinced that the highest space time yield (STY) of methanol (305.3 gMeOH kgcat −1 h−1) was obtained at 220 °C, WHSV = 18,000 mL gcat −1 h−1 and 3 MPa (XCO2 = 7.28%, SMeOH = 71.8%) for the optimized CZZ0.8M0.2 catalyst, which exhibited twice the CO2 conversion than Cu/ZnO/ZrO2. This work elaborated a scheme for the preparation of efficient methanol catalysts. providing reference for the research of CO2 hydrogenation to methanol process. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Microrod-shaped CuO–ZnO–Al2O3 (CZA) catalysts are synthesized in a single-step hydrothermal method. Several characterization techniques, such as XRD, SEM, BET, XPS, H2-TPR, HR-TEM, and CO2-TPD, are used to investigate the physico-chemical properties of the prepared catalysts. A bench-scale high-pressure fixed-bed flow reactor is used to evaluate the performance of the synthesized catalysts. XRD analysis confirmed the presence of monoclinic CuO and hexagonal ZnO phases in the CZA catalysts. A uniform distribution of interconnected microrod-like morphology is observed in the CZA-4 catalyst. The metal dispersion, metal-support interactions, and surface basicity of CZA-4 are significantly improved during the hydrothermal synthesis under the continuous stirring and addition of CTAB, which positively impacts the CO2 conversion (14%) and methanol yield (7%). The CO2 conversion and methanol yield increases in the following order CZA-3 < CZA-1 < CZA-2 < CZA-4. In-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) analysis confirmed the formate-methoxy pathway for methanol formation. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
A sequence of ZnO/ZrO2-supported Fe/Cu catalysts were prepared and tested for methanol synthesis performance from CO2 using a high-pressure flow reactor. The Fe-containing catalysts showed a greater impact on methanol synthesis than the ZnO/ZrO2-supported Cu and Fe/Cu catalysts. The presence of the tetragonal-ZrO2 phase in the support is highly selective towards methanol formation. A catalyst containing 30 wt% Fe showed a uniform distribution of nanospheres and more oxygen vacancies. H2-TPR investigation revealed that the Fe catalyst offered strong interactions between iron oxides and ZrO2 support. At 250 °C and 30 bar, the Fe-incorporated catalyst showed a remarkable performance with 18.7 % CO2 conversion and 53.8 % methanol selectivity. The catalyst showed excellent thermo-chemical stability under time-on-stream conditions. In-situ DRIFTS analysis revealed the formation of formate and CO intermediates during methanol formation. A single-site kinetic model agrees well with the experimental results. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
The conversion of CO2 to methanol is a promising and economically profitable process for both CO2 emission reduction and energy renewability. Owing to the unique features of metal–organic frameworks (MOFs) in flexible tailorability of metal nodes and organic ligands, MOF-derived single-atom catalysts (SACs) have been demonstrated with excellent catalytic performance in catalysis. This review highlights the current developments of MOF-derived SACs for CO2 conversion to methanol, via electroreduction, photoreduction, and hydrogenation processes. The reaction pathways and mechanisms are discussed, with special emphasis on the structural advantages of MOF-derived SACs in altering the reaction pathway for CO2 conversion to methanol. Moreover, the innovative strategy for MOF-derived SACs designing through machine learning is introduced. Finally, the challenges and outlooks in futher development of MOF-derived SACs for CO2 conversion to methanol are discussed. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Carbon capture and carbon reuse in the chemical plants is one of the attractive prospective approaches to decrease the concerns about global warming and climate change. In the present study, is focused on the synthesis gas production from carbon dioxide in a methanol synthesis plant. In this regard, two methanol processes are proposed based on CO2 separation, recycling, and reforming. In the first scenario, CO2 is separated and recycled to the conventional reformer, while the process is equipped by a CO2 separation unit and dry methane reformer in the second scenario. The proposed processes are simulated and a sensitivity analysis is performed to investigated the effect of inputs on methanol productivity and carbon conversion. The operational parameters of proposed processes are optimized to enhance methanol productivity and CO2 conversion. Then, the processes are compared from energy efficiency, carbon efficiency, CO2 emission rate and methanol productivity viewpoints. The results showed that, in the second proposed scenario, methanol production rate approach to 5367 tons per day in comparison to 5030 tons per day for industrial unit. In addition, modification of conventional methanol process based on the second scenario could decrease CO2 emission rate about 56 tons per day. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Using the coprecipitation approach, the CuMgAl catalysts with varying Cu loadings (x-CMA, x = 4, 6, 8, 10, 12 wt.%) were created from hydrotalcite precursors and used in the CO2 hydrogenation to methanol process. In this work, XRD, N2 adsorption-desorption, TEM, H2-TPR, CO2-TPD, H2-TPD, XPS, and in situ DRIFTS characterization techniques were used to examine the structure and surface characteristics of x-CMA catalysts. The results demonstrated that an appropriate interaction between Cu and MgO was formed when the Cu loading was 10 wt%, which was conducive to the generation of more Cu-MgO interfaces, boosting the adsorption of CO2. The appropriate interaction between Cu and MgO also facilitates the production of Cu0, enhancing the dissociation of H2. The conversion of CO3 * and HCO3 * to HCOO * has been sped up by advancements in CO2 adsorption and H2 dissociation, which made the subsequent conversion to CH3OH easier. It also be found that 10-CMA obtained by the coprecipitation approach exhibited more Cu-MgO interfaces than 10-C/MA prepared by the impregnation method. At 2.5 MPa and 240 °C, the 10-CMA catalyst had the maximum STYCH3OH of 408.6 g⋅kgcat. −1⋅h −1 with the XCO2 of 14.1 % and SCH 3 OH of 93.9 %. The findings presented in this work may offer a fresh perspective on how to create high-efficiency catalysts that hydrogenate CO2 into methanol. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
On account of the superior performance of In2O3-ZrO2/SAPO-34 tandem catalyst in the direct synthesis of olefins from CO, CO2 and CO/CO2 mixture by hydrogenation, it is interesting to establish the conditions to avoid its deactivation due to the rapid coke deposition on SAPO-34. The co-feeding of H2O and/or methanol together with H2 + CO2/CO was studied in a packed bed reactor at: 400 °C, 30 bar; CO2/COx in the feed, 0–1; H2/COx in the feed, 1–3; and space time of 5 gcat h molC −1, quantifying the evolution with time on stream (up to 16 h) of CO2 and COx conversions and olefin, paraffin and CH4 yields. The effects of the co-feeding on coke content and its nature were determined by temperature programmed oxidation (TPO) analyses of the spent catalyst. The results highlighted the complex effect of the concentration of H2O and oxygenates (methanol/dimethyl ether (DME)) on the deactivation of SAPO-34 and on the products yields in the pseudo-steady state of the catalyst. Co-feeding H2O lessens coke deactivation, however, high H2O concentration leads to attenuate the acidity of SAPO-34, limiting the performance of the tandem catalyst (mainly in the CO2 conversion). Oxygenates co-feeding concentration limit value lies on its favoring effect for coke formation. In addition to this effect, the favorable attenuation of coke deactivation by the high H2 concentration (studied in runs with H2/COx ratio in the feed in the 1–3 range) plays a key role in the viability of the process, leading to a pseudo-steady catalyst state in which the activity is constant. The proven effect of H2O and methanol concentrations will be useful for establishing new catalysts and reaction conditions at which their presence in the reactor will attenuate deactivation. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Abstract The reaction routes for the CO2 hydrogenation to methanol over a series of Cu-Mn-La-Zr catalysts prepared by different methods, viz., CMLZ-CP by co-precipitation, CMLZ-S by sol-gel method and CMLZ-H by hydrothermal method, were comparatively investigated by in-situ DRIFT and H2-TPD characterization. The results indicate that the surface hydroxyl groups on these catalysts contribute to the CO2 hydrogenation to methanol and the reaction may follow the formate (HCOO*) and carboxylate (COOH*) routes. The carboxylate pathway is preferred for the reaction over the CMLZ-CP and CMLZ-H catalysts, whereas the formate pathway dominates in the reaction over the CMLZ-S catalyst. The CMLZ-CP catalyst shows the strongest ability to activate H2 and thus exhibits the highest CO2 conversion and methanol yield. In contrast, the CMLZ-H catalyst has high percentage of medium to strong basic sites and oxygen defects, which favor the hydrogenation of intermediate species to methanol, and thus exhibits the highest selectivity to methanol. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
This chapter addresses exergy analysis of a plausible solution to avail natural gas with high CO2 content from an offshore field for in situ production of methanol and electricity, whereas methanol production is conceived through partial oxidation for compactness. Three process flowsheets (NCA, AIR, EGR) are evaluated in Aspen HYSYS, all sharing same operating conditions in methanol production, which is modeled using experimental yields of gas-phase catalytic reactor. The configurations differ in combined cycle design conditions and whether a post-combustion CO2 absorption plant is included: (i) EGR utilizes a modified gas turbine to operate with exhaust-gas recirculation and further includes CO2 abatement by aqueous monoethanolamine; (ii) AIR also adopts CO2 capture but employs conventional gas turbine using excess air for cooling; (iii) NCA is similar to AIR but without CO2 capture. Results indicate that only 1.11% of feed gas elemental carbon is converted into methanol. In EGR and AIR, most of the remaining carbon leaves the process as supercritical CO2. EGR has the lowest emission factor (0.077kgCO2/kWh), as its capture penalty is 0.81%LHV lower than that of AIR case. EGR also evinces greater exergy performance than AIR, mostly in amine-plant and gas turbine process sub-systems, due to lower entropy generation and exergy loss through waste streams. Partial oxidation is the major cause of exergy destruction among methanol-related process sections, but its impact on exergy performance is much lower than that of power generation and CO2 capture, as a result of typically low conversion of the direct methane to methanol route.
| Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Cu/ZnO/Al2O3 catalysts have been widely applied as industrial catalysts for methanol synthesis from syngas, but suffers low activity for CO2 hydrogenation to methanol. This study establishes highly active Cu catalysts through modulation of the composite of Al2O3 and ZrO2 in Cu/ZnO-based catalysts. The composition of Al2O3 and ZrO2 impacts the Cu dispersion, exposed surface area of Cu, the Cu0/(Cu0+Cu+) ratio and surface basicity. An appropriate content of Al2O3 and ZrO2 presents the higher Cu surface area, desirable ratio of Cu0/(Cu0+Cu+) and moderate-strong basic sites for effective CO2 adsorption/activation, giving rise to higher space-time yield of methanol (up to 648 gCH3OH·kgcat −1·h−1) than the commercial Cu catalyst. STY of methanol can be correlated with Cu surface area and Cu0/(Cu0+Cu+) ratio under the investigated conditions. The mechanistic analysis demonstrates that surface formate and methoxy species are the major intermediates. The methanol formation principally follows the formate-methoxy intermediate pathway. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
This work describes the use of TiO2 nanotubes-based electrodes (TNT) modified with Cu2O nanostructures and gold nanoparticles for the photoelectroreduction of CO2 to produce value-added compounds. A thin layer of polydopamine was used as both an adherent agent and an electron transfer mediator, due to its π-conjugated electron system. The highest production yield was achieved using a TNT@PDA/Nc/Au40% electrode, with Faradaic efficiencies of 47.4% (110.5 μM cm−2) and 27.8% (50.4 μM cm−2) for methanol and methane, respectively. The performance of the photoelectrodes was shown to be Cu2O facet-dependent, with cubic structures leading to greater conversion of CO2 to methanol (43%) and methane (27%), compared to the octahedral morphology, while a higher percentage of metallic gold on the nanostructured Cu2O surface was mainly important for CH4 production. Density functional theory (DFT) calculations supported these findings, attributing the superior photoelectrocatalytic performance of the TNT@PDA/Nc/Au40% electrode for CH4 generation to the formation of an OCH3 intermediate bonded to Au atoms. Studies using isotope-labeling and analysis by gas chromatograph-mass (GC-MS) demonstrated that 13CO2 was the source for photoelectrocatalytic generation of 13CH3OH and 13CH3 13CH2OH. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
The hydrogenation of CO2 to methanol is a technology that converts a greenhouse gas into a valuable chemical compound that efficiently stores energy. Several alternatives to perform this process have been proposed, but they are either not thermally self-sufficient and depend on using external fuel, or the power usage per ton of methanol is insufficiently optimized, or part of the raw materials must be purged and therefore there is a loss of methanol yield. This original study aims to develop a novel thermally self-sufficient process for e-methanol production (at practically 100% yield along with water by-product of 0.37 kgwater/kgproduct) that only uses green electricity. The main innovation of the process is an effective thermally self-sufficient heat-integration scheme that only needs 0.0059 m3 water/kgmethanol combined with using a dividing wall column to recover the unreacted CO2 and obtain high purity methanol. In addition, the pressure reduction in the reaction-separation loop is limited to the pressure drop of the circuit to minimize the overall green electricity use to only 656 kWh per ton methanol, resulting in net CO2 emissions of −1.13 kgCO2/kgMeOH or 0.78 kgCO2/kgMeOH when the plant operates with green or grey hydrogen and electricity, respectively. Finally, the operating pressure in the reactor is optimized at 65 bar to minimize the total annualized cost. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
The CuO-ZnO-Al2O3/protonated Y-type zeolite (CZA/HYZ) catalysts were prepared via co-precipitation method and employed in a two-stage CO2 conversion process using a dual fixed–bed column at different temperatures and 50 bar. Catalytic components of CZA/HYZ were copper species that have been identified with XPS. Remarkably, the fine structures of CZA/HYZ catalysts metal atoms were confirmed with XANES and EXAFS spectra. Molecular configurations of catalytic species in CZA/HYZ catalyst simulated from the XANES/EXAFS spectra-analyzed fine structural parameters were schematically displayed. The optimal catalytic performances of CZA/HYZ (CH3OH conversion=78.0%, CH3OCH3/HCOOH selectivity=91.7%/8.3%, CH3OCH3/HCOOH yield=71.5%/6.5%) were achieved at 250 ºC. The Arrhenius equation and a pseudo-first-order/second-order model were used to evaluate the activation energies and rate constants of CH3OH and CH3OCH3 formations at various catalytic temperatures. The low activation energies (2.720 and 1.160 kJ mol−1) and Gibbs energies (3.26 and −40.00 kJ mol−1) of CH3OH and CH3OCH3 formations at 250 ºC, demonstrated that their spontaneities were remarkably improved via CZA/HYZ, respectively. The total income from a 10–ton per day (10–TPD) for a petrochemical refinery plant waste gas utility process was USD $43,557d−1, as well a payback of 3.23 years, based on cost evaluation. The proposed process provides a continuous two-step process for manufacturing high–value-added chemicals using industrial CO2 emitted and syngas. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
The behaviour of Pd deposited on Ga2O3 and In2O3 by CVI is compared for the hydrogenation of CO2 to methanol. Ga2O3 alone is inactive, but In2O3 has good conversion, and selectivity as high as 89 % to CH3OH. The addition of Pd to the catalysts had relatively little effect for In2O3, but in contrast, the addition of Pd to Ga2O3, has a very big effect, inducing high activity and selectivity to methanol. Both oxides form Pd intermetallics - Pd2In3 and Pd2Ga. However, for the In catalysts there is also a thick (∼3 nm) overlayer of the oxide, while for the Ga catalyst there was no such overlayer. Hence this is why addition of Pd to the Indium catalysts has relatively little effect on performance compared with Ga. Furthermore, the effect of Pd and Zn co-deposition on Ga₂O₃ and In₂O₃ was investigated, as well as the effect of the support morphology. Upon co-deposition of Pd and Zn, and after reduction, the Pd2In3 catalyst remains phase stable, whereas the Pd2Ga alloy is replaced by PdZn, and is improved in methanol yield. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
CO2 capture and utilization are an effective solution to the problem of CO2 emissions, and a combination of ammonia-based CO2 capture and its use for methanol production is a highly feasible strategy. However, the uses of conventional technologies have resulted in a high demand for energy, with limited use of hydrogen. To address these problems, an innovative strategy is proposed and demonstrated in this study that enhances the conventional design, i.e., to use ammonia-based CO2 capture with double tower absorption and solvent split, along with wet hydrogen for methanol production at industrial scale. The process is further improved through a multi-criteria assessment that considered the CO2 capture rate, NH3 loss rate, CO2 conversion rate, and energy saving factors, in which the latter is based on two components, namely the reboiler duty and the condenser duty. Moreover, an exergy analysis method is used to optimize the improved process, and a highly efficient integrated process is finally established. It has been found that the use of a double-tower absorption process ensures high rates of CO2 capture and low rates of NH3 loss. Additionally, adjusting the molar ratio of H2 to CO2 leads to an impressive 8% increase in the CO2 conversion rate, reaching 25%. In terms of energy savings, the average reboiler duty was reduced from 13.39 to 11.85 MJ/kgCO2, i.e., by 11.50%; while the condenser duty was reduced by 11.36%; both contributed to the overall energy savings. In the I-ACCMP process, the total exergy loss is 437.24 kW, of which the exergy loss of the heat exchangers accounts for 16%, and the desorption tower (DES) accounts for 48%. After optimization, the exergy loss of the heat exchangers decreases from 70.02 kW to 40.45 kW, the exergy loss of the DES decreases from 209.29 kW to 180.91 kW, and the reboiler duty is reduced from 10.60 MJ/kgCO2 to 7.71 MJ/kgCO2. The total exergy loss decreases from 437.24 kW to 372.68 kW, which is a reduction by 14.8%. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Efficient conversion of CO2 to methanol using a renewable source of H2 is a feasible strategy to achieve the goal of carbon neutrality. A qualified InNi3C0.5/Fe3O4 catalyst system was developed by the co-precipitation method. The effects of catalyst preparation were investigated systematically on the catalyst performance. Well-formation of InNi3C0.5 nano-intermetallic is essential to a high activity/selectivity of catalyst, which is strongly dependent on the catalyst calcination/carburization temperatures. The catalytic-relevant electronic metal-support interaction is tightly linked with the InNi3C0.5 particle size that is tunable with In-loading. The 5InNi3C0.5/Fe3O4-400/425 catalyst (5 wt% In, calcined at 400 °C and carburized at 425 °C), with a high turnover frequency of 513 h−1 and promising stability, achieves 12.3 % or 6.8 % CO2 conversion and 95.6 % or > 99.8 % methanol selectivity without CH4 formation at 250 or 200 °C, 4.0 MPa and 12,000 mL gcat −1h−1, for H2/CO2 = 5/1. A high methanol space–time-yield of 2.62 gMeOH gcat −1h−1 is obtainable at 250 °C and 6.0 MPa. A pathway of CO2-to-CO*-to-HCO*-to-CH2O*-to-CH2OH*-to-CH3OH* is proposed for the CO2 hydrogenation to methanol over our InNi3C0.5/Fe3O4 catalyst. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Using reduced nicotinamide adenine dinucleotide (NADH) as cofactor, CO2 can be reduced into methanol catalyzed by formate dehydrogenase (FDH), formaldehyde dehydrogenase (FaldDH) and alcohol dehydrogenase (ADH). However, poor stability of soluble enzymes and the stoichiometric consumption of NADH are major restrictions. Herein, the three enzymes were co-immobilized on a hollow fiber membrane (HFM) module, which was then integrated with a photocatalytic NADH regeneration system to constitute a photo−enzyme coupled system (PECS) for the synthesis of methanol. First, the multi-enzyme immobilization process was optimized and the enzyme-bearing membrane was characterized. Then, the influencing factors of PECS were investigated. The results show that using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS) as the activators, a total immobilization efficiency of 64.5% could be obtained, which was superior to sequential immobilization. Under the optimum immobilization conditions, the specific activity reached 0.397 mmol g−1 h−1. For the PECS, NADH concentration, pH value and manipulation parameters had great impacts on the synthesis of methanol. With 10 mmol L−1 NAD+ and H2O as electron donor, the methanol yield after 5 h could reach 38.6%, 3.81 times that of enzyme-catalyzed system, proving the PECS was feasible for a continuous synthesis of methanol. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
The escalating emission of CO2 has caused a significant environmental impact. Hydrogenation of CO2 to methanol stands as the primary objective in the liquid sunlight vision, aiming to mitigate CO2 emissions. CuZn-based transition metal catalysts, known for their cost-effectiveness, demonstrate commendable catalytic performance at moderate temperatures and pressures, showcasing considerable potential in industrial applications. Consequently, a series of catalysts, composed of CuZn-based species supported on CeO2 with strategically introduced appropriate oxygen vacancies, were meticulously prepared. It worth to noting that the size of Cu was precisely tuned, along with the enhanced ability to the adsorption and activation of CO2 and H2. As a result, the optimal CuZn/CeO2 catalyst exhibits high methanol formation rate, recording at 433.4 gMeOH kgcat −1 h−1 with selectivity of 68.5% at 260 °C and 3 MPa. Simultaneously, the reaction path and the evolution of intermediates in CO2 hydrogenation was thoroughly delineated. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
First-principles calculations were performed to explore the detailed reaction mechanisms of CO2 conversion to methanol over two size-selected copper clusters supported on the TiC(001) surface, in which three potential routes including the formate, the reverse water-gas-shift (RWGS) + CO-hydrogenation, and the CO bond cleavage pathways were considered. Our findings show that the adsorption and migration of hydrogen atoms have obvious impact on the catalytic activity for CO2 conversion. The limited size of the active site of small Cu cluster with a planar configuration results in that the formate route is difficult to occur because the creation of H2COOH* intermediate requires the spillover of H atoms from the substrate to the active center by overcoming a high kinetic barrier. On the contrary, the polyhedron structure in the large Cu cluster can act as a reservoir for the hydrogen adsorption, making it possible to produce methanol via the formate pathway. Although the RWGS + CO-hydrogenation pathway is identified as the preferred reaction pathway on both surfaces, the relatively strong binding of hydrogen on the large copper cluster causes difficulty in the migration of H toward the reaction intermediate. The results of microkinetic simulations indicate that the rate-limiting steps are sensitive to cluster size, and small Cu cluster exhibits better catalytic activity for the conversion of CO2 to CH3OH. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
null | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | null |
Hydrogenating CO2 to methanol with high yields and selectivity remains a kinetic challenge. We report ternary Cu-Ga-Zr catalysts with promising performances. Methanol productivity and selectivity were highest on coprecipitated samples containing approximately 20wt% of each metal. At 7% isoconversion, this ternary system was more selective to methanol (60 ± 1%) than CuZrOx (51 ± 1%) and CuGaOx (53 ± 3%) at the same Cu loading. We uncover the importance of the Cu/Zr interface for CO2 adsorption, Cu/Ga interface for H adsorption, and metallic Cu for H–H dissociation. Methanol formation on these catalysts was found to be first order in H2, implying the reaction was likely to be rate-limited by hydrogen activation. In fact, the methanol space-time yield correlated linearly with the H2/D2 exchange rate. We propose a catalytic pathway wherein the production of the byproduct CO is hindered by the presence of adsorbed H. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Electrocatalytic (EC) and thermocatalytic (TC) conversion of CO2 to methanol are promising carbon capture and utilization technologies. Herein, these CO2-to-methanol conversion processes are analysed in terms of technical, environmental and economic feasibility. To this purpose, the catalytic performance of the same catalyst (CuO/ZnO/Al2O3) was evaluated in both EC and TC processes. Here is showed for the first time that this catalyst is (apart from TC route) also able to generate methanol through CO2 EC reduction. This work presents lab scale tests, scaled-up simulations and evaluates the environmental and economic performance of these processes. The carbon footprint of the TC and EC processes, scaled-up to the same productivity of ~ 3 kg/h methanol, scored ~ 8 kgCO2 eq/kgCH3OH. Strategies to reduce this impact are presented, such as improving the current density of the EC cell (i.e. 200 mA/cm2 results in a reduction of 68% to 2.72 kgCO2 eq/kgCH3OH) and the availability of 100% renewable electricity (saving up to 62% carbon footprint of both processes). Considering an effective allocation of the methanol productivity on a real market scenario, both the TC and EC processes would start to be economically competitive at methanol productivities > 19.1 kg/h and 3.3 kg/h, respectively. Moreover, if O2 valorisation, a low price of the renewable electricity and a carbon tax are considered, the economic profitability will rise; e.g. the minimum levelised cost of product (LCOP of 1.45 €/kg and 1.67 €/kg, respectively) could be reduced by 53%. Finally, our results pointed out that the CO2 electroreduction process must be optimized (e.g. improving catalysts performance and EC cell design reducing mass transfer limitations) to achieve industrially relevant rates and the maturity of the thermocatalytic technology. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
CO2 conversions to methanol and subsequent chemicals are of great significance on facing the global climate crisis. High dispersions of active components are preferred, whereas it’s hard to realize using conventional methods. Herein, a novel strategy was adopted to encapsulate Cu-ZnOx species in zeolite frameworks to acquire high activity. Zeolite 13X regulated Cu-ZnOx catalysts (Cu-ZnOx/13X) with different Cu:Zn ratios are therefore developed and show considerable surface areas and pore volumes. The typical Cu-ZnOx/13X catalyst exhibits remarkable property stability even after 180 h of continuous reaction and performs dramatically within wide temperature and pressure ranges with high methanol selectivity. Further analyses of the mechanism suggest suitable microstructures of Cu-ZnOx/13X catalysts. The Cu activity is also promoted to achieve an approximately 27 % higher turnover frequency than the reported benchmark Cu–ZnO–Al2O3 catalyst. The present work provides a distinctive solution for catalyst construction, which we believe can give important insights into efficient CO2 utilization. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
The conversion of carbon oxides (CO + CO2) to methanol is promising enough in concomitant decrease in greenhouse effect along with the mitigation of energy crisis. However, the process still confronts low levels of CO2 conversion and development of highly efficient catalyst is a bid challenge. In the present work, a syngas feed rich in CO2 was employed to produce methanol over a streak of La promoted Cu/ZnO/MgO catalysts where a harmonized synergy between the La and active Cu sites as a function of La content is reported. XRD analysis of Cu/ZnO/MgO/La2O3 precursors indicated the relative concentration of aurichalcite or malachite galleries. The optimized catalyst (2.5 mol% La) demonstrated the amplified population of malachite phase whereas suppression in aurichalcite phase. Presence of mixed phase precursor reflected well in Cu dispersion, small sized stable Cu particles and improved methanol synthesis activity with marginal deterioration in catalytic efficiency over 60 h on stream. A thorough investigation revealed that introducing La not only generated the required moderate basic sites but also enriched the catalytic surface with active Cu. XPS results indicated that La regulates interaction between Cu2+ and La3+ species, ultimately modifying the surface Cu/Zn ratio. CZ-M17.5La2.5 catalyst showed the highest carbon conversion with a methanol selectivity of 72.2% at 260 °C. This proves that La plays a crucial role towards methanol synthesis when blend of CO/CO2 is used as a feed. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
As global energy demand continues to increase and global climate change issues caused by greenhouse gas emissions gradually heat up, the effective conversion of carbon dioxide into high value-added methanol has become a key challenge in the energy and environmental fields. However, due to the chemical inertness of CO2 molecules, it is difficult to activate CO2 at low temperatures, resulting in extremely low conversion rates. Although increasing the reaction temperature is beneficial for the conversion of CO2, there is also competition in the reverse water gas reaction, resulting in lower methanol selectivity. Therefore, developing efficient catalysts is the key to improving CO2 conversion rate and methanol selectivity. In this work, we used zirconium-based UIO-66 metal-organic framework as a precursor, replaced the original terephthalic acid ligand with thermally unstable aminoterephthalic acid, and supported Cu on the MOF precursor by equal volume impregnation method. After heat treatment, the Cu/ZrO2-DM catalyst was prepared. The catalyst was compared with Cu/ZrO2 catalyst prepared by co-precipitation method, hydrothermal method and unmodified Cu/ZrO2-D catalyst. The Cu/ZrO2-DM catalyst exhibited the highest CO2 conversion and methanol selectivity in the hydrogenation reaction, reaching 13.95% and 90.78%, respectively. The main reason is attributed to the large specific surface area of the copper-based catalyst derived from MOF materials, the good dispersion of the active center and the strong interaction between Cu and the precursor. This work may provide a new perspective for the design and synthesis of related catalytic materials for efficient CO2 hydrogenation to methanol. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Methanol as a clean energy source is one of the most important industrial petrochemical products that it is used as a fuel, solvent, and intermediate substance for other component production. Methanol is directly synthesized from CO2 in the direct process, while in the indirect one, CO2 is converted to CO in a water gas shift reactor as an intermediate. In this research, both direct and indirect processes are designed and simulated via Aspen Plus simulator at steady state condition for comparing not only their efficiencies, but also their economic and environmental analysis for the first time. The optimum operating conditions of processes are obtained to achieve the maximum methanol production at a fixed feed rate of 228,417 tons/year CO2 waste gas supply. Furthermore, the best process is selected by TOPSIS decision making method by comparing the capital cost and environment issues of the direct and indirect processes. The results show that direct methanol synthesis has a superior environmental and financial efficiency compared to the indirect process as the fixed capital investment is 506 million USD for the direct process and 578 million USD for the indirect method. This is while the net profit amount is opposite, 132 million USD for direct and 135 million USD for indirect processes with the payback periods of about 7 and 8 years for the direct and indirect processes, respectively. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Single atom catalysts (SACs) have received great attention due to their promising catalytic activity and sustainability. In this regard, the catalytic activity toward CO2 conversion reaction can be efficiently improved by the addition of single transition metal anchored on the 2D MoS2 monolayer. In this work, we explore the potential utilization of Ru@MoS2 as a promising SAC for the CO2 reduction reaction (CO2RR) by using first-principles simulations. The stability of the so-formed SAC was evaluated in terms of binding energy, and the reaction paths leading to the production of CO and methanol was investigated. Our results show the great potential of Ru@MoS2 as SAC for the CO2 conversion to methanol as the main product, and contribute to shed light on the complex reaction mechanism aiming at the development of more efficient catalytic systems. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
The selectivity of methanol conversion to aromatics on Zn/ZSM-5 is often limited, mainly because the hydrogen removed during the process combines with low-carbon olefin intermediates to regenerate alkanes and reduce the effective utilization of carbon atoms. Herein, CO2 is added to the methanol aromatization reaction as a receptor that consumes hydrogen in situ, which reduces the hydrogen transfer reaction and improves the selectivity of aromatics. It is proposed that aromatic selectivity under CO2 atmosphere is determined by the chemical state of Zn species. Specifically, ZnO converts CO2 and consumes hydrogen, and ZnOH+ promotes methanol aromatization. Under the same conditions, aromatic selectivity of 3ZnZ18-IM under CO2 atmosphere can reach 85.2 %, which is much higher than that of 71.4 % under N2 atmosphere. This study provides a new strategy for methanol to aromatics (MTA) reaction, which has a positive impact on solving the energy and environmental problems in the production of aromatics. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Compared to the Run+ (where n = 2 or 3) homogenous catalysts that convert CO2 into methanol, 3d metal catalysts (such as Fen+, Con+, and Mnn+) exhibit poor activity due to catalyst poisoning and/or instability. Overcoming the hurdles observed in the case of 3d metal catalysts, in this article, we have unveiled a robust, cheap, and abundant Co(II) catalyst ([Li(DME)3][Co(L1)3]; 1, where L1 = 2,6-diisopropylanilide) which efficiently converts the CO2 into its methanol equivalent (B(OMe)3) in the presence of NaBH4, which upon hydrolysis yields methanol under mild conditions (0.1 bar CO2 and 60 °C) with the unprecedented TON and TOF of 11,171 and 508 h−1, respectively compared to any 3d metal catalyst reported to date. Further, we noticed that the activity of 1 was maintained for weeks, which is reflected in the overall TON of 54,000 obtained after 7 cycles. Moreover, we have shown that 1 can selectively reduce CO2 into methanol even from the “vehicle exhaust” directly. Systematic investigations were performed to shed light on the likely intermediates involved in the catalytic cycle, based on that we have proposed a mechanism for this reaction. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Due to the intervention from the water-gas shift (WGS) reaction (or the reverse one (RWGS)), the hydrogenation of CO (or CO2) into alcohols and hydrocarbons often displays rather high selectivity to CO2 (or CO), which makes it rather puzzling to evaluate such conversion processes by using the relatively low selectivity to the target products. Herein, a thermodynamic consideration is made to elaborately evaluate the effect of the WGS/RWGS reaction on the hydrogenation of CO, CO2, and their mixture to typical alcohols (e.g. methanol) and hydrocarbons (e.g. ethene). The results indicate that for the hydrogenation of CO (or CO2), although the WGS (or RWGS) reaction, acting as a communicating vessel connecting CO and CO2, may have a severe influence on the equilibrium conversion of CO (or CO2), forming a large amount of CO2 (or CO), it only has a relatively minor impact on the C-based equilibrium yield of the target alcohol/hydrocarbon product. The hydrogenation of CO shows a higher C-based equilibrium yield for the target product than the hydrogenation of CO2, while the overall C-based equilibrium yield of target product for the hydrogenation of the CO and CO2 mixture just lies in between. For the hydrogenation of the CO and CO2 mixture, although the equilibrium conversion of CO and CO2 may vary greatly with the change in the feed composition, the relation between the overall C-based equilibrium yield of the target product and the feed composition is rather simple; that is, the overall C-based equilibrium yield of alcohol/hydrocarbon product decreases almost lineally with the increase of the CO2/(CO + CO2) molar ratio in the feed. These results strongly suggest that the mixture of CO and CO2 is credible in practice for the production of alcohols and hydrocarbons through hydrogenation, where the overall C-based yield should be used as the major index for the hydrogenation of CO, CO2, and their mixture. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Methanol and DME are highly efficient fuels and relevant building blocks that can be synthesized by CO2 hydrogenation. While several alternatives for methanol production by CO2 hydrogenation have already been developed at a commercial scale, DME production is still based on methanol dehydration. In this sense, the development of bifunctional methanol synthesis/dehydration catalysts is a clear opportunity for the simultaneous coproduction of methanol and DME in a single-step process. Although a few alternatives for DME-methanol coproduction have been proposed, either they need external fuels or refrigerants, or part of the CO2 used as raw material is purged, resulting in a loss of methanol and DME yields. This work presents a novel thermally self-sufficient process that hydrogenates CO2 into methanol and DME in a single reactor at 100 % yield (only water as a byproduct at 0.94 kgwater/kgproduct), that only consumes air, cooling water (0.006 m3 water/kgproducts) and electricity (net CO2 emissions of −1.20 or 0.64 kgCO2eq/kgproducts when the plant is operated with green or grey electricity, respectively). The innovative design, based on the combination of a top-divided wall column, an integrated heat network, and limited pressure drop in the reaction-separation loop, results in a thermally self-sufficient process that uses only 0.76 kWh per kg products. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Aerosol-based continuous synthesis for metal–organic framework (MOF) derived catalyst materials, in combination with real-time gas-phase electrophoresis for material characterization, is demonstrated for methanol production via combined CO2 and CO hydrogenation. Cu-based and Zn-based MOF colloids were prepared as the templates for the synthesis of Cu-ZnO catalysts supported on either Al2O3 or CeO2. The results showed the incorporation of real-time gas-phase electrophoresis enabled traceability of continuous catalyst production. Optimal selectivity of 90.52 %, and space–time yield of 7.50 mmol gcat −1h−1 were achievable in the methanol production. Interestingly, the space–time yield of methanol was shown to be linearly proportional to metal surface area of the catalyst. This study demonstrated significant advances in the continuous production of MOF-derived hybrid catalysts through aerosol-phase synthesis with real-time characterization. The high catalytic performance of the developed materials in the combined CO2 and CO hydrogenation to methanol bears promise for applications in the field of CO2 utilization. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
High dispersion of active metal is always approved for better catalytic performance in CO2 hydrogenation to methanol. Herein, a strategy was proposed to encapsulate copper nanoparticles in supercages of zeolite 13X, and hence the growth of copper nanoparticles can be controlled. In the present work, catalysts were prepared using ion-exchange and hydrogen reduction at a tiny positive pressure. The results show that as-synthesized catalyst consists of metallic copper and FAU-type zeolite. Excessive amount of copper will destroy zeolite frameworks, and the amount of 5.9 at% is appropriate for considerable BET surface area and ideal copper dispersion. Meanwhile, copper nanoparticles may grow outside from zeolite at high reduction temperatures (≥220 °C), resulting in serious surface area decline and metallic copper agglomeration. Afterwards catalytic tests reveal good stability of the optimal CX-220 catalyst in continuous reactions. The CX-220 achieves remarkably high methanol selectivity of ≥ 95% within wide ranges of reaction temperatures and reaction pressures. Further analyses reveal that the encapsulation of copper nanoparticles reduces micropores and enriches mesopores in zeolite. The apparent activation energy for methanol synthesis over CX-220 catalyst has been lowered to a very low level because of the unique microstructure, and thus the methanol synthesis reaction is dominant in CO2 hydrogenation for dramatic methanol selectivity. Therefore, this work gives important insights and applicable routes for catalysts analyses of CO2 hydrogenation to methanol. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Methanol synthesis by CO2 hydrogenation is a key process in a sustainable methanol-based economy. Copper silicate (CuSiO3) is considered as efficient for hydrogenation of C-O/CO bonds due to the synergistic effect from its unique dual-sites of Cu0-Cu+. However, it still confronts great obstacles of poor CO2 conversion and low methanol selectivity. Herein, we designed a core-shell CuSiO3 nanoreactor by hydrothermal method, the cavity of which between core and shell provided the reaction space for CO2 and H2 in CO2 hydrogenation. Interestingly, the cavity of the nanoreactor could be tuned by the hydrothermal time, and the product selectivity altered accordingly. Intrinsically, because of the spatial restriction effect of reactants, the reactant especially hydrogen can be enriched on the concave surface of nanotubes and hollow spheres, leading to a favorable activity. Furthermore, the longer diffusion path derived from the increased cavity volume would cause a deep hydrogenation to CH4. Based on this, we chose the nanoreactor with suitable cavity volume to impregnate copper nanoparticles to increased the active sites and regulate the ratio of Cu0/Cu+, achieving remarkable catalytic activity (the conversion of CO2 is 19.7% and yield of methanol reaches up to ∼18%). Moreover, the copper nanoparticles could be anchored by the core and shells, contributed to an excellent stability of the catalytic system (>120 h). | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Addressing the major challenge of global warming by implementing a circular carbon cycle involving CO2 conversion is currently an urgent priority for a more sustainable future. The design of efficient, stable, cheap and eco-friendly systems for such purpose is a remarkable challenge. This study reports an unprecedented metal-free, co-catalyst-free orange peel waste–derived carbon nanodot highly active and selective system for the photoreduction of CO2 into methanol. The waste-derived photocatalyst exhibited a maximum methanol production rate of 416.6 µmolMeOH.gcat -1.h−1 and a highly stable methanol production rate of 12.9 µmolMeOH.gcat -1.h−1 after 72 h. This work proposes a successful waste-to-fuel strategy that combines the valorization of orange peel waste and CO2 conversion for the synthesis of green methanol. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
The Cu/Zn/Al precursor by coprecipitation was treated with formic acid and then calcined in N2 to obtain Cu-ZnO-Al2O3 catalyst (CZA) for the CO2 hydrogenation to methanol. XRD, BET, TG-DSC, SEM, H2-TPR, N2O titration, XPS-AES and CO2-TPD characterization techniques were used to analyze the phase composition, structural properties of the catalyst, the Cu specific surface area, the dispersion and valence of the Cu species. The results showed that the formic acid treatment tuned the ratio of Cu+ and Cu0, increased the number of medium-strong base sites in the catalyst, and raised the selectivity of methanol. Under reaction conditions of W/F(H2/CO2=70/23)=10 g·h/mol, t=200 °C and p=3 MPa, using Cu-ZnO-Al2O3 treated under HCOOH/Cu/(molar ratio)=0.8, the CO2 conversion and the methanol selectivity were 6.7% and 76.3%, respectively. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Kinetic aspects of the operating parameters for the catalytic conversion of H2/CO2 to methanol over two novel catalysts were evaluated to understand the effect of the polymorphic ZrO2 phase composed of Cu0/+-ZnO sites at the atomic level and its impact on the reaction mechanism. The catalysts were characterized by in situ and ex-situ XRD, N2 adsorption/desorption isotherms, FRX, TPR, TPD-N2O, in situ XANES, TPD-CO2, and in situ DRIFTS techniques. The influence of different reaction variables such as the GHSV, temperature, pressure, and H2/CO2 ratio were studied using a fixed bed continuous plug flow reactor. The Cu-ZnO catalyst supported on the tetragonal zirconia polymorph exhibited the highest methanol yield due to the lower activation energy when compared to the catalyst with a greater amount of the monoclinic phase. In addition, the catalysts were reused for 8 cycles of 6 h to evaluate their stability, which can translate into lower costs for large-scale methanol production. The estimation of the kinetic parameters for the Cu-Zn oxide catalysts supported on ZrO2 polymorphs was important to understand the reaction mechanism, as well as to provide useful information for scaling up the process. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
This study developed a novel design guideline for CO2 to methanol (CTM) conversion process supported by a generic model for various types of bed reactors (BRs) as the process economics depends on BR selection. Using commercially feasible BRs, such as fixed bed (FxB), bubbling fluidized bed (BFB), turbulent fluidized bed (TFB), and fast fluidized bed (FFB), we analyzed the CTM process to determine the optimum recycle ratio, gas velocity over the minimum fluidization velocity (GV/MFV) ratio, inlet reactor pressure, and inlet reactor temperature. At full recycle of unconverted gas, the optimum GV/MFV ratio was 0.1 for the process using an FxB reactor, while conversion using a TFB reactor was a better option than those using BFB and FFB reactors at the GV/MFV ratio of 7.03. Meanwhile, the CTM process using various types of BRs performed the minimum cost at 55 bar for reactor pressure and 498 K for reactor temperature. Owing to the competitiveness of the FxB and TFB reactors at small and large CO2 source rates, respectively, further analysis of the optimal conditions was conducted for these reactors, and a design guideline for the CTM process using these reactors was developed. The effect of the uncertainty parameters on the process design was analyzed to determine the CO2 source rate, green H2 cost, and CO2 cost. The design guideline was suggested for proper CTM process at different uncertainty values of CO2 source rate and material costs under a vision up to 2050 (for net-zero emissions). Finally, the design guideline integrated with methanol purifiers highlighted its reliability for high-purity methanol production. The production cost (∼340 $/tMeOH at 2050) for green methanol (mitigated −0.78 to −0.83 kgCO2/kgMeOH) was highly competitive with the cost (310 to 520 $/tMeOH) of traditional methanol production emitted 1.6 to 2.971 kgCO2/kgMeOH. The developed guidelines are useful for the design, operation, and decision-making of the CTM process. In addition, the developed models for BRs can contribute to other CO2 utilization processes. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
In this work, sequential incipient wetness impregnation method was used to synthesize Cu/Al2O3, Cu/Na2O/Al2O3 and Cu/CaO/Al2O3 catalysts in different compositions for CO2 conversion to value-added products. Synthesized catalysts were characterized using various analytical techniques and their performances for CO2 catalytic conversion were tested in a high-pressure packed bed reactor under reaction conditions of P = 60 bars, T = 300 °C, and H2/CO2 = 3. The obtained results revealed that the type of adsorbent had a significant impact on CO2 conversion, with CaO-containing catalyst being more efficient for methanol selectivity. Increased Cu content from 10 wt% to 30 wt% with fixed CaO content of 10 wt% resulted in a small increase in CO2 conversion where the highest CO2 conversion of 16.44% and the highest methanol selectivity (17.75%) were obtained for catalyst containing 20 wt% of copper. The best performing catalyst was further promoted using 0.5 wt% Rh promoter which improved both methanol selectivity and space time yield to 23.2% and 0.08 gMeOHgcat −1h−1, respectively. The comparative high performance of the Rh-promoted catalyst was attributed to smaller metal oxide particle size with uniform dispersion, presence of effective hydrogen spill over, moderate basic sites, surface defects and presence of induced copper species. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
In this work, we developed an effective approach for the conversion of CO2 by incorporating the electrified combined reforming reactor (E-CRM). The process simulation and life cycle assessment (LCA) of the proposed process are conducted considering a variety of recycling ratios of the unreacted syngas to the main reformer using Aspen Plus software. The simulation results show that the electrification of the proposed reforming process can significantly improve the overall efficiency of the process compared to a reference process. The key factors such as hydrogen demand (88.4 % reduction), net electricity consumption (17 % reduction), thermal efficiency (16.7 % increase), and methanol production (7.5 % increase) are improved. Furthermore, the LCA of the proposed process is conducted using openLCA software and results are compared with those of the CO2 hydrogenation and conventional methanol production processes for various geographical locations in Canada. The LCA results showed that the E-CRM with 90 recycling of unreacted gases (E-CRM-90) is an environmentally attractive option with the lowest greenhouse gas emissions when the carbon intensity of the electricity is equal to or lower than that of the average value in Canada. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Non-relevant |
In this study, a spray-drying approach is presented to develop (1) Cu-based metal–organic framework (Cu-MOF) supported on aluminum oxide nanoparticle cluster and (2) its derivedCu-ZnO/Al2O3 hybrid catalyst for combined (CO + CO2) hydrogenation to methanol. The results show superior high space time yield, 23.14 mmol gcat-1h−1, and selectivity to methanol (85%) were achievable under a moderate-pressure (30 bar) and relatively low-temperature (220 °C) operation. Incorporation of ZnO and Al2O3 (i.e., in the form of nanoparticle cluster) enhanced the dispersion and the redox ability of Cu in the MOF-derived catalyst, both of which were critical factors to the catalytic activity toward the combined hydrogenation of CO2 and CO to methanol. An optimal performance, in terms of the methanol yield, was achieved by using the catalyst with a Cu/Zn molar ratio of 2 and partially reduction by H2 at a relatively lower temperature (300 °C). The work demonstrates a new route for the design of MOF-derived catalyst by using an aerosol-assisted synthesis approach, showing promise for the catalysis of a variety of chemical reactions in the field of CO2 capture and utilization. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
CO2 hydrogenation to methanol is a pivotal route for CO2 conversion and fixation, with Cu-based catalysts currently exhibiting superior performance. However, the majority of reported Cu-based catalysts lack a comparison with commercial Cu-based catalysts employed in methanol synthesis from syngas. Furthermore, there are limited research works on the effect of sizes of Cu particle to catalyst performance, especially for inverse Cu catalysts, which is a promising catalyst with highly active ZrO
x
-Cu interface. By precisely controlling the synthesis method to regulate the particle size of Cu in Zr-Cu inverse catalysts, we illustrated that the copper surface area plays a predominant role in influencing catalytic activity. Additionally, the presence of highly dispersed ZrO
x
clusters on the surface of Cu particles not only enhances the space-time yield of methanol but also serves to segregate Cu particles and to inhibit sintering. The unique structure of Zr-Cu inverse catalysts leads to comparable reactivity to the commercial Cu catalysts.
| Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Converting carbon dioxide (CO2) into high-quality methanol to alleviate the energy crisis is a promising strategy. However, as a traditional catalyst for CO2 hydrogenation to methanol, Cu/ZnO exhibits low CO2 conversion and low methanol selectivity at low temperature. In order to improve the catalytic performance of CO2 hydrogenation to methanol, Co3O4 was introduced to form Co3O4-CuO-ZnO with flower-like structure, and then diamond-shaped ZIF-8 particles with large specific surface area and rich oxygen vacancies were synthesized on the surface of Co3O4-CuO-ZnO by hydrothermal method. A series of characterizations showed that the synthesis of ZIF-8 greatly increased the specific surface area of the catalyst. The oxygen vacancy is the site of CO2 adsorption and activation, and stabilizes the reaction intermediate, which promotes the conversion of CO2 and the formation of methanol. The introduction of Co promotes the formation of the alloy phase, enhances the interaction between the metals, makes the active center more dispersed, reduces the sintering of the catalyst, and thus exhibits better catalytic performance. Among co-precipitated CuO-ZnO, hydrothermal CuO-ZnO, CuO-ZnO@ZIF-8, Co3O4-CuO-ZnO and Co3O4-CuO-ZnO@ZIF-8 catalysts, Co3O4-CuO-ZnO@ZIF-8 exhibits the best catalytic performance (CO2 conversion 16.06% and CH3OH selectivity 94.58%). Based on the above design, ZIF-8 and Co3O4 synergistic CuO-ZnO catalyst effectively improved CO2 conversion and CH3OH selectivity. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
In this study, an innovative Cu/Zn/Al/Zr catalyst for the conversion of CO2 and H2 into methanol is tested at laboratory scale (0.5 g of catalyst into a cylindrical fixed bed reactor, with 9.1 mm internal diameter). Fourteen experimental tests are performed under isothermal conditions (T = 250 °C), covering a range of pressure (3.0–7.0 MPa), Gas Hourly Space Velocity (4000–13,000 h-1) and H2/CO2 molar ratio (between 3 and 6) relevant to industrial applications, with or without CO in the feed mixture, with flow-rates ranging between 200 and 650 NmL min-1. Based on the established Graaf’s kinetic model, new kinetic parameters are calibrated and a plug-flow model of the isothermal reactor is implemented and simulated in Aspen Plus. A reasonable agreement between experimental data and calibrated model is achieved, with deviations lower than 10% of the measured flow rates for each species in the product stream. CO2 conversion up to 26% and methanol yields up to 13% are obtained during the test campaign (test run #12). The model represents a valid tool for future research or engineering studies targeting the design and performance assessment of demo/full-scale CO2-to-methanol synthesis processes based on the Cu/Zn/Al/Zr catalyst introduced in this paper. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Strong oxidants have been reported to be required in the catalytic oxidation of CH4 to methanol in cyclic processes employing CuO-zeolites. Here, using Cu-exchanged zeolite omega (Cu-MAZ), it was demonstrated that O2 could be replaced by CO2, enabling the development of a new process. CuO-MAZ thermally treated in Ar, O2, or CO2 was investigated using in situ DRS-UV-Vis analysis and spectra calculated using density functional theory. The active species were characterized at different temperatures of reaction with CH4. The species of the type Zn-[CuxOy]n+ and main species Z-[CuOH-HOCu]2+-Z were formed on Cu-MAZ. After the reaction with CH4, the Cu+ formed from Zn-CuxOy could be reoxidized with CO2, while the Cu+ formed from Z-CuOH-HOCu-Z was only reoxidized with H2O, and not with CO2. After reoxidation with H2O, the activity of the material was fully restored by thermal treatment in O2 or CO2. The highest CH3OH yield was achieved using CO2. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
While impregnation approaches are attractive, scalable routes for preparing supported oxide catalysts, achieving competitive methanol productivities over impregnated ZnO/ZrO2 remains challenging as they underperform state-of-the art systems with isolated zinc sites. Herein, by targeting the optimal active site structure, ZnO/ZrO2 systems prepared by impregnation achieve stable methanol space–time yields of 0.73 gMeOH h−1 gcat −1 during CO2 and hybrid CO-CO2 hydrogenation at suitable conditions. Notably, controlling the catalyst formulation using 5 mol% Zn and a high surface area m-ZrO2 support fosters high zinc dispersion. In situ electron paramagnetic resonance and operando X-ray spectroscopy studies affirm the retention of isolated zinc species and facile generation of associated oxygen vacancies during the reaction. Analysis of pore structure and composition within the shaped bodies evidences abundant mesopores and a uniform zinc distribution, ensuring similar performance when translating from powder to technical forms. This work bridges fundamental understanding with practical demonstration of ZnO/ZrO2 systems. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Overuse of fossil fuel energy contributes to excessive CO2 emissions into the air, causing a range of environmental problems, which force people to change this situation. The proposal of the “carbon peak” and “carbon neutrality” strategies marked a new level of awareness of CO2 emissions. Utilizing the extensive and sustainable solar energy to transform CO2 into valuable chemicals is a promising avenue. In particular, the solar-assisted conversion of CO2 into methanol provides an effective method of storing carbon resources, thereby alleviating the environmental problems caused by CO2. In addition, the storage of solar energy in chemical energy could also alleviate the associated energy shortage issue. This review summarizes the latest achievements of catalysts in methanol synthesis from CO2 via photocatalysis, photothermal synergistic catalysis, and photoelectric synergistic catalysis. The advantages and shortages of each category of catalysts are pointed out and the future development perspectives are presented, hopefully facilitating the design and development of relevant photocatalysts. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Copper-based catalysts show potential advantages with respect to applications in CO2 photoreduction into valuable chemicals. However, there remain great challenges to reduce band gap energy and inhibit recombination of photogenerated electron-hole pairs. Herein, we report a metal-organic framework, Zn(II)/Cu(I, II)-BTC synthesized via facile one-pot solvothermal method. Asymmetric unsaturated tetrahedral copper coordination was verified by multiple characterizations including extended X-ray absorption fine structure and electron paramagnetic resonance analyses coupled with DFT calculations. Promoted separation and transfer of photogenerated electrons and largely inhibited recombination of electron-hole pairs contribute to a productive methanol yield of 4470 μmol·g−1·h−1, which is 107% higher than that over the parent Cu-BTC. In situ diffuse reflectance infrared Fourier transform spectroscopy measurement and DFT calculation were combined to elucidate the underlying mechanism. This study provides insights into effectively tuning separation and transfer of charge within copper-based photocatalysts and highlights the role of copper coordination in valence engineering. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Catalytic conversion of CO2 over zeolite-based catalysts has been deemed as a promising route and extensively investigated, while many issues remain intractable. Herein, for the first time, the novel AFX-type zeolite SAPO-56 was developed and impregnated with Cu nanoparticles to construct the bifunctional catalyst for further promoting CO2 transformation. By a systematically comparative analysis on the physicochemical properties and catalytic performance of different catalysts, the corresponding catalytic mechanism for a highly efficient methanol synthesis process from CO2 was comprehensively understood. The results showed that up to 16.4 % of CO2 can be converted into methanol with a relatively high selectivity of 80.9 % via 5% Cu/SAPO-56 catalysts at 280 °C though the formate activation pathway. This may be directly related to the specific Lewis acid sites (LAS) derived from the EFAl (extra framework aluminum) species located in the six-membered rings of SAPO-56 that endows it with distinguished adsorption capability of CO2. Furthermore, the copper nanoparticles that are highly dispersed on the surface or in the porous channel of SAPO-56 zeolite facilitate the ease of CO2 activation. Besides, the introduced hierarchical structure was considered to have played an indispensable role in improving methanol productivity. Meanwhile, all its own multiple superiorities also ensure Cu/SAPO-56 a remarkable stability, indicating the great potential for practical and industrial application. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
A potential measure to mitigate climate change and high energy consumption is the conversion of the abundant carbon dioxide (CO2) in industrial flue gas into value-added products. Herein, combined with the 300,000 tonnes of electrolytic manganese metal technical renovation project of Tianyuan Manganese Industry in Ningxia, the methanol production performed using 10,000 tonnes of CO2 annually is simulated. The hydrogen produced by alkaline hydro-electrolysis through solar and wind power generation is mixed with the CO2 purified in the manganese dioxide roasting workshop of the self-made manganese plant and fed into the methanol reactor with a Cu/Zn/Al/Zr catalyst. The methanol thus obtained is sold after separation and purification. The water at the bottom of the rectifying column is mixed with fresh water and circulated in the water electrolytic unit for hydrogen production. The design of the supporting photovoltaic (PV) power generation systems is simulated using TRNSYS18 software. Results show that the optimal reaction temperature, pressure and space velocity for methanol preparation using this system are 501 K, 50 bar and 5.9 m3/kgcat h, respectively. Simulation results indicate that the proposed methanol production process boasts a higher energy efficiency and process yield than the conventional process. Consequently, potential annual profits would increase by USD6.71 × 107 along with reduced greenhouse gas emissions. This study thus provides a novel approach for cogeneration of green methanol while reducing industrial waste gas emission. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Mo-Co-C-N catalysts are synthesized through ZIF-67 as precursor and they are high efficient catalysts for CO2 conversion to methanol. The highest STY of methanol of 3.3 mmol/gcat/h is obtained at 275 °C (XCO2 = 9.2%, SMeOH = 58.4%) for the optimized Mo-Co(2:1)-C-N(800) catalyst. Mo2C and Co6Mo6C2 are formed during the Mo-Co(2:1)-C-N catalyst preparation process, which catalyze both RWGS and methanol synthesis reaction. XPS and Temperature Programed studies show that much more oxygen vacancies are formed at higher calcination temperature (800 °C), which improve CO2 dissociated adsorption and hence increase methanol selectivity. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Atmospheric carbon dioxide is still a concern though few technologies have demonstrated capturing and utilization. CO2 utilization with H2 seems to be promising, but the necessity for new technology to enhance the economical sourcing of H2 is critical. In this regard, an attempt is made to realize H+ and OH− in-situ on the catalyst surface for the reaction with activated CO2 molecule using thermal methods. A multi-metallic catalyst has been studied to verify the feasibility of such a reaction path. The metal oxides such as Ni, Mn, Mo, Ru, etc., are known for disassociating vapor phase H2O molecule to H+ and OH−. It is also known for CO2 to form an activated metal complex with Ni, Ti, Co, etc. In this context, a combination of selected metal oxides could result in activated CO2 reacting with H+ or OH− to form hydrocarbons. The hydrothermal synthesis method was employed for the catalyst synthesis, consisting of Ru, Ni, and Mn oxides with TiO2 nanorod as substrate material. The catalyst analysis was done using characterization techniques like XRD, FESEM, EDAX, XPS, PSA, TGA, and FTIR. The influence of the heterogeneous metal-oxides catalyst on the reduction of carbon dioxide with steam is studied to determine the effective temperature of the reaction and products. It is observed that the conversion is effective for temperatures above 400 °C. It is found that the production rate of methanol is approximately 2 mmol/gcat /hr at 425 °C, indicating the feasibility of such reaction pathway by sourcing Hydrogen on the catalyst site. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
In this study, a series of Cu–Ce1-xZrxO2 (x = 0, 0.2, 0.5, 0.8, 1) catalysts were prepared by an eco-friendly and facile solid-phase grinding method. The effect of different Ce/Zr molar ratios on the performance of Cu–Ce1-xZrxO2 catalysts for CO2 hydrogenation to methanol was investigated. The results showed that the Cu–Ce0.5Zr0·5O2 catalyst had the best catalytic performance, with CO2 conversion of 15.2 % and methanol yield of 7.5 % at GHSV = 3600 mL/(gcat·h)); when GHSV was increased to 20,000 mL/(gcat·h), the space-time yield of methanol reached 270.8 gCH3OH/(kgcat·h). X-ray diffraction (XRD), scanning electron microscope (SEM), N2 adsorption-desorption, N2O chemisorption, X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction by H2 (H2-TPR), and temperature programmed desorption (H2-TPD, CO2-TPD) techniques were used to characterize the catalysts, and the higher reactivity of Cu–Ce0.5Zr0·5O2 can be attributed to more Cu0 species, defect oxygen and basic sites. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTs) results revealed that the hydrogenation of CO2 to methanol occurred through the formate intermediate pathway. This work proposed an eco-friendly and facile method for the preparation of high-performance Cu-based catalysts and the systematic study provided a deep insight for the development of high-performance Cu-based catalysts for methanol synthesis from CO2 hydrogenation. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
The hydrogenation of CO2 to methanol, which is restricted by water products, requires a selective removal of water from the reaction system. Here, we show that physically combining hydrophobic polydivinylbenzene with a copper catalyst supported by silica can increase methanol production and CO2 conversion. Mechanistic investigation reveals that the hydrophobic promoter could hinder the oxidation of copper surface by water, maintaining a small fraction of metallic copper species on the copper surface with abundant Cuδ+, resulting in high activity for the hydrogenation. Such a physically mixed catalyst survives the continuous test for 100 h owing to the thermal stability of the polydivinylbenzene promoter. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
The utilization of carbon dioxide is critical to realize the objective of "carbon peak and neutrality". Among various carbon dioxide exploitation approaches, catalytic hydrogenation of carbon dioxide is a significant method to selectively convert the CO2 into methanol and other valuable chemicals. Among these products, methanol is a crucial chemical feedstock that can be utilized as a platform molecule for the synthesis of chemicals and fuels as well as a fuel for internal combustion engines and fuel cells, causing particular interest. Nowadays, Catalytic hydrogenation of carbon dioxide into methanol has shifted its focus on the creation of low-cost, environmentally friendly, and efficient catalysts. Inspired of this, we have concluded the mechanism of catalytic hydrogenation of carbon dioxide, and reviewed the research progress of multiple heterogeneous catalysts with high catalytic application prospect, especially the supported catalysts. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
The viability of catalyzed CO2 conversion routes strongly depends on improving the catalytic performance and understanding of the process. Herein, we investigate the effect of Ca loading on PdZn/CeO2 catalysts prepared using the sol–gel chelatization method for CO2 hydrogenation to methanol. A remarkable improvement in catalyst performance was revealed with the optimum amount of Ca (0.5 wt%) in synergetic cooperation with the PdZn alloy (main active phase for the CO2 hydrogenation to methanol reaction), compared to the Ca-free counterpart. The following key performance indicators are attained at 230 °C, 20 bar, and 2400 h−1 GHSV for the optimized catalyst: 16 % CO2 conversion, > 93 % methanol selectivity, and ∼ 124 g/kgcat/h methanol space–time yield. The overall catalytic performance observed is attributed to the optimum Ce3+/Ce4+ ratio, Ca2+ promotion, surface area, pore volume, and basic sites, as revealed by various characterization techniques. Results shown here indicate that the presence of Ca in the vicinity of the PdZn active enhances basicity, creates oxygen vacancies, and phase may have improved the spill-over ability of H2, consequently favoring CO2 activation and methanol formation. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
This study aims a techno-economic analysis of a plant that produces methanol by hydrogenating carbon dioxide in the waste gas from an oil refinery using the electricity from floating photovoltaic power plant. First, carbon dioxide in the flue gas is captured in the carbon capture plant (CCP), and the hydrogen obtained from the seawater in the hydrogen plant (HP) with the help of photovoltaic energy is combined in the methanol plant (MPP) to produce methanol fuel. Using the Engineering Equation Solver (EES), a calculation was made of the amount of energy required and the number of solar panels or wind turbines that would be required to meet this demand, and then the environmental impact of the methanol plant was investigated. The Libyan Az-Zawiya oil refinery was considered for the case study due to its high solar potential, proximity to the sea and energy security. Systems' processes for CO2 emissions, heat integration, energy efficiency, and thermo-economic performance were all taken into consideration. Renewable energy, synthetic fuel, and the methanol plant showed efficiencies of 0.21%, 0.5872%, and 0.1626%, respectively, and at the optimum density of the electrolyzer, 2.2 kA/m2, the efficiency of the electrolyzer was 0.782%. According to this study, all output parameters increase with the increase in the flue gas in the process, showing that flue gas is the most important input parameter affecting the outputs. The total cost of the plant for 30 years of operation was found to be $11.350 billion, with a production capacity of over 43.360 million tons of methanol, which equates to $412.9 per ton and $0.4129 per kg. Environmentally, the rate of captured emissions was about 4890 tons per day, and the mitigation rate was approximately 4513 tons per day. According to the results, the current plant is competitive with other clean synthetic fuel production plants. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Converting CO2 into fuels and valuable chemicals such as methanol has been gaining significant attention as a favorable solution for reducing greenhouse gas emissions. Although Cu-ZnO-based catalysts are promising candidates for this reaction since methanol is selectively produced at the Cu-ZnO interface, Cu are not stable at elevated temperatures (500–600 K), leading to decrease in the surface areas of Cu and Cu-ZnO interface due to thermal aggregation of Cu. Furthermore, the generation of H2O as a by-product in the CO2 hydrogenation does not only accelerate the aggregation of Cu, but also inhibits an intermediate (formate species) formation for methanol. This paper reports the development of a novel catalyst, annotated as CuPS@S-1 by immobilizing Cu phyllosilicate (CuPS) as the Cu source within hydrophobic zeolite of Silicalite-1 particles (S-1). Cu@S-1 was obtained after the reduction CuPS@S-1 and the size of the Cu particles was approximately 2.4 nm. Cu@S-1 exhibited a higher CO2 hydrogenation activity and methanol selectivity than Cu/S-1 prepared by an impregnation method. To further improve the methanol production activity, ZnO was loaded onto Cu@S-1 to form a Cu-ZnO interface. ZnO/Cu@S-1 was obtained by the impregnation of CuPS@S-1 powder with an ethanol solution containing zinc acetate, followed by calcination and reduction. The obtained catalyst exhibited a better methanol production yield where the space–time yield for methanol based on the Cu weight exceeded 1200 mgmethanol gCu −1h−1. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
A facile approach is demonstrated for the fabrication of Cu-ZnO-based hybrid nanostructures for the catalytic CO2 conversion to methanol. The method combines colloid stabilization of Al2O3 nanoparticles (as support material) and controlled co-precipitation of Cu (active metal) and ZnO (promoter) onto the Al2O3 nanoparticles. Complementary approaches, including X-ray diffractometry, Brunauer-Emmett-Teller surface area analysis, N2O pulse chemisorption, CO2-based temperature-programmed desorption, transmission electron microscopy coupled with energy dispersive spectroscopy, inductively coupled plasma optical emission spectrometry and thermal gravimetric analysis are employed for the characterization of catalyst materials. The results show a successful synthesis of ultrafine Cu-ZnO nanocrystallites deposited on the Al2O3 nanoparticle clusters (Cu-ZnO@Al2O3). Hybridization with Al2O3 nanoparticles enhanced metal dispersion and number of basic sites of the Cu-ZnO-based nanocatalyst. Aminosilane-based surface functionalization on the Al2O3 nanoparticle increased metal surface area in the hybrid nanostructure. The CO2 conversion catalyzed by the synthesized Cu-ZnO@Al2O3 was shown to be proportional to active surface area of the hybrid nanostructure. An optimum selectivity of the synthesized catalyst was identified (≈47–49%) when the mass fraction of Al2O3 was (35–36) %, in correspondence to the highest moderate basicity of the synthesized hybrid nanostructures. The highest yield of methanol achieved 12989 ± 2007 µmolg−1 h−1 by the developed Cu-ZnO@Al2O3. Our work demonstrates a prototype study of fabricating high-performance hybrid nanocatalyst with the support of mechanistic understanding in material synthesis for the synergistic catalysis of CO2 hydrogenation to methanol. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Catalytic conversion of CO2 to methanol has attracted increasing interests as a promising strategy for reducing excessive CO2 emissions. However, the methanol selectivity drops rapidly with elevated temperature due to enhanced CO synthesis using conventional catalysts, which hiders its application. Herein, ZnO-ZrO2 solid solution catalysts (SSCs) were prepared with different methods and modified by adding extra metal, i.e., Al, Cr, Fe or Mg. As-prepared SSCs were characterized and tested in reaction. The results show that prepared ZnO-ZrO2 SSCs possess similar chemical compositions but different crystals, morphologies and pore systems, among which the C-ZZ synthesized by co-precipitation exhibits the optimal property. After doping, the basic crystal of tetragonal ZrO2 can be retained and ternary ZnO-ZrO2-MOx SSCs are successfully prepared. There come dramatic improvements in overall catalytic performance. Specifically, the 3Mg-C-ZZ SSC, at 3.0 MPa and GHSV of ˜2000 h−1, maintains a considerable methanol selectivity of 81.5 % even at 320 °C. Prepared catalysts present remarkable superiorities to conventional copper-based catalysts especially at high reaction temperatures, which endures them promising applications in coupling conversion of CO2 to valuable chemicals with the intermedia of methanol. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
This work compares 9 process routes that produce methanol from carbon dioxide using new and established thermochemical and electrochemical technologies. Net CO2 conversion is compared, and process efficiencies are benchmarked using side-by-side process models. New process routes using recently reported catalysts that enable methane pyrolysis (PY), and the dry reforming of methane (DMR) are modeled. Comparison is made with direct CO2 hydrogenation to methanol, the co-electrolysis of water and CO2 using solid oxide electrochemistry, and combinations of process technologies. Both electric heating and fuel switching to hydrogen are considered. Autothermal reforming of methane (ATR) is modeled as the conventional technology for reference. A new thermochemical approach in which CO2 reforming and methane pyrolysis reactions occur in separate reactors, with excess hydrogen produced and combusted for heat, (PY/DMR) was found to have the lowest levelized costs of CO2 mitigation varying from $50.4–53.9/t-CO2 using different electricity carbon intensities and levelized cost of methanol of $295.6/t. Methane pyrolysis offers the most flexible process solutions: it is nearly cost-competitive with reforming today ($295.6/t vs $277.3/t) using fuel switching and would emerge as the most economically viable process ($99.5/t) in future scenarios with very low electricity and natural gas costs and very high emissions penalties starting from 2030. Based on the emission factors from both electricity and natural gas across 195 countries around the world, 53 countries would result in net conversion of CO2 via pyrolysis today after heating, fugitive emissions, and energy use are taken into account. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
The active sites of copper-based catalysts and their impacts on activity and selectivity are first examined in this work, after which an overview of the regulation of the active sites and the pathways for CO2 hydrogenation reactions follows. The primary active sites influencing CO2 conversion and methanol yield and selectivity include Cu+/Cu0 species, Cu-oxide interfaces, Cu surface defect sites and M-Cu alloys. Strategies including additive control, carrier effect, and morphological modification can alter the kind and distribution of active sites. The main intermediates in the hydrogenation of CO2 to synthesize methanol are HCOO⁎ and COOH⁎. The main intermediates in the synthesis of methanol by CO2 hydrogenation are carboxyl species (COOH⁎) and formate species (HCOO⁎). The formate pathway can be further divided into the HCOO⁎ pathway and the r-HCOO⁎ pathway, depending on the intermediate involved. In the formate pathway, the hydrogenation of formate is the rate-determining step in the synthesis of methanol by CO2 hydrogenation. The carboxylate species pathway is subdivided into the RWGS+CO-Hydro pathway and the trans⁃COOH pathway. The rate-limiting steps for these two pathways are the formation of CO/HCO species and the dissociation of COHOH⁎ species, respectively. The review serves as the foundation for further developing copper base methanol catalysts that are extremely active, highly selective, and stable. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Mixing TiO2 with Mo2C has recently been proposed to improve the photocatalytic conversion of CO2 to methanol under visible light irradiation, although further efforts are still needed to enhance process performance. In this context, the use of p-type semiconductors (i.e., Cu2O) in co-doping strategies can enhance not only the redistribution of electric charges due to its narrowing bandgap, but also the selectivity of the reaction towards methanol. This work focuses on the development of a continuous visible light-driven CO2 photoconversion to methanol process in an optofluidic microreactor using Cu2O/Mo2C/TiO2 heterostructures. A significant improvement in process performance can be seen under visible light with the heterostructures containing 4 wt% of Cu2O. Superior methanol production rates (36.3 µmol∙g−1∙h−1) with an apparent quantum yield = 0.64% and a reaction selectivity = 0.93 are reached, in comparison with the results achieved at Cu2O-free Mo2C/TiO2 photocatalytic surfaces (11.8 µmol∙g−1∙h−1, 0.21% and 0.92, respectively). This can be adscribed to the role of Cu2O in the selectivity of the reaction towards methanol. The synergetic effect between Cu2O, Mo2C, and TiO2 in the heterostructures may also provoke a more efficient charge separation and transfer, while enhancing the visible light absorption properties of the material and its photocatalytic stability. The maximum methanol rate outperforms most of the values previously reported in slurry batch reactors and evidences the possibility of enhancing the continuous visible light-driven CO2-to-methanol photoconversion process with efficient metal co-doping approaches in optofluidic microreactors. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Biogas fuel has gained recognition as a highly suitable alternative to fossil fuels, attributed to its renewable nature and remarkable energy density. Biogas fuel utilization facilitates the integration of combined energy systems equipped with multi-generational structures, rendering them suitable for long-term planning and management. Hence, this study presents a unique approach to using biogas for multigeneration, exhibiting enhanced thermodynamic efficiencies and negative carbon dioxide emissions. To achieve the stated objective, an innovative system is devised that involves the utilization of a biogas separation unit in integration with several other components, including a LNG cold energy utilization unit, an ammonia Rankine cycle, a desalination unit, a Kalina cycle, a solid oxide electrolyzer cell, a biomethane combined cycle, and a methanol synthesis unit. The newly devised configuration is simulated through the Aspen HYSYS software and assessed from energy, exergy, environmental, and economic considerations. Based on the research findings, the suggested methodology exhibits energy and exergy efficiencies of 91% and 83%, correspondingly. Furthermore, the evaluation of the entire unit cost of the product and the levelized energy cost reveals values of 4.81 $/GJ and 0.033 $/kWh, respectively. The carbon dioxide emission intensity of the newly implemented process is calculated to be − 0.1041 kg/kWh. The economic aspects reveal a favorable net present value of 1470.6 M$ and a payback period of 5.29 years. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
In recent decades, climate change has become a major issue that needs to be addressed. Many efforts have been made on the reduction of CO2 emissions and its conversion in energy carriers and high value-added products such as methane, methanol, dimethyl-ether, and hydrocarbons. The present study focuses on the development of catalysts for hydrogenating CO2 to methanol, which is a useful chemical and an alternative liquid fuel. According to the literature, In2O3-based catalysts are particularly selective in the hydrogenation of CO2 to methanol, reducing the production of CO even at high space velocities compared to the more common ternary catalysts such as Cu/ZnO/Al2O3 or Cu/ZnO/ZrO2. Therefore, the effects of CeO2 and ZrO2 on In2O3-based catalysts were investigated in the present study. The InxCe100−x and the InxZr100−x mixed oxides catalysts were synthesized via gel-oxalate coprecipitation by varying the atomic ratios between the elements. Subsequently, they were analysed with several characterisation techniques to rationalise the catalytic performances that were obtained by testing the samples in a fixed bed reactor under different reaction conditions. The addition of different amounts Ce or Zr modified the structure and morphology of the samples and promoted the adsorption of CO2 from 1.8 mmolCO2⋅gcat −1 up to 10.6 mmolCO2⋅gcat −1. ZrO2 stabilises the structure and the results suggests that the greater specific activity (168 mgCH3OH⋅gIn2O3 −1⋅h−1 at 300 °C and 2.5 MPa of In40Zr60) could be ascribed to the electronic promotion of Zr. On the contrary, the addition of CeO2 did not reveal a beneficial effect on the activity. Concerning the stability, In2O3-ZrO2 binary oxides seemed to be affected mainly by sintering; whereas In2O3-CeO2 were affected by at least three deactivating phenomena: sintering, reduction of In2O3 to metallic indium and coking. Consequently, the deactivation rate of these binary oxides increased from 1.04 ⋅ 10−2 h−1 of the In100 to 4.13 ⋅ 10−2 h−1 of the In40Ce60. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Carbon dioxide hydrogenation to produce methanol has the potential to liberate humanity from its reliance on fossil fuels, while simultaneously reducing carbon dioxide and developing the economy. This paper focuses on the effect of catalyst type and the process conditions such as temperature, pressure, H2/CO2 feed ratio, and space velocity on CO2 conversion and CH3OH selectivity. The net generated CO in the reaction system results in the loss of CO2 and H2 to the purge gas, which reduces the utilization efficiency of carbon and hydrogen. The specially designed catalysts and processes with recycling can improve CO2 conversion and CH3OH selectivity, and the CO flow rate difference can be close to zero in the total recycling condition. Starting from these ideas, the two kinds of near-zero carbon emission processes with total recycling (respectively named total recycling process after flash separation and named total recycling process after stripping separation) are proposed. The utilization efficiency of carbon and hydrogen are similar in the two processes, but hot and cold utilities in the latter are 17.96% and 15.11% lower than in the former, respectively. Through the process integration between reaction heat and double-effect distillation, the energy consumption is further reduced in the total recycling process after stripping separation. The utilization efficiency of CO2 is 99.88% in the total recycling process after stripping separation with double-effect distillation of the light split/reverse configuration, and the proposed process just requires cold utility. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
With the accelerated process of industrial modernization, the continuous emission of CO2 seriously disrupts the natural carbon balance and contributes to global warming. To reverse this effect, CO2 photocatalytic reduction has received increasing attention. Among various value-added products converted from CO2, methanol has been regarded as an excellent fuel alternative and desired energy storage form. This review summarizes the different catalytic materials explored for CO2 photocatalytic conversion to methanol, and briefly describes the primary designing strategies for photocatalysts. Meanwhile, the fundamentals and mechanism of CO2 photocatalytic reduction to methanol are briefly discussed. And the development course of CO2 photocatalytic reduction to methanol has been attempted to organize. Furthermore, the paper tries to sort out the basic types of photocatalytic reaction systems with methanol as the product, and compares photocatalysis with other technologies that target CO2 conversion to methanol. Finally, this work ends with the conclusions of the CO2 photocatalytic reduction to methanol, and makes prospects for future development. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
The metal promoted In2O3 catalysts for CO2 hydrogenation to methanol have attracted wide attention because of their high activity with high methanol selectivity. However, there was still no experimental confirmation if copper could be a good promoter for In2O3. Herein, the Cu promoted In2O3 catalyst was prepared using a deposition-precipitation method. Such prepared Cu/In2O3 catalyst shows significantly higher CO2 conversion and space time yield (STY) of methanol, compared to the un-promoted In2O3 catalyst. The loading of Cu facilitates the activation of both H2 and CO2 with the interface between the Cu cluster and defective In2O3 as the active site. The Cu/In2O3 catalyst takes the CO hydrogenation pathway for methanol synthesis from CO2 hydrogenation. It exhibits a unique size effect on the CO adsorption. At temperatures below 250 °C, CO adsorption on Cu/In2O3 is stronger than that on In2O3, causing higher methanol selectivity. With increasing temperatures, the Cu catalyst aggregates, which leads to the formation of weak CO adsorption site and causes a decrease in the methanol selectivity. Compared with other metal promoted In2O3 catalysts, it can be concluded that the catalyst with stronger CO adsorption possesses higher methanol selectivity. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Hydrogenation of CO2 into methanol at low-temperature on Cu-based catalysts is of great significance, but remains challenging to enhance activity. In this paper, we report an inverse catalyst constructed with nano-ZrZnOx supported on Cu particles with outstanding methanol synthesis performance at 220 ℃, two times higher than that of commercial Cu/ZnO/Al2O3 catalysts under the same conditions. Detailed structure characterization and performance evaluation demonstrate that the ZrZnOx mixed oxide serves as the most active oxide-metal interface site for CO2 hydrogenation. The ZrZnOx/Cu inverse catalyst increases the weak and medium CO2 adsorption sites which are further demonstrated responsible to the methanol productivity. In situ DRIFTs studies reveal that the inverse interface accelerates the reduction of asymmetric formate intermediates and prevents the generation of CO. The combination of enhanced CO2 activation capability and accelerated hydrogenation rate of intermediates over the ZrZnOx/Cu inverse catalyst probably contribute to the remarkable methanol synthesis performance from CO2. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Replacing fossil fuels with renewable energy sources has a fundamental role in creating a sustainable and carbon-free economy. The catalytic hydrogenation of CO2 has great potential to reduce an enormous amount of CO2 and contribute to a green economy by converting CO2 into a variety of useful products. It is very important to develop new and highly efficient catalysts for the catalytic hydrogenation of CO2. Recently, the catalytic hydrogenation of CO2 has attracted an enormous amount of attention, which has been mainly focused on the development of efficient, selective, and stable catalysts. This review summarizes the current developments and improvements in the catalytic conversion of CO2 by H2 used toward the synthesis of CO, methanol, and hydrocarbons in terms of the catalyst performance, selectivity, and stability. The experimental procedures used for the three main pathways for the catalytic hydrogenation of CO2 (CO2 to CO via the reversible water gas shift reaction, CO2 to methanol synthesis, and CO2 to hydrocarbons via the Fischer–Tropsch reaction) using different catalysts are discussed. Furthermore, the industrial application of CO2 hydrogenation processes including their energy and economic analysis are also discussed. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Suppressing reverse water-gas-shift (RWGS) reaction is high desirable but challenging and underdeveloped for Cu/ZnO catalysts, particularly for commercial Cu/ZnO/Al2O3 catalysts. Different from the current methodologies to reduce RWGS reaction, we report a simply surface silylation method for efficiently minimizing RWGS reaction over a commercial Cu/ZnO/Al2O3 catalyst. This method suppresses STYCO (Space-time yield) from 97.4 to 0.7 gCO·kgcat −1·h−1, improving STYMeOH from 20.2 to 39.9 gMeOH·kgcat −1·h−1 and methanol selectivity from 15.1 to 92.9 mol%. The combination of characterization methods and density functional theory calculations provide insight into the suppressing mechanism of surface silylation on catalyst. A hydroxyl (on ZnO)-promoted RWGS reaction cycle is discovered, which can be efficiently inhibited by the consuming of hydroxyls via surface silyation. Our results provide a way to regulate RWGS reaction on Cu/ZnO-based catalysts and are expected to the further use of silylation strategy to tune the interconversion of CO and CO2 via RWGS/WGS reaction on hydrogenation catalysts. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Amine functionalized silica is an excellent sorbent for CO2 and when combined with Pd it has been demonstrated to selectively hydrogenate chemisorbed CO2 to methanol at a pressure of 1 bar H2. Up to 25% of the irreversibly captured CO2 could be converted by applying a dynamic switch between adsorption at 70 °C and conversion to methanol at 140 °C. The surface species, observed during sorption and reaction by IR spectroscopy, allowed to conclude that the reaction proceeds via formation of carbamates and their gradual reduction to methanol on sites located at the interface between the amine and Pd particles. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
In this study, a novel externally reflected photoreactor was compared with a solar photoreactor for photocatalytic CO2 conversion in liquid phase using proton-rich functionalized carbon nitride (f- C 3 N4) modified ZnV 2O6 nanosheets. Effects of operating parameters such as reaction medium and catalyst loading were investigated to maximize yield rates. The performance of photoreactor for CO2 photoconversion was higher in the presence of NaOH solution as a reducing agent than H 2 O and KHCO3 solution. ZnV2O6 modified with f-C 3 N4 (1:1) ratio registered the highest CH3OH yield. In an externally reflected photoreactor, the maximum yield rate of CH3OH over ZnV2O6/f-C 3 N4 (1:1) nanosheets was 4665.6 μ mole g-cat −1; 1.25 folds higher than solar photoreactor (3742.1 μ mole g-cat−1). The externally reflected photoreactor was found very efficient for photocatalytic CO2 conversion due to its higher light harvesting efficiency compared to the solar photoreactor. The increased yield rates in externally reflected photoreactor were because the reflector provides greater photon flux for dynamic CO2 reduction. Possible reaction mechanisms for photoconversion of CO2 over ZnV2O6/f-C 3 N4 S-scheme photocatalyst were proposed in order to understand the function of the reflector and the movement of electrons and holes. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
A continuous increase in the amount of greenhouse gases (GHGs) is causing serious threats to the environment and life on the earth, and CO2 is one of the major candidates. Reducing the excess CO2 by converting into industrial products could be beneficial for the environment and also boost up industrial growth. In particular, the conversion of CO2 into methanol is very beneficial as it is cheaper to produce from biomass, less inflammable, and advantageous to many industries. Application of various plants, algae, and microbial enzymes to recycle the CO2 and using these enzymes separately along with CO2-phillic materials and chemicals can be a sustainable solution to reduce the global carbon footprint. Materials such as MOFs, porphyrins, and nanomaterials are also used widely for CO2 absorption and conversion into methanol. Thus, a combination of enzymes and materials which convert the CO2 into methanol could energize the CO2 utilization. The CO2 to methanol conversion utilizes carbon better than the conventional syngas and the reaction yields fewer by-products. The methanol produced can further be utilized as a clean-burning fuel, in pharmaceuticals, automobiles and as a general solvent in various industries etc. This makes methanol an ideal fuel in comparison to the conventional petroleum-based ones and it is advantageous for a safer and cleaner environment. In this review article, various aspects of the circular economy with the present scenario of environmental crisis will also be considered for large-scale sustainable biorefinery of methanol production from atmospheric CO2. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Carbon dioxide as raw materials chemically transformed to valuable, renewable and high-energetic carbon feedstocks, especially if driven by renewable energy, is a desirable way to mitigate the depletion of fossil fuels and allow environmentally neutral use of carbon fuels. However, it remains more exploration of electrocatalysts with high activity and superior selectivity in converting CO2 to storable carbon-based liquid fuels, like methanol. Herein, we develop an in-situ sulfurizing strategy over the Bi-based metal-organic frameworks (Bi-BTC) and disperse stable and special Bi-S motif on subsequent S-doped carbon-framework (called BS@Cx ). Unlike the previous reports on Bi-based catalysts, as-prepared BS@Cx converted CO2 to methanol as major product at the whole applied potentials. Benefiting from the special Bi-S motif, it brought to the dramatic selectivity change of CO2 reduction production: dramatic decrease in HCOO− selectivity and increase in methanol selectivity. At −0.9 V vs RHE, maximum methanol faradaic efficiency (FE) and the selectivity of methanol arrived at 78.6% and 78.8%(Total-C FE was 95.5%), respectively. Some effective experiments involving of ECSA and charge transfer efficiency (Φ) certified that BS@Cx catalysts in the form of Bi-S motif exhibited higher intrinsic activity and selectivity, and overcame the energy barrier for methanol production. Coupled with PDOS of catalyst absorbed intermediates (OCHO* and CO*) and discussion of intermediates (COOH* and CH2O*), we bring forward a new possible pathway for catalyzing CO2 to methanol over BS@800. Further though microkinetic analysis with experimental Tafel slopes, we provided first-order understanding on the proposed reaction mechanisms, such as the rate-determining steps (RDS) and surface coverage (θ) of major reaction intermediates, and shed light on how rate-limiting steps can give rise to different Tafel slopes. This work may occur worthy insights into crystal structure engineering to achieve efficient electrocatalysts for selective CO2 conversion toward generation of valuable carbon-based chemicals. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
In this work, the reaction mechanism of dehydration reaction on Zn-doped ceria (CeO2) for the direct dimethyl carbonate (DMC) synthesis from CO2 and methanol is investigated from experimental and density functional theory (DFT) calculation perspectives. The dehydrating agent 2-cyanopyridine can greatly promote a shift in reaction equilibrium towards DMC by eliminating the undesired H2O. However, the dehydrating agent also causes the side reaction and reduces the DMC selectivity, especially under mild conditions (low CO2 pressure). Compared to the undoped CeO2-FD, the Zn-doped CeO2 significantly improves DMC selectivity from 82 % to 99 %, meanwhile showing high DMC yield with 434.3 mmol g−1 cat under 0.5 MPa CO2 pressure. The DFT calculation shows that the energy barrier of the side reaction on the Zn-doped CeO2 catalyst is much higher than that on CeO2. The charge distribution analysis demonstrates that more charge transfer creates enhanced Lewis bases, which hinders the side reactions. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Non-relevant |
In recent years, due to the substantial emission of CO2, global warming has become more severe, and there is an urgent need to develop technologies to reduce greenhouse gas CO2 emissions. Converting CO2 into higher alcohols is a promising process, as it not only produces valuable chemicals but also utilizes CO2 as feedstock. Currently, most reported catalytic approaches are based on direct hydrogenation of CO2 to synthesize higher alcohols. However, the synthesis of higher alcohols involves multiple steps, requiring catalysts with multiple functional sites and their synergistic interactions are crucial. Nevertheless, controlling catalysts at the nanoscale poses challenges, hindering the design of efficient multi-site catalysts. An alternative approach worth considering is to perform a tandem of multiple well-established catalytic reactions (e.g., methanol synthesis, CO2-Fischer-Tropsch-Synthesis, RWGS, syngas conversion, olefin hydration, etc.) to indirectly achieve the conversion of CO2 into higher alcohols, instead of direct CO2 hydrogenation. Therefore, in this review, these alternative strategies of higher alcohols synthesis are discussed, and their potential is evaluated. First, thermodynamic analysis, the selective adjustment strategies, and the current challenges faced for direct CO2 hydrogenation are introduced. Then, physical integration of multiple catalysts as a feasible strategy to endow the catalyst with multifunctional properties is discussed. Subsequently, several feasible routes of CO2 conversion into higher alcohols and the advanced catalysts employed for each pathway are summarized. Finally, merits and limitations of the different approaches are provided, emphasizing the great potential the tandem reaction strategy holds for the efficient synthesis of higher alcohols by CO2 conversion. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Non-relevant |
Conversion of CO2 into valuable fuel or chemical feedstock is important to sustainable technological development. Hydrogenation of CO2 to methanol, preferably under a relatively low temperature and moderate pressure, is attractive. In this study, a combined (CO2 + CO) hydrogenation process is proposed as an alternative two-stage route for methanol production. Cu-based hybrid catalysts supported on alumina nanoparticle clusters were developed for promoting methanol production. The results show an increase of ≈ 3.2 times in methanol space-time yield (STY MeOH) at 220 °C by incorporating CO to the CO2 hydrogenation process, and the maximum STY MeOH, 6.1 mmolgcat -1h-1, was achievable under a low-temperature (220 °C), moderate high-pressure operation (30 bar). The work demonstrates a rational design of hybrid nanostructured material to achieve superior catalytic performance in the combined (CO2 + CO) hydrogenation. The mechanistic understanding gives insights into the interfacial catalysis by Cu-ZnO hybrid nanostructured materials for methanol production. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
In this study, the direct synthesis conditions of dimethyl carbonate (DMC) from methanol and CO2 were controlled under the dual supercritical conditions, whose temperature was higher than the maximal critical temperature of CO2 and methanol (>239 ℃), and the partial pressure for each reactant was larger than its partial critical pressure (PCO2 > 7.4 MPa and Pmethanol > 8.1 MPa). A series of CeO2 catalysts with different morphologies including traditional nanorod, amorphous and flower structures were synthesized by hydrothermal method. The prepared catalysts were characterized by the BET, XRD, SEM, NH3/CO2-TPD, XPS, and H2-TPR, and the results indicated that flower CeO2 performed the largest acid-base sites and oxygen vacancies as expected, proving its superior physicochemical properties and catalytic activity. Moreover, the catalytic activity synthesis of DMC from CO2 and methanol was investigated, confirming that the flower CeO2 owned the highest catalytic performance, and the maximum yield of DMC was 3.11 mmol/gcat. under the reaction conditions (16 MPa, 250 °C, reaction time of 1 h without stirring). Importantly, the synthesis kinetic mechanism of DMC in dual supercritical systems was experimentally studied using the synthetic CeO2 catalysts, and the flower CeO2 catalyst possessed the lowest apparent activation energy of 45.9 kJ/mol, meanwhile, the initial reaction rate equation obtained from the experiment can be represented as: Rate = k [*] [CH3OH] [CO2]1/2, which was consistent with the reaction mechanism of Langmuir–Hinshelwood type. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
To address the CO2 accumulation in atmosphere, various initiatives have been proposed, among which CO2 capture and utilization (CCU) is regarded as an appealing strategy to reconcile carbon emission and resource utilization. Especially, integrated CO2 capture and utilization (ICCU), i.e. performing CO2 capture and in-situ conversion can circumvent the energy-intensive CO2 desorption step and thus facilitate establishing step- and energy-efficient process, rendering the conversion at mild conditions particularly at low pressure due to substantial activation upon CO2 uptake. However, CO2 capture and in-situ conversion is not the simple add-up of these two processes. Its successful implementation relies on the harmonization of CO2 capture reagents, substrates and the corresponding catalysts. By far, tremendous efforts have been made in this field and a plethora of CO2 capture reagents including inorganic bases, organic bases, ionic liquids and carbonaceous materials have been utilized to capture CO2 and the conversion protocols such as hydrogenation, cycloaddition, carboxylative cyclization etc. have been explored for these captured CO2. As a result, the valuable products containing methanol, methane, carbonates, carbamates, oxazolidinones, ureas, and quinazolinone have been obtained from CO2 and more importantly, the CO2 chemistry theory is also enriched via investigating the structure and reactivity of the captured CO2 in various reactions. In this review, we summarize the progress on CO2 capture and in-situ conversion based on the reaction types and corresponding CO2 absorbents. It’s hoped that this review can shed light on the design of CO2 capture and in-situ conversion and inspire the further development of this field. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Non-relevant |
Catalysts with the CeTi bimetallic modified dendritic mesoporous silica nanospheres (CTD) as supports, and the PdZn as active metal phase, PdZn/CTD catalysts with higher Pd metal dispersion and more oxygen vacancies were synthesized for efficient CO2 hydrogenation to methanol (MeOH). The modification of PdZn/CTD using CeTi metals can increase the dispersion of PdZn and improve the Ce3+/Ce4+ ratios. Higher active metal dispersion of PdZn/CTD catalyst is conducive to more H2 adsorption and to the expose of activation sites. Higher Ce3+/Ce4+ ratio of PdZn/CTD is beneficial to generate more oxygen vacancies, which can adsorb and activate CO2 molecules efficiently. The optimized PdZn/CTD catalysts exhibit superior CO2 conversion (33.6 %), MeOH selectivity (32.9 %), MeOH yield (11.1 %), TOF value (22.5 h−1), space–time yield (STY) (4.44 molMeOH kg-1 h−1) and 100 h long-term stability. Besides, through in-situ DRIFTS, HCOO* and CH3O* species are found to be the primary intermediates of the CO2 hydrogenation to MeOH reaction over the PdZn/CTD catalysts. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Relevant |
Various C1 feedstocks and lower hydrocarbons (C2-C4) can be produced from CO2 hydrogenation, which is an important way to utilize excess CO2 and provide alternative fuel options for dwindling fossil fuels. Herein, a novel two-bed catalytic system was developed to increase the yield of liquid range hydrocarbons, where the first catalytic bed was composed of In2O3-ZrO2 (13 wt. In %)/HZSM-5 and the second bed was a desilicated HZSM-5 placed downstream from the first bed. A maximum hydrocarbon selectivity was found to be about 86% with 7.2% CO2 conversion at 533 K, while conversion increased up to 19.3% with 71.2% hydrocarbon selectivity at 623 K while keeping the pressure at 4.0 MPa. The selectivity of longer liquid range hydrocarbons (C8-C12) was increased from 29.2% to 42.4% using the oligomerization process in which the produced lower olefins from the first bed were oligomerized to enhance the liquid range hydrocarbon over desilicated HZSM-5. Additionally, a comparative study was carried out to examine the effect of desilication over HZSM-5 having different silica-to-alumina ratios of 24 and 59. Moreover, detailed characterizations were carried out before and after the desilication of the HZSM-5 to correlate catalytic activities with physical and chemical properties of the catalysts. The results suggest that a two-bed catalytic system is a promising option to increase the yield of liquid range hydrocarbons from methanol-mediated CO2 hydrogenation while there was a negligible effect on CO2 conversion due to the second bed. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Non-relevant |
Next-generation bioprocesses of a future bio-based economy will rely on a flexible mix of readily available feedstocks. Renewable energy can be used to generate sustainable CO2-derived substrates. Metabolic engineering already enables the functional implementation of different pathways for the assimilation of C1 substrates in various microorganisms. In addition to feedstocks, the benchmark for all future bioprocesses will be sustainability, including the avoidance of CO2 emissions. Here we review recent advances in the utilization of C1-compounds from different perspectives, considering both strain and bioprocess engineering technologies. In particular, we evaluate methanol as a co-feed for enabling the CO2 emission-free production of acetyl-CoA-derived compounds. The possible metabolic strategies are analyzed using stoichiometric modeling combined with thermodynamic analysis and prospects for industrial-scale implementation are discussed. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Non-relevant |
The synthesis of dimethyl carbonate (DMC) from CO2 and methanol is an effective route of CO2 utilization. In this work, CeO2 nanorods prepared by hydrothermal synthesis using various drying methods were compared. Among them CeO2 prepared by freeze drying (CeO2-FD) had the highest and unprecedented catalytic effects, with DMC yield of 873 mmol g-1cat and methanol conversion of 51.6 % at 140 °C and 3.5 MPa for 4 h. All CeO2 nanorods catalysts have been extensively characterized and the results showed that CeO2-FD had the largest specific surface area (90.7 m2 g−1), pore volume, oxygen vacancy concentration (44.53%), and acid-base active site (189.4 vs 37.2 mmol g−1). The surface properties of CeO2 nanoparticles were greatly affected by the lower absolute pressure and the use of water as a template agent in freeze-drying. For the first time, the kinetic model of sequential reaction with a dehydrating agent was deduced by Langmuir-Hinshelwood mechanism. The activation energy barrier was 20 ± 3.3 kJ mol−1 using the Arrhenius formula. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Non-relevant |
Direct catalytic hydrogenation of CO2 to methanol is one of the most attractive ways to meet increasing fuel demand and reduce anthropogenic CO2 emission. An efficient catalyst is required for this highly complex structure-based reaction that simultaneously activates the CO2 molecule along with increased selectivity at feasible operating conditions. Application of machine learning models in catalysis research enables researchers to estimate and develop insights on the catalyst performances. This work focuses on development of machine learning (ML) models that include Multi Linear Regression, Least Absolute Shrinkage Selection Operator, Ridge Regression, Support Vector Regression, Gaussian Process Regression (GPR), Random Forest Regression, Gradient Boost Random Forest Regression (GBRT) and Artificial Neural Network (ANN) using published experimental data (698 datapoints) generated in a fixed bed reactor during the years 2010–2020. CO2 conversion and methanol selectivity were considered as catalytic activity performance indicators. Compared to other ML models, GBRT and ANN model predictions outperformed with R2 ∼ 0.95 and R2 ∼ 0.94 for CO2 conversion and with R2 ∼ 0.95 and R2 ∼ 0.95 for methanol selectivity respectively. Further, the input contributions using ANN models reveal that catalyst composition and calcination temperature are the significant inputs for CO2 conversion and methanol selectivity. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Non-relevant |
Designing catalysts that can efficiently convert CO2 into carbonates remains a challenge. Herein, the multifunctional CO2 affinity hyper-crosslinked ionic polymer was synthesized through self-condensation, quaternization, and ion exchange. The catalyst structure was characterized by FT-IR, TGA, NMR, XPS, and electron microscope spectra. The catalysts have a porous morphology, exhibiting a specific area of 542.2 m2/g and a CO2 adsorption capacity of 0.042 g/g. The CO2 cycloaddition with epichlorohydrin (ECH) can reach a yield of 93 % under metal- and solvent-free conditions. Meanwhile, the transesterification yield of dimethyl carbonate (DMC) between propylene carbonate (PC) and methanol was 62 % under ambient conditions and 83 % at 60 °C. Besides, the catalyst exhibited expansion of up to 16 substrates and no significant loss of activity after 6 cycles. Furthermore, the mechanism was evidenced by the combination of experimental studies and DFT-based calculations, revealing a synergistic effect between the active groups of the two reactions. This work emphasized the pathway that can simultaneously promote the formation of carbonates by both CO2 cycloaddition and transesterification under mild conditions. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Non-relevant |
The direct synthesis of dimethyl carbonate (DMC) from CO2 and methanol is a kind of highly-attractive route for CO2 conversion to high value-added chemicals. However, a key core problem is how to more effectively activate CO2. Here, we adopt simple template-free hydrothermal method to prepare CeO2 nanorods with oxygen vacancies and introduce light energy into the thermal catalysis system for promoting low-pressure photothermalcatalytic CO2 with methanol direct conversion to DMC. The SEM, HRTEM, XRD, XPS, N2 adsorption-desorption isotherm, CO2-TPD, EPR, Raman, photoluminescence spectra and UV-Vis-IR DRS characterizations are carried out to analyze the microscopical properties including the crystal phases, chemical states, structural features, optical properties for building up the intrinsic relationship with macroscopic performance. Our findings reveal that oxygen vacancies can not only act as photo-produced charge trapping center to prevent the recombination of photoinduced electrons and holes, but also promote CO2 adsorption and activation abilities through Lewis acid-base interaction. Finally, the detailed action mechanism for photothermalcatalytic CO2 conversion with methanol to DMC is proposed. This work should provide new ideas and insights for achieving the CO2 conversion into high value-added long-chain chemicals. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Non-relevant |
Dimensional matched ultrathin BiVO4/Ti3C2Tx MXene 2D/2D heterosystem is developed via a facile electrostatic self-assembly process. The composite shows an increased CO2 uptake capacity than that of the bare BiVO4 nanosheets. Besides, the well collaborated 2D/2D heterogeneous structure efficiently promotes the photoexcited charge transfer and separation. As a result, the photocatalytic CH3OH production rate of the BiVO4/Ti3C2Tx hydrid can reach 20.13 μmol g−1h−1, which is 4.1 times of the pristine BiVO4. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Non-relevant |
The integration of chemical absorption of CO2 and in situ transformation to highly valuable chemicals is a promising process as an alternative toward fossil fuels. Here, three imidazolium ionic liquids (ILs), 1-butyl-3-methylimidazolium acetate, 1-butyl-3-methylimidazolium 1,2,4-triazole ([Bmim][Tz]), and 1-butyl-2,3-dimethylimidazolium 1,2,4-triazole were synthesized to absorb and activate CO2 by the formation of CO2-adducts, which can be in situ converted into dialkyl carbonates with alcohols (ROH, R = CH3, C2H5, and C4H9) in solvent diiodomethane under ambient temperature and pressure. The results show [Bmim][Tz] exhibits the best CO2 absorption capacity and dimethyl carbonates (DMC) yield, where CO2 capacity is up to 0.216 gCO2/gIL and DMC yield (based on methanol) is as high as 20.2 %. The structures of imidazolium ILs have significant effects on the absorption of CO2 and subsequent transformation process. Fourier transform infrared and carbon nuclear magnetic resonance spectroscopies demonstrate ILs structures influence binding sites for CO2 absorption, which can combine with CO2 to form CO2-adducts, zwitterion [Bmim-CO2], and [Tz-CO2]−. Furthermore, density functional theory calculations verify the structure effects (binding sites and steric hindrance) of ILs on the activation of CO2 and methanol, through the elongated CO bond lengths of CO2-adducts and O-H bond lengths of methanol in IL-methanol complexes, respectively, leading to different DMC yields. The integrated process is promising for the energy-efficient capture and utilization of CO2 under ambient conditions. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Non-relevant |
This study reports the electrochemical synthesis, antimicrobial and catalytic activity of copper-arabinoxylan nanocomposite. The synthesis was achieved without use of any hazardous reducing and stabilizing agent. The spherical copper nanoparticles (size approx. 40 nm) dispersed in the arabinoxylan matrix as they formed and got stabilized. In the absence of arabinoxylan the particles rapidly converted to copper oxide suggesting a high stability for the composite. Electrolysis was carried out with copper plate as the sacrificial anode, carbon rod as the cathode and sodium nitrate (1.00 % in 1 % arabinoxylan suspension) as an electrolyte. The copper nanoparticles dispersed in arabinoxylan were characterized by surface plasmon resonance spectroscopy, X-ray diffraction, electron microscopy and zeta potential measurements. The synthesized composite exhibited good antimicrobial activity against P. aeruginosa, Staph. aureus and E. coli and a catalytic activity in conversion of CO2 to methanol. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Non-relevant |
In this paper, we report photoelectrochemical (PEC) conversion of carbon dioxide (CO2) using photocathodes based on Cu2O nanowires (NWs) overcoated with Cu+-incorporated crystalline TiO2 (TiO2 Cu+) shell. Cu2O NW photocathodes show remanent photocurrent of 5.3% after 30min of PEC reduction of CO2. After coating Cu2O with TiO2 Cu+ overlayer, the remanent photocurrent is 27.6%, which is an increase by 5.2 fold. The charge transfer resistance of Cu2O/TiO2 Cu+ is 0.423kΩ/cm2, whereas Cu2O photocathode shows resistivity of 0.781kΩ/cm2 under irradiation. Mott–Schottky analysis reveals that Cu+ species embedded in TiO2 layer is responsible for enhanced adsorption of CO2 on TiO2 surface, as evidenced by the decrease of capacitance in the Helmholtz layer. On account of these electrochemical and electronic effects by the Cu+ species, the Faradaic efficiency (FE) of photocathodes reaches as high as 56.5% when TiO2 Cu+ is added to Cu2O, showing drastic increase from 23.6% by bare Cu2O photocathodes. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Non-relevant |
The dramatic increase in atmospheric CO2 concentrations has attracted people’s attention, and many strategies have been developed to convert CO2 into high-value chemicals. Metal-organic frameworks (MOFs), as a class of versatile materials, can be used in the CO2 capture and conversion because of their unique porosity, large specific surface area, rich pore structure, multiple active centers, good stability and recyclability. Various functional nanomaterials have been designed and synthesized based on metal organic framework (MOF) of crystalline porous materials to meet these challenges. Herein, in this review, the latest processes of MOFs in field the of CO2 hydrogenation to carbon monoxide, methane, formic acid, methanol and olefins are summarized, and the synthesis methods of catalysts based on MOFs and the reasons for their high catalytic activity are analyzed. Besides, a brief introduction to improve the catalytic activity of the new MOF material and explore the feasible strategies for CO2 conversion are advised. Finally, the paper discusses the main challenges and opportunities of MOF-type catalysts in CO2 chemical conversion, and presents a brief outlook on further developments in this research area. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Non-relevant |
In this work, a techno-economic analysis on a novel plant configuration achieving the combined production of ammonia and methanol through chemical looping has been carried out. The innovative process presents advantages in terms of reduced dependency on market price fluctuations, thanks to the combined production of two chemicals, and optimal utilization of the chemical looping gases. The chemical looping plant is fed with recycled high density polyethylene to enhance the carbon circularity of the process. In this case, part of the captured CO2 is employed for methanol production along with hydrogen from chemical looping, while hydrogen from electrolysis is used for ammonia production by reaction with nitrogen from the air reactor. Renewable electric energy supply ensures a carbon free power to fuel conversion. Several sensitivity analyses were carried out to assess the optimum process parameters combination, i.e. fuel flow rate, steam flow rate, oxygen carrier inlet temperature. The final production rate is divided between 174 kg/h of methanol and 910 kg/h of ammonia. An economic analysis was then carried out. A capital cost of 27 M€ and an operating cost of 3 M€/y were computed. Sensitivity analyses on the impact of the electricity input cost, the electrolytic oxygen selling price, the electrolyser capital cost and the internal rate of return were carried out. The electricity demand was discovered to impact for the 68% of the total operating costs. For an electricity cost of 0.03 €/kWh, oxygen selling price of 0.07 €/kgO2 and internal rate of return of 8%, a final products cost of 0.76 €/kg was then determined. The process achieves specific CO2 emissions of 0.017 kgCO2/kgprd, which is significantly lower than the traditional processes (0.24 kgCO2/kgCH3OH and 1.66 kgCO2/kgNH3), and an energy intensity of 36 GJ/tprd. The final selling price of the products is still not competitive with the traditional processes but is comparable with ammonia production from electrolysis and air separation and methanol production from electrolysis and direct air capture. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Non-relevant |
With conventional methanol reactor designs for CO2-based methanol synthesis, there is the risk of rapid catalyst deactivation with commercial Cu/ZnO/Al2O3 catalysts at high water partial pressures, related to the use of CO2 as carbon feed. As catalyst reactivity and exothermicity are influenced by the switch to a CO2-rich feed, also heat integration options are affected. A new reactor/process design, the Infinity Reactor, is proposed to both improve catalyst lifetime and reduce catalyst usage. The Infinity Reactor is a shell and tube type of reactor, with catalyst on both sides, utilising the difference in temperature between the inlet and outlet of the reactor to operate as a quasi-gas-cooled reactor. The gas loops over both sides of the reactor, with intermediate cooling and condensation. This modelling study shows around 35% savings in catalyst volume in comparison with adiabatic operation.
| Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Non-relevant |
In tandem catalysts, not only good synergy between the two active components is required, but also the precise control of the spatial distribution between the two active components of metal oxides and zeolite is crucial for the migration and conversion of reaction intermediates in the direct conversion of CO2 to hydrocarbons. The correlation between the metal and the acidic site of zeolite has traditionally been simplified as “the closer, the better”. However, it should be noted that this principle only holds true for a portion of tandem catalysts. Therefore, this paper studied the effect of different crystalline In2O3 (cubic phase, hexagonal phase, and mixed cubic/hexagonal phase) and sheet HZSM-5 zeolite tandem catalysts on the activity of CO2 hydrogenation reaction under different spatial distribution. The generalized gradient approximation (GGA) of density functional theory (DFT) were used to simulate the adsorption energy of CO2 by oxygen vacancy on c-In2O3(111) and h-In2O3(104) planes, it was found that Ov1 on c-In2O3(111) and Ov4 on h-In2O3(104) had the strongest adsorption energy for CO2. In addition, it has been observed that the proximity of the two active components (e.g., during mortar mixing) results in decreased catalytic performance. This is due to the migration of metal In, which neutralizes the acid sites of zeolites and leads to inefficient conversion of methanol reaction intermediates to aromatics. As a result, CO2 conversion and aromatic selectivity are decreased. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Non-relevant |
The rising CO2 concentration in the atmosphere calls for not only the decarbonization of our lifestyle but also the removal of CO2 to meet the sustainable development goals. In this work, a comprehensive techno-economic comparison based on systematic process design of CO2 capture technologies from the air is performed. Biomass and direct air capture (DAC) are considered as well as the further utilization of CO2. A common final product, methanol, is selected for easier comparison. Six different biomasses are considered, including energy crops, forests, and agriculture. Four biomass gasification routes are evaluated to produce methanol. Two direct air capture technologies are followed by CO2 hydrogenation. Hydrogen is produced by splitting water using solar and/or wind energy. The current status of the technologies gives biomass an advantage as carbon capture technology with production and investment costs ten times lower, due to the high price of the renewable energy collection for the operation of the fans. However, the area required for growing biomass, except in the case of residues, and the total amount of water consumed, favors the engineered alternative, DAC. The investment and production costs depend on the location and the technology development. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Non-relevant |
Carbon dioxide (CO2) emissions from a variety of sources, such as transportation, fossil fuel burning, and cement manufacturing facilities, are widely regarded to be the root cause of global warming. The rising CO2 levels call for immediate improvements in CO2 capture, extraction, and utilization technology. Methods for capturing and converting CO2 into useful products have included the use of microbial enzymes, nonporous materials, metal-organic frameworks (MOFs), chemicals, and hybrid membranes. However, these methods possess limitations that make the scale up and commercialization challenging. Scientists are concentrating on maximizing CO2 utilization by incorporating CO2-philic components into enzyme-chemical-material combinations, due to the high solubility of CO2. Here, the focus is on the chemistry of CO2-philic materials, enzymes and biomolecules engaged in CO2 conversion, and the hybrid micro-reactors that contain material and enzymes integrating together to convert the CO2 into value-added products (organic acids, bioelectricity, carbonates, carbamates, methane, methanol, etc.). The difficulties and obstacles inherent in creating and sustaining such systems have also been highlighted. | Classify the abstract into relevant or non-relevant based on the following defination: Relevant: The abstract contains information about the reactants, products, and methodology related to methanol synthesis. Non-relevant: The abstract does not contain information about one or more of the following: reactants, products, or methodology related to methanol synthesis. | Non-relevant |
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