Novel nano-semiconductor film layer supported nano-Pd Complex Nanostructured Catalyst Pd/Ⓕ-MeOx/AC for High Efficient Selective Hydrogenation of Phenol to Cyclohexanone
Supported metal as a type of heterogeneous catalysts are the most widely used in industrial processes. High dispersion of the metal particles of supported catalyst is a key factor in determining the performance of such catalysts. Here we report a novel catalyst Pd/Ⓕ-MeOx/AC with complex nanostructured, Pd nanoparticles supported on the platelike nano-semiconductor film/activated carbon, prepared by the photocatalytic reduction method, which exhibited high efficient catalytic performance for selective hydrogenation of phenol to cyclohexanone. Conversion of phenol achieved up to more than 99% with a lower mole ratio (0.5%) of active components Pd and phenol within 2 h at 70 °C. The synergistic effect of metal nanoparticles and nano-semiconductors support layer and the greatly increasing of contact interface of nano-metal-semiconductors may be responsible for the high efficiency. This work provides a clear demonstration that complex nanostructured catalysts with nano-metal and nano-semiconductor film layer supported on high specific surface AC can yield enhanced catalytic activity and can afford promising approach for developing new supported catalyst.
A mesoporous hollow silica sphere (MHSS): Synthesis through a facile emulsion approach and application of support for high performance Pd/MHSS catalyst for phenol hydrogenation
Abstract A facile route to synthesize mesoporous hollow silica sphere (MHSS) via TEOS emulsion droplet assisted with dodecyl amine (DDA) was developed in this work. The particle sizes of MHSS are around 400–600 nm and the BET surface area is high up to 951 m 2  g −1 and with a uniform pores diameter of 3.7 nm in the silica wall. Thermogravimetric analysis found that the MHSS displayed good thermal stability. The effects of solvent, TEOS amount and DDA addition on the property of MHSS were also investigated. It was found that the solvent composition and the required DDA concentration are the key factors for the determination of hollow structure. Pd loaded MHSS catalyst showed high catalytic activity and good recycling ability in the liquid phenol hydrogenation under mild reaction conditions.
Synthesis, characterization and liquid phase oxidation of cyclohexanol using tert-butylhydroperoxide over host (zeolite-Y)/guest (copper(II) complexes of 12- and 13-membered diaza dioxa Schiff-base macrocyclic ligand) nanocomposite materials (HGNM)
Abstract Nanocavity microreactor containing 12- and 13-membered diaza dioxa Schiff-base copper(II) complexes have been prepared by the one-pot template synthesis of (1,8-diamino-3,6-dioxaoctane)copper(II) with bifunctional diketone within the pores of zeolite-Y. The copper(II) complexes were entrapped in the supercage of Y-zeolite by a two-step process in the liquid phase: (i) inclusion of a copper(II) precursor complex, [Cu(1,8-diamino-3,6-dioxaoctane)] 2+ -NaY and (ii) template condensation of the copper(II) precursor complex with the bifunctional diketone. Encapsulated copper(II) complex is catalytically very efficient as compared to other neat complexes for oxidation of cyclohexanol with tert -butylhydroperoxide (TBHP) as oxidant and is stable to be recycled without much deterioration.