Heterogeneous Catalytic Hydrogenation of Levulinic Acid to g Valerolactone with Formic Acid as Internal Hydrogen Source: Key Issues and Their Effects.
As one of the most promising biomass based platform molecules, g valerolactone (GVL) can be synthesized from a variety of lignocellulosic feed stocks via different hydrogen supply pathways. Among these transformation routes, hydrogenation of levulinic acid (LA) to GVL using Formic acid (FA) as the internal hydrogen source is regarded as a critical path for the sustainable development of renewable energy systems. Although a large number of studies on the synthesis of GVL have been reported, the FA/LA catalytic system has not been thoroughly interpreted as it should be. Here in, core concerns are focused on key issues and their effects in this FA/LA catalytic system. The catalytic mechanism, together with competitive ad sorption behaviour between FA and LA on heterogeneous catalysts, was presented. Effects of active metal species and catalyst supports on the overall catalytic performance were summarized. Influences of key condition parameters, including the time and temperature, FA/LA molar ratios as well as the aqueous solvent, were discussed. In particular, impacts and improvements of coke deposition and metal leaching, which could greatly affect the catalyst stability, were analysed in detail. Additionally, several feasible suggestions for the enhancement of the catalytic efficiency and stability were also proposed.
ChemSusChem