Aqueous phase hydrogenation of levulinic acid to γ-valerolactone on supported Ru catalysts prepared by microwave-assisted thermolytic method

γ-Valerolactone (GVL), as a sustainable platform chemical, were produced through an aqueous phase hydrogenation of biomass-derived levulinic acid (LA) in the presence of supported ruthenium catalysts, in which the catalysts were prepared by solvent-free microwave-assisted thermolytic method. The effects of catalyst support, reaction media, pressure, temperature and LA initial concentration were investigated to obtain the optimum conditions for high γ-valerolactone yield. 5% Ru/AC catalyst exhibits a more superior catalytic performance compared with Ru/CNT, Ru/FCNT, Ru/γ-Al₂O₃-MW and Ru/γ-Al₂O₃-IM at 100℃ and 2.0 MPa of 0.10 g/mL LA concentration in water solution. This superior performance is attributed to the higher dispersion of metallic Ru over coconut shell activated carbon. GVL can be produced with a good yield of > 99% under optimum conditions, and has the potential to provide a green, renewable platform for biotransformation.