Synthesis of γ-Valerolactone by Hydrogenation of Biomass-derived Levulinic Acid over Ru/C Catalyst

Ru/C catalyst was used in hydrogenation of levulinic acid to produce γ-valerolactone. The conversion rate and the selectivity of levulinic acid to γ-valerolactone with Ru/C as catalyst were higher than those with Pd/C, Raney nickel, and Urushibara nickel. The optimum preparation conditions of γ-valerolactone by hydrogenation of levulinic acid catalyzed by Ru/C were as follows: temperature at 130 °C, hydrogen pressure at 1.2 MPa, dosage of catalyst at 5.0% (based on the mass fraction of levulinic acid), the solvent being methanol, and a reaction time of 160 min. The conversion rate of levulinic acid to γ-valerolactone was found to be 92%, and the selectivity of γ-valerolactone was 99%. The surface structure variations of the fresh and used catalysts were characterized by XRD and XPS. Furthermore, the reaction pathway for the hydrogenation of levulinic acid was proposed.