Water-Promoted Hydrogenation of Levulinic Acid to γ-Valerolactone on Supported Ruthenium Catalyst

A highly efficient and green process for the hydrogenation of biomass-derived levulinic acid (LA) to -valerolactone (GVL) has been developed. GVL was obtained in a yield of 99.9mol% with a turnover frequency as high as 7676h(-1) in aqueous medium by using a Ru/TiO2 catalyst under mild reaction conditions (70 degrees C). The strong interaction between Ru and TiO2 facilitated both the dispersion of Ru nanoparticles and the stability of the catalyst. In addition, as solvent, water participated in the hydrogenation of LA, which was confirmed by an isotope- labeling experiment with D (D2O). Specifically, the H atom(s) in water took part in the hydrogenation of the CO group of LA, which promoted the catalytic activity and GVL yield remarkably.