Hydrogenation of Levulinic Acid over Biomass-based Ru/NC Catalyst

The conversion of levulinic acid to γ-valerolactone is one of the most important reactions from biomass platform molecule to value-added chemicals. Ru-based catalysts have shown high activity and selectivity in previous studies but always required complex synthetic method or harsh reaction conditions. In this work, biomass-derived chitosan was used to prepare nitrogen doped carbon. After the loading of Ru, the Ru/NC (NC: nitrogen-doped carbon) catalyst was employed in the solvent-free hydrogenation of levulinic acid under ambient hydrogen pressure at 50−80 °C to reach full conversion. The calcination temperature was optimized to get Ru/NC-800 catalyst with high intrinsic turnover frequency of 358 h⁻¹. The apparent activation energy was studied by kinetic experiments. More significantly, the catalyst was small-scaled tested for 36 h in a fix-bed reactor with 620 g/day productivity of γ-valerolactone. The catalyst can be easily synthesized and have high activity and stability, underscoring the potential of future commercial production of γ-valerolactone from levulinic acid.