Effective production of γ-valerolactone from biomass-derived methyl levulinate over CuOx-CaCO3 catalyst

The production of γ-valerolactone (GVL) from lignocellulosic biomass has become a focus of research owing to its potential applications in fuels and chemicals. In this study, ( n )CuO x -CaCO 3 (where n is the molar ratio of Cu to Ca) compounds were prepared for the first time and shown to function as efficient bifunctional catalysts for the conversion of biomass-derived methyl levulinate (ML) into GVL, using methanol as the in-situ hydrogen source. Among the catalysts with varied Cu/Ca molar ratios, (3/2)CuO x -CaCO 3 provided the highest GVL yield of 95.6% from ML. The incorporation of CaCO 3 with CuO resulted in the formation of Cu + species in a CuO x -CaCO 3 catalyst, which greatly facilitated the hydrogenation of ML. Notably, CuO x -CaCO 3 also displayed excellent catalytic performance in the methanolysis products of cellulose, even in the presence of humins. Therefore, a facile two-step strategy for the production of GVL from cellulose could be developed over this robust and inexpensive catalyst, through the integration of cellulose methanolysis catalyzed by sulfuric acid, methanol reforming, and ML hydrogenation in methanol medium.