Switching production of γ-valerolactone and 1,4-pentanediol from ethyl levulinate via tailoring alkaline sites of CuMg catalyst and hydrogen solubility in reaction medium

Abstract

Abstract γ-Valerolactone (GVL) and 1,4-pentanediol (1,4-PeD) are the biomass-derived chemicals with the tunable functionalities, serving as the platform for synthesis other value-added product. In this study, we have demonstrated that the production of GVL and 1,4-PeD from ethyl levulinate (EL), a product from alcoholysis of biomass, could be switched flexibly via tailoring the copper content and abundance of the basic sites in the CuMg catalyst and the reaction medium, achieving the yields up to 99% and 97.7% under optimal experimental condition. The production of GVL was favored over the CuMg catalyst with the high Cu content, while the abundant basic sites in the CuMg catalyst were the key for further opening of the furan ring in GVL to form 1,4-PeD. Furthermore, the alcohol solvent especially isopropanol with the higher hydrogen solubility also facilitated the production of 1,4-PeD. Water as the reaction medium induced significant sintering of Cu in CuMg catalyst, while the alcohol solvent could effectively suppress the aggregation of copper species, maintaining the high catalytic stability.