Highly efficient catalytic transfer hydrogenation of 5‐hydroxymethylfurfural to 2,5‐dimethylfuran over CuxZnAl catalysts

Abstract

AbstractTransformation of biomass‐based feedstocks to fuels or valuable chemicals is of great importance to reduce our reliance on fossil resources. In this work, 2,5‐dimethylfuran (DMF) production through catalytic transfer hydrogenation of 5‐hydroxymethylfurfural (5‐HMF) in liquid phase was investigated over ternary CuxZnAl catalysts using isopropanol as hydrogen donor. The excellent catalytic performance of the CuxZnAl catalysts can be attributed to the well‐dispersed Cu species with optimal proportions of Cu2+, Cu0, and Cu+. The synergistic effect of Cu0 and Cu+ is proposed to be responsible for the high hydrogenation/hydrogenolysis activity of 5‐HMF. Using the Cu2ZnAl‐600‐300 catalyst (calcinated at 600°C and reduced at 300°C), 91.7% DMF yield was achieved under 180°C within 4 h. High‐resolution transmission electron microscopy, energy‐dispersive X‐ray spectroscopy, X‐ray diffraction, H2 temperature‐programmed reduction, NH3 temperature‐programmed desorption, and X‐ray photoelectron spectroscopy were performed to investigate the structure–performance relationship and the reasons for the high catalytic performance of Cu2ZnAl‐600‐300.