Highly efficient hydrogenation of levulinic acid into 2-methyltetrahydrofuran over Ni–Cu/Al2O3–ZrO2 bifunctional catalysts

Abstract

Transformation of biomass or biomass-based feedstocks into fuels or valuable chemicals is of great importance for the sustainable development of our society. Mesoporous Al₂O₃–ZrO₂ with different Al : Zr molar ratios was prepared by the sol–gel method, and Cu–Ni/Al₂O₃–ZrO₂ catalysts were fabricated by the impregnation method. The catalytic performances of the bifunctional catalysts were studied in the selective hydrogenation of levulinic acid (LA) into 2-methyltetrahydrofuran (MTHF). It was demonstrated that both Cu : Ni and Al : Zr ratios affected the selectivity to MTHF significantly. The bimetallic catalysts Cu–Ni/Al₂O₃–ZrO₂ containing 10 wt% Ni and 10 wt% Cu gave 99.8% MTHF selectivity at full conversion of LA when the Al : Zr ratio was 9 : 1. The outstanding catalytic performance of the catalyst is related to the mesoporous structure, the acidic properties of the support and the synergistic effect between Cu and Ni. The catalyst could be reused five times without a considerable loss of catalytic activity and selectivity.