Hydrogenation of biomass-derived ethyl levulinate into γ-valerolactone by activated carbon supported bimetallic Ni and Fe catalysts

Abstract

Gamma-valerolactone (GVL) has been identified as a sustainable high-value platform molecular for the production of fuels and carbon-based chemicals. In this work, a series of activated carbon supported low-cost bimetallic Ni-Fe catalysts (Ni-Fe/AC) with different molar content of Fe species were prepared by using co-precipitation method for the liquid phase hydrogenation of ethyl levulinate (EL) to produce γ-valerolactone. The Ni-Fe0.5/AC exhibited the highest activity among the bimetallic or monometallic catalysts under mild reaction conditions (100°C, 4MPa H2, 6h) and achieved 99.3% conversion of EL and 99.0% yield of GVL. Under more mild conditions (60°C, 2MPa H2) and prolonging the reaction time to 24h, EL could be converted completely and the obtained GVL yield was more than 98%. The catalysts were characterized by various techniques including XRD, TEM, HRTEM, EDX, XPS, H2-TPR and NH3-TPD. Based on the structure and activity relationship study, the formation of highly dispersed Ni-Fe alloy structure and the co-presented FeOx nanoparticles could be responsible for the high catalytic hydrogenation activity.