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

•Bimetallic Ni-Fe/AC catalysts with different Fe/Ni ratios are prepared.•Ni-Fe/AC catalysts are efficient for catalyzing EL to GVL under mild conditions.•The catalysts are characterized by XRD, TEM, HRTEM, EDX, XPS, H2-TPR and NH3-TPD.•Ni-Fe alloy and co-presented FeOx contribute to the high catalytic activity.•The Ni-Fe/AC catalysts can be easily separated due to their strong magnet.

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, 4 MPa H2, 6 h) and achieved 99.3% conversion of EL and 99.0% yield of GVL. Under more mild conditions (60 °C, 2 MPa H2) and prolonging the reaction time to 24 h, 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.

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