Selective hydrogenation of levulinic acid to γ-valerolactone on Ni-based catalysts

Abstract

In this work, Ni-based catalysts were prepared using the impregnation method. Ni/Al2O3 showed good performance with a γ‐valerolactone (GVL) yield of 99.2% from hydrogenation of levulinic acid (LA). Among the tested bimetallic catalysts, the NiCo catalyst showed better performance than NiMn, NiMo, and NiCu catalysts for the hydrogenation of LA to GVL. Catalysts with different Ni/Co ratio were synthesized, and 15%Ni-15%Co/Al2O3 shows the best performance with a GVL yield of 99.5%. The textural and chemical characteristics of the NiCo/Al2O3 were determined by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and H2 temperature-programmed reduction (H2-TPD). This study shows that the incorporation of the Ni and Co metals formed a Ni-Co alloy, which significantly increased the activity than other Ni-based bimetallic catalysts and led to a milder condition for hydrogenation of LA to GVL. The test of reuse potential of 15%Ni-15%Co/Al2O3 exhibited good stability up to 5 cycles without obvious deactivation.