Bimetallic NiCu Alloy Catalysts for Hydrogenation\nof Levulinic Acid

Abstract

Upgrading of the biomass-derived\nlevulinic acid (LA) with the activation\nof carbonyl functional groups is a pivotal reaction in converting\nbiomass into high-value-added products. Herein, we reported a modified\nstrategy to synthesize highly dispersed noble-metal-free bimetallic\nNiCu alloy nanoparticles (NPs) from metal–organic frameworks\nfor the selective hydrogenation of LA, in which the ligand effect\nbetween Ni and Cu plays a crucial role under relatively mild conditions.\nAmong the tested catalysts, the catalyst with a Ni/Cu ratio of 1:2\npresented the best catalytic performance in comparison with the homometallic\nNi/Cu and bimetallic catalysts with different ratios; an outstanding\nyield of 93.9% was obtained for γ-valerolactone (GVL). Both\nexperimental studies and characterization analyses verified that the\nligand effect is responsible for the excellent catalytic performance.\nA possible reaction pathway for the samples in the LA hydrogenation\nprocess is proposed; after dissociation of adsorbed H₂ on\nthe NiCu alloy surface, reactant LA is adsorbed and activated by NPs\nwith the formation of intermediate, and through a self-condensation\nreaction to form products. The straightforward synthesis, superior\nperformance, and high stability make these noble-metal-free bimetallic\nNiCu nanoparticles very attractive for the transformation of various\nbiomass-derived sources into valuable products.