La2O2CO3-Supported Ni Nanoparticles with Enhanced Metal–Support Interactions for Selective Hydrogenation

Abstract

Electronic metal–support interactions (EMSIs) of supported metal nanoparticle (NP) catalysts have significant impacts on catalytic performances. In this work, phase transition from the monoclinic phase with La–O₆ bonds to the hexagonal phase with La–O₈ bonds of La₂O₂CO₃ is induced by the presence of Ni, and the process of phase transition is characterized by XRD. The resulting La₂O₂CO₃-supported Ni NP catalyst shows an improved EMSI in comparison to the Ni/La₂O₂CO₃ catalyst prepared by a simple impregnation method. The enhanced EMSI effects are revealed by extensive characterizations such as XPS, H₂-TPR, and H₂-TPD. The EMSI effects create more Ni^δ+–O–La interfaces that are responsible for the enhanced reaction activity toward biomass upgrading of selective hydrogenation of levulinic acid to γ-valerolactone. This work provides insight into the use of phase transition to strengthen EMSI effects.