Hybrid Nano‐Structured Pd Catalyst for Selective Hydrogenation of Phenol and the Insights of Deactivation Mechanism

Abstract

A catalyst composed of La2O3/AC and Pd nanoparticles is constructed for precise synthesis of cyclohexanone from phenol hydrogenation with high conversion (>99 %) and selectivity (>95 %). The special structure and the synergistic effect remarkably facilitate the high conversion of phenol. The stability test results of the used Pd/@‐La2O3/AC catalyst showed that the phenol conversion decreased from 100 % to 24.5 %. The deactivation reason for the used catalyst was the agglomeration of Pd nanoparticles and the adsorption of organics. Three treatment methods, heat treatment, ethanol wash, and water wash, were regenerated the catalytic activity of the used Pd/@‐La2O3/AC catalyst. The regenerated method of water wash solved the problem of organic matter blockage and residue to a certain extent, but still can not fully recover its high activity. This deactivation mechanism provides important guidance to develop high stable Pd‐based catalyst for the selective hydrogenation of phenol.