Tailoring the Phenol Adsorption on Pt@TiO2 to Improve Electrocatalytic Hydrogenation Performance via Metal-Support Interaction

Abstract

Electrocatalytic hydrogenation (ECH) of biomass-derived phenolic compounds emerges as a burgeoning avenue to upgrade lignocellulosic bio-oil to value-added chemicals, necessitating the exploration of active and selective ECH electrocatalysts. Up to now the mostly explored catalysts applied to ECH are mainly based on Pt, yet the faradaic efficiency (FE) of Pt-catalyzed ECH of phenolic compounds remains relatively low, owing to the competitive hydrogen evolution reaction (HER). Herein, highly dispersed Pt nanoparticles supported on rutile TiO₂ nanowires substrate (Pt@TiO₂) is elaborately constructed to regulate the electronic structure of active Pt species through metal-support interaction. The oxygen vacancy-rich TiO₂ nanowire is conducive to the anchoring of Pt, thus preventing the aggregation of small-sized Pt nanoparticles, while the interaction between Pt nanoparticles and TiO₂ support stimulates the electrons transfer from TiO₂ to Pt, enhances the adsorption of phenol and maximizes the hydrogen utilization toward ECH rather than recombination to trigger HER. As a result, the optimized Pt@TiO₂ electrocatalysts exhibit excellent electrocatalytic performance for phenol ECH to cyclohexanol with a high selectivity of 93% and appealing FE of 57%. Density functional theory calculations further confirm the optimization of interfacial electronic structure, thus evidently promoting reactants absorption and activation on the Pt@TiO₂.