Low-Temperature Reverse Water–Gas Shift Catalysis Enabled by Cooperative Pt Nanoclusters and Oxygen Vacancies on La-Doped Ceria

Abstract

Doping ceria (CeO2) with La3+ increases the concentration of oxygen vacancies (Ov) and reconstructs the surface structure, creating Ce–O–La interfacial motifs that robustly anchor Pt nanoclusters (Ptnc). Here, we present a nanocluster- and vacancy-engineered Ptnc/LaCeOx catalyst that exhibits outstanding performance in the reverse water–gas shift (rWGS) reaction via a direct CO2 dissociation mechanism. Combined experimental and density functional theory studies elucidate the cooperative roles of Pt species and Ov in promoting rWGS activity. LaCeOx activates CO2 through Ov-mediated adsorption, while Ptnc facilitates H2 dissociation and promotes CO* formation and desorption. This interfacial coupling accelerates rWGS kinetics while suppressing CO hydrogenation into CH4, thereby enabling high CO selectivity and enhanced durability at comparatively low temperatures relative to Pt nanoparticles supported on stoichiometric CeO2 (Ptnp/CeO2). These findings demonstrate the key role of catalyst dynamics and establish vacancy-modulated nanocluster–support interactions as a powerful design principle for the rWGS reaction.