Photo-Enhanced Electronic Metal-Support Interaction Boosts Low-Temperature Water-Gas Shift Reaction via Niδ+-OV-Ce3+ Interfacial Redox Cycling.

Abstract

Nickel (Ni) is an attractive non-noble-metal catalyst for the water-gas shift reaction (WGSR), yet strong CO adsorption and competing methanation severely limit its activity and selectivity. Herein, we develop a series of NiCe layered double hydroxide-derived catalysts (NCO-T) through reduction-induced Ni exsolution. The optimized NCO-450 catalyst achieves 92.53% CO conversion and an H2 production rate of 103.24 µmol·gcat -1·s-1 at ambient pressure and a catalyst temperature of 83°C. In situ spectroscopic analyses and theoretical calculations reveal that isolated interfacial oxygen vacancies (OVs) stabilize the active Niδ+─OV─Ce3+ motif responsible for the superior WGSR performance. Photoexcitation-induced directional interfacial charge transfer from Ni to CeO2- x enhances the electronic metal-support interaction and continuously regenerates this active interfacial state, thereby moderating CO adsorption, promoting H2O activation, and suppressing competing methanation. This work offers a rational design strategy for developing low-cost transition-metal catalysts with superior low-temperature activity and high selectivity.