Reasonable active site design for promoting water dissociation and carbon monoxide activation in a low-temperature water-gas shift reaction

Abstract

To solve the energy crisis, the water–gas shift reaction (WGSR) has been systematically studied for the effective production of pure hydrogen and removal of hazardous carbon monoxide. In typical industrial applications, the WGSR commonly consists of two individual processes: a high-temperature shift reaction (320–450 °C) for a high reaction rate and a low-temperature shift reaction (150–300 °C) for high conversion due to their intrinsic thermodynamic and kinetic properties. Owing to the complexity of a traditional catalytic system, researchers have made great efforts to seek low-temperature (<300 °C) reaction catalysts with better performance and energy efficiency. Recent advancements have mainly focused on the correlation of the catalyst components and reactivities for low-temperature WGSR. In contrast, this work considers different catalyst design ideas for enhancing the low-temperature WGSR performance based on the combination of two half-reactions, namely, water dissociation and carbon monoxide activation, which occur on different active sites. Therefore, only an intentional design of the active sites for the two half-reactions can constitute an efficient catalyst. This review aims to summarize the advances made in the recent decade and provides some direction toward possible active site designs for future investigation.