Recent Advances in Electrochemical CO₂ -to-CO Conversion on Heterogeneous Catalysts

Electrochemical reduction of carbon dioxide (CO₂ ) to fuels and chemicals provides a promising solution for renewable energy storage and utilization. Among the many possible reaction pathways, CO₂ conversion to carbon monoxide (CO) is the first step in the synthesis of more complex carbon-based fuels and feedstocks, and holds great significance for the chemical industry. Herein, recent advances in heterogeneous catalysts for selective CO evolution from electrochemical reduction of CO₂ are described. With Au catalysts as a paradigm, principles for catalyst design including size, morphology, and grain boundary densities tuning, surface modifications, as well as metal-support interaction are comprehensively summarized, which shed light on the development of other transition metal catalysts targeting efficient CO₂ -to-CO conversion. In addition, recently emerged novel materials including transition metal single-atom catalysts, which present significantly different catalytic behaviors compared to their bulk counterparts and thus open up many unexpected opportunities, are summarized. Furthermore, the technical aspects with respect to large-scale production of CO are presented, focusing on the full-cell design and implementation. Finally, short comments related to the future direction of real-word CO₂ electrolysis for CO supply are provided in terms of catalyst optimization and technical breakthrough.