Photoelectrochemical and electrochemical CO2 reduction to formate on post-transition metal block-based catalysts

Abstract

Photoelectrochemical or electrochemical reduction of carbon dioxide (CO₂) to produce formate is a potential strategy to reduce greenhouse gases. In the past few years, various catalysts and modification strategies have been developed to improve the selectivity and solar-to-formate conversion efficiency, accelerating the practical applications of this technology. Among them, more attention was paid to the post-transition metal block-based catalysts due to their high formate selectivity. Herein, representative post-transition metal block-based (indium (In), tin (Sn), bismuth (Bi), etc.) catalysts and engineering strategies in regulating the CO₂ reduction selectivity and activity toward formate are summarized. First, the advantages and fundamental mechanism of CO₂ reduction to formate were discussed. After that, an overview of selectivity and stability of catalysts, and in situ/operando characterization were discussed for deepening the understanding of the reaction mechanisms and catalyst design theory. Subsequently, the photoelectrochemical CO₂ reduction systems were analyzed to provide insight for designing the structure of the photoelectrochemical device or cell. To conclude, the future challenges, concerns, directions, and applications are summarized and prospected.