Recent advances in application of tandem catalyst for electrocatalytic CO2 reduction

Electrocatalytic CO2 reduction reaction (CO2RR) is one of the important ways to achieve the goal of CO2 utilization and synthesizing high-value products. Electrochemical CO2RR involves multiple electron-proton transfer steps, resulting in low yield and low selectivity. *CO is considered as the key intermediate, the process of CO2RR can be divided into a tandem step of CO2-to-CO and CO-to-C2+. To promote kinetic rate of whole reaction and improve faraday efficiency of the product, tandem catalysts are constructed. Here, the recent advances in application of tandem catalyst for electrocatalytic CO2RR are reviewed for three aspects: (1) tandem mechanism of electrochemical CO2RR; (2) copper-based tandem catalysts as well as other copper-free tandem catalysts for electrochemical CO2RR; (3) challenges, opportunities and prospects of tandem catalysts for CO2RR. This review provides a comprehensive understanding tandem electrocatalytic mechanism of tandem catalysts for CO2RR and important guidelines for the field of electrocatalysis.