Transition Metal Single-Atom Electrocatalysts for CO2 Reduction to CO

Electrocatalytic carbon dioxide reduction (ECR) technology offers a potential strategy to achieve the goal of "carbon neutralization". Transition metal single-atom catalysts have attracted much attention in ECR due to their adjustable electronic structure, high atom utilization and uniform active sites. This review firstly introduces the advantages of transition metal single-atom catalysts in CO2 reduction, especially in selective CO production. Then, the recent progress on controlling the active sites as well as the catalysis selectivity over Fe, Co, Ni and other single-atom electrocatalysts are reviewed, with special emphasis on the intermediate process control of proton coupled CO2 reduction to CO reaction path. Finally , the development direction of transition metal single-atom catalysts in ECR is briefly prospected to provide guidance and reference for promoting their large-scale application.