Single‐Atom Catalysts for Converting CO2 Into High Value‐Added Products: From Photocatalysis and Electrocatalysis to Photoelectrocatalysis

Converting CO2 into valuable products via photo‐, electro‐, and photoelectrocatalysis offers the possibility of simultaneously mitigating global warming and energy shortages. Single‐atom catalysts (SACs) have garnered significant interest from researchers owing to their optimal atom use, suitable coordination environments, distinctive electronic structures, and highly dispersed active sites. This work offers a thorough examination of the progress of research on SACs for photo‐, electro‐, and photoelectrocatalytic conversion of carbon dioxide. The fundamental concepts of photo‐, electro‐, and photoelectrocatalytic reduction of CO2 are briefly described, respectively. Secondly, the preparation approaches and characterization techniques of SACs are summarized, with a focus on how to increase the single‐atom loading rate and achieve scale‐up preparation. Finally, the specific applications of SACs for photo‐, electro‐, and photoelectrocatalytic conversion of CO2 are discussed, and the future development of SACs in the field of CO2 catalytic reduction is summarized and prospected. This study aims to provide guidance and insights for the systematic design of SACs used in CO2 reduction reactions, serving as a reference for the further advancement of photo‐, electro‐, and photoelectrocatalytic reduction of CO2.