Modulating the Structure and Composition of Single-Atom Electrocatalysts for CO 2 reduction.

Electrochemical CO 2 reduction reaction (eCO 2 RR) is a promising strategy to achieve carbon cycling by converting CO 2 into value-added products under mild reaction conditions. Recently, single-atom catalysts (SACs) have shown enormous potential in eCO 2 RR due to their high utilization of metal atoms and flexible coordination structures. In this work, the recent progress in SACs for eCO 2 RR is outlined, with detailed discussions on the interaction between active sites and CO 2 , especially the adsorption/activation behavior of CO 2 and the effects of the electronic structure of SACs on eCO 2 RR. Three perspectives form the starting point: 1) Important factors of SACs for eCO 2 RR; 2) Typical SACs for eCO 2 RR; 3) eCO 2 RR toward valuable products. First, how different modification strategies can change the electronic structure of SACs to improve catalytic performance is discussed; Second, SACs with diverse supports and how supports assist active sites to undergo catalytic reaction are introduced; Finally, according to various valuable products from eCO 2 RR, the reaction mechanism and measures which can be taken to improve the selectivity of eCO 2 RR are discussed. Hopefully , this work can provide a comprehensive understanding of SACs for eCO 2 RR and spark innovative design and modification ideas to develop highly efficient SACs for CO 2 conversion to various valuable fuels/chemicals.