Dynamic Coordination Structure Evolutions of Atomically Dispersed Metal Catalysts for Electrocatalytic Reactions

Single-atom catalysts (SACs) are regarded as promising electrocatalysts for various reactions in the field of energy conversion and storage owing to their maximized atom utilization efficiency and unique electronic properties. The modifications of local coordination structures of single metal centers play significant roles in dominating catalytic performances, thus the SACs are resurveyed with different local coordination environments in order to explore such a paramount structure–performance relationship in various energy-conversion reactions, including O₂/CO₂ reduction reaction and hydrogen evolution reaction. Notably, the atomically dispersed metal atoms that are subject to working conditions will undergo dynamic changes and then affect the catalytic properties, consequently, understanding the dynamic nature of SACs during reactions is highly significant but is still lacking to date. To this endeavor, this review particularly summarizes the dynamic evolutions of local coordination structures of SACs in various electrochemical reactions based on advanced operando/in situ techniques, aiming to precisely demonstrate the correlation between the dynamic coordination environment of SACs and the electrocatalytic activity. Finally, the challenges and perspectives are highlighted in the mechanistic studying for understanding the accurate active sites of SACs under realistic working conditions.