Local structural environment of single-atom catalysts

Single-atom catalysts (SACs) provide opportunities for bridging the gap between homogeneous and heterogeneous catalysis, facilitating the precise structural identification of the catalytically active sites, and offering new opportunities for interpreting the structure–performance relationship from the atomistic perspective. In view of this, the background of catalysis, catalysts and the history of the development of SACs are introduced in sequence. Subsequently, the correlation between the structure and performance of SACs is reviewed with respect to aspects of their local structural environment including metal single-atoms (MSA), amount of MSA loaded, electronegativity, oxidation state, coordination atom, and coordination number. By combining theoretical and experimental analyses, a deep understanding of the correlation between the structure and catalytic mechanism will shed light on the optimization and design of SACs toward high-efficiency chemical energy conversion. Finally, the whole review of SACs is summarized and future prospects are outlined.