Intrinsic Electrocatalytic Activity Regulation of M–N–C Single‐Atom Catalysts for the Oxygen Reduction Reaction

Abstract

Sustainable energy supply and sufficient chemical production are highly dependent on many essential catalytic processes for our sustainable society. On pursuing next‐generation catalysts, single‐atom catalysts (SACs) with high‐active sites atomically dispersed on substrates exhibit unique advantages regarding the maximum atomic efficiency, abundant chemical structures, and extraordinary catalytic performances for multiple vital reactions. In particular, M–N–C SACs (where M is a transition metal atom) demonstrate the optimal electrocatalytic activity for oxygen reduction reaction (ORR) and have attracted extensive attentions recently. Despite the substantial efforts on fabricating various M–N–C SACs, principles of regulating the intrinsic electrocatalytic activity of the M–N–C active sites are not yet sufficiently emphasized. In this review, regulation strategies of promoting the intrinsic electrocatalytic ORR activity of M–N–C SACs are summarized by modulating the center metal atoms, the coordinated atoms, the environmental atoms, and the guest groups, respectively. Theoretical calculations and experimental investigations are both included to afford comprehensive understandings on the structural‐performance relationship. Finally, future directions of developing advanced M–N–C SACs for electrocatalytic ORR and other analogous reactions are proposed.