Generation of FeIV=O and its Contribution to Fenton‐Like Reactions on a Single‐Atom Iron−N−C Catalyst

Abstract Generating Fe IV =O on single‐atom catalysts by Fenton‐like reaction has been established for water treatment; however, the Fe IV =O generation pathway and oxidation behavior remain obscure. Employing an Fe−N−C catalyst with a typical Fe−N 4 moiety to activate peroxymonosulfate (PMS), we demonstrate that generating Fe IV =O is mediated by an Fe−N−C−PMS* complex—a well‐recognized nonradical species for induction of electron‐transfer oxidation—and we determined that adjacent Fe sites with a specific Fe 1 −Fe 1 distance are required. After the Fe atoms with an Fe 1 ‐Fe 1 distance <4 Å are PMS‐saturated, Fe−N−C−PMS* formed on Fe sites with an Fe 1 ‐Fe 1 distance of 4–5 Å can coordinate with the adjacent Fe II −N 4 , forming an inter‐complex with enhanced charge transfer to produce Fe IV =O. Fe IV =O enables the Fenton‐like system to efficiently oxidize various pollutants in a substrate‐specific, pH‐tolerant, and sustainable manner, where its prominent contribution manifests for pollutants with higher one‐electron oxidation potential.