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

Abstract

AbstractGenerating FeIV=O on single‐atom catalysts by Fenton‐like reaction has been established for water treatment; however, the FeIV=O generation pathway and oxidation behavior remain obscure. Employing an Fe−N−C catalyst with a typical Fe−N4moiety to activate peroxymonosulfate (PMS), we demonstrate that generating FeIV=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 Fe1−Fe1distance are required. After the Fe atoms with an Fe1‐Fe1distance <4 Å are PMS‐saturated, Fe−N−C−PMS* formed on Fe sites with an Fe1‐Fe1distance of 4–5 Å can coordinate with the adjacent FeII−N4, forming an inter‐complex with enhanced charge transfer to produce FeIV=O. FeIV=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.