Enhancing 1O2 Generation Performance by Regulating C and N Coordination for Efficient Fenton‐Like Catalytic Process

Abstract Singlet oxygen ( 1 O 2 ), a vital reactive species, exhibits excellent organic pollutant degradation selectivity in Fenton‐like reactions. Recognizing and controlling the structure‐activity relationship of single‐atom catalysts (SACs) is essential to achieving the highly efficient and selective generation of 1 O 2 for various practical applications. Here, three iron single‐atom catalysts with different coordination configurations (Fe SAC ─N 4 , Fe SAC ─N 3 ‐C 1, and Fe SAC ─N 2 ─C 2 ) are prepared to modulate the selective generation of 1 O 2 by activating peroxymonosulfate (PMS). Replacing N coordinated to Fe atoms with C increases 1 O 2 selective generation thus enhancing the Fenton‐like reaction activity. Specifically, Fe SAC ─N 2 ─C 2 presents the optimal catalytic activity, high stability, and environmental tolerance. Moreover, the 1 O 2 selectivity increases as the N coordination number decreases, which is in the order of Fe SAC ─N 4 (73%) < Fe SAC ─N 3 ─C 1 (82%) < Fe SAC ─N 2 ─C 2 (90%). DFT calculations demonstrate that replacing N with C enhances the electrophilicity and electron transfer capacity, optimizes the d‐band center, facilitates reactant adsorption, and reduces the energy barrier, thus facilitating 1 O 2 production and enhancing the Fenton‐like reaction activity. This study reveals the underlying catalytic trends and mechanisms of catalyst structure‐activity relationships for high selective generation of 1 O 2 by PMS activation, thus providing guidance for developing catalysts capable of highly selective organic pollutant degradation.