Electron Delocalization Realizes Speedy Fenton‐Like Catalysis over a High‐Loading and Low‐Valence Zinc Single‐Atom Catalyst.

A zinc (Zn)‐based single‐atom catalyst (SAC) is recently reported as an active Fenton‐like catalyst; however, the low Zn loading greatly restricts its catalytic activity. Herein, a molecule‐confined pyrolysis method is demonstrated to evidently increase the Zn loading to 11.54 wt.% for a Zn SAC (ZnSA‐N‐C) containing a mixture of Zn−N4 and Zn−N3 coordination structures. The latter unsaturated Zn−N3 sites promote electron delocalization to lower the average valence state of Zn in the mix‐coordinated Zn−Nx moiety conducive to interaction of ZnSA‐N‐C with peroxydisulfate (PDS). A speedy Fenton‐like catalysis is thus realized by the high‐loading and low‐valence ZnSA‐N‐C for PDS activation with a specific activity up to 0.11 min L−1 m−2, outstripping most Fenton‐like SACs. Experimental results reveal that the formation of ZnSA‐N‐C−PDS* complex owing to the strong affinity of ZnSA‐N‐C to PDS empowers intense direct electron transfer from the electron‐rich pollutant toward this complex, dominating the rapid bisphenol A (BPA) elimination. The electron transfer pathway benefits the desirable environmental robustness of the ZnSA‐N‐C/PDS system for actual water decontamination. This work represents a new class of efficient and durable Fenton‐like SACs for potential practical environmental applications. [ABSTRACT FROM AUTHOR]