ABSTRACT Selective nonradical oxidation to enhance biodegradability is an attractive route for wastewater pretreatment, but molecular control of peroxymonosulfate (PMS) activation remains elusive. Here we report a Fe‐N 4 catalyst with second‐shell boron coordination (FeN 4 /B) synthesized by supramolecular self‐assembly. The second‐shell B imposes long‐range electronic regulation and cooperative spin alignment, shifting the Fe‐PMS * adduct to a high‐spin configuration and promoting spin‐allowed interfacial charge transfer. Concomitantly, covalent B─H bonding with PMS generates the key SO 5 * intermediate that channels PMS activation toward singlet oxygen. This structural control delivers ≥96% 1 O 2 selectivity with an observed rate constant k obs = 1. 64 min −1, a 1 O 2 production rate of 227 µmol L −1 min −1, and 98% PMS‐to‐ 1 O 2 conversion. FeN 4 /B rapidly degrades 15 highly biotoxic pollutants within 10 min and retains activity under pH fluctuations, common ion/DOM interference, and across diverse natural waters. Implemented as a hydrogel‐immobilized ALICR‐FeN 4 /B module, the catalyst operated continuously for 168 h, increased effluent biodegradability (BOD/COD > 0. 50), reduced acute toxicity, and lowered downstream biological treatment load at an estimated pretreatment cost of ∼0. 14 t −1. These results establish cooperative spin alignment as a central lever of second‐shell engineering, bridging atomistic design and scalable water treatment to enable practical, economically favorable pretreatment based on selective PMS‐to‐ 1 O 2 conversion.
Zhang et al. (Mon,) studied this question.