Beyond mechanistic insights, this work demonstrates the practical utility of Co₁CNCl/S in real water systems. The catalyst maintains high activity in diverse water matrices and shows excellent reusability and scalability, enabling continuous flow treatment of 189.6 L g^-1 with minimal cost ($0.22 per ton of treated water). The Cl/S bicoordination creates a cooperative electronic environment that modulates the oxidation state and reactivity of the Co site. Axial Cl induces electron withdrawal, raising the oxidation state and shifting the d-band center, while second-shell S doping stabilizes the high-valent Co intermediate via π-backdonation. This facilitates PMS* adsorption and stabilizes the ETP route over radical-based mechanisms. This study exemplifies how precise spatial and electronic engineering of SACs can fundamentally redirect reaction pathways, favoring non-radical routes with improved selectivity and stability. The axial–second-shell coordination strategy opens new directions in the design of robust, high-performance SACs for environmental remediation and beyond. Future efforts may extend this concept to other redox reactions and SAC platforms, integrating dynamic in situ characterizations and computational modeling to accelerate the development of intelligent, function-oriented catalytic materials.