D-band broadening drives pollutant oxidative polymerization for intermediate-free water purification

Oxidative polymerization driven by direct electron transfer (DET) demonstrates superior selectivity and strong anti-interference capability in water purification. However, its practical application is constrained by inherent limitations, including inadequate polymerization efficiency and extent, as well as catalytic site deactivation. To address these challenges, we propose a catalytic pathway engineering strategy through D-band broadening. Building upon this principle, a cobalt-manganese oxide-modified graphite felt (Co‑MnO₂@GF) catalyst was developed and integrated into a dual-chamber reaction system. Facilitated by a downward shift of the D-band peak, surface-confined oxidative polymerization converted >94% of model pollutants into separable, potentially recoverable polymers. This yielded an effluent free of detectable intermediates and achieved near-complete removal of total organic carbon (TOC). More importantly, the electron delocalization induced by broadened D-band enables electrons derived from pollutants to migrate rapidly toward the oxidant instead of being trapped in Mn d-orbitals. This mitigates the deep reduction of Mn(IV) caused by excessive electron accumulation on Co‑MnO₂@GF, thereby stabilizing high-valence Mn species during operation and underpinning the superior long-term stability of the catalyst in oxidative polymerization. Our work demonstrates that rational electronic structure design can effectively overcome the intrinsic barriers of DET-driven oxidative polymerization, establishing a scalable purification strategy for sustainable water treatment.