Iron-Induced Interfacial Electronic Asymmetry Steers Pathway Divergence in Cobalt-Centered Fenton-Like Catalysis

Deep mineralization and matrix tolerance are difficult to reconcile in advanced oxidation processes because radical and nonradical pathways are often coupled in a composition-defined paradigm. Although multimetal materials can catalyze both pathways, the parallel reactions typically occur at different active sites, and their relative contributions are often governed by catalyst composition and active-site distribution, making deliberate regulation of pathway competition difficult. Here, we propose a multimetal catalyst with an electronically asymmetric Fe─O─Co interface to enable pathway divergence within a Co-centered catalytic environment. Fe introduction into CoNi layered hydroxides leads to electron density redistribution at neighboring Co sites and shifts PMS activation from a high-valent Co^IV═O-biased route toward a sulfate-radical-enriched regime while retaining complementary nonradical oxidation. The optimized catalyst achieved 1.43-fold greater TOC removal and a 1.47-fold higher PMS utilization efficiency (PUE) for norfloxacin (NOR) degradation than the Fe-free control, with robust decontamination performance against common background matrix interference and sustained activity over 96 h of high-flux continuous-flow operation. This work establishes interfacial Fe regulation as a pathway-engineering strategy for steering oxidant-activation selectivity through heterometal-induced electronic asymmetry, providing a route to reconcile mineralization depth with matrix tolerance in Fenton-like water treatment.