Asymmetric Fe–Co dual-atom sites enable electron-transfer-dominated peracetic acid oxidation

Heterogeneous activation of peracetic acid (PAA) is promising for advanced water purification but still suffers from nonselective radical production, matrix interference, and inefficient electron transfer at poorly defined sites. Here, we design an asymmetric Fe–Co dual-atom catalyst (FeCo-DAC) anchored on N-doped porous carbon, effectively steering PAA activation toward a surface-confined, electron-transfer-dominated pathway. FeCo-DAC/PAA exhibits rapid bisphenol A (BPA) degradation ( k obs =1.90 min −1 ), surpassing single-metal counterparts (Fe-SAC 1.61 min −1 ; Co-SAC 0.41 min −1 ). EPR reveal O₂•⁻dominated and ¹O₂ dominated pathways on Fe‑SAC and Co‑SAC, respectively, while FeCo‑DAC indicating an interfacial electron‑transfer‑dominated mechanism. Mechanistic analyses reveal that electronically asymmetric Fe–N 4 and Co–N₃ sites cooperatively polarize adsorbed PAA to form a high-potential intermediate, enabling direct electron transfer from BPA within a closed interfacial loop with minimal radical release. The FeCo-DAC/PAA system efficiently degrades diverse micropollutants (BPA, BPS, BPC ≈ 100 %; RhB, SMX ≥96 %) and achieves robust TOC removal (52 %-63 %) in complex real-water matrices with low metal leaching (Fe²⁺ ≈ 78.4 μg/L; Co²⁺ ≈ 189.5 μg/L). Additionally, embedding FeCo-DAC into a PVDF membrane yields continuous-flow BPA removal (95 %-100 %) over 600 min, underscoring the practical potential of this asymmetric dual-site catalyst for sustainable, selective water purification.