Energy‐Efficient Electro‐Fenton Oxidation Enabled by CoCu Dual‐Atom Catalysts with High Oxygen Utilization

Abstract

Abstract The Electro‐Fenton (EF) technique offers a promising strategy for recalcitrant organic pollutant removal by coupling the two‐electron oxygen reduction reaction (2e – ORR) for H 2 O 2 synthesis with its subsequent activation to •OH via one‐electron (1e – ) reduction. To address the distinct favorable active sites and mismatched selectivity between 2e – ORR and 1e – H 2 O 2 activation, we develop an integrated 2 + 1e – tandem ORR catalyst with CoCu diatomic pairs (CoCu‐DACs‐CN) and cyano modification to improve oxygen capture and utilization efficiency (OUE, 39.8%). The CoCu‐DACs‐CN‐based EF system achieves 100.0% of bisphenol A (BPA) in 40.0 min with a high‐rate constant of k  = 0.57 min −1 . Theoretical calculations indicate that the −CN moieties in CoCu‐DACs‐CN greatly facilitate O 2 adsorption, which further migrates to the Co site to proceed 2e – ORR with a reduced energy barrier. The generated H 2 O 2 spontaneously migrates to the surrounding Cu site for in situ activation to generate •OH. Long‐term operation of a CoCu‐DACs‐CN‐equipped flow‐cell device that maintains 100.0% bisphenol A removal even without O 2 /air pumping. Technoeconomic analysis indicates that the CoCu‐DACs‐CN‐based EF process effectively reduced electrical energy consumption by 74.4%, demonstrating its promise for energy‐efficient wastewater treatment.