Modulated Fe Central Spin State in FeCu ₄ Alloy Nanoparticles for Efficient and Selective Activation of H ₂ O ₂

Abstract In advanced oxidation processes, the efficient activation of H 2 O 2 and the selective production of reactive oxygen species are the key steps to achieve the removal of organic pollutants in the water environment. Studies have shown that the precise regulation of catalyst metal active sites can break through the limitation of H 2 O 2 activation and realize the efficient selective conversion of H 2 O 2 . Therefore, FeCu bimetallic active sites are developed by constructing FeCu 4 alloy nanocluster metal catalyst (FeCu/NC). The introduction of Cu metal sites realized charge redistribution, promoted rapid electron transfer, reduced the spin state of Fe in the catalyst, diminished the interaction between Fe and O, weakened the strong and persistent adsorption between Fe center and * H 2 O 2 , lowered the energy barrier of intermediate products in hydroxyl radicals (·OH) generation process, achieved efficient activation of H 2 O 2 and selective generation of ·OH. In addition, a complete electron circulation path is formed between FeCu active sites and the substrate, breaking the contradiction between single metal and H 2 O 2 redox relationship, promoting efficient reduction of Fe 3+ to Fe 2+ . The first‐order kinetic constant ( k obs ) of FeCu/NC is 0.081 min −1 , which is 3.68 and 7.36 times higher than those of single Fe metal species (FeFe/NC) and single Cu metal species (CuCu/NC) catalysts, respectively, and has excellent catalytic performance).