Modulated Fe Central Spin State in FeCu4 Alloy Nanoparticles for Efficient and Selective Activation of H2O2

Abstract

In advanced oxidation processes, the efficient activation of H₂O₂ 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 H₂O₂ activation and realize the efficient selective conversion of H₂O₂. Therefore, FeCu bimetallic active sites are developed by constructing FeCu₄ 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 ^*H₂O₂, lowered the energy barrier of intermediate products in hydroxyl radicals (·OH) generation process, achieved efficient activation of H₂O₂ 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 H₂O₂ redox relationship, promoting efficient reduction of Fe³⁺ to Fe²⁺. 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).