Boosting High‐Valent Fe═O Formation via Fe Electron Localization in Asymmetric FeMo Dual‐Atom Catalyst for Fenton‐Like Reaction

High-valent Fe═O species, recognized as pivotal reactive oxygen intermediates in the catalyst-activated peroxymonosulfate (PMS) oxidation system, play a dominant role in contaminant degradation. However, the inherent correlation between the Fe 3d electronic structure of heterogeneous catalysts and the generation efficiency of high-valent Fe═O remains unclear, limiting the rational design of high-performance catalysts. To the end, Fe-Mo dual-atom catalysts (FeMoNC) with N₃Fe-O-MoN₂ configurations are constructed, which exhibit exceptional sulfadiazine (SDZ) degradation activity (k = 0.92 min^-1). This performance surpasses that of monometallic FeNC (1.67 times), attributed to the optimized generation of high-valent Fe═O species. Combined XPS/XAS analysis and DFT calculations reveal that electron transfer from Mo to Fe upshifts the Fe d-band center by 0.144 eV, which facilitates O_γ-O_β bond cleavage in PMS (energy barrier reduced by 31%) and stabilizes high-valent Fe═O species. The electronic modifications further confirm the promoted high-valent Fe═O formation. This work elucidates the electronic origin of high-valent Fe═O generation in heteronuclear dual-atom catalysts, providing a universal strategy for manipulating 3d-electron configurations to enhance high-valent metal-oxo chemistry in advanced oxidation processes.