Individually-atomic governing d–π* orbital interactions via Cu-promoted optimization of Fe-d band centers for high-efficiency zinc-air battery

It is challenging for precise governing of electronic configuration of the individually-atomic catalysts toward optimal electrocatalysis, as d-band configuration of a metal center determines the adsorption behavior of reactive species to the center in oxygen reduction reaction (ORR). The addition of Cu atom modifies the d-band center position of Fe central atom, thus strengthening the d–π* orbital interactions. Herein, FeCu-NC catalyst in the nitrogen-doped carbon (NC) support containing individual dual-metal CuN₄/FeN₄ sites was prepared by the surface confinement strategy of zeolitic imidazolate framework (ZIF), treated as a model catalyst. Experimentally and theoretically co-verified dual-metal CuN₄/FeN₄ sites highly dispersed in the NC support, enable transferring more electrons from FeN₄ sites to *OH intermediates, thereby accelerating the desorption process of *OH species. Superior to those commercial Pt/C, Our FeCu-NC catalyst exhibited extraordinary ORR activity (with a E_1/2 as high as 0.87 V) and cycling stability in 0.1 M KOH electrolyte, and thereof demonstrated excellent discharge performance in zinc-air batteries. Our construction of dual-atom catalysts (DACs) provides a strategy for atom-by-atom designing high-efficiency catalysts via orbital regulation.