Pronounced orbital-coupled asymmetrically coordinated NiCoMn heterotrimetallic atomic sites enable efficient...

Urea electrooxidation offered an energy-efficient alternative to water oxidation for hydrogen generation, but its implementation was hindered hindered by sluggish kinetics and instability under industrial current densities. We report a monolayer asymmetrically coordinated trimetallic atom sites catalyst (A-NiCoMn-TAC/LDH) with a defect-rich coordination environment. It requires 1.26 ± 0.01 V vs. RHE at 10 mA cm^-2 and maintains stability for 600 h at 500 mA cm^-2 in half-cell tests, and operates for 1500 h at an industrial level of 1000 mA cm^-2 in an anion-exchange membrane electrolyzer. X-ray absorption spectra reveal the defective coordination structures around the heterotrimetallic atoms and their electrochemical dynamic structural adaptation during the urea oxidation reaction. Through operando spectroscopy and theoretical calculations, we identify defect engineering induced strong d-p-d orbital coupling, creating a π-donation-mediated charge transfer pathway. This configuration lowers the energy barrier for the formation of CON₂* and enhances urea adsorption over OH*, enabling high-performance urea oxidation.