Electronic Structure Engineering of Cu-Doped CoP Synergistically Steering Hydrogen Transfer for Efficient Electrosynthesis of Ammonia

Ammonia, as a crucial feedstock in the chemical industry, is traditionally synthesized via the energy-intensive and high-carbon-emission Haber–Bosch process, which contradicts sustainable development goals. The electrocatalytic nitrate reduction reaction (NO 3 RR) for ammonia synthesis has emerged as a research hotspot due to its low energy consumption and environmental friendliness. However, existing catalysts still suffer from high overpotentials, competitive hydrogen evolution reaction (HER), and intermediate accumulation. In this study, we successfully fabricated copper-doped cobalt phosphide (Cu-CoP) catalysts through hydrothermal and phosphidation strategies, systematically investigating their NO 3 RR performance and mechanism. Experimental results demonstrate that Cu-CoP exhibits exceptional catalytic activity at −0.65 V vs RHE, achieving a Faradaic efficiency of 96.2% and an ammonia production rate of 7.06 mg cm –2 h –1, significantly outperforming undoped CoP catalysts. Through comprehensive characterization and theoretical calculations, we reveal that Cu incorporation not only optimizes the electronic structure of Co sites to facilitate water dissociation and *H generation, but also enables efficient nitrate adsorption at Cu sites while suppressing *H dimerization, thereby synergistically enhancing NO 3 RR selectivity and kinetics. This work provides insights for designing high-performance nonprecious metal NO 3 RR catalysts and elucidates the cooperative mechanism of dual active sites.