▎ 摘　　要

Electrochemical conversion of N-2 to NH3 offers a clean and energy-saving solution for artificial NH3 production, but requires cost-effective, steady and highly efficient catalysts to promote N-2 reduction reaction (NRR). Herein, CuO employed as a new non-noble-metal NRR catalyst was investigated both experimentally and theoretically. When supporting the CuO nanoparticles on reduced graphene oxide (RGO), it was demonstrated that the resulting CuO/RGO nanocomposite could effectively and robustly catalyze NRR under ambient conditions. At -0.75 V versus reversible hydrogen electrode, the CuO/RGO exhibited a high NH3 yield of 1.8x10(-10) mol s(-1) cm(-2) and Faradaic efficiency of 3.9 %, along with the excellent selectivity and high stability. Density functional theory (DFT) calculations revealed that the "Suf-end" was the most effective mode for N-2 adsorption on catalytic Cu atoms. In NRR process, the alternating associative route was the preferable pathway with *N-2 ->*NNH being the rate-determining step.