LaNi0.2Cu0.8O3‐δ Perovskites as Electrocatalysts for Electro‐synthesis of Ammonia from Nitrogen Oxyanion

Abstract Electrochemical nitrate reduction to ammonia (NO3RR) has become an attractive alternative way for sustainable ammonia synthesis. The development of electrocatalysts with high activity, stability and Faradaic efficiency is important but challenge due to the complex eight‐electron process. Herein, LaNi0.2Cu0.8O2.77 (LNC) and LaNi0.2Cu0.8O2.53 (LNC−Ar) are demonstrated as electrocatalysts towards NO3RR and the surface reconstruction of the two catalysts was found to have strong effect on the catalytic performance. LNC−Ar shows a superior performance than LNC, with a maximum NH4+ yield of 11.49±1.20 mg h−1 cm−2 and a Faradaic efficiency of 87.10±1.34 % in 0.5 M NO3−, besides, the LNC−Ar remains functionally stable along the long‐time electrolysis. DFT results reveals the reconstructed LaNi0.2Cu0.8O2 (LNCO2) has the best ability to adsorb *NO3, resulting in a better performance towards NO3RR. Further, the better performance on LNC−Ar with more LNCO2 can be well explained. This work opens a new sight on perovskites towards NO3RR and provides an option of active and stable electrocatalyst for sustainable ammonia synthesis.