Abstract
Perovskite oxides have emerged as promising electrocatalysts for the nitrate reduction reaction (NO(3)RR) to ammonia, yet their practical application is often limited by unsatisfactory ammonia selectivity, low yield, and poor suppression of competing reactions. Herein, we develop a multimetallic perovskite electrocatalyst, La(0.5)Sr(0.5)Co(0.5)Ni(0.5)O(3) (LSCNO), via a sol-gel method. Density functional theory (DFT) results show that Ni doping regulates the electronic structure of Co and shifts its d-band center upward. This optimization lowers the energy barrier of the *NO → *NOH rate-determining step and accelerates nitrate-reduction kinetics, further enhancing the intrinsic catalytic activity. As a result, LSCNO delivers a remarkable NO(3)RR performance, achieving a Faradaic efficiency of 94.96% and an NH(3) yield rate of 9475.9 μg h(-1) cm(-2) at -0.5 V vs RHE, while maintaining excellent stability during 12 consecutive cycles and prolonged operation at a current density οf 150 mA cm(-2). When implemented in a flow-cell system, compared to H-type electrolytic cells, the catalyst enables a steady increase in the ammonia yield at lower potential. Furthermore, a Zn-NO(3) (-) battery assembled with an LSCNO cathode delivers a peak power density of 10.19 mW cm(-2) and outstanding long-term cycling durability over 10,000 min. These results highlight LSCNO as a highly efficient and stable catalyst for nitrate-to-amine conversion, demonstrating significant potential for practical nitrogen-resource recovery and sustainable energy storage.