摘要：Electrocatalytic nitrate reduction reaction is considered as a promising and sustainable method for ammonia ***,the selectivity and yield rate of ammonia are limited by the competitive hydrogen evolution reaction and the complex eight-electron transfer ***,we developed a(FeCoNiCu)Ox/CeO_(2)polymetallic oxide electrocatalyst for effective nitrate reduction to *** synergistic effects among the multiple elements in the electrocatalyst were clearly elucidated by comprehensive ***,Cu acted as the active site for reducing nitrate to nitrite,and Co facilitated the subsequent reduction of nitrite to ammonia,while Fe and Ni promoted water dissociation to provide ***,the incorporation of CeO_(2)increased the active surface area of(FeCoNiCu)Ox,resulting in an improved ammonia yield rate to meet industrial ***,the(FeCoNiCu)Ox/CeO_(2)electrocatalyst achieved an ammonia current density of 382 mA cm^(-2)and a high ammonia yield rate of 30.3 mg h^(-1)cm^(-2)with a long-term *** work offers valuable insights for the future design of highly efficient multi-element electrocatalysts.