Synergistic Metal‐Support Interaction in Ag‐SrCoO ₂ . ₅₂ Heterostructure Catalysts to Boost Electrocatalytic Nitrate Reduction to Ammonia

ABSTRACT Electrocatalytic nitrate reduction reaction (NO ₃ RR) has been considered as a green and efficient solution to maintain the balance of the global nitrogen cycle by effectively treating nitrogen pollutants and producing high‐value NH ₃ . The present work reports a facile in situ exsolution strategy to construct an Ag‐modified oxygen‐deficient strontium cobalt perovskite oxide (SrCoO _2.52 ) heterostructure catalyst. The strong interfacial electronic interaction between Ag and SrCoO _2.52 has been demonstrated experimentally and theoretically to optimize the adsorption strength of the key reaction intermediates and promote the subsequent hydrogenation by accelerating water dissociation. The optimal SrCoO _2.52 ‐0.3Ag catalyst exhibits exceptional NO ₃ RR performance with a high NH ₃ Faradaic efficiency of approximately 96.7% at −0.7 V and yield rate of 49.78 mg h ^{− 1} mg _cat ^{− 1} at −0.8 V. Moreover, the assembled Zn─NO ₃ ⁻ battery can delivers a high open‐circuit potential of 1.371 V with a maximum power density of 1.58 mW cm ^{− 2} , and a high Faradaic efficiency of 89.2% for NH ₃ production as well as commendable electrochemical stability.