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.