Perovskite Oxide as A New Platform for Efficient Electrocatalytic Nitrogen Oxidation

Abstract Electrocatalytic nitrogen oxidation reaction (NOR) offers an efficient and sustainable approach for conversion of widespread nitrogen (N 2 ) into high‐value‐added nitrate (NO 3 − ) under mild conditions, representing a promising alternative to the traditional approach that involves harsh Haber–Bosch and Ostwald oxidation processes. Unfortunately, due to the weak absorption/activation of N 2 and the competitive oxygen evolution reaction, the kinetics of NOR process is extremely sluggish accompanied with low Faradaic efficiencies and NO 3 − yield rates. In this work, an oxygen‐vacancy‐enriched perovskite oxide with nonstoichiometric ratio of strontium and ruthenium (denoted as Sr 0.9 RuO 3 ) was synthesized and explored as NOR electrocatalyst, which can exhibit a high Faradaic efficiency (38.6 %) with a high NO 3 − yield rate (17.9 μmol mg −1 h −1 ). The experimental results show that the amount of oxygen vacancies in Sr 0.9 RuO 3 is greatly higher than that of SrRuO 3 , following the same trend as their NOR performance. Theoretical simulations unravel that the presence of oxygen vacancies in the Sr 0.9 RuO 3 can render a decreased thermodynamic barrier toward the oxidation of *N 2 to *N 2 OH at the rate‐determining step, leading to its enhanced NOR performance.