Perovskite Oxide as A New Platform for Efficient Electrocatalytic Nitrogen Oxidation.

Electrocatalytic nitrogen oxidation reaction (NOR) offers an efficient and sustainable approach for conversion of widespread nitrogen (N2) into high‐value‐added nitrate (NO3−) 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 N2 and the competitive oxygen evolution reaction, the kinetics of NOR process is extremely sluggish accompanied with low Faradaic efficiencies and NO3− yield rates. In this work, an oxygen‐vacancy‐enriched perovskite oxide with nonstoichiometric ratio of strontium and ruthenium (denoted as Sr0.9RuO3) was synthesized and explored as NOR electrocatalyst, which can exhibit a high Faradaic efficiency (38.6 %) with a high NO3− yield rate (17.9 μmol mg−1 h−1). The experimental results show that the amount of oxygen vacancies in Sr0.9RuO3 is greatly higher than that of SrRuO3, following the same trend as their NOR performance. Theoretical simulations unravel that the presence of oxygen vacancies in the Sr0.9RuO3 can render a decreased thermodynamic barrier toward the oxidation of *N2 to *N2OH at the rate‐determining step, leading to its enhanced NOR performance. [ABSTRACT FROM AUTHOR]