Optimizing Local Configuration of Interphase Copper Oxide by Ru Atoms Incorporation for High‐Efficient Nitrate Reduction to Ammonia

Abstract The electrochemical reduction of nitrate offers an environmentally friendly and sustainable development strategy to mitigate nitrate pollution and further facilitate value‐added ammonia synthesis. Here, interphase Cu 2+1 O (regarded as Cu 2 O with metal excess defects) featured by abundant Cu 0 and Cu δ+ sites with Ru single atoms incorporation (marked as Ru SA @Cu 2+1 O) are synthesized by fast Joule heating method for efficient nitrate reduction to ammonia. The X‐ray absorption spectroscopy found that the incorporation of Ru atoms can effectively tune the local electronic structure of Cu 2+1 O substrate with charge polarization. The as‐prepared Ru SA @Cu 2+1 O exhibits a remarkable Faradaic efficiency (FE) of 98.02% and an ammonia yield of 0.81 mmol h −1 cm −2 at the potential of ‐0.4 V (vs RHE). In situ, attenuated total reflection surface‐enhanced infrared absorption spectroscopy and theoretical investigations further confirm that Ru incorporation promotes the rapid transfer of the hydrogenation process. This study not only presents a feasible approach for fabricating interphase catalysts through fast Joule heating synthesis, but also offers insights into effectively regulating the local electronic structure of electrocatalysts for boosted reaction process.