Boosting Nitrate Reduction through Ru‐CO ₃ ²⁻ Microenvironment Modulated Hydrogen‐Bond Networks

Abstract Electrocatalytic reduction of nitrate (NO 3 − )‐rich wastewater to ammonia (NH 3 ) offers an attractive and sustainable strategy for green and cost‐effective NH 3 synthesis. However, slow proton transfer kinetics remains a persistent challenge, limiting both reaction activity and selectivity. We develop a strategy of leveraging anion (CO 3 2− )‐modulated microenvironments around single‐atom (ruthenium, Ru) sites to accelerate proton transfer leveraging. By modulating the electrolyte composition, we constructed a Ru‐CO 3 2− microenvironment that facilitated a highly interconnected hydrogen‐bond (H‐bond) network and promoted proton transfer kinetics. This microenvironment significantly enhanced electrocatalytic performance, enabling an NH 3 production of 76.36 mg·h −1 ·mg cat. −1 with a Faradaic efficiency (FE) exceeding 90% for NO 3 RR in an integrated electrocatalytic system. This approach offers a cost‐effective and practical strategy for converting NO 3 − ‐rich wastewater into valuable NH 3 , while providing mechanistic insights into proton transfer and interfacial regulation.