Bimetallic Cu 11 Ag 3 Nanotips for Ultrahigh Yield Rate of Nitrate‐to‐Ammonium

Abstract Electrochemical reduction of nitrate to ammonia (NRA) offers a sustainable approach for NH 3 production and NO 3 − removal but suffers from low NH 3 yield rate (<1.20 mmol h −1 cm −2 ). We present bimetallic Cu 11 Ag 3 nanotips with tailored local environment, which achieve an ultrahigh NH 3 yield rate of 2.36 mmol h −1 cm −2 at a low applied potential of −0.33 V vs. RHE, a high Faradaic efficiency (FE) of 98.8 %, and long‐term operation stability at 1800 mg‐N L −1 NO 3 − , outperforming most of the recently reported catalysts. At a NO 3 − concentration as low as 15 mg‐N L −1 , it still delivers a high FE of 86.9 % and an NH 3 selectivity of 93.8 %. Finite‐element method and density functional theory calculations reveal that the Cu 11 Ag 3 exhibits reduced adsorption energy barrier of *N intermediates, favorable water dissociation for *H generation and high energy barrier for H 2 formation, while its tip‐enhanced enrichment promoting NO 3 − accumulation.