Bimetallic Cu <sub>11</sub> Ag <sub>3</sub> Nanotips for Ultrahigh Yield Rate of Nitrate‐to‐Ammonium
Changhong Wang, Zhengyang Liu, Quanxiao Peng, Dandan Xing, Tao Hu, Feng Du, Chang Ming Li, Ruguang Ma, Hongbin Yang, Chunxian Guo
Abstract
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.