Ampere-level current density ammonia electrochemical synthesis using CuCo nanosheets simulating nitrite reductase bifunctional nature

• Published in: Nature communications Vol. 13; no. 1; pp. 7899 - 13
• Main Authors: Fang, Jia-Yi, Zheng, Qi-Zheng, Lou, Yao-Yin, Zhao, Kuang-Min, Hu, Sheng-Nan, Li, Guang, Akdim, Ouardia, Huang, Xiao-Yang, Sun, Shi-Gang
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 22.12.2022; Nature Publishing Group; Nature Portfolio
• Subjects: 119/118; 140/131; 140/133; 140/146; 140/58; 147/135; 147/28; 147/3; 639/301/299/886; 639/638/161/886; 704/172/169/896; Adsorption; Ammonia; Bimetals; Carbon; Catalysts; Chemical synthesis; Copper; Current density; Electrocatalysts; Electrochemistry; Environmental protection; Fourier transforms; Humanities and Social Sciences; Hydrogenation; Infrared spectroscopy; multidisciplinary; Nanoparticles; Nanosheets; Nitrates; Nitrite reductase; Nitrite Reductases; Nitrites; Nitrogen dioxide; Raman spectroscopy; Reductases; Science; Science (multidisciplinary); Selectivity; Spectrum analysis
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-022-35533-6

The development of electrocatalysts capable of efficient reduction of nitrate (NO 3 − ) to ammonia (NH 3 ) is drawing increasing interest for the sake of low carbon emission and environmental protection. Herein, we present a CuCo bimetallic catalyst able to imitate the bifunctional nature of copper-type nitrite reductase, which could easily remove NO 2 − via the collaboration of two active centers. Indeed, Co acts as an electron/proton donating center, while Cu facilitates NO x − adsorption/association. The bio-inspired CuCo nanosheet electrocatalyst delivers a 100 ± 1% Faradaic efficiency at an ampere-level current density of 1035 mA cm −2 at −0.2 V vs . Reversible Hydrogen Electrode. The NH 3 production rate reaches a high activity of 4.8 mmol cm −2 h −1 (960 mmol g cat −1 h −1 ). A mechanistic study, using electrochemical in situ Fourier transform infrared spectroscopy and shell-isolated nanoparticle enhanced Raman spectroscopy, reveals a strong synergy between Cu and Co, with Co sites promoting the hydrogenation of NO 3 − to NH 3 via adsorbed *H species. The well-modulated coverage of adsorbed *H and *NO 3 led simultaneously to high NH 3 selectivity and yield. Electroreduction of NO 3 − to NH 3 is drawing increasing interest. Here, the authors designed a CuCo catalyst imitating the bifunctional nature of Cu-type nitrite reductase to deliver an ampere-level current density for NH 3 formation.