Electrochemical Reduction of Gaseous Nitrogen Oxides on Transition Metals at Ambient Conditions

• Published in: Journal of the American Chemical Society Vol. 144; no. 3; pp. 1258 - 1266
• Main Authors: Ko, Byung Hee, Hasa, Bjorn, Shin, Haeun, Zhao, Yaran, Jiao, Feng
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 26.01.2022
• Subjects: air quality; electrochemistry; mass spectrometry; nitrogen; partial pressure; renewable electricity
• ISSN: 0002-7863; 1520-5126; 1520-5126
• DOI: 10.1021/jacs.1c10535

Mitigating nitrogen oxide (NO ) emissions is critical to tackle global warming and improve air quality. Conventional NO abatement technologies for emission control suffer from a low efficiency at near ambient temperatures. Herein, we show an electrochemical pathway to reduce gaseous NO that can be conducted at high reaction rates (400 mA cm ) under ambient conditions. Various transition metals are evaluated for electrochemical reduction of NO and N O to reveal the role of electrocatalyst in determining the product selectivity. Specifically, Cu is highly selective toward NH formation with >80% Faradaic efficiency in NO electroreduction. Furthermore, the partial pressure study of NO electroreduction revealed that a high NO coverage facilitates the N-N coupling reaction. In acidic electrolytes, the formation of NH is greatly favored, whereas the N production is suppressed. Additional mechanistic studies were conducted by using flow electrochemical mass spectrometry to gain further insights into reaction pathways. This work provides a promising avenue toward abating gaseous NO emissions at ambient conditions by using renewable electricity.