Ko Byung Hee, Hasa Bjorn, Shin Haeun, Zhao Yaran, Jiao Feng
Center for Catalytic Science and Technology, Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware 19716, United States.
J Am Chem Soc. 2022 Jan 26;144(3):1258-1266. doi: 10.1021/jacs.1c10535. Epub 2022 Jan 11.
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 NO 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.
减少氮氧化物（NO）排放对于应对全球变暖及改善空气质量至关重要。传统的用于排放控制的NO减排技术在近环境温度下效率较低。在此，我们展示了一种电化学途径来还原气态NO，该途径可在环境条件下以高反应速率（400 mA cm）进行。评估了各种过渡金属用于NO和NO的电化学还原，以揭示电催化剂在决定产物选择性方面的作用。具体而言，Cu在NO电还原中对NH形成具有高度选择性，法拉第效率>80%。此外，NO电还原的分压研究表明，高NO覆盖率有利于N-N偶联反应。在酸性电解质中，NH的形成非常有利，而N的生成受到抑制。通过使用流动电化学质谱进行了额外的机理研究，以进一步深入了解反应途径。这项工作为利用可再生电力在环境条件下减少气态NO排放提供了一条有前景的途径。
