Identification of Cu(111) as Superior Active Sites for Electrocatalytic NO Reduction to NH 3 with High Single-Pass Conversion Efficiency

• Published in: Angewandte Chemie International Edition 2024-03, Vol.63 (11), p.e202319135
• Main Authors: Xiao, Lei, Mou, Shiyong, Dai, Weidong, Yang, Weiping, Cheng, Qin, Liu, Siyuan, Dong, Fan
• Format: Article
• Language: English
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202319135

Opting for NO as an N source in electrocatalytic NH synthesis presents an intriguing approach to tackle energy and environmental challenges. However, blindly pursuing high NH synthesis rates and Faradaic efficiency (FE) while ignoring the NO conversion ratio could result in environmental problems. Herein, Cu nanosheets with exposed (111) surface is fabricated and exhibit a NO-to-NH yield rate of 371.89 μmol cm  h (flow cell) and the highest FE of 93.19±1.99 % (H-type cell). The NO conversion ratio is increased to the current highest value of 63.74 % combined with the development of the flow cell. Additionally, Crystal Orbital Hamilton Population (COHP) clearly reveals that the "σ-π* acceptance-donation" is the essence of the interaction between the Cu and NO as also supported by operando attenuated total reflection infrared spectroscopy (ATR-IRAS) in observing the key intermediate of NO . This work not only achieves a milestone NO conversion ratio for electrocatalytic NO-to-NH , but also proposes a new descriptor that utilizes orbital hybridization between molecules and metal centers to accurately identify the real active sites of catalysts.