Efficient ambient ammonia synthesis by Lewis acid pair over cobalt single atom catalyst with suppressed proton reduction. Issue 15 (16th March 2022)

• Record Type: Journal Article
• Authors: Tran, Ngoc Quang; Liu, Xinghui; Cho, Yunhee; Duy, Le Thai; Zheng, Lirong; Yu, Jianmin; Ajmal, Sara; Shao, Xiaodong; Lee, Jinsun; Lee, Hyoyoung
• Is Part Of: Journal of materials chemistry. Volume 10:Issue 15(2022)
• Page Start: 8432
• Page End: 8439
• Publication Date: 2022-03-16
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d2ta00308b
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : A Lewis acid pair over a single Co atom anchored on sponge-like nitrogen-doped mesoporous hollow carbon nanofibers was designed. The catalyst exhibits an NH3 production rate of 67.6 μg h −1 mg −1 and a maximum Faraday efficiency of 56.9% at a peak potential of −0.1 V vs. RHE. Abstract : Improving the ammonia yield and Faraday efficiency of ambient electrochemical nitrogen fixation is a priority for altering the energy-intensive Haber–Bosch process. In this work, positively charged single cobalt atoms anchored on sponge-like nitrogen-doped mesoporous interconnected hollow carbon nanofibers (serving as a Lewis acid pair) were intentionally designed as catalytic centers that can suppress the side effect of the competing hydrogen evolution reaction and simultaneously boost the electrochemical conversion of nitrogen (N2 ) to ammonia (NH3 ). The Lewis acid pair catalyst exhibits an NH3 production rate of 67.6 μg h −1 mg −1 and a maximum Faraday efficiency of 56.9% at a peak potential of −0.1 V vs. RHE, which outperforms previously reported nitrogen reduction reaction (NRR) catalysts. First-principles DFT calculations suggest the regulation of the local electronic structure that induces Lewis acid pair formation upon charge transfer between the single Co atom and substrate, confirming a high intrinsic NRR by both experiments and theoretical calculations.