“Capture-Backdonation-Recapture” Mechanism for Promoting N2 Reduction by Heteronuclear Metal-Free Double-Atom Catalysts

• Published in: Journal of the American Chemical Society 2022-06, Vol.144 (21), p.9344-9353
• Main Authors: Wu, Yibo, He, Cheng, Zhang, Wenxue
• Format: Article
• Language: English
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/jacs.2c01245

Facing the increasingly serious energy and environmental crisis, the development of heteronuclear metal-free double-atom catalysts is a potential strategy to realize efficient catalytic nitrogen reduction with low energy consumption and no pollution because it could combine the advantages of flexible active sites in double-atom catalysts while also being pollution-free and have high Faraday efficiency in metal-free catalysts simultaneously. However, according to the existing mechanism, the finite orbits of other nonmetallic atoms, except the boron atom, reduce the possibility of metal-free catalysis and hinder the development of heteronuclear metal-free double-atom catalysts. Herein, we propose a new “capture-backdonation-recapture” mechanism, which skillfully uses the electron capture-backdonation-recapture between boron, the substrate, and other nonmetallic elements to solve the above problems. Based on this mechanism, by means of the first-principle calculations, the material structure, adsorption energy, catalytic activity, and selectivity of 36 catalysts are systematically investigated to evaluate their catalytic performance. B–Si@BP1 and B–Si@BP3 are selected for their good catalytic performance and low limiting potentials of −0.14 and −0.10 V, respectively. Meanwhile, the “capture-backdonation-recapture” mechanism is also verified by analyzing the results of adsorption energy and electron transfer. Our work broadens the ideas and lays the theoretical foundation for the development of heteronuclear metal-free double-atom catalysts in the future.