Computational Insight into Metallated Graphynes as\nSingle Atom Electrocatalysts for Nitrogen Fixation

Abstract

The electrochemical nitrogen reduction\nreaction (NRR) is expected\nto achieve sustainable ammonia synthesis via direct nitrogen fixation;\nhowever, the high-quality catalysts that play a crucial role in the\nNRR are still lacking. The emerging transition metal–1,3,5-triethynylbenzene\n(TM-TEB) frameworks offer attractive possibilities in the electrochemical\ncatalysis due to the featured atomic and electronic structures. This\nwork presents a comprehensive first-principles study of the TM-TEB\nsystems for TMs from the first three d-block series and systematically\nexplores their potential applications as NRR electrocatalysts. By\ndesigning a hierarchical screening strategy, the TM-TEB systems are\nevaluated based on the NRR catalytic activity as well as the competition\nfrom the hydrogen evolution reaction. In addition, in order to have\na deeper understanding of the catalytic activities of the TM-TEB systems,\ndiverse possible NRR paths on the TM-TEB surfaces are completely analyzed\nas well. Our analysis reveals that the TM-TEB systems with TM = V,\nMo, Tc, W, and Os are electrocatalysts with a high NRR catalytic activity,\nwhile among them, only Mo- and V-TEB show promising NRR selectively.\nThis work demonstrates the great potential of the TM-TEB systems as\nelectrocatalysts in the NRR process, which improves the understanding\nof the TM-TEB systems and can motivate further exploration of their\napplication in catalysis.