Computational screening of pyrazine-based graphene-supported transition metals as single-atom catalysts for the nitrogen reduction reaction.

Electrochemical synthesis of NH from N utilizing single-atom catalysts (SACs) is a promising strategy for industrial nitrogen fixation and chemical raw material production. In this work, single transition metals (TMs) anchored on pyrazine-based graphene (TM@py-GY) are systematically studied to screen potential electrocatalysts for the nitrogen reduction reaction (NRR) using first-principles calculations. Particularly, the descriptor related to electronegativity and valence electron number is selected to clarify the trend of NRR activity, realizing a fast-scan/estimation among various candidates. After a four-step screening process, W@py-GY and Mo@py-GY SACs are screened with good structural stability, high selectivity, and high activity. Meanwhile, the thermodynamic stability of W@py-GY and Mo@py-GY SACs is demonstrated to ensure their feasibility in real experimental conditions. Furthermore, electronic properties are also examined in detail to analyze activity origin. This work not only provides an effective and reliable method for screening electrochemical NRR catalysts with excellent performance but also provides guidance for the rational design of SACs.