▎ 摘　　要

The electrochemical nitrogen reduction reaction (NRR) is considered as a promising alternative to the traditional Haber-Bosch process, but the development of a highly active and selective electrocatalyst remains a great challenge. In this research, density functional theory calculations are performed to screen a series of heteronuclear and homonuclear transition metal dimers anchored on nitrogen-doped graphene (M1M2@N6 and M1M1@N6, M-1, M-2 = Mn, Fe, Co, Ni, Mo) for NRR. Among them, heteronuclear CoMo@N6 is screened out as the most promising electrocatalyst because of its high selectivity, activity, and stability. This work not only predicts a promising electrocatalyst candidate for NRR, but also provides a useful guideline for the rational design of heteronuclear double atom catalysts.