Efficient electrocatalytic N2 fixation over BC3N2 monolayer: A computational screening of single-atom catalysts

• Single TM-atom-supported 2D BC 3 N 2 monolayer possesses outstanding nitrogen reduction reaction (NRR) catalytic activity. • V N -Nb@BC 3 N 2 was picked out benefitting from its high NRR activity (limiting potentials of 0.46 V) and high selectivity (0.56 v for HER). • The origin of NRR activity on V N -Nb@BC 3 N 2 was explained as the weakening effect of antibonding and radical-like effect of d -2 π *. The activity and selectivity of nitrogen fixation is an urgent problem to be solved in research and design of efficient electrocatalysts. In this work, we systematically researched the feasibility of a single transition metal (TM) atoms supported on graphene-like BC 3 N 2 for electrocatalytic nitrogen (N 2 ) fixation by using the density functional theory (DFT) calculations. The results shown that single TM atoms could embed on BC 3 N 2 monolayer steadily and activate nitrogen molecule efficiently to facilitate NRR process. In addition, the V N -Nb@BC 3 N 2 system exhibited excellent NRR activity due to its extremely low limiting potentials which is 0.46 V. The NRR activity of V N -Nb@BC 3 N 2 system was origin from the weakening effect of antibonding and radical-like effect of d -2 π *. The V N -Nb@BC 3 N 2 system was selected not only benefitting from its high NRR activity but also its high selectivity which the HER limiting potentials is 0.56 V. This work may serve as guidance for designing NRR catalysts and understanding the mechanism of N 2 fixation.