Theoretical screening of single atoms anchored on defective graphene for electrocatalytic N2 reduction reactions: a DFT study.

The reduction of molecular dinitrogen (N2) to ammonia (NH3) under mild conditions is attractive due to the wide application of ammonia. In this work, we systematically investigated a series of single metal atoms including Sc to Zn, Mo, Ru, Rh, Pd and Ag anchored on defective graphene sheets for the N2 reduction reaction (NRR) by density functional theory computations. Our calculations revealed that single Mo embedded on nitrogen doped divacancy 555-777 graphene exhibits excellent catalytic performance for the NRR, with low overpotentials of 0.32 V for MoC1N2@555-777 graphene and 0.41 V for MoN3@555-777 graphene. In particular, the removal of produced ammonia from the catalyst surface is a rapid process with a free energy change of less than 0.50 eV. Our study provides a useful guideline for further developing highly effective SACs based on defective graphene for electrochemical reduction reactions.