▎ 摘　　要

The electrochemical reduction of N-2 is an important industrial process, which offers an alternative route to the Haber-Bosch procedure for NH3 production. Here, by the method of first-principles calculations, we introduce Ni-4 supported defective graphene (Ni-4-Gr) as an efficient substrate to convert N-2 into NH3. The enzymatic, alternating and distal mechanisms are investigated for N-2 reduction to explore catalytic activity of Ni-4-Gr surface. By analyzing the free energy diagrams, it is obtained that Ni-4-Gr exhibits high catalytic performance for N-2 reduction via the enzymatic pathway with an overpotential value of 0.50 V at normal temperature. (C) 2021 Elsevier Inc. All rights reserved.