Screening of transition metal single-atom catalysts doped on γ-graphyne-like BN sheet for efficient nitrogen reduction reaction

Ammonia is an important industrial raw material. To promote the production of ammonia, it is urgent to develop efficient catalysts for nitrogen reduction reactions (NRR). Here, we have reported a novel electrocatalyst: γ-graphyne-like BN sheet-supported single metal atom (M/γBN, M = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, and Ru) for NRR and studied the effect of Hubbard U correction in single-atom catalysts. The results of adsorption show that Ti/γBN, V/γBN, and Ru/γBN have the best adsorption energy for nitrogen. A detailed analysis of the NRR mechanism indicates that V/γBN has the lowest energy barrier in the rate-determining step when it follows a distal mechanism. Further analysis shows that the superior catalytic performance in V/γBN sheet is mainly attributed to the electron donation and back-donation mechanism. More interestingly, V/γBN greatly inhibited HER selectivity. By analyzing the doping structure and adsorption system, it can be found that when considering Hubbard U correction, there will be an obvious correlation between energy and distance. This study not only provides a basis for understanding the mechanism of nitrogen reduction reaction catalyzed by single-atom catalysts but also provides a new design idea for the rational design of high-efficiency NRR catalysts. [Display omitted] •A novel BN based single-atom catalyst, Metal/γ-graphyne-like BN as an NRR electrocatalyst.•V/γBN follows the distal mechanism with low overpotential (0.190 V) and barrier (0.412 eV).•Excellent NRR catalytic activity comes from electron donation and back - donation mechanism.