The mechanism of nitrogen reduction reaction on defective boron nitride (BN) monolayer doped with monatomic Co, Ni, and Mo-A first principles study

In this work, transition metal atoms (TM=Co, Ni, Mo) doped with B defect (M-VB-BN) and N defect (M-VN-BN) boron nitride (BN) monolayer was constructed and used for the synthesis of ammonia with N-2 and *H as raw materials (TM=Co, Ni, Mo). Based on the density functional theory (DFT), the structure of these six modified materials was optimized, and the simulation calculation of the N-2 reduction reaction (N2RR) was carried out. It shows that the type of defects and TM will affect the reaction path. For Co-VB-BN and Ni-VB-BN, the most potential path is the alternate mechanism; Mo-VN-BN is most inclined to the enzymatic mechanism. In particular, for Co-VN-BN, Ni-VN-BN and Mo-VB-BN, the N2RR does not proceed from beginning to end according to any of the three basic mechanisms. It is manifested as a mixed mechanism in which the enzymatic mechanism and the associative mechanism are interleaved. In general, N defect is more suitable for N2RR than B defect. Among the six structures, Mo-VN-BN exhibits the highest catalytic activity, and its energy barrier for rate-determining step is only 0.24 eV. These findings can provide a certain reference for the selection of defect sites and transition metals in the study of two-dimensional BN material catalysts.

Automated summary

In this study, transition metal-doped boron nitride monolayers were used to investigate the synthesis of ammonia through N2 reduction. The type of defects and transition metals were found to impact the reaction path.