Single transition atom-doped antimonene as a highly efficient electrocatalyst for the nitrogen reduction reaction: a DFT study

Abstract

The synthesis of ammonia (NH₃) through the electrocatalytic nitrogen reduction reaction (NRR) at ambient temperature and pressure provides a green low-carbon synthetic route for ammonia production. The rational design and optimization of low-cost and high-efficiency NRR electrocatalysts is a fascinating and challenging topic in chemistry. In this study, using first-principles calculations based on density functional theory (DFT), the electrocatalytic performance for the NRR of a series of single transition metal (TM) atoms doped on defective antimonene monolayer (SbML) was systematically explored. It was found that Mo@SbML exhibits the best catalytic activity for the NRR with a limiting potential of −0.34 V along the enzymatic pathway, which is due to the interaction between the empty d-orbitals of the TM and the lone pair electrons of N₂ molecules. Meanwhile, our computational results show that Mo@SbML also has high selectivity and stability. In addition, to further investigate the origin of effective NRR activities, the Bader charge, the electronic properties, the crystal orbital Hamilton population (COHP), the charge difference density (CDD) and the partial density of states (PDOS) were discussed and analyzed concretely. This work not only shows that SbML could be a promising anchor material for the NRR, but also provides useful clues for the development of novel electrocatalysts with high activity and stability.