Theoretical Study on P-coordinated Metal Atoms Embedded in Arsenene for the Conversion of Nitrogen to Ammonia

The conversion of gaseous N-2 to ammonia under mild conditions by artificial methods has become one of the hot topics and challenges in the field of energy research today. Accordingly, based on density function theory calculations, we comprehensively explored the d-block of metal atoms (Ti, V, Cr, Mn, Fe, Co, Ni, Nb, Mo, Ru, Rh, W, and Pt) embedded in arsenene (Ars) for different transition systems of phosphorus (P) coordination as potential electrocatalysts for N-2 reduction reaction (NRR). By adopting a "two-step" strategy with stringent NRR catalyst screening criteria, we eventually selected Nb@P-3-Ars as a research object for a further in-depth NRR mechanism study. Our results show that Nb@P-3-Ars not only maintains the thermodynamic stability at mild temperatures but also dominates the competition with the hydrogen evolution reaction when used as the electrochemical NRR (e-NRR) catalyst. In particular, while the NRR process occurs by the distal mechanism, Nb@P-3-Ars has a low overpotential (0.36 V), which facilitates the efficient reduction of N-2. Therefore, this work predicts the possibility of Nb@P-3-Ars as an e-NRR catalyst for reducing N-2 from a theoretical perspective and provides significant insights and theoretical guidance for future experimental research.