Single-atom transition metal supported on black phosphorene for electrochemical nitrogen reduction
Electrochemical nitrogen reduction reaction (NRR) is one of the most promising ways to produce ammonia under mild conditions. Black phosphorene (BP) has attracted wide attention as NRR electrocatalyst owing to its high Fermi level and unique electronic structure. However, the low intrinsic activity of surface sites greatly restricts its application in electrochemical NRR. In this work, we theoretically designed a series of single-atom transition metals anchored BP surface with MP3 (M = Fe, Mn, Cr, Mo, W, V and Nb) active sites for NRR via density functional theory (DFT) calculations. By taking consideration of stability, activity and selectivity, single-atom W anchored BP was screened out as a promising candidate for NRR. The energy-favorable enzymatic pathway on W@BP (W atoms adsorb on the surface of BP) and hybrid pathway on W-BP (W atoms substitute the surface P atoms of BP) have reaction onset potentials of 0.46 and 0.42 V, respectively, indicating single-atom W anchored BP has high activity toward NRR. The high performance originates from the WP3 active sites, which act as an electron adaptor to activate N2 by donating electrons, greatly regulating the charge transfer between BP and the reaction intermediates. This study proposes a promising active catalyst and provides theoretical guidance to construct BP supported transition metal single atom electrocatalysts for NRR.