Two-Dimensional Ordered Double-Transition Metal Carbides for the Electrochemical Nitrogen Reduction Reaction

The electrochemical nitrogen reduction reaction (NRR) provides a green and sustainable strategy as an alternative to the Haber–Bosch process. The development of electrocatalysts with low overpotential, high selectivity, and fast reaction kinetics remains a significant challenge. Here, density functional theory computations are carried out to systematically predict the prospect of 18 two-dimensional (2D) ordered double-transition metal carbides (MXenes) as NRR electrocatalysts. Our results revealed that the basal plane of Mo 2 Nb 2 C 3 MXene exhibited the most outstanding catalytic activity while effectively suppressed the hydrogen evolution reaction with an overpotential of 0.48 V. The exposed Mo 3 moiety moderately regulating the electron transfer between reaction intermediates is answerable for the high activity. Finally, our finding broadens the horizon of 2D materials as NRR electrocatalysts.