A single transition metal atom anchored on Nb2C as an electrocatalyst for the nitrogen reduction reaction

Abstract

Nitrogen (N₂) reduction to produce ammonia (NH₃) under milder conditions is attractive as NH₃ has been widely used in various fields. The electrocatalytic nitrogen reduction reaction (NRR) is considered to be a more moderate and green method for ammonia synthesis. Herein, using density functional theory (DFT) computations, we investigated the potential application of single-atom catalysts (SACs) toward the NRR, in which transition metal (TM, TM = Ti, V, Mn, Fe, Co, Y, Zr, Mo) atoms are supported on Nb₂C (TM-Nb₂C). Through our screening, Fe-Nb₂C is highlighted from 8 candidate systems as the superior SAC for the NRR with a low limiting potential of −0.47 V. Meanwhile, a volcano plot between U_L (NRR) and the ICOHP values of the N–H bond in *NH₂ is established to determine the optimal ICOHP values that can be used as a simple descriptor of the NRR performance of Fe-Nb₂C.