Regulating the spin order of transition metal embedded-MXenes for boosting electrocatalytic nitrogen reduction to ammonia

Abstract

Electrocatalysis offers a promising alternative to tackle the high demand for the energy consuming and environmentally polluting Haber–Bosch process of industrial ammonia synthesis. Herein, using first-principles calculations based on density functional theory, we successfully predicted that Fe&Ni@Mo₂CS₂ diatomic catalysts have excellent electrocatalytic nitrogen reduction reaction (eNRR) performance, with a limiting potential of only −0.48 V and outstanding dynamic stability. An efficient combination of Fe in high-spin and Ni in low-spin configuration was found to promote the activation of nitrogen triple bonds and the desorption of ammonia, respectively. The mechanism of activation of the nitrogen triple bond is explained in terms of the adsorption configuration and the charge and orbital ordering variation of the nitrogen molecules.