Novel magneto-electrocatalyst Cr2CO2-MXene for boosting nitrogen reduction to ammonia

Abstract

Ammonia (NH₃) plays important roles in chemistry, the environment, and energy; however, the synthesis of NH₃ relies heavily on the Haber–Bosch process, causing serious environmental pollution and energy consumption. A clean and effective strategy for the synthesis of NH₃ involves nitrogen (N₂) being transformed to ammonia (NH₃) using electrocatalysis. Adjusting the magnetism of electrocatalysts may improve their performance, and therefore, four magnetic states, nonmagnetic (NM), ferromagnetic (FM), interlayer antiferromagnetic (Inter-AFM), and intra-layer antiferromagnetic (Intra-AFM) Cr₂CO₂-MXene were designed to explore magnetoelectrocatalysis performance using well-defined density functional theory (DFT) calculations in this study. Upon comparing the nitrogen reduction limiting potentials of N₂ molecules on the surface of the four different magnetic states in Cr₂CO₂-MXene, and the selectivity calculations of the hydrogen evolution reaction (HER) and nitrogen reduction reaction (NRR), the Inter-AFM Cr₂CO₂-MXene is shown to be a better NRR electrocatalyst than the other three cases. This study paves way to unravel the mystery of the spin-catalytic mechanism and will lay a solid foundation for eNRR electrocatalysts with magnetic materials for environmental and energy applications.