Recent advances in Fe, Mo-based electrocatalysts for nitrogen reduction under ambient conditions

Abstract

Electrochemical nitrogen reduction reaction (NRR) is efficient technology to replace the Haber–Bosch process to realize the transformation of N₂ to NH₃ with sustainable electricity under ambient conditions. However, the electrochemical NRR faces great challenges from problems such as low N₂ molecule dissolution in the electrolyte, strong competition reaction from hydrogen evolution reaction (HER), high energy required to break the stable NN bond, 6 proton-coupled electron transfer with high energy barriers, which leads to low NH₃ yield and Faraday Efficiency (FE_NH3), and inability to satisfy the massive demand for NH₃. Herein, we comprehensively summarize recent advances in Fe and Mo-based NRR electrocatalysts (two essential elements in biological nitrogen fixation). In detail, the NRR reaction mechanism, Fe-based catalysts, Mo-based catalysts and Fe and Mo-based catalysts are reviewed. Moreover, the influence of the morphology, chemical composition and microstructure of the electrocatalysts on their NRR properties is also discussed. Finally, the prospects of electrochemical NRR and challenges in the future are summarized.