The development of efficient electrochemical ammonia synthesis requires addressing four fundamental challenges: (i) reversible Mg plating/stripping in non-aqueous electrolytes, (ii) kinetic control of nitride formation, (iii) reactor design for continuous operation, and (iv) stable proton-coupled oxidation without sacrificial donors. This work establishes magnesium as a unique mediator for nitrogen reduction, where its moderate nitride formation kinetics—characterized using in situ Raman spectroscopy—enable selective N₂ activation compared to lithium and calcium systems. Through the integration of operando FTIR, isotopic labeling, and surface analysis, Mg₃N₂ is identified as the critical intermediate, and correlations between N–H bond evolution and Faradaic efficiency are established. A novel anode design supports sustained proton generation while minimizing degradation byproducts. These findings offer new mechanistic insights into magnesium-mediated nitrogen fixation and demonstrate a scalable framework for continuous electrochemical ammonia synthesis.
