In situ preparation and performance of iron-based electro-magnetic synergistic electrochemical nitrogen fixation catalysts

Abstract

An iron-based catalyst was prepared in situ in FeSO₄ solution by electrochemical technology to catalyze the reduction of N₂ to NH₃. FeSO₄ solution was not only used as an electrodeposition solution for preparing the iron-based catalyst, but also as an electrolyte for catalyzing the synthesis of ammonia by the electrochemical nitrogen reduction reaction (ENRR). It was proved that the main component of the iron-based catalyst was Fe(0), and the morphology of the prepared catalyst was a lamellar structure. The ENRR performance was tested at different reaction potentials and different electrolyte concentrations, and the optimal reaction conditions were investigated. It was found for the first time that the applied magnetic field can significantly increase the current density. Thus, the yield and efficiency of electrochemical ammonia synthesis are significantly affected. When the potential was −1.0 V vs. SCE and the electrolyte was 0.3 mol L⁻¹ FeSO₄ solution, the highest ammonia yield was 923 ± 46 mg h⁻¹ m⁻² and the highest Faraday efficiency was 18.35%. This work simplifies the tedious and costly catalyst synthesis process and provides a new strategy for the industrial application of the ENRR.