In Situ Exsolved FeRu Nanoparticles-Enhanced Biomimetic Electrode for Intermediate Temperature Ammonia Synthesis and Simulation.

Ammonia is an important fundamental chemical feedstock and hydrogen carrier. The conventional routes of ammonia synthesis via Haber‒Bosch process suffer from high energy consumption and substantial carbon emissions, highlighting the urgent need for an alternative technology under moderate conditions that is both efficient and sustainable. Here, the electrochemical synthesis of NH3 is demonstrated and simulated using a biomimetic electrode in a protonic ceramic electrochemical cell (PCEC). Inspired by active center structure of nitrogenase, FeMo-based electrodes are rationally designed and integrated with in situ exsolved FeRu nanoparticles, leading to significantly enhanced N2 activation and reduction kinetics. At 500 °C and 0.2 V, the electrode exhibits an excellent NH3 synthesis rate of 4.06 × 10-10 mol s-1 cm-2 and remains relatively stable over 100 h. Simulations indicate that elevated temperatures at high voltages, rather than the competing hydrogen evolution reaction (HER), may suppress NH3 synthesis. This work integrates experimental results and multiphysics simulations, offering a promising strategy for efficient NH3 production and expanding the catalytic applications of PCEC.