Fe₂Mo₃O₈/XC-72 electrocatalyst for enhanced electrocatalytic nitrogen reduction reaction under ambient conditions

To perform the electrochemical nitrogen reduction reaction (NRR) under milder conditions for sustainable ammonia production, electrocatalysts should exhibit high selectivity, activity, and durability. However, the key restrictions are the highly stable N≡N triple bond and the competitive hydrogen evolution reaction (HER), which make it difficult to adsorb and activate N₂ on the surface of electrocatalysts, leading to a low ammonia yield and Faraday efficiency. Inspired by the enzymatic nitrogenase process and using the Fe-Mo as the active center, here we report supported Fe₂Mo₃O₈/XC-72 as an effective and durable electrocatalyst for the NRR. Fe₂Mo₃O₈/XC-72 exhibited NRR activity with an NH₃ yield of 30.4 μg·h⁻¹·mg⁻¹ (−0.3 V) and a Faraday efficiency of 8.2% (−0.3 V). Theoretical calculations demonstrated that the electrocatalytic nitrogen fixation mechanism involved the Fe atom in the Fe₂Mo₃O₈/XC-72 electrocatalyst acting as the main active site in the enzymatic pathway (*NH₂ → *NH₃), which activated nitrogen molecules and promoted the NRR performance.