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.

Electrocatalytic nitrogen reduction reaction (NRR) is a sustainable approach for NH₃ production with low energy consumption. However, competing hydrogen reduction reaction (HER) in aqueous solution results in low NH₃ production and Faraday efficiency (FE). Here, MoS₂ nanostructures with a hydrophobic surface are synthesized by alkyl thiols modification. Aerophilic and hydrophobic surface facilitates an efficient three-phase contact of N₂, H₂O, and catalyst. Thus, localized concentrated N₂ molecules can overcome the mass transfer limitation of N₂ and depress the HER due to lowering the proton contacts. Although the active-sites decrease with the increase of the alkyl chain since the thiol may cover the active site, the optimized electrocatalyst achieves NH₃ yield of 12.86 × 10⁻¹¹ mol·cm⁻²·s⁻¹ at −0.25 V and 22.23% FE, which are 4.3 and 24 times higher than those of MoS₂-CP electrocatalyst, respectively. The increased catalytic performance is attributed to the high N₂ adsorption and depressed HER.

Electrochemical reduction of nitrogen to ammonia under mild conditions provides an intriguing approach for energy conversion. A grand challenge for electrochemical nitrogen reduction reaction (NRR) is to design a superior electrocatalyst to obtain high performance including high catalytic activity and selectivity. In the NRR process, the three most important steps are nitrogen adsorption, nitrogen activation, and ammonia desorption. We take MoS₂ as the research object and obtain catalysts with different electronic densities of states through the doping of Fe and V, respectively. Using a combination of experiments and theoretical calculations, it is demonstrated that V-doped MoS₂ (MoS₂-V) shows better nitrogen adsorption and activation, while Fe-doped MoS₂ (MoS₂-Fe) obtains the highest ammonia yield in experiments (20.11 µg·h^-1·mg_cat^–1.) due to its easier desorption of ammonia. Therefore, an appropriate balance between nitrogen adsorption, nitrogen activation, and ammonia desorption should be achieved to obtain highly efficient NRR electrocatalysts.