The electrochemical nitrogen reduction reaction (eNRR) provides a sustainable way to generate ammonia (NH₃) but its Faradaic efficiency (FE) is relatively low and could be further improved, especially on the highly active molybdenum carbide (Mo₂C) electrocatalyst. Our theoretical calculations suggest that unlike substitute doping model, interstitial Fe doping into Mo₂C is highly eNRR-selective due to decreasing hydrogen evolution activity and unique surface-hydrogenation mechanism on negatively charged Mo sites around Fe atoms. Inspired by this prediction, we successfully developed a novel interstitial Fe doped Mo₂C electrocatalyst by the pyrolysis of Fe-doped Mo/Zn bimetallic imidazolate frameworks (Fe-Mo/Zn BIFs) as a precursor where Fe atoms substitute Zn sites to obtain the spatial confinement effect. When evaluated in eNRR catalysis, Fe/Mo₂C catalyst therefore exhibits a much higher FE of 20.1% at -0.45 V vs. RHE (reversible hydrogen electrode), which is almost double that of pristine Mo₂C and substitute type. Moreover, the Fe/Mo₂C catalyst also exhibits high ammonia yield rate with excellent durability over the six continuous cycles.

电化学氮还原反应（eNRR）提供了一种可持续的方式来产生氨（NH ₃），但其法拉第效率（FE）相对较低，可以进一步提高，特别是在高活性碳化钼（Mo ₂ C）电催化剂上。我们的理论计算表明，与替代掺杂模型不同，由于在Fe原子周围带负电的Mo位置上析氢活性降低和独特的表面加氢机理，间隙Fe掺杂进入Mo ₂ C具有很高的eNRR选择性。受此预测的启发，我们成功开发了一种新型的填隙铁掺杂的Mo ₂通过热解Fe掺杂的Mo / Zn双金属咪唑骨架（Fe-Mo / Zn BIFs）作为前驱体的C电催化剂，其中Fe原子取代Zn位以获得空间限制效应。因此，当在eNRR催化中进行评估时，Fe / Mo ₂ C催化剂在-0.45 V时的RFE（可逆氢电极）为20.1％，远高于原始Mo ₂ C和替代品类型的两倍。而且，Fe / Mo ₂ C催化剂在六个连续循环中还表现出高的氨产率和优异的耐久性。