The　pursuit　of　green　ammonia　synthesis　via　electrocatalytic　nitrogen　reduction　(NRR)　faces　challenges　in　developing　high-performance,　selective　electrocatalysts.　Inspired　by　the　nitrogenase　Fe-Mo　cofactor,　this　study　explores　the　catalytic　efficiency　of　Mo　clusters　anchored　on　Fe5C2　for　NRR.　We　investigate　structural　stability,　N2　adsorption,　and　Gibbs　free　energy,　revealing　that　Mon　clusters　on　Fe5C2　demonstrate　robust　NRR　selectivity　and　notable　catalytic　activity.　Each　of　the　three　cluster　structures　demonstrated　superior　adsorption　capacity　in　the　“side-on”　configuration.　Among　the　studied　cluster　configurations,　the　Mo5-Fe5C2　shows　the　lowest　limiting　potential　(-0.24　V),　and　the　Mo4-Fe5C2　exhibits　heightened　selectivity　for　NRR,　minimizing　interference　from　the　hydrogen　evolution　reaction　(HER).　This　enhanced　performance　is　attributed　to　the　unique　structure　and　interactive　dynamics　of　Mon-Fe5C2　and　the　electron　orbital　interactions　facilitating　direct　nitrogen　charge　transfer.　Our　findings　underscore　the　potential　of　Mo　cluster-modified　Fe5C2　as　a　pioneering　catalyst　for　electrocatalytic　nitrogen　reduction.　©　2024　Elsevier　Ltd