Electrocatalytic　nitrogen　(N2)　reduction　to　ammonia　(NH3)　reaction　(eNRR)　supplies　a　promising　alternative　to　the　Haber-Bosch　technology.　However,　the　dissociation　of　N[tbnd]N　bond　hinders　its　development.　Herein,　sulfur　vacancies　are　introduced　into　FeS2　for　promoting　N2　activation　and　thus　stimulating　the　eNRR　progress.　Experimental　investigations　and　density　functional　theory　(DFT)　calculations　reveal　that　the　electrons　could　transfer　from　Fe　3d　orbits　to　N2　2π*　orbital,　thus　facilitating　the　cracking　of　inert　N2　molecules.　And　the　electron　transfer　is　easier　for　those　Fe　atoms　with　S　vacancies　in　adjacent　positions.　Furthermore,　we　find　that　eNRR　process　on　the　FeS2　surface　follows　the　distal　and　alternating　hybrid　pathway.　Also,　the　water　molecules　in　the　electrolyte　facilitate　the　first　hydrogenation　of　N2　(*N2　→　*NNH).　Notably,　FeS2　with　rich　sulfur　vacancies　exhibits　an　excellent　NH3　yield　rate　of　67.5　μg　h−1　mgcat.−1,　which　outperforms　most　of　the　reported　eNRR　activities　of　Fe-based　catalysts.　©　2024