MOF-74 derived FeCoS2/Fe0.95S1.05 composite nano-particles via in-situ sulfurization for highly efficient electrocatalytic nitrate reduction to ammonia

A metal-organic skeleton (MOF) -derived bimetallic sulfide catalyst, FeCoS 2 /Fe 0.95 S 1.05 , is proposed here for electrochemical ammonia production, which offers a sustainable and energy-saving technical solution for nitrate removal and green NH 3 synthesis under environmental conditions. The catalyst benefits from the excellent conductivity and effective synergistic effect of bimetallic sulfides, and it has a NH 3 yield of 2.705 mg h −1 mg cat. −1 , a maximum Faraday efficiency of 94.79%, an ammonium selectivity of 96.88%, and it also maintains good catalytic stability over 12 consecutive cycles. Theoretical and experimental results demonstrate that the incorporation of Fe into the Co site changes the electron configuration of the atoms, resulting in a more pronounced Fe-to- ⁎ NO 3 electron transfer, and NO 3 - can be effectively activated at the surface Fe-Co sites, thereby facilitating the NO 3 - RR process and realizing efficient NH 3 production. Therefore, this study provides a strategy for the design of electrochemical nitrate reduction electrocatalysts. • FeCoS 2 /Fe 0.95 S 1.05 electrocatalyst for electrocatalytic Nitrate Reduction to Ammonia. • MOF-74 derived FeCoS 2 /Fe 0.95 S 1.05 Composite Nano-particles shows large surface area. • The Fe-Co bimetallic site enhances the electrocatalytic activity. • High ammonia yield rate, faradaic efficiency and NH 3 selectivity were achieved.