Single-layer MoS2 with adjacent Mo sites for efficient electrocatalytic nitrogen fixation via spin-delocalized electrons effect

Electrocatalytic nitrogen fixation is crucial for sustainable NH3 production, however it still suffers from sluggish kinetics. Here, we report that single-layer MoS2 with adjacent Mo sites (A-Mo-MoS2) prepared by preciously controlling the oriented topological conversion could exhibit an exceptional NH3 yield rate of 48.8 µg h–1 mg–1 and Faradic efficiency (FE) of 27.3 % at −0.20 V vs. RHE, far beyond MoS2 with isolated sulfur vacancies (I-SV-MoS2) with a 18.8 µg h–1 mg–1 rate and 8.4 % FE. Theoretical analysis reveal that A-Mo-MoS2 could induce their unpaired spin-polarized electrons to share along the outermost Mo edge, thereby forming a grand spin-delocalized electrons reservoir. Compared to limited spin-localized electrons on I-SV-MoS2, these spin-delocalized electrons could significantly facilitate nitrogen activation and switched the rate-determining step from energy-demanding *N2 hydrogenation to surmountable *HNNH hydrogenation. Our work offers a new strategy to promote nitrogen fixation by spin-delocalized electrons effect.