Triggering Heteroatom Ensemble Effect over RuFe Alloy to Promote Nitrogen Chemisorption for Efficient Ammonia Electrosynthesis at Ambient Conditions

Ammonia (NH₃) electrosynthesis from nitrogen (N₂) provides a promising strategy for carbon neutrality, circumventing the energy-intensive and carbon-emitting Haber-Bosch process. However, the current system still presents unsatisfactory performance, and the bottleneck lies in the rational synthesis of catalytic centers with efficient N₂ chemisorption ability. Herein, a heteroatom ensemble effect is deliberately triggered over RuFe alloy with spatial proximity of metal sites to promote electrocatalytic nitrogen reduction. The heteronuclear RuFe ensemble with increased surface polarization and modulated electronic structure offers the feasibility to optimize the adsorption configuration of electroactive substances and facilitate chemical bond scission. The promotion of N₂ chemisorption and the following hydrogenation are demonstrated by the in situ Fourier transform infrared spectroscopy characterizations. The catalyst thus permits significantly enhanced conversion of N₂ to NH₃ in a 0.1 M HCl environment, with a maximum ammonia yield rate of 75.45 μg h^-1 mg^-1 and a high Faradaic efficiency of 35.49%.