What it is
The authors report an Fe-N3(POx) single-atom catalyst for the electrochemical nitrate reduction reaction that breaks local symmetry to give switch-like adaptive coordination and dynamic tuning of the iron spin state. This design reaches high activity at low overpotential, with an ammonia yield rate of 21.96 g per mgFe per hour and a Faradaic efficiency of 89.8% at -0.56 V versus the reversible hydrogen electrode. In situ spectroscopy confirms coordination reorganization and an increased Fe spin state, which the authors link to stronger back-donation into nitrate-derived intermediates and faster hydrogenation.
Why it matters
Electrochemical nitrate reduction is a promising route to sustainable ammonia and to mitigating nitrogen pollution, but sluggish nitrate hydrogenation limits its efficiency, and designing active sites that adapt electronically to the multielectron reaction has been difficult. By making a single iron atom's coordination and spin state switch adaptively, this catalyst reaches high activity at low overpotential and a Faradaic efficiency of 89.8%. It offers mechanistic insight into tuning spin states to optimize ammonia production on iron-based catalysts.
Underlined numbers link to their source. Every metric and quoted figure is listed under Sources and data below.
Filed underAmmonia Synthesis and Nitrogen Reduction, Metalloenzymes and iron-sulfur proteins, Phosphorus and nutrient management