Mimicking Enzyme Activation Within an Ionic Liquid-Immobilized Coordination Capsules for Electroreduction of N₂ to...

Electrochemical nitrogen reduction powered by renewable electricity plays a crucial role in sustainable and eco-friendly ammonia (NH₃), but current techniques were still limited by the low efficiency and selectivity for practical application. In this study, we introduce an enzyme-inspired approach that utilizes a redox-reversible helical capsule H1 to interact with the well-modified N₂-adducts for thorough electrochemical reduction of N₂ into NH₃. The strategy included the utilizing of hydroxyl groups that decorated on the capsule to encapsulate the N₂-associated ionic liquid to form a substrate-involved intermediate, anodically shifting the redox potential of the N₂ adduct. The pocket shielding approach enables the production of NH₃ at a lower applied potential (-0.08 V vs. reversible hydrogen electrode, RHE) with enzymatic kinetics, facilitating a rate of 182.5 µg·mg^-1 _cat·h^-1 and a Faradaic efficiency of 48.50%, which is comparable to that of iron-based native nitrogenase. A continuous working laboratory at 15 mA·cm^-2 yields a NH₃ turnover number (TON) of 1640 over 100 h. The new strategy of molecular electrocatalysts with an enzymatic activation manner and anodic shift of the applied potentials sheds light on the rational design of high-performance electro-catalytic technologies for nitrogen capture and conversion.