Interfacial Microextraction Boosting Nitrogen Feed for Efficient Ambient Ammonia Synthesis in Aqueous Electrolyte

Abstract The extremely low nitrogen (N₂) solubility in aqueous solution greatly limits the gas reactant supply to catalysts resulting in a bottleneck in establishing efficient electrocatalytic N₂ reduction reaction (NRR). Here, aiming at fairly few N₂ dissolving in aqueous electrolyte, an N₂‐microextractor (NME) that can extract the N₂ from water, then feed it to catalysts on electrodes, is reported. The NME consists of polymer framework and extractant that possess high solubility for N₂, which serves as an ultra‐thin interfacial system wrapping around electrodes. As expected, the enhancement of N₂ supply in NRR leads to a record‐high Faradaic efficiency (80.1%) with an ammonia yield rate of 58.3 µg h⁻¹ mg⁻¹ under ambient conditions. This is of great significance to a sustainable “Ammonia Economy.”