Chem. Sci., 2025, Accepted Manuscript DOI: 10.1039/D5SC05754J, Edge Article Xiaowei Song, Basheer Chanbasha, Jinheng Xu, Richard N. Zare We report a sustainable, air-based strategy for synthesizing ammonium nitrate (NH4NO3) by harnessing the redox-active properties of microscale air–water interfaces. The process proceeds through two sequential reactions: (1) nitrogen oxidation...