Direct Oxidative Nitrogen Fixation from Air and H2O by a Water Falling Film Dielectric Barrier Discharge Reactor at Ambient Pressure and Temperature

Current industrial production of HNO3 relies on the Ostwald process via catalytic oxidation of NH3, which is responsible for the vast bulk of CO2 emission. An attractive alternative route to HNO3 is direct N-2 oxidation to aqueous HNO3, which avoids the NH3 intermediate. Herein, we for the first time report a non-thermal plasma-assisted nitrogen fixation process characteristic of a large gas-liquid contact based on the water falling film dielectric barrier discharge, wherein HNO3 is produced directly from ambient air and H2O at atmospheric pressure and room temperature without the presence of any catalytic material. By optimizing the plasma reaction conditions, a relatively high synthesis rate and low energy consumption was achieved at the same time with good product selectivity.