NO_<i>x</i> synthesis by atmospheric‐pressure N₂/O₂ filamentary DBD plasma over water: Physicochemical mechanisms of plasma–liquid interactions

Abstract

Abstract In this study, an atmospheric‐pressure filamentary dielectric barrier discharge plasma is produced over a deionized (DI) water surface to study the physicochemical mechanisms of plasma–liquid surface interactions for NO x synthesis. The gas‐phase plasma diagnostics are performed using optical emission spectroscopy, Fourier‐transform infrared spectroscopy, and by recording voltage–current curves, and liquid‐phase species are analyzed using ion chromatography and UV−visible spectrophotometer. The investigations indicate that the reaction pathways for reactive oxygen and nitrogen species (H 2 O 2 , , ) formation in DI water depend on different experimental conditions. It is observed that the conversion of nitrites into nitrates is significantly influenced by reactive oxygen species. The energy yield for the total amount of NO x synthesized ranges from 1.3 × 10 −4 to 3.4 × 10 −3 mol/MJ.