Liquid-phase reactions induced by gaseous plasma. Decomposition of benzoic acids in aqueous solution

Abstract

The liquid-phase organic reactions induced by a gaseous plasma, which was generated in a localized zone between an electrolytic solution and an anode by means of contact glow discharge electrolysis (CGDE), were investigated. Benzoic acids dissolved in a neutral phosphate buffer solution were efficiently oxidized and eventually decomposed to inorganic carbon. As the intermediate products, oxalic, formic and malonic acids were detected as well as hydroxybenzoic acids. On the basis of the detailed analysis of the hydroxylation products and kinetic consideration, a reaction pathway was proposed, where the attack of hydroxyl radicals on the benzene rings of starting materials might be a key step.