Electrolytic Synthesis of Peroxyacetic Acid Using In Situ Generated Hydrogen Peroxide on Gas Diffusion Electrodes

Abstract

An electrochemical method for the preparation of peroxyacetic acid (PAA) using in situ generated hydrogen peroxide on the gas diffusion electrode (GDE) as an oxygen cathode has been described. Effects of several experimental conditions, such as current density, oxygen feed rate, electrolyte concentration, electrolytic cell configuration, flow rate of electrolyte solution, and Pt catalyst incorporated into GDE upon the cathodic reaction of oxygen to hydrogen peroxide as well as the production of PAA solution, have been investigated. Hydrogen peroxide is electrogenerated by the reduction of oxygen on the GDE and the generated hydrogen peroxide can undergo a chemical reaction with acetic acid in the presence of solid superacid, Nafion-H as a catalyst to produce PAA. It is also suggested that the formation of PAA is initiated by the active oxygen, electrogenerated on the cathode surface. The current efficiency for the production of PAA was found to be 28% at a current density of 1 A/dm2 and electrolyte flow rate of 160 mL/h. A probable reaction mechanism for the formation of PAA is proposed. © 2004 The Electrochemical Society. All rights reserved.