Reactions of Superoxide with Water and with Hydrogen Peroxide

Abstract

The stability of the superoxide ion, O₂-, prepared by the electric reduction of O₂ in acetonitrile, was examined. The superoxide is decomposed, dismutated, rapidly in aqueous solutions to produce O₂ and H₂O₂, and the rate depends on the water content and/or the acidity of the medium. The addition of HCl over 10^-3M significantly accelerates the dismutation, while O₂- is stabilized relatively in alkaline solutions. The addition of H₂O₂ markedly stimulated the decomposition of O₂- to form a hydroxyl radical, ·OH, which was identified by ESR spectrometry.