Influence of H2O2 on a chloride‐dependent reaction path to chlorine dioxide

Abstract Reaction paths governing chlorine dioxide formation from solutions of sodium chlorate, sulfuric acid, hydrogen peroxide and sodium chloride at 25°C were examined. Chlorine dioxide was formed by two paths: the reduction of chlorate by hydrogen peroxide and the reduction of chlorate by chloride. At conditions of this study, the rate of the chloride‐chlorate path predominated and was enhanced by hydrogen peroxide, reaching an upper limit as hydrogen peroxide concentration was increased. A mechanism was proposed that explains the observed behavior. It is based on existing theory, but includes a new step: the rapid reaction of hydrogen peroxide with an intermediate, Cl 2 O 2 . It was shown also that chloride was not required to sustain chlorine dioxide formation in the hydrogen peroxide‐chlorate path.