Mechanism of bleaching by peroxides

Kinetics and mechanisms of the bleaching of methyl orange by H2O2 catalysed by MoO42− and WO42− have been studied. Bleaching arises from two parallel catalytic routes: (a) H2O2 oxidation by peroxo complexes, denoted by [O] in the diagram, and (b) singlet oxygen, 1O2, also produced by peroxo complexes.