Catalytic activity of a zirconium(IV) oxide surface supported with transition metal ions

The kinetics of H2O2 decomposition have been investigated using ZrO2 suppor ted with transition metal ions including Cu-II, Ag-I, Hg-II, Co-II, Mn-II, Ni-II and Fe-III. At pH = 6.8, the reaction rate exhibits a first order dep endence on the initial H2O2 concentration at low concentrations. The order of activity of the different catalysts is strongly dependent on the [H2O2]( 0) used. The reaction proceed via the formation of the peroxo-intermediate which has an inhibiting effect on the reaction rate. The rate increases wit h increasing pH, and attains a limiting rate at higher pH's. A reaction mec hanism is proposed involving liberation of HO2. radicals from the peroxo-in termediate as the rate-determining step.