A COMPARATIVE KINETIC STUDY OF IRIDIUM(III) CATALYSIS IN CERIUM(IV) OXIDATION OF DIOXANE IN AQUEOUS SULFURIC ACID AND PERCHLORIC ACID MEDIA

摘要: The kinetics and mechanism of IrIII-catalysed oxidation dioxane by CeIV in both aqueous H2SO4 HClO4 media have been studied at different temperatures under the conditions: [dioxane]T ≫ [CeIV]T [Ir]T (ca. 10−6–10−8moldm−3). In a slow uncatalysed path exists alongside catalysed path, while is only kinetically detectable path. media, overall process shows first-order dependence on [CeIV]T; catalytic first order exhibits non-linear [dioxane]T. probably involves pre-equilibrium interaction between catalyst substrate leading to an outer-sphere complex followed electron transfer rate-determining step involving formed steps. presumably IrIII/IrIV cycle. efficiency greater than media. Activation parameters for paths determined rationalise mechanistic