Mechanism and Kinetic Model for Autocatalysis in Liquid–Liquid System: Oxidation of Dibutyl Sulfide with Aqueous Hydrogen Peroxide

Abstract

The oxidation of dibutyl sulfide with aqueous hydrogen peroxide as a liquid–liquid reaction was investigated. The autocatalysis, solubility of H2O2 in organic phase, and effects of temperature, stirring speed, initial organic DBSO concentration, and initial aqueous H2O2 concentration were studied. Solvent effect of dibutyl sulfoxide was proposed for liquid–liquid autocatalysis. The intrinsic reaction was considered as the determining step, and all the other steps were considered as equilibrium processes. Considering interfacial reaction and dynamic equilibrium of hydrogen peroxide between the two phases, the reaction was divided into exterior and interior stages. Exterior and interior mechanisms were proposed for the corresponding stages, and kinetic models were established. The parameters of kinetic model were estimated with the experimental data, and the activation energies of exterior and interior reaction were 30.62 and 73.50 kJ/mol. The validity of the kinetic models with estimated parameters was stu...