Insights into the Oxidation Mechanism and Kinetics of Dimethyl Sulfoxide by Peroxymonosulfate

Dimethyl sulfone (DMSO2) plays a crucial role in human health, particularly in collagen synthesis, owing to its significant biochemical functions. Although traditional oxidation methods are effective, they present significant environmental and operational challenges that hinder their widespread application. This study systematically investigated the reaction kinetics and mechanistic pathway of dimethyl sulfoxide (DMSO) oxidation catalyzed by peroxymonosulfate (PMS) under low-temperature (0–20 °C) and nonactivated catalytic conditions. A comprehensive oxidation kinetic model was developed, and all kinetic parameters were meticulously determined. Density functional theory (DFT) calculations confirmed that the nucleophilic attack by the O–O bond in PMS on the sulfur atom of DMSO facilitates the oxidation process. Experimental and DFT-derived activation energies for the oxidation reaction were measured at 64.33 and 65.54 kJ/mol, respectively. These findings elucidate the potential mechanism of PMS-mediated oxidation of DMSO and offer a reliable reference for the safe production of DMSO2.