Research progress on liquid-phase catalysis of SO2 oxidation by transition metal ions

The strong electron-accepting ability of transition metal ions enables them to catalyze the oxidation of S(IV) to S(VI) in solution. This reaction has been applied in many fields, such as flue gas desulfurization, hydrometallurgy, atmospheric chemistry, and chemical engineering. To understand the characteristics of the catalysis, this paper reviews the status of research on this reaction in the different fields. This work aims to promote the mutual appreciation of research results among different fields, and reports on the progress in studies on the reaction.