Oxidation of ferrous sulfate in acid solution by a mixture of sulfur dioxide and oxygen

Highly Efficient Photoinitiation in the Cerium(III)-Catalyzed Aqueous Autoxidation of Sulfur(IV). An Example of Comprehensive Evaluation of Photoinduced Chain Reacions

“…Catalytic autoxidation of sulfur(IV) has attracted considerable interest because of its dominant role in acid rain formation and importance in industrial desulfurization processes. − The sulfite ion−oxygen system has been used for hydroxylation, epoxidation, and oxidative cleavage of DNA. − The autoxidation of sulfite ion is also important in metallurgical technologies , and food chemistry. , Multivalent metal ions are known to be very active catalysts of this reaction, and stoichiometric, kinetic, and mechanistic aspects of several systems have been studied intensively since the 1930s. − Bäckström postulated that the formation of transition metal sulfito complexes and their decomposition are mainly responsible for the catalytic effect…”

Kinetics and mechanism of the oxidation of sulfur(iv) by iron(iii) at metal ion excess

“…1 The iron()-sulfur() reaction holds some importance in metallurgical technologies and food chemistry as well. [10][11][12] Therefore, the mechanism of the catalytic reactions with various forms of iron() is probably one of the most extensively studied area of aqueous sulfur() chemistry. 9- 35 It is understood that the catalytic effect of ferric ions mostly arises from the fact that sulfur() is rapidly oxidized by iron() and this reaction produces reactive intermediates which act as chain carriers in the autoxidation process.…”