Investigation of 3,3′,5,5′-tetra-tert-butyl-4,4′-stilbenequinone-based catalyst in the reaction of liquid-phase oxidation of inorganic sulfides

ABSTRACT

In this paper, the intermediate and final reaction products of catalytic oxidation of inorganic sulfides in the presence of oxygen dissolved in the kerosene fraction and 3,3′,5,5′-tetra-tert-butyl-4,4′-stilbenequinone were investigated. The thiosulfate and sulfate are major products of the oxidation of sodium sulfide under these conditions. The intermediate and final products in the catalytic oxidation of sulfide sulfur do not affect the rate of its oxidation. The yield of catalytic oxidation products depends on the nature of the sulfide and on the pH of the solution. The catalytic cycle for sulfide oxidation in the presence of 3,3′,5,5′-tetra-tert-butyl-4,4′-stilbenequinone is shown. The role of 3,3′,5,5′-tetra-tert-butyl-4,4′-stilbenequinone is to create a new and a more effective way of electron transfer from the reducing agent (sulfide) to the oxidant (oxygen).

GRAPHICAL ABSTRACT

KEYWORDS:

• Inorganic sulfides
• 3,3′,5,5′-tetra-tert-butyl-4,4′-stilbenequinone
• sodium thiosulfate
• sodium sulfate
• catalytic mechanism

Acknowledgements

The authors wish to recognize the R&D Center ‘AhmadullinS – Science & Technology’ and their colleague for the technical support in experiments. We also thank the Department of Industrial Biotechnology of Kazan National Research Technological University for helpful discussions and comments on the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Hien Y. Hoang http://orcid.org/0000-0001-5069-1135