A DFT Study on the Mechanism of Catalytic Oxidation Desulfurization Over Ti-MWW Zeolite

• Published in: Journal of cluster science Vol. 33; no. 5; pp. 2103 - 2112
• Main Authors: Bian, He, Wang, Fang, Wu, Shuguo, Zhang, Haixia, Xu, Bin
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.09.2022; Springer Nature B.V
• Subjects: Benzothiophene; Catalysis; Catalytic oxidation; Chemistry; Chemistry and Materials Science; Desulfurizing; Dibenzothiophene; Electrons; Fossil fuels; Free energy; Heat of formation; Inorganic Chemistry; Nanochemistry; Original Paper; Oxidation; Physical Chemistry; Reaction kinetics; Room temperature; Sulfur; Zeolites; Thiophenic compound; Desulfurization; Catalytic oxidation; Ti-MWW zeolite; Mechanism
• ISSN: 1040-7278; 1572-8862
• DOI: 10.1007/s10876-021-02134-0

In this work, the oxidation mechanism of thiophenic compounds over Ti-MWW zeolite was investigated by DFT-D3 method. Formation energy and activation barrier results indicate that Ti1-η 2 –OOH–H 2 O is the most likely to be the real active center. It was revealed that the reactivity increased in the order of thiophene < benzothiophene < dibenzothiophene < 4-methyldibenzothiophene < 4, 6-dimethyldibenzothiophene, generally consistent with the previous experimental and theoretical results. Independent gradient model analysis suggests a strong interaction between O α and S in transition states, clearly explaining why the oxidation products could be formed readily. At last, the kinetics results show that oxidation desulfurization on Ti-MWW could easily occur at room temperature. The findings can contribute to a better understanding of the oxidative desulfurization mechanism of thiophenic compounds on Ti-MWW zeolite.