Catalytic oxidative desulfurization of a 4, 6-DMDBT containing model fuel by metal-free activated carbons: the key role of surface chemistry. Issue 24 (20th November 2019)

• Record Type: Journal Article
• Authors: Kampouraki, Zoi Christina; Giannakoudakis, Dimitrios A.; Triantafyllidis, Konstantinos S.; Deliyanni, Eleni A.
• Is Part Of: Green chemistry. Volume 21:Issue 24(2019)
• Page Start: 6685
• Page End: 6698
• Publication Date: 2019-11-20
• Subjects: Environmental chemistry -- Industrial applications -- Periodicals; Environmental management -- Periodicals; 660
• DOI: 10.1039/c9gc03234g
• Languages: English
• ISSNs: 1463-9262

Abstract

Abstract : Commercial micro/mesoporous activated carbons were utilized as metal-free catalysts for the desulfurization of a model fuel, i.e. 4, 6-dimethyldibenzothiophene (4, 6-DMDBT) in hexadecane, under ambient conditions. Oxidation of carbons led to a further catalytic improvement. Abstract : Commercial micro/mesoporous activated carbons were utilized as metal-free catalysts for the desulfurization of a model fuel, i.e. 4, 6-dimethyldibenzothiophene (4, 6-DMDBT) in hexadecane under ambient conditions. Both adsorption and catalytic oxidation were investigated as means of 4, 6-DMDBT removal. The effect of chemical modification/oxidation of the carbon surface via treatment with two different acids (HNO3 or H2 SO4 ) aiming to introduce additional functional groups was also investigated. The catalysts were characterized by FT-IR spectroscopy, N2 porosimetry, potentiometric titration, Boehm titration, and SEM-EDX, while adsorption and catalytic oxidation activity towards sufloxides and sulfones were assessed by GC-MS and UV-Vis analysis. The surface chemistry of the carbons, expressed by the density of the acidic functional groups, was found to be the most critical parameter with regard to adsorption or to catalytic oxidative performance. The surface modification of carbons by oxidation had a positive impact on the catalytic oxidation activity, leading to a 100% conversion of 4, 6-DMDBT towards the corresponding sulfoxide and sulfone, compared to 67% with the parent non-oxidized carbon. Reusability tests showed that the oxidation activity of the carbons can be maintained for at least 5 cycles.