abstract
The tetrabutylammonium salt of phosphotungstic acid, TBA3PW(12)O(40) (PW12), has been encapsulated in the chromium terephthalate metal-organic framework MIL-101. Characterization of the composite PW12@MIL-101 by powder X-ray diffraction, FT-IR, FT-Raman and P-31 magic-angle spinning (MAS) NMR spectroscopies confirmed that the structures of MIL-101 and the polyoxometalate anion were retained after immobilization. Both PW12 and the composite material were examined as catalysts in systems for the oxidative desulfurization CODS) of model oils containing dibenzothiophene (DBT), 1-benzothiophene (1-BT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT). The ionic liquid (IL) 1-butyl-3-methylimidazolium hexafluorophosphate was employed as both extractant and reaction medium. In a one-pot operation carried out at 50 degrees C, the BT derivatives in the model oils were extracted into the IL and then oxidized (using 30% H2O2 as oxidant) to form the corresponding sulfones, resulting in a continuous decrease in the sulfur content in the oil phase. The sulfur removal from the model oil with a sulfur content (for each BT derivative) of 500 ppm reached 100% within 1 h for DBT, 100% within 3 h for 1-BT, and 99% within 4 h for 4,6-DMDBT (sulfur content, 3-7 ppm). The ODS system containing the composite PW12@MIL-101 could be recycled three times with only a slight decrease in the catalytic performance. (C) 2013 Elsevier B.V. All rights reserved.
keywords
IONIC LIQUIDS; GAS OIL; HYDROGEN-PEROXIDE; HETEROGENEOUS CATALYSTS; DEEP DESULFURIZATION; OLEFIN EPOXIDATION; BIPHASE MEDIUM; DIESEL FUEL; POLYOXOMETALATE; H2O2
subject category
Chemistry; Energy & Fuels; Engineering
authors
Ribeiro, S; Barbosa, ADS; Gomes, AC; Pillinger, M; Goncalves, IS; Cunha-Silva, L; Balula, SS
our authors
Ana Catarina Costa Gomes Alves
Assistant Researcher
Isabel Maria de Sousa Gonçalves
Associate Professor
Martyn Pillinger
Principal ResearcherProjects
acknowledgements
We are grateful to the Fundacao para a Ciencia e a Tecnologia (FCT) and COMPETE for continued support and funding through the strategic projects Pest-C/EQB/LA0006/2011 (to the Associated Laboratory REQUIMTE) and Pest-C/CTM/LA0011/2011 (to the Associated Laboratory CICECO), and the R&D projects Pl DC/EQU-EQU/121677/2010 and PTDC/CTM/100357/2008.