abstract
A composite material comprising the chromium terephthalate metal-organic framework MIL-101 and the tetrabutylammonium (TBA) salt of a zinc-substituted polyoxotungstate anion, TBA(4.2)H(0.8)[PW11Zn(H2O)O-39] ( denoted PW11Zn), has been prepared by an impregnation method and characterized by powder X-ray diffraction, scanning electron microscopy, N-2 adsorption/desorption, thermogravimetric analysis, FT-IR, FT-Raman and P-31 magic-angle spinning (MAS) NMR spectroscopies. The characterization data reveal that the polyoxometalate was homogeneously encapsulated within the cages of the support without affecting its crystalline structure and morphology. Both the homogeneous catalyst PW11Zn and the composite material PW11Zn@MIL-101 exhibit high activity in the extractive and catalytic oxidative desulfurization of a model oil containing dibenzothiophene, 1-benzothiophene and 4,6-dimethyldibenzothiophene. Complete desulfurization of the model oil could be achieved within 2 h by using the ionic liquid (IL) 1-butyl-3-methylimidazolium hexafluorophosphate as extraction solvent, aqueous 30% H2O2 as oxidant and a reaction temperature of 50 degrees C. When acetonitrile was used as extraction solvent instead of the IL, the heterogeneous catalyst PW11Zn@MIL-101 could be easily recovered and reused several times without leaching or loss of activity. (C) 2014 Elsevier B.V. All rights
keywords
METAL-ORGANIC FRAMEWORK; PHASE-TRANSFER CATALYST; OXIDATIVE DESULFURIZATION; IONIC LIQUIDS; DEEP DESULFURIZATION; MESOPOROUS SILICA; PHOSPHOTUNGSTIC ACID; SULFUR-COMPOUNDS; HYDROGEN-PEROXIDE; EFFICIENT
subject category
Chemistry; Energy & Fuels; Engineering
authors
Juliao, D; Gomes, AC; Pillinger, M; Cunha-Silva, L; de Castro, B; Goncalves, IS; Balula, SS
our authors
Ana Catarina Costa Gomes Alves
Assistant Researcher
Isabel Maria de Sousa Gonçalves
Associate Professor
Martyn Pillinger
Principal ResearcherProjects
acknowledgements
This work was partly financed by FEDER (Fundo Europeu de Desenvolvimento Regional) through COMPETE (Programa Operacional Factores de Competitividade) and by national funds through the FCT (Fundacao para a Ciencia e a Tecnologia) within the projects FCOMP-01-0124-FEDER-020658 (FCT ref. PTDC/EQU-EQU/121677/2010), FCOMP-01-0124-FEDER-013026 (FCT ref. PTDC/CTM/100357/2008), CICECO-FCOMP-01-0124-FEDER-037271 (FCT ref. PEst-C/CTM/LA0011/2013) and Requimte-FCOMP-01-0124-FEDER-037285 (FCT ref. PEst-C/EQB/La0006/2013).