Title details Help Title Polyoxometalates immobilized onto mesoporous organically-modified silica aerogels for selective oxidation catalysis of anthracene / by Rami Ghassan Al-Oweini Thesis Name(s) Al-Oweini, Rami Ghassan (Main Author) American University of Beirut. Faculty of Arts and Sciences. Department of Chemistry (Related name) Publication 2009 Physical Details xviii, 188 leaves; ill. (some col.); 30 cm. Subjects Polyoxometalates Mesoporous materials Silica Catalysis Anthracene Aerogels Classmarks T:005300 Notes Dissertation: Thesis (M.S.)--American University of Beirut, Dept. of Chemistry, 2009. Dissertation: Advisor : Dr. Houssam El-Rassy, Assistant Professor, Chemistry Member of Committee : Dr. Rabih Sultan, Professor , Chemistry Member of Committee : Dr. Faraj Hasanayn, Associate Professor ,Chemistry. General: Appendices : leaves 137-169. Bib. & Index: Bibliography : leaves 170-188. Abstract Novel surface organically-modified silica aerogels were synthesized and characterized by FTIR spectroscopy and nitrogen adsorption/desorption experiments. The surface modification of the silica aerogels was conducted with the help of a two-step sol-gel process where various silicon precursors and co-precursors were used. The silicon precursors have identical methoxy and ethoxy groups, while the co-precursors have a substituted non-hydrolysable alkoxy group (methyl, ethyl, n-propyl, iso-butyl, octyl, vinyl, or phenyl) substituted instead. The functional groups that were functionalized on the surface of these silica aerogels have been identified and appealing physicochemical properties were identified. The aerogels synthesized with a very fine mesoporous nature possessed high specific surface areas and pore volumes. The analysis of the structure of these synthesized silica materials were chemically very comparable with only some differences due to the nature of the various silicon precursors. Such highly qualified mesoporous materials were used as the very suitable supports onto which two types of polyoxometalates were loaded. In this thesis, inorganic-organic hybrid silica aerogel materials were synthesized by the immobilization of two molybdovanadophosphoric acids onto the mesoporous silica aerogels synthesized through an amine organic linker. All the catalyst materials were characterized by atomic absorption spectroscopy, FTIR, nitrogen sorption measurements, XRD, and DR UV-Vis for their structural nature and physicochemical properties. These techniques revealed that the polyoxometalates were retained inside the pores of the mesoporous silica aerogels. The catalytic activities of these supported POMs on silica aerogel materials were tested in liquid-phase oxidation of anthracene with 70% tert-butylhydroperoxide as the oxidant in benzene. Immobilized molybdovanadates onto amine-functionalized silica aerogel materials was highly active in the oxidation of anthracene to 9, 10-anthraquinone, where an improvement of the catalytic activity was noticeable with 100% selectivity for 9, 10-anthraquinone. Finally, oxidant and solvent effects were evaluated and analyzed. Availability Barcode Location Shelf Shelfmark Status Category   Jafet Archives and Special Collections Thesis T:5300:c.1 ASC-Binding Building Use

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