4490

4224

كارشناسي ارشد

شيمي آلي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده شيمي

1387

[ده]، 57،[II] ص: جدول، نمودار

ص.ع. به انگليسي و فارسي

مهران غياثي

ثريا مقدادي

29/2/1388

شادپور ملك پور،امير عبدالملكي

شيمي

ID4224

به فارسي وانگليسي: نسخه قابل رويت درنسخه ديجيتال

Synthesis and characterization of a new catalyst modified SiO2 Al2O3 Mixed oxide and using it in epoxidation of cycloalkenes Zahra Salimi zsalimi84@yahoo com 2009 09 03 Department of Chemistry Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiMehran Ghiaci mghiaci@cc iut ac irAbstract Alkene epoxidation is a very useful reaction in industrial organic synthesis Epoxides are key rawmaterials for a wide variety of products and much effort is devoted to the development of new active andselective epoxidation catalysts for processes that avoid the formation of large amounts of by products Therehas been an increasing interest over the last years for the development of heterogeneous catalysts foroxidation reactions in the liquid phase with aqueous H2O2 or organic hydroperoxides This was partiallyachieved by using transition metal containing zeolites or aluminophosphates which proved to be remarkablecatalysts for the oxidation of a large family of small organic molecules with both H2O2 and tert butylhydroperoxide TBHP However as far as microporous molecular sieves are concerned reactions are limitedto substrates capable of entering the zeolite pores with a kinetic diameter smaller than 7A Moreover thesematerials are often expensive and relatively difficult to synthesize as their preparation requires specificconditions to prevent the formation of metal oxide species during the crystallization process The activity ofthese catalysts in oxidation reactions has been attributed to the presence of isolated metal sites in a silica oraluminophosphate framework Because of these limitations due to the presence of micropores many attemptshave been made to replace these zeolite based catalysts by systems containing highly dispersed transitionmetal cations on various organic or inorganic supports with high surface areas In this work we haveinvestigated the catalytic activity of the new synthesized catalyst based on SiO2 Al2O3 mixed oxid in somecycloalkene epoxidation SiO2 Al2O3 was prepared by a sol gel method with a 1 1 molar ratio of Si in to Al After this DCDMS was added to the mixed oxide and THF as a solvent In the next stage PHTBB was addeddropwise to modified it on the mixed oxide and we used DETA for synthesis a Schiff base and for completethe systhesis of ligand we added SA to the solution We have investigated all of this stages with FTIR andUV spectra For synthesis a new catalyst to cycloalkene epoxidation we mixed the sysnthesized ligand andCo CH3COO 2 4H20 in methanol as a solvent The sol was stirred for 24h at room temperature We alsosysnthesized a Mn complex at the same methode The surface area porevolume and poresize distributionwere carried out bye BET method The catalytic studies were carried out using cyclohexene pinen andcyclooctene as the substrate and TBHP as a oxidant The reaction mixture was stirred at reflax temperaturefor 24h in cyclohexan as a solvent The catalyst was separated and products were identified by GC Mass Key Words Mn III complexes epoxidation Schiff base heterogeneous catalyst

مهران غياثي

ثريا مقدادي

شادپور ملك پور،امير عبدالملكي