توصيفگر ها :
كاتاليست ناهمگن , هتروپلي اسيد , فسفوتنگستيك اسيد , اكسيد كبالت , اكسيد منگنز , دي اكسيد تيتانيوم , اكسايش ارتو زايلن , فتالئيك انيدريد , فاز گازي , اكسايش سيكلوهگزن , فاز مايع , اكسيدگرافن سولفونه شده , استري كردن بنزآلدهيد , متيل بنزوات
چكيده انگليسي :
101Nano heterogeneous catalyst based on phosphotungstic acid immobilizedon titanium dioxide and sulfonated graphene oxide and investigation ofo xylene and cyclohexene oxidation reactions and oxidative esterification of benzaldehyde Kianoosh Masoomi k masoomi@ch iut ac ir Department of chemistry Isfahan University of Technology Isfahan 84156 83111 Iran Supervisor Prof M Ghiaci mghiaci@cc iut ac ir June 2018Degree M Sc Language PersianAbstract This study is consist of three parts In the first part the vapor phase oxidation of o xylene tophthalic anhydride over Co Mn H3PW12O40@TiO2 catalyst under solvent free condition and usingmolecular oxygen as a green oxidizing agent was investigated The resulting solid catalysts werecharacterized by FTIR XRD XPS FESEM EDX TEM DR UV BET TGA and ICP OEStechniques The reaction conditions for oxidation of o xylene were optimized by varying thetemperature weight hourly space velocity and oxygen flow rate and a maximum of 88 2 conversion and 75 5 selectivity to phthalic anhydride was achieved with the fresh catalyst Moreover reusability of the catalyst was studied and catalytic activity remained unchanged after atleast five cycles In the second part the high efficiency oxidation of cyclohexene catalyzed byphosphotungstic acid immobilized on sulfonated graphene oxide HPW@GO SO3H undersolvent free condition and using molecular oxygen as an oxidizing agent was investigated Thecatalyst was characterized by FTIR DR UV ICP OES FESEM EDX XPS XRD TGA BET CHNS and Raman techniques In order to obtain maximum conversion of cyclohexene the reactionparameters like temperature reaction time oxygen pressure and amount of catalyst wereoptimized Also the effect of HPW loading on GO SO3H in cyclohexene oxidation wasinvestigated and under the optimized conditions a maximum of 92 cyclohexene conversion and85 selectivity to the main product was achieved with fresh catalyst Moreover the catalyst wasshown to be very stable by the reusability study up to 7 times In the third part the methylbenzoate was produced over HPW@GO SO3H catalyst by oxidative esterification ofbenzaldehyde In order to obtain maximum conversion of benzaldehyde the reaction parameterslike temperature reaction time amount of catalyst molar ratio of oxidant to benzaldehyde wereoptimized and under the optimized conditions a maximum of 96 benzaldehyde conversion and92 selectivity to the methyl benzoate was achieved with fresh catalyst Moreover the reusabilityof catalyst on the selectivity of methyl benzoate was studied and the catalytic activity remained at asatisfactory state after at least five cycles Keywords Vapor phase oxidation o Xylene Phthalic anhydride Liquid phase oxidation Cyclohexene Phosphotungstic acid Titanium dioxide Sulfonated graphene oxide molecularOxygen Solvent free condition Oxidative esterification Benzaldehyde Methyl benzoate