سنتز و شناسايي نانو ذرات هيبريد شده ي Co-Mn تثبيت شده بر استخوان به دو روش اسمز و تلقيح براي اكسايش پارا-زايلن ﴿p-Xylene ﴾به ترفتاليك اسيد ﴿TA﴾

چكيده انگليسي :

Synthesis and Characterization of Hybridized Nanoparticles of Co MnImmobilized on Bone by Osmosis and Impregnation Methods and its Application for Oxidation of p xylene to Terephthalic Acid Elahe Erfanmanesh Elahe erfanmanesh@yahoo com April 11 2011 Department of Chemistry Isfahan University of Technology Isfahan 84156 83111 I R Iran Degree M Sc Language Farsi Prof M Ghiaci Email mghiaci@cc iut ir Department of Chemistry Isfahan University of Technology Isfahan 84156 83111 I R Iran Abstract Nowadays most of the researches are focused on metal nano particles They have uniqueproperties on magnetic electronic optical and chemical behavior compared to bulk materials because of their large surface area to volume ratio Transition metal nano particles have thehigh catalytic activities in organic reactions But the soluble metal nano particles have someproblems such as recycling and separation of these catalysts from reactions To solve theseproblems it would be better to immobilize them on suitable support materials and use them asheterogeneous catalysts Therefore most of current researches are focused on modification ofdifferent supports for immobilization of metal nano particles However inorganic solids suchas silica carbon clay zeolites and mixed oxides are widely used to carry metal nano particles Liquid phase oxidation of methyl aromatic hydrocarbons is of great scientific technological and commercial importance In this project liquid phase oxidation of p xylene PX to terephtalic acid TA was studied with a heterogeneous catalyst immobilization ofCo2 Mn2 nano particles on bone by osmosis and impregnation methods which was promotedby KBr Also glacial acid acetic was used as solvent Purified terephthalic acid TA is an important petrochemical product and the main sourceof polyethylene terephthalate a major material for textiles and bottles About 42 million tonsof TA was produced in the world The nano catalyst was prepared from the cobalt nitrate hexahydrate Co NO3 2 6H2O and manganese nitrate hexahydrate Mn NO3 2 6 H2O which were immobilized on bone Different techniques such as UV Vis BET SEM ICP and TEM were used forcharacterization of the catalysts The catalyst showed excellent activity and selectivity For the last several years the kinetics of the reaction network and the process engineeringaspects of p xylene PX oxidation have been investigated in details The oxidation reactionsequence of p xylene PX generates three intermediates p tolualdehyde TALD p toluic acid PT and 4 carboxy benzaldehyde 4 CBA The products were analyzed by GC The free radical chain mechanism as a general framework within which the kinetics features ofhydrocarbon oxidation in liquid phase are interpreted is now generally accepted The efficacyof the Co Mn Br catalyst system is due to the synergistic effect of the coupled catalytic cyclesof cobalt manganese and bromide ions Furthermore reaction time temperature oxygen pressure catalyst concertation andpromoter concertation were optimized The maximum product TA yield was over 99 which was obtained using 0 1 g catalystCo Mn ratio 10 1 0 01 g KBr at 190 C and 17 bar The reusability of the catalyst was tested in the reaction The presence of the bone supportmakes the nano particles resistant to aggregation and precipitation and also helps preserve theircatalytic activity during the 3 cycles Keyword Catalyst Nano hybridized Co Mn Bone Osmosis Impregnation Oxidation p Xylene Terephthalic acid

عرفان منش، الهه

سنتز و شناسايي نانو ذرات هيبريد شده ي Co-Mn تثبيت شده بر استخوان به دو روش اسمز و تلقيح براي اكسايش پارا-زايلن ﴿p-Xylene ﴾به ترفتاليك اسيد ﴿TA﴾

اكسيداسيون پارا-زايلن