سنتز و شناسايي نانوذرات هيبريد شده ي Co-Mn تثبيت شده بربنتونيت اصلاح شده براي اكسايش پارازايلن ﴿p-Xylene ﴾ به ترفتاليك اسيد ﴿TA﴾

چكيده انگليسي :

Synthesis and Characterization of Hybrid Nanoparticles of Co Mn Immobilized on Bentonite and its Application for Oxidation of p Xylene to Terephthalic acid Mehdi Mostajeran mehdi iut @yahoo com March Department of Chemistry Isfahan University of Technology Isfahan I R Iran Degree M Sc Language Farsi Prof M Ghiaci Email mghiaci@cc iut ir Department of Chemistry Isfahan University of Technology Isfahan I R Iran Abstract Nowadays most of the researches are focused on metal nanoparticles 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 nanoparticles have the highcatalytic activities in organic reactions But the soluble metal nanoparticles have some problemssuch as recycling and separation of the catalysts from reactions To solve these problems it wouldbe better to immobilize them on suitable support materials and use them as heterogeneous catalysts Therefore most of current researches are focused on modification of different supports forimmobilization of metal nanoparticles However inorganic solids such as silica carbon clay zeolites and mixed oxides are widely used to carry metal nanoparticles Liquid phase oxidation ofmethyl aromatic hydrocarbons is of great scientific technological and commercial importance One of the most successful commercial applications is the production of terephthalic acid TA byliquid phase oxidation of p xylene PX with air over a Co Mn Br catalyst system in acetic acid HOAc at C As practiced this reaction is known as the MC Mid Century process Forthe last several years the kinetics of the reaction network and the process engineering aspects ofthe MC process of PX oxidation have been investigated in details The free radical chainmechanism as a general framework within which the kinetics features of hydrocarbon oxidation inliquid phase are interpreted is now generally accepted The efficacy of the Co Mn Br catalystsystem is due to the synergistic effect of the coupled catalytic cycles of cobalt manganese andbromide In this work synthesis and characterization of a new bentonite supported catalyst isreported In this regard Na bentonite was modified in two steps At the first step the Na bentonitewas modified with cetylpyridinium bromide CPB as a monolayer and then this monolayerbentonite treated with the second generation of an amidoamine cascade named dodecylazanediyl bis N dodecylazanediyl bis N aminoethyl hydroxybenzenimine ethyl propanamide DAEP for preparation of a modified bilayer bentonite Ben DAEP modified The new host guest catalyst was prepared by immobilization of Co Mn orCo Mn on the Ben DAEP modified The solid catalysts characterized by FT IR SEM BET XRD XRF TEM and CHN Reaction conditions are optimized for oxidation by varyingtemperature pressure amount of catalyst time and relation between catalyst and oxidant This isthe first report on performing this reaction with nanocatalysts The reaction did not proceed in theabsence of the catalyst The optimum conditions for this reaction are g catalyst which is w Br as promoter ocontains Co Mn C atm and h Overall conversion isand the selectivity for terephthalic acid is more than These results have shown that thisresearch is a successful attempt for oxidation of p Xylene Keyword Dendrimer Cetyl Pyridinium Bromide CPB Nano hybridized Co Mn Bentonite Hemi micelle Oxidation of p Xylene Terephthalic acid

مستاجران، مهدي

سنتز و شناسايي نانوذرات هيبريد شده ي Co-Mn تثبيت شده بربنتونيت اصلاح شده براي اكسايش پارازايلن ﴿p-Xylene ﴾ به ترفتاليك اسيد ﴿TA﴾

درخت سان , ستيل پريدينيوم برميد , همي ميسل , ترفتاليك اسيد