نتایج جستجو برای: catalyst activity

تعداد نتایج: 1169846  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه ولی عصر (عج) - رفسنجان - دانشکده علوم پایه 1388

چکیده ندارد.

2008
Kaoru MIYATA Sentaro OZAWA Tatsuya YAMAZAKI Yoshisada OGINO

The activity of a Te-MgO catalyst prepared by adsorbing Te vapor onto MgO powder was determined by dehydrogenation of indane, 9,10-dihydrophenanthrene, cumene, and p-cymene. The activity of the Te-MgO catalyst was higher than that of the MgO catalyst in most of the cases investigated. The selectivity of the former catalyst was much higher than that of the later in all cases studied. The Te-MgO ...

Journal: Nanochemistry Research 2016

Bis-(L-tyrosinato)copper(II) was reacted with 3-(chloropropyl)-trimethoxysilane functionalized silica that has infused magnetite to yield a magnetically separable catalyst in which the copper carboxylate is covalently linked to the silica matrix through the silane linkage. The immobilized catalyst has been characterized by spectroscopic studies (such as FT-IR, EPR, Magnetic Measurement...

Journal: :علوم و تکنولوژی پلیمر 0
شکوفه حکیم محمدمهدی مرتضوی لیلا مبلغ مهدی نکومنش حقیقی

full factorial experimental design (23) for the evaluation of slurry ethylene polymerization in the presence of an industrial ticl4/mgcl2 ziegler-natta catalyst was employed. the following parameters were used as independentvariables: al/ti molar ratio, reaction temperature and hydrogen partial pressure. the total polymerization pressure was 9 bar. catalyst activity, mfi (melt flow index) and m...

Journal: :iranian chemical communication 2016
razieh fazaeli zahra mohagheghian

a green, efficient and selective approach for the oxidation of sulfides to sulfoxides and sulfones with uhp at room temperature is reported. the reaction is performed in the presence of vanadia catalyst supported on mesocellular silica foam (mcf) with a v content ranging from 2% to 10% as heterogeneous and reusable catalyst. the structural and textural characterization of this catalyst were don...

In the present research, silica bonded n-propyl-1,3,5-triazine-2,4,6-triamine (SPTT) was synthesized by direct incorporation of chloropropyl groups through co-condensation of tetraethyl orthosilicate (TEOS) and 3-chloropropyl trimethoxysilane (CPTMS) and subsequent grafting the melamine onto the propyl groups via simple nucleophilic substitution reaction. The catalyst has been characterized by ...

Journal: :iranian journal of catalysis 2011
arash shokrolahi abbas zali hamid reza pouretedal

the esterification of free fatty acids (ffa) with methanol is studied using sulfonated porous carbon (spc) as catalyst. in compare to the amorphous sugar catalyst and protonated nafion, the proposed catalyst shows stability and high efficient performance in biodiesel production. the highest initial rate of oleic acid conversion is obtained at catalyst loading of 1 mmol h+ and mole ratio of meoh...

Journal: :journal of nanostructures 2012
j. safaei-ghomi s. rohani a. ziarati

cui nanoparticles as an expedient and recyclable catalyst for the synthesis of n-cyclohexyl-3-aryl-quinoxaline-2-amines in ethanol via a multi-component reaction are established. the products were separated from the catalyst simply by filtration. the catalyst could be recycled and reused for several times without noticeably decreasing the catalytic activity.

Journal: :iranian journal of catalysis 0
mona hosseini-sarvari department of chemistry, shiraz university, shiraz 71454, i.r. iran. sepideh najafvand-derikvandi department of chemistry, shiraz university, shiraz 71454, i.r. iran.

nano sulfated titania was tested as solid acid heterogeneous catalyst for the synthesis of 4-(trifluoromethyl) coumarin and coumarin derivatives under solvent-free condition. factorial design evidenced a positive effect of reaction temperature, amount of catalyst, and solvents.  this nano-sized sulfated titania has been prepared by a sol-gel hydrothermal process. the prepared sulfated titania s...

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