نتایج جستجو برای: catalyst activity

تعداد نتایج: 1169846  

Journal: :iranian journal of catalysis 2015
leila youseftabar-miri maryam rafieirad

the ionic liquid, n,n,n,n-tetramethylguanidiniumtriflate (tmgtf) was found to be an efficient catalyst solvent for henry reaction between nitromethane and isatin derivatives to provide 3-hydroxy-3-(nitromethyl)indolin-2-one under mild conditions. the ionic liquid amenable to successive recycling without appreciable decrease in activity. synthesized compounds have been screened for their anti-di...

A. Ziarati J. Safaei-Ghomi, S. Rohani

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.

1999
M. R. RAHIMPOUR

Frequently the activity of fresh catalyst changes with time in use. The decrease or increases of the catalyst activity with time during the course of reaction forces the system to an unsteady state operation ([1], [2], [3], [4] and [5]). One of these catalysts is the copper/zinc oxide catalyst, which is industrially used for methanol production. The activity of copper/zinc oxide catalyst declin...

Abbas Zali, Arash Shokrolahi Hamid 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 ra...

Journal: Journal of Nanoanalysis 2017
Ali Reza Kiasat Jamal Davarpanah,

In the present study, application of porous acidic catalyst functionalized with an imidazoleionic liquid ([SBA-Im]HSO4) as a phase transfer catalyst for the facile preparation of benzylthiocyanates and azides in water has been described. The catalyst has been characterized byFourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), transmissionelectron microscopy (TEM...

Journal: :Journal of the American Chemical Society 2004
Louis-Charles Campeau Mathieu Parisien Melissa Leblanc Keith Fagnou

In this Communication, we describe direct arylation reactions with improved scope and catalyst activity for the intramolecular formation of biaryl compounds. This was achieved through the establishment of a highly active and robust catalyst system and the subsequent development of a novel phosphine ligand 27. The enhanced catalytic activity extends these transformations to include previously un...

Abbas Zali, Arash Shokrolahi Hamid 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 ra...

In this study, silica nanoparticles were used as support to prepare a new heterogeneous catalyst system for application in organic reactions. The reaction of silica nanoparticles with sodium 2-bromoethane-1-sulfonate resulted in the connection of a sulfonic acid group on the surface of silica nanoparticles (NSESA). The synthetic catalyst system was characterized using different microscopic and ...

The surface of magnetite nanoparticles as nano-sized solid support was modified with a molybdenum-Schiff base complex to prepare an easily separable heterogeneous catalyst for the epoxidation of olefins. Characterization techniques such as Fourier transform infrared and inductively coupled plasma optical emission spectroscopies, X-ray diffraction, vibrating sample magnetometry, scanning, an...

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