نتایج جستجو برای: magnetic acid catalyst

تعداد نتایج: 1108805  

Kanemite was readily prepared and used as solid base catalyst for transesterification of sunflower oil to fatty acid methyl ester (FAME). The catalyst was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), N2 adsorption-desorption and field emission scanning electron microscopy (FESEM) techniques. Central Composite Design (CCD) coupled with Response Surfac...

2014
David Greene Raquel Serrano-Garcia Joseph Govan Yurii K. Gun’ko

In this work, CoFe₂O₄@SiO₂@TiO₂ core-shell magnetic nanostructures have been prepared by coating of cobalt ferrite nanoparticles with the double SiO₂/TiO₂ layer using metallorganic precursors. The Transmission Electron Microscopy (TEM), Energy Dispersive X-Ray Analysis (EDX), Vibrational Sample Magnetometer (VSM) measurements and Raman spectroscopy results confirm the presence both of the silic...

Journal: :iranian journal of catalysis 2012
ahmad reza massah roozbeh javad kalbasi mitra toghyani

sulfonated polystyrene/montmorillonite nanocomposite (ommt/ps-so3h) was prepared and used as a novel, efficient and inexpensive heterogeneous acid catalyst in the one-pot reaction three-component mannich reaction of ketones, aromatic aldehydes and amines under solvent-free conditions. the catalyst was characterized by xrd, sem, tg, bet and ft-ir techniques. this method has advantages of high yi...

Kaolin-SO3H as a new solid acid is prepared via reaction of kaolin and chlorosulfonic acid. This natural based catalyst is very inexpensive and easy available. Imidazoles are an important class of heterocycles being the core fragment of different natural products and biological systems such as anti-allergic, anti-inflammatory, analgesic, antifungal, antimycotic, antibiotic, antiulcerative, anti...

Journal: :journal of physical & theoretical chemistry 2009
mahdi vadi najimeh astaneh

bimetallic pt-v supported by gamma-alumina is used to observe the changes of nheptanewhen passed over this catalyst. the pt concentration was kept constant at0.1wt% while the concentration of the vanadium was 0.5wt%. the activity andselectivity of catalyst have been determined under conditions at 450-500 degreescentigrade and 15-30 attn. the experimental results show that the addition of second...

Journal: :Chemical communications 2015
Yangzhi Zhu Xiangcun Li Gaohong He Xinhong Qi

Magnetic C-C@Fe3O4 hollow microspheres were prepared by using aerosol-based Fe3O4@C-SiO2 core-shell particles as templates. The magnetic double-shelled microspheres efficiently worked as carriers to load Pt nanoparticles, thus making the catalyst recyclable and reusable.

An efficient method for the synthesis of mono and bulky 1,8-dioxooctahydroxanthenes was developed by the reaction of dimedone or 1,3-cyclohexadione and aldehydes or some bisaldehydes in the presence of polyvinylpolypyrrolidone supported oxalic acid (PVPP-OXA) as a new polymeric catalyst in ethanol at room temperature. Polyvinylpolypyrrolidone supported oxalic acid was characterized by FT-IR, an...

In this study, esterification reaction of different carboxylic acids (Acetic acid, Palmitic acid, Oleic acid) with ethanol was investigated by ZnO, Al2O3-ZnO mixed oxide and phosphotungestic acid (10 %wt) immobilized on the Al2O3-ZnO mixed oxide. The heterogeneous catalysts were characterized by XRD, BET, FE-SEM and EDX techniques. Optimum yield was achieved by using 10% HPW/Al2O3-ZnO as the be...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده علوم 1390

in this thesis, a better reaction conditions for the synthesis of spirobarbiturates catalyzed by task-specific ionic liquid (2-hydroxy-n-(2-hydroxyethyl)-n,n-dimethylethanaminium formate), calcium hypochlorite ca(ocl)2 or n-bromosuccinimide (nbs) in the presence of water at room temperature by ultrasonic technique is provided. the design and synthesis of spirocycles is a challenging task becaus...

Journal: :iranian journal of catalysis 0
chandrakant bhenki department of chemistry, rajaram college, kolhapur 416004, india. shrikrishna karhale department of chemistry, rajaram college, kolhapur 416004, india. vasant helavi department of chemistry, rajaram college, kolhapur 416004, india.

a water soluble, bronsted acid, 5-sulfosalicylic acid as an efficient organocatalyst was used for the synthesis of physiologically active 2-substituted benzimidazole derivatives from o-phenylenediamine and aromatic aldehydes in ethanol at reflux condition. cost-effectiveness, use of non-hazardous solvents, metal free and commercially available catalyst, single-step, environmentally friendly gre...

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