نتایج جستجو برای: nano catalyst
تعداد نتایج: 93226 فیلتر نتایج به سال:
Supported olefin polymerization catalysts can prevent reactor-fouling problems and produce uniform polymer particles. Constrained geometry complexes (CGCs) have less sterically hindered active sites than bis-cyclopentadienyl metallocene catalysts. In the literature, micrometer-sized silica particles were used for supporting CGC catalysts, which might have strong mass transfer limitations. This ...
3,3,6,6-Tetramethyl-9-phenyl-3,4,6,7,9,10-hexahydroacridine-1,8-(2H,5H)-dione derivatives are synthesized by nano titanium dioxide as an efficient and reusable heterogeneous nano catalyst in a one pot multi component reaction. Easy preparation and separation of catalyst, simply workup procedure, clean reaction and reusability of the catalyst up to 7 times without appreciable loss of its catalyt...
The Nano-CrY zeolite synthesized and characterized by Fourier transfer infrared (FT-IR), X-ray diffraction (XRD),and Scanning electron microscopy (SEM).The result show that nano catalyst prepared with mainly particles size about 30-80 nm .The XRD show the structure of the zeolite does not collapse. This Nano-CrY zeolite has been used as new, and nontoxic catalyst for catalyzes of synthesis of 2...
The Nano-CrY zeolite synthesized and characterized by Fourier transfer infrared (FT-IR), X-ray diffraction (XRD),and Scanning electron microscopy (SEM).The result show that nano catalyst prepared with mainly particles size about 30-80 nm .The XRD show the structure of the zeolite does not collapse. This Nano-CrY zeolite has been used as new, and nontoxic catalyst for catalyzes of synthesis of 2...
nano-silica supported boron trifluoride (bf3.sio2) is an efficient, reusable and eco-friendly catalyst for chemoselective thioacetalization of aldehydes and ketones. so, this catalyst was applied for transthioacetalization of acetals and acylals into their corresponding 1,3-dithiolanes or 1,3-dithianes in good to excellent yields. the reactions were carried out at room temperature under solven...
nano zno/ montmorillonite composite were prepared by sol gel method under ultrasonic irradiation from directly mixing montmorillonite nano clay into zinc gel. the zn(ch3coo)2.2h2o and montmorillonite nano clay was used as precursor. the zinc acetate was dissolved in di water and, nh3 (aq) solution was dropped into the zinc solution until ph 9 consequently the zinc gel was produced. the montmori...
one distinct concentration of copper ions was embedded into the silica matrix to xerogel form using copper source cu(no3)2∙3h2o. the xerogel samples were prepared with using hydrolysis and condensation reactions of tetraethyl ortho-silicate (teos) by the sol-gel method. in this investigation, new molar ratio of h2o/teos was determined to be 11.7. also, the necessary amount of tri-hydrated coppe...
a convenient and efficient one-pot four-component synthesis of 1, 2, 4, 5-tetrasubstituted imidazoles using nano tio2 as a recyclable catalyst is reported. the results show that the methodology has several advantages such as low loading of catalyst, excellent yield, short reaction time, operational simplicity and solvent-free conditions.
TiCl4/nano-cellulose as a biodegradable and eco-friendly Lewis acid catalyst was synthesized via reaction of nano-cellulose and TiCl4. This catalyst was characterized and used for synthesis of asymmetric highly functionalized tetrahydropyridines via a five-component condensation reaction of p-substituted anilines, aldehydes and ethyl acetoacetate under solvent-free condition. Simple methodology...
A highly efficient and general method for the synthesis of aryloylamido coumarinsderivatives by a three-component condensation of 4-hydroxycoumarin or 4-hydroxy-6-methylpyran-1-one, aryl glyoxals and benzamide in the presence of nano silica supported tin(II) chloride as a heterogeneous catalyst is established. In this method, SnCl2/nano SiO2 wasused as green and reusable catalyst. Excellent yie...
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