نتایج جستجو برای: silica supported hclo4

تعداد نتایج: 230206  

Elham Tahanpesar, Leila Sarami

The Pechmann condensation has been used as a simple and efficient method for the preparation of coumarin derivatives, which phenols and ethyl acetoacetate were reacted in the presence of AlCl3 supported on nano silica as an efficient catalyst at 110 oC under solvent free condition to form products with good to excellent yield (55 -90%), which are identified by spectroscopi...

A. R. Abbasi A. R. Badiei, G. Mohammadi Ziarani J. Gholami

Vanadium supported on highly ordered nanoporous silica (VOx-LUS-1) was synthesized and characterized by XRD, Nitrogen adsorption‑desorption isotherms and UV-visible spectrophotometer. Direct oxidation of benzene to phenol in liquid phase by H2O2 peroxide were examined by using various solvents (methanol, acetone, acetic acid, acetonitryl). The maximum yield (25%) and selectivity (73%) of the ph...

Journal: :Molecules 2013
Zhen-Kai Lei Li Xiao Xiao-Quan Lu He Huang Chen-Jiang Liu

An efficient and direct protocol for the preparation of amidoalkylnaphthols employing a multi-component, one-pot condensation reaction of 2-naphthol, aromatic aldehydes and acetamide or benzamide in the presence of graphite supported perchloric acid under solvent-free conditions is described. The thermal solvent-free procedure offers advantages such as simple work-up, shorter reaction times and...

Journal: :Nano letters 2017
Wei Ma Keke Hu QianJin Chen Min Zhou Michael V Mirkin Allen J Bard

The properties of nanoparticles (NPs) are determined by their size and geometric structures. A reliable determination of NP dimension is critical for understanding their physical and chemical properties, but sizing ultrasmall particles on the order of nanometer (nm) scale in the solution is still challenging. Here, we report the size measurement of PtNP at nanometer resolution by in situ scanni...

2013
Song Chen Xuetao Shi Shanmugavel Chinnathambi Hongkai Wu Nobutaka Hanagata

Silica nanotubes have been extensively applied in the biomedical field. However, very little attention has been paid to the fabrication and application of micropatterned silica nanotubes. In the present study, microgrooved silica nanotube membranes were fabricated in situ by microgrooving silica-coated collagen hybrid fibril hydrogels in a Teflon microfluidic chip followed by calcination for re...

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...

Journal: :Molecules 2005
Bunjerd Jongsomjit Sutti Ngamposri Piyasan Praserthdam

Activities during ethylene/1-hexene copolymerization were found to increase using the mixed titania/silica-supported MAO with rac-Et[Ind]2ZrCl2 metallocene catalyst. Energy Dispersive X-ray spectorcopy (EDX) indicated that the titania was apparently located on the outer surface of silica and acted as a spacer to anchor MAO to the silica surface. IR spectra revealed the Si-O-Ti stretching at 980...

Journal: :Physical chemistry chemical physics : PCCP 2016
Andrew R McFarlane Hannah Geller Ian P Silverwood Richard I Cooper David J Watkin Stewart F Parker John M Winfield David Lennon

A modern industrial route for the manufacture of methyl methacrylate involves the reaction of methyl propanoate and formaldehyde over a silica-supported Cs catalyst. Although the process has been successfully commercialised, little is known about the surface interactions responsible for the forward chemistry. This work concentrates upon the interaction of methyl propanoate over a representative...

2009
A. Ueno N. Kakuta K. H. Park M. F. Finlayson A. J. Bard A. Campion M. A. Fox S. E. Webber J. M. White

The Journal of Physical Chemistry is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Silica-supported ZnS.cntdot.CdS mixed semiconductor catalysts for photogeneration of hydrogen A. Ueno, N. Kakuta, K. H. Park, M. F. Finlayson, A. J. Bard, A. Campion, M. A. Fox, S. E. Webber, and J. M. White J. Phys. Chem., 1985, 89 (18), 3828-3833 • DOI: 10.1021/j10...

2009
R. Berthoud P. Délichère D. Gajan W. Lukens K. Pelzer J.-M. Basset J.-P. Candy C. Copéret

Treatment under H2 at 300 °C of Ru(COD)(COT) dispersed on silica yields 2 nm ruthenium nanoparticles, [Rup/SiO2], according to EXAFS, HRTEM and XPS. H2 adsorption measurements on [Rup/SiO2] in the absence of O2 show that Ru particles adsorb up to ca. 2 H per surface ruthenium atoms (2H/Rus) on various samples; this technique can therefore be used to measure the dispersion of Ru particles. In co...

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