نتایج جستجو برای: magnetic catalysts

تعداد نتایج: 370818  

2007
Ataullah Khan Ping Chen P. Boolchand Panagiotis G. Smirniotis

In the present study, selected metal ions (M = Cr, Mn, Co, Ni, Cu, Zn, and Ce) were introduced into iron oxide (spinel lattice) and screened for effectiveness for a high-temperature water–gas shift reaction. Simultaneous precipitation of Fe(III) nitrates along with metal nitrate(s) at optimal concentrations resulted in the formation of high-surface area nanosized catalysts. A noticeable interac...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - پژوهشکده فنی و مهندسی 1388

asymmetric polyethersulfone (pes) microfiltration flat sheet membranes were composed by the phase inversion method (pim) and were used as supports. composite membranes were fabricated by coating silicone rubber as selective layer. effect of different concentrations of pes and pdms and different solvent such as nmp, dmf and dms effects as pes solvents and support thickness and different coagulat...

2017
Nuno M. R. Martins Luísa M. D. R. S. Martins Carlos O. Amorim Vitor S. Amaral Armando J. L. Pombeiro

A series of first-row-transition-metal ferrite magnetic nanoparticles (NPs) MFe2O4 [M = Mn2+ (1), Fe2+ (2), Co2+ (3), Ni2+ (4), Cu2+ (5) or Zn2+ (6)] were prepared by the co-precipitation method and characterized by Fourier transform infrared (FTIR) spectroscopy, powder X-ray diffraction (XRD), scanning electron microscope energy dispersive X-ray spectrometry (SEM-EDS), vibrating sample magneto...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2009
ateeq rahman andreas martin kalevaru v. narayana benhard lucke

preparation of 2-chlorobenzonitrile, and benzonitrile are reported here from the corresponding 2-chlorobenzaldehyde and benzaldehyde by the reaction of ammonium hydroxide/vpo titania, vpo bulk (ammonium metavanadate) cucr catalyst/air system in methanol. all these catalysts showed better conversions with reasonable selectivity to aromatic. the results prove that bet surface area results show vp...

Journal: :polyolefins journal 2015
toshiaki funako patchanee chammingkwan toshiaki taniike minoru terano

in ziegler-natta olefin polymerization, the pore architecture of catalysts plays a crucial role in catalyticperformances and polymer properties. while the type of preparation routes (such as chemical reaction andsolution precipitation) greatly affects the catalyst pore architecture as a result of different solidification mechanisms,the modification of the pore architecture within a given route ...

2009
Nelcy D. S. Mohallem Juliana Batista da Silva

Nickel ferrites have been extensively studied due to their numerous applications in electronic devices, microwave adsorbents, corrosion protectors, magnetic fluids and catalysts [1-5], among others. Nickel ferrite is a soft material with inverted spinel with the tetrahedral site (A) occupied by Fe and the octahedral site occupied by Fe and Ni. It is applied to devices that require easy magnetiz...

Alkanedisulfamic acid functionalized silica-coated magnetic nanoparticles (ADSA-MNPs) were used as effective, low-cost and reusable solid heterogeneous nanomagnetic catalysts for conversion of aldehydes and ketones to corresponding gem-dihydroperoxides and 1,2,4,5-tetraoxanes using aqueous hydrogen peroxide (30% w/w in H2O) at room temperature. These compounds are important ...

2011
Wei Wu Xiangheng Xiao Shaofeng Zhang Feng Ren Changzhong Jiang

Many methods have been reported to improving the photocatalytic efficiency of organic pollutant and their reliable applications. In this work, we propose a facile pathway to prepare three different types of magnetic iron oxides/TiO2 hybrid nanoparticles (NPs) by seed-mediated method. The hybrid NPs are composed of spindle, hollow, and ultrafine iron oxide NPs as seeds and 3-aminopropyltriethylo...

Journal: :journal of physical & theoretical chemistry 2008
omid moradi mohammad yari s. sedaghat

in this research we used heavy propylene tetramer (hpt) and a1c13 —bf3 (lewis acids) ascatalyst and ethanol, n-propanol and n-butanol as co-catalyst. using lewis acids as catalyst, thehpts form molecules with higher molecular weight. since the raw materials of the reaction are byproducts of other reactions, are not pure and contain various compounds with different m.w andalso different chemical...

Alkanedisulfamic acid functionalized silica-coated magnetic nanoparticles (ADSA-MNPs) were used as effective, low-cost and reusable solid heterogeneous nanomagnetic catalysts for conversion of aldehydes and ketones to corresponding gem-dihydroperoxides and 1,2,4,5-tetraoxanes using aqueous hydrogen peroxide (30% w/w in H2O) at room temperature. These compounds are important ...

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