نتایج جستجو برای: magnetic catalysts

تعداد نتایج: 370818  

Journal: :The Journal of organic chemistry 2008
Yu-Yun Lin Shih-Chung Tsai Shuchun Joyce Yu

The gold nanoparticles with core diameter of 3.9-4.7 nm were stabilized with octanethiolate and dipyridylphosphinicamido undecanethiolate. Without varying the size of central Au cores, palladium complexes were immobilized onto these Au nanoparticles through chelation to the surface-bound dipyridyls. Hybrid catalysts of this type were dissolvable and precipitable, and their structures and reacti...

2014
Wanlu Wang Xiang Li Zhoujun Wang Yi Tang Yahong Zhang

Experimental process The one-pot DKR of racemic 1-PE was carried out in a glass reactor with a magnetic stirring under microwave irradiation at a desired temperature. Typically, racemic 1-PE (0.10-0.4 mmol) and acyl donor (0.20-0.8 mmol) were firstly added into n-hexane (4.0 mL). And then, 20 mg of the core-shell bi-functional catalysts (Hβ-PDDA@CALB)MSs were added into the above-mentioned reac...

2014
Lianbing Ren Chao Teng Lili Zhu Jie He You Wang Xinbing Zuo Mei Hong Yong Wang Biwang Jiang Jing Zhao

Merging nanoparticles with different functions into a single microsphere can exhibit profound impact on various applications. However, retaining the unique properties of each component after integration has proven to be a significant challenge. Our previous research demonstrated a facile method to incorporate magnetic nanoparticles into porous silica microspheres. Here, we report the fabricatio...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 1991
m.m akbarnejad m. oskooie m. gharanfoli

fischer-tropsch catalysts with high activity and selectivity for olefins were produced using mordenite type sio2/al2o3= 12, 20, 28, 62 zeolite supported iron carbonyl compounds and were characterized by x-ray powder diffraction. the adsorptionof volatile fe(co)5 on the support surface was carried out under vacuum at room temperature. reduction les were monitored by vibrating sample magnetometer...

Journal: :iranian journal of catalysis 0
kaveh khosravi faculty of science, department of chemistry, arak university, arak 38156-8-8349, iran. ali reza karimi faculty of science, department of chemistry, arak university, arak 38156-8-8349, iran. shirin naserifar faculty of science, department of chemistry, arak university, arak 38156-8-8349, iran.

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 key intermediates in...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2009
sedigheh vaezifar hossein faghihian mahdi kamali

in this research na-y was synthesized by hydrothermal method and used as support for preparation of sn/pt/na-y catalysts using two different tin precursors, bu3sn(cl) and sncl2.2h2o, by sequential impregnation, in which the pt  was deposited first and in the next step sn was deposited. the catalysts were characterized by h2 chemisorption, transmission electron microscopy (tem), scanning electro...

2001
Rosa Alejandra Lukaszew Vladimir Stoica Ctirad Uher

Metal-ceramic interfaces are important in applications as diverse as magnetic storage media and supported catalysts. It is very important to understand how the crystallography and microstructure of metallic films deposited onto ceramic substrates depend on growth and/or annealing conditions so that their physical properties (e.g. magnetic, electronic, etc.) can be tailored for specific applicat...

2011
A. N. Popova

Nanoparticles of iron-cobalt have attracted great interest in recent years because of their unique physical and chemical properties because of their industrial importance in preparing magnetic recording materials, pigments, catalysts, etc. With an objective to develop magnetic materials with high saturation magnetization Fe-Co nanosysytems were synthesized by method of chemical reduction reacti...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2008
layla abadian azim malekzadeh abbas ali khodadadi yadollah mortazavi

catalysts with the formula of laco(1+x)o(3+δ), where 0 ≤ x ≤ 1, were studied for oxidation of co and c2h6 in a synthetic exhaust gas, comprising 6.0 % co and 0.2 % c2h6 in ar. ethane was selected as a model for hydrocarbons in the exhaust gas. the performance of catalysts is correlated to their properties, particularly their redox in oxidizing and reducing atmospheres. xrd patterns show perovsk...

Journal: :journal of nanostructures 0
atefeh rahmani department of chemistry, zahedan branch, islamic azad university, zahedan, iran jilla saffari department of chemistry, zahedan branch, islamic azad university, zahedan, iran

the perovskite-structured la2cuo4 nanoparticles (lco nps) have been synthesized via an ultrasonic-assisted co-precipitation route using octanoic acidas organic surfactant, and the phase composition, morphology, lattice parameters and size of nanoparticles  are characterized through fourier transform infrared spectroscopy (ft-ir), x-ray diffraction (xrd), scanning electron microscopy (sem) and t...

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