نتایج جستجو برای: magnesium catalysts formation
تعداد نتایج: 591834 فیلتر نتایج به سال:
This work reports the improved catalytic activity of nickel catalysts supported on nanocrystalline magnesium oxide prepared by a sol–gel method, using Pluronic P123 as structure-directing agent for pore formation. The presence also provided reduction crystallite size from 54 to 18 nm, well attainment small metallic particles. In situ X-ray diffraction was used assess structural evolution materi...
The interaction of the external donor (propyltrimethoxysilane - PTMS) with titanium-magnesium catalysts (TMCs) containing dibutylphthalate (DBP) as internal donor, which were prepared in different ways, was studied by chemical analysis and infrared diffuse reflectance spectroscopy (DRIFTS). The chemical composition of the catalysts after their interaction with heptane solutions of PTMS, PTMS/Al...
An aqueous ferric nitrate nonahydrate (Fe(NO3)3.9H2O) and magnesium oxide (MgO) were mixed and deposited on silicon nanowires (SiNWs), the carbon nanotubes (CNTs) formed by the concentration of Fe3O4/MgO catalysts with the mole ratio set at 0.15:9.85 and 600°C had diameter between 15.23 to 90nm with high-density distribution of CNT while those with the mole ratio set at 0.45:9.55 and 730°C had ...
Nickel compounds are recognized to cause nasal and lung cancers. Magnesium is an effective protector against nickel-induced carcinogenesis in vivo, although its mechanisms of protection remain elusive. The effects of magnesium carbonate on the cytotoxicity and genotoxicity induced by nickel subsulfide were examined with respect to the inhibition of cell proliferation, micronuclei formation, DNA...
Magnesium alkyls such as butyl octyl magnesium and ethyl are used precursors for highly active water-free chloride support materials Ziegler–Natta catalysts. These show a high viscosity in hydrocarbon solvents which negatively affect their industrial application. Density functional theory (DFT) calculations supported the hypothesis that can form oligomeric chain structures responsible viscosity...
Two new one-component aluminium-based catalysts for the reaction between epoxides and carbon dioxide have been prepared. The catalysts are composed of aluminium-salen chloride complexes with trialkylammonium groups directly attached to the aromatic rings of the salen ligand. With terminal epoxides, the catalysts induced the formation of cyclic carbonates under mild reaction conditions (25-35 °C...
Nanostructures of magnesium oxide is one of the most attractive materials which have shown various applications in many aspects of industries. So, finding a controllable and inexpensive technique to produce desirable nanostructures of MgO is valuable. In this work, magnesium oxide (MgO) with different morphologies was successfully prepared via a simple solid-state method. The molar ratio of sod...
the regioselective ring opening of styrene oxide using elemental iodine and bromine in the presence of disulfides as new catalysts was studied. the conductivity titration and uv spectroscopy were used to study the interaction of iodine with these catalysts. the results indicate that disulfide 11 is efficient in polyiodide formation, and can catalyze this reaction in excellent yield and high reg...
Novel nitrogen-doped carbon hybrid materials consisting of multiwalled nanotubes and porous graphitic layers have been produced by chemical vapor deposition over magnesium-oxide-supported metal catalysts. CN x nanotubes were grown on Co/Mo, Ni/Mo, or Fe/Mo alloy nanoparticles, and MgO grains served as a template for the porous carbon. The simultaneous formation of morphologically different carb...
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