نتایج جستجو برای: catalytic effect
تعداد نتایج: 1710805 فیلتر نتایج به سال:
Titanium dioxide has been widely used for photo-catalytic and self-cleaning activities. In this study, TiO2 /SiO2 /Co nanocomposite was prepared by sol-gel method in the presence of Polyvinyl Pyrrolidone (PVP), and Hydroxyl Propyl Cellulose (HPC) as additives, and characterized by IR spectra, Scanning Electron Microscopy (SEM), Energy Dispersive Analytical X-Ray (EDAX), and X-Ray Diffraction (X...
introduction: dye removal from industrial wastewater has been considered as one of the most environmental issues. recently, new methods of treatment such as catalytic ozonation have been used to increase dye removal efficiency. so, the efficiency of catalytic ozonation by copper coated zeolite as a catalyst in the removal of reactive red 198 was investigated. materials & methods: in order to re...
this study describes a new simple, sensitive and selective catalytic kinetic spectrophotometricmethod for the determination of vanadium (v). the method is based upon the catalytic effect ofvanadium (v) on the oxidation of carminic acid by bromate in sulfuric acid media. the reaction wasfollowed spectrophotometrically by measuring the decrease in absorbance at 490 nm and thedependence of sensiti...
In this article, the catalytic activity of bis[2-(p-tolyliminomethyl)phenolato] copper(II) complex was studied, for the first time, in the oxidation of various primary and secondary alcohols to the corresponding aldehydes or ketones. The effect of different solvent was studied in the oxidation of benzyl alcohol and methanol was chosen as the reaction medium. Also the effect of different oxidant...
kinetic monte carlo simulation was applied to investigation of kinetics and mechanism of oxalic acid degradation by direct and heterogeneous catalytic ozonation. la-containing perovskites including lafeo3, lanio3, lacoo3 and lamno3 was studied as catalyst for oxalic acid ozonation. the reaction kinetic mechanisms of each abovementioned catalytic systems has been achieved. the rate constants val...
a catalytic spectrophotometric method for determination of ultra-trace quantities of manganese(ii) id described. the method is based on the catalytic effect of manganese(ii) on the oxidation reaction of ferroin by potassium periodate in acidic media. the reaction is monitored spectrophotometrically at 510 nm by a slope method and mn(ii) is determinable in the range of 1-1000ngml-1. the limit of...
a two-dimensional nanolayered polyoxomolybdate, [4,4´-h2bipy] [mo7o22].h2o (1), where 4,4´-bipy = 4,4´-bipyridine, was prepared and characterized by ft-ir and atomic absorption spectroscopies, transmission electron microscopy (tem), x-ray single crystal and powder diffraction (xrd), and thermogravimetric analysis. the catalytic performance of 1 was assessed in the epoxidation of some olefins em...
nano sulfated titania was tested as solid acid heterogeneous catalyst for the synthesis of 4-(trifluoromethyl) coumarin and coumarin derivatives under solvent-free condition. factorial design evidenced a positive effect of reaction temperature, amount of catalyst, and solvents. this nano-sized sulfated titania has been prepared by a sol-gel hydrothermal process. the prepared sulfated titania s...
This article presents the research results on production and performance of palladium-only catalytic converters. Monolith is used as the catalyst carrier and gamma alumina as the substrate. Dipping method is used for monolith washcoating. Palladium as the active metal is impregnated on gamma alumina using wet impregnation to produce catalyst samples. The effects of factors such as percent solid...
The catalytic effect of Zirconia Sulfuric Acid (ZrSA) nanoparticle which is synthesized from thereaction of ZrO with chlorosulfonic acid has been investigated in the synthesis oftetrahydrobenzo[a]xanthene-11-ones by one-pot three-component reaction of β-naphthol,aromatic aldehydes, and dimedone. Different reaction conditions were studied in the presence ofZrSA nanoparticle as catalyst. The resu...
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