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Abstract  

The oxidation of alcohols with tert-butylhydroperoxide, in the presence of metallophthalocyanines supported on γ-alumina was investigated. These metallophthalocyanines supported on γ-alumina were effective catalysts for the oxidation of alcohols such as cyclohexanol, benzyl alcohol and hexanol.

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– 13 ] than peroxodisulfate (H 2 S 2 O 8 ). Contrary to free radical mechanisms usually exhibited in the oxidation reactions by the latter, such processes were not observed in the oxidations by the former oxidant except in radiolytic studies [ 14 , 15

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Abstract  

A kinetic model for the reaction sintering of oxide ceramics in the system Al2O3–SiO2–ZrO2 using mixtures of intermetallic compounds is presented. A 2D finite-difference model is developed to describe the exothermic gas-solid reactions taking place during the firing of ZrAl3/ZrSi2 powder compacts. The model accounts for the oxidation kinetics of the powder particles, as well as the consumption and diffusion of gaseous oxygen through the porous matrix. Additionally, possible changes in the pore structure of the green body due to the oxidation reactions and sintering effects are incorporated in the model. The resulting differential equations are coupled with a two-dimensional Fourier heat balance equation leading to a system of nonlinear partial differential equations, which is solved by the numerical method of lines. The influence of different processing parameters like sample composition and heating cycle on the reaction sintering process is investigated and the model-predicted reaction behaviour is compared to experimental results.

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Abstract  

An efficient and convenient method is reported for the selective aerobic oxidation of thiols to the corresponding disulfides using NiO/MgO/SiO2 (15 wt% NiO, Si/Mg = 3) supported cobalt(II) tetrasulfophthalocyanine as the catalyst in ethyl acetate at room temperature. The method is applicable to aromatic, aliphatic, and heterocyclic thiols. The catalyst can be recycled and reused for several times without any significant loss of its catalytic activity.

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Abstract  

The oxidation of aliphatic thiols by air oxygen under mild conditions catalyzed by copper(II) complexes with amines (e.g. benzylamine) has been investigated. It was found that the reaction proceeds as a conjugated oxidation of both amines and thiols. The products of transformation of benzylamine have been identified. Copper(I) dodecanethiolate was synthesized for the first time, and its composition was determined. The thiolate is shown to be an intermediate of the process in the systems which demonstrate low activity. The intermediate in the most active systems is a mixed-ligand copper(II) complex containing both molecules of amine and thiolate anions in the coordination sphere.

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Abstract  

The kinetics of oxidation of benzhydrols (BH) by tributylammonium chlorochromate (TriBACC) to the corresponding benzophenones have been studied. The reaction is first order each in the concentration of TriBACC, benzhydrol and H+. The oxidation of (α-C–D) benzhydrol indicates the presence of a primary kinetic isotope effect. The reaction rate have been determined at different temperatures and activation parameters calculated. With an increase in the amount of acetic acid in its aqueous mixture, the rate increases. The reaction does not induce polymerization of acrylonitrile. A mechanism involving hydride ion transfer has been proposed.

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withstand various temperatures and thermal cycling in different environments [ 5 , 6 ] and consequently, a fair knowledge on thermal stability and oxidation kinetics of various CNTs for real life applications is very important. However, limited reports are

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Abstract  

3H and 14C Measurements of the dry active waste (DAW), such as the cotton, paper, and vinyl, generated from a nuclear power plant (NPP) were conducted with wet oxidation using open vessel equipment based on simulation results. The recovery efficiency with the simulated samples was around 93% with a relative standard deviation (RSD) of 1–3%. A liquid scintillation counter (LSC) was used for counting and adjusted to a quenching correction curve. The counting value was evaluated for the minimum detectable activity (MDA), which was found to be about 4 × 10−1 Bq/g for 3H and 2 × 10−2 for 14C when approximately 5 g of the samples were measured. The measured DAW samples for the cotton, paper, and vinyl generated from NPP achieved of RSD values of 25, 25, and 60%, respectively, for 3H and 0–50% for 14C.

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Abstract  

A commercial Pd/activated carbon catalyst (10%) was treated using several redox processes: reduction with gaseous hydrogen at 140 °C, reduction by negative electrochemical polarization in acidic and basic environments, oxidation with aqueous hydrogen peroxide, and positive electrochemical polarization in acidic and basic environments. To establish the electrochemical reduction/oxidation conditions, the potentials of hydrogen and oxygen evolution at Pd/AC powder electrodes were determined from cyclic voltammetric (CV) measurements. The samples were examined for the presence of palladium oxide phases on dispersed metal particles using XRD, TPR, and TPD. The metal oxide phase disappeared following hydrogen and electrochemical reduction. Oxidative treatment of the commercial catalyst differentiated the palladium oxide layers on the metal particle surface. Changes in the surface chemistry of the Pd/PdO/AC system were confirmed by the electrochemical behavior of electrodes prepared from the carbon samples.

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Journal of Thermal Analysis and Calorimetry
Authors:
Emília Illeková
,
Jana Harnúšková
,
Roman Florek
,
František Simančík
,
Igor Maťko
, and
Jaroslava Švec Sr.

), the foamy form of Al can be produced. It is sure that the decomposition kinetics directly affects the foaming kinetics, see Fig. 1 [ 2 ]. Moreover, in the open air atmosphere, certain relation between the dehydrogenation and the oxidation of titanium

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