Catalytic activity of iron-substituted polyoxotungstates in the oxidation of aromatic compounds with hydrogen peroxide

2010 ◽  
Vol 141 (11) ◽  
pp. 1223-1235 ◽  
Author(s):  
Ana C. Estrada ◽  
Mário M. Q. Simões ◽  
Isabel C. M. S. Santos ◽  
M. Graça P. M. S. Neves ◽  
José A. S. Cavaleiro ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Catalytic Activity ◽  
Aromatic Compounds

Decomposition of hydrogen peroxide on a two-component NiO-CdO catalyst and the effect of ionizing radiation on its catalytic properties

1979 ◽  
Vol 44 (4) ◽  
pp. 1015-1022 ◽  
Author(s):  
Viliam Múčka
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Peroxide ◽  
Catalytic Activity ◽  
Nickel Oxide ◽  
Catalytic Properties ◽  
Cadmium Oxide ◽  
Chemisorb Oxygen ◽  
Composition Region ◽  
Chemisorbed Oxygen ◽  
Two Component

The catalytic properties of two-component catalyst nickel oxide-cadmium oxide with the proportions of the components covering the whole composition region 0-100% were examined by studying the decomposition of hydrogen peroxide in aqueous solution on it. In the range 0-25 mol.% CdO, cadmium oxide is found to affect infavourably the ability of nickel oxide to chemisorb oxygen. The amount of the chemisorbed oxygen increases several times on gamma irradiation of the samples. The effect of cadmium oxide on the catalytic activity of the system shows up in fresh samples only indirectly via the changed amount of the oxygen chemisorbed. In older samples the initial catalytic activity of the system is changed, which can be explained based on the concept of bivalent catalytic centres in terms of the co-action of the catalytic centres of the two oxides, which are in equilibrium. The irradiation of the system under study speeds up the processes leading to the establishing of this equilibrium which is thermally very stable, and results in a substantial increase of the catalytic activity of the samples investigated.

Hydrogen peroxide decomposition on a two-component CuO-Cr2O3 catalyst

1988 ◽  
Vol 53 (8) ◽  
pp. 1636-1646 ◽  
Author(s):  
Viliam Múčka ◽  
Kamil Lang
Keyword(s):  
Hydrogen Peroxide ◽  
Catalytic Activity ◽  
Extreme Values ◽  
Catalytic Properties ◽  
Active Components ◽  
Catalytic Systems ◽  
Heterogeneous Catalytic ◽  
Peroxide Decomposition ◽  
Two Component ◽  
Catalytically Active

Some physical and catalytic properties of the two-component copper(II)oxide-chromium(III)oxide catalyst with different content of both components were studied using the decomposition of the aqueous solution of hydrogen peroxide as a testing reaction. It has been found that along to both basic components, the system under study contains also the spinel structure CuCr2O4, chromate washable by water and hexavalent ions of chromium unwashable by water. The soluble chromate is catalytically active. During the first period of the reaction the equilibrium is being established in both homogeneous and heterogeneous catalytic systems. The catalytic activity as well as the specific surface area of the washed solid is a non-monotonous function of its composition. It seems highly probable that the extreme values of both these quantities are not connected with the detected admixtures in the catalytic system. The system under study is very insensitive with regard to the applied doses of gamma radiation. Its catalytic properties are changed rather significantly after the thermal treatment and particularly after the partial reduction to low degree by hydrogen. The observed changes of the catalytic activity of the system under study are very probably in connection with the changes of the valence state of the catalytically active components of the catalyst.

Iodination of Aromatic Compounds Using Potassium Iodide and Hydrogen Peroxide

2008 ◽  
Vol 38 (22) ◽  
pp. 3894-3902 ◽  
Author(s):  
K. Suresh Kumar Reddy ◽  
N. Narender ◽  
C. N. Rohitha ◽  
S. J. Kulkarni
Keyword(s):  
Hydrogen Peroxide ◽  
Potassium Iodide ◽  
Aromatic Compounds

Titanium Dioxide-Supported Sulfonated Low Rank Coal as Catalysts in the Oxidation of Styrene with Aqueous Hydrogen Peroxide

2014 ◽  
Vol 69 (5) ◽  
Author(s):  
Mukhamad Nurhadi ◽  
Jon Efendi ◽  
Lee Siew Ling ◽  
Teuku Meurah Indra Mahlia ◽  
Ho Chin Siong ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Titanium Dioxide ◽  
Catalytic Activity ◽  
Diffuse Reflectance Spectroscopy ◽  
Low Rank ◽  
Bet Surface Area ◽  
High Catalytic Activity ◽  
Low Rank Coal ◽  
X Ray Diffraction ◽  
Aqueous Hydrogen Peroxide

Titanium dioxide supported sulfonated low rank coal catalyst possesses high catalytic activity in liquid phase oxidation of styrene with aqueous hydrogen peroxide at room temperature. The catalysts were prepared by sulfonation with concentrated sulfuric acid and impregnation of titanium dioxide (500-2500 µmol). The effect of titanium dioxide impregnation and calcinations on the catalysts were studied by X-ray diffraction, UV-vis diffuse reflectance spectroscopy, Fourier transform infrared spectroscopy, BET surface area, field emission scanning electron microscopy and hydrophobicity measurement. The catalytic activity of the catalysts in the oxidation of styrene by aqueous H2O2 without calcination increased when the amount of titanium dioxide increased. Meanwhile, the catalytic activity of the catalyst calcined at 500oC for 2 h was lower than before calcination. It is suggested that the agglomeration of titanium dioxide and hydrophobicity play important role in the catalytic activity of titanium dioxide-supported sulfonated low rank coal in the oxidation of styrene with aqueous H2O2. 

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