ChemInform Abstract: Catalytic Activity of γ-Irradiated Transition Metal Ions in the Decomposition of Hydrogen Peroxide.

ChemInform ◽  
1989 ◽  
Vol 20 (1) ◽  
Author(s):  
H. J. ARNIKAR ◽  
A. H. KAPADI ◽  
A. S. GOHAD ◽  
S. B. BHOSALE
Keyword(s):  
Hydrogen Peroxide ◽  
Catalytic Activity ◽  
Transition Metal ◽  
Metal Ions ◽  
Transition Metal Ions

The effect of partial exchange of sulphonated macroporous styrene-divinylbenzene copolymers for different ions on their catalytic activity

1981 ◽  
Vol 46 (10) ◽  
pp. 2354-2363 ◽  
Author(s):  
Svatomír Kmošták ◽  
Karel Setínek
Keyword(s):  
Catalytic Activity ◽  
Transition Metal ◽  
Metal Ions ◽  
Gas Phase ◽  
Transition Metal Ions ◽  
Exchange Capacity ◽  
Total Exchange Capacity ◽  
Styrene Divinylbenzene ◽  
Na Ions ◽  
Type Of Transition

The catalytic activity of sulphonated macroporous styrene-divinylbenzene copolymers, the exchange capacity of which was neutralized from 30, 50 and 80% by Fe(III) ions and from 30% by Na ions and that of Wofatit Y-37 ion exchanger neutralized from 10% of its total exchange capacity by several transition metal ions and by sodium has been studied in isomerisation of cyclohexene and dehydration of 1-propanol in the gas phase at 130 °C. It was demonstrated that in both reactions transition metal ions exhibit additional effect to the expected neutralization of the polymer acid groups. In the case of cyclohexene isomerization, this effect depends on the degree of crosslinking of polymer mass of the catalyst. Such dependence has not been, however, observed in dehydration of 1-propanol. The type of transition metal ions did not exhibit any significant effect on the catalytic activity of the polymer catalysts studied.

Efficient Catalytic Activity of Transition Metal Ions in Vilsmeier-Haack Reactions with Acetophenones

2013 ◽  
Vol 45 (11) ◽  
pp. 721-733 ◽  
Author(s):  
F. Aneesa ◽  
K. C. Rajanna ◽  
M. Venkateswarlu ◽  
K. Rajendar Reddy ◽  
Y. Arun Kumar
Keyword(s):  
Catalytic Activity ◽  
Transition Metal ◽  
Metal Ions ◽  
Transition Metal Ions

scholarly journals New Insight into the Interplay of Method of Deposition, Chemical State of Pd, Oxygen Storage Capability and Catalytic Activity of Pd-Containing Perovskite Catalysts for Combustion of Methane

Catalysts ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1399
Author(s):  
Silva Stanchovska ◽  
Georgy Ivanov ◽  
Sonya Harizanova ◽  
Krasimir Tenchev ◽  
Ekaterina Zhecheva ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Transition Metal ◽  
Metal Ions ◽  
Supported Catalysts ◽  
Transition Metal Ions ◽  
Chemical State ◽  
Oxygen Storage ◽  
Heterogeneous Model ◽  
Wet Impregnation ◽  
Insight Into

Elaboration of Pd-supported catalysts for catalytic combustion is, nowadays, considered as an imperative task to reduce the emissions of methane. This study provides new insight into the method of deposition, chemical state of Pd and oxygen storage capability of transition metal ions and their effects on the catalytic reactivity of supported catalysts for the combustion of methane. The catalyst with nominal composition La(Co0.8Ni0.1Fe0.1)0.85Pd0.15O3 was supported on SiO2-modified/γ-alumina using two synthetic procedures: (i) aerosol assisted chemical vapor deposition (U-AACVD) and (ii) wet impregnation (Imp). A comparative analysis shows that a higher catalytic activity is established for supported catalyst obtained by wet impregnation, where the PdO-like phase is well dispersed and the transition metal ions display a high oxygen storage capability. The reaction pathway over both catalysts proceeds most probably through Mars–van Krevelen mechanism. The supported catalysts are thermally stable when they are aged at 505 °C for 120 h in air containing 1.2 vol.% water vapor. Furthermore, the experimentally obtained data on La(Co0.8Ni0.1Fe0.1)0.85Pd0.15O3—based catalyst, supported on monolithic substrate VDM®Aluchrom Y Hf are simulated by using a two-dimensional heterogeneous model for monolithic reactor in order to predict the performance of an industrial catalytic reactor for abatement of methane emissions.

scholarly journals Effect of magnesium-salts on hydrogen peroxide bleaching of non-wood pulps

2016 ◽  
Vol 51 (4) ◽  
pp. 291-296
Author(s):  
N Das ◽  
SK Bose ◽  
D Biswas
Keyword(s):  
Hydrogen Peroxide ◽  
Transition Metal ◽  
Metal Ions ◽  
Transition Metal Ions ◽  
Peroxide Bleaching ◽  
Lower Viscosity ◽  
Pulp Viscosity ◽  
Acid Washing ◽  
Mg Addition ◽  
Wood Pulps

Transition metal ions present in pulp, cause wasteful decomposition of hydrogen peroxide, a pulp brightener, and thus significantly affect the delignification selectivity of hydrogen peroxide bleaching. The metal ions also affect the brightness and optical properties of pulp. The free radicals generated during the decomposition degrade carbohydrates resulting in lower viscosity and yield. It is reported in the literature that magnesium sulfate successfully adsorbs transition metal ions and thus decrease their activity. This study dealt with the effect of Mg salts in hydrogen peroxide bleaching of jute caddies pulp. It was observed that prior bleaching treatments like chelation and acid washing of pulp were efficient in removing transition metal ions as indicated by lower consumption of hydrogen peroxide. However EDTA chelation seemed better compared to acid washing. The inclusion of Mg salts improved pulp brightness. The pulp viscosity was the highest with 0.3% Mg addition for both treated kraft and soda-AQ pulps. Considering both pulp viscosity and pulp brightness, it appeared that a 0.3% Mg dose on EDTA chelated pulp, was enough in hydrogen peroxide bleaching of pulps obtained from jute caddies. Bangladesh J. Sci. Ind. Res. 51(4), 291-296, 2016

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