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

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.

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.

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