scholarly journals The Kinetics of the Gas Phase Aldol Condensation Reaction of Propionic Acid with Formaldehyde on B2O3-P2O5-WO3/SiO2 Catalyst

2014 ◽  
Vol 8 (1) ◽  
pp. 29-34 ◽  
Author(s):  
Roman Nebesnyi ◽  
◽  
Volodymyr Ivasiv ◽  
Zorian Pikh ◽  
Viacheslav Zhyznevskyi ◽  
...  
Keyword(s):  
Gas Phase ◽  
Propionic Acid ◽  
Aldol Condensation ◽  
Condensation Reaction ◽  
Kinetics Of

scholarly journals Kinetics of aldol condensation of acetic acid with formaldehyde on B–P–V–W–OX/SiO2 catalyst

2020 ◽  
Vol 3 (2) ◽  
pp. 39-45
Author(s):  
N. S. Pavliuk ◽  
◽  
V. V. Ivasiv ◽  
O. M. Orobchuk ◽  
D. S. Shevchenko ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Chemical Composition ◽  
Acrylic Acid ◽  
Gas Phase ◽  
Silicon Oxide ◽  
Aldol Condensation ◽  
Condensation Reaction ◽  
Kinetic Equations ◽  
Stable Chemical ◽  
Kinetics Of

New catalysts B–P–V–W–Ox/SiO2 of gas-phase condensation of acetic acid from formaldehyde to acrylic acid on an industrial carrier of stable chemical composition (colloidal silicon oxide, Aerosil A-200) were synthesized. It is shown that the hydrothermal treatment of the carrier allows to increase the activity and selectivity of the catalyst in the reactions of aldol condensation of acetic acid with formaldehyde. It was found that the developed catalyst is effective in the condensation reaction of acetic acid with formaldehyde, which allows to obtain acrylic acid with a yield of 68.7% and a selectivity of 94.1%. The kinetic regularities of the reaction on this catalyst are established. According to the proposed kinetic equations, kinetic parameters are calculated that describe the condensation reaction of acetic acid with formaldehyde.

Liquid-phase aldol condensation of cyclohexanone on aluminium and iron oxides

1982 ◽  
Vol 47 (8) ◽  
pp. 2235-2245 ◽  
Author(s):  
Zdeněk Vít ◽  
Lubomír Nondek ◽  
Jaroslav Málek
Keyword(s):  
Iron Oxides ◽  
Aldol Condensation ◽  
Condensation Reaction ◽  
Complex Function ◽  
Acid Sites ◽  
Basic Site ◽  
Catalyst Poisoning ◽  
Iron Hydroxides ◽  
Transient Complex ◽  
Kinetics Of

The kinetics of the aldol condensation of cyclohexanone in decalin were investigated at 210 °C on catalysts prepared by drying and calcining the aluminium and iron hydroxides at 110-850 °C. The effect of catalyst poisoning by benzoic acid and pyridine on the course of the condensation reaction and aldol retroaldolisation was also examined. The kinetics of the cyclohexanone condensation can be described by means of Langmuir-Hinshelwood equations which are in agreement with a mechanism involving adsorption of cyclohexanone on a basic site to form a transient complex, reaction of this complex with a cyclohexanone molecule affording the aldol, the rate determining interaction of the aldol with free basic and acid sites yielding 2-(1-cyclohexen-1-yl)cyclohexanone and water and desorption of these products from the catalyst surface. The proposed kinetic model is supported by the results of catalyst poisoning. The activity of aluminium and iron oxides in the condensation of cyclohexanone is a complex function of their basicity and acidity depending strongly on the calcination temperature.

Diffusion model for deposition of epitaxial GaAs layers prepared by the MOCVD method

1991 ◽  
Vol 56 (10) ◽  
pp. 2020-2029
Author(s):  
Jindřich Leitner ◽  
Petr Voňka ◽  
Josef Stejskal ◽  
Přemysl Klíma ◽  
Rudolf Hladina
Keyword(s):  
Experimental Data ◽  
Growth Rate ◽  
Kinetic Model ◽  
Gas Phase ◽  
Substrate Surface ◽  
Deposition Process ◽  
Hydrogen Atmosphere ◽  
Epitaxial Gaas ◽  
Kinetics Of ◽  
Good Agreement

The authors proposed and treated quantitatively a kinetic model for deposition of epitaxial GaAs layers prepared by reaction of trimethylgallium with arsine in hydrogen atmosphere. The transport of gallium to the surface of the substrate is considered as the controlling process. The influence of the rate of chemical reactions in the gas phase and on the substrate surface on the kinetics of the deposition process is neglected. The calculated dependence of the growth rate of the layers on the conditions of the deposition is in a good agreement with experimental data in the temperature range from 600 to 800°C.

scholarly journals Nonanal Sensor Fabrication Using Aldol Condensation Reaction Inside Alkali-Resistant Porous Glass

2021 ◽  
pp. 1-1
Author(s):  
Masato Tsujiguchi ◽  
Takashi Aitoku ◽  
Hironori Takase ◽  
Yasuko Yamada Maru
Keyword(s):  
Porous Glass ◽  
Aldol Condensation ◽  
Condensation Reaction ◽  
Sensor Fabrication

Gas-Phase Anionic Metal Clusters are Model Systems for Surface Oxidation: Kinetics of the Reactions of Mn– with O2 (M = V, Cr, Co, Ni; n = 1–15)

2021 ◽  
Vol 125 (10) ◽  
pp. 2069-2076
Author(s):  
Brendan C. Sweeny ◽  
David C. McDonald ◽  
Nicholas S. Shuman ◽  
Albert A. Viggiano ◽  
Juergen Troe ◽  
...  
Keyword(s):  
Gas Phase ◽  
Oxidation Kinetics ◽  
Metal Clusters ◽  
Surface Oxidation ◽  
Model Systems ◽  
Kinetics Of

Theoretical study of the mechanisms for the homogenous gas-phase elimination kinetics of some 2-hydroxynitroalkanes

2006 ◽  
Vol 19 (12) ◽  
pp. 836-840 ◽  
Author(s):  
Rafael Añez ◽  
Rodolfo Izquierdo ◽  
Alba Vidal ◽  
Tania Cordova ◽  
Aníbal Sierraalta ◽  
...  
Keyword(s):  
Gas Phase ◽  
Theoretical Study ◽  
Elimination Kinetics ◽  
Kinetics Of ◽  
Phase Elimination

Gas phase interaction with catalytic oxidation reactions

1972 ◽  
Vol 326 (1565) ◽  
pp. 215-227 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Maleic Anhydride ◽  
Catalytic Oxidation ◽  
Gas Phase ◽  
Major Part ◽  
Oxidation Reactions ◽  
Mixed Gas ◽  
Kinetics Of ◽  
Oxidation Of Benzene ◽  
Homogeneous Decomposition

Studies of the catalytic oxidation of benzene to maleic anhydride and carbon dioxide over vanadia/molybdena catalysts show that the major part of the reaction involves interacting gas and gas-solid processes. The results are consistent with a mechanism in which a benzeneoxygen adduct is formed catalytically, desorbs and then reacts to give maleic anhydride entirely in the gas phase. On the basis of this proposed mechanism, the kinetics of individual reactions have been investigated in some depth. The over-oxidation of maleic anhydride has been found to be not significant under the conditions of reaction. The kinetic relationships governing the homogeneous decomposition of the adduct and the oxidation of the adduct to maleic anhydride and to carbon dioxide have been established. The results show that essentially all of the anhydride originates from mixed gas-solid/gas reaction while substantial amounts of carbon dioxide are produced entirely catalytically.

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