Supported Chromium Oxide Catalysts for Olefin Polymerization. VII. Kinetics of Ethylene Polymerization

1972 ◽  
Vol 6 (1) ◽  
pp. 169-176 ◽  
Author(s):  
R. Spitz
1999 ◽  
Vol 51 (2) ◽  
pp. 215-221 ◽  
Author(s):  
Bert M Weckhuysen ◽  
Robert A Schoonheydt

1992 ◽  
Vol 57 (11) ◽  
pp. 2215-2226 ◽  
Author(s):  
Daniela Gulková ◽  
Miloš Kraus

Sixteen primary alcohols of the structure RCH2OH (R = CH3, C2H5, (CH3)2CH, (CH3)3CCH2, HOCH2, CH3OCH2, C6H5, C6H5CH2, C6H5OCH2, ClCH2, BrCH2, F3C, CNCH2, (CH3)2NCH2, (C2H5)2NCH2 and tetrahydrofurfuryl) were explored for the possibility of obtaining the corresponding aldehydes by dehydrogenation on solid catalysts. Various catalysts were tested and two zinc oxide-chromium oxide catalysts were selected for further work because their activity and selectivity was satisfactory; moreover, the selectivity could be improved by addition of sodium into the catalysts and of water into the feed. The reaction was performed in the temperature range 250-450 °C and at atmospheric pressure. 2-Chloroethanol, 2-bromoethanol, ethylene glycol, 2-cyanoethanol and 2-(N,N-diethylamino)ethanol decomposed and deactivated the catalyst. The other alcohols were studied from the point of kinetics of dehydrogenation, which was described by a Langmuir-Hinshelwood type rate equation (3), and of substituent effects on rate, which were correlated by Taft equation (1) with the slope ρ = -1.46. The preparative value of catalytic dehydrogenation for obtaining substituted aldehydes was confirmed by prolonged runs and isolation of the aldehydic product by distillation using as the feeds 2-methoxyethanol and 2-(N,N-dimethylamino)ethanol, respectively.


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