Alumina: catalyst and support. XXXVII. Mechanism of dehydration of cis- and trans-2-alkyl-, 2-phenyl- and 3-tert-butylcyclohexanols over alumina catalysts

1968 ◽  
Vol 33 (5) ◽  
pp. 2035-2043 ◽  
Author(s):  
Edward J. Blanc ◽  
Herman Pines
Keyword(s):  
Alumina Catalyst ◽  
Mechanism Of Dehydration ◽  
Cis And Trans ◽  
Alumina Catalysts

Electrocatalytic hydrogenation of octyl aldehyde over Pd catalysts

2007 ◽  
Vol 85 (7-8) ◽  
pp. 475-478
Author(s):  
Ciprian M Cirtiu ◽  
Hugues Ménard
Keyword(s):  
Aqueous Ethanol ◽  
Supporting Electrolyte ◽  
Catalyst Support ◽  
Current Intensity ◽  
Electrocatalytic Hydrogenation ◽  
Alumina Catalyst ◽  
Pd Catalysts ◽  
Alumina Catalysts

The electrocatalytic hydrogenation (ECH) of octyl aldehyde (octanal) to octyl alcohol (octan-1-ol) was investigated using commercial Pd/alumina catalysts in aqueous ethanol. The influence of different parameters, such as catalyst support, current intensity, polarity of solvent, supporting electrolyte, and octanal concentration, on the electrocatalytic hydrogenation of octanal was studied.Key words: octanal, octan-1-ol, Pd/alumina catalyst, electrocatalytic hydrogenation.

Sterischer Ablauf der Dehydratisierung von gasförmigem 2-Butanol-3-d1 an AlPO4, Ba3(PO4)2 und Ca3(PO4)2 / Stereo Mechanism of Dehydration of Gaseous 2-Butanol-3-d1 over AlPO4, Ba3(PO4)2 and Ca3(PO4)2

1972 ◽  
Vol 27 (12) ◽  
pp. 1462-1464 ◽  
Author(s):  
Kurt Thomke ◽  
Heinrich Noller
Keyword(s):  
Mass Spectrometric ◽  
Temperature Range ◽  
First Case ◽  
Mechanism Of Dehydration ◽  
Leaving Groups ◽  
Cis And Trans ◽  
Mass Spectrometric Techniques ◽  
Insight Into

Dehydration can proceed according to one (E2) or two (El, ElcB) step mechanisms. In the first case the leaving groups can be abstracted from the cis or trans (syn or anti) position. In order to get insight into the mechanism, the dehydration of 1-butanol, 2-butanol, D,L-erythro- and D,L-threo-2-butanol-3-d1 as well as the isomerization of 1-butene and cis-2-butene were studied in the temperature range from 250 to 400°C, using microcatalytic and mass-spectrometric techniques. In order to distinguish between cis and trans elimination, erythro- and threo-2-butanol-3-d1 were studied. Over AlPO4, Ba3(PO4)2 and Ca3 (PO4) 2 a simultaneous trans and cis mechanism was found. The ratio of cis to trans mechanism was calculated to be 85/15 with Ca3 (PO4)2, 70/30 with Ba3 (PO4)2 and 45/55 with AlPO4. The cis mechanism is highest for Me-O-distances of the catalysts of 2.5 A which coincides practically with the distance between - OH and -H (D) to be eliminated

Isomerization of butene over a chromia–alumina catalyst

1969 ◽  
Vol 47 (2) ◽  
pp. 323-329 ◽  
Author(s):  
H. C. Chen ◽  
R. R. Hudgins ◽  
P. L. Silveston
Keyword(s):  
Partial Pressure ◽  
Total Pressure ◽  
Active Sites ◽  
Catalyst Deactivation ◽  
Surface Reactions ◽  
Alumina Catalyst ◽  
Isomerization Rate ◽  
Partial Pressures ◽  
Cis And Trans ◽  
Micro Reactor

Isomerization runs were performed in a micro-reactor at 325 °C over a range of butene partial pressure of 84 to 763 mm Hg and at a total pressure of approximately 1 atm. The isomerization rate of 1-butene passed through a maximum with increasing 1-butene partial pressure; the isomerization rate of cis- and trans-2-butene increased asymptotically with increasing cis- and trans-2-butene partial pressures respectively. Stereoselectivity was observed in the isomerization of each butene, and was found to be independent of pressure. Catalyst deactivation resulted in loss in stereoselectivity. Results suggest that surface reactions control isomerization and proceed simultaneously on different active sites.

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