scholarly journals Change in surface area of silica-alumina catalysts caused by sintering in steam atmosphere.

1985 ◽  
Vol 18 (1) ◽  
pp. 71-78 ◽  
Author(s):  
KENJI HASHIMOTO ◽  
TAKAO MASUDA
Keyword(s):  
Surface Area ◽  
Silica Alumina ◽  
Alumina Catalysts

scholarly journals Surface, Acidic and Catalytic Properties of Silica—Alumina Catalysts in Relation to Their Chemical Composition

1997 ◽  
Vol 15 (2) ◽  
pp. 125-134 ◽  
Author(s):  
Th. El-Nabarawy ◽  
L.B. Khalil ◽  
M.A. Hamada ◽  
N. Nawar
Keyword(s):  
Surface Area ◽  
Acid Strength ◽  
Alumina Content ◽  
Complex Nature ◽  
Chemical Compositions ◽  
Adsorption Of Nitrogen ◽  
Silica Alumina ◽  
Coprecipitation Technique ◽  
The Mean ◽  
Alumina Catalysts

Silica–alumina catalysts of varying chemical compositions were prepared under controlled conditions, employing the coprecipitation technique. The surface properties were determined from the adsorption of nitrogen at 77 K. The acidity was investigated by determining the adsorption of pyridine at 423 K and by following its thermal desorption up to 773 K. The conversion of 2-propanol at 523 K and the cracking of cumene at 693 K were investigated using the pulse microcatalytic technique. The surface area decreased and the mean pore volume increased with increasing alumina content. The amount of acid present and its surface density increased while the relative acid strength decreased with an increase in the alumina content. The extent of dehydration of 2-propanol increased with increasing surface acid density and proved to be insensitive to the acid strength. The cracking of cumene appears to depend on the surface area, the amount of acid present and the acid strength of the catalyst, although its dependence on these parameters is of a relative complex nature.

Dimerization of Hexadecene with Acid Mesoporous Silica‐Alumina Catalysts

2021 ◽  
Author(s):  
Narendra Kumar ◽  
Marina Lindblad ◽  
Jaana Makkonen ◽  
Väinö Sippola ◽  
Heidi Österholm ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Silica Alumina ◽  
Alumina Catalysts

ChemInform Abstract: Alkylation of Toluene with 2-Propanol Over Titania-Silica-Alumina Catalysts.

ChemInform ◽  
1989 ◽  
Vol 20 (49) ◽  
Author(s):  
K. V. C. RAO ◽  
K. R. SABU ◽  
C. G. R. NAIR
Keyword(s):  
Silica Alumina ◽  
Alumina Catalysts

Characterization of Catalytic Supports by Infrared Spectroscopy and ESCA

1982 ◽  
Vol 36 (4) ◽  
pp. 361-368 ◽  
Author(s):  
Larry F. Wieserman ◽  
David M. Hercules
Keyword(s):  
Infrared Spectroscopy ◽  
Surface Area ◽  
Elevated Temperatures ◽  
Silica Alumina ◽  
Free Hydroxyl ◽  
Ft Ir ◽  
Catalytic Supports ◽  
Silica And Titania

This study compares the properties of γ-alumina, silica, and titania using ESCA and in situ FT-IR. The FWHM's of the O1s and metal 2p ESCA peaks increased systematically from titania to γ alumina; the O1s/metal 2p ESCA peak area ratios were nearly equal for γ-alumina and silica. For titania, however, the value was half that obtained for γ-alumina. In situ FT-IR showed hydroxyl bands with increasing frequencies from titania to silica. Alumina and titania form carbonate-type structures after exposure to CO at elevated temperatures. Silica exhibited no additional bands after CO treatment that could be assigned to physically adsorbed CO or carbonate-type structures. At 100°C, there is a direct correlation between the specific surface area and the intensity of infrared absorbance of the free-hydroxyl and the hydrogen-bonded hydroxyl bands for silica. The intensities of the infrared bands due to matrix modes were not affected by surface area.

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