ISSN:
1573-4846
Keywords:
magnesia-silica mixed oxides
;
sol-gel magnesia-silica
;
magnesia-silica acidity
;
sulfated magnesiasilica
;
isopropanol decomposition
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Mg−Si binary oxides were prepared by the sol-gel method, using magnesium diethoxide and tetraethoxysilane as starting materials. Mg−Si mixed oxides were prepared at pH3 and 9 at nominal concentrations of 1.3, 4.0, and 6.7 mole% MgO. Density and strength of the acid sites were determined by pyridine thermal programmed desorption. Comparable Lewis acidity was found in pH3 and 9 preparations. However, when the samples were sulfated with sulfuric acid, strong Bronsted acidity was developed, reaching a maximum at 6.7 mole% MgO. The strong acidity of sulfated samples was corroborated using the isopropanol decomposition reaction as catalytic test. Similar conversions are obtained at 100°C on sulfated samples, whereas 260°C are required for non-sulfated ones.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02436859
Permalink
