ISSN:
1573-4846
Schlagwort(e):
magnesia-silica mixed oxides
;
sol-gel magnesia-silica
;
magnesia-silica acidity
;
sulfated magnesia-silica
;
isopropanol decomposition
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Chemie und Pharmazie
Notizen:
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.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1023/A:1026487018502
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