ISSN:
1572-879X
Keywords:
TiO2/SiO2
;
mixed metal oxides
;
acidity
;
TGA
;
DRIFTS
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract A series of titania-silica mixed oxides were prepared by co-precipitation and sol-gel methods. The mole fraction of titanium was varied from 0 to 1. The effects of preparation method and chemical composition on the physical properties and acidity profiles of mixed oxides were examined. While pure silica was non-acidic and titania contained only Lewis acid sites, Brønsted acidity was created by the Ti-O-Si interaction in the binary oxides. Samples containing a titania: silica mole ratio of 9 ∶ 1 possessed the largest amount of Brønsted acidity. The generation of acid sites and the stability of the oxide was a strong function of preparation method. With all preparation methods, higher calcination temperatures increased crystallinity and decreased the total number of acid sites.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00816302
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