In-situ high-temperature XANES observations of rapid and reversible changes in Ti coordination in titania-silica xerogels
UNSPECIFIED. (1999) In-situ high-temperature XANES observations of rapid and reversible changes in Ti coordination in titania-silica xerogels. CHEMICAL PHYSICS LETTERS, 304 (3-4). pp. 150-154. ISSN 0009-2614Full text not available from this repository.
The height and position of the pre-edge peak in Ti K-edge X-ray absorption near-edge structure (XANES) is a sensitive indicator of the coordination of Ti. This method is used in situ to investigate Ti coordination in titania-silica xerogels with low TiO2 content. Unheated xerogels contain Ti with isolated, distorted 6-fold coordination (Ti-). Initial heating causes [Ti- to be rapidly converted into 4-fold coordinated Ti(Ti-), which upon cooling reverts to Ti-. Increased heat treatment creates more stable Ti-, which remains after cooling. Thus, the coordination of Ti depends on ambient conditions in addition to heat treatment. In-situ XANES is important for distinguishing different kinds of Ti-, and hence for understanding catalytic properties. (C) 1999 Elsevier Science B.V. All rights reserved.
|Item Type:||Journal Article|
|Subjects:||Q Science > QD Chemistry
Q Science > QC Physics
|Journal or Publication Title:||CHEMICAL PHYSICS LETTERS|
|Publisher:||ELSEVIER SCIENCE BV|
|Date:||30 April 1999|
|Number of Pages:||5|
|Page Range:||pp. 150-154|
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