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Spectroscopic Evidence for Open and Closed Lewis Acid Sites in ZrBEA Zeolitesстатья
Статья опубликована в высокорейтинговом журнале
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 28 октября 2016 г.
- Авторы: Sushkevich Vitaly L., Vimont Alexandre, Travert Arnaud, Ivanova Irina Igorevna
- Журнал: Journal of Physical Chemistry C
- Том: 119
- Номер: 31
- Год издания: 2015
- Издательство: American Chemical Society
- Местоположение издательства: United States
- Первая страница: 17633
- Последняя страница: 17639
- DOI: 10.1021/acs.jpcc.5b02745
- Аннотация: The Lewis acid properties of a series of isolated and well-defined Zr centers in a series of ZrBEA zeolites with different Si/Zr ratio and ZrO2 supported on silicious BEA have been investigated by means of IR spectroscopy of adsorbed probe molecules. Different types of Zr centers have been detected and assigned to (i) four-fold coordinated Zr atoms in framework positions that weakly interact with Lewis bases (closed Lewis site), and (ii) stronger Lewis acid sites associated with four-fold coordinated Zr centers with one Zr–OH hydroxyl group resulting from the hydrolysis of Zr–O–Si bond (open Lewis site). It has been shown that deuterated acetonitrile specifically probes open Lewis sites in ZrBEA, while the use of CO allows distinguishing between the two types Lewis sites. The relative amount of open and closed sites does not linearly depend on the Si/Zr ratio in the sample, which can point to different mechanisms of Zr incorporation from Zr-rich and Zr-poor gels.
- Добавил в систему: Сушкевич Виталий Леонидович