4-Methylpentan-2-ol dehydration over zirconia catalysts prepared by sol- gel

Ferino, I. and Casula, M.F. and Corrias, A. and Cutrufello, M.G. and Monaci, R. and Paschina, G. (2000) 4-Methylpentan-2-ol dehydration over zirconia catalysts prepared by sol- gel. Physical Chemistry Chemical Physics, 2 (8). pp. 1847-1854. ISSN 1463-9076. (doi:https://doi.org/10.1039/a908992f) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided)

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Official URL
http://dx.doi.org/10.1039/a908992f

Abstract

Zirconia samples have been prepared from xerogels and aerogels obtained using zirconium n-propoxide as precursor. Structure and texture have been investigated by X-ray diffraction, thermal analysis, transmission electron microscopy, nitrogen adsorption/desorption. Surface acidity and basicity have been assessed by adsorption microcalorimetry, using ammonia and carbon dioxide as probe molecules. 4-Methylpentan-2-ol dehydration has been tested at atmospheric pressure in a fixed-bed flow microreactor. The xerogel gives tetragonal zirconia upon calcination, during which a mesoporous system is formed. The crystal phase depends on the presence of oxygen during the cooling step in the case of the aerogel, whose texture is partially retained upon calcination. Both kinds of catalysts have well-balanced concentrations of acid and base sites, but the acid sites are weaker in comparison with the basic ones. At 603 K the initial conversion of 4-methylpentan-2-ol over the calcined xerogel and aerogel is 45 and 63%, respectively; the selectivity to 4-methylpent-1-ene is 77% for both. The occurrence of an E2-like mechanism with the activated complex having a marked carbanionic character seems probable. The aerogel catalyst is quite stable during operation, whereas changes in activity and selectivity are observed for the xerogel catalyst.

Item Type: Article
Uncontrolled keywords: 4 methylpentan 2 ol, unclassified drug, zirconium oxide, article, catalyst, chemical analysis, crystal structure, image analysis, microcalorimetry, structure analysis, thermal analysis, X ray diffraction
Subjects: Q Science > QC Physics > QC176.8.N35 Nanoscience, nanotechnology
Divisions: Faculties > Sciences > School of Physical Sciences > Functional Materials Group
Depositing User: Anna Corrias
Date Deposited: 17 Dec 2014 12:26 UTC
Last Modified: 04 Dec 2017 12:46 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/46228 (The current URI for this page, for reference purposes)
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