Please use this identifier to cite or link to this item: https://dspace.univ-ouargla.dz/jspui/handle/123456789/2720
Title: Dawson-type polyoxometalates in Liquid phase isobutane hydroxylation
Authors: L. Dermeche, R. Thouvenot, N. Essayem, C. Rabia
Keywords: polyoxometalates
Liquid phase
hydroxylation
Issue Date: 19-Dec-2013
Series/Report no.: 2012;
Abstract: Dawson polyoxometalates (POMs) have been reported as efficient catalysts for gas- phase oxidative dehydrogenation of isobutane to isobutene [1] and isobutyric acid to methacrylic acid with oxygen molecular as oxidant [2]. In this paper, we have studied the catalytic activity of a series of Dawson-type POMs, as potassium salts, namely K6P2W12Mo6O62, K7P2Mo5VW12O62, P2W10Mo5V3O62 and P2W12V6O62, in the isobutane hydroxylation in acetonitrile solvent with hydrogen peroxide as oxidant. POMs were characterized by FTIR, 31P NMR and BET. Terbutyl alcohol (tert-BuOH), isobutyl alcohol (iso-BuOH), acetone, isopropyl alcohol (iso-PrOH) and isobutyric acid (isoBuOOH) are the products detected in isobutane hydroxylation at 60°C. The distribution of these products depends of POM composition and the framework symmetry. Thus, V free POM didn‟t catalyse liquid isobutane oxidation while V containing POMs promoted the formation of oxygenated products at low temperature. The first major product is isobutiric acid and the second one is tertiobutanol. The investigation of isobutanol and tertiobutanol transformation in equivalent reaction conditions (with or without catalyst) evidenced the formation of isobutyric acid and C3 oxygenated products. This suggests that tertiobutanol and isobutanol would the primary products, while acetone, isopropanol and isobutyric acid would result from successive transformations of the C4 alcohols. The results shown that the presence of vanadium atoms favoured the formation of oxygenated compounds in the isobutane oxidation. The distribution of reaction products depends on the polyanion composition.
Description: 1st International Days of Organometallic Chemistry and Catalysis JICOC Ouargla, February 06- 09, 2012
URI: http://hdl.handle.net/123456789/2720
ISSN: saf
Appears in Collections:1. Faculté des mathématiques et des sciences de la matière

Files in This Item:
File Description SizeFormat 
L. Dermeche.pdf158,68 kBAdobe PDFView/Open


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.