J. Phys. IV France
Volume 124, Mai 2005
Page(s) 69 - 73

J. Phys. IV France 124 (2005) 69-73

DOI: 10.1051/jp4:2005124011

RMN du $^{\bf 31}$P et mesure du temps de relaxation de l'acide 12-tungstophosphorique incorporé par synthèse directe dans une charpente silicique mésoporeuse

J. Toufaily1, J.-L. Guth2, M. Soulard2, J. Patarin2, H. Hamad1, 2 and T. Hamieh1, 3

1  Laboratoire de Chimie Analytique, Matériaux, Surfaces et Interfaces (CHAMSI), Département de Chimie, Faculté des Sciences I, Université Libanaise, Hadeth, Beyrouth, Liban
2  Laboratoire de Matériaux Minéraux (UPRES-A-7016,CNRS), ENSCMu, 3 rue Alfred Werner, 68093 Mulhouse Cedex, France
3  Institut de Chimie des Surfaces et Interfaces (ICSI-CNRS), UPR 9096, 15 rue Jean Starcky, BP. 2488, 68057 Mulhouse Cedex, France

The catalytic function of heteropoly compounds has attracted much attention because of their variety and high potential as catalysts. Supported heteropoly acids are generally prepared by impregnation of the active phase by a solution. In this work, we present a new concept for the preparation of a new solid catalyst by direct incorporation of tungstophosphoric species (HPW) into organized mesoporous silica. Synthesis of organized mesoporous silica containing PW was carried out with a mixture of two surfactants, a non ionic one and a cationic one. Taking into account the instability of the tungstophosphate species, the pH domain was restricted to 4-6. The presence of PW species incorporated in the solids was evidenced by solid state 31P NMR. The relaxation times of these solids indicate a weaker mobility of PW in comparison with the impregnated ones.

Key words: organized mesoporous molecular sieves, heteropoly acids, direct incorporation.

© EDP Sciences 2005