J. Phys. IV France 7 (1997) C2-911-C2-912
Mg K-Edge XAFS Study of Silica-Magnesia SystemsH. Yoshida1, T. Yoshida2, T. Tanaka2, T. Funabiki2, S. Yoshida2, T. Abe1, K. Kimura1 and T. Hattori1
1 Department of Applied Chemistry, School of Engineering, Nagoya University, Nagoya 464-01, Japan
2 Department of Molecular Engineering, School of Engineering, Kyoto University, Kyoto 606-01, Japan
Mg K-edge XAFS study was carried out to clarify the local structure of silica-magnesia systems prepared in four ways ; by impregnation of silica with an aqueous solution of magnesium nitrate or with a methanol solution of magnesium methoxide, and by sol-gel method with tetraethyl orthosilicate and magnesium solutions mentioned above. It is clarified that the preparation method decides the structure of Mg species respectively ; (i) MgO particle on silica, (ii) dispersed Mg species on silica surface, (iii) dispersed Mg tetrahedral species in silica bulk.
© EDP Sciences 1997