J. Phys. Colloques
Volume 47, Numéro C8, Décembre 1986EXAFS and Near Edge Structure IV
|Page(s)||C8-317 - C8-320|
J. Phys. Colloques 47 (1986) C8-317-C8-320
EXAFS AND XANES STUDIES ON THE LOCAL STRUCTURES OF METAL IONS IN METAL DOPED MgO SYSTEMSK. ASAKURA, Y. IWASAWA et H. KURODA
Department of Chemistry, Faculty of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113, Japan
The local structures around the metals in metal-doped MgO catalysts were studied by EXAFS and XANES spectroscopies in connection with their catalysis which markedly depends on the kinds of doped metal ions. In the M-MgO samples (M=Ni2+, Cu2+, and Co2+), the M ions occupied the octahedral sites of MgO lattice by replacement with Mg2+. On the other hand, in the system of M-MgO samples (M = Fe3+ and Cr3+ ) the M ions existed as the cluster structure with a Koch-Cohen type M4-framework. The pair sites of the cation vacancy and basic oxygen atom derived from the cluster formation may be corrected with the specific catalysis for the cross-coupling reaction.