J. Phys. IV France 7 (1997) C2-941-C2-942
XAFS Studies on the Metal Ion (Cu, Ag) Photocatalysts Prepared Within Zeolite Cavities Using an Ion-Exchange MethodH. Yamashita1, M. Matsuoka1, M. Anpo1 and M. Che2
1 Department of Applied Chemistry, College of Engineering, Osaka Prefecture University, Gakuen-cho, Sakai, Osaka 593, Japan
2 Laboratoire de Réactivité de Surface, Université Pierre et Marie Curie, URA 1106 du CNRS, 4 place Jussieu, Tour 54, 75252 Paris cedex 05, France
Using a combination of in-situ XAFS, photoluminescence and diffuse reflectance measurements, the characterization of the coordination geometry of metal (Cu, Ag) ion photocatalysts prepared within zeolites by an ion-exchange method and thermovacuum treatment has been carried out. The metal ions within zeolites were found to exist as isolated monomers, dimers and clusters, their relative concentration strongly depending of types of zeolites used. Within ZSM-5 and mordenite zeolites, most of the metal ions (Cu+, Ag+) were found to exist as isolated monomers with low coordinate numbers (planar 3 or linear 2 coordinate geometry), in contrast to the case of the Y-zeolite having dimers and/or clusters.
© EDP Sciences 1997