J. Phys. IV France 7 (1997) C2-703-C2-704
Adsorption of SO2 on Pd(100) Studied by S K-Edge XAFSS. Terada1, M. Sakano1, Y. Kitajima2, T. Yokoyama1 and T. Ohta1
1 Department of Chemistry, Graduate School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113, Japan
2 Photon Factory, National Laboratory for High Energy Physics, Oho, Tsukuba, Ibaraki 305, Japan
Surface structure and an electronic property of SO2 adsorbed on Pd(100) were studied by S K-edge NEXAFS, SEXAFS and S1s XPS. The molecule was found by the polar-angle dependent NEXAFS to adsorb with the molecular plane normal to the Pd(100) surface. This is a clear contrast to the SO2/Ni(100) case where the molecule lies flat on the surface. From the peak position of XPS and the π* peak height of the NEXAFS spectra, we can deduce that the amount of the charge transfer from Pd to SO2 is smaller than that from Ni. The SEXAFS analysis indicates that the S atom of the molecule is located at the bridge site and that one O atom also directly interacts with the metal surface. The difference of the adsorbate structure between SO2/Pd and SO2/Ni can be explained in terms of chemical bonding between the substrate and SO2.
© EDP Sciences 1997