TEMPERATURE-DEPENDENCE OF EXAFS SPECTRA OF SUPPORTED SMALL METAL PARTICLES

Temperature dependence of EXAFS was systematically investigated on small metal (Rh or Ru) particles on three different supports, SiO2, NaY zeolite and TiO2. The observed EXAFS oscillations were analysed by the ratio method combined with the cumulant expansion method. The results of these analyses of EXAFS data revealed the existence of a considerable static disorder. It is also shown that the Debye temperature characteristic of particle surface can be determined from analysis of the temperature dependence of the mean-square relative displacement derived from EXAFS. In Rh/TiO2, the surface Debye temperature was found to be ca. 100 K higher in its strong metal-support interaction (SMSI) state in comparison with the normal state, supporting the decoration model for the SMSI state.