Temperature dependence of EXAFS spectra of supported small metal particles

Abstract

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.