Dispersed metal particles supported on porous substrates are widely applied in heterogeneous catalysis. The catalysts usually show activities and selectivities strongly depending on the pretreatment (cleaning/activation) conditions. The noble metal may interact with both reducible (e.g. TiO2) and non-reducible (e.g. SiO2 and Al2O3) oxide supports [1, 2]. This metal support interaction may have drastic effects on the chemisorptive and catalytic properties of the metal phase. Therefore, the investigation of structural changes under various treatment conditions is of great importance for elucidating the mechanism of the metal support interaction.