The silica-supported Ru catalysts were prepared by wetness impregnation of silica supports with a stable monodispersed RuO2 colloidal suspension (~2 nm), pre-synthesized from the reaction between RuCl3 and H2O2 according to a reported method .The introduction of RuO2 followed by calcination slightly reduces SBET and Vp (Table ), while the shape of the Type IV isotherms (Fig. )) and the pore size distributions (Fig. ) remain essentially the same for all catalysts. These results suggest that there is no significant modification of the mesoscopic order after the impregnation of Ru species into aerosol silica.