The controlled calcination of ruthenium complexes together with an aminosilsesquioxane ligand (1) at 823 K in air stream for 4 h afforded porous silicas including monodispersed ruthenium oxide nanoparticles with high surface areas and uniformly controlled micropores. Bimodal porous oxides with both meso- and micropores were prepared by the impregnation of Ru complexes and 1 onto titania (JRC-TIO-4) or silica URC-SIO-1), followed by the careful calcination at 823 K. These bimodal catalysts showed higher activity towards hydroformylation of 1-octene (C-9-aldehydes yield up to 31%, linear selectivity up to 95% in CO 20 atm, H-2 25 atm at 403 K for 20 h with 1.5 mol% Ru catalyst) than the catalysts prepared without an aminosilsesquioxane ligand. (C) 2008 Elsevier B.V. All rights reserved.