Pt nanoparticles supported on highly dispersed TiO₂ coated on SBA-15 as an efficient and recyclable catalyst for liquid-phase hydrogenation

A series of TiO₂@SBA-15 composites with different TiO ₂ loadings have been synthesized through hydrolysis of tetrabutyl orthotitanate via a facile sol-gel method in the presence of SBA-15 mesoporous silica. The TiO₂@SBA-15 composites retain the mesostructure of the SBA-15 host, and TiO₂ is highly dispersed and uniformly coated. The TiO₂@SBA-15 composites serve as remarkable supports for Pt nanoparticles, which can be applied efficiently to the liquid-phase hydrogenation of benzaldehyde, its derivatives, and other unsaturated compounds under mild conditions. Of particular note is that the Pt/TiO₂@SBA-15 catalysts can be reused several times without distinct loss in activity or selectivity. The more electron-deficient surface state, together with the structural and physicochemical features of Pt/TiO₂@SBA-15 catalysts, would improve the catalytic activity and reusability toward the liquid-phase hydrogenation of unsaturated compounds.