Hydridosilsesquioxane Modified Silica-Supported Platinum Nanoparticles

Colloidal silica modified with a hydridosilsesquioxane (HSiO3/2) layer reacted with Karstedt's catalyst, bis(1,3-divinyl,1,1,3,3-tetramethyldisiloxane) platinum(0), to give catalytically active surface-bound platinum nanoparticles with an average diameter of 2 nm. The supported platinum nanoparticles could be recycled through at least three consecutive hydrosilation reactions while maintaining their catalytic activity. It is postulated that the mesh microstructure of the grafted hydridosilsesquioxane layer supports and protects the supported platinum nanoparticles from aggregating into larger inactive platinum species.