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-tetramethyl disiloxane) platinum(0), to give catalytically active surface-bound pl atinum nanoparticles with an average diameter of 2 nm. The supported p latinum nanoparticles could be recycled through at least three consecu tive hydrosilation reactions while maintaining their catalytic activit y. It is postulated that the mesh microstructure of the grafted hydrid osilsesquioxane layer supports and protects the supported platinum nan oparticles from aggregating into larger inactive platinum species.