Dendrimer templates for supported Au catalysts

Dendrimer templated thiol stabilized gold nanoparticles were evaluated as potential precursors for supported gold catalysts. Gold nanoparticles were prepared in hydroxyl- or alkyl-terminated polyamidoamine dendrimers. The nanoparticles were then extracted from the dendrimer interior with an appropriate hydrophilic or hydrophobic thiol. After deposition onto commercial titania, a variety of conditions were evaluated for removing the thiols. Desorption under nitrogen flows was most appropriate for alkyl thiols, whereas a hydrogen in nitrogen treatment gave the best results for amide containing thiols. CO oxidation catalysis by the resulting supported nanoparticles compared favorably with a standard gold test catalyst.