Strong electrostatic adsorption of Pt onto SiO2 partially overcoated Al2O3—Towards single atom catalysts

It is frequently desired to synthesize supported metal catalysts that consist of very small clusters or single atoms. In this work, we combine strong electrostatic adsorption (SEA) of H2PtCl6 and engineered oxide supports to ultimately produce very small Pt clusters, including a large fraction of single Pt atoms. The supports are synthesized by depositing controlled amounts of SiO2 onto Al2O3 (SiO2@Al2O3) that has been previously grafted with bulky organic templates. After the templates are removed, the oxide supports are largely negatively charged, like SiO2, but have small patches of positively charged Al2O3, derived from the regions previously covered by the template. The overall point of zero charge of these materials decreases from pH 6.4 for 1 cycle of SiO2 deposition to a SiO2-like