Design of a core shell Pt SiO2 catalyst in a reverse microemulsion system: Distinctive kinetics on CO oxidation at low temperature
Abstract The mechanism of formation of Pt@SiO 2 as a model of core shell nanoparticles via water in oil reverse microemulsions was studied in detail. By controlling the time of growth of Pt precursors, Pt(OH) x after hydrolysis in NH 3 aq. before adding SiO 2 precursor (TEOS) Pt nanoparticles with a narrow size distribution were produced, from ultrafine metal nanoparticles 2 was controllably synthesized from 1 to 15 nm to yield different Pt@SiO 2 materials. The Pt@SiO 2 core shell catalysts exhibited a higher rate of CO oxidation by one order of magnitude with a positive order regarding CO pressure. The SiO 2 shell did not perturb the Pt chemical nature, but it provided different coverage of CO in steady state CO oxidation.