Article abstract
Nature Materials
Published online: 23 November 2008 | doi:10.1038/nmat2329
Thermally stable Pt/mesoporous silica core–shell nanocatalysts for high-temperature reactions
Sang Hoon Joo, Jeong Young Park, Chia-Kuang Tsung, Yusuke Yamada, Peidong Yang & Gabor A. Somorjai
Abstract
Recent advances in colloidal synthesis enabled the precise control of the size, shape and composition of catalytic metal nanoparticles, enabling their use as model catalysts for systematic investigations of the atomic-scale properties affecting catalytic activity and selectivity. The organic capping agents stabilizing colloidal nanoparticles, however, often limit their application in high-temperature catalytic reactions. Here, we report the design of a high-temperature-stable model catalytic system that consists of a Pt metal core coated with a mesoporous silica shell (Pt@mSiO2). Inorganic silica shells encaged the Pt cores up to 750 °C in air and the mesopores providing direct access to the Pt core made the Pt@mSiO2 nanoparticles as catalytically active as bare Pt metal for ethylene hydrogenation and CO oxidation. The high thermal stability of Pt@mSiO2 nanoparticles enabled high-temperature CO oxidation studies, including ignition behaviour, which was not possible for bare Pt nanoparticles because of their deformation or aggregation. The results suggest that the Pt@mSiO2 nanoparticles are excellent nanocatalytic systems for high-temperature catalytic reactions or surface chemical processes, and the design concept used in the Pt@mSiO2 core–shell catalyst can be extended to other metal/metal oxide compositions.
- Department of Chemistry, University of California and Chemical Sciences and Materials Sciences Divisions, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
Correspondence to: Gabor A. Somorjai e-mail: somorjai@berkeley.edu
