High-Temperature-Stable Au@SnO₂ Core/Shell Supported Catalyst for CO Oxidation

High-temperature-stable Au@SnO2 core/shell supported catalyst was prepared by a simple intermetallics-based dry-oxidation approach in which the size of the core can be controlled easily by varying the size of the pre-made Au seeds. The change of their structure was investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). In the as-prepared supported catalysts, Au particles with a mean size of ca. 15 nm were highly encapsulated by the SnO2 shell. Moreover, the Au@SnO2 core/shell supported catalysts showed superior catalytic activity compared to non-encapsulated Au−SnO2. XPS spectra showed that the interactions between the Au catalyst and oxide support in the well-encapsulated Au@SnO2 core/shell nanoparticles are much stronger than those in the non-encapsulated Au−SnO2 nanoparticles, further indicating the synergetic confinement effect in such nanoscaled catalyst/support core/shell systems.