Confining the Nucleation of Pt to In Situ Form (Pt-Enriched Cage)@CeO2 Core@Shell Nanostructure as Excellent Catalysts for Hydrogenation Reactions.

Ultrathin (Pt-enriched cage)@CeO2 core@shell nanostructures are successfully fabricated via a facile hard-template method. It is found that the usage of Pd@Ag@CeO2 bi-metallic core@shell nanostructure as the hard template plays an important role in avoiding the independent nucleation of Pt metal during the galvanic replacement process between K2 PtCl4 and Ag components. This unique core@shell samples show extraordinary activity and selectivity for the cinnamaldehyde hydrogenation reaction. It can achieve over 95% conversion with 87% selectivity of hydrocinnamaldehyde in 5 h under 1 atm H2 pressure. It is considered that such high catalytic performance could be attributed to the densely CeO2 -coated core@shell hybrid form as well as the ultrathin nature of the Pt-enriched cage.