Preparation of Magnetically Recyclable Yolk/Shell Fex Oy /PdPt@CeO2 Nanoreactors with Enhanced Catalytic Activity.

Abstract

Noble metal nanoparticles (NPs) have recently received considerable attention from researchers working in the field of catalysis. However, the development of new methods allowing these materials to reach their maximum catalytic properties remains challenging. Nanoreactors could lead to dramatic improvements in activity with the help of the intrinsic confinement effect. In this study, we designed a series of yolk/shell Fex Oy /PdPt@CeO2 composites, where the Fex Oy NPs acted as a movable core, allowing for the uniform distribution of the PdPt alloys on the inner surface of the CeO2 shell. The high porosity and existence of hollow voids in the CeO2 shell allowed these Fex Oy /PdPt@CeO2 composites to be used as nanoreactors in catalytic reactions. As well this confinement effect, we identified two structural features that led to enhanced catalytic activity, including (i) the replacement of monometallic NPs with a bimetallic PdPt alloy and (ii) the replacement of a chemically inert support with a reactive CeO2 shell. The resulting nanoassembled catalysts displayed higher activities toward the catalytic reduction of dyes than the reference samples. Moreover, these catalysts were readily recovered and reused because of the magnetic Fex Oy core.