Pt-embedded-CeO2 hollow spheres for enhancing CO oxidation performance

Exploring high-performance catalysts has always been a general concern for promoting extended heterocatalysis reactions. Here, Pt embedded highly-porous CeO2 hollow sphere (Pt/CeO2 HS) composites are developed by a one-pot template-free solvothermal method. Evolution mechanism studies unravel that the Pt/CeO2 HS composites are derived from a self-assembly-reduction-Ostwald ripening process, where Pt nanoparticles (Pt NPs) are embedded into ceria mesoporous hollow spheres. The as-developed embedment strategy is more facile, sustainable and cost-effective than conventional deposition approaches, ensuring the precise control of the location, distribution, and uniformity of Pt NPs throughout the outer shell of hollow spherical CeO2. Importantly, the Pt NP embedding process could be determined to play a key role in creating oxygen vacancies and activating surface chemisorbed oxygen. Besides that, the aggregation of Pt NPs can be efficiently inhibited in the Pt/CeO2 HS composites, and more active sites should be involved in catalytic reactions. All these advantages contribute to the strikingly improved performance as well as excellent stability of the Pt/CeO2 HS composites toward CO oxidation reaction compared with mesoporous CeO2 nanospheres (CeO2 NS) and Pt/CeO2 NS reference catalysts. These findings present a decent protocol for desgining noble metal/oxide hollow structural composites in heterogeneous catalysis.