Interspersing CeO x Clusters to the Pt-TiO 2 Interfaces for Catalytic Promotion of TiO 2 -Supported Pt Nanoparticles.

We propose an interface-engineered oxide-supported Pt nanoparticle-based catalyst with improved low-temperature activity toward CO oxidation. By wet-impregnating 1 wt % Ce on TiO 2 , we synthesized hybrid oxide support of CeO x -TiO 2 , in which dense CeO x clusters formed on the surface of TiO 2 . Then, the Pt/CeO x -TiO 2 catalyst was synthesized by impregnating 2 wt % Pt on the CeO x -TiO 2 supporting oxide. Pt-CeO x -TiO 2 triphase interfaces were eventually formed upon impregnation of Pt on CeO x -TiO 2 . The Pt-CeO x -TiO 2 interfaces open up the interface-mediated Mars-van Krevelen CO oxidation pathway, thus providing additional interfacial reaction sites for CO oxidation. Consequently, the specific reaction rate of Pt/CeO x -TiO 2 for CO oxidation was increased by 3.2 times compared with that of Pt/TiO 2 at 140 °C. Our results demonstrate a widely applicable and straightforward method of catalytic activation of the interfaces between metal nanoparticles and supporting oxides, which enabled fine-tuning of the catalytic performance of oxide-supported metal nanoparticle classes of heterogeneous catalysts.