Interspersing CeO Clusters to the Pt-TiO₂ Interfaces for Catalytic Promotion of TiO₂-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 TiO₂, we synthesized hybrid oxide support of CeO-TiO₂, in which dense CeO clusters formed on the surface of TiO₂. Then, the Pt/CeO-TiO₂ catalyst was synthesized by impregnating 2 wt % Pt on the CeO-TiO₂ supporting oxide. Pt-CeO-TiO₂ triphase interfaces were eventually formed upon impregnation of Pt on CeO-TiO₂. The Pt-CeO-TiO₂ 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-TiO₂ for CO oxidation was increased by 3.2 times compared with that of Pt/TiO₂ 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.