Interspersing CeO_<i>x</i> Clusters to the Pt–TiO₂ Interfaces for Catalytic Promotion of TiO₂-Supported Pt Nanoparticles

Abstract

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 CeOx–TiO2, in which dense CeOx clusters formed on the surface of TiO2. Then, the Pt/CeOx–TiO2 catalyst was synthesized by impregnating 2 wt % Pt on the CeOx–TiO2 supporting oxide. Pt–CeOx–TiO2 triphase interfaces were eventually formed upon impregnation of Pt on CeOx–TiO2. The Pt–CeOx–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/CeOx–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.