Nanostructured Titania-Supported Ceria-Samaria Solid Solutions: Structural Characterization and CO Oxidation Activity

In this work, a novel nanostructured TiO2 supported CeO2-Sm2O3 (CS/T) catalyst was prepared by deposition coprecipitation method and then evaluated for CO oxidation. The role of TiO2 support in the CS/T catalyst was studied by comparing its physicochemical and catalytic properties with the unsupported CeO2-Sm2O3 (CS) and CeO2. Under identical conditions, the CS/T catalyst showed better activity with lower light-off temperature (T-50 = similar to 547 K) compared to the CS and CeO2. Characterization results revealed the constructive structural modifications in the CS/T catalyst owing to the strong synergistic effect between the CeO2-Sm2O3 and TiO2 support, which significantly influenced the catalytic performance for CO oxidation. The highly dispersed Ce-O-Sm solid solution over the TiO2 support leads to large specific surface area, more oxygen vacancies and active oxygen species, which are responsible for better activity of CS/T catalyst. Further, the CS/T catalyst exhibits high reusability (up to three runs) and good long-term stability (48 h) without appreciable loss of catalytic activity. [GRAPHICS] .