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 (T50 = ~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.