Synthesis, characterization and catalytic property of ceria spherical nanocrystals

Ceria nanocrystals and CuO–CeO2 composite were prepared via alcohothermal technique using methanol as the solvent firstly and impregnation method. The catalytic activity of the samples was studied for low-temperature CO oxidation. High-resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) showed that the prepared spherical CeO2 was cubic phase with good crystallinity and narrow particle size distribution. CuO was in non-crystal form in the CuO–CeO2 composite. Temperature-programmed reduction (TPR) and X-ray photoelectron spectra (XPS) analysis of the CuO–CeO2 composite indicated a two-step reduction and the possible presence of reduced copper species. The CuO–CeO2 composite exhibited obviously higher catalytic activity than CeO2 due to the synergistic effect.