Synthesis of doped ceria with mesoporous flowerlike morphology and its catalytic performance for CO oxidation

Mesporous flowerlike ceria Ce0.9M0.1O2−δ (M = Y, La, Zr, Pr and Sn) have been synthesized successfully by a hydrothermal method. The impacts of doping on their physical properties are investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen adsorption, Raman and X-ray photoelectron spectroscopy (XPS). The doped materials show relatively high stability against the grain growth at 800 °C under reducing and oxidizing atmosphere. The catalytic activities of all flowerlike ceria materials for CO conversion are quite high (200 < T50 < 320 °C) due to their high specific surface area (>100 m2/g), open mesoporous structure (pore size ∼ 3.9 nm) and nano-crystalline nature (grain size < 10 nm). Among flowerlike materials, Pr and Sn doped ceria show enhanced activity while La, Y, Zr doped ceria show decreased activity compared to undoped ceria.