Abstract: Different nanometer CeO2-ZrO2 mixed oxides doped with lanthanum or ~praseodymium were prepared by coprecipi-tation. The characteristics of all mixed oxides were tested by XRD, SEM, TEM, and XPS. XRD results showed that all oxides were formed solid solution with CaF2 structure at low temperature and had good thermal stability. More Ce4+ ions were rich on the surface by XPS, which were beneficial to oxygen storage. The particle mediun sizes (d50) of all oxides powders were approximately 10~20 nm by small angle scattering goniometer. When doped Zr4+ in CeO2, the specific surface areas were improved at low or high temperature. The area of Ce0.6Zr0.3La0.04Pr0.06O2 powder had excess 110 m2/g after calcining at 923 K for 4h, even calcined at 1273 K for 4 h, the area was up to 65 m2/g.

Key words: Ceria-zirconia, Solid solution, Nanometer, High surface area