Abstract: Ultrafine powder of Ce-Zr-Ba mixed oxide was prepared with a macromolecule surface modified method. The
typical structure, particle size, surface area and pore structure of the powder were investigated by TEM, XRD, BET and TG-DTA technologies. The results
show that the Ce-Zr-Ba mixed oxide powder is nano-sized with the particle size of 50nm, and a high surface area of 119.0m²/g at the calcination of
600℃ for 4h. The surface area of the powder remains 87.4m²/g even calcination at 800℃ for 4h. After calcination at 1000℃ for 4h, it will keep good particle distribution and in nano-sized properties.
This powder can be used as the material in three way catalyst (TWC) for its novel character of resistance high temperature and high surface area.

Key words: Ce-Zr solid solution, ultrafine powder, high surface area, material of resistance high temperature