Preparation of CeO2/ZrO2 modified by MgO: Roles of MgO for upgrading redox property

CeO2/ZrO2 modified by MgO has been prepared for the development of thermally stabilized CeO2-ZrO2 solid solution particles. A coprecipitated cerium and zirconium hydroxide coated with Mg species was effective as a precursor for preventing the sintering of CeO2/ZrO2 particles under the reduction at 1473 K and the oxidation at 773 K, where MgO was located in the grain boundary from the observation by a high resolution transmission electron microscope (HRTEM). The modified CeO2/ZrO2 showed a good redox performance, indicating that MgO, which does not react with neither CeO2 nor ZrO2, acts to prevent the deterioration of oxygen storage capacity(OSC) by the sintering as a reaction-barrier material at the grain boundary.