Effects of surface modification by chemical filing on the redox behavior of a ceria-zirconia mixed oxide

A ceria-zirconia mixed oxide was prepared by means of the thermal decomposition of cerium zirconyl oxalate in an argon flow and subsequent removal of the top surface by the formation of volatile complexes of AlCl3-CeCl3 and AlCl3-ZrCl4, ''chemical filing''. The obtained ceria-zirconia sample showed redox behavior at low temperatures even after redox cycles at 1273 K, while the conventional ceria-zirconia samples prepared via hydrogen or carbon reduction released a smaller amount of oxygen at higher temperatures after high temperature redox cycles. High redox activity at low temperatures and high thermal resistance are the requirements for the next generation of ceria-based materials, especially when applied in automotive exhaust cleaning catalysts. (orig.)