Catalytic activity study of ceria-zirconia mixed oxides submitted to different aging treatments under simulated exhaust gases

A Ce/Zr mixed oxide with a molar ratio of 68/32 was submitted to aging trea tments in different environments: one oxidizing, one reducing, and one in w hich the feedstream was continuously changing between oxidizing and reducin g through the stoichiometric composition. The textural evolutions of the di fferently aged samples have been compared to each other and also to the fre sh sample and have been related to the samples' activities as three-way cat alysts. The activities of the samples have been found to depend not only on the samples' final specific surface areas but also an the reducing or oxid izing nature of the aging treatment. Thus, it has been pointed out that an aging feedstream as similar as possible to the actual one in real operation should be used when performing durability studies to arrive at reliable co nclusions.