THERMOSTABILITY OF CERIA TEXTURE .1. CHAR ACTERIZATION

The evolution of the texture of a ceria powder has been studied at 943 K from the interpretation of nitrogen adsorption isotherms at 77 K by various methods: BET, BJH, t and alpha methods, Dubinin's method. The mean crystallite size has been obtained from X-ray diffraction line b roadening. The comparison of the results from the different methods in dicated that the initial powder exhibits a high microporosity, to whic h corresponds a specific surface area equal to 72 m(-2).g(-1), which r apidly disappeared after few hours of calcination. Simultaneously the mean diameter of ceria crystallites was increased from around 14 to 20 nm.