INFLUENCE OF PREPARATION METHOD ON THE CHARACTERISTICS OF ALUMINA-YTTRIA CATALYSTS

Alumina-Yttria (1:1) was prepared from nitrate by coprecipitation with aqueous NH3 and urea. The structure, thermal stability and surface pr operties of the catalysts were determined by XRD, DTA, XPS and IR meas urements. Method of precipitation does not affect the valence state of the component atoms and the samples were found to be amorphous. Morph ological studies by SEM indicated a uniform nature for urea precipitat ed catalyst and the catalyst had low surface area. An acidity maximum was observed for catalyst NH3. Catalyst prepared by urea precipitation showed more basicity and maximum activity for (+)-limonene oxide and 3-carene oxide isomerization.