PRODUCTION OF CERIUM OXIDE HAVING NOVEL MORPHOLOGICAL CHARACTERISTICS

PURPOSE: To increase specific surface area by hydrolyzing an aqueous solution of Ce(IV) salt in an acidic medium to prepare CeO2.2H2O), filtering produced precipitate, washing the precipitate with an organic solvent, drying and then calcining the precipitate at a specified temperature. CONSTITUTION: The Ce(IV) salt such as Ce(NO3)4 of 0.2-0.8 mol/l final equivalent concentration is added to an acidic medium such as 0.3-5 N acidity for 1 to 4 hours, and fluxed under heating at 70-100°C for 1-24 hours. Resulting precipitate of CeO2.2H2O is filtered and washed with the organic solvent such as ethanol 1-3 times. Later it is dried in air or under the reduced pressure of 1×10-2-100 mmHg at 90-200°C for 1-48 hours, then fired at 300-600°C for 30 min-10 hours to obtain CeO2 having ≥85±5 m2/g specific surface area by a BET method. COPYRIGHT: (C)1994,JPO ...