Patent ID: 6171572
Filing Date: 2001-01-09
Classification: B01D,B01J,C01G

Abstract:
A method for preparing the zirconium--cerium composite oxide comprising zirconium and cerium at a weight ratio in a range of 51 to 95:49 to 5 in terms of zirconium oxide and ceric oxide, said composite oxide having a specific surface area of not smaller than 50 m.sup.2 /g, wherein said composite oxide is capable of maintaining a specific surface area of not smaller than 20 m.sup.2 /g even after heating at 1100.degree. C. for 6 hours, said method comprising the steps of:reacting under heating a mixture comprising zirconium hydroxide powders having an average particle size of 0.5 to 50 .mu.m and a cerium sol having an average colloidal particle size of 3 to 100 nm, in the presence of 5 to 10 moles of nitric acid per mole of cerium in said mixture,adding a base, and reacting a resulting mixture to precipitate a product, and calcining said product at 500 to 1000.degree. C.