Patent ID: 8206671

Claim:
A method for producing a porous composite metal oxide, the method comprising: (a) mixing (i) a solution comprising a first metal element in an organic solvent with (ii) an emulsion comprising one or more second metal element in an aqueous phase within reverse micelles formed by a surfactant and an organic phase, the first metal element being one of zirconium and cerium and the second metal element being the other of zirconium and cerium; (b) hydrolyzing the first metal element at an interface of the reverse micelles and incorporating the second metal element with the first metal element being hydrolyzed; (c) forming primary particles of a precursor of the composite oxide by polycondensation; (d) aggregating the primary particles to form secondary particles in a system containing the primary particles; and (e) aggregating the secondary particles; wherein a volume of the organic phase outside the reverse micelles is larger than a volume of the aqueous phase inside the reverse micelles and a volume of the surfactant.