Methods of making highly dispersed substantially uniform cerium and zirconium mixed-metal-oxide composite supports for exhaust conversion catalysts

摘要

A method of making a unique, promoted support for improved catalysts for conversion of exhaust from internal combustion engines, said support comprising a mixed-metal-oxide promoter containing at least Ce and Zr substantially uniformly dispersed as homogeneous crystallites of less than about 100 ANGSTROM on a high-surface-area refractory oxide support substrate, comprising dissolving a combination of Ce- and Zr-oxide precursors, and optionally another metal oxide precursor, and a compatible organic depositing agent, slowly heating to transform the depositing agent into a gel-like matrix coating the substrate in which the mixed-metal-oxide precursor compounds are uniformly distributed and thereafter calcining to burn off the organic matrix and form the appropriate oxide morphology.