초록 ▼

Pd-based composite oxide containing at least one element selected from rare earth metals is used. Therefore, a composite oxide having the same amount of noble metal as in a conventional technique can be burned at a lower temperature. As a result, a purification catalyst for exhaust gas having superi

Pd-based composite oxide containing at least one element selected from rare earth metals is used. Therefore, a composite oxide having the same amount of noble metal as in a conventional technique can be burned at a lower temperature. As a result, a purification catalyst for exhaust gas having superior purification properties in which deterioration of Pd dispersion by crystallization is prevented, and a production method therefor can be provided.

대표청구항 ▼

What is claimed is: 1. A method for production of a purification catalyst for exhaust gas comprising: preparing an aqueous nitrate solution of elements forming a Pd-based composite oxide, the elements consisting of only Pd and at least one element selected from rare earth metals; adding at least on

What is claimed is: 1. A method for production of a purification catalyst for exhaust gas comprising: preparing an aqueous nitrate solution of elements forming a Pd-based composite oxide, the elements consisting of only Pd and at least one element selected from rare earth metals; adding at least one compound selected from the group of compounds consisting of carboxylic acid of carbon number 2 to 20 having a OH group or a SH group, dicarboxylic acid of carbon number 2 or 3, and monocarboxylic acid of carbon number 1 to 20 to the aqueous nitrate solution; preparing a carboxylic acid complex polymer by evaporating and drying the aqueous nitrate solution; and burning the carboxylic acid complex polymer and forming the purification catalyst consisting of only a Pd-rare earth metal composite oxide. 2. The method for production of a purification catalyst for exhaust gas according to claim 1, wherein the burning is carried out at a temperature of not more than 900째 C.