초록 ▼

A purification catalyst for exhaust gas enhances the activities of the precious metals, preventing decrease of activities at high temperature, and exhibiting a satisfactory performance during operation. In the purification catalyst of the present invention, Pd is supported by an aluminum composite o

A purification catalyst for exhaust gas enhances the activities of the precious metals, preventing decrease of activities at high temperature, and exhibiting a satisfactory performance during operation. In the purification catalyst of the present invention, Pd is supported by an aluminum composite oxide having a perovskite structure, the aluminum composite oxide is LnAl1-xMxO3 in which Ln is a rare-earth element, and the element M in the LnAl1-xMxO3 is one of elements in groups 1 to 5 and groups 12 to 14.

대표청구항 ▼

What is claimed is: 1. A purification catalyst for exhaust gas, comprising: Pd supported on an aluminum composite oxide having a perovskite structure, wherein the aluminum composite oxide is LnAll-xMxO3 in which Ln is a rare-earth element, and M is one of elements in groups 1 to 5 and groups 12 to

What is claimed is: 1. A purification catalyst for exhaust gas, comprising: Pd supported on an aluminum composite oxide having a perovskite structure, wherein the aluminum composite oxide is LnAll-xMxO3 in which Ln is a rare-earth element, and M is one of elements in groups 1 to 5 and groups 12 to 14, and x is ranging from 0.02 to 0.3. 2. The purification catalyst for exhaust gas according to claim 1, wherein the aluminum composite oxide has a crystal system of trigonal or rhombohedral. 3. The purification catalyst for exhaust gas according to claim 1, wherein the catalyst is produced by adding to an aqueous nitrate solution or an aqueous chloride solution, a compound selected from the group consisting of carboxylic acid having a hydroxyl group or a mereapto group and having a carbon number of 2 to 20, dicarboxylic acid having a carbon number of 2 or 3, and monocarboxylic acid having a carbon number of 1 to 20. 4. The purification catalyst for exhaust gas according to claim 3,wherein the catalyst is produced by evaporating the aqueous nitrate solution or aqueous chloride solution completely, to produce a carboxylic acid complex polymer, and heating said carboxylic acid complex polymer. 5. A purification catalyst device for automobile exhaust gas, comprising: Pd supported on an aluminum composite oxide, which is a pcrovskite for purifying exhaust gas emitted from an automobile, wherein the aluminum composite oxide is LnAll-xMxO3, wherein Ln is a rare-earth element, M is one of elements in groups 1 to 5 and groups 12 to 14, and of x is ranging from 0.02 to 0.3.