摘要 |
A catalytic support 10 is made of rare-earth-element-oxide fine particles (e.g., ceria fine particles 11) comprising primary particles of a rare-earth element oxide, alumina fine particles 12 comprising primary particles of alumna, and barium-compound fine particles 13 comprising primary particles of a barium compound, rare-earth-element-oxide fine particles, alumina fine particles 12 and barium-compound fine particles 13 which are mixed with each other. A primary particle diameter of the rare-earth-element-oxide fine particles is 5 nm or less, and a primary particle diameter of the barium-compound fine particles 13 is 10 nm or less. Platinum fine particles 20 are supported, of this catalytic support 10, on the rare-earth-element-oxide fine particles virtually. It is possible to suppress the granular growth of platinum, which serves an oxidizing catalyst, and the granular growth of barium, which serves an NOx storage material, more securely.
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