摘要 |
<p>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 NO x storage material, more securely.</p> |