| 摘要 |
PROBLEM TO BE SOLVED: To prevent both of contamination with sulfur and particle growth of a noble metal in a catalyst, in which the noble metal is deposited on a zeolite. SOLUTION: A composite noble metal colloid 3 combining at least one of Pt and Pd, and Rh is deposited on a zeolite. By combining plural noble metals, particle growth of P or the like is prevented. And as a particle size of the composite noble metal colloid 3 is larger than a fine pore size of the zeolite, the composite noble metal colloid 3 is deposited on out of the fine pore of the zeolite. Therefore both of clogging of the fine pore and contamination of the noble metal with sulfur are prevented as the result of that generation of sulfate in the fine pore is prevented. |
