| 摘要 |
PROBLEM TO BE SOLVED: To demonstrate a high capacity for removing carbon monoxide even at room temperature by a method in which noble metal ultra-fine particles are supported on the surface of a metal oxide selected from the group consisting of titanium oxide, lanthanum oxide, and nickel oxide. SOLUTION: Noble metal ultra-fine particles having a preferable particle size of 1-50 nm is supported on the surface of a metal oxide selected from the group consisting of titanium oxide, lanthanum oxide, and nickel oxide. In this process, the support is done in a relatively uniformly dispersed state so that the contact between external air and the metal oxide is not shut off, namely both the noble metal and the metal oxide are exposed on the surface, or external air can contact the metal oxide through the gaps between the noble metal ultra-fine particles. The metal oxide is preferably particles or aggregates having a large surface area per unit weight. The ultra-fine particles can be obtained by a wet process and a dry process. As for the noble metal, among platinum, rhodium, palladium, and others, palladium is particularly preferable. |
