| 摘要 |
PROBLEM TO BE SOLVED: To remove harmful substances in air without external heating and irradiation of ultraviolet rays by using a material in which noble metal ultra-fine particles are supported on the surface of zinc oxide. SOLUTION: As noble metals used in a catalyst for cleaning air, among platinum, rhodium, palladium, and others, palladium is particularly desirable. In the catalyst, the ultra-fine particles, preferably 1-50 nm in particle size, of a noble metal such as palladium are supported relatively uniformly on the surface of zinc oxide. The zinc oxide is preferably in the form of fine particles having a large surface area per unit weight and can be obtained by a wet process and a dry process. In a wet method in which the noble metal ultra-fine particles are supported on the surface of zinc oxide, the surface of zinc oxide is impregnated with noble metal ions, and after the removal of liquid, the metal is reduced. |
