| 摘要 |
PURPOSE: To increase the desorption temperature of hydrocarbons and to improve heat resistance by including silver, group IIIB elements in the periodic table, and crystalline aluminosilicate and ion-exchanging the group IIIB elements by the crystalline aluminum silicate in an adsorbent for hydrocarbon which is used in an exhaust purifier. CONSTITUTION: An adsorbent containing silver, group IIIB elements in the periodic table, and crystalline aluminoslicate is used to adsorb an unburned hydrocarbon in exhaust gas discharged from internal combustion engines such as automobiles. The acid strength of the crystalline aluminum silicate is increased by adding a rare earth element or using colloidal ceria or lanthanum hydroxide sol in the preparation of aluminosilicate to improve the stability of silver after endurance. At least one kind of compound selected from the group consisting of MFI, BEA, FAUD, MOR, FER, ERI, LTL and CHA-type zeolite is used as the crystalline aluminosilicate. |
