| 摘要 |
PURPOSE:To obtain a catalyst which traps particulates in exhaust gas and has excellent performance in purification of CO by depositing base metal catalyst and platinum catalyst on a foam-type heat-resistant porous filter having two layers of different density. CONSTITUTION:The foam-type heat-resistant porous film consists of a part having rather low density and a thin layer having high density formed on one side of the filter. The low-density part carries alkali metal which can burn particulates, and transition elements of I-B group, II-B group, V-A group (V, Nb, Ta), VI-A group (Co, Mo, W), VII-A group (Mn, Re), VIII-A group (Fe, Co, Ni) excluding Pt, and Sn in periodic table. The thin layer of high density carries platinum catalyst which can purify unburnt hydrocarbons and CO. By this method, a catalyst device for purifying exhaust gas is obtained and is suitable for diesel engine. |
