| 摘要 |
PURPOSE: A nitrogen oxide reducing catalyst with enhanced low temperature activity is provided to ensure the superior activity of the catalyst regardless of temperatures by using both a copper-zeolite catalyst and an iron-zeolite catalyst. CONSTITUTION: A first catalyst layer of copper-zeolite is coated on a carrier layer. A second catalyst layer of iron-zeolite is coated on the first catalyst layer. The coated amount of the second catalyst layer is less than the coated amount of the first catalyst layer. The contents of copper and iron in the copper-zeolite and the iron-zeolite compounds are in a range between 2 and 5 weight%, respectively. The weight ratio for the coated amounts of the first catalyst layer and the second catalyst layer is 1:0.1-0.9 based on the contents of the metals. [Reference numerals] (AA) NOx removal rate(%); (BB) Iron-zeolite; (CC) Copper-zeolite; (DD) Fe+Cu physical mixture; (EE) Reaction temperature(°C) |
