Integrated SCR and AMOX Catalyst Systems
    41.
    发明申请
    Integrated SCR and AMOX Catalyst Systems 有权
    集成SCR和AMOX催化剂系统

    公开(公告)号:US20100111796A1

    公开(公告)日:2010-05-06

    申请号:US12263871

    申请日:2008-11-03

    摘要: Catalysts, methods of preparing catalyst, and methods for treating exhaust gas streams are described. In one or more embodiments, a catalyst system includes an upstream zone effective to catalyze the conversion of a mixture of NOx and NH3 to N2, and a downstream zone effective for the conversion of ammonia to N2 in the presence or absence of NOx. In an embodiment, a method for preparing a catalyst system includes: first coating one end of a substrate along at least 5% of its length with an undercoat washcoat layer containing a material composition effective to catalyze the removal of ammonia; second coating with an overcoat layer containing a material composition effective to catalyze the conversion of a mixture of NOx and NH3 to N2. A method for treating the exhaust gas stream is provided, which includes injecting ammonia or an ammonia precursor into an exhaust gas stream of a vehicle, passing the engine exhaust gas stream containing NOx and NH3 through the upstream zone of a catalyst system to remove NOx and then passing the exhaust gas stream through the downstream zone of the catalyst system to remove NH3, as well as other oxidizable species such as hydrocarbons and CO.

    摘要翻译: 描述了催化剂,制备催化剂的方法和处理废气流的方法。 在一个或多个实施方案中,催化剂体系包括有效催化NOx和NH 3的混合物转化为N 2的上游区,以及在存在或不存在NO x的情况下有效地将氨转化为N 2的下游区。 在一个实施方案中,制备催化剂体系的方法包括:首先用至少5%长度的基材的一端涂覆含有有效催化去除氨的材料组合物的底涂层涂层; 第二次涂覆,其中包含有效催化NOx和NH 3的混合物转化为N 2的材料组合物的外涂层。 提供了一种处理废气流的方法,其包括将氨或氨前体注入车辆的废气流中,使含有NOx和NH 3的发动机废气流通过催化剂系统的上游区以除去NOx和 然后使废气流通过催化剂体系的下游区以除去NH 3,以及其它可氧化物质如烃和CO。