公开(公告)号：EP1563892A1

公开(公告)日：2005-08-17

申请号：EP05002801.8

申请日：2005-02-10

申请人： Hitachi Ltd.

发明人： Shinotsuka, Norihiro c/o Hitachi Ltd I. P. Group ,  Kuroda, Osamu c/o Hitachi Ltd Int. Prop. Group ,  Kitahara, Yuichi c/o Hitachi Ltd Int. Prop. Group ,  Inoue, Takeshi c/o Hitachi Ltd Int. Prop. Group ,  Hiratsuka, Toshifumi c/o Hitachi Ltd I. P. Group ,  Watanabe, Hiroko c/o Hitachi Ltd Int. Prop. Group ,  Iizuka, Hidehiro c/o Hitachi Ltd Int. Prop. Group

IPC分类号： B01D53/94 ,  F01N3/08

CPC分类号： F01N3/0842 ,  B01D53/9422 ,  B01D53/9431 ,  B01D53/944 ,  B01D53/9477 ,  B01D2255/91 ,  F01N3/0814 ,  F01N3/101 ,  F01N13/009 ,  F01N13/0093 ,  F01N2250/02 ,  F01N2330/02 ,  F01N2330/06 ,  F01N2330/10 ,  F01N2330/12 ,  F01N2570/14 ,  Y02A50/2344 ,  Y02T10/22 ,  Y02T10/24

摘要： The invention relates to an exhaust gas purifying apparatus provided with a lean NOx catalyst (3) supporting a catalyst layer, which contains a NOx trapping component, on a honeycomb substrate formed so as not to cause an alkali attack. The invention prevents trapped NOx from being dissociated and exhausted during the time of a rich spike. A NOx reducing catalyst (4) with the function of reducing NOx by a reductant in a rich or stoichiometric condition, e.g., a three-way catalyst, is disposed downstream of the lean NOx catalyst (3). In the case of increasing the amount of the NOx trapping component in the lean NOx catalyst (3) to enhance a NOx trapping capability, even if a part of trapped NOx is dissociated during the time of the rich spike, the dissociated NOx can be reduced by the NOx reducing catalyst (4) disposed on the downstream side.

摘要翻译： 本发明涉及一种废气净化装置，该废气净化装置具有在不形成碱侵蚀的蜂窝状基板上支撑含有NOx捕获成分的催化剂层的稀薄NOx催化剂（3）。 本发明可防止在富穗期间被捕获的NOx被解离和排出。 具有通过富含或化学计量条件的还原剂例如三元催化剂还原NOx的功能的NOx还原催化剂（4）设置在贫NOx催化剂（3）的下游。 在增加稀NOx催化剂（3）中的NOx捕获成分的量以提高NOx捕获能力的情况下，即使在富峰期间部分捕获的NOx离解，也可以使解离的NOx减少 通过设置在下游侧的NOx还原催化剂（4）。