Minimization of purge NOx release from NOx traps by optimizing the oxygen storage capacity
    20.
    发明授权
    Minimization of purge NOx release from NOx traps by optimizing the oxygen storage capacity 有权
    通过优化氧气存储容量,最大限度地减少NOx捕集器的NOx排放

    公开(公告)号:US07238640B2

    公开(公告)日:2007-07-03

    申请号:US10707659

    申请日:2003-12-30

    IPC分类号: B01J23/00 B01J21/00 B01J20/00

    摘要: The present invention provides a catalyst for use in a NOx trap that has reduced NOx release during rich purges, increased NO conversion efficiency under stoichiometric conditions, and improved sulfur tolerance. The catalyst of this embodiment includes a precious metal, an oxygen storage component in contact with the precious metal, and a NOx storage material. The oxygen storage component in contact with the precious metal is present in an amount that provides sufficient oxygen storage capacity to reduce the NOx release from the NOx trap during rich purges to less than 20% of the NOx that is stored in the NOx trap across the operating temperature window of the NOx trap, increase the NOx conversion efficiency under stoichiometric conditions to a value greater than 70%, and increase the sulfur tolerance of the NOx trap.

    摘要翻译: 本发明提供了一种用于在富集清洗期间减少NO x释放,在化学计量条件下提高NO转化效率和改善硫耐受性的NO X阱捕集器中的催化剂。 该实施方案的催化剂包括贵金属,与贵金属接触的储氧组分和NO x X存储材料。 与贵金属接触的储氧组分以提供足够的储氧能力的量存在,以便在富含清洗期间将NO x 2+释放从NO X 2捕集器中减少至 在NO 陷阱的工作温度窗口中存储在NO 陷阱中的小于20%的NO 增加了 在化学计量条件下的转化效率为大于70%的值,并且增加了NO x陷阱的耐硫性。