Zoned exhaust system

A catalytic article having a flow-through substrate having an inlet, an outlet,and an axial length; an SCR zone containing a first SCR catalyst; and an oxidation zone containing (a) an ASC zone and aDOC zone or (b) a mixed ASC and DOC zone, where the oxidation zone contains an ammonia oxidation catalyst and a DOC catalyst, the SCR zone is positioned on the substrate from the inlet end and extendsless than the axial length of the substrate from the inlet, the DOC zone or the mixed ASC and DOC zone is position on the substrate from the outlet end, and when the DOC zone is present, the ASC zoneis located between the SCR zone and the DOC zone. In other catalytic articles, the ASC zone further comprises a DEC catalyst. Methods of using the catalytic articles in an SCR process, where the amount of ammonia slip is reduced, are also described. 催化制品具有包括入口、出口和轴向长度的流通式基材；包含第SCR催化剂的SCR区；和包含(a)ASC区和DOC区或(b)混合的ASC和DOC区的氧化区，其中氧化区包含氨氧化催化剂和DOC催化剂，SCR区从入口端定位于基材上和从入口延伸至小于基材的轴向长度，DOC区或混合的ASC和DOC区从出口端定位于基材上，和当DOC区存在时，ASC区位于SCR区和D