Zoned exhaust system

A catalytic article comprises a flow-through substrate having an inlet, an outlet, and an axial length; a selective catalytic reduction (SCR) zone containing a first SCR catalyst; and an oxidation zone which comprises a platinum group metal (PGM) containing ammonia oxidation catalyst and a PGM-containing DOC catalyst. The PGM-containing ammonia oxidation catalyst and PGM-containing DOC catalyst are arranged in an ammonia slip catalyst (ASC) zone and a separate diesel oxidation catalyst (DOC) zone. The SCR zone is positioned on the substrate from the inlet end and extends less than the axial length of the substrate. The DOC zone is positioned on the substrate from the outlet end to less than the axial length of the substrate. The ASC zone is located between the SCR zone and the DOC zone, wherein the DOC catalyst has a higher concentration of PGM relative to the ammonia oxidation catalyst. An exhaust system comprising the catalytic article is claimed, wherein the system comprises a means for forming NH3, or introducing NH3, in the exhaust gas. A method of providing NOx control coupled with ASC selectivity and DOC capability in the exhaust from a diesel engine during a cold start cycle is also claimed.