Abstract: A method for the manufacture of a diesel oxidation catalyst comprises: (i) providing a carrier substrate; (ii) forming one or more platinum-group-metal-containing washcoat layers each comprising a refractory metal oxide support material on the carrier substrate to provide a first coated substrate; (iii) subjecting the first coated substrate to a first heat treatment to form a heat-treated coated substrate, wherein the first heat treatment comprises heating the first coated substrate to a first maximum temperature and holding the first coated substrate at the first maximum temperature; (iv) depositing a platinum-group-metal-containing composition comprising a refractory metal oxide support material on at least a portion of the heat-treated coated substrate to form a second coated substrate; and (v) subjecting the second coated substrate to a second heat treatment to form the diesel oxidation catalyst, wherein the second heat treatment comprises heating the second coated substrate to a second maximum temperatur

Abstract: A composite, zone-coated, dual-use ammonia (AMOX) and nitric oxide oxidation catalyst (12) comprises: a substrate (5) having a total length L and a longitudinal axis and having a substrate surface extending axially between a first substrate end (I) and a second substrate end (O); two or more catalyst washcoat zones (1; 2) comprised of a first catalyst washcoat layer (9) comprising a refractory metal oxide support material and one or more platinum group metal components supported thereon and a second catalyst washcoat layer (11) different from the first catalyst washcoat layer (9) and comprising a refractory metal oxide support material and one or more platinum group metal components supported thereon, which two or more catalyst washcoat zones (1; 2) being arranged axially in series on and along the substrate surface, wherein a first catalyst washcoat zone (1) having a length L1, wherein L1<L, is defined at one end by the first substrate end (I) and at a second end (13) by a first end (15) of a second catal

Abstract: A composite oxidation catalyst for use in an exhaust system for treating an exhaust gas produced by a vehicular compression ignition internal combustion engine is disclosed. The composite oxidation catalyst comprises a honeycomb flow-through substrate monolith and two catalyst washcoat zones arranged axially in series on and along the substrate surface.

Abstract: A composite oxidation catalyst for use in an exhaust system for treating an exhaust gas produced by a vehicular compression ignition internal combustion engine is disclosed. The composite oxidation catalyst comprises a honeycomb flow-through substrate monolith and two catalyst washcoat zones arranged axially in series on and along the substrate surface.

Abstract: A composite oxidation catalyst (18, 20) for use in an exhaust system for treating an exhaust gas produced by a vehicular compression ignition internal combustion engine (30) and upstream of a particulate matter filter (44, 50) in the exhaust system comprises a substrate (5) having a total length L and a longitudinal axis and having a substrate surface extending axially between a first substrate end (I) and a second substrate end (O); and three or more catalyst washcoat zones (1, 2, 3; or 1, 2, 3, 4) arranged axially in series on and along the substrate surface, wherein a first catalyst washcoat zone (1) having a length L1, wherein L1<L, is defined at one end by the first substrate end (I) and at a second end by a first end (19, 21) of a second catalyst washcoat zone (2) having a length L2, wherein L2<L, wherein the first catalyst washcoat zone (1) comprises a first refractory metal oxide support material and two or more platinum group metal components supported thereon comprising both platinum and palla

Abstract: A composite oxidation catalyst (18, 20) for use in an exhaust system for treating an exhaust gas produced by a vehicular compression ignition internal combustion engine (30) and upstream of a particulate matter filter (44, 50) in the exhaust system comprises a substrate (5) having a total length L and a longitudinal axis and having a substrate surface extending axially between a first substrate end (I) and a second substrate end (O); and three or more catalyst washcoat zones (1, 2, 3; or 1, 2, 3, 4) arranged axially in series on and along the substrate surface, wherein a first catalyst washcoat zone (1) having a length L1, wherein L1<L, is defined at one end by the first substrate end (I) and at a second end by a first end (19, 21) of a second catalyst washcoat zone (2) having a length L2, wherein L2<L, wherein the first catalyst washcoat zone (1) comprises a first refractory metal oxide support material and two or more platinum group metal components supported thereon comprising both platinum and palla

Abstract: 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 a DOC 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 extends less 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 zone is 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.

Abstract: 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 a DOC 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 extends less 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 zone is 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.