US 12,296,319 B2
Composite, zoned oxidation catalys for a compression ignition internal combustion engine
Andrew Chiffey, Royston (GB); Kieran Cole, Rosyton (GB); Oliver Cooper, Royston (GB); Christopher Daly, Royston (GB); Lee Gilbert, Royston (GB); Robert Hanley, Royston (GB); David Micallef, Royston (GB); Francois Moreau, Royston (GB); Paul Phillips, Royston (GB); and George Platt, Royston (GB)
Assigned to Johnson Matthey Public Limited Company, London (GB)
Filed by JOHNSON MATTHEY PUBLIC LIMITED COMPANY, London (GB)
Filed on Oct. 25, 2023, as Appl. No. 18/493,835.
Application 18/493,835 is a continuation of application No. 17/594,694, granted, now 11,845,064, previously published as PCT/EP2020/068165, filed on Jun. 26, 2020.
Claims priority of application No. 19182733 (EP), filed on Jun. 26, 2019; application No. 1914958 (GB), filed on Oct. 16, 2019; and application No. 2004768 (GB), filed on Mar. 31, 2020.
Prior Publication US 2024/0091745 A1, Mar. 21, 2024
Int. Cl. B01J 21/04 (2006.01); B01D 53/94 (2006.01); B01J 21/08 (2006.01); B01J 23/02 (2006.01); B01J 23/42 (2006.01); B01J 23/44 (2006.01); B01J 23/46 (2006.01); B01J 23/58 (2006.01); B01J 37/02 (2006.01); F01N 3/02 (2006.01); F01N 3/023 (2006.01); F01N 3/10 (2006.01)
CPC B01J 23/44 (2013.01) [B01J 21/08 (2013.01); B01J 23/42 (2013.01); B01J 37/0215 (2013.01); F01N 3/0231 (2013.01); F01N 3/10 (2013.01); F01N 2570/10 (2013.01); F01N 2570/12 (2013.01); F01N 2570/14 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A composite oxidation catalyst for use in an exhaust system for treating an exhaust gas produced by a vehicular compression ignition internal combustion engine and located upstream of a particulate matter filter in the exhaust system, the composite oxidation catalyst comprising:
a honeycomb flow-through substrate monolith having a total length L and a longitudinal axis and having a substrate surface extending axially between a first substrate end and a second substrate end;
two catalyst washcoat zones arranged axially in series on and along the substrate surface, wherein a first catalyst washcoat zone having a length L1, wherein L1<L, is defined at one end by the first substrate end and at a second end by a first end of a second catalyst washcoat zone having a length L2, wherein L2<L, wherein the second catalyst washcoat zone is defined at a second end thereof by the second substrate end, wherein the first catalyst washcoat zone comprises a first refractory metal oxide support material and two or more platinum group metal components supported thereon comprising both platinum and palladium at a weight ratio of platinum to palladium of ≥1; and the second catalyst washcoat zone comprises a second refractory metal oxide support material and one or more platinum group metal components supported thereon; and
a washcoat overlayer extending axially from the first substrate end for protecting at least part of an underlying first catalyst washcoat zone from phosphorus and/or zinc poisoning when in use, which washcoat overlayer comprising a particulate metal oxide loading of >0.8 g/in3, wherein the particulate metal oxide has a mean pore diameter of ≥10 nm and/or the washcoat overlayer has a mean interparticle pore diameter of >10 nm,
wherein a total platinum group metal loading in the first catalyst washcoat zone defined in grams of platinum group metal per cubic foot of substrate volume (g/ft3) is greater than a total platinum group metal loading in the second catalyst washcoat zone and wherein the first catalyst washcoat zone comprises a barium or strontium as a first alkaline-earth metal component supported on the first refractory metal oxide support material.