WO2012071421A2 - Diesel oxidation catalyst articles and methods of making and using - Google Patents

Diesel oxidation catalyst articles and methods of making and using Download PDF

Info

Publication number
WO2012071421A2
WO2012071421A2 PCT/US2011/061860 US2011061860W WO2012071421A2 WO 2012071421 A2 WO2012071421 A2 WO 2012071421A2 US 2011061860 W US2011061860 W US 2011061860W WO 2012071421 A2 WO2012071421 A2 WO 2012071421A2
Authority
WO
WIPO (PCT)
Prior art keywords
washcoat layer
substrate
catalytic article
palladium
washcoat
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/US2011/061860
Other languages
French (fr)
Other versions
WO2012071421A3 (en
Inventor
Xinyi Wei
Stanley Roth
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BASF Corp
Original Assignee
BASF Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=46063019&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=WO2012071421(A2) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Priority to BR112013013008-3A priority Critical patent/BR112013013008B1/en
Priority to CA2818860A priority patent/CA2818860A1/en
Priority to JP2013541025A priority patent/JP5843880B2/en
Priority to CN2011800637118A priority patent/CN103313787A/en
Priority to MX2013005886A priority patent/MX342674B/en
Application filed by BASF Corp filed Critical BASF Corp
Priority to KR1020137016164A priority patent/KR101862814B1/en
Priority to EP11843705.2A priority patent/EP2643082B1/en
Publication of WO2012071421A2 publication Critical patent/WO2012071421A2/en
Publication of WO2012071421A3 publication Critical patent/WO2012071421A3/en
Anticipated expiration legal-status Critical
Priority to ZA2013/04549A priority patent/ZA201304549B/en
Ceased legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J19/24—Stationary reactors without moving elements inside
    • B01J19/248—Reactors comprising multiple separated flow channels
    • B01J19/2485—Monolithic reactors
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
    • B01J23/40—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals of the platinum group metals
    • B01J23/44—Palladium
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
    • B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
    • B01D53/944—Simultaneously removing carbon monoxide, hydrocarbons or carbon making use of oxidation catalysts
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J19/24—Stationary reactors without moving elements inside
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
    • B01J23/54—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/56—Platinum group metals
    • B01J23/63—Platinum group metals with rare earths or actinides
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J29/00—Catalysts comprising molecular sieves
    • B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J29/00—Catalysts comprising molecular sieves
    • B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
    • B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
    • B01J29/70—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of types characterised by their specific structure not provided for in groups B01J29/08 - B01J29/65
    • B01J29/72—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of types characterised by their specific structure not provided for in groups B01J29/08 - B01J29/65 containing iron group metals, noble metals or copper
    • B01J29/74—Noble metals
    • B01J29/7415—Zeolite Beta
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00—Catalysts, in general, characterised by their form or physical properties
    • B01J35/19—Catalysts containing parts with different compositions
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/02—Impregnation, coating or precipitation
    • B01J37/024—Multiple impregnation or coating
    • B01J37/0244—Coatings comprising several layers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/02—Impregnation, coating or precipitation
    • B01J37/024—Multiple impregnation or coating
    • B01J37/0246—Coatings comprising a zeolite
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/02—Impregnation, coating or precipitation
    • B01J37/024—Multiple impregnation or coating
    • B01J37/0248—Coatings comprising impregnated particles
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen; Reversible storage of hydrogen
    • C01B3/02—Production of hydrogen; Production of gaseous mixtures containing hydrogen
    • C01B3/22—Production of hydrogen; Production of gaseous mixtures containing hydrogen by decomposition of gaseous or liquid organic compounds
    • C01B3/24—Production of hydrogen; Production of gaseous mixtures containing hydrogen by decomposition of gaseous or liquid organic compounds of hydrocarbons
    • C01B3/26—Production of hydrogen; Production of gaseous mixtures containing hydrogen by decomposition of gaseous or liquid organic compounds of hydrocarbons using catalysts
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G45/00—Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds
    • C10G45/02—Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds to eliminate hetero atoms without changing the skeleton of the hydrocarbon involved and without cracking into lower boiling hydrocarbons; Hydrofinishing
    • C10G45/04—Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds to eliminate hetero atoms without changing the skeleton of the hydrocarbon involved and without cracking into lower boiling hydrocarbons; Hydrofinishing characterised by the catalyst used
    • C10G45/10—Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds to eliminate hetero atoms without changing the skeleton of the hydrocarbon involved and without cracking into lower boiling hydrocarbons; Hydrofinishing characterised by the catalyst used containing platinum group metals or compounds thereof
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
    • F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
    • F01N3/033—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters in combination with other devices
    • F01N3/035—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters in combination with other devices with catalytic reactors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/0807—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents
    • F01N3/0828—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents characterised by the absorbed or adsorbed substances
    • F01N3/0835—Hydrocarbons
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
    • F01N3/103—Oxidation catalysts for HC and CO only
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/10—Noble metals or compounds thereof
    • B01D2255/102—Platinum group metals
    • B01D2255/1021—Platinum
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/10—Noble metals or compounds thereof
    • B01D2255/102—Platinum group metals
    • B01D2255/1023—Palladium
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/20—Metals or compounds thereof
    • B01D2255/206—Rare earth metals
    • B01D2255/2061—Yttrium
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/20—Metals or compounds thereof
    • B01D2255/206—Rare earth metals
    • B01D2255/2065—Cerium
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/20—Metals or compounds thereof
    • B01D2255/207—Transition metals
    • B01D2255/20715—Zirconium
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/20—Metals or compounds thereof
    • B01D2255/209—Other metals
    • B01D2255/2092—Aluminium
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/40—Mixed oxides
    • B01D2255/407—Zr-Ce mixed oxides
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/50—Zeolites
    • B01D2255/502—Beta zeolites
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/90—Physical characteristics of catalysts
    • B01D2255/902—Multilayered catalyst
    • B01D2255/9022—Two layers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/90—Physical characteristics of catalysts
    • B01D2255/908—O2-storage component incorporated in the catalyst
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2258/00—Sources of waste gases
    • B01D2258/01—Engine exhaust gases
    • B01D2258/012—Diesel engines and lean burn gasoline engines
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/24—Stationary reactors without moving elements inside
    • B01J2219/2401—Reactors comprising multiple separate flow channels
    • B01J2219/2402—Monolithic-type reactors
    • B01J2219/2423—Separation means, e.g. membrane inside the reactor
    • B01J2219/2424—Wall-flow filter, e.g. adjacent cells closed alternatively at their end to force the reactant stream through the walls of the monolith
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/24—Stationary reactors without moving elements inside
    • B01J2219/2401—Reactors comprising multiple separate flow channels
    • B01J2219/2402—Monolithic-type reactors
    • B01J2219/2425—Construction materials
    • B01J2219/2427—Catalysts
    • B01J2219/2428—Catalysts coated on the surface of the monolith channels
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/24—Stationary reactors without moving elements inside
    • B01J2219/2401—Reactors comprising multiple separate flow channels
    • B01J2219/2402—Monolithic-type reactors
    • B01J2219/2425—Construction materials
    • B01J2219/2433—Construction materials of the monoliths
    • B01J2219/2438—Ceramics
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
    • F01N2510/00—Surface coverings
    • F01N2510/06—Surface coverings for exhaust purification, e.g. catalytic reaction
    • F01N2510/068—Surface coverings for exhaust purification, e.g. catalytic reaction characterised by the distribution of the catalytic coatings
    • F01N2510/0684—Surface coverings for exhaust purification, e.g. catalytic reaction characterised by the distribution of the catalytic coatings having more than one coating layer, e.g. multi-layered coatings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/0807—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents
    • F01N3/0821—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents combined with particulate filter
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
    • Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters

Definitions

  • Embodiments of the present invention are directed to diesel oxidation catalysts and methods of making thereof.
  • Oxidation catalysts comprising a precious metal dispersed on a refractory metal oxide support are known for use in treating the exhaust of diesel engines in order to convert both hydrocarbon and carbon monoxide gaseous pollutants by catalyzing the oxidation of these pollutants to carbon dioxide and water.
  • Such catalysts have been generally contained in units called diesel oxidation catalysts (DOC), or more simply catalytic converters, which are placed in the exhaust flow path from a diesel-powered engine to treat the exhaust before it vents to the atmosphere.
  • DOC diesel oxidation catalysts
  • the diesel oxidation catalysts are formed on ceramic or metallic substrate carriers (such as the flow-through monolith carrier, as described below) upon which one or more catalyst coating compositions are deposited.
  • ceramic or metallic substrate carriers such as the flow-through monolith carrier, as described below
  • oxidation catalysts that contain platinum group metals (which are typically dispersed on a refractory oxide support) promote the oxidation of nitric oxide (NO) to NO 2 .
  • Catalysts used to treat the exhaust of internal combustion engines are less effective during periods of relatively low temperature operation, such as the initial cold-start period of engine operation, because the engine exhaust is not at a temperature sufficiently high for efficient catalytic conversion of noxious components in the exhaust.
  • an adsorbent material which may be a zeolite, may be provided as part of a catalytic treatment system in order to adsorb gaseous pollutants, usually hydrocarbons, and retain them during the initial cold-start period. As the exhaust gas temperature increases, the adsorbed hydrocarbons are driven from the adsorbent and subjected to catalytic treatment at the higher temperature.
  • oxidation catalysts comprising a platinum group metal dispersed on a refractory metal oxide support are known for use in treating exhaust gas emissions from diesel engines.
  • Platinum (Pt) remains the most effective platinum group metal for oxidizing CO and HC in a DOC, after high temperature aging under lean conditions and in the presence of fuel sulfur.
  • Pd- incorporated catalysts offer advantages in stabilizing Pt at higher temperature aging (>700 °C) and lowering catalyst cost.
  • Pd based DOCs typically show higher light-off temperatures for oxidation of CO and HC, especially when used with HC storage materials, potentially causing a delay in HC and or CO light-off.
  • Pd containing DOCs may poison the activity of Pt to convert paraffins and/or oxidize NO and may also make the catalyst more susceptible to sulfur poisoning. These characteristics have typically prevented the use of Pd as an oxidation catalyst in lean bum operations especially for light duty diesel applications where engine
  • One or more embodiments of the invention are directed to catalytic articles for treating an exhaust gas stream containing hydrocarbons, CO and particulate matter.
  • the articles comprise a substrate having an inlet end and an outlet end defining an axial length.
  • a first washcoat layer on the substrate comprises greater than or equal to about 2% by weight palladium dispersed on a ceria support.
  • the second washcoat layer comprises a platinum group metal and a refractory metal oxide.
  • Additional embodiments of the invention are directed to emissions treatment systems comprising a diesel engine emitting an exhaust stream including hydrocarbons, CO and particulate matter.
  • the catalytic article comprising a substrate with a first washcoat layer and a second washcoat layer is downstream of and in flow communication with the diesel engine.
  • the first washcoat layer on the substrate comprises greater than or equal to about 2% by weight palladium dispersed on a ceria support.
  • the second washcoat layer is on the first washcoat layer.
  • the second washcoat layer comprises a platinum group metal and a refractory metal oxide.
  • FIG. 1 A substrate surface is coated with a first washcoat layer comprising palladium supported on ceria.
  • the palladium has a loading of greater than or equal to about 2% by weight.
  • the substrate is dried and calcined and then coated with a second washcoat layer comprising a platinum group metal and a refractory metal oxide. The substrate is then dried and calcined again.
  • the first washcoat layer comprises palladium in the range of about 2% to about 10% by weight. In specific embodiments, the first washcoat layer comprises about 4% palladium by weight. In some embodiments, the first washcoat layer comprises substantially no alumina. In one or more
  • the first washcoat comprises substantially no dopants.
  • the refractory metal oxide in the second washcoat layer comprises alumina.
  • the platinum group metal in the second washcoat layer comprises one or more of platinum and palladium supported on the refractory metal oxide. In specific embodiments, the platinum group metal in the second washcoat layer is present in the range of about 1 % to about 5% by weight. In some embodiments, the second washcoat layer further comprises a zeolite. In detailed embodiments, the zeolite comprises one or more of beta-zeolite, Y-zeolite and ZSM-5.
  • the substrate of specific embodiments is a flow-through substrate having a plurality of longitudinally extending passages formed by longitudinally extending walls bounding and defining said passages.
  • the substrate is a wall-flow filter having gas permeable walls formed into a plurality of axially extending channels, each channel having one end plugged with any pair of adjacent channels plugged at opposite ends thereof.
  • Figure 1 is a graph of the ceria crystallite size and the surface ratio of Pd to ceria as a function of the Pd loading in accordance with one or more embodiments of the invention
  • Figure 2 is a schematic view of a channel a catalytic article in
  • Figure 3 is a perspective view of a wall flow monolith in accordance with one or more embodiments of the invention.
  • Figure 4 is a partial cross-sectional view of a wall flow monolith for use with one or more embodiments of the invention.
  • Figure 5 is a partial cross-sectional view enlarged relative to Figure 3 and taken along a plane parallel to the end faces of the monolith of Figure 4, which shows an enlarged view of the gas flow passages shown in Figure 4;
  • Figure 6 shows a schematic view of the preparation of a catalytic article according to one or more embodiments of the invention.
  • Figure 7 shows an emissions treatment system in accordance with one or more embodiments of the invention
  • Figure 8 is a graph of the carbon monoxide light off temperature for catalysts in accordance with embodiments of the invention.
  • Figure 9 is a graph of the carbon monoxide conversion for various catalysts in accordance with embodiments of the invention.
  • Figure 10 is a graph of the carbon monoxide and propane conversions for various catalysts in accordance with embodiments of the invention.
  • exhaust stream and “engine exhaust stream” refer to the engine out effluent as well as to the effluent downstream of one or more other catalyst system components including but not limited to a diesel oxidation catalyst and/or soot filter.
  • Refractory metal oxides refer to alumina, silica, zirconia, tttania, ceria, and physical mixtures or chemical combinations thereof, including atomicaily doped combinations.
  • Platinum group metal components refer to platinum group metals in the Periodic Table of Elements or one of their oxides.
  • Rare earth metal components refer to one or more oxides of the lanthanum series defined in the Periodic Table of Elements, including lanthanum, cerium, praseodymium and neodymium.
  • Downstream refers to a position of a component in an exhaust gas stream in a path further away from the engine than the component preceding component.
  • Downstream refers to a position of a component in an exhaust gas stream in a path further away from the engine than the component preceding component.
  • upstream refers to a component that is located closer to the engine relate to another component.
  • An aspect of the invention pertains to a catalyst.
  • the catalyst may be disposed on a monolithic substrate as a washcoat layer.
  • Washcoat has its usual meaning in the art of a thin, adherent coating of a catalytic or other material applied to a refractory substrate, such as a honeycomb flow through monolith substrate or a filter substrate, which is sufficiently porous to permit the passage there through of the gas stream being treated.
  • a washcoat layer includes a compositionally distinct layer of material disposed on the surface of the monolithic substrate or an underlying washcoat layer.
  • a catalyst can contain one or more washcoat layers, and each washcoat layer can have unique chemical catalytic functions.
  • DOC diesel oxidation catalysts
  • OSC oxygen storage component
  • Embodiments of the invention describe superior low temperature activity of a pure ceria supported, high palladium concentration catalyst and its significant improvement of other palladium-OSC catalysts.
  • the high paliadium-ceria catalyst can be used alone or as a separate layer of a fully formulated catalyst to enhance the low temperature performance.
  • a pure ceria support is less stable than zirconia or other rare earth doped ceria upon hydrothermal aging at higher temperature (>700 °C).
  • Pd-CeO 2 at relatively low Pd loading shows much inferior activity than Pd-OSC for CO/HC oxidation.
  • the inventors have discovered that when the Pd concentration is increased to greater than or equal to about 3% by weight a dramatic mutual stabilization effect starts to occur which result in extremely high CO/HC light-off activity, and the activity improves even upon hydrothermal aging.
  • the high Pd-CeO 2 component can be employed in a separate layer from the Pt-Pd/Ai 2 O 3 component to avoid the negative interaction between Pt and CeO 2 .
  • the Pd-CeO 2 is located beneath the Pt-Pd/AI 2 O3 layer, so that the HC species, which could inhibit the Pd-CeO 2 function, can be oxidized and removed before reaching the Pd ⁇ CeO 2 .
  • a catalytic article 10 may comprise a substrate 2 having an inlet end 14 and an outlet end 16 defining an axial length L. A single channel 18 of the substrate 12 is shown.
  • a first washcoat layer 20 is on the substrate 12. The first washcoat layer 20 comprises greater than or equal to about 3% by weight palladium dispersed on a ceria support.
  • a second washcoat layer 22 is on the first washcoat layer 20. The second washcoat layer 22 comprises a platinum group metal and a refractory metal oxide. The amount of palladium in the first washcoat layer 20 can vary depending on the desired application and specific uses.
  • the first washcoat layer 20 comprises palladium in the range of about 2% to about 10% by weight. In some embodiments, the first washcoat layer 20 comprises palladium in the range of about 3% to about 6% by weight, in various embodiments, the first washcoat layer comprises about 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9% or 10% palladium by weight. In specific embodiments, the first washcoat layer 20 comprises about 4% palladium by weight. In various embodiments, the first washcoat layer 20 comprises palladium in an amount greater than about 2%, 4%, 5%, 6%, 7%, 8%, 9% or 10% by weight.
  • the first washcoat layer 20 comprises substantially no alumina.
  • substantially no alumina means that alumina has not been intentionally added to the first washcoat layer. It should be understood that alumina may migrate from layers above or below the first washcoat layer 20 without deviating from the meaning of substantially no alumina.
  • the activity of high % Pd-Ce0 2 catalyst can decrease when other dopants are present.
  • the first washcoat layer 20 comprises substantially no dopants.
  • the first washcoat layer 20 comprises substantially no dopants, individually or in combination, such as zirconium, lanthanum, praseodymium, samarium, neodymium, yttrium, titanium and/or silicon.
  • the second washcoat layer 22 composition differs from that of the first washcoat layer 20.
  • the second washcoat layer 22 has a refractory metal oxide comprising alumina. In these embodiments, it is expected that a small portion of the alumina will migrate into the first washcoat layer 20.
  • the platinum group metal in the second washcoat layer 22 of detailed embodiments comprises one or more of platinum and palladium supported on the refractory metal oxide, in specific embodiments, the platinum group metal of the second washcoat layer 22 is platinum and palladium.
  • the refractory metal oxide of the second washcoat layer 22 can be any suitable material known to those skilled in the art.
  • the refractory metal oxide of the second washcoat layer 22 comprises alumina.
  • the amount of the platinum group metal in the second washcoat layer 22 can be varied depending on the desired characteristics of the resultant catalytic article.
  • the platinum group metal in the second washcoat layer 22 is present in the range of about 1 % to about 5% by weight.
  • the second washcoat layer 22 of detailed embodiments further comprises a zeolite.
  • a zeolite Any suitable zeolite can be added and are known to those skilled in the art.
  • the zeolite comprises one or more of beta-zeolite, Y-zeolite and ZSM-5.
  • Any suitable substrate may be employed, such as a monolithic flow- through substrate and having a plurality of fine, parallel gas flow passages extending from an inlet to an outlet face of the substrate, such that passages are open to fluid flow.
  • the passages which are essentially straight paths from their fluid inlet to their fluid outlet, are defined by walls on which the catalytic material is coated as a
  • the flow passages of the monolithic substrate are thin-walled channels which can be of any suitable cross-sectional shape such as trapezoidal, rectangular, square, sinusoidal, hexagonal, oval, circular, etc. Such structures may contain from about 60 to about 1200 or more gas inlet openings (i.e., "cells") per square inch of cross section (cpsi).
  • cells gas inlet openings
  • the invention is not limited to a particular substrate type, material, or geometry.
  • Ceramic substrates may be made of any suitable or ceramic or metallic material.
  • Exemplary ceramic materials include but are not limited to: cordierite, cordierite-a alumina, silicon nitride, zircon mullite, spodumene, alumina-silica magnesia, zircon silicate, sillimanite, magnesium silicates, zircon, petalite, a alumina, aluminosilicates and the like.
  • Exemplary metallic supports include the heat resistant metals and metal alloys such as titanium and stainless steel as weli as other alloys in which iron is a substantial or major component.
  • FIGS 3 and 4 illustrate a wall flow filter substrate 50 which has a plurality of alternately blocked channels 52 and can serve as a particulate filter.
  • the passages are tubularly enclosed by the internal walls 53 of the filter substrate.
  • the plurality of axially extending channels are formed from gas permeable internal wails 53.
  • the substrate has an iniet end 54 and an outlet end 56. Alternate passages are plugged at the inlet end 54 with inlet plugs 58 and at the outlet end 56 with outlet plugs 60 to form opposing checkerboard patterns at the inlet 54 and outlet 56.
  • each channel 52 has one end plugged with any pair of adjacent channels plugged at opposite ends thereof.
  • the gas cannot pass back to the inlet side of walls because of inlet plugs 58. !f such substrate is utilized, the resulting system will be able to remove particulate matters along with gaseous pollutants.
  • Figure 5 shows a partial cross-sectional view of the wall flow filter in Figures 2 and 3.
  • the cross-sectional view is shown along a plane parallel to the end of the substrate 50.
  • the flow passages, or channels 52 are formed by the internal walls 53 and extend through the substrate 50 from the inlet end 54 to the outlet end 56.
  • the iniet plugs 58 and outlet plugs 60 are not shown.
  • the walls 53 are so dimensioned and configured that gas flow channels 52 have a substantially regular polygonal shape, substantially square in the illustrated embodiment, but with rounded corners in accordance with U.S. Pat. No. 4,335,023, issued Jun. 15, 1982 to J. C. Dettling et al.
  • the second washcoat layer 22 is coated over the first washcoat layer 20 as described herein.
  • an undercoat (not shown) can be applied to the substrate 12 beneath the first washcoat layer 20.
  • the carrier member include void spaces provided by the gas-flow channels 52, and the cross-sectional area of channels 52 and the thickness of the walls 53 defining the channels 52 will vary from one type of carrier member to another.
  • the weight of washcoat applied to such carriers will vary from case to case. Consequently, in describing the quantity of washcoat or catalytic metal component or other component of the composition, it is convenient to use units of weight of component per unit volume of catalyst carrier. Therefore, the units grams per cubic inch (“g/in 3 ”) and grams per cubic foot (“g/ft 3 ”) are used herein to mean the weight of a component per volume of the carrier member, including the volume of void spaces of the carrier member.
  • the concentration of platinum group metal is typically from about 10 to 200 g/ft 3 , 30 to 150 g/ft 3 , or even 50 to 120 g/ft 3 .
  • one or more embodiments of the invention are directed to methods of making a catalytic article.
  • a substrate 12 surface is coated with a first washcoat layer 20 comprising palladium supported on ceria.
  • the substrate 12 having an inlet end 14 and an outlet end 16 defining an axial length L.
  • a single channel 18 of the substrate 12 is shown for illustrative purposes. It should be understood that the substrate 12 may comprise a plurality of channels. In detailed embodiments, the substrate 12 has a plurality of channels 18 formed by axially extending gas permeable walls.
  • the palladium has a loading of greater than or equal to about 2% by weight.
  • the coated substrate 12 is then dried and calcined to fix the first washcoat layer 20 onto the substrate 12.
  • the coated substrate 12 is then coated with a second washcoat layer 22.
  • the second washcoat layer 22 comprises a platinum group metal and a refractory metal oxide.
  • the coated substrate 12 is then dried and calcined again to fix the second washcoat layer 22 onto the substrate12.
  • Some embodiments of the second washcoat layer 22 have been described herein.
  • additional embodiments of the invention are directed to emissions treatment systems 70.
  • One or more embodiments of the system 70 comprise a diesel engine 71 emitting an exhaust stream including hydrocarbons, CO and particulate matter.
  • a diesel oxidation catalytic article 10, as described throughout, is positioned downstream of and in flow communication with the diesel engine 71.
  • the catalytic article 10 has an inlet end and an outlet end defining an axial length.
  • the exhaust gas stream exiting the diesel engine 71 passes through the catalytic article 10 where the NOx, CO and hydrocarbons are oxidized.
  • the exhaust stream exiting the catalytic article 10 can then exit the treatment system 70 through, for example, the tailpipe 73 and be expelled to the atmosphere.
  • the samples were dried at 1 10 °C and calcined at 450 °C in air. After hydrothermal aging at 750 °C for 20 hours, the samples were evaluated for CO and HC light-off activity on a lab reactor.
  • the light-off gas mixture consisted of 2000 ppm CO, 100 ppm C 3 H 6 , 100 ppm C3H8, 50 ppm Toluene, 00 ppm NO, 12% O 2 and 5% H 2 O.
  • FIG 8 shows T 5 o, i.e. the temperature at which 50% conversion is achieved (lower T 50 « higher activity) for the various samples.
  • T 50 o the temperature at which 50% conversion is achieved
  • 0.5%Pd/CeO 2 sample showed the highest T 50 ⁇ 215 °C
  • the activity of the Pd/CeO 2 series increases drastically with Pd loading, and the highest activity is observed when Pd% is > 4% ( ⁇ 86 °C). This observation was consistent with the Pd-CeO 2 synergy demonstrated in Figure 1.
  • a series of 2-4%Pd loaded CeO 2 and OSC (45%CeO 2 -55%ZrO 2 ) samples were prepared by incipient wetness impregnation of support materials with Pd(NH 3 ) 4 (NO 3 ) 2 solution. The samples were dried at 110 °C and calcined at 450 °C in air. Each powder sample was made into a slurry and milled to particle size Dgo ⁇ 12 ⁇ , it was then mixed with a pre-milled ⁇ -alumina slurry at 50:50 dry gain ratio, then coated onto a flow through monolith substrate. The ⁇ -alumina served as a binder material for better washcoat adhesion. The total washcoat was 1.5 g/in 3 , and Pd loading was 26 g/ft 3 for 2%Pd/support or 52 g/ft 3 for 4%Pd/support respectively.
  • the 5%Y-CeO 2 support was prepared by impregnating Y(NO 3 )3 solution onto CeO 2 followed with drying and calcination.
  • a reference Pt-Pd/AI 2 O 3 catalyst at 70 g/ft 3 PGM loading and 2/1 Pt/Pd ratio was also prepared for comparison.
  • the Pt and Pd precursor solutions were co-impregnated onto the alumina support followed with drying and calcination.
  • the subsequent slurry and coating procedures were similar to those of Pd/CeO 2 catalysts.
  • the coated catalysts were aged on a diesel engine at 750 °C for 20 hours, and measured for CO/HC light-off activities on a lab reactor.
  • the light-off gas mixture consisted of 1400 ppm CO, 100 ppm C 3 H 6 , 50 ppm toluene, 100 ppm NO, 5% CO 2l 10% O 2 and 7% H 2 O.
  • the space velocity was 50,000 h " .
  • Figure 9 shows a comparison of the CO light-off data.
  • the 2%Pd/CeO 2 catalyst showed >50 °C improvement in T 50
  • the 4%Pd/CeO2 showed further improvement than the 2%Pd/CeO 2 catalyst, particulariy in the higher temperature region (i.e. Teo).
  • the CO T 50 of 2%Pd/CeO 2 increased by ⁇ 20 °C when 5%Y was introduced to CeO 2 . Similar decay in activity was observed when other elements such as Zr or La were introduced.
  • the 2-4%Pd/CeO 2 catalysts Compared to the Pt-Pd/AI 2 O 3 reference catalyst at much higher PGM loading, the 2-4%Pd/CeO 2 catalysts also showed higher activity at lower temperature region up to 140 °C, confirming the advantages of high Pd/Ce0 2 component for low temperature CO/HC conversion, which could significant!y benefit the emission abatement during cold start.
  • Layered catalysts were prepared by using 2-6%Pd/Ce02 in the bottom layer and PtPd/Al20 3 +p-zeolite in the top layer. Given fixed PGM loading and ratio, the PGM distribution in the bottom and top layers was adjusted to achieve maximal overall activity. As described Example 2, 2-6%Pd/Ce0 2 in the bottom layer made greater contribution during cold-start emission, whereas the Pt-Pd/Al203 component in the top layer was more effective for emission conversion at higher temperatures. Zeolites were separated from the Pd/Ce0 2 component at all times to avoid negative impact on Pd.
  • the catalyst consisted of 8%Pd/Ce0 2 or 8%Pd/OSC (45%Ce0 2 - 55%Zr0 2 ) in the bottom layer (washcoat loading was 1 g/in 3 , Pd loading was 138 g/ft 3 ), and PVAI2O3+ ⁇ -zeolite in the top layer (washcoat loading was 0.75 g/in3, Pt loading was 8g/ft 3 ).
  • the catalysts were aged and tested under the same condition as in Example 2. The CO and C 3 H 6 light-off data are shown in Figure 0.
  • the catalyst with the 8%Pd/CeO 2 bottom coat showed 20-30 °C lower T 50 .

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Organic Chemistry (AREA)
  • Materials Engineering (AREA)
  • Combustion & Propulsion (AREA)
  • Health & Medical Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • General Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Analytical Chemistry (AREA)
  • Environmental & Geological Engineering (AREA)
  • Biomedical Technology (AREA)
  • Toxicology (AREA)
  • General Health & Medical Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Catalysts (AREA)
  • Exhaust Gas Treatment By Means Of Catalyst (AREA)
  • Exhaust Gas After Treatment (AREA)

Abstract

Diesel oxidation catalysts, catalytic articles, methods of making catalytic articles, emissions treatment systems and methods of treating an exhaust gas stream using the catalytic articles for the treatment of exhaust gas emissions, such as the oxidation of unburned hydrocarbons (HC) and carbon monoxide (CO) are described. Specific catalytic articles comprising a substrate with a first washcoat layer comprising greater than or equal to about 2% by weight palladium dispersed on a ceria support and a second washcoat layer comprising a platinum group metal and a refractory metal oxide are described.

Description

DIESEL OXIDATION CATALYST ARTICLES AND METHODS OF MAKING AND
USING
BACKGROUND
[0001] Embodiments of the present invention are directed to diesel oxidation catalysts and methods of making thereof.
[0002] Operation of lean burn engines, e.g., diesel engines and lean burn gasoline engines, provide the user with excellent fuel economy and have very low emissions of gas phase hydrocarbons and carbon monoxide due to their operation at high air/fuel ratios under fuel lean conditions. Diesel engines, in particular, also offer significant advantages over gasoline engines in terms of their fuel economy, durability and their ability to generate high torque at low speed.
[0003] From the standpoint of emissions, however, diesel engines present problems more severe than their spark-ignition counterparts. Emission problems relate to particulate matter (PM), nitrogen oxides (NOx), unburned hydrocarbons (HC) and carbon monoxide (CO). NOx is a term used to describe various chemicai species of nitrogen oxides, including nitrogen monoxide (NO) and nitrogen dioxide (NO2), among others. NO is of concern because it is believed to undergo a process known as photo-chemical smog formation, through a series of reactions in the presence of sunlight and hydrocarbons, and is significant contributor to acid rain. NO2 on the other hand has a high potential as an oxidant and is a strong lung irritant. Particulates (PM) are a!so connected to respiratory problems. As engine operation modifications are made to reduce particulates and unburned hydrocarbons on diesel engines, the NOx emissions tend to increase.
[0004] Oxidation catalysts comprising a precious metal dispersed on a refractory metal oxide support are known for use in treating the exhaust of diesel engines in order to convert both hydrocarbon and carbon monoxide gaseous pollutants by catalyzing the oxidation of these pollutants to carbon dioxide and water. Such catalysts have been generally contained in units called diesel oxidation catalysts (DOC), or more simply catalytic converters, which are placed in the exhaust flow path from a diesel-powered engine to treat the exhaust before it vents to the atmosphere. Typically, the diesel oxidation catalysts are formed on ceramic or metallic substrate carriers (such as the flow-through monolith carrier, as described below) upon which one or more catalyst coating compositions are deposited. In addition to the
conversion of gaseous HC, CO and the SOF fraction of particulate matter, oxidation catalysts that contain platinum group metals (which are typically dispersed on a refractory oxide support) promote the oxidation of nitric oxide (NO) to NO2.
[0005] Catalysts used to treat the exhaust of internal combustion engines are less effective during periods of relatively low temperature operation, such as the initial cold-start period of engine operation, because the engine exhaust is not at a temperature sufficiently high for efficient catalytic conversion of noxious components in the exhaust. To this end, an adsorbent material, which may be a zeolite, may be provided as part of a catalytic treatment system in order to adsorb gaseous pollutants, usually hydrocarbons, and retain them during the initial cold-start period. As the exhaust gas temperature increases, the adsorbed hydrocarbons are driven from the adsorbent and subjected to catalytic treatment at the higher temperature.
[0006] As discussed above, oxidation catalysts comprising a platinum group metal dispersed on a refractory metal oxide support are known for use in treating exhaust gas emissions from diesel engines. Platinum (Pt) remains the most effective platinum group metal for oxidizing CO and HC in a DOC, after high temperature aging under lean conditions and in the presence of fuel sulfur. Nevertheless, Pd- incorporated catalysts offer advantages in stabilizing Pt at higher temperature aging (>700 °C) and lowering catalyst cost. However, Pd based DOCs typically show higher light-off temperatures for oxidation of CO and HC, especially when used with HC storage materials, potentially causing a delay in HC and or CO light-off. Pd containing DOCs may poison the activity of Pt to convert paraffins and/or oxidize NO and may also make the catalyst more susceptible to sulfur poisoning. These characteristics have typically prevented the use of Pd as an oxidation catalyst in lean bum operations especially for light duty diesel applications where engine
temperatures remain below 250 °C for most driving conditions. It would be desirable to improve upon one or more of the aforementioned limitations.
SUMMARY [0007] One or more embodiments of the invention are directed to catalytic articles for treating an exhaust gas stream containing hydrocarbons, CO and particulate matter. The articles comprise a substrate having an inlet end and an outlet end defining an axial length. A first washcoat layer on the substrate comprises greater than or equal to about 2% by weight palladium dispersed on a ceria support. A second washcoat layer on the first washcoat layer. The second washcoat layer comprises a platinum group metal and a refractory metal oxide.
[0008] Additional embodiments of the invention are directed to emissions treatment systems comprising a diesel engine emitting an exhaust stream including hydrocarbons, CO and particulate matter. The catalytic article comprising a substrate with a first washcoat layer and a second washcoat layer is downstream of and in flow communication with the diesel engine. The first washcoat layer on the substrate comprises greater than or equal to about 2% by weight palladium dispersed on a ceria support. The second washcoat layer is on the first washcoat layer. The second washcoat layer comprises a platinum group metal and a refractory metal oxide.
[0009] Further embodiments of the invention are directed to methods of making a catalytic article. A substrate surface is coated with a first washcoat layer comprising palladium supported on ceria. The palladium has a loading of greater than or equal to about 2% by weight. The substrate is dried and calcined and then coated with a second washcoat layer comprising a platinum group metal and a refractory metal oxide. The substrate is then dried and calcined again.
[0010] In detailed embodiments, the first washcoat layer comprises palladium in the range of about 2% to about 10% by weight. In specific embodiments, the first washcoat layer comprises about 4% palladium by weight. In some embodiments, the first washcoat layer comprises substantially no alumina. In one or more
embodiments, the first washcoat comprises substantially no dopants. In detailed embodiments, the refractory metal oxide in the second washcoat layer comprises alumina.
[0011] In detailed embodiments, the platinum group metal in the second washcoat layer comprises one or more of platinum and palladium supported on the refractory metal oxide. In specific embodiments, the platinum group metal in the second washcoat layer is present in the range of about 1 % to about 5% by weight. In some embodiments, the second washcoat layer further comprises a zeolite. In detailed embodiments, the zeolite comprises one or more of beta-zeolite, Y-zeolite and ZSM-5.
[0012] The substrate of specific embodiments is a flow-through substrate having a plurality of longitudinally extending passages formed by longitudinally extending walls bounding and defining said passages. In one or more embodiments, the substrate is a wall-flow filter having gas permeable walls formed into a plurality of axially extending channels, each channel having one end plugged with any pair of adjacent channels plugged at opposite ends thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 is a graph of the ceria crystallite size and the surface ratio of Pd to ceria as a function of the Pd loading in accordance with one or more embodiments of the invention;
[0014] Figure 2 is a schematic view of a channel a catalytic article in
accordance with one or more embodiments of the invention;
[0015] Figure 3 is a perspective view of a wall flow monolith in accordance with one or more embodiments of the invention;
[0016] Figure 4 is a partial cross-sectional view of a wall flow monolith for use with one or more embodiments of the invention;
[0017] Figure 5 is a partial cross-sectional view enlarged relative to Figure 3 and taken along a plane parallel to the end faces of the monolith of Figure 4, which shows an enlarged view of the gas flow passages shown in Figure 4;
[0018] Figure 6 shows a schematic view of the preparation of a catalytic article according to one or more embodiments of the invention; and
[00 9] Figure 7 shows an emissions treatment system in accordance with one or more embodiments of the invention; [0020] Figure 8 is a graph of the carbon monoxide light off temperature for catalysts in accordance with embodiments of the invention;
[0021] Figure 9 is a graph of the carbon monoxide conversion for various catalysts in accordance with embodiments of the invention; and
[0022] Figure 10 is a graph of the carbon monoxide and propane conversions for various catalysts in accordance with embodiments of the invention.
DETAILED DESCRIPTION
[0023] Before describing several exemplary embodiments of the invention, it is to be understood that the invention is not limited to the details of construction or process steps set forth in the following description. The invention is capable of other embodiments and of being practiced or being carried out in various ways.
[0024] Where they appear herein, the terms "exhaust stream" and "engine exhaust stream" refer to the engine out effluent as well as to the effluent downstream of one or more other catalyst system components including but not limited to a diesel oxidation catalyst and/or soot filter.
[0025] The following terms shall have, for the purposes of this application, the respective meanings set forth below.
[0026] "Refractory metal oxides" refer to alumina, silica, zirconia, tttania, ceria, and physical mixtures or chemical combinations thereof, including atomicaily doped combinations.
[0027] "Platinum group metal components" refer to platinum group metals in the Periodic Table of Elements or one of their oxides.
[0028] "Rare earth metal components" refer to one or more oxides of the lanthanum series defined in the Periodic Table of Elements, including lanthanum, cerium, praseodymium and neodymium.
[0029] "Flow communication" means that the components and/or conduits are adjoined such that exhaust gases or other fluids can flow between the components and/or conduits. [0030] "Downstream" refers to a position of a component in an exhaust gas stream in a path further away from the engine than the component preceding component. For example, when a diesel particulate filter is referred to as downstream from a diesel oxidation catalyst, exhaust gas emanating from the engine in an exhaust conduit flows through the diesel oxidation catalyst before flowing through the diesel particulate filter. Thus, "upstream" refers to a component that is located closer to the engine relate to another component.
[0031] An aspect of the invention pertains to a catalyst. According to one or more embodiments, the catalyst may be disposed on a monolithic substrate as a washcoat layer. "Washcoat" has its usual meaning in the art of a thin, adherent coating of a catalytic or other material applied to a refractory substrate, such as a honeycomb flow through monolith substrate or a filter substrate, which is sufficiently porous to permit the passage there through of the gas stream being treated. As used herein and as described in Ronald M.Heck and Robert J. Farrauto, Catalytic Air Pollution Control, New York: Wiley-lnterscience, 2002, pp. 18-19, a washcoat layer includes a compositionally distinct layer of material disposed on the surface of the monolithic substrate or an underlying washcoat layer. A catalyst can contain one or more washcoat layers, and each washcoat layer can have unique chemical catalytic functions.
[0032] A major function of diesel oxidation catalysts (DOC) is to convert carbon monoxide and hydrocarbons at relatively low temperature, particularly during engine cold start. Incorporating palladium with an oxygen storage component (OSC) into the DOC has been shown to significantly improve the CO/HC light-off activity.
Embodiments of the invention describe superior low temperature activity of a pure ceria supported, high palladium concentration catalyst and its significant improvement of other palladium-OSC catalysts. The high paliadium-ceria catalyst can be used alone or as a separate layer of a fully formulated catalyst to enhance the low temperature performance.
[0033] A pure ceria support is less stable than zirconia or other rare earth doped ceria upon hydrothermal aging at higher temperature (>700 °C). As a result, after such aging, Pd-CeO2 at relatively low Pd loading (<1%) shows much inferior activity than Pd-OSC for CO/HC oxidation. However, the inventors have discovered that when the Pd concentration is increased to greater than or equal to about 3% by weight a dramatic mutual stabilization effect starts to occur which result in extremely high CO/HC light-off activity, and the activity improves even upon hydrothermal aging.
[0034] Without being bound by any particular theory of operation, it is believed that the high activity probably comes from a combination of several factors: (1) nearly atomic dispersion of Pd on the CeO2 surface and readily available Pd°; (2) strong stabilization of CeO2 crystallite by Pd {At >4% loading) from sintering at higher temperature; and (3) activation by steam which is unique to Pd-OSC component and is enhanced by the Pd-CeO2 synergy. Evidence for strong Pd-CeO2 synergy is demonstrated in Figure 1. The CeO2 crystallite size and surface Pd concentration as a function of Pd loading on CeO2 were measured on samples that were aged at 750 °C/20 h in 0% steam air. The systematic decrease in CeO2 crystallite size and increase in surface Pd/CeO2 with increasing Pd loading suggests a mutual
stabilization effect between CeO2 and Pd upon hydrothermal aging. On the other hand, such behavior is not observed on any doped-CeO2 supported Pd catalysts, i.e. surface Pd concentration does not increase with increasing Pd loading. Differently from zirconia-supported Pd catalysts, Pd-CeO2 catalyst appears stable under light-off conditions and does not suffer from run-to-run deactivations. An advantage of 3-8% Pd-CeO2 to Pd/OSC remained after engine aging, a 24 °C improvement in CO light-off was observed. The high activity of 3-8% Pd-CeO2 catalyst decreases dramatically when other dopants, such as zirconium or lanthanum are present. It is believed that this is due to the loss of Pd-CeO2 interaction which may be important for low
temperature activity.
[0035] The high Pd-CeO2 component can be employed in a separate layer from the Pt-Pd/Ai2O3 component to avoid the negative interaction between Pt and CeO2. In specific embodiments, the Pd-CeO2 is located beneath the Pt-Pd/AI2O3 layer, so that the HC species, which could inhibit the Pd-CeO2 function, can be oxidized and removed before reaching the Pd~CeO2.
[0036] Accordingly, one or more embodiments of the invention pertain to catalytic articles for treating an exhaust gas stream containing hydrocarbons, CO and particulate matter. With reference to Figure 2, a catalytic article 10 may comprise a substrate 2 having an inlet end 14 and an outlet end 16 defining an axial length L. A single channel 18 of the substrate 12 is shown. A first washcoat layer 20 is on the substrate 12. The first washcoat layer 20 comprises greater than or equal to about 3% by weight palladium dispersed on a ceria support. A second washcoat layer 22 is on the first washcoat layer 20. The second washcoat layer 22 comprises a platinum group metal and a refractory metal oxide. The amount of palladium in the first washcoat layer 20 can vary depending on the desired application and specific uses. In one or more embodiments, the first washcoat layer 20 comprises palladium in the range of about 2% to about 10% by weight. In some embodiments, the first washcoat layer 20 comprises palladium in the range of about 3% to about 6% by weight, in various embodiments, the first washcoat layer comprises about 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9% or 10% palladium by weight. In specific embodiments, the first washcoat layer 20 comprises about 4% palladium by weight. In various embodiments, the first washcoat layer 20 comprises palladium in an amount greater than about 2%, 4%, 5%, 6%, 7%, 8%, 9% or 10% by weight.
[0037] In specific embodiments, the first washcoat layer 20 comprises substantially no alumina. As used in this specification and the appended claims, the term "substantially no alumina" means that alumina has not been intentionally added to the first washcoat layer. It should be understood that alumina may migrate from layers above or below the first washcoat layer 20 without deviating from the meaning of substantially no alumina.
[0038] As has been previously described, the activity of high % Pd-Ce02 catalyst can decrease when other dopants are present. In detailed embodiments, the first washcoat layer 20 comprises substantially no dopants. According to specific embodiments, the first washcoat layer 20 comprises substantially no dopants, individually or in combination, such as zirconium, lanthanum, praseodymium, samarium, neodymium, yttrium, titanium and/or silicon.
[0039] In one or more embodiments, the second washcoat layer 22 composition differs from that of the first washcoat layer 20. For example, in some embodiments, the second washcoat layer 22 has a refractory metal oxide comprising alumina. In these embodiments, it is expected that a small portion of the alumina will migrate into the first washcoat layer 20.
[0040] The platinum group metal in the second washcoat layer 22 of detailed embodiments comprises one or more of platinum and palladium supported on the refractory metal oxide, in specific embodiments, the platinum group metal of the second washcoat layer 22 is platinum and palladium.
[0041] The refractory metal oxide of the second washcoat layer 22 can be any suitable material known to those skilled in the art. In specific embodiments, the refractory metal oxide of the second washcoat layer 22 comprises alumina.
[0042] The amount of the platinum group metal in the second washcoat layer 22 can be varied depending on the desired characteristics of the resultant catalytic article. In detailed embodiments, the platinum group metal in the second washcoat layer 22 is present in the range of about 1 % to about 5% by weight.
[0043] The second washcoat layer 22 of detailed embodiments further comprises a zeolite. Any suitable zeolite can be added and are known to those skilled in the art. In specific embodiments, the zeolite comprises one or more of beta-zeolite, Y-zeolite and ZSM-5.
The Substrate
[0044] Any suitable substrate may be employed, such as a monolithic flow- through substrate and having a plurality of fine, parallel gas flow passages extending from an inlet to an outlet face of the substrate, such that passages are open to fluid flow. The passages, which are essentially straight paths from their fluid inlet to their fluid outlet, are defined by walls on which the catalytic material is coated as a
"washcoat" so that the gases flowing through the passages contact the catalytic material. The flow passages of the monolithic substrate are thin-walled channels which can be of any suitable cross-sectional shape such as trapezoidal, rectangular, square, sinusoidal, hexagonal, oval, circular, etc. Such structures may contain from about 60 to about 1200 or more gas inlet openings (i.e., "cells") per square inch of cross section (cpsi). However, it will be understood that the invention is not limited to a particular substrate type, material, or geometry.
[0045] Ceramic substrates may be made of any suitable or ceramic or metallic material. Exemplary ceramic materials include but are not limited to: cordierite, cordierite-a alumina, silicon nitride, zircon mullite, spodumene, alumina-silica magnesia, zircon silicate, sillimanite, magnesium silicates, zircon, petalite, a alumina, aluminosilicates and the like. Exemplary metallic supports include the heat resistant metals and metal alloys such as titanium and stainless steel as weli as other alloys in which iron is a substantial or major component.
[0046] Figures 3 and 4 illustrate a wall flow filter substrate 50 which has a plurality of alternately blocked channels 52 and can serve as a particulate filter. The passages are tubularly enclosed by the internal walls 53 of the filter substrate. The plurality of axially extending channels are formed from gas permeable internal wails 53. The substrate has an iniet end 54 and an outlet end 56. Alternate passages are plugged at the inlet end 54 with inlet plugs 58 and at the outlet end 56 with outlet plugs 60 to form opposing checkerboard patterns at the inlet 54 and outlet 56. Thus, each channel 52 has one end plugged with any pair of adjacent channels plugged at opposite ends thereof. A gas stream enters through the unplugged channel inlet 64, is stopped by outlet plug 60 and diffuses through channel walls 53 (which are porous) to the outlet end 56. The gas cannot pass back to the inlet side of walls because of inlet plugs 58. !f such substrate is utilized, the resulting system will be able to remove particulate matters along with gaseous pollutants.
[0047] Figure 5 shows a partial cross-sectional view of the wall flow filter in Figures 2 and 3. The cross-sectional view is shown along a plane parallel to the end of the substrate 50. It can be seen from Figure 5 that the flow passages, or channels 52, are formed by the internal walls 53 and extend through the substrate 50 from the inlet end 54 to the outlet end 56. The iniet plugs 58 and outlet plugs 60 are not shown. The walls 53 are so dimensioned and configured that gas flow channels 52 have a substantially regular polygonal shape, substantially square in the illustrated embodiment, but with rounded corners in accordance with U.S. Pat. No. 4,335,023, issued Jun. 15, 1982 to J. C. Dettling et al. The first washcoat layer 20, which in the art and sometimes herein is referred to as a "washcoat", is adhered or coated onto the walls 53 of the substrate 12. The second washcoat layer 22 is coated over the first washcoat layer 20 as described herein. In some embodiments, an undercoat (not shown) can be applied to the substrate 12 beneath the first washcoat layer 20.
[0048] As shown in Figure 5, the carrier member include void spaces provided by the gas-flow channels 52, and the cross-sectional area of channels 52 and the thickness of the walls 53 defining the channels 52 will vary from one type of carrier member to another. Similarly, the weight of washcoat applied to such carriers will vary from case to case. Consequently, in describing the quantity of washcoat or catalytic metal component or other component of the composition, it is convenient to use units of weight of component per unit volume of catalyst carrier. Therefore, the units grams per cubic inch ("g/in3") and grams per cubic foot ("g/ft3") are used herein to mean the weight of a component per volume of the carrier member, including the volume of void spaces of the carrier member.
[0049] When the composition is disposed on a refractory oxide substrate, e.g., a flow through honeycomb substrate, the concentration of platinum group metal is typically from about 10 to 200 g/ft3, 30 to 150 g/ft3, or even 50 to 120 g/ft3.
Method of Preparing a Catalyst
[0050] With reference to Figure 6, one or more embodiments of the invention are directed to methods of making a catalytic article. A substrate 12 surface is coated with a first washcoat layer 20 comprising palladium supported on ceria. The substrate 12 having an inlet end 14 and an outlet end 16 defining an axial length L. A single channel 18 of the substrate 12 is shown for illustrative purposes. It should be understood that the substrate 12 may comprise a plurality of channels. In detailed embodiments, the substrate 12 has a plurality of channels 18 formed by axially extending gas permeable walls. The palladium has a loading of greater than or equal to about 2% by weight. The coated substrate 12 is then dried and calcined to fix the first washcoat layer 20 onto the substrate 12. Some embodiments of the first washcoat layer 20 have been described herein. [0051] The coated substrate 12 is then coated with a second washcoat layer 22. The second washcoat layer 22 comprises a platinum group metal and a refractory metal oxide. The coated substrate 12 is then dried and calcined again to fix the second washcoat layer 22 onto the substrate12. Some embodiments of the second washcoat layer 22 have been described herein.
Emissions Treatment System
[0052] With reference to Figure 7, additional embodiments of the invention are directed to emissions treatment systems 70. One or more embodiments of the system 70 comprise a diesel engine 71 emitting an exhaust stream including hydrocarbons, CO and particulate matter. A diesel oxidation catalytic article 10, as described throughout, is positioned downstream of and in flow communication with the diesel engine 71. The catalytic article 10 has an inlet end and an outlet end defining an axial length. The exhaust gas stream exiting the diesel engine 71 passes through the catalytic article 10 where the NOx, CO and hydrocarbons are oxidized. The exhaust stream exiting the catalytic article 10 can then exit the treatment system 70 through, for example, the tailpipe 73 and be expelled to the atmosphere.
EXAMPLES Example 1
[0053] A series of Pd loaded CeO2l OSC (45%CeO2-55%ZrO2), or ZrO2 samples at different Pd concentrations were prepared by incipient wetness
impregnation of support materials with a Pd(NH3)<s(NO3)2 solution. The samples were dried at 1 10 °C and calcined at 450 °C in air. After hydrothermal aging at 750 °C for 20 hours, the samples were evaluated for CO and HC light-off activity on a lab reactor. The light-off gas mixture consisted of 2000 ppm CO, 100 ppm C3H6, 100 ppm C3H8, 50 ppm Toluene, 00 ppm NO, 12% O2 and 5% H2O.
[0054] Figure 8 shows T5o, i.e. the temperature at which 50% conversion is achieved (lower T50 « higher activity) for the various samples. Although 0.5%Pd/CeO2 sample showed the highest T50 {215 °C), the activity of the Pd/CeO2 series increases drastically with Pd loading, and the highest activity is observed when Pd% is > 4% (< 86 °C). This observation was consistent with the Pd-CeO2 synergy demonstrated in Figure 1. On the other hand, on the OSC (45%CeO2-55%ZrO2) or ZrO2 supports, the CO light-off T5o (1 10-130 °C) did not respond to Pd loading and appeared much higher than the 4-8%Pd/CeO2 samples at equivalent Pd loading.
Example 2,
[0055] A series of 2-4%Pd loaded CeO2 and OSC (45%CeO2-55%ZrO2) samples were prepared by incipient wetness impregnation of support materials with Pd(NH3)4(NO3)2 solution. The samples were dried at 110 °C and calcined at 450 °C in air. Each powder sample was made into a slurry and milled to particle size Dgo < 12 μηη, it was then mixed with a pre-milled γ-alumina slurry at 50:50 dry gain ratio, then coated onto a flow through monolith substrate. The γ-alumina served as a binder material for better washcoat adhesion. The total washcoat was 1.5 g/in3, and Pd loading was 26 g/ft3 for 2%Pd/support or 52 g/ft3 for 4%Pd/support respectively.
[0056] The 5%Y-CeO2 support was prepared by impregnating Y(NO3)3 solution onto CeO2 followed with drying and calcination. A reference Pt-Pd/AI2O3 catalyst at 70 g/ft3 PGM loading and 2/1 Pt/Pd ratio was also prepared for comparison. In this case, the Pt and Pd precursor solutions were co-impregnated onto the alumina support followed with drying and calcination. The subsequent slurry and coating procedures were similar to those of Pd/CeO2 catalysts. The coated catalysts were aged on a diesel engine at 750 °C for 20 hours, and measured for CO/HC light-off activities on a lab reactor. The light-off gas mixture consisted of 1400 ppm CO, 100 ppm C3H6, 50 ppm toluene, 100 ppm NO, 5% CO2l 10% O2 and 7% H2O. The space velocity was 50,000 h" .
[0057] Figure 9 shows a comparison of the CO light-off data. Compared to the 2%Pd/OSC catalyst, the 2%Pd/CeO2 catalyst showed >50 °C improvement in T50, the 4%Pd/CeO2 showed further improvement than the 2%Pd/CeO2 catalyst, particulariy in the higher temperature region (i.e. Teo). The CO T50 of 2%Pd/CeO2 increased by ~ 20 °C when 5%Y was introduced to CeO2. Similar decay in activity was observed when other elements such as Zr or La were introduced. Compared to the Pt-Pd/AI2O3 reference catalyst at much higher PGM loading, the 2-4%Pd/CeO2 catalysts also showed higher activity at lower temperature region up to 140 °C, confirming the advantages of high Pd/Ce02 component for low temperature CO/HC conversion, which could significant!y benefit the emission abatement during cold start.
Example 3.
[0058] Layered catalysts were prepared by using 2-6%Pd/Ce02 in the bottom layer and PtPd/Al203+p-zeolite in the top layer. Given fixed PGM loading and ratio, the PGM distribution in the bottom and top layers was adjusted to achieve maximal overall activity. As described Example 2, 2-6%Pd/Ce02 in the bottom layer made greater contribution during cold-start emission, whereas the Pt-Pd/Al203 component in the top layer was more effective for emission conversion at higher temperatures. Zeolites were separated from the Pd/Ce02 component at all times to avoid negative impact on Pd. In the examples, the catalyst consisted of 8%Pd/Ce02 or 8%Pd/OSC (45%Ce02- 55%Zr02) in the bottom layer (washcoat loading was 1 g/in3, Pd loading was 138 g/ft3), and PVAI2O3+ β-zeolite in the top layer (washcoat loading was 0.75 g/in3, Pt loading was 8g/ft3). The catalysts were aged and tested under the same condition as in Example 2. The CO and C3H6 light-off data are shown in Figure 0. The catalyst with the 8%Pd/CeO2 bottom coat showed 20-30 °C lower T50.
[0059] Reference throughout this specification to "one embodiment," "certain embodiments," "one or more embodiments" or "an embodiment" means that a particular feature, structure, material, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. Thus, the appearances of the phrases such as "in one or more embodiments," "in certain embodiments," "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily referring to the same embodiment of the invention. Furthermore, the particular features, structures, materials, or
characteristics may be combined in any suitable manner in one or more embodiments. The order of description of the above method should not be considered limiting, and methods may use the described operations out of order or with omissions or additions.
[0060] ft is to be understood that the above description is intended to be illustrative, and not restrictive. Many other embodiments will be apparent to those of ordinary skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

p
WO 2012/071421 PCT/US2011/061860
16
What is c!aimeci is:
1 , A catalytic article for treating an exhaust gas stream containing hydrocarbons, CO and particulate matter, the article comprising:
a substrate having an inlet end and an outlet end defining an axial length;
a first washcoat layer on the substrate comprising greater than or equal to about 2% by weight palladium dispersed on a ceria support; and
a second washcoat layer on the first washcoat layer, the second washcoat layer comprising a platinum group metal and a refractory metal oxide.
2. The catalytic article of claim , wherein the first washcoat layer comprises
palladium in the range of about 2% to about 10% by weight.
3. The catalytic article of claim 1 , wherein the first washcoat layer comprises
about 4% palladium by weight.
4. The catalytic article of any of claims 1-3, wherein the first washcoat layer
comprises substantially no alumina.
5. The catalytic article of any of claims 1 -4, wherein the first washcoat comprises substantially no dopants.
6. The catalytic article of any of claims 1-5, wherein the refractory metal oxide in the second washcoat layer comprises alumina.
7. The catalytic article of any of claims 1-6, wherein the platinum group metal in the second washcoat layer comprises one or more of platinum and palladium supported on the refractory metal oxide.
8. The catalytic article of any of claims 1-7, wherein the platinum group metal in the second washcoat layer is present in the range of about 1% to about 5% by weight. ΡΔΤΡΝΙΤ
WO 2012/071421 PCT/US2011/061860
17
9. The catalytic article of any of claims 1-8, wherein the second washcoat layer further comprises a zeolite,
10. The catalytic article of claim 9, wherein the zeolite is selected from beta-zeolite, Y-zeolite and ZSM-5.
11. The catalytic article of claim 1 , wherein the substrate is a flow-through
substrate having a plurality of longitudinally extending passages formed by longitudinally extending walls bounding and defining said passages.
12. The catalytic article of ciaim 1 , wherein the substrate is a wall-flow filter having gas permeable walls formed into a plurality of axially extending channels, each channel having one end plugged with any pair of adjacent channels plugged at opposite ends thereof.
13. An emissions treatment system comprising;
a diesel engine emitting an exhaust stream including hydrocarbons, CO and particulate matter; and
the catalytic article of any of claims 1-12.
14. A method of making a catalytic article according to any of claims 1-12
comprising:
coating a substrate surface with a first washcoat layer comprising palladium supported on ceria, the palladium having a loading of greater than or equal to about 2% by weight;
drying and calcining the substrate;
coating the substrate with a second washcoat layer comprising a platinum group metal and a refractory metal oxide; and
drying and calcining the substrate.
PCT/US2011/061860 2010-11-24 2011-11-22 Diesel oxidation catalyst articles and methods of making and using Ceased WO2012071421A2 (en)

Priority Applications (8)

Application Number Priority Date Filing Date Title
EP11843705.2A EP2643082B1 (en) 2010-11-24 2011-11-22 Diesel oxidation catalyst articles and methods of making and using
CA2818860A CA2818860A1 (en) 2010-11-24 2011-11-22 Diesel oxidation catalyst articles and methods of making and using
JP2013541025A JP5843880B2 (en) 2010-11-24 2011-11-22 Diesel oxidation catalyst body and production and use thereof
CN2011800637118A CN103313787A (en) 2010-11-24 2011-11-22 Diesel oxidation catalyst articles and methods of making and using
MX2013005886A MX342674B (en) 2010-11-24 2011-11-22 Diesel oxidation catalyst articles and methods of making and using.
BR112013013008-3A BR112013013008B1 (en) 2010-11-24 2011-11-22 CATALYTIC ARTICLE, EMISSION TREATMENT SYSTEM, AND METHOD FOR MANUFACTURING CATALYTIC ARTICLE
KR1020137016164A KR101862814B1 (en) 2010-11-24 2011-11-22 Diesel oxidation catalyst articles and methods of making and using
ZA2013/04549A ZA201304549B (en) 2010-11-24 2013-06-20 Diesel oxidation catalyst articles and methods of making and using

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US12/954,257 2010-11-24
US12/954,257 US8668877B2 (en) 2010-11-24 2010-11-24 Diesel oxidation catalyst articles and methods of making and using

Publications (2)

Publication Number Publication Date
WO2012071421A2 true WO2012071421A2 (en) 2012-05-31
WO2012071421A3 WO2012071421A3 (en) 2012-07-19

Family

ID=46063019

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2011/061860 Ceased WO2012071421A2 (en) 2010-11-24 2011-11-22 Diesel oxidation catalyst articles and methods of making and using

Country Status (11)

Country Link
US (1) US8668877B2 (en)
EP (1) EP2643082B1 (en)
JP (1) JP5843880B2 (en)
KR (1) KR101862814B1 (en)
CN (2) CN103313787A (en)
BR (1) BR112013013008B1 (en)
CA (1) CA2818860A1 (en)
MX (1) MX342674B (en)
MY (1) MY161590A (en)
WO (1) WO2012071421A2 (en)
ZA (1) ZA201304549B (en)

Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012156883A1 (en) * 2011-05-13 2012-11-22 Basf Se Catalyzed soot filter with layered design
JP2014117702A (en) * 2012-12-13 2014-06-30 Hyundai Motor Company Co Ltd Diesel oxidation catalyst
KR101507325B1 (en) 2013-12-20 2015-03-31 희성촉매 주식회사 A catalyst member for purifying exhuast gas and washcoat therefor
US9138725B2 (en) 2013-03-12 2015-09-22 Basf Corporation Catalyst materials for NO oxidation
US9643161B2 (en) 2013-05-17 2017-05-09 Johnson Matthey Public Limited Company Oxidation catalyst for a compression ignition engine
WO2018015259A1 (en) 2016-07-19 2018-01-25 Umicore Ag & Co. Kg Diesel oxidizing catalytic converter
EP3450015A1 (en) 2017-08-31 2019-03-06 Umicore Ag & Co. Kg Palladium-zeolite-based passive nitrogen oxide adsorber catalyst for exhaust gas treatment
EP3450016A1 (en) 2017-08-31 2019-03-06 Umicore Ag & Co. Kg Palladium-zeolite-based passive nitrogen oxide adsorber catalyst for exhaust gas treatment
EP3449999A1 (en) 2017-08-31 2019-03-06 Umicore Ag & Co. Kg Passive nitric oxide adsorber
WO2019042883A1 (en) 2017-08-31 2019-03-07 Umicore Ag & Co. Kg PALLADIUM ZEOLITE BASED PASSIVE STAINOXIDE ADSORBER CATALYST FOR EXHAUST PURIFICATION
WO2019042884A1 (en) 2017-08-31 2019-03-07 Umicore Ag & Co. Kg USE OF A PALLADIUM PLATINUM ZEOLITE-BASED CATALYST AS A PASSIVE STAIN OXIDE ADSORBER FOR EMISSION CONTROL
EP3459617A1 (en) 2017-09-22 2019-03-27 Umicore Ag & Co. Kg Particle filter with integrated catalytic functions
WO2019077111A1 (en) 2017-10-20 2019-04-25 Umicore Ag & Co. Kg Passive nitrogen oxide adsorber catalyst
WO2019134958A1 (en) 2018-01-05 2019-07-11 Umicore Ag & Co. Kg Passive nitrogen oxide adsorber
EP2758168B1 (en) 2011-09-23 2019-07-31 Basf Se Diesel oxidation catalyst with layered structure containing ceria composition as palladium support material for enhanced hc and co gas conversion
EP3613503A1 (en) 2018-08-22 2020-02-26 Umicore Ag & Co. Kg Passive nitrogen oxide adsorber
EP3616792A1 (en) 2018-08-28 2020-03-04 Umicore Ag & Co. Kg Nitrogen oxide storage catalyst
WO2020099253A1 (en) 2018-11-16 2020-05-22 Umicore Ag & Co. Kg Low temperature nitrogen oxide adsorber
WO2020144195A1 (en) 2019-01-08 2020-07-16 Umicore Ag & Co. Kg Passive nitrogen oxide adsorber having oxidation-catalytically active function
EP3815780A1 (en) 2019-10-30 2021-05-05 Umicore Ag & Co. Kg Diesel oxidation catalyst
EP3865209A1 (en) 2020-02-17 2021-08-18 UMICORE AG & Co. KG Diesel oxidation catalyst
EP4302862A1 (en) 2022-07-06 2024-01-10 Johnson Matthey Public Limited Company Lean nox trap

Families Citing this family (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0715836B2 (en) 1987-11-11 1995-02-22 ホシデン株式会社 Fluorescent light control device
CA2844732A1 (en) * 2011-08-10 2013-02-14 Clean Diesel Technologies, Inc. Palladium solid solution catalyst and methods of making
GB201220912D0 (en) 2012-11-21 2013-01-02 Johnson Matthey Plc Oxidation catalyst for treating the exhaust gas of a compression ignition engine
EP2772302A1 (en) * 2013-02-27 2014-09-03 Umicore AG & Co. KG Hexagonal oxidation catalyst
CN105188931A (en) * 2013-03-14 2015-12-23 巴斯夫公司 Catalytic article with segregated washcoat and methods of making same
DE102014110811B4 (en) * 2013-07-30 2022-09-01 Johnson Matthey Plc CATALYST ARTICLE FOR TREATMENT OF EXHAUST GAS
KR20160048134A (en) * 2013-08-28 2016-05-03 존슨 맛쎄이 퍼블릭 리미티드 컴파니 Co slip catalyst and method of using
US20150078975A1 (en) * 2013-09-16 2015-03-19 International Engine Intellectual Property Company, Llc Natural gas engine aftertreatment system
US9744529B2 (en) * 2014-03-21 2017-08-29 Basf Corporation Integrated LNT-TWC catalyst
RU2017134081A (en) * 2015-03-03 2019-04-03 Басф Корпорейшн NOx ADSORPTION CATALYST, METHODS AND SYSTEMS
EP3271070A4 (en) * 2015-03-19 2018-11-21 BASF Corporation Automotive catalysts with palladium supported in an alumina-free layer
GB2546164A (en) * 2015-09-30 2017-07-12 Johnson Matthey Plc Gasoline particulate filter
KR20180102196A (en) * 2016-02-03 2018-09-14 바스프 코포레이션 Multi-layer catalyst composition for internal combustion engine
MX2018015865A (en) * 2016-06-17 2019-04-22 Basf Corp PALADIO DIESEL OXIDATION CATALYST.
EP3493906A1 (en) * 2016-08-05 2019-06-12 Johnson Matthey Public Limited Company Diesel oxidation catalyst having a capture region for sulfur containing impurities
CN110382110A (en) * 2017-03-06 2019-10-25 巴斯夫公司 In conjunction with platinum group metal and copper-alumina spinel catalyst
JP7700050B2 (en) * 2019-05-22 2025-06-30 ビーエーエスエフ モバイル エミッションズ カタリスツ エルエルシー Integrated emission control system including diesel oxidation catalyst and low temperature NOx adsorber
US11614013B2 (en) * 2020-02-21 2023-03-28 Johnson Matthey Public Limited Company Twc catalysts for gasoline engine exhaust gas treatments
CN113457674B (en) * 2021-05-31 2022-12-27 广西科技大学 Improve Pt-CeO 2 Method for low temperature activity and durability of catalyst oxidation reaction

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4335023A (en) 1980-01-24 1982-06-15 Engelhard Corporation Monolithic catalyst member and support therefor
US5177041A (en) 1990-06-20 1993-01-05 Nippon Shokubai Co., Ltd. Catalyst for purifying exhaust gas from diesel engines
EP0622107A2 (en) 1993-04-28 1994-11-02 Toyota Jidosha Kabushiki Kaisha Exhaust gas purifying catalyst in diesel engines
US20030153453A1 (en) 2000-08-08 2003-08-14 Cataler Corporation Catalyst for purifying exhaust gas
US20070104623A1 (en) 2005-11-10 2007-05-10 Dettling Joseph C Diesel particulate filters having ultra-thin catalyzed oxidation coatings
US20100166629A1 (en) 2008-12-29 2010-07-01 Basf Catalysts Llc Oxidation Catalyst With Low CO and HC Light-Off and Systems and Methods
US20100180582A1 (en) 2009-01-16 2010-07-22 Basf Catalysts Llc Diesel Oxidation Catalyst With Layer Structure for Improved Hydrocarbon Conversion
US20100183490A1 (en) 2009-01-16 2010-07-22 BASF Catalystic LLC Diesel oxidation catalyst and use thereof in diesel and advanced combustion diesel engine systems
US20100257843A1 (en) 2009-04-08 2010-10-14 Basf Catalysts Llc Zoned Catalysts for Diesel Applications

Family Cites Families (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0621539B2 (en) * 1986-12-04 1994-03-23 キヤタラ−工業株式会社 Patty unit for burning catalyst filter
GB9226434D0 (en) 1992-12-18 1993-02-10 Johnson Matthey Plc Catalyst
ES2131980T3 (en) * 1996-11-11 1999-08-01 Degussa EXHAUST GAS PURIFYING CATALYST WITH BETTER CONVERSION CAPACITY FOR HYDROCARBONS
US6348430B1 (en) * 1997-06-20 2002-02-19 Degussa Ag Exhaust gas treatment catalyst for internal combustion engines with two catalytically active layers on a carrier structure
DE19726322A1 (en) 1997-06-20 1998-12-24 Degussa Exhaust gas cleaning catalytic converter for internal combustion engines with two catalytically active layers on a support body
JP2003062465A (en) 2001-08-28 2003-03-04 Toyota Motor Corp Catalyst
JP4161633B2 (en) * 2002-07-29 2008-10-08 トヨタ自動車株式会社 Particulate purification catalyst
EP1537304B1 (en) * 2002-09-13 2007-02-28 Johnson Matthey Public Limited Company Compression ignition engine and exhaust system therefor
JP3991908B2 (en) 2003-04-08 2007-10-17 日産自動車株式会社 Exhaust gas purification method
JP2006007117A (en) 2004-06-25 2006-01-12 Ne Chemcat Corp Exhaust gas purification structure and exhaust gas purification method using the structure
GB2406803A (en) 2004-11-23 2005-04-13 Johnson Matthey Plc Exhaust system comprising exotherm-generating catalyst
JP2007285295A (en) 2006-03-24 2007-11-01 Ngk Insulators Ltd Exhaust emission control system
US7576031B2 (en) 2006-06-09 2009-08-18 Basf Catalysts Llc Pt-Pd diesel oxidation catalyst with CO/HC light-off and HC storage function
GB0620883D0 (en) * 2006-10-20 2006-11-29 Johnson Matthey Plc Exhaust system for a lean-burn internal combustion engine
ATE464458T1 (en) * 2007-02-23 2010-04-15 Umicore Ag & Co Kg CATALYTICALLY ACTIVATED DIESEL PARTICLE FILTER WITH AMMONIA BLOCKING EFFECT
JP5122195B2 (en) * 2007-07-17 2013-01-16 本田技研工業株式会社 NOx purification catalyst
GB0808427D0 (en) * 2008-05-09 2008-06-18 Johnson Matthey Plc Apparatus
US8211392B2 (en) * 2009-01-16 2012-07-03 Basf Corporation Diesel oxidation catalyst composite with layer structure for carbon monoxide and hydrocarbon conversion

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4335023A (en) 1980-01-24 1982-06-15 Engelhard Corporation Monolithic catalyst member and support therefor
US5177041A (en) 1990-06-20 1993-01-05 Nippon Shokubai Co., Ltd. Catalyst for purifying exhaust gas from diesel engines
EP0622107A2 (en) 1993-04-28 1994-11-02 Toyota Jidosha Kabushiki Kaisha Exhaust gas purifying catalyst in diesel engines
US20030153453A1 (en) 2000-08-08 2003-08-14 Cataler Corporation Catalyst for purifying exhaust gas
US20070104623A1 (en) 2005-11-10 2007-05-10 Dettling Joseph C Diesel particulate filters having ultra-thin catalyzed oxidation coatings
US20100166629A1 (en) 2008-12-29 2010-07-01 Basf Catalysts Llc Oxidation Catalyst With Low CO and HC Light-Off and Systems and Methods
US20100180582A1 (en) 2009-01-16 2010-07-22 Basf Catalysts Llc Diesel Oxidation Catalyst With Layer Structure for Improved Hydrocarbon Conversion
US20100183490A1 (en) 2009-01-16 2010-07-22 BASF Catalystic LLC Diesel oxidation catalyst and use thereof in diesel and advanced combustion diesel engine systems
US20100257843A1 (en) 2009-04-08 2010-10-14 Basf Catalysts Llc Zoned Catalysts for Diesel Applications

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP2643082A4

Cited By (38)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012156883A1 (en) * 2011-05-13 2012-11-22 Basf Se Catalyzed soot filter with layered design
EP2758168B1 (en) 2011-09-23 2019-07-31 Basf Se Diesel oxidation catalyst with layered structure containing ceria composition as palladium support material for enhanced hc and co gas conversion
EP2758168B2 (en) † 2011-09-23 2022-11-16 Basf Se Diesel oxidation catalyst with layered structure containing ceria composition as palladium support material for enhanced hc and co gas conversion
JP2014117702A (en) * 2012-12-13 2014-06-30 Hyundai Motor Company Co Ltd Diesel oxidation catalyst
US9138725B2 (en) 2013-03-12 2015-09-22 Basf Corporation Catalyst materials for NO oxidation
US9643161B2 (en) 2013-05-17 2017-05-09 Johnson Matthey Public Limited Company Oxidation catalyst for a compression ignition engine
US11794169B2 (en) 2013-05-17 2023-10-24 Johnson Matthey Public Limited Company Oxidation catalyst for a compression ignition engine
KR101507325B1 (en) 2013-12-20 2015-03-31 희성촉매 주식회사 A catalyst member for purifying exhuast gas and washcoat therefor
WO2015093809A1 (en) * 2013-12-20 2015-06-25 희성촉매 주식회사 Catalytic member for purifying exhaust gases, and washcoat
WO2018015259A1 (en) 2016-07-19 2018-01-25 Umicore Ag & Co. Kg Diesel oxidizing catalytic converter
US11052378B2 (en) 2016-07-19 2021-07-06 Umicore Ag & Co. Kg Diesel oxidizing catalytic converter
EP3450015A1 (en) 2017-08-31 2019-03-06 Umicore Ag & Co. Kg Palladium-zeolite-based passive nitrogen oxide adsorber catalyst for exhaust gas treatment
WO2019042884A1 (en) 2017-08-31 2019-03-07 Umicore Ag & Co. Kg USE OF A PALLADIUM PLATINUM ZEOLITE-BASED CATALYST AS A PASSIVE STAIN OXIDE ADSORBER FOR EMISSION CONTROL
WO2019042883A1 (en) 2017-08-31 2019-03-07 Umicore Ag & Co. Kg PALLADIUM ZEOLITE BASED PASSIVE STAINOXIDE ADSORBER CATALYST FOR EXHAUST PURIFICATION
US11141717B2 (en) 2017-08-31 2021-10-12 Umicore Ag & Co. Kg Palladium/zeolite-based passive nitrogen oxide adsorber catalyst for purifying exhaust gas
EP3449999A1 (en) 2017-08-31 2019-03-06 Umicore Ag & Co. Kg Passive nitric oxide adsorber
US11161100B2 (en) 2017-08-31 2021-11-02 Umicore Ag & Co. Kg Use of a palladium/platinum/zeolite-based catalyst as passive nitrogen oxide adsorber for purifying exhaust gas
EP3450016A1 (en) 2017-08-31 2019-03-06 Umicore Ag & Co. Kg Palladium-zeolite-based passive nitrogen oxide adsorber catalyst for exhaust gas treatment
EP3459617A1 (en) 2017-09-22 2019-03-27 Umicore Ag & Co. Kg Particle filter with integrated catalytic functions
WO2019077111A1 (en) 2017-10-20 2019-04-25 Umicore Ag & Co. Kg Passive nitrogen oxide adsorber catalyst
US10711674B2 (en) 2017-10-20 2020-07-14 Umicore Ag & Co. Kg Passive nitrogen oxide adsorber catalyst
WO2019134958A1 (en) 2018-01-05 2019-07-11 Umicore Ag & Co. Kg Passive nitrogen oxide adsorber
WO2020039015A1 (en) 2018-08-22 2020-02-27 Umicore Ag & Co. Kg Passive nitrogen oxide adsorber
EP3613503A1 (en) 2018-08-22 2020-02-26 Umicore Ag & Co. Kg Passive nitrogen oxide adsorber
EP3616792A1 (en) 2018-08-28 2020-03-04 Umicore Ag & Co. Kg Nitrogen oxide storage catalyst
US11376550B2 (en) 2018-08-28 2022-07-05 Umicore Ag & Co. Kg Nitrogen oxide storage catalyst
WO2020043578A1 (en) 2018-08-28 2020-03-05 Umicore Ag & Co. Kg Nitrogen oxide storage catalyst
US11439952B2 (en) 2018-11-16 2022-09-13 Umicore Ag & Co. Kg Low temperature nitrogen oxide adsorber
WO2020099253A1 (en) 2018-11-16 2020-05-22 Umicore Ag & Co. Kg Low temperature nitrogen oxide adsorber
WO2020144195A1 (en) 2019-01-08 2020-07-16 Umicore Ag & Co. Kg Passive nitrogen oxide adsorber having oxidation-catalytically active function
US11772077B2 (en) 2019-01-08 2023-10-03 Umicore Ag & Co. Kg Passive nitrogen oxide adsorber having oxidation-catalytically active function
EP3815780A1 (en) 2019-10-30 2021-05-05 Umicore Ag & Co. Kg Diesel oxidation catalyst
WO2021084054A1 (en) 2019-10-30 2021-05-06 Umicore Ag & Co. Kg Diesel oxidation catalyst
US12515208B2 (en) 2019-10-30 2026-01-06 Umicore Ag & Co. Kg Diesel oxidation catalyst
WO2021165280A1 (en) 2020-02-17 2021-08-26 Umicore Ag & Co. Kg Diesel oxidation catalyst
EP3865209A1 (en) 2020-02-17 2021-08-18 UMICORE AG & Co. KG Diesel oxidation catalyst
EP4302862A1 (en) 2022-07-06 2024-01-10 Johnson Matthey Public Limited Company Lean nox trap
WO2024009072A1 (en) 2022-07-06 2024-01-11 Johnson Matthey Public Limited Company Lean nox trap

Also Published As

Publication number Publication date
MX2013005886A (en) 2013-12-06
BR112013013008A2 (en) 2017-03-21
CA2818860A1 (en) 2012-05-31
WO2012071421A3 (en) 2012-07-19
KR20140002678A (en) 2014-01-08
EP2643082B1 (en) 2017-05-10
EP2643082A4 (en) 2014-07-30
ZA201304549B (en) 2014-08-27
US8668877B2 (en) 2014-03-11
BR112013013008B1 (en) 2019-08-13
CN107262094A (en) 2017-10-20
KR101862814B1 (en) 2018-05-30
CN103313787A (en) 2013-09-18
JP2014504202A (en) 2014-02-20
JP5843880B2 (en) 2016-01-13
MY161590A (en) 2017-04-28
US20120124975A1 (en) 2012-05-24
EP2643082A2 (en) 2013-10-02
MX342674B (en) 2016-10-07

Similar Documents

Publication Publication Date Title
US8668877B2 (en) Diesel oxidation catalyst articles and methods of making and using
US9120077B2 (en) Surface-coated zeolite materials for diesel oxidation applications
CN102711960B (en) Zoned catalytic soot filter
CA2818754C (en) Advanced catalyzed soot filters and method of making and using the same
US7947238B2 (en) Oxidation catalyst with low CO and HC light-off and systems and methods
US8449852B1 (en) Diesel oxidation catalysts, systems and methods of treatment
KR101962504B1 (en) Pt-pd diesel oxidation catalyst with co/hc light-off and hc storage function
KR20160098399A (en) Manganese-containing diesel oxidation catalyst
EP3942162A1 (en) Layered tri-metallic catalytic article and method of manufacturing the catalytic article
WO2012099868A2 (en) Three way conversion catalyst with alumina-free rhodium layer
EP3634626A2 (en) Catalytic article and exhaust gas treatment systems
WO2018224651A2 (en) Catalytic article and exhaust gas treatment systems
US20220258137A1 (en) Catalyst substrate comprising radially-zoned coating
KR102843951B1 (en) Adjustable NOx adsorbent

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 11843705

Country of ref document: EP

Kind code of ref document: A2

ENP Entry into the national phase

Ref document number: 2818860

Country of ref document: CA

ENP Entry into the national phase

Ref document number: 2013541025

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

WWE Wipo information: entry into national phase

Ref document number: MX/A/2013/005886

Country of ref document: MX

ENP Entry into the national phase

Ref document number: 20137016164

Country of ref document: KR

Kind code of ref document: A

REEP Request for entry into the european phase

Ref document number: 2011843705

Country of ref document: EP

WWE Wipo information: entry into national phase

Ref document number: 2011843705

Country of ref document: EP

REG Reference to national code

Ref country code: BR

Ref legal event code: B01A

Ref document number: 112013013008

Country of ref document: BR

ENP Entry into the national phase

Ref document number: 112013013008

Country of ref document: BR

Kind code of ref document: A2

Effective date: 20130524