Oxidation catalyst comprising platinum group metal and base metal or metalloid oxide

Abstract

The present disclosure relates to oxidation catalyst compositions comprising a platinum group metal (PGM) component comprising palladium, platinum, or a combination thereof; a first oxide selected from oxides of cerium, silicon, iron, cobalt, zinc, chromium, molybdenum, nickel, tungsten, magnesium, antimony, tin, lead, yttrium, and combinations thereof; and a first refractory metal oxide support material; catalytic articles; and exhaust gas treatment systems, as well as methods of making and using such oxidation catalyst compositions.

Description

[0001] This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 071,584, filed on August 28, 2020, the contents of which are incorporated herein by reference in their entirety.

[0002] This disclosure relates to catalyst compositions suitable for treating exhaust streams from internal combustion engines, such as diesel engines, as well as catalytic articles and systems comprising such compositions and methods of using them.

[0003] Environmental regulations governing emissions from internal combustion engines are becoming increasingly stringent worldwide. Lean-burn engines, such as diesel engines, offer excellent fuel economy due to their operation under lean-fuel conditions with a high air / fuel ratio. However, diesel engines also emit particulate matter (PM), unburned hydrocarbons (HC) and oxygenated hydrocarbon derivatives (such as formaldehyde), carbon monoxide (CO), and nitrogen oxides (NOx). x The exhaust emissions of NO x This describes various chemical substances containing nitrogen oxides, including nitric oxide and nitrogen dioxide. The two main components of particulate matter in exhaust gases are the soluble organic fraction (SOF) and the insoluble carbonaceous soot fraction. SOF condenses on the soot in the form of a layer and typically originates from unburned diesel fuel and lubricating oil. Depending on the exhaust gas temperature, SOF can exist in diesel exhaust gases as vapor or aerosol (i.e., fine droplets of liquid condensate). Soot is primarily composed of carbon particles.

[0004] Oxidation catalysts comprising one or more platinum group metals (PGMs) dispersed on a refractory metal oxide support, such as alumina, are known to be used to treat diesel engine exhaust gases to convert these pollutants by catalytically oxidizing hydrocarbons, oxygenated hydrocarbon derivatives, and carbon monoxide gaseous pollutants to carbon dioxide and water. Such catalysts are typically contained in a unit called a diesel oxidation catalyst (DOC), which is placed in the exhaust gas flow path from the diesel engine to treat the exhaust gases before they are released into the atmosphere. Typically, diesel oxidation catalysts are formed on a ceramic or metal substrate on which one or more catalyst coating compositions are deposited. In addition to converting gaseous HC and CO emissions and particulate matter (SOF portion), oxidation catalysts containing one or more PGMs also promote the oxidation of NO to NO2. Catalysts are typically categorized by their ignition temperature or the temperature at which 50% conversion is achieved (also known as T). 50 Defined by ).

[0005] As regulations concerning vehicle emissions become more stringent, emissions control during cold starts is becoming increasingly important. While a variety of harmful exhaust components need to be considered, given the increasingly stringent regulations, NO xParticularly interesting. For the 2024 model year, the NO. 1 for heavy-duty diesel vehicles... x Emission regulations require tailpipe NO x Less than or equal to 0.1 g / HP-Hr. Furthermore, the 2024 model year emissions regulations further require vehicles to meet formaldehyde emission standards.

[0006] Various treatment methods have been used to treat NO-containing substances. x The waste gas mixture is treated to reduce air pollution. One type of treatment involves selective catalytic reduction (SCR) processes, in which ammonia or ammonia precursors are used as reducing agents. In selective reduction processes, the use of stoichiometric reducing agents enables a high degree of nitrogen oxide removal, resulting in the formation of primarily nitrogen gas and vapor.

[0007] Furthermore, catalysts used to treat internal combustion engine exhaust gases are less efficient during relatively low-temperature operating cycles, such as the initial cold start cycle of engine operation, because the engine exhaust gases are not at a sufficiently high temperature (i.e., below 200°C) to effectively catalyze the conversion of harmful components in the exhaust gases. At these low temperatures, exhaust gas treatment systems typically do not demonstrate sufficient effectiveness in treating hydrocarbon (HC) emissions, oxygenated hydrocarbon derivatives (e.g., HCHO), and nitrogen oxides (NOx). x Catalytic activity for NO emissions and / or carbon monoxide (CO) emissions. Typically, catalytic modules such as SCR catalyst modules are very effective at temperatures above 200°C in removing NO. x It is converted to N2, but does not exhibit sufficient activity in the lower temperature range (<200°C), such as the activity found during cold starts or prolonged low-speed city driving. During the initial engine start-up, including the first 400 seconds of operation, the exhaust temperature at the SCR inlet is below 170°C, at which temperature the SCR has not yet fully activated. Therefore, nearly 70% of the system output NO is... x Emissions are emitted during the first 500 seconds of engine operation.

[0008] Currently, there is a disconnect between DOC and SCR performance during cold starts (i.e., the performance of DOC before SCR takes effect). x (Conversion performance), because DOC operates at temperatures lower than SCR. One way to address this disconnect is by enhancing the NO2 / NO2 ratio of DOC at temperatures below 250°C. x Performance improvements were sought to enhance SCR performance at low temperatures. Previous attempts to address these issues involved using Mn-doped alumina to stabilize Pt, thereby generating a favorable NO2 / NO2 / NO2 ratio. xPerformance. See, for example, BASF's U.S. Patent Application Publications US2015 / 0165422 and US2015 / 0165423, which are incorporated herein by reference. However, while the Mn-doped alumina / Pt catalysts disclosed therein provide stable NO2 / NO x Performance, but it does not provide the enhanced low-temperature NO2 / NO2 / NO2 ratio required for downstream SCR catalysts. x Performance. Therefore, there is a need in the art for catalyst compositions that enhance the performance of DOC+SCR systems during low-temperature operation and effectively oxidize formaldehyde during low-temperature operation.

[0009] This disclosure generally provides oxidation catalyst compositions that exhibit enhanced hydrocarbon conversion and NO2 formation relative to conventional oxidation catalysts and demonstrate recovery from sulfur poisoning. Surprisingly, it has been found that, in certain embodiments of this disclosure, oxidation catalyst compositions comprising platinum group metals (PGMs) including palladium and / or platinum, certain base metal or metal-like oxides, and refractory metal oxide support materials promote NO2 formation at temperatures comparable to those for oxidizing carbon monoxide (CO), exhibit enhanced hydrocarbon conversion (HC), and oxidize oxygenated hydrocarbon derivatives such as formaldehyde.

[0010] Therefore, in a first aspect, an oxidation catalyst composition for an exhaust gas treatment system including a compression-ignition internal combustion engine is provided, the composition comprising a platinum group metal (PGM) component including palladium, platinum, or combinations thereof; a first oxide selected from cerium, silicon, iron, cobalt, zinc, chromium, molybdenum, nickel, tungsten, magnesium, antimony, tin, lead, yttrium, and combinations thereof; and a first refractory metal oxide support material.

[0011] In some implementations, the first oxide is selected from oxides of yttrium and silicon.

[0012] In some embodiments, the amount of the first oxide contained in the oxidation catalyst composition is from about 1% to about 40% by weight, based on the weight of the first refractory metal oxide support material.

[0013] In some embodiments, the first refractory metal oxide support material comprises about 5% to about 99% by weight of zirconium oxide, based on the weight of the first refractory metal oxide support material.

[0014] In some embodiments, the first refractory metal oxide carrier material comprises about 1% by weight to about 99% by weight of zirconium oxide, titanium, or aluminum, based on the weight of the first refractory metal oxide carrier material.

[0015] In some embodiments, the first refractory metal oxide support material comprises about 20% to about 99% by weight of zirconium oxide, based on the weight of the zirconium oxide. In some embodiments, the zirconium oxide is doped with lanthanum, and the amount of lanthanum, based on the weight of the zirconium oxide, is about 0.1% to about 40% by weight (e.g., about 1% to about 40% by weight).

[0016] In some embodiments, the amount of the first oxide contained in the oxidation catalyst composition is from about 1% to about 30% by weight, or from about 5% to about 20% by weight, based on the weight of the first refractory metal oxide support material.

[0017] In some embodiments, palladium is loaded on the first refractory metal oxide support in an amount of 0% to 10% by weight, based on the weight of the first refractory metal oxide support; platinum is loaded on the first refractory metal oxide support in an amount of 0% to 10% by weight, based on the weight of the first refractory metal oxide support; and at least one of platinum or palladium is present in an amount of about 0.1% by weight or greater, based on the weight of the first refractory metal oxide support.

[0018] In some embodiments, the PGM component comprises palladium and platinum. In some embodiments, the weight ratio of palladium to platinum is from about 100 to about 0.01 (e.g., from about 100 to about 0.05). In some embodiments, the weight ratio of palladium to platinum is from about 1 to about 0.01, from about 1 to about 0.05, or from about 0.5 to about 0.1.

[0019] In some implementations, the PGM component is essentially composed of palladium.

[0020] In some implementations, the PGM component is essentially composed of platinum.

[0021] In some embodiments, the oxidation catalyst composition further comprises a second refractory metal oxide support material. In some embodiments, the second refractory metal oxide support material comprises alumina, silica, zirconium oxide, titanium dioxide, cerium dioxide, or combinations thereof. In some embodiments, the second refractory metal oxide support material comprises alumina. In some embodiments, the second refractory metal oxide support material comprises zirconium oxide. In some embodiments, the zirconium oxide is doped with lanthanum, and the amount of lanthanum, based on the weight of zirconium oxide, is from about 0.1 wt% to about 40 wt% (e.g., from about 1 wt% to about 40 wt%).

[0022] In some embodiments, the first oxide is loaded on a first refractory metal oxide support material, and the PGM component is loaded on a second refractory metal oxide support material.

[0023] In some embodiments, the PGM component is loaded onto the second refractory metal oxide support material in an amount of about 0.5% to about 10% by weight, based on the weight of the second refractory metal oxide support material.

[0024] In some embodiments, the first oxide is loaded on a first refractory metal oxide support material, and the amount, based on the weight of the first refractory metal oxide support material, is from about 1 wt% to about 40 wt% in terms of oxide content; and the PGM component is loaded on a second refractory metal oxide support material, wherein the second refractory metal oxide support material is selected from (e.g., selected from the group consisting of) alumina, silica-doped alumina, titanium dioxide, titanium dioxide-doped alumina, zirconium-doped alumina, zirconium oxide, and zirconium oxide doped with about 0.1 wt% to about 40 wt% (e.g., about 1 wt% to about 40 wt%) of lanthanum oxide based on the weight of zirconium oxide.

[0025] In some embodiments, zirconium oxide is doped with about 0.1% to about 40% (e.g., about 1% to about 40%) of lanthanum oxide, based on the weight of zirconium oxide.

[0026] In some embodiments, the first refractory metal oxide support material further comprises cerium dioxide, in an amount of about 1% to about 50% by weight, based on the weight of the first refractory metal oxide support material.

[0027] In some embodiments, the oxidation catalyst composition is essentially copper-free.

[0028] In another aspect, a catalyst article is provided comprising a substrate having an inlet end and an outlet end having a defined total length, and a catalytic coating disposed on at least a portion thereof, the catalytic coating comprising a first substrate coating and a second substrate coating, wherein the first substrate coating comprises a first oxide and a first refractory metal oxide support material, wherein the first oxide is selected from oxides of cerium, silicon, iron, cobalt, zinc, chromium, molybdenum, nickel, tungsten, magnesium, antimony, tin, lead, yttrium, and combinations thereof; and the first oxide is loaded on the first refractory metal oxide support material; the second substrate coating comprises a platinum group metal (PGM) component including palladium, platinum, or combinations thereof and a second refractory metal oxide support material, wherein the PGM component is loaded on the second refractory metal oxide support material.

[0029] In some embodiments, the amount of the first oxide contained in the catalyst article is from about 1% to about 40% by weight, based on the weight of the first refractory metal oxide support material. In some embodiments, the amount of the first oxide contained in the catalyst article is from about 1% to about 30% by weight, or from about 5% to about 20% by weight, based on the weight of the first refractory metal oxide support material.

[0030] In some embodiments, the second refractory metal oxide support material comprises alumina, silica, zirconium oxide, titanium dioxide, cerium dioxide, or combinations thereof. In some embodiments, the second refractory metal oxide support material comprises alumina. In some embodiments, the second refractory metal oxide support material comprises zirconium oxide. In some embodiments, based on the total weight of zirconium oxide, the zirconium oxide is doped with about 0.1 wt% to about 40 wt% (e.g., about 1 wt% to about 40 wt%) of lanthanum oxide. In some embodiments, the second refractory metal oxide support material is selected from (e.g., selected from the group consisting of) alumina, silica-doped alumina, titanium dioxide, titanium dioxide-doped alumina, zirconium-doped alumina, zirconium oxide, and zirconium oxide doped with about 0.1 wt% to about 40 wt% (e.g., about 1 wt% to about 40 wt%) of lanthanum oxide based on the weight of zirconium oxide.

[0031] In some embodiments, the PGM component comprises a combination of platinum and palladium. In some embodiments, the weight ratio of palladium to platinum is from about 100 to about 0.01 (e.g., from about 100 to about 0.05). In some embodiments, the weight ratio of palladium to platinum is from about 1 to about 0.01, from about 1 to about 0.05, or from about 0.5 to about 0.1.

[0032] In some implementations, the PGM component is essentially composed of platinum.

[0033] In some implementations, the PGM component is essentially composed of palladium.

[0034] In some implementations, the total PGM component loading on the catalyst is approximately 5 g / ft. 3 Approximately 200g / ft 3 .

[0035] In some embodiments, PGM is loaded onto the second refractory metal oxide support material in an amount of about 0.5% to about 5% by weight, based on the weight of the second refractory metal oxide support material.

[0036] In some embodiments, a first oxide is loaded on a first refractory metal oxide support material, and the amount, based on the weight of the first refractory metal oxide support material, is from about 1 wt% to about 30 wt%, wherein the first refractory metal oxide support material comprises alumina, titanium, or zirconium oxide, wherein the zirconium oxide is doped with lanthanum oxide (e.g., from about 1 wt% to about 40 wt%) based on the weight of the zirconium oxide; the first refractory metal oxide support material further comprises cerium dioxide, and the amount, based on the weight of the first refractory metal oxide support material, is from about 1 wt% to about 50 wt%; the PGM component is loaded on a second refractory metal oxide support material, wherein the second refractory metal oxide support material is selected (e.g., selected from the group consisting of) alumina, silica-doped alumina, titanium dioxide, titanium dioxide-doped alumina, zirconium-doped alumina, zirconium oxide, and zirconium oxide doped with lanthanum oxide (e.g., from about 1 wt% to about 40 wt%) based on the weight of the zirconium oxide.

[0037] In some implementations, the first and second substrate coatings are substantially copper-free.

[0038] In some embodiments, a first substrate coating is disposed directly on the substrate, and a second substrate coating is disposed on at least a portion of the first substrate coating. In some embodiments, the second substrate coating is disposed directly on the substrate, and the first substrate coating is disposed on at least a portion of the second substrate coating. In some embodiments, the catalyst article has a partitioned configuration, wherein the first substrate coating is disposed directly on the substrate for a length of approximately 20% to approximately 100% of the total length from the outlet end; and the second substrate coating is disposed on the substrate for a length of approximately 20% to approximately 100% of the total length from the inlet end. In some embodiments, the catalyst article has a partitioned configuration, wherein the second substrate coating is disposed directly on the substrate for a length of approximately 20% to approximately 100% of the total length from the outlet end; and the first substrate coating is disposed on the substrate for a length of approximately 20% to approximately 100% of the total length from the inlet end.

[0039] On the other hand, an exhaust gas treatment system is provided, which includes a catalyst as disclosed herein, wherein the catalyst is downstream of and in fluid communication with a compression-ignition internal combustion engine.

[0040] In another aspect, a method for treating an exhaust gas stream containing hydrocarbons and / or carbon monoxide and / or NO is provided. x The method includes contacting the waste gas stream with the catalyst or the waste gas treatment system, each as disclosed herein.

[0041] These and other features, aspects, and advantages of this disclosure will become apparent from the following detailed description and the accompanying drawings, which are briefly described below. This disclosure includes any combination of two, three, four, or more of the above embodiments, and any combination of two, three, four, or more features or elements set forth in this disclosure, regardless of whether such features or elements are explicitly combined in the specific embodiments described herein. This disclosure is intended to be understood holistically such that, unless the context clearly indicates otherwise, any separable features or elements of the disclosed subject matter in any aspect and embodiment of this disclosure should be considered composable. Other aspects and advantages of this disclosure will become apparent from the following description. Attached Figure Description

[0042] To provide an understanding of certain embodiments of this disclosure, reference is made to the accompanying drawings, wherein reference numerals indicate components of exemplary embodiments of this disclosure. The drawings are exemplary only and should not be construed as limiting the scope of this disclosure. The disclosure described herein is illustrated in the drawings by way of example, not limitation. For simplicity and clarity, features illustrated in the drawings are not necessarily drawn to scale. For example, the dimensions of some features may be enlarged relative to others for clarity. Furthermore, reference numerals have been repeated in the drawings where deemed appropriate to indicate corresponding or similar elements.

[0043] Figure 1A It may include a perspective view of a honeycomb substrate comprising an oxidation catalyst composition according to the present disclosure.

[0044] Figure 1B It is relative to Figure 1A Magnify and along parallel Figure 1A A partial cross-sectional view of the end face of the substrate, showing an embodiment in which the substrate is a flow-through substrate. Figure 1A An enlarged view of the multiple airflow channels shown.

[0045] Figure 2 This is a cross-sectional view of a representative wall-flow filter.

[0046] Figure 3A , 3B The diagrams for 3C are non-limiting illustrations of possible coating configurations.

[0047] Figure 4 This is a schematic diagram illustrating an embodiment of an exhaust gas treatment system using the DOC catalyst product of this disclosure.

[0048] Figure 5 It is a cartoon description of the components of a test article according to certain embodiments of this disclosure.

[0049] Figure 6This describes the NO2 / NO2 ratio of aged Pt / Pd(2 / 1) powder samples (9% La on Zr (reference); 10% Y on Zr) at 300°C and 250°C. x A graph of yield.

[0050] Figure 7 This describes the NO2 / NO2 ratio of aged Pt / Pd(2 / 1) powder samples (Zr with 9% La (reference); 10% Si / ZrO2) at 300°C and 250°C. x A graph of yield.

[0051] Figure 8 This describes the NO2 / NO2 ratio of aged Pt / Pd(2 / 1) powder samples (Zr with 9% La (reference); Zr75 / Mn24) at 300°C and 250°C. x A graph of yield.

[0052] Figure 9 This describes the NO2 / NO2 ratio of aged Pt / Pd(2 / 1) powder samples (Zr with 9% La (reference); 10% Si / Ti) at 300°C and 250°C. x A graph of yield.

[0053] Figure 10 This describes the NO2 / NO2 ratio of aged Pt / Pd(2 / 1) powder samples (Zr with 9% La (reference); 5% Si / Al) at 300°C and 250°C. x A graph of yield.

[0054] Figure 11 This describes Example 24 of the present invention (1% 2:1 Pt / Pd on ZrO2 and 10% Y) compared to Reference Example 23 (1% 2:1 Pt / Pd on La / ZrO2) in S / de-S (HC 70 CO 50 A graph showing the L / O temperature difference compared to the previous value.

[0055] Figure 12 This is a graph depicting the NO2 difference of Example 24 of the present invention (1% 2:1 Pt / Pd on ZrO2 and 10% Y) compared to Reference Example 23 (La / ZrO2 1% 2:1 Pt / Pd) after S / de-S.

[0056] In some embodiments, the present invention generally provides an oxidation catalyst composition for an exhaust gas treatment system including a compression-ignition internal combustion engine, the composition comprising a platinum group metal (PGM) component including palladium; a first oxide selected from cerium, silicon, iron, cobalt, zinc, chromium, molybdenum, nickel, tungsten, magnesium, antimony, tin, lead, yttrium and combinations thereof; and a first refractory metal oxide support material.

[0057] The subject matter of this disclosure will now be described more fully below. However, the subject matter of this disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art.

[0058] definition

[0059] As used herein, the articles “a” and “an” refer to one or more grammatical objects (e.g., at least one). Any ranges listed herein include end values. The term “about” as used throughout is used to describe and explain small fluctuations. For example, “about” may indicate that the value can be modified by ±5%, ±4%, ±3%, ±2%, ±1%, etc.

[0060] ±0.5%, ±0.4%, ±0.3%, ±0.2%, ±0.1%, or ±0.05%. Whether explicitly stated or not, all numerical values ​​are modified by the term "about". Numerical values ​​modified by the term "about" include specific identifying values. For example, "about 5.0" includes 5.0.

[0061] As used herein, the term “mitigation” means a reduction in quantity caused by any means.

[0062] As used herein, the term "associated" means, for example, "equipped with," "connected to," or "in communication with," such as "electrically connected" or "fluidly connected" or otherwise connected in a manner that performs a function. As used herein, the term "associated" can mean, for example, directly or indirectly associated with, for example, through one or more other articles or elements.

[0063] As used in this article, "average granularity" and D 50 Synonymous, this means that half of the particle size in a particle group is above this point, and the other half is below this point. Particle size refers to the primary particle size. Particle size can be determined using laser scattering techniques, using dispersions or dry powders, for example, according to ASTM method D4464. 90 Particle size distribution indicates that 90% of the particles (by number) have a Feret diameter smaller than that of submicron particles, as measured by scanning electron microscopy (SEM) or transmission electron microscopy (TEM); and that particles containing carriers (micron-sized) have a size measured by a particle size analyzer.

[0064] As used herein, the term "catalyst" refers to a material that facilitates a chemical reaction. A catalyst comprises a "catalytically active substance" and a "support" on which the active substance is carried or loaded.

[0065] As used herein, the term "functional article" means an article comprising a substrate on which a functional coating composition, particularly a catalyst and / or adsorbent coating composition, is disposed.

[0066] As used herein, the term "catalytic article" refers to an article comprising a substrate having a catalyst coating composition.

[0067] As used herein, "CSF" refers to a catalytic fly ash filter, which is a wall-flow filter. A wall-flow filter consists of alternating inlet and outlet channels, with the inlet channel clogging at the outlet end and the outlet channel clogging at the inlet end. The fly ash-laden exhaust gas entering the inlet channel is forced through the filter wall before exiting the outlet channel. In addition to fly ash filtration and regeneration, the CSF can also carry an oxidation catalyst to oxidize CO and HC to CO2 and H2O, or oxidize NO to NO2 to accelerate downstream SCR catalysis or promote the oxidation of fly ash particles at lower temperatures. When positioned downstream of an LNT catalyst, the CSF can also function to suppress the oxidation of H2S emissions during the LNT desulfurization process. In some embodiments, the SCR catalyst can also be directly coated onto a wall-flow filter known as an SCRofF.

[0068] As used herein, "DOC" refers to a diesel oxidation catalyst that converts hydrocarbons and carbon monoxide in the exhaust gas of a diesel engine. In some embodiments, the DOC comprises one or more platinum group metals such as palladium and / or platinum, as well as a refractory metal oxide support material.

[0069] As used in this article, "LNT" refers to lean NO. x The trap contains platinum group metals, cerium dioxide, and is suitable for adsorbing NO under lean-burn conditions. x Catalysts using alkaline earth trapping materials (e.g., BaO or MgO). Under fuel-rich conditions, NO is released. x And then reduce it to nitrogen gas.

[0070] As used herein, the phrase "catalyst system" refers to a combination of two or more catalysts, for example, the oxidation catalyst of the present invention and another catalyst such as lean NO. x A combination of a litter trap (LNT), a catalytic soot filter (CSF), or a selective catalytic reduction (SCR) catalyst. The catalyst system may alternatively be in the form of a substrate coating, wherein the two or more catalysts are mixed together or coated in separate layers.

[0071] The term "configured" as used in the specification and claims is intended to be an open-ended term such as "comprising" or "containing". The term "configured" does not imply the exclusion of other possible articles of manufacture or elements. The term "configured" may be equivalent to "adapted".

[0072] Typically, the term "effective" means, for example, about 35% to 100% by weight or molar, relative to the defined catalytic activity or storage / release activity, such as about 40%, about 45%, about 50%, or about 55% to about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, about 90%, or about 95%.

[0073] As used herein, “substantially free” means “rare or none” or “no intentional addition” and also only in trace and / or unintentional amounts. For example, in some embodiments, “substantially free” means less than 2 wt.%, less than 1.5 wt.%, less than 1.0 wt.%, less than 0.5 wt.%, less than 0.25 wt.%, or less than 0.01 wt.%, based on the indicated total weight of the composition.

[0074] As used herein, the term "exhaust stream" or "exhaust gas stream" refers to any combination of flowing gases that may contain solid or liquid particulate matter. The stream includes gaseous components and, for example, is the exhaust from a lean-burn engine, which may contain certain non-gaseous components such as droplets, solid particles, etc. The exhaust stream from an internal combustion engine typically further includes combustion products (CO2 and H2O), incomplete combustion products (carbon monoxide (CO) and hydrocarbons (HC)), and nitrogen oxides (NOx). x Combustible materials and / or carbonaceous particulate matter (soot), as well as unreacted oxygen and nitrogen. As used herein, the terms “upstream” and “downstream” refer to the relative directions of flow of engine exhaust gas from the engine to the tailpipe, where the engine is located upstream and the tailpipe and any contaminant mitigation products such as filters and catalysts are located downstream of the engine. The inlet end of the substrate is synonymous with the “upstream” end or “front” end. The outlet end is synonymous with the “downstream” end or “rear” end. The upstream zone is upstream of the downstream zone. The upstream zone can be closer to the engine or manifold, while the downstream zone can be further away from the engine or manifold.

[0075] The term "fluidly connected" is used to refer to articles located on the same exhaust line, that is, articles through which a common exhaust gas flows. Fluidly connected articles may be adjacent to each other in the exhaust line. Alternatively, fluidly connected articles may be separated by one or more articles, also referred to as "substrate-coated monolithic materials".

[0076] As used herein, the term "nitrogen oxides" or "NO" refers to...x "Refers to oxides of nitrogen, such as NO or NO2."

[0077] As used in this article, "impregnated" or "impregnated" refers to the catalytic material penetrating into the porous structure of the carrier material.

[0078] As used herein, the term “support” or “support material” refers to any high surface area material, typically a metal oxide material, on which a catalytic noble metal is applied. The term “on a support” means “dispersed on,” “bonded to,” “impregnated in,” “on,” “in,” “deposited on,” or otherwise associated with it.

[0079] As used herein, the term “selective catalytic reduction” (SCR) refers to a catalytic process that uses a nitrogen-containing reducing agent to reduce nitrogen oxides to nitrogen ions (N2).

[0080] As used herein, the term "substrate" refers to the monolithic material on which a catalyst composition (i.e., a catalyst coating) is typically disposed as a substrate coating. In some embodiments, the substrate is a flow-through monolithic filter and a monolithic wall-flow filter. For example, flow-through substrates and wall-flow substrates are taught in International Application Publication WO2016 / 070090, which is incorporated herein by reference. A substrate coating is formed by preparing a slurry containing a specific solids content (e.g., 30-90% by weight) of catalyst in a liquid, then coating the slurry onto the substrate and drying it to provide a layer of substrate coating. The reference to "monolithic substrate" refers to a uniform and continuous monolithic structure from inlet to outlet. A substrate coating is formed by preparing a slurry containing a certain solids content (e.g., 20%-90% by weight) of particles in a liquid medium, then coating the slurry onto the substrate and drying it to provide a layer of substrate coating.

[0081] The terms “on” and “on top of” regarding coatings can be used synonymously. The term “directly on” refers to direct contact. In some embodiments, the disclosed article of manufacture is referred to as being contained “on” a second coating, and such language is intended to cover embodiments with an intermediate layer where direct contact between coatings is not required (i.e., “on” is not equivalent to “directly on”).

[0082] As used herein, the term "vehicle" means, for example, any vehicle having an internal combustion engine, and includes, but is not limited to, passenger cars, sports utility vehicles, minivans, vans, trucks, buses, garbage trucks, freight trucks, engineering vehicles, heavy equipment, military vehicles, agricultural vehicles, etc.

[0083] As used herein, the term "substrate coating" generally means in the art a thin, adhesive coating of catalytic material or other material applied to a substrate material (such as a honeycomb carrier component) that is sufficiently porous to allow the flow of the treated gas stream. The substrate coating may optionally include a binder selected from silica, alumina, titanium dioxide, zirconium oxide, cerium dioxide, or combinations thereof. The binder loading is approximately 0.1 wt.% to 10 wt.% by weight of the substrate coating. As used herein and as described in Heck, Ronald, and Farrauto, Robert, Catalytic Air Pollution Control (New York: Wiley-Interscience, 2002), pp. 18-19, the substrate coating comprises layers of materials of different compositions disposed on the surface of a bulk substrate or on an underlying substrate coating. The substrate may contain one or more substrate coatings, and each substrate coating may differ in some way (e.g., it may differ in its physical properties, such as particle size or microcrystalline phase) and / or in its chemocatalytic function.

[0084] Unless otherwise indicated, all parts and percentages are by weight. Unless otherwise stated, “weight percentage (wt%)” is based on the whole composition excluding any volatiles, i.e., on dry solids content.

[0085] Unless otherwise stated herein or clearly contradicted by the context, all methods described herein may be performed in any suitable order. The use of any and all instances or exemplary language (e.g., “such”) provided herein is intended only to better illustrate the materials and methods and does not limit the scope unless otherwise claimed. The language in this specification should not be construed as indicating that any unclaimed element is necessary for the practice of the materials and methods of this disclosure.

[0086] All U.S. patent applications, published patent applications, and patents cited in this article are incorporated herein by reference.

[0087] Non-restrictive example implementation:

[0088] In a non-limiting manner, some non-limiting embodiments of this disclosure include:

[0089] 1. An oxidation catalyst composition comprising:

[0090] Platinum group metals (PGM) components containing palladium, platinum, or combinations thereof;

[0091] First oxides selected from cerium, silicon, iron, cobalt, zinc, chromium, molybdenum, nickel, tungsten, magnesium, antimony, tin, lead, yttrium, and combinations thereof; and

[0092] First refractory metal oxide carrier material.

[0093] 2. The oxidation catalyst composition according to embodiment 1, wherein the first oxide is selected from oxides of yttrium and silicon.

[0094] 3. The oxidation catalyst composition according to embodiment 1 or 2, based on the weight of the first refractory metal oxide support material, contains a first oxide in an amount of about 1% to about 90% by weight, calculated as oxide.

[0095] 4. The oxidation catalyst composition according to any one of embodiments 1-3, wherein the first oxide is supported on a first refractory metal oxide support material.

[0096] 5. The oxidation catalyst composition according to any one of embodiments 1-4, wherein the first refractory metal oxide support material comprises about 1% by weight to about 99% by weight of zirconium oxide, titanium or aluminum.

[0097] 6. The oxidation catalyst composition according to any one of embodiments 1-4, wherein the first refractory metal oxide support material comprises alumina, silicon dioxide, cerium dioxide, titanium dioxide, silicon dioxide-doped alumina, silicon dioxide-titanium dioxide, silicon dioxide-zirconium oxide, yttrium-zirconium, manganese-zirconium, tungsten-titanium dioxide, zirconium oxide-titanium dioxide, zirconium oxide-cerium dioxide, zirconium oxide-alumina, manganese-alumina, lanthanum-zirconium oxide-alumina, magnesium oxide-alumina, zirconium oxide doped with about 0.1 wt% to about 40 wt% (e.g., about 1 wt% to about 40 wt%) of lanthanum oxide, and combinations thereof.

[0098] 7. The oxidation catalyst composition according to any one of embodiments 1 or 4-6, wherein:

[0099] The first oxide is an oxide of cerium dioxide, and

[0100] Based on the weight of the first refractory metal oxide carrier material, the amount of cerium dioxide present is at most about 99%.

[0101] 8. The oxidation catalyst composition according to any one of embodiments 1 or 4-6, wherein:

[0102] The first oxide is an oxide of yttrium, and

[0103] Based on the weight of the first refractory metal oxide carrier material, the amount of yttrium present is at most about 99%.

[0104] 9. The oxidation catalyst composition according to any one of embodiments 1 or 4-6, wherein:

[0105] The first oxide is an oxide of silicon, and

[0106] Based on the weight of the first refractory metal oxide carrier material, the silicon content is at most about 99%.

[0107] 10. The oxidation catalyst composition according to any one of embodiments 1-9, wherein:

[0108] Palladium is loaded on the first refractory metal oxide support in an amount of about 0% to about 10% by weight, based on the weight of the first refractory metal oxide support.

[0109] Based on the weight of the first refractory metal oxide support, platinum is loaded onto the first refractory metal oxide support in an amount from about 0% to about 10% by weight; and

[0110] Based on the weight of the first refractory metal oxide support material, at least one of platinum or palladium is present in an amount of about 0.1% by weight or greater.

[0111] 11. The oxidation catalyst composition according to any one of embodiments 1-10, wherein the PGM component comprises a combination of platinum and palladium.

[0112] 12. The oxidation catalyst composition according to embodiment 11, wherein the weight ratio of palladium to platinum is about 100 to about 0.01.

[0113] 13. The oxidation catalyst composition according to embodiment 11, wherein the weight ratio of palladium to platinum is from about 1 to about 0.01.

[0114] 14. The oxidation catalyst composition according to any one of embodiments 1-13 further comprises a second refractory metal oxide support material.

[0115] 15. The oxidation catalyst composition according to embodiment 14, wherein the second refractory metal oxide support material comprises alumina, silicon dioxide, zirconium oxide, titanium dioxide, cerium dioxide, silicon dioxide-doped alumina, silicon dioxide-titanium dioxide, silicon dioxide-zirconium oxide, yttrium-zirconium, manganese-zirconium, tungsten-titanium dioxide, zirconium oxide-titanium dioxide, zirconium oxide-cerium dioxide, zirconium oxide-alumina, manganese-alumina, lanthanum-zirconium oxide, lanthanum-zirconium oxide-alumina, magnesium-alumina, or combinations thereof.

[0116] 16. The oxidation catalyst composition according to embodiment 14 or 15, wherein the second refractory metal oxide support material comprises base metal oxides and combinations thereof selected from oxides of cerium, iron, cobalt, zinc, chromium, molybdenum, nickel, tungsten, copper, magnesium, antimony, tin, lead, and yttrium.

[0117] 17. The oxidation catalyst composition according to embodiment 14, wherein the PGM component is loaded on the second refractory metal oxide support material in an amount of about 0.1% to about 10% by weight, based on the weight of the second refractory metal oxide support material.

[0118] 18. The oxidation catalyst composition according to embodiment 14, wherein the second refractory metal oxide support material comprises alumina or zirconium oxide.

[0119] 19. The oxidation catalyst composition according to embodiment 18, wherein, based on the weight of zirconium oxide, the zirconium oxide in the second refractory metal oxide support material is doped with lanthanum in an amount of about 0.1% to about 40% by weight, based on the oxide content.

[0120] 20. The oxidation catalyst composition according to any one of embodiments 14-19, wherein the first oxide is supported on a first refractory metal oxide support material, and the PGM component is supported on a second refractory metal oxide support material.

[0121] 21. The oxidation catalyst composition according to embodiment 20, wherein the PGM component is loaded on the second refractory metal oxide support material in an amount of about 0.1% to about 10% by weight, based on the weight of the second refractory metal oxide support material.

[0122] 22. The oxidation catalyst composition according to embodiment 14, wherein:

[0123] Based on the weight of the first refractory metal oxide support material, the amount of the first oxide loaded on the first refractory metal oxide support material is from about 1% to about 40% by weight, calculated as oxide; and

[0124] The PGM component is loaded on a second refractory metal oxide support material, wherein the second refractory metal oxide support material is selected from alumina, silica-doped alumina, titanium dioxide, titanium dioxide-doped alumina, zirconium-doped alumina, zirconium oxide, and zirconium oxide doped with about 0.1 wt% to about 40 wt% (e.g., about 1 wt% to about 40 wt%) of lanthanum oxide based on zirconium oxide.

[0125] 23. The oxidation catalyst composition according to embodiment 22, wherein the first oxide is selected from oxides of yttrium and silicon.

[0126] 24. The oxidation catalyst composition according to embodiment 22, wherein the first refractory metal oxide support material comprises cerium dioxide, the amount of which is from about 1% by weight to about 50% by weight based on the weight of the first refractory metal oxide support material.

[0127] 25. The oxidation catalyst composition according to any one of embodiments 1-24, wherein the oxidation catalyst composition is substantially free of copper.

[0128] 26. A catalytic article comprising an inlet end and an outlet end having a defined total length, and a catalytic coating disposed on at least a portion thereof, the catalytic coating comprising a first substrate coating and a second substrate coating, wherein:

[0129] The first substrate coating comprises a first oxide and a first refractory metal oxide carrier material, wherein the first oxide is selected from oxides of cerium, silicon, iron, cobalt, zinc, chromium, molybdenum, nickel, tungsten, magnesium, antimony, tin, lead, yttrium, and combinations thereof; and the first oxide is loaded on the first refractory metal oxide carrier material; and

[0130] The second substrate coating comprises a platinum group metal (PGM) component including palladium, platinum, or a combination thereof, and a second refractory metal oxide carrier material, wherein the PGM component is loaded on the second refractory metal oxide carrier material.

[0131] 27. The catalytic article according to embodiment 26, based on the weight of the first refractory metal oxide support material, contains a first oxide in an amount of about 1% to about 40% by weight, calculated as oxide.

[0132] 28. The catalyst article according to embodiment 26, wherein the first oxide is an oxide of yttrium, and the amount of yttrium present is at most about 99% based on the weight of the first refractory metal oxide support material.

[0133] 29. The catalyst article according to embodiment 26, wherein the first oxide is an oxide of silicon, and the silicon content is at most about 99% based on the weight of the first refractory metal oxide support material.

[0134] 30. The catalyst article according to any one of embodiments 26-29, wherein the first refractory metal oxide support material comprises about 1% by weight to about 99% by weight of zirconium oxide, titanium or aluminum.

[0135] 31. The catalytic article according to any one of embodiments 26-29, wherein the first refractory metal oxide support material comprises alumina.

[0136] 32. The catalyst article according to any one of embodiments 26-29, wherein, based on the total weight of zirconium oxide, the first refractory metal oxide support material comprises zirconium oxide doped with about 0.1 wt% to about 40 wt% (e.g., about 1 wt% to about 40 wt%) of lanthanum oxide.

[0137] 33. The catalyst article according to any one of embodiments 26-32, wherein the second refractory metal oxide support material comprises alumina, silicon dioxide, zirconium oxide, titanium dioxide, cerium dioxide, or a combination thereof.

[0138] 34. The catalyst article according to any one of embodiments 26-32, wherein the second refractory metal oxide support material includes manganese.

[0139] 35. The catalyst article according to any one of embodiments 26-32, wherein the second refractory metal oxide support material comprises alumina or zirconium oxide.

[0140] 36. The catalyst article according to embodiment 35, wherein, based on the total weight of zirconium oxide, the zirconium oxide in the second refractory metal oxide support material is doped with about 0.1% to about 40% lanthanum oxide.

[0141] 37. The catalyst article according to any one of embodiments 26-32, wherein the second refractory metal oxide support material is selected from alumina, silica-doped alumina, titanium dioxide, titanium dioxide-doped alumina, zirconium-doped alumina, zirconium oxide, and zirconium oxide doped with about 1% to about 40% by weight of lanthanum oxide based on zirconium oxide.

[0142] 38. The catalyst article according to any one of embodiments 26-37, wherein the PGM component comprises a combination of platinum and palladium.

[0143] 39. The catalyst article according to embodiment 38, wherein the weight ratio of palladium to platinum is about 100 to about 0.01.

[0144] 40. The catalyst article according to embodiment 38, wherein the weight ratio of palladium to platinum is from about 1 to about 0.01.

[0145] 41. The catalyst article according to any one of embodiments 26-40, wherein the total PGM component loading on the catalyst article is about 5 g / ft 3 Approximately 200g / ft 3 .

[0146] 42. In the catalytic article according to any one of embodiments 26-41, PGM is loaded on the second refractory metal oxide support material in an amount of about 0.5% to about 10% by weight (e.g., about 0.5% to about 5% by weight) based on the weight of the second refractory metal oxide support material.

[0147] 43. The catalyst article according to embodiment 26, wherein:

[0148] Based on the weight of the first refractory metal oxide support material, the amount of the first oxide loaded on the first refractory metal oxide support material is from about 1% to about 30% by weight, in terms of oxide, wherein the first refractory metal oxide support material includes alumina, titanium or zirconium oxide, wherein based on the weight of zirconium oxide, zirconium oxide is doped with about 0.1% to about 40% lanthanum oxide.

[0149] The first refractory metal oxide support material optionally further comprises cerium dioxide, the amount of which is from about 1% to about 50% by weight, based on the weight of the first refractory metal oxide support material; and

[0150] The PGM component is loaded on a second refractory metal oxide support material, wherein the second refractory metal oxide support material is selected from alumina, silica-doped alumina, titanium dioxide, titanium dioxide-doped alumina, zirconium-doped alumina, zirconium oxide, and zirconium oxide doped with lanthanum oxide at a weight ratio of about 0.1 wt% to about 40 wt% based on zirconium oxide.

[0151] 44. The catalyst article according to any one of embodiments 26-43, wherein the first and second substrate coatings are substantially free of copper.

[0152] 45. The catalyst article according to any one of embodiments 26-44, wherein the first substrate coating is disposed directly on the substrate, and the second substrate coating is disposed on at least a portion of the first substrate coating.

[0153] 46. ​​The catalyst article according to any one of embodiments 26-44, wherein the second substrate coating is disposed directly on the substrate, and the first substrate coating is disposed on at least a portion of the second substrate coating.

[0154] 47. The catalyst article according to any one of embodiments 26-44, wherein the catalyst article has a partitioned configuration, wherein a first substrate coating is disposed directly on a substrate for a length of about 20% to about 100% of the total length from the outlet end; and a second substrate coating is disposed on a substrate for a length of about 20% to about 100% of the total length from the inlet end.

[0155] 48. The catalyst article according to any one of embodiments 26-44, wherein the catalyst article has a partitioned configuration, wherein a second substrate coating is directly disposed on a substrate for a length of about 20% to about 100% of the total length from the outlet end; and a first substrate coating is disposed on a substrate for a length of about 20% to about 100% of the total length from the inlet end.

[0156] 49. A catalyst article comprising an inlet end and an outlet end having a defined total length, and a catalytic coating disposed on at least a portion thereof, said catalytic coating comprising a first substrate coating, a second substrate coating, and a third substrate coating, wherein:

[0157] The first substrate coating comprises a first oxide and a first refractory metal oxide carrier material, wherein the first oxide is selected from oxides of yttrium and silicon, and the first oxide is loaded on the first refractory metal oxide carrier material;

[0158] The second substrate coating comprises a base metal oxide component including cerium dioxide, zirconium oxide, lanthanum oxide, copper oxide, or a combination thereof, and a second refractory metal oxide carrier material, wherein the base metal oxide component is loaded on the second refractory metal oxide carrier material; and

[0159] The third substrate coating comprises a platinum group metal (PGM) component including palladium, platinum, or a combination thereof, and a third refractory metal oxide carrier material, wherein the PGM component is loaded on the third refractory metal oxide carrier material.

[0160] 50. The catalyst article according to embodiment 49, wherein the first refractory metal oxide support material comprises about 1% by weight to about 99% by weight of zirconium oxide, titanium or aluminum.

[0161] 51. The catalyst article according to embodiment 49 or 50, wherein the second refractory metal oxide support material comprises alumina, silicon dioxide, zirconium oxide, titanium dioxide, cerium dioxide, silicon dioxide-doped alumina, titanium dioxide, titanium dioxide-doped alumina, zirconium-doped alumina, zirconium oxide, silicon dioxide-titanium dioxide, silicon dioxide-zirconium oxide, yttrium-zirconium, manganese-zirconium, tungsten-titanium dioxide, zirconium oxide-titanium dioxide, zirconium oxide-cerium dioxide, zirconium oxide-alumina, manganese-alumina, lanthanum-zirconium oxide, lanthanum-zirconium oxide-alumina, magnesium oxide-alumina, or combinations thereof.

[0162] 52. The catalyst article according to embodiment 49 or 50, wherein the second refractory metal oxide support material comprises alumina.

[0163] 53. The catalyst article according to embodiment 49 or 50, wherein the second refractory metal oxide support material comprises silicon dioxide-doped alumina.

[0164] 54. The catalyst article according to embodiment 49 or 50, wherein the second refractory metal oxide support material comprises zirconium oxide.

[0165] 55. The catalyst article according to embodiment 54, wherein, based on the total weight of zirconium oxide, the zirconium oxide in the second refractory metal oxide support material is doped with about 0.1% by weight to about 40% by weight of lanthanum oxide.

[0166] 56. The catalyst article according to any one of embodiments 49-55, wherein the third refractory metal oxide support material comprises alumina, silicon dioxide, zirconium oxide, titanium dioxide, cerium dioxide, silicon dioxide-doped alumina, titanium dioxide, titanium dioxide-doped alumina, zirconium-doped alumina, zirconium oxide, silicon dioxide-titanium dioxide, silicon dioxide-zirconia, tungsten-titanium dioxide, zirconium oxide-titanium dioxide, zirconium oxide-cerium dioxide, zirconium oxide-alumina, lanthanum-zirconia, lanthanum-zirconia-alumina, magnesium oxide-alumina, or combinations thereof.

[0167] 57. The catalytic article according to any one of embodiments 49-56, wherein the PGM component comprises a combination of platinum and palladium.

[0168] 58. The catalyst article according to any one of embodiments 49-57, wherein the first substrate coating is disposed directly on the substrate, and the second substrate coating is disposed on at least a portion of the first substrate coating.

[0169] 59. The catalyst article according to any one of embodiments 49-57, wherein the second substrate coating is disposed directly on the substrate, and the first substrate coating is disposed on at least a portion of the second substrate coating.

[0170] 60. The catalyst article according to any one of embodiments 49-57, wherein a first substrate coating is disposed directly on the substrate, a second substrate coating is disposed on at least a portion of the first substrate coating, and a third substrate coating is disposed on at least a portion of the second substrate coating.

[0171] 61. The catalyst article according to any one of embodiments 49-57, wherein the third substrate coating is disposed directly on the substrate, the second substrate coating is disposed on at least a portion of the third substrate coating, and the first substrate coating is disposed on at least a portion of the second substrate coating.

[0172] 62. The catalyst article according to any one of embodiments 49-57, wherein the first substrate coating is disposed directly on the substrate, the third substrate coating is disposed on at least a portion of the first substrate coating, and the second substrate coating is disposed on at least a portion of the third substrate coating.

[0173] 63. The catalyst article according to any one of embodiments 49-57, wherein the second substrate coating is disposed directly on the substrate, the third substrate coating is disposed on at least a portion of the second substrate coating, and the first substrate coating is disposed on at least a portion of the third substrate coating.

[0174] 64. The catalyst article according to any one of embodiments 49-57, wherein the second substrate coating is disposed directly on the substrate, the first substrate coating is disposed on at least a portion of the second substrate coating, and the third substrate coating is disposed on at least a portion of the first substrate coating.

[0175] 65. The catalyst article according to any one of embodiments 49-57, wherein the catalyst article has a partitioned configuration, wherein:

[0176] The first substrate coating is directly disposed on the substrate from the outlet end to a length of approximately 20% to approximately 100% of the total length;

[0177] The second substrate coating is disposed on the substrate from the inlet end to a length of approximately 20% to approximately 100% of the total length; and

[0178] The third substrate coating is disposed on the substrate from the inlet end to a length of approximately 20% to approximately 100% of the total length.

[0179] 66. An exhaust gas treatment system comprising a catalytic article according to any one of embodiments 26-65, wherein the catalytic article is downstream of and in fluid communication with a compression-ignition internal combustion engine.

[0180] 67. A device for treating hydrocarbons and / or carbon monoxide and / or NO x A method for treating an exhaust gas stream, the method comprising contacting the exhaust gas stream with a catalyst article as described in any one of embodiments 26-65 or an exhaust gas treatment system as described in embodiment 66.

[0181] Oxidation catalyst composition

[0182] As described above, this disclosure generally provides an oxidation catalyst composition comprising a refractory metal oxide support material, a platinum group metal (PGM) component, and a first oxide selected from cerium, silicon, iron, cobalt, zinc, chromium, molybdenum, nickel, tungsten, magnesium, antimony, tin, lead, yttrium, and combinations thereof. Each of the various components of the composition is further described below.

[0183] Refractory metal oxide carrier

[0184] The oxidation catalyst compositions disclosed herein comprise refractory metal oxide support materials. As used herein, "refractory metal oxide" refers to porous metal oxide materials that exhibit chemical and physical stability at high temperatures, such as those associated with diesel engine exhaust gases. Exemplary refractory metal oxides include, but are not limited to, alumina, silica, zirconium oxide, titanium dioxide, cerium dioxide, and physical mixtures or chemical combinations thereof, including atomically doped combinations and including high surface area or active compounds, such as activated alumina. In some embodiments, the refractory metal oxide support includes alumina, silica, cerium dioxide, titanium dioxide, silica-doped alumina, silica-titanium dioxide, silica-zirconium oxide, yttrium-zirconium, manganese-zirconium, tungsten-titanium dioxide, zirconium oxide-titanium dioxide, zirconium oxide-cerium oxide, zirconium oxide-alumina, manganese-alumina, lanthanum-zirconium oxide, lanthanum-zirconium oxide-alumina, magnesium-alumina, and combinations thereof. Exemplary alumina includes macroporous boehmite, γ-alumina, and δ / θ alumina. Useful commercially available alumina includes active alumina, such as high-bulk-density gamma-alumina, low- or medium-bulk-density macroporous gamma-alumina, and low-bulk-density macroporous boehmite and gamma-alumina.

[0185] High-surface-area refractory oxide supports, such as alumina support materials, also known as "γ-alumina" or "active alumina," typically exhibit surface areas exceeding 60 μm. 2 / g, typically up to about 200m 2 / g or higher BET surface area. Such activated alumina is typically a mixture of the γ and δ phases of alumina, but may also contain significant amounts of η, κ, and θ alumina phases. As used herein, "BET surface area" generally refers to the Brunauer, Emmett, Teller method for determining surface area by N2 adsorption. In some embodiments, the refractory metal oxide support material (e.g., activated alumina) has a specific surface area of ​​60 m² / g or higher. 2 / g to 350m 2 / g, for example, about 90m 2 / g to approximately 250m 2 / g.

[0186] In some embodiments, the refractory metal oxide support material includes alumina (Al₂O₃), silicon dioxide (SiO₂), zirconium oxide (ZrO₂), titanium dioxide (TiO₂), cerium dioxide (CeO₂), or physical mixtures or chemical combinations thereof. In some embodiments, the refractory metal oxide support that can be used in the oxidation catalyst compositions disclosed herein is doped with another metal oxide, including but not limited to silicon dioxide (SiO₂), cerium dioxide (CeO₂), titanium dioxide (TiO₂), or lanthanum oxide (La₂O₃). In some embodiments, the refractory metal oxide support is selected from materials doped such as Si-doped alumina (including but not limited to 1-10% SiO₂-Al₂O₃), Si-doped titanium dioxide (including but not limited to 1-10% SiO₂-TiO₂), or Si-doped zirconium oxide (including but not limited to 5-30% SiO₂-ZrO₂). In some embodiments, the refractory metal oxide support material includes SiO2-doped Al2O3, SiO2-doped TiO2, or SiO2-doped ZrO2 (including but not limited to 5-30% SiO2-ZrO2).

[0187] In some embodiments, the refractory metal oxide support material comprises zirconium oxide. In some embodiments, the zirconium oxide is doped with one or more dopants. In some embodiments, the refractory metal oxide support material comprises about 5% to about 99% of zirconium oxide (i.e., the total amount of dopants present is about 1% to about 95%). In some embodiments, the refractory metal oxide support material comprises about 20% to about 99% of zirconium oxide (i.e., the total amount of dopants present is about 1% to about 80%). In some embodiments, the zirconium oxide is doped with lanthanum oxide. In some embodiments, the refractory metal oxide support material comprises about 0.1% to about 40% (e.g., about 1% to about 40%) of La₂O₃. In some embodiments, based on the weight of the zirconium oxide, the zirconium oxide is doped with about 1%, about 2%, about 3%, about 4%, about 5%, about 6%, about 7%, about 8%, about 9%, or about 10% to about 15%, about 20%, about 25%, about 30%, about 35%, or about 40% of lanthanum oxide by weight. In some embodiments, zirconium oxide is doped with about 1% to about 10% lanthanum oxide. In some embodiments, zirconium oxide is doped with about 9% lanthanum oxide.

[0188] Dopant metal oxides can be introduced using techniques such as initial wet impregnation. In some embodiments, the metal oxides may exist in the doped refractory metal oxide support material as a mixed oxide, meaning that the metal oxides are covalently bonded to each other through shared oxygen atoms.

[0189] The oxidation catalyst composition may include any and any amount of the refractory metal oxides described above. For example, the refractory metal oxides in the catalyst composition may include from about 15 wt%, about 20 wt%, about 25 wt%, about 30 wt%, about 35 wt%, about 40%, about 45%, or about 50 wt% to about 55 wt%, about 60 wt%, about 65 wt%, about 70 wt%, about 75 wt%, about 80 wt%, about 85 wt%, about 90 wt%, about 95 wt%, or about 99 wt% based on the total dry weight of the catalyst composition.

[0190] This document refers to a "first" refractory metal oxide support material and, in some embodiments, a "second" refractory metal oxide support material, to distinguish each type of refractory metal oxide support material. The first and second refractory metal oxide support materials may be the same or different. In some embodiments, the first and second refractory metal oxide support materials are the same. In other embodiments, the first and second refractory metal oxide support materials are different.

[0191] In some embodiments, the first refractory metal oxide support material comprises zirconium oxide. In some embodiments, the first refractory metal oxide support comprises zirconium oxide doped with lanthanum oxide. In some embodiments, the first refractory metal oxide support material comprises zirconium oxide doped with 1-40% lanthanum oxide. In some embodiments, the first refractory metal oxide support material comprises zirconium oxide doped with 1-10% lanthanum oxide. In some embodiments, the first refractory metal oxide support material comprises zirconium oxide doped with about 9% lanthanum oxide.

[0192] In some embodiments, the first refractory metal oxide support material is substantially free of lanthanum.

[0193] In some implementations, the second refractory metal oxide carrier material comprises manganese.

[0194] In some embodiments, the second refractory metal oxide support material includes alumina, silicon dioxide, zirconium oxide, titanium dioxide, cerium dioxide, silicon dioxide-doped alumina, silicon dioxide-titanium dioxide, silicon dioxide-zirconium oxide, yttrium-zirconium, manganese-zirconium, tungsten-titanium dioxide, zirconium oxide-titanium dioxide, zirconium oxide-cerium dioxide, zirconium oxide-alumina, manganese-alumina, lanthanum-zirconium oxide, lanthanum-zirconium oxide-alumina, magnesium-alumina, or combinations thereof. In some embodiments, the second refractory metal oxide support material comprises alumina, silicon dioxide, zirconium oxide, titanium dioxide, cerium dioxide, or combinations thereof. In one or more embodiments, the second refractory metal oxide support is selected from (e.g., selected from the group consisting of): γ-alumina, silicon dioxide-doped alumina, cerium dioxide-doped alumina, and titanium dioxide-doped alumina. In some embodiments, the second refractory metal oxide support material is selected from (e.g., from the group consisting of) alumina, silica-doped alumina, titanium dioxide, titanium dioxide-doped alumina, zirconium-doped alumina, zirconium oxide, and zirconium oxide doped with about 0.1 wt% to about 40 wt% (e.g., about 1 wt% to about 40 wt%) of lanthanum oxide based on zirconium oxide. In some embodiments, the second refractory metal oxide support material is selected from (e.g., from the group consisting of): γ-alumina and alumina doped with about 1 wt% to about 10 wt% SiO2. In some embodiments, the second refractory metal oxide support material is alumina doped with about 1 wt% to about 10 wt% SiO2, for example, about 1 wt%, about 2 wt%, about 3 wt%, about 4 wt%, about 5 wt%, about 6 wt%, about 7 wt%, about 8 wt%, about 9 wt%, or about 10 wt% SiO2. In some embodiments, the second refractory metal oxide support material is alumina.

[0195] In some embodiments, the second refractory metal oxide support material comprises zirconium oxide. In some embodiments, the second refractory metal oxide support material is selected from (e.g., selected from the group consisting of) alumina, silica-doped alumina, zirconium oxide, and zirconium oxide doped with about 0.1 wt% to about 40 wt% (e.g., about 1 wt% to about 40 wt%) of lanthanum oxide based on zirconium oxide. In some embodiments, the second refractory metal oxide support is zirconium oxide doped with lanthanum oxide. In some embodiments, the second refractory metal oxide support material is zirconium oxide doped with 1-40% lanthanum oxide. In some embodiments, the second refractory metal oxide support material is zirconium oxide doped with 1-10% lanthanum oxide. In some embodiments, the second refractory metal oxide support material is zirconium oxide doped with about 9% lanthanum oxide. In some embodiments, both the first and second refractory metal oxide support materials comprise zirconium oxide doped with about 1-10% lanthanum oxide. In some embodiments, the first refractory metal oxide support material comprises zirconium oxide doped with about 1-10% lanthanum oxide, and the second refractory metal oxide support material is alumina.

[0196] In some implementations, the second refractory metal oxide support material is essentially lanthanum-free.

[0197] Platinum group metals (PGM) composition

[0198] The oxidation catalyst compositions described herein comprise a platinum group metal (PGM) component. PGMs include platinum (Pt), palladium (Pd), ruthenium (Ru), rhodium (Rh), osmium (Os), iridium (Ir), gold (Au), and mixtures thereof. The PGM component may comprise PGMs in any valence state. As used herein, the term “PGM component” refers both to the catalytically active form of the individual PGM and the corresponding PGM compound, complex, etc., which decomposes or otherwise transforms into its catalytically active form upon calcination or use with the catalyst, typically a metal or metal oxide. PGMs may be in metallic form with a zero valence (“PGM(0)”), or PGMs may be in oxide form (e.g., including but not limited to platinum or oxides thereof). The amount of PGM(0) may be determined using ultrafiltration followed by inductively coupled plasma / optical emission spectrometry (ICP-OES) or by X-ray photoelectron spectroscopy (XPS).

[0199] In some embodiments, the PGM component includes platinum, palladium, or a combination thereof. In some embodiments, the PGM component is palladium. In some embodiments, the PGM component is platinum. In some embodiments, the PGM component is a combination of palladium and platinum. Exemplary weight ratios of such Pd / Pt combinations include, but are not limited to, a Pd:Pt weight ratio of about 100 to about 0.01, such as about 100:1, about 50:1, about 40:1, 30:1, about 25:1, about 20:1, about 15:1, about 10:1, about 5:1, about 4:1, about 3:1, about 2:1, about 1:1, about 1:2, about 1:5, about 1:10, or about 1:20 Pd / Pt. In some embodiments, the Pd / Pt weight ratio is about 100. In some embodiments, the palladium to platinum weight ratio is about 1 to about 0.01, about 1 to about 0.05, or about 0.5 to about 0.1. In each case, the weight ratio is based on the element (metal).

[0200] The PGM component is loaded (e.g., impregnated) on a refractory metal oxide support material as described above. Based on the total weight of the refractory metal oxide support material including the loaded PGM, the PGM component may be present in an amount from about 0.01 wt% to about 20 wt% (e.g., from about 0.1 wt% to about 10 wt%; from about 0.5 wt% to about 5 wt%). Based on the total weight of the refractory metal oxide support material including the loaded PGM, the oxidation catalyst composition may contain the PGM, such as Pd or Pt / Pd, in amounts from about 0.1 wt%, about 0.5 wt%, about 1.0 wt%, about 1.5 wt%, or about 2.0 wt% to about 3 wt%, about 5 wt%, about 7 wt%, about 9 wt%, about 10 wt%, about 12 wt%, about 15 wt%, about 16 wt%, about 17 wt%, about 18 wt%, about 19 wt%, or about 20 wt%.

[0201] In some embodiments, the platinum group metal component is loaded onto the second refractory metal oxide support material. In some embodiments, the PGM component is platinum, palladium, or a combination thereof, and the PGM is loaded onto the second refractory metal oxide support material in an amount of about 0.5 to about 5% by weight, based on the weight of the second refractory metal oxide support material. In some embodiments, the PGM is loaded onto the second refractory metal oxide support material in an amount of about 2% by weight, based on the weight of the second refractory metal oxide support material.

[0202] In some implementations, the total PGM component loading on the catalyst is approximately 5 g / ft. 3 Approximately 200g / ft 3 .

[0203] First oxide

[0204] In some embodiments, the oxidation catalyst compositions disclosed herein further comprise a first oxide, which may be a base metal oxide or a metal-like oxide. As used herein, a "base metal oxide" refers to an oxide compound comprising a transition metal or a lanthanide metal that is catalytically active for the oxidation of one or more waste gas components. As used herein, a "metal-like oxide" refers to an oxide compound comprising a metal-like substance (e.g., silicon) that is catalytically active for the oxidation of one or more waste gas components. For ease of reference herein, the concentration of the first oxide material is reported according to the elemental metal concentration rather than the oxide form. Generally, at least a portion of the first oxide is disposed on or within a refractory metal oxide support. Depending on the valence of the specific metal, these oxides may comprise various oxidation states of the metal, such as monooxides, dioxides, trioxides, tetroxides, etc.

[0205] Suitable base metals include, but are not limited to, cerium, iron, cobalt, zinc, chromium, nickel, tungsten, copper, molybdenum, or combinations thereof. In some embodiments, the base metal is selected from (e.g., from the group consisting of) cerium, copper, iron, cobalt, zinc, chromium, nickel, tungsten, molybdenum, and combinations thereof. In some embodiments, the base metal is selected from (e.g., from the group consisting of) cerium, iron, cobalt, zinc, chromium, molybdenum, nickel, tungsten, molybdenum, and combinations thereof. In some embodiments, the base metal is selected from (e.g., from the group consisting of) cerium, copper, and combinations thereof. In some embodiments, the base metal is selected from cerium, iron, cobalt, zinc, chromium, molybdenum, nickel, tungsten, magnesium, antimony, tin, lead, yttrium, manganese, and combinations thereof.

[0206] In some embodiments, the oxidation catalyst composition is substantially free of copper. "Substantially free of" copper means that no copper has been intentionally added and may be present only in trace amounts as an impurity, such as less than 0.1 wt%, less than 0.01 wt%, less than 0.001 wt%, or even 0 wt%.

[0207] The concentration of any single first oxide can vary, but is typically from about 1% to about 50% by weight relative to the weight of the refractory metal oxide support material on which it is supported (e.g., from about 1% to about 50% by weight, from about 1% to about 30% by weight, or from about 5% to about 20% by weight relative to the weight of the refractory metal oxide support material). In some embodiments, the concentration of any single first oxide is from about 1%, about 2%, about 3%, about 4%, about 5%, about 6%, about 7%, about 8%, about 9%, or about 10% by weight to about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, or about 50% by weight, based on the weight of the refractory metal oxide support material.

[0208] In some embodiments, the first oxide is loaded on a first refractory metal oxide support material. In some embodiments, the first oxide is cerium dioxide. In some embodiments, the amount of cerium dioxide present is at most about 50% based on the weight of the first refractory metal oxide support material. In some embodiments, cerium dioxide is present in amounts of about 1% to about 10%, about 5% to about 20%, about 10% to about 30%, or about 20% to about 50% by weight, based on the weight of the first refractory metal oxide support material.

[0209] Preparation of oxidation catalyst composition

[0210] In some embodiments, the disclosed oxidation catalyst compositions can be prepared by a wet impregnation method. Wet impregnation, also known as capillary impregnation or dry impregnation, is commonly used to synthesize heterogeneous materials, i.e., catalysts. Typically, a metal precursor (e.g., PGM or base metal / metal-like oxide precursor) is dissolved in an aqueous or organic solution, and then the metal-containing solution is added to a refractory metal oxide support having a pore volume equal to the volume of the added solution. Capillary action draws the solution into the pores of the support. Adding a solution exceeding the pore volume of the support causes the transport of the solution to shift from a capillary process to a much slower diffusion process. The catalyst can then be dried and calcined to remove volatile components from the solution, thereby depositing the metal onto the surface of the catalyst support. The maximum loading is limited by the solubility of the precursor in the solution. The concentration distribution of the impregnated material depends on the mass transfer conditions within the pores during impregnation and drying. Those skilled in the art will recognize other methods for loading various components (e.g., PGM or base metal / metal-like oxide) into the supports of the compositions of the present invention, such as adsorption, precipitation, etc.

[0211] During a subsequent calcination step, or at least during the initial stage of using the composition, the metal precursor compound is converted into a catalytically active form of the metal or its compound. Non-limiting examples of suitable PGM precursors include palladium nitrate, tetraamine palladium nitrate, tetraamine platinum acetate, and platinum nitrate. Non-limiting examples of suitable base metal oxide precursors are nitrates, acetates, or other soluble salts, such as salts of cerium, copper, etc. A suitable method for preparing the oxidation catalyst composition is to prepare a mixture of the desired PGM compound (e.g., platinum and / or palladium compounds) and a solution of at least one support, such as a finely divided high-surface-area refractory metal oxide support, such as lanthanum oxide-doped alumina, said support being sufficiently dry to absorb substantially all of the solution to form a wet solid that subsequently combines with water to form a coatable slurry. In some embodiments, the slurry is acidic, for example, with a pH of about 2 to less than about 7. The pH of the slurry can be lowered by adding an appropriate amount of inorganic or organic acid to the slurry. A combination of both can be used when compatibility with the acidic material and the raw material is taken into account. Examples of inorganic acids include, but are not limited to, nitric acid. Examples of organic acids include, but are not limited to, acetic acid, propionic acid, oxalic acid, malonic acid, succinic acid, glutamic acid, adipic acid, maleic acid, fumaric acid, phthalic acid, tartaric acid, citric acid, etc. The impregnated refractory metal oxide carrier material is then dried and calcined as described above.

[0212] The wet impregnation method described above can be similarly used to introduce the first oxide component into a refractory metal oxide carrier material. Impregnation can be carried out stepwise (sequentially) or in various combinations.

[0213] Catalysts

[0214] On one hand, an oxidation catalyst article comprising an oxidation catalyst composition as disclosed herein is provided. The article includes a substrate on which at least a portion is disposed the oxidation catalyst composition as disclosed herein. Suitable substrates are described below.

[0215] Substrate

[0216] In some embodiments, the oxidation catalyst composition of the present invention is disposed on a substrate to form a catalytic article. Catalytic articles comprising a substrate are typically used as part of an exhaust gas treatment system (e.g., catalyst articles comprising, but not limited to, articles comprising the oxidation catalyst composition disclosed herein). A useful substrate is three-dimensional, having a length, diameter, and volume similar to a cylinder. The shape need not conform to a cylinder. The length is the axial length defined by the inlet end and the outlet end.

[0217] In some embodiments, the substrate for the disclosed composition may be made of any material commonly used in the preparation of automotive catalysts and will typically include a metallic or ceramic honeycomb structure. The substrate typically provides multiple wall surfaces on which a carrier coating composition is applied and adhered, thereby serving as the substrate for the catalyst composition.

[0218] The ceramic substrate can be made of any suitable refractory material, such as cordierite, cordierite-α-alumina, aluminum titanate, silicon titanate, silicon carbide, silicon nitride, zircon mullite, spodumene, alumina-silica-magnesium oxide, zirconium silicate, sillimanite, magnesium silicate, zircon, selenite, α-alumina, aluminosilicate, etc.

[0219] The substrate may also be metallic, including one or more metals or metal alloys. Metallic substrates may comprise any metallic substrate, such as those with openings or "perforations" in the channel walls. Metallic substrates can be used in various shapes, for example, granules, corrugated sheets, or monolithic foams. Specific examples of metallic substrates include, but are not limited to, heat-resistant base metal alloys, especially those in which iron is a basic or major component. Such alloys may contain one or more of nickel, chromium, and aluminum, and the total amount of these metals may advantageously comprise at least about 15 wt.% (by weight) of the alloy, for example, about 10 to about 25 wt.% of chromium, about 1 to about 8 wt.% of aluminum, and 0 to about 20 wt.% of nickel, in each case based on the weight of the substrate. Examples of metallic substrates include, but are not limited to, substrates having straight channels; substrates having blades projecting along the axial channels to interrupt airflow and open communication between channels; and conduits with blades and perforations to enhance gas transport between channels, allowing radial gas transport in the bulk. In particular, the metal substrate may be advantageously used in a closely coupled position in some embodiments, thereby allowing rapid heating of the substrate and correspondingly rapid heating of the catalyst composition (e.g., an oxidation catalyst composition) coated therein.

[0220] Any suitable substrate for the catalytic articles disclosed herein can be used, such as a monolithic substrate having fine, parallel airflow channels extending through the substrate from an inlet or outlet face, such that the channels are open to fluid flowing through the substrate (“flow-through substrate”). Another suitable substrate is of the type having a plurality of fine, substantially parallel airflow channels extending along the longitudinal axis of the substrate, wherein typically each channel is blocked at one end of the substrate body, with alternating channels blocked at opposite end faces (“wall-flow filter”). Flow-through and wall-flow substrates are also taught, for example, in International Application Publication No. WO2016 / 070090, which is incorporated herein by reference in its entirety.

[0221] In some embodiments, the catalyst substrate includes a honeycomb substrate in the form of a wall-flow filter or a flow-through substrate. In some embodiments, the substrate is a wall-flow filter. Flow-through substrates and wall-flow filters will be discussed further below.

[0222] Flow-through substrate

[0223] In some embodiments, the substrate is a flow-through substrate (e.g., a monolithic substrate, including a flow-through honeycomb monolithic substrate). The flow-through substrate has narrow, parallel airflow channels extending from an inlet end to an outlet end of the substrate, such that the channels are open to fluid flow. The channels, following a substantially straight path from their fluid inlet to their fluid outlet, are defined by walls on which a catalytic coating is disposed, so that the gas flowing through the channels contacts the catalytic material. The flow channels of the flow-through substrate are thin-walled channels that can have any suitable cross-sectional shape and size, such as trapezoidal, rectangular, square, sinusoidal, hexagonal, elliptical, circular, etc. As described above, the flow-through substrate can be ceramic or metallic.

[0224] The volume of the flow-through substrate can be, for example, about 50 inches. 3 Approximately 1200 inches 3 The cell density (inlet opening) is about 60 cells per square inch (cpsi) to about 500 cpsi or up to about 900 cpsi, for example about 200 to about 400 cpsi, and the wall thickness is about 50 to about 200 micrometers or about 400 micrometers. Figure 1A and 1B An exemplary substrate 2 is shown in the form of a flowable substrate coated with a catalyst composition as described herein. Reference Figure 1A The exemplary substrate 2 has a cylindrical shape and a cylindrical outer surface 4, an upstream end face 6, and a corresponding downstream end face 8 identical to the end face 6. The substrate 2 has a plurality of parallel fine gas flow channels 10 formed therein. Figure 1B As shown, the flow channel 10 is formed by the wall 12 and extends from the upstream end face 6 through the carrier 2 to the downstream end face 8. The channel 10 is unobstructed, thereby allowing fluid (e.g., airflow) to flow longitudinally through the carrier 2 via its airflow channel 10. As in Figure 1B As can be more readily seen, the wall 12 is sized and configured such that the airflow channel 10 has a generally regular polygonal shape. As shown, the catalyst composition can be applied in multiple different layers if desired. In the illustrated embodiment, the catalyst composition consists of both a discrete underlayer 14 adhered to the wall 12 of the carrier member and a second discrete top layer 16 coated on the underlayer 14. This disclosure can be practiced with one or more (e.g., two, three, or four or more) catalyst composition layers and is not limited to this. Figure 1BThe two-layer embodiment shown herein. Further coating configurations are disclosed below.

[0225] Wall-flow filter substrate

[0226] In some implementations, the substrate is a wall-flow filter, which typically has multiple thin, substantially parallel airflow channels extending along the longitudinal axis of the substrate. Typically, each channel is blocked at one end of the substrate body, with alternating channels blocked at opposite end faces. Such monolithic wall-flow filter substrates can contain up to about 900 or more airflow channels (or “cells”) per square inch of cross-section, but much fewer can be used. For example, the substrate can have about 7 to 600 cells per square inch, more typically about 100 to 400 cells per square inch (“cpsi”). Cells can have rectangular, square, circular, elliptical, triangular, hexagonal, or other polygonal cross-sections.

[0227] Figure 2 The image shows a cross-sectional view of a substrate section of a monolithic wall-flow filter, illustrating alternating blocked and open channels (cells). Blocked or shut-off ends 100 alternate with open channels 101, each opposite end being open and blocked respectively. The filter has an inlet end 102 and an outlet end 103. Arrows passing through porous cell walls 104 indicate exhaust gas flow entering the open cell end, diffusing through the porous cell walls 104, and exiting the open outlet cell end. The shut-off end 100 prevents gas flow and promotes diffusion through the cell walls. Each cell wall will have an inlet side 104a and an outlet side 104b. The channels are surrounded by cell walls.

[0228] The substrate of wall-flow filter products can have, for example, about 50 cm. 3 Approximately 100cm 3 Approximately 200cm 3 Approximately 300cm 3 Approximately 400cm 3 Approximately 500cm 3 Approximately 600cm 3 Approximately 700cm 3 Approximately 800cm 3 Approximately 900cm 3 or about 1000cm 3 Approximately 1500cm 3 Approximately 2000cm 3 Approximately 2500cm 3 Approximately 3000cm 3 Approximately 3500cm 3 Approximately 4000cm 3 Approximately 4500cm 3 or about 5000cm 3The volume. Wall flow filter substrates typically have a wall thickness of about 50 micrometers to about 2000 micrometers, for example, about 50 micrometers to about 450 micrometers or about 150 micrometers to about 400 micrometers.

[0229] The walls of a wall-flow filter are porous and typically have a wall porosity of at least about 50% or at least about 60% prior to the application of a functional coating, wherein the average pore size is at least about 5 micrometers. For example, in some embodiments, the wall-flow filter article substrate will have a porosity of ≥50%, ≥60%, ≥65%, or ≥70%. For example, prior to the application of a catalytic coating, the wall-flow filter article substrate will have a wall porosity of about 50%, about 60%, about 65%, or about 70% to about 75%, about 80%, or about 85%, and an average pore size of about 5 micrometers, about 10 micrometers, about 20 micrometers, about 30 micrometers, about 40 micrometers, or about 50 micrometers to about 60 micrometers, about 70 micrometers, about 80 micrometers, about 90 micrometers, or about 100 micrometers.

[0230] As used herein, the terms "wall porosity" and "substrate porosity" mean the same thing and are used interchangeably. Porosity is the ratio of pore volume to the total volume of the substrate. Pore size can be determined according to the ISO 15901-2 (static volume) procedure for nitrogen pore size analysis. Nitrogen pore size can be determined on a Micromeritics TRISTAR 3000 series instrument. Nitrogen pore size can be determined using Barrett-Joyner-Halenda (BJH) calculations and 33 desorption points. In some embodiments, useful wall-flow filters have high porosity, thus allowing high loadings of the catalyst composition during operation without generating excessive back pressure.

[0231] Coating composition and formulation

[0232] To produce the catalytic articles of this disclosure, a substrate as described herein is contacted with an oxidation catalyst composition as disclosed herein to provide a coating (i.e., a slurry comprising particles of the catalyst composition is disposed on the substrate). The coating of the oxidation catalyst composition on the substrate is referred herein to, for example, as a “catalytic coating composition” or “catalytic coating.” As used herein, the terms “catalytic composition” and “catalytic coating composition” are synonymous.

[0233] The oxidation catalyst compositions disclosed herein can be prepared using binders, such as ZrO2 binders derived from suitable precursors like zirconium oxyacetate or any other suitable zirconium precursor like zirconium oxynitrate. Zirconium acetate binders provide a uniform and intact coating after thermal aging, such as when the catalyst is exposed to temperatures of at least about 600°C, for example about 800°C, and to an environment with about 5% or more of water vapor. Other potentially suitable binders include, but are not limited to, alumina and silica. Alumina binders include alumina, aluminum hydroxide, and alumina hydroxyaluminate. Colloidal forms of aluminum salts and alumina can also be used. Silica binders include various forms of SiO2, including silicates and colloidal silica. Binder compositions can include any combination of zirconium oxide, alumina, and silica. Other exemplary binders include, but are not limited to, boehmite, γ-alumina, or δ / θ alumina, and silica sol. When present, the binder is typically used in an amount of about 1-5 wt% of the total substrate coating load. Alternatively, the binder can be zirconium oxide-based or silica-based, such as zirconium acetate, zirconium oxide sol, or silica sol. When present, alumina binders are typically used at approximately 0.05 g / in. 3 Approximately 1g / in 3 The amount used. In some implementations, the binder is aluminum oxide.

[0234] The catalytic coating of the present invention may include one or more coatings, wherein at least one layer comprises the oxidation catalyst composition of the present invention. The catalytic coating of the present invention may include a single layer or multiple coatings. The catalytic coating may include one or more thin adhesive coatings disposed on and adhered to at least a portion of a substrate. The entire coating comprises a single “coating”.

[0235] In some embodiments, the catalytic article of the present invention may include the use of one or more catalyst layers and combinations thereof. The catalytic material may be present only on the inlet side of the substrate wall, only on the outlet side, on both the inlet and outlet sides, or the wall itself may be wholly or partially composed of the catalytic material. The catalytic coating may be on the surface of the substrate wall and / or in the pores of the substrate wall, i.e., in the substrate wall and / or on the substrate wall. Therefore, the phrase "catalytic coating disposed on a substrate" means on any surface, such as on the wall surface and / or on the pore surface.

[0236] This catalyst composition can typically be applied as a coating containing a support material on which the catalytically active substance is disposed. A support coating is formed by preparing a slurry containing a specified solid content (e.g., about 10% to about 60% by weight) of support in a liquid medium, then applying the slurry onto a substrate and drying and calcining it to provide a coating. If multiple coatings are applied, the substrate is dried and calcined after each layer is applied and / or after applying a large number of desired layers. In one or more embodiments, the catalytic material is applied as a substrate coating onto the substrate. A binder can also be used as described above.

[0237] For the purpose of coating catalyst substrates such as honeycomb substrates, the above-described catalyst compositions are typically mixed independently with water to form a slurry. In addition to catalyst particles, the slurry may optionally contain binders (e.g., alumina, silica), water-soluble or water-dispersible stabilizers, accelerators, associative thickeners, and / or surfactants (including anionic, cationic, nonionic, or amphoteric surfactants). The typical pH range of the slurry is from about 3 to about 6. Acidic or basic species may be added to the slurry to adjust the pH accordingly. For example, in some embodiments, the pH of the slurry is adjusted by adding an aqueous solution of ammonium hydroxide or nitric acid.

[0238] The slurry can be ground to enhance particle mixing and the formation of homogeneous materials. Grinding can be performed in a ball mill, continuous mill, or other similar equipment, and the solids content of the slurry can be, for example, about 20-60 wt%, more specifically about 20-40 wt%. In one embodiment, the ground slurry is characterized by D 90 The particle size is from about 10 micrometers to about 40 micrometers, for example, from 10 micrometers to about 30 micrometers, for example, from about 10 micrometers to about 15 micrometers.

[0239] The slurry is then coated onto the catalyst substrate using any substrate coating technique known in the art. In some embodiments, the catalyst substrate is dipped into the slurry once or multiple times, or otherwise coated with the slurry. The coated substrate is then dried at an elevated temperature (e.g., 100-150°C) for a period of time (e.g., 10 minutes to 3 hours), and then calcined, for example, by heating at 400-600°C, typically for about 10 minutes to about 3 hours. After drying and calcination, the final substrate coating can be considered substantially solvent-free.

[0240] After calcination, the catalyst loading obtained by the above-described substrate coating technique can be determined by calculating the difference in weight between the coated and uncoated substrates. As will be apparent to those skilled in the art, the catalyst loading can be modified by altering the slurry rheology. Furthermore, the coating / drying / calcination process for producing the substrate coating can be repeated as needed to construct the coating to the desired loading level or thickness, meaning that more than one substrate coating may be applied.

[0241] In some embodiments, the catalyst article comprises a catalytic coating disposed on at least a portion of a substrate, the catalytic coating comprising a first substrate coating and a second substrate coating. In some embodiments, the first substrate coating comprises a first oxide and a first refractory metal oxide support material, each as described herein. In some embodiments, the first oxide is supported on the first refractory metal oxide support material.

[0242] In some embodiments, the second carrier coating comprises a platinum group metal (PGM) component including palladium and a second refractory metal oxide carrier material, each as described herein. In some embodiments, the PGM component is loaded onto the second refractory metal oxide carrier material.

[0243] A substrate coating can be applied such that different coatings can be in direct contact with the substrate. Alternatively, one or more "below coatings" may be present such that at least a portion of the catalyst or adsorbent coating or multiple coatings is not in direct contact with the substrate (but is in contact with the below coating). One or more "above coatings" may also be present such that at least a portion of the coating or multiple coatings is not directly exposed to the gas stream or atmosphere (but is in contact with the above coating). The catalyst composition of the present invention may be in a substrate layer above the substrate.

[0244] Alternatively, the catalyst composition of the present invention can be in a top coating layer above a base coating layer. The catalyst composition can be present in both a top layer and a bottom layer. Either layer can extend the entire axial length of the substrate; for example, the bottom layer can extend the entire axial length of the substrate, and the top layer can extend the entire axial length of the substrate over the bottom layer. Each of the top and bottom layers can extend from either an inlet end or an outlet end.

[0245] For example, both the base coat and the top coat can extend from the same end of the substrate, wherein the top coat partially or completely covers the base coat, and wherein the base coat extends part or all of the length of the substrate, and wherein the top coat extends part or all of the length of the substrate. Alternatively, the top coat can cover a portion of the base coat. For example, the base coat can extend the entire length of the substrate, and the top coat can extend from the inlet or outlet end by about 10%, about 20%, about 30%, about 40%, about 50%, about 60%, about 70%, about 80%, or about 90% of the substrate length.

[0246] Optionally, the bottom layer may extend from the inlet or outlet end to approximately 10%, 15%, 25%, 30%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, or 95% of the substrate length, and the top layer may extend from the inlet or outlet end to approximately 10%, 15%, 25%, 30%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, or 95% of the substrate length, wherein at least a portion of the top layer covers the bottom layer. This "covered" area may, for example, extend from approximately 5% to approximately 80% of the substrate length, such as approximately 5%, 10%, 20%, 30%, 40%, 50%, 60%, or 70% of the substrate length.

[0247] The top and / or bottom coatings may be in direct contact with the substrate. Alternatively, one or more "bottom coatings" may be present such that at least a portion of the top and / or bottom coatings is not in direct contact with the substrate (but rather in contact with the bottom coating). One or more "top coatings" may also be present such that at least a portion of the top and / or bottom coatings is not directly exposed to a gas stream or atmosphere (but rather in contact with the top coating). The bottom coating is a layer "below" the coating, the top coating is a layer "above" the coating, and the intermediate layer is a layer "between" the two coatings.

[0248] The top and bottom coatings can be in direct contact with each other without any intermediate layer. Alternatively, the different coatings may not be in direct contact, with a "gap" between the two zones. An intermediate layer (if present) prevents direct contact between the top and bottom layers. An intermediate layer can partially prevent direct contact between the top and bottom layers, thereby allowing partial direct contact between the top and bottom layers. The intermediate layer, the bottom coating, and the top coating may contain one or more catalysts or may not contain a catalyst. The catalytic coating of the present invention may comprise more than one identical layer, for example, more than one layer comprising the same catalyst composition.

[0249] The catalytic coating can advantageously be “partitioned,” comprising partitioned catalytic layers, i.e., wherein the catalytic coating contains a varying composition across its axial length over the substrate. This can also be described as “lateral partitioning.” For example, layers may extend from the inlet end to the outlet end, extending approximately 10%, approximately 20%, approximately 30%, approximately 40%, approximately 50%, approximately 60%, approximately 70%, approximately 80%, or approximately 90% of the substrate length. Another layer may extend from the outlet end to the inlet end, extending approximately 10%, approximately 20%, approximately 30%, approximately 40%, approximately 50%, approximately 60%, approximately 70%, approximately 80%, or approximately 90% of the substrate length. Different coatings may be adjacent to each other and not overlap. Alternatively, different layers may partially overlap each other, thereby providing a third “intermediate” zone. The intermediate zone may extend from approximately 5% to approximately 80% of the substrate length, for example, approximately 5%, approximately 10%, approximately 20%, approximately 30%, approximately 40%, approximately 50%, approximately 60%, or approximately 70% of the substrate length.

[0250] Different layers may each extend the entire length of the substrate, or each may each extend a portion of the substrate's length, and may partially or completely cover or pad each other. Each different layer may extend from either an inlet end or an outlet end. Different catalytic compositions may be present in each individual coating. The catalytic coating of the present invention may comprise more than one identical layer.

[0251] The regions disclosed herein are defined by the relationship between the coatings. For different coatings, there are many possible partitioning configurations. For example, there may be upstream and downstream regions, upstream, intermediate, and downstream regions, or four distinct regions, etc. When two layers are adjacent and do not overlap, there are upstream and downstream regions. When two layers overlap to some extent, there are upstream, downstream, and intermediate regions. For example, when the coating extends the entire length of the substrate and different coatings extend a certain length from the exit end and cover a portion of the first coating, upstream and downstream regions exist.

[0252] In some embodiments, the first and second coatings may overlap, with the first coating on top of the second or vice versa (i.e., top / bottom), for example, where the first coating extends from the inlet end to the outlet end and the second coating extends from the outlet end to the inlet end. In this case, the catalytic coating will include an upstream region, an intermediate (cover) region, and a downstream region. The first and / or second coatings may be synonymous with the aforementioned top and / or bottom layers.

[0253] In some implementations, the first coating may extend from the inlet end to the outlet end and the second coating may extend from the outlet end to the inlet end, wherein the layers do not overlap each other, for example, they may be adjacent to each other.

[0254] Figure 3A , 3BFigures 3C and 3C illustrate some possible coating configurations with two coatings, wherein at least one of the coatings comprises a catalyst composition as disclosed herein. A substrate wall 200 is shown with coatings 201 (top coating) and 202 (bottom coating) disposed thereon. This is a simplified illustration; in the case of a porous wall flow substrate, the pores and the coatings adhered to the pore walls are not shown, and the blocked ends are not shown. Figure 3A In the middle, coatings 201 and 202 each extend the entire length of the substrate, with the top layer 201 covering the bottom layer 202. Figure 3A The substrate does not have a partitioned coating configuration. Figure 3B In the middle, the base coating 202 extends approximately 50% of the substrate length from the outlet, and the top coating 201 extends more than 50% of the length from the inlet, and covers a portion of the cover layer 202, providing an upstream region 203, an intermediate cover region 205, and a downstream region 204. Figure 3C In the process, coating 202 extends from the outlet for about 50% of the length of the substrate, and coating 201 extends from the inlet for more than 50% of the length and is part of the cover layer 202, thereby providing an upstream region 203, an intermediate cover region 205 and a downstream region 204. Figure 3A , 3B 3C can be used in coating compositions on illustrated wall-flow or flow-through substrates.

[0255] In some implementations, the first and second substrate coatings are substantially copper-free.

[0256] In some embodiments, a first substrate coating is disposed directly on the substrate, and a second coating is disposed on at least a portion of the first coating. In some embodiments, a second substrate coating is disposed directly on the substrate, and a first substrate coating is disposed on at least a portion of the second substrate coating.

[0257] In some embodiments, the catalyst article has a partitioned configuration, wherein a first substrate coating is directly disposed on a substrate extending from the outlet end to approximately 20% to approximately 100% of the total length; and a second substrate coating is disposed on a substrate extending from the inlet end to approximately 20% to approximately 100% of the total length. In some embodiments, the catalyst article has a partitioned configuration, wherein a second substrate coating is directly disposed on a substrate extending from the outlet end to approximately 20% to approximately 100% of the total length; and a first substrate coating is disposed on a substrate extending from the inlet end to approximately 20% to approximately 100% of the total length.

[0258] The loading (concentration) of this (oxidative) catalytic coating, and any region, layer, or segment of the coating, on the substrate is, for example, about 0.3 g / in based on the volume of the substrate. 3 Approximately 6.0 g / in 3 or approximately 0.4 g / in 3Approximately 0.5g / in 3 Approximately 0.6g / in 3 Approximately 0.7g / in 3 Approximately 0.8g / in 3 Approximately 0.9g / in 3 Or approximately 1.0 g / in 3 Approximately 1.5 g / in 3 Approximately 2.0g / in 3 Approximately 2.5g / in 3 Approximately 3.0g / in 3 Approximately 3.5g / in 3 Approximately 4.0g / in 3 Approximately 4.5g / in 3 Approximately 5.0g / in 3 or approximately 5.5g / in 3 This refers to the dry solids weight per volume of the substrate, such as the dry solids weight per volume of honeycomb monomers. Concentration is measured per cross-section of the substrate or per entire substrate. In some embodiments, the top coating is present at a lower loading than the bottom coating.

[0259] Based on the volume of the substrate, the loading of the PGM component (e.g., palladium and optionally platinum) of the disclosed oxidation catalyst composition on the substrate can be in the range of approximately 2 g / ft. 3 Approximately 5g / ft 3 or about 10g / ft 3 Approximately 250g / ft 3 For example, from about 20g / ft 3 Approximately 30g / ft 3 Approximately 40g / ft 3 Approximately 50g / ft 3 or about 60g / ft 3 Approximately 100g / ft 3 Approximately 150g / ft 3 or about 200g / ft 3 Approximately 210g / ft 3 Approximately 220g / ft 3 Approximately 230g / ft 3 Approximately 240g / ft 3 or approximately 250g / ft 3 Based on the weight of the layer, PGM is present in the catalyst layer, for example, in amounts of about 0.1 wt%, about 0.5 wt%, about 1.0 wt%, about 1.5 wt%, or about 2.0 wt%, to about 3 wt%, about 5 wt%, about 7 wt%, about 9 wt%, about 10 wt%, about 12 wt%, or about 15 wt%.

[0260] Catalyst activity

[0261] In some embodiments, the hydrocarbon (e.g., methane) or CO present in the exhaust gas stream is reduced compared to the level of hydrocarbons or CO present in the exhaust gas stream prior to contact with the catalyst product. In some embodiments, the efficiency of the reduction in HC and / or CO levels is measured as conversion efficiency. In some embodiments, conversion efficiency is expressed as the ignition temperature (i.e., T). 50 or T 70 It is measured using a function of ). T 50 or T 70 Ignition temperature is the temperature at which a catalyst composition can convert 50% or 70% of hydrocarbons or carbon monoxide into carbon dioxide and water, respectively. Generally, for any given catalyst composition, the lower the measured ignition temperature, the more efficient the catalyst composition is in catalytic reactions such as hydrocarbon conversion.

[0262] In some implementation schemes, sulfur poisoning was not observed.

[0263] In some implementations, the NO2 level in the exhaust gas is increased compared to the level of nitrogen dioxide (NO2) present in the exhaust gas before contact with the catalyst product. This increase in NO2 content generally promotes the catalytic activity of downstream SCR catalysts.

[0264] Exhaust gas treatment system

[0265] On the other hand, a method for treating hydrocarbons (HC), carbon monoxide (CO), and nitrogen oxides (NOx) from internal combustion engines is provided. x The system comprises a diesel oxidation catalyst (DOC) product as described herein, located downstream of an internal combustion engine. The engine may be, for example, a diesel engine operating under combustion conditions where air exceeds the air required for stoichiometric combustion, i.e., lean-burn conditions. In other embodiments, the engine may be a gasoline engine (e.g., a lean-burn gasoline engine) or an engine associated with a stationary source (e.g., a generator or pumping station).

[0266] Exhaust gas treatment systems typically contain more than one catalyst, located downstream of the engine and in fluid communication with the exhaust gas flow. The system may include, for example, oxidation catalysts (e.g., DOC), selective catalytic reduction catalysts (SCR), and one or more other components, including a reducing agent injector, a soot filter, an ammonia oxidation catalyst (AMOx), or lean NOx. xA reducing agent (LNT). Articles containing a reducing agent syringe are reducing articles. Reduction systems include reducing agent syringes and / or pumps and / or reservoirs, etc. The processing system of the present invention may further include a soot filter and / or an ammonia oxidation catalyst. The soot filter may be uncatalyzed or may be catalyzed (CSF), such as the CSF disclosed herein. For example, from upstream to downstream, the processing system of the present invention may include articles containing DOC, CSF, urea syringes, SCR articles, and articles containing AMOx. Lean NO may also be included. x LNT (Low-Nutrient Toxin)

[0267] The relative positions of the various catalytic components within the exhaust gas treatment system can vary. In the exhaust gas treatment system and method of the present invention, the exhaust gas stream is contained into one or more articles or treatment systems by entering at an upstream end and exiting at a downstream end. The inlet end of the substrate or article is synonymous with the "upstream" end or "front" end. The outlet end is synonymous with the "downstream" end or "rear" end. The treatment system is typically located downstream of the internal combustion engine and is in fluid communication with the internal combustion engine.

[0268] exist Figure 4 An exemplary exhaust treatment system is illustrated, depicting a schematic diagram of exhaust treatment system 20. As shown, the exhaust treatment system may include multiple catalyst assemblies connected in series downstream of engine 22 (e.g., a lean-burn engine). At least one catalyst assembly will include an oxidation catalyst composition (e.g., DOC, CSF, or both) as described herein. The oxidation catalyst composition of this disclosure may be combined with a number of other catalyst materials and may be placed in different locations compared to other catalyst materials. Figure 4 Five catalyst components 24, 26, 28, 30, and 32 are shown in series; however, the total number of catalyst components can vary, and five components are just one example.

[0269] Non-limiting, Table 1 shows various exhaust gas treatment system configurations of one or more embodiments of this disclosure. Note that each catalyst is connected to the next catalyst via an exhaust gas conduit, such that the engine is upstream of catalyst A, catalyst A is upstream of catalyst B, catalyst B is upstream of catalyst C, catalyst C is upstream of catalyst D, and catalyst D is upstream of catalyst E (if present). References to component AE in the table may be related to... Figure 5 Cross-referencing of the same name in the same file.

[0270] The DOC catalysts listed in Table 1 can be any catalyst commonly used as an oxidation catalyst in diesel engines to efficiently convert CO and HC into CO2 and H2O.

[0271] The ccDOC catalysts mentioned in Table 1 can be any catalyst commonly used as diesel engine oxidation catalysts, located in a closely coupled position toward the engine block to convert CO and HC into CO2 and H2O and generate heat through exothermic reaction to effectively heat downstream catalysts.

[0272] The DOC (BMO) catalysts specified in Table 1 can be any catalyst conventionally used as an oxidation catalyst in diesel engines to convert CO and HC into CO2 and H2O and do not include platinum group metals (PGMs). BMO is indicated as a base metal oxide as defined herein. A combination of component A (DOC) + component B (DOC (BMO)) is indicated as an arrangement in the same tank or in two separate tanks where component A is located upstream of component B.

[0273] The DOC+BMO catalyst mentioned in Table 1 is a diesel engine oxidation catalyst containing PGM and BMO components on the same substrate.

[0274] The LNT catalysts listed in Table 1 can be those traditionally used for NO production. x Any catalyst that acts as a trap, and typically contains NO. x The adsorbent composition comprises base metal oxides (BaO, MgO, CeO2, etc.) and platinum group metals (e.g., Pt and Rh) for catalyzing the oxidation and reduction of NO.

[0275] The LT-NA catalysts mentioned in Table 1 can be any catalyst capable of adsorbing NO at low temperatures (<250℃). x (For example, NO or NO2) and a catalyst that releases it into the gas stream at high temperatures (>250°C). The released NO x Typically, N2 and H2O are converted via downstream SCR or SCRoF catalysts. LT-NA catalysts typically comprise Pd-promoted zeolites or Pd-promoted refractory metal oxides.

[0276] The reference to SCR in the table refers to the SCR catalyst. The reference to SCRof (or SCR on a filter) refers to a particulate or dust filter (e.g., a wall-flow filter) that may contain an SCR catalyst composition.

[0277] The reference to AMOx in the table refers to an ammonia oxidation catalyst, which may be provided downstream of the catalyst in one or more embodiments of this disclosure to remove any slipping ammonia from an exhaust gas treatment system. In some embodiments, the AMOx catalyst may contain a PGM component. In some embodiments, the AMOx catalyst may include a base coat and a top coat, the base coat having a PGM and the top coat having SCR functionality.

[0278] As those skilled in the art will recognize, in the configurations listed in Table 1, any one or more of components A, B, C, D, or E can be mounted on a particulate filter (such as a wall-flow filter) or a flow-through honeycomb substrate. In some embodiments, the engine exhaust system includes one or more catalyst compositions mounted near the engine (in an immediately coupled location, CC) and additional catalyst compositions mounted under the vehicle body (in an underfloor location, UF). In some embodiments, the exhaust treatment system may further include a urea injection assembly.

[0279] Table 1. Possible exhaust gas treatment system configurations

[0280]

[0281]

[0282] Methods for treating waste gas flow

[0283] The present disclosure relates to a method for treating engine exhaust gas containing hydrocarbons and / or carbon monoxide and / or NO. x The method includes contacting the exhaust gas stream with the catalyst of this disclosure or the exhaust treatment system of this disclosure.

[0284] Typically, hydrocarbons (HC) and carbon monoxide (CO) present in the exhaust gas of any engine can be converted into carbon dioxide and water. Hydrocarbons typically present in engine exhaust gas include C1-C6 hydrocarbons (i.e., lower hydrocarbons) such as methane, but higher hydrocarbons (greater than C6) can also be detected. In some embodiments, the method includes contacting the gas stream with the catalyst or exhaust gas treatment system of this disclosure at a temperature sufficient to reduce the CO and / or HC levels in the gas stream for a time sufficient to reduce the CO and / or HC levels in the gas stream.

[0285] Typically, any NO, such as NO, present in engine exhaust gas... x The species can be converted (oxidized) into NO2. In some embodiments, the method includes contacting the gas stream with the catalyst or exhaust gas treatment system of this disclosure at a temperature sufficient to oxidize at least a portion of the NO present in the gas stream to NO2 for a time sufficient to oxidize at least a portion of the NO present in the gas stream to NO2.

[0286] The articles, systems, and methods of the present invention are suitable for treating exhaust gas streams from mobile emission sources (e.g., trucks and automobiles). The articles, systems, and methods of the present invention are also suitable for treating exhaust gas streams from stationary sources (e.g., power plants).

[0287] It will be apparent to those skilled in the art that suitable modifications and alterations can be made to the compositions, methods, and applications described herein without departing from the scope of any embodiment or aspect thereof. The compositions and methods provided are exemplary and are not intended to limit the scope of the claimed embodiments. All the various embodiments, aspects, and options disclosed herein can be combined in all variations. The scope of the compositions, formulations, methods, and processes described herein includes all actual or potential combinations of the embodiments, aspects, options, examples, and preferences described herein. All patents and publications referenced herein are incorporated herein by reference for their specific teachings as mentioned, unless otherwise specifically stated by inclusion. Example

[0288] This disclosure is illustrated more fully by way of the following examples, which are set forth for the purpose of illustrating the subject matter and should not be construed as limiting it. Unless otherwise indicated, all parts and percentages are by weight, and all weight percentages are expressed on a dry weight basis, meaning excluding water content, unless otherwise indicated.

[0289] Example 1A: Pd on a lanthanum-containing zirconium oxide support

[0290] Samples containing lanthanum-containing zirconium oxide with 2% palladium were prepared. A measured amount of palladium nitrate solution was impregnated onto a La-containing zirconium oxide support (containing approximately 9 wt% lanthanum oxide) to obtain a coated powder with 2 wt% Pd based on the total weight of the impregnated support. The Pd-impregnated support powder was added to deionized water (the slurry's solid content was 30 wt%). The slurry was milled using a ball mill to D... 90 Particle size less than 15 μm. The ground slurry was dried at 120 °C with stirring and calcined in air at 590 °C for 2 hours. The calcined sample was cooled in air until it reached room temperature. The calcined powder was pulverized and sieved to a particle size range of 250-500 μm. The sieved powder was divided into two fractions. The first fraction was evaluated as a fresh sample. The second fraction was aged in air containing 10% vapor at 800 °C for 16 hours to provide an aged sample.

[0291] Example 1B: Pt and Pd on an alumina support

[0292] Platinum and palladium samples (2% of the total PGM weight) were prepared on an alumina support. Platinum nitrate and palladium nitrate (Pt and Pd weight ratio of 2:1) were impregnated onto high-surface-area alumina (surface area approximately 150 m²) according to standard procedures. 2 / g). Add the alumina carrier powder impregnated with 2% PGM to deionized water (the solid content of the slurry is 30% by weight). Grind the slurry to D using a ball mill. 90Particle size less than 15 μm. The ground slurry was dried at 120 °C with stirring and calcined in air at 590 °C for 2 hours. The calcined sample was cooled in air until it reached room temperature. The calcined powder was pulverized and sieved to a particle size range of 250-500 μm. The sieved powder was divided into two fractions. The first fraction was evaluated as a fresh sample. The second fraction was aged in air containing 10% vapor at 800 °C for 16 hours to provide an aged sample.

[0293] Example 2: Ce / Mn-doped alumina support

[0294] Base metal oxide materials were prepared by impregnating an alumina support with cerium nitrate and then drying it. The cerium-impregnated alumina support was then impregnated with manganese nitrate, dried, calcined, crushed, and sieved as in Examples 1A and 1B to provide Ce / Mn-doped alumina support material (particle size in the range of 250-500 μm), comprising, by weight, 10% cerium dioxide and 10% manganese oxide on the alumina based on the total weight of the doped alumina support material. The sieved powder was divided into two fractions. The first fraction was evaluated as a fresh sample. The second fraction was aged at 800°C for 16 hours in air containing 10% vapor to provide an aged sample.

[0295] Example 3: Mn-doped lanthanum-containing zirconium oxide support

[0296] Using the procedure of Example 2, but replacing alumina with La-zirconium oxide and removing cerium nitrate, a base metal oxide material (containing about 9 wt% lanthanum oxide) was prepared by impregnating a La-zirconium oxide-containing support with manganese nitrate. After calcination, the resulting powder had a Mn content of about 10 wt% – calculated as an oxide and based on the total weight of the impregnated support.

[0297] Example 4: Ce / Mn-doped lanthanum-containing zirconium oxide support

[0298] Using the procedure of Example 3, base metal oxide materials (containing about 9 wt% lanthanum oxide) were prepared by sequentially impregnating cerium nitrate and manganese nitrate onto a La-containing zirconium oxide support. After calcination, the resulting powder had a content of about 10 wt% Ce and 10 wt% Mn—calculated as oxides and based on the total weight of the impregnated support.

[0299] Example 5: Cu / Mn-doped lanthanum-containing zirconium oxide support

[0300] Using the procedure of Example 4, but instead of cerium nitrate, copper nitrate was used to prepare a base metal oxide material (containing about 9 wt% lanthanum oxide) by sequentially impregnating copper nitrate and manganese nitrate onto a La-containing zirconium oxide support. After calcination, the resulting powder had a content of about 10 wt% Cu and 10 wt% Mn—calculated as oxides and based on the total weight of the impregnated support.

[0301] Example 6: Ce / Cu / Mn-doped lanthanum-containing zirconium oxide support

[0302] The procedure of Example 5 was used, but first impregnated with cerium nitrate. Base metal oxide materials (containing about 9 wt% lanthanum oxide) were prepared by sequentially impregnating a La-containing zirconium oxide support with cerium nitrate, copper nitrate, and manganese nitrate. After calcination, the resulting powder had a content of about 10 wt% Ce, 10 wt% Cu, and 10 wt% Mn—calculated as oxides and based on the total weight of the impregnated support.

[0303] Examples 7-12. Pd catalyst products

[0304] The catalyst products were prepared from the powders of Examples 1A and 2-6. To prepare the products, appropriate powder samples (fresh and aged) were loaded into separate test beds. The total volume of the test bed was 1 ml, with two equal sections: a bottom and a top, as shown. Figure 5 As shown. In each case, the top was filled with 2% Pd on the La / Zr support powder of Example 1A, and the bottom of the test bed was filled with a reference lanthanum-containing zirconium oxide support (Example 7), or a support of one of Examples 2-6 (Examples 8-12), mixed with an equal amount of corundum. The composition of the articles is summarized in Table 2.

[0305] Example 13. Reference Pt / Pd catalyst product

[0306] Catalyst articles were prepared from the powder of Example 1B. To prepare the articles, a suitable powder sample (fresh) was loaded into a test bed. The total volume of the test bed was 1 ml, with two equal parts: a bottom and a top, as shown. Figure 5 As shown. The top layer is filled with 2% Pt / Pd (2:1 Pt / Pd) on alumina of Example 1B, and the bottom of the test bed is filled with a reference lanthanum-containing zirconium oxide support without additional dopants. The composition of the products is summarized in Table 2.

[0307] Example 14. Pt / Pd catalyst products

[0308] Catalyst articles were prepared from the powder of Example 1B. To prepare the articles, a suitable powder sample (fresh) was loaded into a test bed. The total volume of the test bed was 1 ml, with two equal parts: a bottom and a top, as shown. Figure 5 As shown. The top layer was filled with 2% Pt / Pd (2:1 Pt / Pd) on alumina of Example 1B, and the bottom of the test bed was filled with Ce / Mn / La / ZrO2 support of Example 4. The composition of the product is summarized in Table 2.

[0309] Table 2. Layer composition of the articles in Examples 7-14

[0310]

[0311] Example 15: Reactor Ignition Test

[0312] Under steady-state conditions, the hydrocarbon (HC) and carbon monoxide (CO) ignition of products from Examples 7-12 (fresh and aged) and 13 and 14 (fresh) in a reactor was evaluated. The gas feed consisted of 1250 ppm CO, 100 ppm (C1-based) ethylene, 300 ppm (C1-based) a 2:1 decane-toluene mixture, 180 ppm nitric oxide, 10% carbon dioxide, 10% water vapor, and 10% oxygen (O2). For steady-state ignition, a 3-minute step-equilibration time was used, plus a 30-second sampling time at temperatures ranging from 135 to 400 °C. The first ignition test was considered as degreening of the sample, and a second ignition test was then recorded.

[0313] As a measure of the performance of fresh and aged catalysts, CO(T) was determined. 50 _CO) and HC(T) 70 _HC) ignition temperature and NO2 yield. Table 3 provides CO(T) ignition temperature and NO2 yield. 50 _CO) and HC(T) 70 The ignition temperature of HC indicates that all articles of the present invention show improved HC conversion for both fresh and aged samples.

[0314] While Ce-Mn impregnated on an alumina support (Example 8) provided superior HC performance compared to Example 7 (reference article), the use of a lanthanum-containing zirconium oxide support (Examples 9-12) instead of an alumina support further improved HC performance, both fresh and aged. Without being bound by theory, this demonstrates a Mn-Zr synergistic effect that favors improved HC performance. Surprisingly, the presence of cerium and copper (Example 12) increased the HC ignition temperature compared to samples with Cu and Mn, Mn only, or Ce and Mn (Examples 11, 9, and 10, respectively).

[0315] While the reference catalyst article containing a Pt / Pd impregnated alumina support (Example 13) provides improved HC / CO performance compared to Example 7 (reference article), the addition of cerium dioxide and manganese to a lanthanum-containing zirconium oxide support (Example 14) further and surprisingly enhances the HC performance (Table 3).

[0316] Table 3. HC / CO ignition (L / O) temperature

[0317]

[0318]

[0319] As a further performance metric, NO2 yield was evaluated at an inlet temperature of 300°C. Data provided in Table 4 show that all inventive articles, whether fresh or aged, provided significantly higher NO2 yields than the reference article (Example 7). The synergistic effect of Mn-Zr on HC ignition also contributes to the increased NO2 yield. This increased NO2 yield is expected to benefit downstream SCR catalysts, as shown in Table 4. Furthermore, this synergistic effect enhances the anti-aging stability of NO2, which is not present in Ce-Mn on alumina. Additionally, the addition of Cu to the Mn / La-Zr support (Examples 11 and 12) resulted in increased CO conversion for both fresh and aged applications. However, surprisingly, the addition of Cu impaired HC conversion and NO2 yield compared to Examples 9 and 10.

[0320] Table 4. NO2 yield at 300℃

[0321]

[0322]

[0323] As a further performance measurement standard for Examples 13 and 14, NO2 yield was evaluated at an inlet temperature of 225°C. Data provided in Table 5 demonstrate that the inventive article of Example 14, even with Pt / Pd on an alumina support as the top layer, provides a significantly higher NO2 yield than the reference article (Example 13).

[0324] Table 5. NO2 yield at 225℃

[0325]

[0326] Example 16: Ignition test using a formaldehyde reactor

[0327] Formaldehyde emissions from automobile exhaust are now regulated in the United States. Therefore, the performance of the products of Examples 7-12 was evaluated according to the protocol of Example 15, but with formaldehyde (150 ppm) added to the feed gas. The samples of Example 15 were cooled only in an N2 atmosphere from the second L / O run prior to the ignition test. Data are provided in Table 6.

[0328] Table 6. HC / CO ignition (L / O) temperature and NO2 yield at 300℃

[0329]

[0330]

[0331] As shown in Table 6, a similar trend to that observed in Example 15 was observed; that is, all the inventive articles showed improved HC conversion in both fresh and aged conditions and provided significantly higher NO2 yields than the reference article (Example 7). The addition of Mn to the La-containing zirconia support was beneficial to both HC conversion and NO2 yield.

[0332] Examples 23-28

[0333] Several different carriers in powder form, other than reference B (Example 16), were also evaluated. The sample preparation process was similar to that of Example 2, except for the dopants and carriers. Table 7 lists detailed descriptions of the various powder samples used in this new set of experiments; all carriers were pre-formed (commercially available).

[0334] Table 7. Catalyst product: 1% Pt / Pd (Pt / Pd = 2 / 1), on various supports.

[0335] 23 (Refer to E) <![CDATA[1% 2:1 Pt / Pd on La / ZrO₂]]> <![CDATA[La / ZrO2: approximately 9% La, 91% Zr]]> 24 <![CDATA[1% 2:1 Pt / Pd and 10% Y on ZrO₂]]> <![CDATA[Y / ZrO2: about 10% Y, 90% Zr]]> 25 <![CDATA[1% 2:1 Pt / Pd and 10% Si on ZrO₂]]> <![CDATA[Si / ZrO2: about 10% Si, 90% Zr]]> 26 <![CDATA[1% 2:1 Pt / Pd and 24% Mn on ZrO₂]]> <![CDATA[Mn / ZrO2: about 24% Mn, 76% Zr]]> 27 <![CDATA[1% 2:1 Pt / Pd and 5% Si on TiO2]]> <![CDATA[Si / TiO2: about 5% Si, 95% Ti]]> 28 <![CDATA[1% 2:1 Pt / Pd and 5% Si on Al2O3]]> <![CDATA[Si / Al₂O₃: about 5% Si, 95% Al]]>

[0336] The powder sample preparation and testing procedures were the same as in Example 15. The results are listed in Tables 8 to 11.

[0337] Table 8. HC / CO ignition (L / O) temperature and NO2 yield at 300℃ and 250℃ (fresh and aged samples)

[0338]

[0339] From Table 8 and Figure 6 See, Y on the ZrO2 support (Example 24 of the present invention) is superior to La / ZrO2 in terms of CO / HC L / O and NO2 yields, whether it is a fresh sample or an aged sample.

[0340] Table 9. HC / CO ignition (L / O) temperature and NO2 yield at 300℃ and 250℃ (fresh and aged samples)

[0341]

[0342] From Table 9 and Figure 7 See, Si on ZrO2 support (Example 25 of the present invention) also outperforms La / ZrO2 in terms of CO / HC L / O and NO2 yields, whether it is a fresh sample or an aged sample.

[0343] Table 10. HC / CO ignition (L / O) temperature and NO2 yield at 300℃ and 250℃ (fresh and aged samples)

[0344]

[0345] From Table 10 and Figure 8 As you can see, Mn on the ZrO2 support (Example 26 of this invention) outperforms La / ZrO2 in terms of CO / HC L / O and NO2 yields, especially NO2 yield, regardless of whether the sample is fresh or aged. The sample of Example 26 also exhibits excellent NO2 performance stability between fresh and aged samples.

[0346] Table 11. HC / CO ignition (L / O) temperature and NO2 yield at 300℃ and 250℃ (fresh and aged samples)

[0347]

[0348] From Table 11 and Figure 9 See, Si on TiO2 support (Example 27 of the present invention) is also superior to La / ZrO2 in terms of CO / HC L / O and NO2 yield, especially NO2 yield, whether it is a fresh sample or an aged sample.

[0349] Table 12. HC / CO ignition (L / O) temperature and NO2 yield at 300℃ and 250℃ (fresh and aged samples)

[0350]

[0351] Similarly, from Table 12 and Figure 10 See, Si on the Al2O3 support (Example 28 of this invention) has better yields in CO / HC L / O and NO2 than La / ZrO2, whether it is a fresh sample or an aged sample.

[0352] In addition to hydrothermal aging, the above samples (fresh, i.e., calcined samples that have not undergone aging) were also sulfated (S) according to the procedure described here:

[0353] ■T=300℃

[0354] ■Total flow rate: 1000 liters / hour

[0355] ■ Feed gas: 10 ppm SO2, 10 vol.% O2, 5 vol.% H2O, balance nitrogen

[0356] ■Duration: 6 hours

[0357] ■ Sulfur exposure: Approximately 1 gram per liter of catalyst

[0358] After sulfation, the same catalyst was exposed to the following conditions to remove sulfur: 700°C for 30 minutes (10% H2O in air).

[0359] After the desulfurization step (de-S), the catalyst was evaluated again under the same ignition scheme shown in Table 13.

[0360] Shown in Table 13 and Figure 11 and 12 The results show that Examples 24 to 28 of the present invention provide better sulfur resistance than Reference Sample Example 23.

[0361] Table 13. HC / CO ignition (L / O) temperature and NO2 yield at 300℃ & 250℃ (fresh samples, after sulfur exposure and desulfurization treatment)

[0362]

[0363] The results in Table 13 show that, following the sulfation and desulfurization steps, all samples of the present invention (Examples 24 to 28) provided better NO2 performance, whether fresh or aged. Furthermore, almost all samples of the present invention exhibited better HC performance. 70 and CO 50 The ignition performance indicates that the sample of the present invention does indeed provide a performance advantage over that of reference example 23.

[0364] In particular, Example 24 of the present invention exhibits minimal performance degradation after the sulfation and desulfurization (re-sulfurization) steps, such as Figure 11 and 12 As shown. The positive impact on NO2 performance after sulfation and desulfurization (desulfurization) is a unique feature of this catalyst.

Claims

1. An oxidation catalyst composition comprising: Platinum group metal PGM composition comprising a combination of palladium and platinum, wherein the weight ratio of palladium to platinum is 1 to 0.1; The first oxide, which is an oxide of yttrium; and The first refractory metal oxide carrier material includes zirconium oxide. The first oxide is loaded on a first refractory metal oxide carrier material, wherein the amount of the first oxide is from 5% to 20% by weight, based on the weight of the first refractory metal oxide carrier material.

2. The oxidation catalyst composition according to claim 1, wherein the first refractory metal oxide support material comprises 1% to 99% by weight of zirconium oxide.

3. The oxidation catalyst composition according to claim 1, wherein the first refractory metal oxide support material comprises alumina, cerium dioxide, titanium dioxide, silica-doped alumina, silica-titanium dioxide, silica-zirconium dioxide, tungsten-titanium dioxide, zirconium oxide-titanium dioxide, zirconium oxide-cerium dioxide, zirconium oxide-alumina, manganese-alumina, lanthanum-zirconium oxide-alumina, magnesium oxide-alumina, zirconium oxide doped with 0.1% to 40% lanthanum oxide, and combinations thereof.

4. The oxidation catalyst composition according to claim 1, wherein: Palladium is loaded onto the first refractory metal oxide support in an amount of 0.1% to 10% by weight, based on the weight of the first refractory metal oxide support; and Platinum is loaded onto the first refractory metal oxide support in amounts ranging from 0.1% to 10% by weight, based on the weight of the first refractory metal oxide support.

5. The oxidation catalyst composition according to claim 1 further comprises a second refractory metal oxide support material.

6. The oxidation catalyst composition according to claim 5, wherein the second refractory metal oxide support material comprises alumina, zirconium oxide, titanium dioxide, cerium dioxide, silica-doped alumina, silica-titanium dioxide, silica-zirconia, tungsten-titanium dioxide, zirconium oxide-titanium dioxide, zirconium oxide-cerium dioxide, zirconium oxide-alumina, manganese-alumina, lanthanum-zirconia, lanthanum-zirconia-alumina, magnesium-alumina, or combinations thereof.

7. The oxidation catalyst composition according to claim 5, wherein the second refractory metal oxide support material comprises metal oxides selected from oxides of cerium, iron, cobalt, zinc, chromium, molybdenum, nickel, tungsten, copper, magnesium, antimony, tin, lead, yttrium, and combinations thereof.

8. The oxidation catalyst composition according to claim 5, wherein the PGM component is loaded on the second refractory metal oxide support material in an amount of 0.1% to 10% by weight, based on the weight of the second refractory metal oxide support material.

9. The oxidation catalyst composition according to claim 5, wherein the second refractory metal oxide support material comprises alumina or zirconium oxide.

10. The oxidation catalyst composition according to claim 9, wherein, based on the weight of zirconium oxide, the zirconium oxide in the second refractory metal oxide support material is doped with lanthanum in an amount of 0.1% to 40% by weight, calculated as oxide.

11. The oxidation catalyst composition according to claim 5, wherein the first oxide is supported on a first refractory metal oxide support material, and the PGM component is supported on a second refractory metal oxide support material.

12. The oxidation catalyst composition according to claim 5, wherein: Based on the weight of the first refractory metal oxide carrier material, the amount of the first oxide loaded on the first refractory metal oxide carrier material is from 5% to 20% by weight, calculated as oxide. and The PGM component is loaded on a second refractory metal oxide support material, wherein the second refractory metal oxide support material is selected from alumina, silica-doped alumina, titanium dioxide, titanium dioxide-doped alumina, zirconium-doped alumina, zirconium oxide, and zirconium oxide doped with 0.1 wt% to 40 wt% lanthanum oxide based on zirconium oxide.

13. The oxidation catalyst composition of claim 12, wherein the first refractory metal oxide support material comprises cerium dioxide, and the amount of the first refractory metal oxide support material is from 1% to 50% by weight based on the weight of the first refractory metal oxide support material.

14. The oxidation catalyst composition according to any one of claims 1-13, wherein the oxidation catalyst composition has a copper content of less than 0.1% by weight.

15. A catalytic article comprising an inlet end and an outlet end having a defined total length, and a catalytic coating disposed on at least a portion thereof, the catalytic coating comprising a first substrate coating and a second substrate coating, wherein: The first substrate coating comprises a first oxide and a first refractory metal oxide carrier material, wherein the first oxide is an oxide of yttrium; and the first oxide is loaded on the first refractory metal oxide carrier material, wherein the first refractory metal oxide carrier material comprises zirconium oxide, and the amount of the first oxide, based on the weight of the first refractory metal oxide carrier material, is from 5% to 20% by weight in terms of oxides. and The second substrate coating comprises a platinum group metal PGM component including a combination of palladium and platinum and a second refractory metal oxide carrier material, wherein the PGM component is loaded on the second refractory metal oxide carrier material, and wherein the weight ratio of palladium to platinum is 1 to 0.

1.

16. The catalyst article of claim 15, wherein the first refractory metal oxide support material comprises 1% to 99% by weight of zirconium oxide.

17. The catalytic article according to claim 15, wherein the first refractory metal oxide support material comprises alumina.

18. The catalyst article of claim 15, wherein, based on the total weight of zirconium oxide, the first refractory metal oxide support material comprises zirconium oxide doped with 0.1% to 40% by weight of lanthanum oxide.

19. The catalyst article according to claim 15, wherein the second refractory metal oxide support material comprises alumina, zirconium oxide, titanium dioxide, cerium dioxide, or a combination thereof.

20. The catalyst article according to claim 15, wherein the second refractory metal oxide support material comprises manganese.

21. The catalyst article according to claim 15, wherein the second refractory metal oxide support material comprises alumina or zirconium oxide.

22. The catalyst article according to claim 21, wherein, based on the total weight of zirconium oxide, the zirconium oxide in the second refractory metal oxide support material is doped with 0.1% to 40% by weight of lanthanum oxide.

23. The catalyst article according to claim 15, wherein the second refractory metal oxide support material is selected from alumina, silica-doped alumina, titanium dioxide, titanium dioxide-doped alumina, zirconium-doped alumina, zirconium oxide, and zirconium oxide doped with 1% to 40% lanthanum oxide based on zirconium oxide.

24. The catalyst article according to claim 15, wherein the total PGM component loading on the catalyst article is 5 g / ft. 3 Up to 200 g / ft 3 .

25. The catalyst article according to claim 15, wherein PGM is loaded on the second refractory metal oxide support material in an amount of 0.5% to 5% by weight, based on the weight of the second refractory metal oxide support material.

26. The catalyst article according to claim 15, wherein: Based on the weight of the first refractory metal oxide support material, the amount of the first oxide loaded on the first refractory metal oxide support material is from 5% to 20% by weight, in terms of oxide, wherein the first refractory metal oxide support material includes zirconium oxide, wherein based on the weight of zirconium oxide, the zirconium oxide is doped with 0.1% to 40% lanthanum oxide. The first refractory metal oxide support material optionally further comprises cerium dioxide, wherein the amount is from 1% to 50% by weight based on the weight of the first refractory metal oxide support material; and The PGM component is loaded on a second refractory metal oxide support material, wherein the second refractory metal oxide support material is selected from alumina, silica-doped alumina, titanium dioxide, titanium dioxide-doped alumina, zirconium-doped alumina, zirconium oxide, and zirconium oxide doped with 0.1 wt% to 40 wt% lanthanum oxide based on zirconium oxide.

27. The catalyst article according to any one of claims 15-26, wherein the first and second substrate coatings have a copper content of less than 0.1% by weight.

28. The catalyst article according to any one of claims 15-26, wherein the first substrate coating is disposed directly on the substrate, and the second substrate coating is disposed on at least a portion of the first substrate coating.

29. The catalyst article according to any one of claims 15-26, wherein the second substrate coating is disposed directly on the substrate, and the first substrate coating is disposed on at least a portion of the second substrate coating.

30. The catalyst article according to any one of claims 15-26, wherein the catalyst article has a partitioned configuration, wherein a first substrate coating is disposed directly on a substrate extending from the outlet end to 20% to 100% of the total length; and a second substrate coating is disposed on a substrate extending from the inlet end to 20% to 100% of the total length.

31. The catalyst article according to any one of claims 15-26, wherein the catalyst article has a partitioned configuration, wherein a second substrate coating is directly disposed on a substrate for a length of 20% to 100% of the total length from the outlet end; and a first substrate coating is disposed on a substrate for a length of 20% to 100% of the total length from the inlet end.

32. A catalyst article comprising an inlet end and an outlet end having a defined total length, and a catalytic coating disposed on at least a portion thereof, said catalytic coating comprising a first substrate coating, a second substrate coating, and a third substrate coating, wherein: The first substrate coating comprises a first oxide and a first refractory metal oxide carrier material, wherein the first oxide is an oxide of yttrium, and the first oxide is loaded on the first refractory metal oxide carrier material, wherein the first refractory metal oxide carrier material comprises zirconium oxide, and the amount of the first oxide, based on the weight of the first refractory metal oxide carrier material, is from 5% to 20% by weight in terms of oxides. The second substrate coating comprises a base metal oxide component including cerium dioxide, zirconium oxide, lanthanum oxide, copper oxide, or a combination thereof, and a second refractory metal oxide carrier material, wherein the base metal oxide component is loaded on the second refractory metal oxide carrier material. and The third substrate coating comprises a platinum group metal PGM component including a combination of palladium and platinum and a third refractory metal oxide carrier material, wherein the PGM component is loaded on the third refractory metal oxide carrier material, and wherein the weight ratio of palladium to platinum is 1 to 0.

1.

33. The catalyst article according to claim 32, wherein the first refractory metal oxide support material comprises 1% to 99% by weight of zirconium oxide.

34. The catalyst article according to claim 32, wherein the second refractory metal oxide support material comprises alumina, zirconium oxide, titanium dioxide, cerium dioxide, silica-doped alumina, titanium dioxide-doped alumina, zirconium-doped alumina, silica-titanium dioxide, silica-zirconium oxide, tungsten-titanium dioxide, zirconium oxide-titanium dioxide, zirconium oxide-cerium dioxide, zirconium oxide-alumina, manganese-alumina, lanthanum-zirconium oxide, lanthanum-zirconium oxide-alumina, magnesium oxide-alumina, or combinations thereof.

35. The catalyst article according to claim 32, wherein the second refractory metal oxide support material comprises alumina.

36. The catalyst article of claim 32, wherein the second refractory metal oxide support material comprises silicon dioxide-doped alumina.

37. The catalyst article of claim 32, wherein the second refractory metal oxide support material comprises zirconium oxide.

38. The catalyst article according to claim 37, wherein, based on the total weight of zirconium oxide, the zirconium oxide in the second refractory metal oxide support material is doped with 0.1% to 40% by weight of lanthanum oxide.

39. The catalyst article according to claim 32, wherein the third refractory metal oxide support material comprises alumina, zirconium oxide, titanium dioxide, cerium dioxide, silica-doped alumina, titanium dioxide-doped alumina, zirconium-doped alumina, silica-titanium dioxide, silica-zirconium oxide, tungsten-titanium dioxide, zirconium oxide-titanium dioxide, zirconium oxide-cerium dioxide, zirconium oxide-alumina, lanthanum-zirconium oxide, lanthanum-zirconium oxide-alumina, magnesium oxide-alumina, or combinations thereof.

40. The catalyst article according to any one of claims 32-39, wherein the first substrate coating is disposed directly on the substrate, and the second substrate coating is disposed on at least a portion of the first substrate coating.

41. The catalyst article according to any one of claims 32-39, wherein the second substrate coating is disposed directly on the substrate, and the first substrate coating is disposed on at least a portion of the second substrate coating.

42. The catalyst article according to any one of claims 32-39, wherein the first substrate coating is disposed directly on the substrate, the second substrate coating is disposed on at least a portion of the first substrate coating, and the third substrate coating is disposed on at least a portion of the second substrate coating.

43. The catalyst article according to any one of claims 32-39, wherein the third substrate coating is disposed directly on the substrate, the second substrate coating is disposed on at least a portion of the third substrate coating, and the first substrate coating is disposed on at least a portion of the second substrate coating.

44. The catalyst article according to any one of claims 32-39, wherein the first substrate coating is disposed directly on the substrate, the third substrate coating is disposed on at least a portion of the first substrate coating, and the second substrate coating is disposed on at least a portion of the third substrate coating.

45. The catalyst article according to any one of claims 32-39, wherein the second substrate coating is disposed directly on the substrate, the third substrate coating is disposed on at least a portion of the second substrate coating, and the first substrate coating is disposed on at least a portion of the third substrate coating.

46. ​​The catalyst article according to any one of claims 32-39, wherein the second substrate coating is disposed directly on the substrate, the first substrate coating is disposed on at least a portion of the second substrate coating, and the third substrate coating is disposed on at least a portion of the first substrate coating.

47. The catalyst article according to any one of claims 32-39, wherein the catalyst article has a partitioned configuration, wherein: The first substrate coating is directly disposed on the substrate from the outlet end to a length of 20% to 100% of the total length; The second substrate coating is disposed on the substrate from the inlet end to a length of 20% to 100% of the total length; and The third substrate coating is disposed on the substrate from the inlet end to a length of 20% to 100% of the total length.

48. An exhaust gas treatment system comprising a catalytic article according to any one of claims 15-47, wherein the catalytic article is downstream of and in fluid communication with a compression-ignition internal combustion engine.

49. A method for treating a gas stream comprising hydrocarbons and / or carbon monoxide and / or NOx, the method comprising contacting the gas stream with a catalyst article according to any one of claims 15-47 or a gas treatment system according to claim 48.

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