Catalyst substrate containing magnetic material suitable for induction heating

Abstract

The present disclosure provides a catalytic substrate comprising a) a ceramic material and b) a magnetic material, the magnetic material being capable of being inductively heated in response to an applied alternating magnetic field. The magnetic material can be associated with the ceramic material in various ways (e.g., dispersed within at least a portion of the ceramic material or contained within the pores of the ceramic material). The present disclosure further provides a catalytic article comprising such a catalytic substrate and at least one catalytic washcoat layer deposited thereon. The catalytic article can be adapted for various purposes depending on the composition of the catalytic washcoat. The present disclosure also includes systems and methods for heating catalytic materials, the system comprising a catalytic article and a conductor for receiving an electric current and generating an alternating electromagnetic field in response thereto.

Description

[Technical Field]

[0001] This application claims priority to U.S. Provisional Application No. 63 / 087,640, filed on 5 October 2020, the contents of which are incorporated herein by reference in their entirety.

[0002] This disclosure relates to catalyst substrates that can be coated with various catalyst compositions, articles for use in treating engine effluent, methods for manufacturing and using such catalyst substrates and articles, and systems for using such catalyst substrates and articles. [Background technology]

[0003] Diesel engine emissions include particulate matter (PM) and nitrogen oxides (NOx). x ), unburned hydrocarbons (HC), carbon monoxide (CO), etc. NO x This term refers to various chemical species of nitrogen oxides, such as nitric oxide (NO) and nitrogen dioxide (NO2). The two main components of exhaust particulate matter are the soluble organic matter fraction (SOF) and the soot fraction. SOF condenses in layers on top of soot and generally originates from unburned diesel fuel and lubricating oil. SOF exists as vapor or aerosol (tiny droplets of condensed liquid) depending on the temperature of the diesel exhaust gas. Soot is mainly composed of carbon particles. The HC content of exhaust gas varies depending on the type of engine and operating parameters, but typically includes various short-chain hydrocarbons such as methane, ethane, and propane, as well as long-chain fuel hydrocarbons.

[0004] Catalysts used to process exhaust gases from internal combustion engines are less effective during relatively low-temperature operating periods, such as the initial cold start period of engine operation, because the engine exhaust temperature is not high enough for efficient catalytic conversion to occur. This is especially true for downstream catalytic components, such as those placed after high-temperature mass filters like SCR catalysts, which can take several minutes to reach their proper operating temperature.

[0005] It has been proposed to use on-board power to heat the catalyst material under startup conditions. Various methods include, for example, preheating the gas by resistance heating of a heating element (see, e.g., U.S. Patent No. 8,479,496 by Gonze et al.; U.S. Patent No. 10,690,031 by Barrientos Betancourt et al.; U.S. Patent No. 6,112,519 by Shimasaki et al.; and U.S. Patent No. 8,156,737 by Gonze et al.); direct resistance heating of a catalyst substrate (see, e.g., U.S. Patent Publication No. US2011 / 0072805 and U.S. Patent No. 10,677,127 by Achenbach et al.); and resistance heating of a conductive element in a ceramic substrate (see, e.g., U.S. Patent No. 10,731,534 by Stiglmair et al.; U.S. Patent No. 10,681,779 by Noro; U.S. Patent No. 9,845,714 by Mori et al.; U.S. Patent No. 8,784,741 by Yoshioka et al.; and U.S. Patent No. 8,329,110 by Kinoshita et al.). In typical approaches, heat is generated by an electric heater, such as a wire wound around the catalyst substrate, a heated grid, or the metal substrate itself acting as a heating element. Several challenges exist for the successful commercialization of such systems, including the relatively high energy consumption required and the relatively low heating efficiency due to the need to initially heat the catalyst substrate. Furthermore, most electric heating designs in this field use metal substrates, which are incompatible with ceramic substrates, which are more widely used as catalyst supports in many systems. Various engine management strategies have also been proposed to address the efficiency degradation during the initial cold start period (see, for example, U.S. Patent No. 10,138,781 by Host et al.; U.S. Patent No. 10,082,047 by Joshi et al.; U.S. Patent No. 9,506,426 by Rems; U.S. Patent No. 10,273,906 by McQuillen et al.; U.S. Patent No. 6,657,315 by Peters et al.; U.S. Patent No. 8,955,473 by Chang; and U.S. Patent No. 9,382,857 by Glugra et al.).

[0006] Induction heating of catalyst bodies has also been studied (see, for example, U.S. Patent Nos. 9,488,085, 10,132,221, and 10,352,214 to Crawford and Douglas). In the current technology, a conductive element embedded in a ceramic substrate is used, and heating is performed by inducing eddy currents in the conductive body. Non-contact induction heating of catalysts has several advantages. There is no need for direct electrical connection to the catalyst body. It incorporates a ceramic support for the catalyst washcoat. However, in the current technology, problems include complicated manufacturing (such as interface fusion between ceramic and metal) and non-uniform heat distribution.

Background Art

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[0007]

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[0008] There remains a need in the art to reduce tailpipe emissions of gaseous pollutants from gasoline or diesel engines, for example, breakthrough emissions generated during cold engine start or other low-temperature operation timing. Means for Solving the Problems

[0009] This disclosure provides a catalyst substrate comprising a base material (e.g., a ceramic material) and a magnetic material that can be inductively heated in response to an applied alternating electromagnetic field. The disclosed subject matter can be used to achieve heating of the catalyst substrate. As a result, heating of one or more layers of catalyst washcoat that can be applied to the substrate to improve the efficiency of catalytic activity can be achieved, for example, during cold starts of an engine, when conventional catalyst systems require several minutes to reach an operating temperature that contributes to catalytic activity. The form of the magnetic material varies, but in some embodiments, the magnetic material is in particulate form that is easily dispersed in the ceramic precursor material used to form the catalyst substrate, or in a form that is easily dispersed, for example, in the pores of the catalyst substrate after the substrate has been formed.

[0010] In some embodiments, a catalyst substrate is provided, comprising a) a ceramic material and b) a magnetic material, wherein the magnetic material can be inductively heated in response to an applied alternating magnetic field. In some embodiments, a catalyst article is provided, wherein a catalyst wash coat is provided on the catalyst substrate mentioned herein.

[0011] Magnetic materials can be associated with catalyst substrates in various ways. For example, at least a portion (e.g., substantially all) of the magnetic material of the catalyst substrate is contained within the substrate. For example, in some embodiments, the magnetic material is dispersed within a ceramic material. Also, in some embodiments, the magnetic material is contained within the pores of a ceramic material.

[0012] The composition of the magnetic material is not particularly limited, as long as the material can be suitably heated, for example, by applying an alternating magnetic field. In some embodiments, the magnetic material includes an electrically insulating material. Also in some embodiments, the magnetic material includes one or more metal oxides. Such metal oxides are selected from transition metal oxides and rare earth metal oxides in some embodiments. Non-limiting examples of such metal oxides include one or more of the oxides of lanthanum, cerium, neodymium, gadolinium, yttrium, praseodymium, samarium, hafnium, tungsten, manganese, iron, cobalt, nickel, copper, and zinc. In some embodiments, the magnetic material is particulate. The particle size varies and may be somewhat limited by, for example, the composition of the substrate (e.g., wall thickness). For example, the magnetic material can be in the form of particles having an average diameter of about 20 nm or more, about 25 nm or more, or about 30 nm or more. In some embodiments, the particles are small enough to enter pores in the substrate (which can be, for example, in the range of micron size). Thus, in some such embodiments, the particles can be less than about 1000 nm, less than about 800 nm, less than about 600 nm, less than about 500 nm, less than about 300 nm, less than about 200 nm, or less than about 100 nm.

[0013] In some embodiments, the ceramic material of the catalyst substrate comprises one or more cordierite, silicon carbide, or aluminum titanate. In some embodiments, the magnetic material is distributed substantially uniformly throughout the catalyst substrate. In some embodiments, the magnetic material is concentrated in one or more specific regions within the catalyst substrate. For example, in some embodiments, the catalyst substrate is cylindrical with a radial center and a radial edge, and the magnetic material is concentrated more in the radial center than at the radial edge, or the magnetic material is concentrated more in the radial center than at the radial edge. Also, in some embodiments, the catalyst substrate has an inlet end and an outlet, and the magnetic material is concentrated more at the inlet end than at the outlet end, or the outlet end than at the inlet end.

[0014] The catalyst substrate is, for example, in some embodiments, a monolithic flow-through substrate having a plurality of parallel gas flow channels open to fluid flow. As another example, the catalyst substrate is a wall-flow substrate having first and second ends and a plurality of parallel gas flow channels, wherein a portion of the plurality of parallel gas flow channels are closed at the first end and open at the second end, and the plurality of parallel gas flow channels are alternately open at the first end and closed at the second end.

[0015] Catalyst washcoats that can be suitably used in the catalyst substrates provided herein can vary widely, for example, depending on the desired function of the resulting catalyst article. In some embodiments, the catalyst washcoat is used for oxidation of carbon monoxide, oxidation of hydrocarbons, NO x oxidation, NO x reduction, ammonia oxidation, NO x selective catalytic reduction, NO x storage / reduction, oxygen storage, soot combustion or oxidation, and water-gas shift. The catalyst article is, for example, a diesel oxidation catalyst (DOC), a catalyzed soot filter (CSF), a lean NO x trap (LNT), a selective catalytic reduction (SCR) catalyst, an SCR catalyst on filter (SCRoF), ammonia oxidation (AMO x ) catalyst, NO x absorbent, or a three-way catalyst (TWC).

[0016] This disclosure further provides a system comprising, in some embodiments, a catalyst article described herein (including a ceramic material and a magnetic material, the magnetic material being capable of induction heating in response to an applied alternating magnetic field), and a conductor that receives an electric current and generates an alternating electromagnetic field in response, wherein the conductor is positioned such that the generated alternating electromagnetic field is applied to at least a portion of the magnetic material. In some embodiments, the conductor is in the form of at least one coil of conductive wire surrounding at least a portion of the catalyst article. In some embodiments, the system may further include a power source electrically connected to the conductor to supply an alternating current to it. In some embodiments, the system may further include a temperature sensor positioned to measure the temperature of a gas entering the catalyst article, and a controller communicating with the temperature sensor, the controller being adapted to control the current received by the conductor so that the controller can energize the conductor when induction heating of the catalyst substrate is desired.

[0017] This disclosure further provides a method for treating emissions from an internal combustion engine, comprising treating the exhaust gas generated from the internal combustion engine in an emissions treatment system comprising a catalyst article described herein (including a ceramic material and a magnetic material, wherein the magnetic material can be inductively heated in response to an applied alternating magnetic field) in fluid communication with the engine. In some embodiments, the engine may be a gasoline engine, a diesel engine, a hybrid electric engine, or a natural gas engine.

[0018] These and other features, aspects, and advantages of this disclosure will become apparent by reading the following detailed description together with the accompanying drawings, which are briefly described below. The disclosed subject matter includes any combination of two, three, four, or more of the embodiments described above, and any combination of any two, three, four, or more features or elements provided in this disclosure, and this specification consists of such combinations of features or elements, whether or not such features or elements are expressly combined in the description of a particular embodiment of this specification. This disclosure is intended to be read holistically, and unless explicitly indicated in its context, any separable features or elements of the disclosed subject matter should be considered as being intended to be combined in any of its various aspects and embodiments. Other aspects and advantages of this disclosure will become apparent from the following description. [Brief explanation of the drawing]

[0019] To provide an understanding of embodiments of this disclosure, refer to the accompanying drawings. These drawings are not necessarily drawn to a specific scale, and reference numbers refer to components of exemplary embodiments of this disclosure. The drawings are illustrative and should not be construed as limiting this disclosure. [Figure 1] Figure 1A is a partial cross-sectional view of the catalyst substrate perpendicular to the flow direction, showing the flow channel opening 10, the substrate wall 12, and the magnetic particles 20 dispersed on the wall surface.

[0020] Figure 1B is a partial cross-sectional view of the catalyst substrate perpendicular to the flow direction, showing the channel opening 10, the substrate wall 12, and the magnetic particles 20 dispersed in the pores of the substrate. [Figure 2] Figures 2A and 2B depict embodiments of a substrate containing the disclosed magnetic material, showing that the magnetic material is distributed in the longitudinal direction of the substrate. [Figure 3] Figure 3 illustrates one embodiment of the disclosed substrate containing a magnetic material, showing that the magnetic material is distributed in the radial direction. [Figure 4]Figure 4A is a perspective view of a honeycomb-type catalyst 2 having an inlet end 6 and an outlet end 8, and a channel 10, comprising a substrate according to the present disclosure, wherein a magnetic material is contained within the substrate. Figure 4B is an enlarged view of Figure 4A, a partial cross-sectional view of 2 along a plane parallel to the end faces of 2 in Figure 4A, and shows an enlarged view of the plurality of gas flow channels 10 shown in Figure 4A, having walls 12 and wash coat layers 14 and 16. [Figure 5] Figure 5 is an enlarged cross-sectional view of Figure 4A, where the honeycomb-shaped substrate carrier in Figure 4A represents the wall flow filter substrate monolith. [Figure 6] Figure 6 is a schematic diagram of one embodiment of an exhaust treatment system 40 utilizing the catalytic articles of this disclosure, comprising an internal combustion engine 42, a diesel oxidation catalyst 44, a catalytic soot filter 46, and a selective catalytic reduction catalyst 48, which are fluidly connected to each other by 43, 45, and 47. [Figure 7] Figure 7 is a schematic depiction of one configuration utilizing the catalyst article 2 of the present disclosure, and shows a conductor 66, a controller 74, a power supply 70, and a temperature sensor 72. [Figure 8] Figure 8 is a schematic diagram of one embodiment of an exhaust treatment system 51 utilizing multiple catalyst articles of the present disclosure, and shows related electrical conductors, controllers, power supplies, and temperature sensors. [Figure 9] Figure 9A is a low-magnification scanning electron microscope image of Example 1 in a cross-section perpendicular to the channel axis (where the black areas represent channels and voids, the gray areas represent cordierite in the substrate wall, and the white areas represent magnetic particles). Figure 9B is a high-magnification scanning electron microscope image of Example 1 in a cross-section perpendicular to the channel axis (where the black areas represent channels and voids, the gray areas represent cordierite in the substrate wall, and the white areas represent magnetic particles). [Figure 10]Figure 10A is a low-magnification scanning electron microscope image of Example 2 in a cross-section perpendicular to the channel axis (where the black areas represent channels and voids, the gray areas represent cordierite in the substrate wall, and the white areas represent magnetic particles). Figure 10B is a high-magnification scanning electron microscope image of Example 2 in a cross-section perpendicular to the channel axis (where the black areas represent channels and voids, the gray areas represent cordierite in the substrate wall, and the white areas represent magnetic particles). [Figure 11] Figure 11 is a chart showing the temperature as a function of time when a magnetically activated ceramic substrate is exposed to an alternating magnetic field generated by an AC potential applied to a wire coil surrounding a component (control data was obtained using a standard ceramic substrate that is not magnetically activated). [Figure 12] Figure 12 shows a series of infrared thermal images taken every 30 seconds while exposing a magnetically activated ceramic substrate to an alternating magnetic field generated by an AC potential applied to a wire coil surrounding the component. [Figure 13] Figures 13A and 13B are infrared thermal images collected when a conductive metal substrate is exposed to an alternating magnetic field generated by an AC potential applied to a wire coil surrounding the component. [Modes for carrying out the invention]

[0021] The present disclosure will be described in more detail below. While the disclosure herein has described specific embodiments, these embodiments should be understood to be merely illustrative of the principles and applications of the present disclosure. It will be apparent to those skilled in the art that various modifications and variations can be made to the methods and apparatus of the subject matter without departing from the spirit and scope of the present disclosure. Accordingly, the present disclosure is intended to include modifications and variations that fall within the scope of the appended claims and their equivalents. It should be understood that the present disclosure is not limited to the details of the configuration or method steps described below. Other embodiments of the present disclosure are possible and can be implemented or performed in various ways. The same reference numerals refer to the same elements throughout. As used herein and in the claims, the singular forms "a," "an," and "the" also include the plural of such object unless the context clearly indicates otherwise.

[0022] This disclosure relates to a catalyst article comprising, generally, a substrate and one or more catalyst compositions in the form of a wash-coat layer provided thereon. The substrate typically provides a plurality of walls to which the catalyst composition is coated and adhered, thereby functioning as a carrier for the catalyst composition. The substrate is of a type commonly used in the manufacture of automotive catalysts and is typically composed of a metal or ceramic honeycomb structure. Both the substrate and the catalyst composition(s) are described in further detail below herein.

[0023] definition In this book, the articles "a" and "an" refer to one or more grammatical objects (e.g., at least one). Any scope referred to in this book is inclusive. The term "about" used throughout is used to describe and account for small variations. For example, "about" may mean that a number may be modified by ±5%, ±4%, ±3%, ±2%, ±1%, ±0.5%, ±0.4%, ±0.3%, ±0.2%, ±0.1%, or ±0.05%. All numbers, whether explicitly indicated or not, are modified by the term "about." Numbers modified by the term "about" include that particular value. For example, "about 5.0" includes 5.0.

[0024] "Reduction" means a decrease in quantity, caused by any means.

[0025] "AMO x A "selective ammonia oxidation catalyst" is a catalyst that contains one or more metals (usually Pt, but not limited to Pt) suitable for converting ammonia to nitrogen, and a selective catalytic reduction (SCR) catalyst.

[0026] The term “related” means, for example, “equipped with,” “connected,” or “communicated,” for example, “electrically connected,” or “fluidly connected,” or otherwise connected to perform a function. The term “related” may also mean directly or indirectly related, for example, through one or more other articles or elements.

[0027] "Average particle size" is synonymous with D50, meaning that half of the particles in a population have a particle size greater than this point, and the other half have a particle size less than this point. Particle size refers to primary particles. Particle diameter can be measured by laser light scattering using a dispersion or dry powder, for example, according to ASTM method D4464. The D90 particle size distribution indicates that 90% (by number) of particles have a ferret diameter below a certain size, as measured by scanning electron microscope (SEM) or transmission electron microscope (TEM) for submicron-sized particles, and by particle size analyzer for particles containing a support (micron size).

[0028] A "catalyst" is a substance that accelerates a chemical reaction. Catalysts include "catalytically active species" and "carriers" that support or hold those active species. For example, zeolites are carriers that support palladium catalytically active species. Similarly, refractory metal oxide particles can serve as carriers for platinum group metal catalytic species. Since catalytically active species accelerate chemical reactions, they are also called "promoters." For example, current palladium-containing rare earth metal components are sometimes referred to as Pd-promoted rare earth metal components. A "promoted rare earth metal component" is a rare earth metal component to which catalytically active species have been intentionally added.

[0029] In the disclosed subject matter, the term "catalytic article" means an article comprising a substrate having a catalytic coating composition.

[0030] As used herein and in the claims, the term “composed” is intended to be unrestricted, like the terms “include” or “contain.” The term “composed” is not intended to exclude any other possible articles or elements. The term “composed” may be equivalent to “conformed.”

[0031] "CSF" refers to a wall-flow monolithic catalytic soot filter. A wall-flow filter consists of alternating inlet and outlet channels, with the inlet channel being blocked at the outlet end and the outlet channel being blocked at the inlet end. The exhaust gas flow containing soot that enters the inlet channel is forced to pass through the filter wall before exiting through the outlet channel. In addition to filtering and regenerating soot, the CSF can carry an oxidation catalyst to oxidize CO and HC to CO2 and H2O, or NO to NO2 to accelerate the downstream SCR catalytic reaction, or promote the oxidation of soot particles at low temperatures. The SCR catalyst composition can also be coated directly onto the wall-flow filter, which is called SCRoF.

[0032] "DOC" refers to a diesel oxidation catalyst that converts hydrocarbons and carbon monoxide in the exhaust gas of a diesel engine. Generally, a DOC includes one or more platinum group metals, such as palladium and / or platinum, a support material such as alumina, a zeolite for HC storage, and optionally, accelerators and / or stabilizers.

[0033] As used in this book, the term "exhaust gas treatment system" refers to a combination of two or more catalytic components, for example, a combination of the LNT-LT-NA disclosed herein with one or more additional catalytic components (which may be, for example, CSF, DOC, or selective catalytic reduction (SCR) catalyst articles).

[0034] Generally, the term "effective" means effective in terms of mass or moles with respect to the defined catalytic activity or storage / release activity, for example, from about 35% to 100%, for example, from 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%.

[0035] The term “exhaust flow” or “exhaust gas flow” refers to a combination of flowing gases that may contain solid or liquid particulate matter. This flow may contain gaseous components, such as the exhaust from a lean-burn engine, and may also contain certain non-gaseous components, such as droplets and solid particulate matter. The exhaust gas flow from a combustion engine typically consists of combustion products (CO2 and H2O), incomplete combustion products (carbon monoxide (CO) and hydrocarbons (HC)), and nitrogen oxides (NO). x ), flammable and / or carbonaceous particulate matter (soot), and further including unreacted oxygen and nitrogen. As used in this document, the terms “upstream” and “downstream” refer to the relative direction according to the flow of engine exhaust gases from the engine to the tailpipe, with the engine being upstream and the tailpipe and pollution mitigation items such as filters and catalysts being downstream from 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 (area) is upstream of the downstream zone. The upstream zone may be close to the engine or manifold, and the downstream zone may be far from the engine or manifold.

[0036] The term "fluid-connected" is used to mean that articles are located on the same exhaust line, that is, that a common exhaust flow passes through articles that are in fluid connection with each other. Articles in a fluid-connected state may be adjacent to each other in the exhaust line. Alternatively, fluid-connected articles may be separated by one or more articles, also called a "washcoat monolith."

[0037] In the disclosed subject matter, the term "functional article" means an article comprising a substrate having a functional coating composition disposed thereon, such as a catalyst and / or adsorbent coating composition.

[0038] As used in this book, "impregnation" or "penetration" means that the catalyst material penetrates the porous structure of the support material.

[0039] The terms “on” and “over” in relation to coating layers can be used as synonyms. The term “directly on” means in direct contact. In some embodiments of the disclosed articles, one coating layer is referred to as being “on” a second coating layer, but such expressions are intended to include embodiments having other intervening layers that do not require direct contact between the coating layers (i.e., “on” is not equivalent to “directly”).

[0040] In this book, the term "promoted" refers to a component intentionally added to a rare-earth metal component, as opposed to an impurity inherent in the rare-earth metal component itself. A "promoter" is a metal that enhances the activity for a desired chemical reaction or function.

[0041] In this book, the term "selective catalytic reduction" (SCR) refers to a catalytic process that reduces nitrogen oxides to dinitrogen (N2) using a nitrogen-based reducing agent.

[0042] When used in this book, the term "nitrogen oxides" or "NO x "NO" refers to nitrogen oxides such as NO, NO2, or N2O.

[0043] In this text, the term "flow" broadly refers to any combination of flowing gases that may contain solid or liquid particulate matter. The term "gas flow" or "exhaust gas flow" refers to the flow of gaseous components, such as exhaust from a combustion engine, which may entrain and contain non-gaseous components such as droplets and solid particulate matter. Exhaust gas flows from a combustion engine typically consist of combustion products (CO2 and H2O), incomplete combustion products (carbon monoxide (CO) and hydrocarbons (HC)), and nitrogen oxides (NO). x ), further comprising flammable and / or carbonaceous particulate matter (soot), and unreacted oxygen and nitrogen.

[0044] "Substantially absent" means "almost or completely absent" or "not intentionally added," and also means present only in trace amounts and / or accidental amounts. For example, in some embodiments, "substantially absent" means less than 2% by mass, less than 1.5% by mass, less than 1.0% by mass, less than 0.5% by mass, 0.25% by mass, or less than 0.01% by mass, based on the mass of the total composition shown.

[0045] As used in this book, the term “substrate” refers to a monolithic material on which a catalyst composition, i.e., a catalyst coating, is typically arranged in the form of a wash coat. In one or more embodiments, the substrate is a flow-through monolith and a monolithic wall-flow filter. Flow-through substrates and wall-flow substrates are also taught, for example, in International Patent Application Publication WO2016 / 070090, which is incorporated herein by reference. The wash coat is formed by preparing a slurry containing a specific solid content (e.g., 30–90% by mass) of catalyst in a liquid, applying it to the substrate, and drying it to provide a wash coat layer. A “monolithic substrate” means a homogeneous, continuous, and integral structure from inlet to outlet. The wash coat is formed by preparing a slurry containing a certain solid content (e.g., 20–90% by mass) of particles in a liquid solvent, applying it to the substrate, and drying it to provide a wash coat layer.

[0046] In this book, the terms "upstream" and "downstream" refer to the relative direction of the engine exhaust gas flow from the engine to the tailpipe, with the engine located upstream and the tailpipe and pollution mitigation components such as filters and catalysts located downstream from the engine.

[0047] As used in this book, the term “washcoat” has the common meaning in the art of a thin adhesive coating of a catalyst or other material applied to a substrate material that has sufficient porosity to allow the passage of the gas flow to be treated, such as a honeycomb substrate. As used in this book, and as described in Heck, Ronald and Farrauto, Robert, Catalytic Air Pollution Control, New York: Wiley-Interscience, 2002, pp. 18-19, a washcoat layer comprises layers of compositionally different materials placed on the surface of a monolithic substrate or on a washcoat layer beneath it. A substrate may have one or more washcoat layers, each washcoat layer may differ in some way (e.g., its physical properties such as particle size or crystallite phase) and / or in its chemocatalytic function.

[0048] Unless otherwise specified, "mass percentage" refers to the entire composition excluding volatiles, i.e., based on the dry solids content. Unless otherwise specified, all parts and percentages are on a mass basis.

[0049] All methods described herein may be performed in any appropriate order unless otherwise specified herein or unless the context clearly contradicts it. Any and all specific examples or illustrative expressions (e.g., "etc.") described herein are intended solely to better illustrate the materials and methods and, unless otherwise claimed, are not intended to limit their scope. Nothing in this specification should be construed as indicating that non-claimed elements are essential to the implementation of the disclosed materials and methods. All U.S. patent applications, pre-grant publications and patents referenced herein are incorporated herein by reference in their entirety.

[0050] Base material According to this disclosure, the substrate generally comprises a substrate "base material" and a magnetic material that can be inductively heated in response to an applied alternating electromagnetic field. The use of inductive heating for the magnetic material within the catalyst substrate is a method of directing heat to the catalyst material present on the surface of the catalyst substrate (for example, in the form of a catalyst wash coat), thereby enabling it to reach an operating temperature that contributes to catalytic activity in a short time, such as during a cold start of an engine. By enabling the catalyst material to reach the desired temperature quickly, breakthrough of gaseous contaminants that is normally associated with catalyst operation at low temperatures can be minimized.

[0051] The “base material” can be diverse and generally any material that can construct a substrate and that can disperse magnetic material (for example, during the manufacturing / formation of the substrate). Some exemplary base materials suitable for use in accordance with this disclosure are ceramics. Ceramic materials used to construct a substrate include any suitable refractory material, such as cordierite, mullite, cordierite-α-alumina, silicon nitride, zircon mullite, spodumene, alumina-silica-magnesia, zircon silicate, sillimanite, magnesium silicate, zircon, petalite, α-alumina, aluminosilicate, etc.

[0052] "Magnetic material" can include ferromagnetic materials, ferrimagnetic materials, and paramagnetic materials. While magnetic materials can take various forms, in some embodiments, the magnetic material is in particulate form that can be easily dispersed in a composition containing a substrate precursor (e.g., a ceramic precursor) that forms the substrate. In other embodiments, the magnetic material is in particulate form that can easily penetrate / impregnate the pores in the as-formed substrate.

[0053] In some embodiments, particle size can directly affect the type of magnetic material that can be used. In other words, magnetic particles in some embodiments can generally include any material, as long as the particles exceed a certain size threshold (suitable for producing the desired effect). In some embodiments, the useful particle size is limited by the dimensions of the substrate. In some embodiments, the particles must be below a certain threshold (for example, if introduced into pores in an as-formed substrate, it is advantageous that the particle size is less than the average size of the pores in the substrate). In some embodiments, the particles can be formed from at least partially conductive material, but in some embodiments, particles containing non-conductive material (e.g., particles made of essentially non-conductive material) are preferred. In some embodiments, any material that can be inductively coupled via eddy currents (e.g., metal particles, wire pieces, and other metal-containing materials) can be used for this purpose.

[0054] The morphology (e.g., shape and size) of the magnetic material particles can vary. In some embodiments, the particles are nanoparticles, but are not limited to them. Therefore, in some embodiments, the average particle size is about 100 nm or less (e.g., about 1 nm to about 100 nm). In some embodiments, the particles are at the smaller end of this range. For example, in some embodiments, the average particle size is about 60 nm or less (e.g., about 1 nm to about 60 nm) or about 50 nm or less (e.g., about 1 nm to about 50 nm). In some embodiments, the particles are at the larger end of this range, for example, about 60 nm or more (e.g., about 60 nm to about 100 nm or about 80 nm to about 100 nm). In some embodiments, the particles are even larger, for example, about 100 nm or larger (e.g., about 100 nm to about 500 nm, about 100 nm to about 400 nm, about 100 nm to about 300 nm, about 100 nm to about 200 nm, or about 100 nm to about 150 nm). In some embodiments, better heating is provided by larger particles, and therefore, in such embodiments, the average particle size is about 25 nm or larger. As mentioned above, it should be noted that the appropriate particle size may depend on the method of manufacturing the catalyst article described herein (i.e., whether the particles are added to the substrate precursor and extruded directly together with the substrate, or added after the manufacturing of the substrate).

[0055] In some embodiments, the particles are substantially monodisperse, but this disclosure is not limited thereto. In some embodiments, the particles may exhibit a bimodal particle size distribution. In some embodiments, the magnetic material includes nanoparticle magnetic materials, which are referred to as superparamagnetic materials. However, in some embodiments, the magnetic material may be used in the form of nanowires, nanotubes, or sheets, as long as the magnetic material is dispersed within the substrate during its manufacture.

[0056] Any material that can be inductively heated in the presence of an alternating electromagnetic field can be used, but advantageous magnetic materials include materials containing transition metals or rare earth metals, such as oxides containing such transition metals or rare earth metals. “Rare earth metals” refer to scandium, yttrium, lanthanum series, or their oxides, as defined in the periodic table. Examples of rare earth metals include lanthanum, cerium, neodymium, gadolinium, yttrium, praseodymium, samarium, hafnium, and mixtures thereof. Examples of transition metals that can be used as components of magnetic materials include tungsten, manganese, iron, cobalt, nickel, copper, and zinc. Mixtures of transition metals and rare earth metals can be used in the same magnetic material. Many oxide forms of magnetic metals are used in this disclosure because metal oxides tend to be very stable at operating temperatures often associated with catalytic systems used to treat exhaust from engines.

[0057] The substrates disclosed herein, comprising both a base material and a magnetic material, can be manufactured in various ways. Two examples of methods for manufacturing such substrates are referred to herein as the “combination” method and the “impregnation” method, and are described in further detail below. Briefly, the combination method involves extruding a composition containing both a base material precursor and a magnetic material to form a substrate, while the impregnation method involves manufacturing a substrate containing the base material and impregnating the substrate with the magnetic material (for example, by introducing the magnetic material into the pores within the substrate). These methods are not mutually exclusive, and it should be noted that in some embodiments, a substrate containing the magnetic material is manufactured via the combination method, and this substrate (containing the first magnetic material) is then subjected to the impregnation method to introduce a second magnetic material (which may be the same as or different from the first magnetic material). Such methods are advantageous in some embodiments for maximizing the amount of magnetic material in relation to the substrate.

[0058] In some embodiments, a substrate containing a magnetic material is manufactured by a combination method as follows: The magnetic material is combined with a composition (e.g., a solution or slurry) of a base material precursor (e.g., a ceramic precursor). The magnetic material is typically (but not necessarily) in the form of particulate material. Combination methods include mixing, grinding, and shaking to promote overall dispersion of the magnetic material. The resulting mixture is molded into a substrate (e.g., by extrusion or pouring into a mold, followed by firing and drying). General methods for manufacturing ceramic substrates are known. For example, these are described in Corning U.S. Patents 5,314,650, 5,403,787, 6,455,124, 8,673,206, and 9,808,794, which are incorporated herein by reference in their entirety. The resulting substrate (properly molded, fired, and dried) generally contains the magnetic material dispersed within the base material. The dispersion may or may not be homogeneous within the base material.

[0059] Figure 1A shows a portion of a cross-section of a substrate manufactured according to one embodiment of the combination method. Black represents the base material, and white dots represent the magnetic material. In Figure 1A, the exemplary substrate includes a channel 10 formed by walls 12 extending through the substrate from the upstream end to the downstream end, with the magnetic material 20 dispersed within the walls 12. This figure can be better understood by referring to Figures 4A, 4B, and 5. Figures 4A, 4B, and 5 depict exemplary catalysts in which a washcoat composition is placed on a substrate (which can be, for example, a flow-through substrate or a wall-flow filter, as will be described in more detail below herein).

[0060] In another embodiment, a substrate containing a magnetic material is manufactured by an impregnation method as follows: First, a substrate comprising a base material is manufactured by any method known in the art (e.g., extrusion or pouring into a mold) as outlined, for example, in the Corning Corporation reference patent incorporated herein by reference. Separately, a magnetic material is prepared and combined with the manufactured substrate (before or after drying and firing the substrate). The magnetic material can be introduced in various forms, for example, as a solution, dispersion, suspension, or in solid form. The magnetic material penetrates, for example, into the pores of the substrate, such as so that the magnetic material is contained within the pores of the substrate. The impregnation method may further include shaking, application of pressure, heating, etc., to facilitate the penetration of the magnetic material into the pores. The resulting substrate (after being properly molded, fired, and dried) generally contains the magnetic material dispersed in the pores of the base material. This dispersion may or may not be uniform within the pores.

[0061] Figure 1B shows a portion of a cross-section of a substrate manufactured according to one embodiment of the impregnation method. Black represents the base material, the white irregular areas represent pores within the base material, and the black dots within the pores represent the magnetic material. The exemplary substrate includes a channel 10 formed by a wall 12 extending through the substrate from the upstream end to the downstream end, with the magnetic material 20 dispersed within the pores of the wall 12. Again, this figure can be better understood by referring to Figures 4A, 4B, and 5. Figures 4A, 4B, and 5 depict exemplary catalysts in which a washcoat composition is placed on a substrate (which can be, for example, a flow-through substrate or a wall-flow filter, as will be described in further detail below herein).

[0062] In some embodiments, the distribution of magnetic material within the substrate (within the base material or within the pores of the base material) is relatively uniform throughout the substrate. While this disclosure primarily assumes a substantially uniform distribution of magnetic material throughout the substrate, it should be noted that in some embodiments, it may be desirable to incorporate the magnetic material only within a portion of the substrate, such that the substrate comprises regions consisting of the base material without added magnetic material and regions consisting of the base material and the added magnetic material. In some embodiments, the magnetic material is incorporated both within the substrate / within the pores of the substrate and on the surface of the substrate (e.g., the entire substrate and on the walls). In other embodiments, it is incorporated only within the substrate (or substantially only within the substrate / within the pores of the substrate).

[0063] In some embodiments, the concentration of magnetic material varies throughout the substrate. In some embodiments, the magnetic particles are distributed (within the base material or within the pores of the base material) such that a higher concentration exists at the inlet end of the substrate than at the outlet end (longitudinal heterogeneity). Two examples of such distribution profiles are shown in Figures 2A and 2B, where 2 is the substrate, the "maximum" amount of magnetic particles is shown on the left side of the substrate (understood to be the inlet end), and the "minimum" amount of magnetic particles is shown on the right side of the substrate (understood to be the outlet end). The exact shape of the maximum-to-minimum curve / line along the length of the substrate in the embodiments of Figures 2A and 2B can vary and is not limited to the illustrated shape. For example, the "maximum" distribution may extend further along the length of the substrate from the inlet than is depicted. Figures 2A and 2B are simply presented as examples of variations in magnetic material concentration along the longitudinal direction of the substrate. The "maximum" and "minimum" values ​​can vary, and the minimum value can be a positive value (i.e., the substrate can contain a certain amount of magnetic material less than the "maximum" within a given region). In other embodiments, the "minimum" value is 0 (i.e., the substrate does not contain magnetic particles within the specified region).

[0064] In some embodiments, the magnetic particles are distributed radially such that the concentration is higher in the center of the substrate's cross-section than on the outside of the substrate, as commonly shown in Figure 3. As shown, the concentration gradually decreases, with the “maximum” concentration in the center of the circular cross-section of the substrate and the “minimum” concentration on the outside of the circular cross-section (radial non-uniformity). Such a cross-section can be consistent / uniform along the length of the substrate or can vary as commonly described with respect to Figures 2A and 2B (i.e., in some embodiments, the loading of magnetic material can vary in both the longitudinal and radial directions). Again, Figure 3 is provided simply as an example of the variability of magnetic material concentration in the radial or axial direction of the substrate. The exact variation of the distribution from the inside to the outside of the cross-section can vary (e.g., the exact shape of the curve drawn in Figure 3 may vary). The “maximum” and “minimum” values ​​can vary, and the minimum value can be a positive value (i.e., the substrate can contain less than the “maximum” amount of magnetic material in a given area). In other embodiments, the “minimum” value is 0 (i.e., the substrate does not contain magnetic particles in a given area).

[0065] The exact amount of magnetic material associated with a given substrate (e.g., incorporated within the base material, incorporated within the pores of the base material, and / or on one or more surfaces) can vary. Typically, there are some lower limits on the amount of magnetic material useful for effectively inducing the induction heating of the substrate and, consequently, the catalyst composition deposited thereon, in response to an applied alternating electromagnetic field. Generally, heating efficiency increases with increasing concentration of magnetic material. However, there are some upper limits on the amount of magnetic material that can be effectively incorporated into the substrate structure without significantly impairing the productivity of the substrate (e.g., by adversely affecting the extrusion capacity of the composition) or significantly impairing the physical properties of the resulting substrate (e.g., strength).

[0066] The substrates manufactured according to this disclosure can take various forms, including, for example, monolithic flow-through substrates having multiple fine, parallel gas channels extending from an inlet to an outlet surface of the substrate, with these channels open to the fluid flow. The substantially straight channels from inlet to outlet are defined by walls coated with a catalyst material as a wash coat, such that the gas flowing through the channels comes into contact with the catalyst material. The channels of the monolithic substrate are thin-walled channels that can have any suitable cross-sectional shape, such as trapezoidal, rectangular, square, sinusoidal, hexagonal, elliptical, or circular. Such structures can have gas inlet openings (i.e., "cells") with a cross-sectional area of ​​approximately 60 to approximately 1200 or more (cpsi), more typically about 300 to approximately 600 cpsi. The wall thickness of the flow-through substrates can vary, with a typical range being between 0.002 inches and 0.1 inches. Typical commercially available flow-through substrates are cordierite substrates having a wall thickness of 400 cpsi and 6 mil, or 600 cpsi and 4 mil. However, the disclosed subject matter is understood to be not limited to specific substrate types, materials, or shapes.

[0067] In some embodiments, the substrate may be a wall-flow substrate, where each channel is blocked at one end of the substrate body with a non-porous plug, and the channels are alternately blocked at opposite end faces. This requires that the gas pass through the porous walls of the wall-flow substrate to reach the outlet. Such monolithic substrates can contain up to about 700 cpsi or more, such as about 100 cpsi to 400 cpsi, e.g., about 200 cpsi to about 300 cpsi. The cross-sectional shape of the cells can vary as described above. Wall-flow substrates typically have wall thicknesses ranging from 0.002 inches to 0.1 inches. Typical commercially available wall-flow substrates are composed of porous cordierite, one example having a wall thickness of 10 mils at 200 cpsi or 8 mils at 300 cpsi, and a wall porosity of 40 to 70%. Other ceramic materials such as aluminum titanate, silicon carbide, and silicon nitride are also used as wall-flow filter substrates. However, it will be understood that the subject matter disclosed is not limited to specific types, materials, or shapes of substrates. It should be noted that, if the substrate is a wall-flow substrate, the associated catalyst composition (e.g., CSF composition) may not only be placed on the surface of the wall but may also penetrate into the pore structure of the porous wall (i.e., partially or completely block the pore openings).

[0068] Figures 4A and 4B show an exemplary catalyst 2 in the form of a flow-through substrate coated with the wash-coat composition described herein. Referring to Figure 4A, the exemplary catalyst 2 is cylindrical in shape and has a cylindrical outer surface 4, an upstream end surface 6, and a corresponding downstream end surface 8 identical to the end surface 6. The catalyst 2 has a plurality of fine, parallel gas channels 10 formed therein. As seen in Figure 4B, the channels 10 are formed by walls 12 and extend through the carrier 2 from the upstream end surface 6 to the downstream end surface 8, and the channels 10 are not obstructed so as to allow a fluid, such as a gas flow, to flow longitudinally through the carrier 2 via the gas channels 10. As is more readily apparent in Figure 4B, the walls 12 are dimensioned and constructed so that the gas channels 10 have a substantially regular polygonal shape. As shown, the catalyst composition can optionally be coated in a plurality of separate layers. In the illustrated embodiment, the catalyst composition consists of both a separate bottom layer 14 attached to the walls 12 of the carrier member and a second separate top layer 16 coated over the bottom layer 14. This disclosure can be implemented with one or more (e.g., two, three, or four) catalyst layers and is not limited to the two-layer embodiment shown in Figure 4B.

[0069] In another embodiment, Figures 4A and 5 show an exemplary substrate 2 in the form of a wall flow filter substrate coated with a washcoat composition. As seen in Figure 5, the exemplary substrate 2 has a plurality of channels 22. The channels are tubularly enclosed by the inner wall 23 of the filter substrate. The substrate has an inlet end 24 and an outlet end 26. The alternating channels are blocked by inlet plugs 28 at the inlet end and outlet plugs 30 at the outlet end, forming a checkerboard pattern with opposing inlets 24 and outlets 26. The gas flow 32 enters through the unplugged channel inlet 34, is stopped by the outlet plug 30, and diffuses through the channel wall 23 (which is porous) to the outlet side 36. The gas cannot pass back to the inlet side of the wall due to the inlet plug 28. Porous wall flow filters used in some embodiments are catalytic in that the wall of the element has one or more catalytic materials on it or contained within it. The catalyst material may fill only the inlet side of the element's wall, only the outlet side, both the inlet and outlet sides, or the wall itself with all or part of the catalyst material. This disclosure includes the use of one or more catalyst material layers located within the wall or on the inlet and / or outlet walls of the element.

[0070] In some embodiments, dispersing the magnetic material directly within the material of the substrate (e.g., a flow-through substrate or a wall-flow filter) or within the pores of the substrate ensures that blockage of the flow channels, which are designed to be open, occurs with little to no effect. Furthermore, such dispersion of the magnetic material allows, in some embodiments, the substrate itself and the catalyst composition on it to be heated substantially uniformly when exposed to an electric field. When the magnetic material is distributed throughout the substrate (e.g., via dispersion into the entire base material or via encapsulation within the pores of the base material), it becomes possible to induce substantially uniform heating of the entire surface of the substrate, and similarly, substantially uniform heating of the catalyst composition on it.

[0071] Catalyst composition The catalyst composition coated onto the substrate can vary without departing from the disclosed subject matter and may include, for example, any catalytic active material commonly used in gasoline or diesel engine emission control systems. For example, the catalytic active material may be for the oxidation of carbon monoxide, hydrocarbons, NO x Oxidation of , oxidation of ammonia, and NO x It can be part of a composition that conforms to one or more of the selective catalytic reductions of the following.

[0072] Such catalytic materials typically comprise one or more catalytic metals impregnated or ion-exchanged in a porous support, with exemplary supports including refractory metal oxides and molecular sieves. In some embodiments, the catalytic metal is selected from base metals, platinum group metals, oxides of base metals or platinum group metals, and combinations thereof. The catalytic materials used in this disclosure can be described based on their function and type, as well as the structure of the material as described above. For example, catalytic materials include diesel oxidation catalysts (DOCs), catalytic soot filters (CSFs), and lean NOx. x Traps (LNT), selective catalytic reduction (SCR) catalysts, filtered SCR catalysts (SCRoF), ammonia oxidation (AMO) x This can be a catalyst or a three-way catalyst (TWC). Furthermore, examples include catalytically active particles adapted for use as a volatile organic hydrocarbon (VOC) oxidation catalyst or a room-temperature hydrocarbon oxidation catalyst.

[0073] DOC or CSF catalysts typically comprise one or more PGM components impregnated onto a metal oxide support such as alumina, and optionally further comprising an oxygen storage component (OSC) such as ceria or ceria / zirconia, and usually achieve oxidation of both hydrocarbons and carbon monoxide.

[0074] LNT catalysts generally consist of one or more PGM components impregnated onto a support, and NO x The catalyst contains components that capture NO (e.g., ceria and / or alkaline earth metal oxides). The LNT catalyst is produced under lean conditions. x It adsorbs NO accumulated under rich conditions xIt can be reduced to nitrogen.

[0075] SCR catalysts are adapted to catalytically reduce nitrogen oxides using a reducing agent in the presence of an appropriate amount of oxygen. The reducing agent can be, for example, hydrocarbons, hydrogen, and / or ammonia. SCR catalysts typically contain a molecular sieve (e.g., zeolite) ion-exchanged with a promoter metal such as copper or iron; exemplary SCR catalysts include FeBEA, FeCHA, and CuCHA.

[0076] A TWC catalyst is a catalyst that has the function of a ternary conversion, substantially simultaneously converting hydrocarbons, carbon monoxide, and nitrogen oxides. Typically, a TWC catalyst contains one or more platinum group metals, such as palladium and / or rhodium, and optionally platinum, along with an oxygen storage component. Under rich conditions, a TWC catalyst usually produces ammonia.

[0077] AMO x The term "catalyst" refers to an ammonia oxidation catalyst, which is a catalyst composed of one or more metals suitable for converting ammonia, and is generally supported on a support material such as alumina or titania. An example of an AMO is shown. x The catalyst contains a copper zeolite in conjunction with a supported platinum group metal (for example, platinum impregnated onto alumina).

[0078] Methods for producing such catalyst compositions often involve impregnating a porous support with a PGM or base metal solution, and / or ion-exchanging a molecular sieve with a metal precursor solution. Such and other methods known for producing catalyst compositions that can be used with substrates containing the disclosed magnetic material are generally known in the art and are described, for example, in U.S. Patent No. 9,138,732 by Bull et al. and U.S. Patent No. 8,715,618 by Trukhan et al. These documents are incorporated in their entirety by reference.

[0079] In some embodiments, the catalyst composition may include magnetic materials (in addition to the magnetic materials incorporated into the substrates disclosed herein), where these magnetic materials may be the same or different. See International Patent Application Publication WO2017 / 195107 by Yang et al., which is also incorporated herein by reference in its entirety.

[0080] Substrate coating process The catalyst composition can be mixed with water to form a slurry (when in dry form) for the purpose of coating the catalyst substrate. In addition to the catalyst particles, the slurry may optionally contain alumina as a binder, an associative thickener, and / or a surfactant (including anionic, cationic, nonionic, or amphoteric surfactants). In some embodiments, the pH of the slurry can be adjusted to an acidic pH, for example, about 3 to about 5. If present, the alumina binder is typically about 0.02 g / in 3 ~Approximately 0.5g / in 3 It is used in this quantity. The alumina binder can be, for example, boehmite, gamma alumina, or delta / theta alumina.

[0081] The slurry can be ground to facilitate particle mixing and form a homogeneous material. Grinding can be carried out using a ball mill, continuous mill, or other similar apparatus, and the solid content of the slurry can be, for example, about 20% to 60% by mass, or for example, about 30% to 40% by mass. In one embodiment, the ground slurry is characterized by a D90 particle size of about 10 microns to about 50 microns (for example, about 10 microns to about 20 microns). D90 is defined as a particle size in which about 90% of the particles have a finer particle size.

[0082] The slurry is then applied onto the catalyst substrate using washcoat techniques known in the art. As used herein, the term “washcoat” has the common meaning in the art of a thin, adhered coating of material applied to a substrate such as a honeycomb flow-through monolith or filter substrate that is sufficiently porous to allow its passage through the gas flow being treated. As used herein and as described in Heck, Ronald and Robert Farrauto, Catalytic Air Pollution Control, New York: Wiley-Interscience, 2002, pp. 18-19, the washcoat layer comprises compositionally different layers of material placed on the surface of a monolithic substrate or on an underlying washcoat layer. The substrate may contain one or more washcoat layers, each washcoat layer may have its own unique chemocatalytic function.

[0083] In some embodiments, the substrate is either immersed in the slurry one or more times, or coated with the slurry. The coated substrate is then dried at a high temperature (e.g., 100-150°C) for a certain period of time (e.g., 1-3 hours), and then fired at a temperature of, for example, 400-600°C, typically for about 10 minutes to about 3 hours. After drying and firing, the final washcoat coating layer can be considered essentially solvent-free.

[0084] After firing, the catalyst load or supported amount can be determined by calculating the difference between the mass of the substrate after coating and the mass before coating. As will be apparent to those skilled in the art, the catalyst supported amount can be changed by altering the slurry rheology. Furthermore, the coating / drying / firing process can be repeated as needed to build up the coating to the desired level of support or thickness.

[0085] The catalyst composition can be applied as a single layer or as multiple layers. A catalyst layer resulting from repeatedly washing and coating the same catalyst material to increase the support level is usually considered a single catalyst layer. In another embodiment, the catalyst composition can be applied in multiple layers, each having a different composition. Furthermore, the catalyst composition can be zoned-coated. This means that different catalyst compositions can be coated in different regions along the gas effluent channel on a single substrate.

[0086] Waste disposal system This disclosure also provides an exhaust treatment system incorporating the catalyst articles described herein (where the substrates include a base material and a magnetic material). The catalyst articles are typically used in an integrated exhaust treatment system with one or more additional components for treating gasoline or diesel exhaust emissions. Thus, terms such as “exhaust flow,” “engine exhaust flow,” and “exhaust gas flow” refer not only to the effluent from the engine but also to the effluent downstream of one or more other catalyst system components described herein.

[0087] The catalyst articles having substrates suitable for induction heating disclosed herein can be positioned at various locations within an exhaust treatment system relative to other components. In some embodiments, the disclosed catalyst articles are directly coupled to the engine. The distance between the engine and the catalyst article can be made considerably short, resulting in a so-called "close-coupled" catalyst configuration. Alternatively, the distance from the engine to the catalyst can be increased to an "underfloor" configuration. The catalyst articles disclosed herein can also be positioned such that one or more other components are present between the engine and the catalyst article. For example, one or more other catalyst articles can be located upstream of the disclosed catalyst article. Similarly, one or more other catalyst articles can be located downstream of the disclosed catalyst article.

[0088] Figure 6 shows an exemplary emissions treatment system. This figure is a schematic diagram of the emissions treatment system 40. As shown, the exhaust gas stream containing gaseous pollutants and particulate matter is transported from the engine 42 through the exhaust pipe 43 to the diesel oxidation catalyst (DOC) 44. In the DOC 44, unburned gaseous hydrocarbons and non-volatile hydrocarbons (i.e., SOF) and carbon monoxide are mostly burned to form carbon dioxide and water. Furthermore, NO x A portion of the NO component is oxidized to NO2 within the DOC. Next, the exhaust flow is transported via the exhaust pipe 45 to a catalytic soot filter (CSF) 46, where particulate matter present in the exhaust gas flow is captured. The CSF 46 is optionally catalytically activated to passively or actively regenerate soot. After the removal of particulate matter by the CSF 46, the exhaust gas flow is transported via the exhaust pipe 47 to a downstream selective catalytic reduction (SCR) component 48, where NO is removed. x Further processing and / or conversion of the material is performed. Note that any or all of the catalyst components described above, or any other catalyst components, may comprise the substrates disclosed herein, which include a magnetic material. Note also that the disclosure is not limited thereto. That is, the principles disclosed herein are also relevant to various different types of catalysts and can be employed in connection with a wide range of catalysts and related waste treatment systems.

[0089] Figure 7 is a schematic diagram of an exemplary catalyst article 50. Arrows 52 and 52' indicate the direction of travel of engine exhaust (52 indicates gas entering the catalyst, and 52' indicates gas leaving the catalyst / processed by the catalyst). As illustrated, the catalyst article 50 includes a catalyst 2 sealed in an exhaust pipe canister 54. In the illustrated embodiment, the catalyst 2 includes the magnetic material described herein. A wire coil 66 surrounds the catalyst 2 to provide an alternating magnetic field 68 suitable for inductive heating of the magnetic material within the substrate, and this wire coil is attached to a power supply 70. It should be noted that the illustrated embodiment is not intended to limit the coil structure. For example, in some embodiments, the coil does not comprise a single coil, but rather comprises two or more individual coils. In some such configurations, the substrate may be surrounded at the front (upstream) end by one coil and at the rear (downstream) end by another coil, optionally with a gap between them.

[0090] Furthermore, it should be noted that the coil 66 depicted is wound axially around the catalyst so that the magnetic field is parallel to the gas flow. However, the disclosed system is not limited thereto. In some embodiments, the coil 66 (or a plurality of coils as described above) can be positioned laterally on the catalyst so that the magnetic field it generates crosses the gas flow.

[0091] The wire coil 66 is electrically connected to a power supply 70 capable of supplying alternating current to the coil, with an output power typically in the range of about 5 kW to 50 kW and a frequency of about 1 kHz to about 1000 kHz (e.g., about 10 kHz to about 500 kHz). Note that the field strength can determine the extent to which the magnetic material in the substrate described herein can be magnetized. Note that the illustrated embodiment is merely an example of the present disclosure. In alternative embodiments, the coil 66 may be located elsewhere, such as surrounding the catalyst canister 54 or other catalytic components of the system. Furthermore, the technology depicted in this figure can be applied to various types of exhaust catalysts and is not limited to any particular type of catalyst, such catalysts include the types of catalysts mentioned herein (e.g., SCR, DOC, SCRoF, AMO).x Other catalysts include, but are not limited to, these.

[0092] The system 50 further includes an optional temperature sensor 72 positioned to measure the temperature of the engine effluent gases entering the catalyst 2. Both the power supply 70 and the temperature sensors 72 and 74 are operably connected to controllers 76 and 78, which are configured to control the power supply 70 and receive temperature signals from the sensors. As will be understood, the controllers 76 and 78 may have hardware and associated software adapted to allow the controllers to instruct the power supply to energize the electric coil 66 whenever induction heating of the magnetic material is desired. The controllers may select the time period for induction heating based on various factors, such as a specific time period based on engine ignition (e.g., a control system adapted to induction heating the magnetic material for a set period following engine ignition) or a specific preset time interval, for example, based on a specific temperature setpoint associated with the temperature sensors 72 and / or 74.

[0093] Figure 8 shows a system 51 similar to system 50, but using one or more catalyst articles to be induction heated. Electric coils 66 and 66' surround catalysts 2 and 2' and provide alternating magnetic fields 68 and 68' adapted to the induction heating of the magnetic material in the substrate. The system optionally includes temperature sensors 72, 72', 74, and 74', which are operably connected to controllers 76, 76', 78, and 78', respectively, configured to control associated power supplies 70 and 70' and to receive temperature signals from the corresponding sensors. Note that in some embodiments, a single temperature controller may be present instead of 74 and 72', in which case its temperature sensor may be attached to both power supplies 70 and 70' and configured to control these power supplies.

[0094] The magnetic materials described in this book can be added to any catalyst substrate where induction heating of the catalyst coating (or multiple coatings) is useful to maintain the catalyst composition within the optimal temperature range for catalytic activity. The desired temperature range varies depending on the type and function of the catalyst, but is typically in the range of about 100°C to 450°C, for example, about 150°C to 350°C. Specific examples include SCR catalysts, which typically need to be heated to at least about 150°C to promote useful SCR activity; DOC catalysts, which typically need to be heated to at least about 120°C for useful CO oxidation; and LNTs, which typically need to be heated to at least about 120°C for useful NO oxidation. x It needs to be heated to at least about 150°C for storage, and useful regeneration / NOx is needed. x It needs to be heated to at least about 250°C for reduction.

[0095] Non-limiting examples of embodiments: Without limiting them, some embodiments of this disclosure include the following:

[0096] 1. A catalyst substrate comprising a) a ceramic material and b) a magnetic material, wherein the magnetic material can be inductively heated in response to an applied alternating magnetic field.

[0097] 2. The catalyst substrate according to Embodiment 1, wherein the magnetic material is contained within the ceramic material.

[0098] 3. The catalyst substrate according to Embodiment 1, wherein the magnetic material is contained within the pores of the ceramic material.

[0099] 4. The catalyst substrate according to any one of Embodiments 1 to 3, wherein the magnetic material includes an electrically insulating material.

[0100] 5. The catalyst substrate according to any one of Embodiments 1 to 4, wherein the magnetic material contains one or more metal oxides.

[0101] 6. The catalyst substrate according to Embodiment 5, wherein the one or more metal oxides are selected from transition metal oxides and rare earth metal oxides.

[0102] 7. The catalyst substrate according to Embodiment 6, wherein the one or more metal oxides include one or more oxides of lanthanum, cerium, neodymium, gadolinium, yttrium, praseodymium, samarium, hafnium, tungsten, manganese, iron, cobalt, nickel, copper, and zinc.

[0103] 8. The catalyst substrate according to any one of Embodiments 1 to 7, wherein the magnetic material is in particulate form.

[0104] 9. The catalyst substrate according to any one of Embodiments 1 to 8, wherein the ceramic material comprises cordierite, silicon carbide, or aluminum titanate.

[0105] 10. The catalyst substrate according to any one of Embodiments 1 to 9, wherein the magnetic material is substantially uniformly distributed throughout the ceramic material.

[0106] 11. The catalyst substrate according to any one of Embodiments 1 to 9, wherein the magnetic material is more concentrated within a specific region of the ceramic material.

[0107] 12. The catalyst substrate according to any one of Embodiments 1 to 9, wherein the catalyst substrate comprises an inlet end and an outlet end, and the magnetic material is concentrated more at the inlet end than at the outlet end, or more at the outlet end than at the inlet end.

[0108] 13. The catalyst substrate according to any one of Embodiments 1 to 9, wherein the catalyst substrate is cylindrical having a radial center and a radial edge, and the magnetic material is concentrated more in the radial center than in the radial edge, or the magnetic material is concentrated more in the radial edge than in the radial center.

[0109] 14. The catalyst substrate according to any one of Embodiments 1 to 13, having an inlet end and an outlet end, and having a plurality of parallel gas channels that are open to the fluid flow and extend from the inlet end to the outlet end.

[0110] 15. A catalyst substrate according to any one of Embodiments 1 to 13, having an inlet end and an outlet end, and having a plurality of parallel gas flow channels extending from the inlet end to the outlet end, wherein a portion of the plurality of parallel gas flow channels is closed at the inlet end and open at the outlet end, and the plurality of parallel gas flow channels alternately open at the inlet end and closed at the outlet end.

[0111] 16. A catalyst article comprising a catalyst wash coat on a catalyst substrate according to any one of Embodiments 1 to 15.

[0112] 17. The catalyst wash coat oxidizes carbon monoxide, hydrocarbons, NO x Oxidation of NO x Reduction of , oxidation of ammonia, NO x Selective contact reduction, NO x A catalyst article according to Embodiment 16, comprising a catalyst material suitable for one or more of the following: storage / reduction, oxygen storage, combustion or oxidation of soot, and water-gas shift.

[0113] 18. Diesel oxidation catalyst (DOC), catalytic soot filter (CSF), lean NO x Traps (LNT), selective catalytic reduction (SCR) catalysts, filtered SCR catalysts (SCRoF), ammonia oxidation (AMO) x ) Catalyst, NO x A catalyst article according to Embodiment 16 or 17, suitable for use as an absorbent or a three-way catalyst (TWC).

[0114] 19. A system comprising a catalyst article according to any one of embodiments 16 to 18, which includes a conductor for receiving an electric current and generating an alternating electromagnetic field in response thereto, wherein the conductor is positioned such that the generated alternating electromagnetic field is applied to at least a portion of a magnetic material.

[0115] 20. The system according to embodiment 19, wherein the conductor is in the form of at least one coil of conductive wire surrounding at least a portion of the catalyst article.

[0116] 21. The system according to embodiment 19, further comprising a power supply electrically connected to the conductor for supplying alternating current to the conductor.

[0117] 22. The system of Embodiment 19, further comprising a temperature sensor positioned to measure the temperature of the gas entering the catalyst article, and a controller communicating with the temperature sensor, wherein the controller is adapted to control the current received by a conductor so that the controller can supply current to the conductor when induction heating of the catalyst substrate is desired.

[0118] 23. A method for treating emissions from an internal combustion engine, wherein exhaust gas generated from the internal combustion engine is treated by an emissions treatment system, the emissions treatment system includes a system described in any one of embodiments 19 to 22.

[0119] 24. The method according to Embodiment 23, wherein the internal combustion engine is a gasoline engine, a diesel engine, a hybrid electric engine, or a natural gas engine. [Examples]

[0120] The aspects of the disclosed subject matter will be further described with reference to specific embodiments. These embodiments are merely representative of the countless possible embodiments that fall within the scope of this disclosure and should not be construed as limiting this disclosure.

[0121] Example 1: Activation of flow-through substrate In a typical preparation, 173 g of nickel-zinc ferrite powder was combined with 248 g of pure water. Next, 21 g of dispersible aluminum oxide was added, and the resulting suspension was mixed and homogenized under high shear conditions. Finally, 33 g of a 30% zirconium oxide solution dissolved in acetic acid was added to the suspension, and the pH was adjusted to 6.5 with monoethanolamine. This suspension was ground in a ceramic ball mill until the particle size distribution showed a D90 of approximately 11 mm. A porous ceramic honeycomb flow-through substrate with dimensions of 10.1 mm × 10.1 mm × 76 mm, flow path density = 300 cpsi, and wall thickness of 8 mils, with a square-to-prismatic shape, was immersed in this slurry until the component was saturated. The component was removed from the slurry, and the excess slurry was drained. The remaining slurry was spread throughout the component using an air jet. The resulting moist ceramic piece was dried with an airflow at 120°C, and then fired in air at 550°C for 1 hour. The nominal load of nickel-zinc ferrite on the component obtained by this procedure is 1.0 g / in. 3 This was the volume of the base material. This immersion, drying, and firing procedure was repeated for five different base material components.

[0122] Figure 9A is a low-magnification SEM image of a cross-section of the obtained activated substrate viewed along the channel axis. The gray areas represent the ceramic substrate, and the bright areas indicate the location of nickel-zinc ferrite. The low-magnification image shows that at least some of the nickel-zinc ferrite is present on the surface of the porous substrate, particularly at the corners of the channels. Figure 9B is a high-magnification SEM image of the activated substrate, viewed along the channel axis. This image shows that a significant proportion of the nickel-zinc ferrite has penetrated into the internal voids of the channel walls.

[0123] Example 2: Activation of filter substrate The ceramic substrate was activated in "filter mode" using the slurry prepared in Example 1. Specifically, the channels at the inlet end of the ceramic substrate were alternately blocked with ceramic paste. The remaining, fully open channels were blocked with ceramic paste at the outlet end. In this configuration, the only flow path from one end of the substrate to the other passes through the pores in the channel walls. This type of ceramic honeycomb substrate, with dimensions of 10.1 mm × 10.1 mm × 114 mm, a flow path density of 300 cpsi, and a wall thickness of 8 mils, had a square-prism shape and was immersed in the slurry until saturated. The component was removed from the slurry, and the excess slurry was drained. The remaining slurry was then spread throughout the component using an air jet. The resulting wet ceramic piece was dried with an airflow at 120°C and then fired in air at 550°C for 1 hour. The nominal loading of nickel-zinc ferrite on the component obtained by this procedure was 1.0 g / in. 3 The volume of the base material was determined. This immersion, drying, and firing procedure was repeated for five different base material components.

[0124] Figure 10A is a low-magnification SEM image of a cross-section of the obtained activated substrate viewed along the channel axis. The gray areas represent the ceramic substrate, and the bright areas indicate the location of nickel-zinc ferrite. The low-magnification image shows that at least some of the nickel-zinc ferrite is present on the surface of the porous substrate, particularly in the inlet channel of the filter substrate. Figure 10B is a high-magnification SEM image of the activated substrate, viewed along the channel axis. This image shows that a significant proportion of the nickel-zinc ferrite has also penetrated into the internal voids of the channel wall.

[0125] Evaluation of activated ceramic substrates for magnetic induction heating Samples were selected from each set of activated substrates prepared in Examples 1 and 2 and cut to a length of 25 mm. The 25 mm segments were wrapped in flexible ceramic tape to form a mat and inserted into a glass tube with an outer diameter of 25 mm. This glass tube assembly was mounted inside a 10-gauge core wire with an outer diameter of 33 mm. The coil was 44 mm long and had a wire that was wound seven times. An AC potential of 26 V (peak) oscillating at 53 kHz was applied using an AC power supply designed for induction heating coils. The ceramic sample was placed in the center along the axis of the coil. Two thin K-type thermocouples were inserted into the substrate channel at positions indicated as TC1 and TC2 in the inset of Figure 11. The thermocouples were positioned in the center along the longitudinal direction of the channel. When the AC potential was applied to the coil, the temperature at TC1 and TC2 increased over time, as shown in Figure 11. From this data, it can be seen that the rate of temperature rise is substantially the same for substrates coated by the flow-through method and the filter method. The thermocouple placed at the edge of the component (TC2) shows a slightly lower temperature than the center (TC1), but the entire surface of the component appears to be heated fairly uniformly. This is even clearer in the series of infrared thermal images in Figure 12, which were collected every 30 seconds during the evaluation of Example 2. These images show that the component was heated uniformly across the cross-section of the sample for two minutes. In the case of the control sample, which consisted of a substrate not activated with nickel-zinc ferrite, no temperature rise was observed at any of the TC positions. This indicates that a magnetic material is functionally necessary to achieve heating by magnetic induction.

[0126] The uniformity of heating achieved in Examples 1 and 2 is understood to be a result of the fact that the active magnetic particles are distributed throughout the ceramic component, and each particle is heated independently. The physical mechanism by which the magnetic particles are heated is based on magnetic hysteresis loss and is fundamentally different from the classical induction heating of conductive materials. To demonstrate this difference, a cylindrical metal substrate with an outer diameter of 24 mm was attached to an induction coil. When the same AC potential used for the ceramic component above was applied, an extremely non-uniform heat distribution was obtained, as shown in the thermal image in Figure 13. Similarly, only the outer edge of the metal substrate was heated. The center of the component could only be heated by heat conduction from the outer periphery. This is a manifestation of the electrical "skin effect," which is well known in the design of AC circuits. This reflects the fact that heat is generated by eddy currents induced in a conductive component, but these eddy currents are strongly localized on the outer periphery of the conductor.

[0127] While the subject matter disclosed herein has been illustrated by specific embodiments and their applications, numerous modifications and variations can be made by those skilled in the art without departing from the scope of disclosure set forth in the claims. Furthermore, various aspects of this disclosure can be used for purposes other than those specifically described herein.

Claims

1. A catalyst substrate, a) Ceramic materials and, b) Magnetic material Equipped with, The magnetic material is capable of induction heating in response to an applied alternating magnetic field. The magnetic material comprises one or more metal oxides, and the one or more metal oxides comprises one or more of the oxides of lanthanum, cerium, neodymium, gadolinium, yttrium, praseodymium, samarium, hafnium, tungsten, manganese, iron, cobalt, nickel, copper, and zinc. The magnetic material has an average particle size of 1 nm to 500 nm. The magnetic material is contained within the pores of the ceramic material, or the magnetic material is contained within the ceramic material. A catalyst substrate characterized by the following features.

2. The catalyst substrate according to claim 1, wherein the magnetic material includes an electrically insulating material.

3. The catalyst substrate according to any one of claims 1 to 2, wherein the magnetic material is in particulate form.

4. The catalyst substrate according to any one of claims 1 to 3, wherein the ceramic material comprises one or more of cordierite, silicon carbide, or aluminum titanate.

5. The catalyst substrate according to any one of claims 1 to 4, wherein the magnetic material is uniformly distributed throughout the ceramic material.

6. The catalyst substrate according to any one of claims 1 to 5, wherein the catalyst substrate is in the form of a monolithic flow-through substrate having an inlet end and an outlet end, and has a plurality of parallel gas channels extending from the inlet end to the outlet end, which are open to the fluid flow.

7. The catalyst substrate according to any one of claims 1 to 5, wherein the catalyst substrate is in the form of a wall-flow substrate having an inlet end and an outlet end, and a plurality of parallel gas channels extending from the inlet end to the outlet end, a portion of the plurality of parallel gas channels being closed at the inlet end and open at the outlet end, and the plurality of parallel gas channels being open at the inlet end of alternating portions and closed at the outlet end.

8. A catalyst article characterized by having a catalyst wash coat provided on a catalyst substrate according to any one of claims 1 to 7.

9. The catalyst wash coat oxidizes carbon monoxide, hydrocarbons, and NO ｘ Oxidation of NO ｘ Reduction of , oxidation of ammonia, NO ｘ Selective catalytic reduction of NO ｘ The catalyst article according to claim 8, comprising a catalyst material suitable for one or more of the following: storage / reduction of oxygen, oxygen storage, combustion or oxidation of soot, and water-gas shift.

10. The catalyst substrate comprises a diesel oxidation catalyst (DOC), a catalytic soot filter (CSF), and lean NO. ｘ Trap (LNT), selective catalytic reduction (SCR) catalyst, filtered SCR catalyst (SCRoF), ammonia oxidation (AMO) ｘ ) Catalyst, NO ｘ A catalyst article according to claim 8 or 9, which is adapted for use as an absorber or a three-way catalyst (TWC).

11. A catalyst article according to any one of claims 8 to 10, and A conductor that receives an electric current and generates an alternating current electromagnetic field in response. Equipped with, A system characterized in that the conductor is arranged such that the generated AC electromagnetic field is applied to at least a portion of the magnetic material.

12. The system according to claim 11, wherein the conductor is in the form of at least one coil of conductive wire surrounding at least a portion of the catalyst article.

13. The system according to claim 11, further comprising a power supply electrically connected to the conductor for supplying alternating current to the conductor.

14. The system according to claim 11, further comprising a temperature sensor positioned to measure the temperature of the gas entering the catalyst article, and a controller that communicates with the temperature sensor, wherein the controller controls the current received by the conductor and supplies current to the conductor when induction heating of the catalyst substrate is desired.

15. A method for treating emissions from an internal combustion engine, comprising treating exhaust gas generated from the internal combustion engine with an emissions treatment system, wherein the emissions system comprises the system described in any one of claims 11 to 14.

16. The method according to claim 15, wherein the internal combustion engine is a gasoline engine, a diesel engine, a hybrid electric engine, or a natural gas engine.

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