Induction heating type NOx adsorbent

Abstract

The present application provides articles, systems, and methods for adsorbing and desorbing nitrogen oxides (NOx) at desired temperatures. The catalytic articles include NOx catalysts containing platinum group metal (PGM) components disposed on or impregnated in a support material. x The catalytic article comprises an adsorbent composition and a substrate, and further comprises a magnetic material capable of being inductively heated in response to an applied alternating electromagnetic field. The catalytic article further comprises a conductor associated therewith for receiving an electric current and generating an alternating electromagnetic field in response thereto, the conductor being positioned such that the generated alternating electromagnetic field is applied to at least a portion of the magnetic material. The field inductively heats the magnetic material to produce NO. x The sorbent composition is heated and the NO x Adsorbent composition from NO x can be released.

Description

Technical Field

[0001] This application claims the benefit of priority of U.S. Provisional Application No. 63 / 087,680, filed on October 5, 2020, the content of which is hereby incorporated by reference in its entirety.

[0002] The present disclosure relates to compositions for use in treating engine effluent, methods for the manufacture and use of such compositions, and catalyst articles and systems employing such compositions.

Background Art

[0003] Diesel engine effluent contains particulate matter (PM), nitrogen oxides (NOx), unburned hydrocarbons (HC), carbon monoxide (CO), etc. NOx is a term representing various chemical species of nitrogen oxides such as nitric oxide (NO) and nitrogen dioxide (NO2). Two main components of exhaust particulate matter are the soluble organic fraction (SOF) and the soot fraction. SOF condenses in layers on top of the soot and generally originates from unburned diesel fuel and lubricating oil. SOF exists in diesel exhaust as a vapor or as an 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 the exhaust gas varies depending on the type of engine and operating parameters but usually includes various short-chain hydrocarbons such as methane, ethane, propane, and long-chain fuel-based hydrocarbons.

[0004] To treat NOx-containing gas mixtures to reduce air pollution, various treatment methods have been used. Catalysts used to treat the exhaust of internal combustion engines are less effective during relatively low-temperature operating periods such as the initial cold start period of engine operation because the temperature of the engine exhaust is not high enough for efficient catalytic conversion. For example, this occurs for downstream catalyst components, particularly those placed after high-thermal-mass filters such as SCR catalysts, and it can take several minutes to reach the appropriate 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 one example, 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] Recently, induction heating of the catalyst body has been investigated (see, for example, U.S. Patents 9,488,085, 10,132,221, and 10,352,214 by Crawford and Douglas). Current technology uses conductive elements embedded in a ceramic substrate, which are heated by inducing eddy currents in the conductor. Non-contact induction heating of catalysts has several advantages: it does not require direct electrical connection to the catalyst body, and it incorporates a ceramic support for the catalyst washcoat. However, current technology suffers from the complexity of manufacturing (such as the fusion of ceramic / metal interfaces) and the uneven distribution of heat. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] U.S. Patent No. 8,479,496 [Patent Document 2] Strength No. 10,690,031 [Patent Document 3] U.S. Patent No. 6,112,519 [Patent Document 4] U.S. Patent No. 8,156,737 [Patent Document 5] U.S. Patent Application Publication US2011 / 0072805 [Patent Document 6] US Patent No. 10,677,127 [Patent Document 7] U.S. Patent No. 10,731,534 [Patent Document 8] U.S. Patent No. 10,681,779 [Patent Document 9] U.S. Patent No. 9,845,714 [Patent Document 10] U.S. Patent No. 8,784,741 [Patent Document 11] U.S. Patent No. 8,329,110 [Patent Document 12] U.S. Patent No. 10,138,781 [Patent Document 13] U.S. Patent No. 10,082,047 [Patent Document 14] U.S. Patent No. 9,506,426 [Patent Document 15] U.S. Patent No. 10,273,906 [Patent Document 16] U.S. Patent No. 6,657,315 [Patent Document 17] U.S. Patent No. 8,955,473 [Patent Document 18] U.S. Patent No. 9,382,857 [Patent Document 19] U.S. Patent No. 9,488,085 [Patent Document 20] U.S. Patent No. 10,132,221 [Patent Document 21] U.S. Patent No. 10,352,214 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] In this field, there remains a need to reduce tailpipe emissions of gaseous pollutants from gasoline or diesel engines, particularly breakthrough emissions (e.g., NOx) that occur during cold engine starts. [Means for solving the problem]

[0009] This disclosure provides catalyst articles, systems, and related methods adapted to facilitate the induction heating of catalyst materials. In some embodiments, this disclosure covers catalyst articles that, under specified conditions, capture (adsorb) and desorb nitrogen oxides (NOx) therefrom, thereby providing control over adsorption and / or desorption from the catalyst article. Such catalyst articles can, for example, capture NOx at low temperatures and retain the captured NOx until a specified event is reached (for example, until a certain temperature is reached, such as the temperature at which a downstream SCR catalyst is understood to be activated). In this way, it is possible to avoid large amounts of NOx passing through a downstream SCR that is not at a temperature sufficient to promote NOx reduction.

[0010] In some embodiments, the present disclosure provides a method for adsorbing and desorbing nitrogen oxides (NOx) from a catalytic article for treating exhaust gas flow from a diesel engine or lean-burn gasoline engine, comprising: contacting the exhaust gas flow with a catalytic article, the catalytic article comprising a NOx adsorbent composition comprising platinum group metal (PGM) components arranged on or impregnated into a carrier material, and a substrate, wherein the NOx adsorbent composition is effective for storing NOx at temperatures below 225°C, and wherein the catalytic article is subjected to applied pressure. The present invention provides a magnetic material that can be inductively heated in response to an electromagnetic field, wherein the catalyst article further comprises a conductor associated therewith to receive an electric current and generate an alternating electromagnetic field in response thereto, the conductor being arranged such that the generated alternating electromagnetic field is applied to at least a portion of the magnetic material; and a method is provided comprising generating an alternating electromagnetic field by intermittently exciting the conductor by passing an electric current through it, inductively heating the magnetic material to heat a NOx adsorbent composition to a temperature above 225°C, and desorbing NOx from the NOx adsorbent composition.

[0011] In some embodiments, the conductor is adapted to feedback control, and intermittent excitation is performed only when the substrate temperature is below 225°C. In some embodiments, intermittent excitation is performed on demand.

[0012] In some embodiments, the disclosed method further includes contacting an exhaust gas flow with a selective catalytic reduction (SCR) catalyst composition downstream of a NOx adsorbent composition. In some embodiments, the NOx adsorbent composition and the SCR catalyst composition are, for example, on the same substrate or they are on separate substrates. In some embodiments, the disclosed method further includes monitoring the temperature of the SCR catalyst composition, in which case intermittent excitation occurs when the temperature of the SCR catalyst composition rises above a predetermined temperature. In some embodiments, this predetermined temperature varies. In some embodiments, the predetermined temperature is about 180°C, and in some embodiments, the predetermined temperature is about 200°C.

[0013] In some embodiments, the method further includes maintaining the NOx adsorbent composition at a temperature higher than 225°C, where the SCR catalyst composition is at a predetermined temperature. In some embodiments, the method further includes removing the current when the SCR catalyst composition falls below a predetermined temperature.

[0014] In some embodiments, the present disclosure provides a system for processing exhaust gas streams from a diesel engine or a lean-burn gasoline engine. The system comprises a catalyst article comprising a NOx adsorbent composition in which platinum group metal (PGM) components are disposed on or impregnated into a carrier material, wherein the NOx adsorbent composition is effective for storing NOx at a temperature below 225°C, and the catalyst article comprises a magnetic material that can be inductively heated in response to an applied alternating electromagnetic field; a conductor for receiving an electric current and generating an alternating electromagnetic field in response thereto, the conductor being arranged so that the generated alternating electromagnetic field is applied to at least a portion of the magnetic material; and an SCR catalyst composition downstream of the NOx adsorbent composition.

[0015] 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 two, three, four, or more features or elements provided in this disclosure, regardless of whether such features or elements are expressly combined in the description of a particular embodiment herein. This disclosure is intended to be read holistically, and unless explicitly indicated in that context, any separable features or elements of the disclosed subject matter should be considered to be 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]

[0016] The accompanying drawings are provided for reference to aid in understanding the embodiments of this disclosure. However, the accompanying drawings are not necessarily drawn to an exact scale. Reference numerals indicate components of exemplary embodiments of the disclosed subject matter. The drawings are illustrative and should not be construed as limiting the disclosure. [Figure 1] Figure 1 is a perspective view of a honeycomb-type substrate that may contain the catalyst composition described herein. [Figure 2] Figure 2 is an enlarged version of Figure 1, showing a partial cross-sectional view cut along a plane parallel to the end face of the carrier in Figure 1, and illustrating an enlarged view of the multiple gas flow channels shown in Figure 1. [Figure 3] Figure 3A is a partial cross-sectional view of the catalyst substrate perpendicular to the channel direction, showing the channel opening 10, the substrate wall 12, and the magnetic particles 20 dispersed on the wall.

[0017] Figure 3B 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 magnetic particles 20 dispersed in the pores of the substrate material. [Figure 4]Figure 4 is a schematic diagram of one embodiment of a catalyst article functionalized to enable induction heating as disclosed herein. [Figure 5] Figure 5 is a schematic diagram showing one embodiment of an exhaust treatment system employing the catalyst article disclosed herein. [Modes for carrying out the invention]

[0018] The present disclosure will now be described in more detail. While the subject matter of this specification 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 present disclosure without departing from the spirit and scope of the present disclosure. Accordingly, the subject matter 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 subject matter are possible and can be carried out 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.

[0019] This disclosure provides catalysts, systems, and related methods that generally encompass the control of adsorption and / or desorption of nitrogen oxides (NOx) from a catalyst article. For example, the adsorption and / or desorption of NOx is controlled by intentionally altering the temperature of the catalyst article, particularly the temperature of the catalyst composition in the form of a wash coat attached to a substrate. The temperature control referred to herein can be achieved, for example, by employing a catalyst article that responds to the application of an electric current, where the current can be actuated to effectively induce heating of the wash coat (catalyst composition) of the catalyst article when NOx desorption is desired (e.g., when a downstream selective catalytic reduction (SCR) catalyst has reached a temperature sufficient for appropriate activity).

[0020] Catalyst articles generally need to contain at least one component that responds to an applied electric current so that the composition can be characterized as "heatable" (e.g., inductively heatable) when an electric current is applied. To realize such a possibility, catalyst compositions may, in some embodiments, include a mixture of catalytically active particles and a magnetic material that can be inductively heated in response to an applied alternating electromagnetic field. Specific components that can be employed in catalyst compositions to perform this function include, but are not limited to, those described in BASF International Patent Application Publication W02017 / 195107, which is incorporated herein by reference in its entirety. Alternatively, catalyst articles may include a magnetic material in the substrate. This is described, for example, in U.S. Provisional Application, Caudle et al., Application No. 63 / 087,640, filed October 5, 2020, which is incorporated herein by reference in its entirety.

[0021] The use of induction heating of a magnetic material associated with a catalyst article can be an efficient means of transferring heat to the catalyst composition of the catalyst article. The “magnetic material” is selected from ferromagnetic materials, ferrimagnetic materials, and paramagnetic materials. The form of the magnetic material associated with the catalyst article according to this disclosure is selected from particulate forms, such as nanoparticle magnetic materials shown as superparamagnetic materials, or from nanowires, nanotubes, sheets, or other forms.

[0022] 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 consider 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 of 5, whether explicitly indicated or not, are modified by the term "about." Numbers modified by the term "about" include the value specified therein. For example, "about 5.0" includes 5.0.

[0023] "Reduction" means a decrease in quantity, caused by any means.

[0024] "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.

[0025] The term “associated” means, for example, “equipped,” “connected,” or “communicated,” for example, “electrically connected,” or “fluidly connected,” or otherwise connected in order to perform a function. The term “associated” may also mean directly or indirectly related, for example, through one or more other articles or elements.

[0026] "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).

[0027] 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.

[0028] In this disclosure, the term "catalyst article" means an article comprising a substrate having a catalyst coating composition.

[0029] 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.”

[0030] "CSF" refers to a wall-flow monolithic catalytic soot filter. A wall-flow filter consists of alternating inlet and outlet channels, with the inlet channels blocked at the outlet end and the outlet channels 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.

[0031] "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.

[0032] As used in this book, the term "waste treatment system" refers to a combination of two or more catalyst components, for example, a combination of LNT-LT-NA disclosed herein and one or more additional catalyst components (which may be, for example, CSF, DOC, or selective catalytic reduction (SCR) catalyst articles).

[0033] 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%, 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%.

[0034] 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. 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 (region) 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.

[0035] 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."

[0036] In this disclosure, the term "functional article" means an article comprising a substrate having a functional coating composition, particularly a catalyst and / or adsorbent coating composition, disposed thereon.

[0037] As used in this book, "impregnation" or "penetration" means that the catalyst material penetrates the porous structure of the support material.

[0038] The terms “on” and “over” in relation to coating layers can be used as synonyms. The term “directly on” means in direct contact. In one embodiment, the disclosed article is referred to as having one coating layer “on” a second coating layer, but such expression is 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”).

[0039] In this book, the term "promoter" 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.

[0040] 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.

[0041] When used in this book, the term "nitrogen oxides" or "NO x "NO" refers to nitrogen oxides such as NO, NO2, or N2O.

[0042] 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.

[0043] "Substantially absent" means, for example, "almost none or none at all" or "not intentionally added," and means present in trace and / or accidental amounts. For example, in a particular embodiment, "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.

[0044] As used herein, the term “substrate” means a monolithic material on which a catalyst composition, i.e., a catalyst coating, is arranged, typically in the form of a wash coat. In one or more embodiments, the substrate includes flow-through monoliths and monolithic wall-flow filters. 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. “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.

[0045] 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.

[0046] 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 is sufficiently porous 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.

[0047] As used herein, "mass percentage" refers to the entire composition excluding volatiles, i.e., based on the dry solids content, unless otherwise specified. Unless otherwise noted, parts and percentages are all on a mass basis.

[0048] 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.

[0049] Examples of non-limiting embodiments Without limiting them, some embodiments of this disclosure include the following:

[0050] 1. A method for adsorbing and desorbing (or releasing) nitrogen oxides (NOx) from a catalytic article suitable for treating exhaust gas flow from a diesel engine or lean-burn gasoline engine, comprising: namely, The exhaust gas flow is brought into contact with a catalyst article, the catalyst article comprising a platinum group metal (PGM) component which contains a NOx adsorbent composition at a temperature of less than 225°C and is arranged on or impregnated into a carrier material, and a substrate, wherein the NOx adsorbent composition is effective for storing NOx at a temperature of less than 225°C, and Here, the catalyst article includes a magnetic material that can be inductively heated in response to an applied alternating electromagnetic field. Here, the catalyst article has a conductor associated with it to receive an electric current and generate an alternating electromagnetic field in response, the conductor being arranged such that the generated alternating electromagnetic field is applied to at least a portion of the magnetic material; NO x The adsorbent composition is heated to a temperature exceeding 225°C to remove NOx from the NOx adsorbent composition. x To deactivate it, an alternating current is passed through a conductor to intermittently excite it, generating an alternating current electromagnetic field and inductively heating the magnetic material. A method that includes this.

[0051] 2. The method according to Embodiment 1, wherein the conductor is suitable for feedback control and intermittent excitation is performed only when the substrate is at a temperature of less than 225°C.

[0052] 3. The method according to Embodiment 1, further comprising contacting the exhaust gas flow with a selective catalytic reduction (SCR) catalyst composition downstream of the NOx adsorbent composition.

[0053] 4. The method according to Embodiment 3, wherein the NOx adsorbent composition and the SCR catalyst composition are on the same substrate.

[0054] 5. NO x The method according to Embodiment 3, wherein the adsorbent composition and the SCR catalyst composition are located on separate substrates.

[0055] 6. The method according to any one of Embodiments 3 to 5, further comprising monitoring the temperature of the SCR catalyst composition and causing intermittent excitation when the temperature of the SCR catalyst composition rises above a predetermined temperature.

[0056] 7. The method according to Embodiment 6, wherein the predetermined temperature is about 180 °C or about 200 °C.

[0057] 8. The method according to any one of Embodiments 6 to 7, further comprising maintaining the NOx adsorbent composition at a temperature higher than 225 °C as long as the SCR catalyst composition exceeds a predetermined temperature.

[0058] 9. The method according to Embodiment 8, further comprising removing current when the SCR catalyst composition is below a predetermined temperature.

[0059] 10. A system for treating an exhaust gas stream from a diesel engine or a lean burn gasoline engine, comprising: A catalyst article comprising a NOx adsorbent composition at a temperature below 225 °C and a substrate, wherein the NOx adsorbent composition is formed by disposing or impregnating a platinum group metal (PGM) component on a carrier material, and the NO x adsorbent composition is effective for storing NOx at a temperature below 225 °C; where the catalyst article comprises a magnetic material capable of inductive heating in response to an applied alternating electromagnetic field; A conductor for receiving current and generating an alternating electromagnetic field in response thereto, the generated alternating electromagnetic field being arranged to be applied to at least a part of the magnetic material; NO x An SCR catalyst composition downstream of the adsorbent composition; and a system comprising the same.

[0060] 11. The system according to Embodiment 10, wherein the NCR adsorbent composition and the SCR catalyst composition are on the same substrate.

[0061] 12. The system according to Embodiment 11, wherein the NCR adsorbent composition and the SCR catalyst composition are located on separate substrates.

[0062] magnetic component In some embodiments, the size of the magnetic material (e.g., 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 particles can be formed of 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, materials 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.

[0063] 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, it may be advantageous to ensure an average particle diameter of about 25 nm or larger.

[0064] 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 certain embodiments, the magnetic material includes nanoparticle magnetic materials, which are referred to as superparamagnetic materials. However, in certain 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.

[0065] Any material capable of induction heating in the presence of an alternating electromagnetic field can be used, but advantageous magnetic materials include materials containing transition metals or rare earth metals, particularly 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. Oxide forms of many magnetic metals are particularly advantageous for use in this disclosure because metal oxides tend to be very stable at operating temperatures often associated with catalytic systems used to treat emissions from engines. In certain embodiments, the magnetic material associated with the catalyst article comprises superparamagnetic iron oxide nanoparticles (SPION particles) or rare earth-containing particulate materials including neodymium-iron-boron or samarium-cobalt particles. In some embodiments, the magnetic material comprises SPION particles (e.g., iron(III) oxide particles) having an average particle size of less than 100 nm, such as about 5 nm to about 50 nm or about 10 nm to about 40 nm.

[0066] Magnetic materials can be associated with catalyst articles in various ways. For example, association can be made by mixing them with a catalyst material before coating a substrate to obtain a catalyst composition containing the magnetic material (for example, according to the method outlined in BASF International Patent Application Publication W02017 / 195107, which is incorporated herein by reference in its entirety), or by combining the magnetic material with a base material to form a substrate (for example, according to the method outlined in Caudle et al. U.S. Provisional Patent Application 63 / 087,640 (filed October 5, 2020), which is incorporated herein by reference in its entirety).

[0067] Catalyst composition - NOx adsorbent composition With respect to the catalyst material of a catalyst article adapted to induction heating disclosed herein, the material generally comprises at least one component (hereinafter referred to herein as the "NOx adsorbent composition") which can adsorb NOx at a first temperature and desorb NOx at a second temperature (also generally referred to as a low-temperature NOx adsorbent (LT-NA) composition or "passive NOx adsorbent"). Such components are typically effective in storing NOx at temperatures below 200°C and releasing the stored NOx at higher temperatures. For the purposes of this disclosure, the NOx adsorbent is suitable for adsorbing / storing NOx until the downstream SCR catalyst reaches a temperature sufficient to effectively convert the NOx. At such a time (as will be described more fully herein below), an electric current is passed through the catalyst article comprising the NOx adsorbent composition to release NOx. x Adsorbent composition NO x It can be heated to a temperature suitable for the release of (this NO x (Then it can be effectively treated by a downstream SCR catalyst). For example, in some embodiments, NO x The adsorbent composition releases NO at temperatures below approximately 180°C. x Store (and NO at temperatures exceeding approximately 180°C) x (It releases NO) at temperatures below approximately 190°C. x Store (and NO at temperatures exceeding approximately 190°C) x (It releases NO) and at temperatures below approximately 200°C xStore (and NO at temperatures exceeding approximately 200°C) x (It releases NO) at temperatures below approximately 210°C. x Store (and NO at temperatures above approximately 210°C) x (emitting NOx), or storing NOx at temperatures below approximately 225°C (and storing NOx at temperatures above approximately 225°C) x It is designed to release (a substance).

[0068] In some embodiments, NO x Adsorbent composition, NO x Store NO x It is designed to release NO on demand. For example, in some embodiments (e.g., during post-cold start conditions), the LT-NA catalyst releases NO again up to a certain level. x It may be filled with this additional NO by turning on on-demand deactivation. x The NO can be purged outside the catalyst. In one embodiment, this operation can be performed to purge the NO of the LT-NA catalyst. x Adjust the fill level to ensure sufficient NOx for the next cold start. x This can be used as a means to secure capacity.

[0069] Several types of NO x Adsorbents are known, NO x Adsorbent compositions generally comprise molecular sieves made of platinum group metal (PGM) components.

[0070] As used herein, the term “molecular sieve,” including zeolites and other zeolite-framed materials (e.g., isomorphic substitution materials), generally refers to materials based on a broad three-dimensional network of oxygen anions bonded to metal atoms (such as Si and Al) at tetrahedral sites, having a substantially uniform pore distribution with an average pore size not greater than 20 angstroms (Å).

[0071] Molecular sieves can be distinguished primarily by the shape of the voids formed by a rigid network of (SiO4) / A1O4 tetrahedra. The void entrances are surrounded by rings consisting of 6, 8, 10, 12, or 14 oxygen atoms that make up the 6, 8, 10, 12, or 14 (SiO4) / A1O4 tetrahedra that form the entrance openings. Molecular sieves are crystalline materials with rather uniform pore sizes, ranging in diameter from approximately 3 to 10 Å, depending on the type of molecular sieve and the type and amount of cations contained in the molecular sieve lattice. An "8-ring" molecular sieve is a molecular sieve that has 8-ring pore openings and double 6-ring secondary structural units, and has a cage-like structure resulting from the linkage of the double 6-ring structural units by four rings. Molecular sieves include small-pore, medium-pore, and large-pore molecular sieves or combinations thereof. Pore size is defined by the size of the rings.

[0072] Pore ​​molecular sieves contain channels defined by up to eight tetrahedral atoms. As used herein, the term “pore” refers to pore openings smaller than about 5 angstroms, e.g., on the order of -3.8 angstroms. Exemplary pore molecular sieves include skeletal structures ACO, AEI, AEN, AFN, AFT, AFX, ANA, APC, APD, ATT, CDO, CHA, DDR, DFT, EAB, EDI, EPI, ERI, GIS.GOO, IHW, ITE, ITW, LEV, KFI, MER, MON, NSI, OWE, PAU, PHI, RHO, RTH, SAT, SAV, SIV, THO, TSC, UEI, UFI, VNI, YUG, ZON, and mixtures or intergrowths thereof.

[0073] Pore ​​molecular sieves have channels defined by 10-membered rings. Exemplary porous molecular sieves include skeletal structure types AEL, AFO, AHT, BOF, BOZ, CGF, CGS, CHI, DAC, EUO, FER, HEU, IMF, ITH, ITR, JRY, JSR, JST, LAU, LOV, MEL, MFI, MFS, MRE, MTT, MVY, MWW, NAB, NAT, NES, OBW, PAR, PCR, PON, PUN, RRO, RSN, SFF, SPG, STF, STI, STT, STW, SVR, SZR, TER, TON, TUN, UOS, VSV, WEI, WEN, and mixtures or intercrystals thereof.

[0074] Large-pore molecular sieves have channels defined by 12-membered rings. Exemplary large-pore molecular sieves include skeletal structures AFI, AFR, AFS, AFY, ASV, ATO, ATS, BEA, BEC, BOG, BPH, BSV, CAN, CON, CZP, DFO, EMT, EON, EZT, FAU, GME, GON, IFR, ISV, ITG, IWR, IWS, IWV, IWW, JSR, LTF, LTL4, MAZ, MEI, MOR, MOZ, MSE, MTW, NPO, OFF, OKO, OSI, RON, RWY, SAF, SAO, SBE, SBS, SBT, SEW, SFE, SFO, SFS, SFW, SOF, SOS, STO, SSF, SSY, USI, UWY, VET, and mixtures or intercrystals thereof.

[0075] Typically, for example, ABW, ACO, AEI, AEL, AEN, AET, AFI, AFN, AFO, AFR, AFS, AFT, AFX, AFY, AHT, APC, APD, ASV, AT N, ATO, ATS, ATT, ATV, AVL, AWO, AWW, BCT, BEA, BEC, BIK, BOG, BPH, BRE, CAN, CAS, SCO, CFI, SGF, CGS, CH A, CHI, CLO, CON, CZP, DAC, DDR, DFO, DFT, DON, EAB, EDI, EEI, EMT, EON, EPI, ERI, ESV, ETR, EUO, FAU, FE R, GIS, GME, GON, GOO, HEU, IFR, IFY, IHW, IRN, ISV, ITE, ITH, ITW, IWR, IWW, JBW, KFI, LAU, LEV, LOV, LT Any molecular sieve with a skeletal structure, such as A, LTL, LTN, MAZ, MEI, MEL, MER, MFI, MFS, MON, MOR, MOZ, MTF, MTT, MTW, MWF, MWW, NAB, NAT, NES, NPO, NPT, NSI, OBW, OFF, OSI, OSO, OWE, PAR, PAU, PHI, PON, RHO, RON, RRO, RSN, RTE, RTH, RWR, RWY, SAO, SAS, SAT, SAV, SBE, SBS, SBT, SFE, SFF, SFG, SFH, SFN, SFO, SFW, SOS, SSY, STF, STI, STT, TER, THO, TON, TSC, UEI, UFI, USI, UTL, VET, VFI, VNI, VSV, WIE, WEN, YUG, ZON, or combinations thereof, can be used. For example, in certain embodiments, the molecular sieve may include a skeletal structure type selected from the group consisting of CHA (chabazite), FER (ferrielite), and LEV (levyin).

[0076] As used herein, the term “zeolite” refers to specific examples of molecular sieves containing silicon and aluminum atoms. Generally, a zeolite is defined as an aluminosilicate having an open three-dimensional framework structure composed of TO4 tetrahedra sharing corners (where T is A1 or Si, or optionally P). Cationic cations that balance the charge of the anionic framework are loosely bonded to oxygen in the framework, and the remaining pore volume is filled with water molecules. Non-skeletal cations are generally replaceable, and water molecules are removable. Aluminosilicate zeolite structures do not contain phosphorus or other metals isomorphically substituted within the framework. That is, “aluminosilicate zeolite” excludes aluminophosphate materials such as SAPO, A1PO, and MeAlPO materials, while the broader term “zeolite” includes aluminosilicates and aluminophosphates. For the purposes of this disclosure, SAPO, A1PO, and MeAlPO materials are considered non-zeolite molecular sieves.

[0077] Zeolites may comprise SiO4 / A1O4 tetrahedra linked by common oxygen atoms to form a three-dimensional network. The silica-to-alumina molar ratio ("SAR") of the zeolite of the present invention can vary over a wide range, but is generally 2 or greater. For example, the zeolite of the present invention may have an SAR of about 5 to about 1000, for example, about 10 to about 100 or about 10 to about 50 or about 15 to about 30.

[0078] NO xThe molecular sieve of the adsorbent composition is impregnated with the PGM component (i.e., the molecular sieve is a PGM component-substituted molecular sieve). As used herein, impregnation with the PGM component includes all forms in which the PGM component associates with the molecular sieve, such as when the PGM component is present in either the ion-exchange sites of the molecular sieve or other internal locations within the molecular sieve, or when the PGM is present on the surface of the molecular sieve, or a combination of the above locations. Thus, as used herein, the term "PGM-substituted" encompasses the term "ion-exchanged". As used herein, "ion-exchanged" or "PGM-exchanged" means that the PGM is supported on or within the molecular sieve material. At least a portion of the PGM is in ionic form, and in one or more embodiments, a portion of the PGM may be in zero-valent or metallic form, or in the form of metal oxide aggregates. In some embodiments, the disclosed NO x The adsorbent composition is described as containing a molecular sieve "containing" the PGM component (or containing a PGM component "associated" with the molecular sieve). In such examples, "containing" (or "associated") is understood to mean that the PGM component is present at the ion exchange site of the molecular sieve, on the surface of the molecular sieve, or both at the ion exchange site and on the surface of the molecular sieve. In some embodiments, the disclosed NO x Adsorbent compositions may be described as containing molecular sieves that "contain" PGMs, in which case "contains" is understood to mean that PGMs are present in the ion exchange sites of the molecular sieves, on their surface, or both.

[0079] The term “PGM component” refers to any component containing PGMs (e.g., ruthenium (Ru), rhodium (Rh), osmium (Os), iridium (Ir), palladium (Pd), and / or platinum (Pt)). When we say “PGM component,” we mean any component that allows the presence of PGMs in any valence state, but in relation to the disclosed NOx adsorbent compositions, the PGMs are generally in a form that enables NOx adsorption (e.g., including, but not limited to, ion-exchange cation forms). Terms such as “platinum (Pt) component,” “rhodium (Rh) component,” “palladium (Pd) component,” “iridium (Ir) component,” and “ruthenium (Ru) component” refer to the respective platinum group metal compounds, complexes, or similar substances that decompose or are converted to a catalytically active form, usually metal or metal oxide, during the calcination or use of the catalyst. Certain exemplary PGM components that may find specific use in the NOx adsorbent compositions disclosed herein include palladium, platinum, rhodium, or combinations thereof. Furthermore, in some embodiments, the PGM component is palladium as the sole PGM component, but mixtures of PGM components can also be used. When a mixture is used, the PGM component may contain two different platinum group metals in a mass ratio, for example, about 1:10 to about 10:1. For example, in some embodiments, the PGM component is platinum and palladium.

[0080] The molecular sieve of the NOx adsorbent composition disclosed herein has a PGM content of at least 1% by mass, for example, at least 5% by mass, more specifically, at least 10% by mass, for example, at least 25% by mass, and for example, at least 50% by mass of PGM located within the pores of the molecular sieve.

[0081] In some embodiments, the molecular sieve of the NOx adsorbent composition disclosed herein may be substituted with further metals, such as base metals. Thus, the molecular sieve of the NOx adsorbent composition may contain the molecular sieve, the PGM component, and optionally, a base metal. It can be said that the molecular sieve contains the PGM component and optionally a base metal. The base metal can be selected from iron (Fe), copper (Cu), manganese (Mn), chromium (Cr), cobalt (Co), nickel (Ni), zinc (Zn), and tin (Sn), and mixtures of two or more of them. In some embodiments, the base metal is selected from Fe, Cu, Co, and mixtures thereof. Alternatively, the molecular sieve may be substantially base-metal-free. In some embodiments, the molecular sieve is base-metal-free. In some embodiments, the NOx adsorbent composition is substantially base-metal-free, containing no further active metals beyond the PGM component.

[0082] The concentration of the PGM component may vary, but is typically about 0.01% to about 6% by mass relative to the total dry mass of the molecular sieve. The PGM component may be present in the range of, for example, about 0.1%, 0.2%, 0.5%, 0.7%, 0.9%, or about 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, or about 6% by mass relative to the total dry mass of the molecular sieve. The mass of the PGM component is measured and reported as the mass of the metal (e.g., palladium). The total dry mass of the molecular sieve includes the added / replaced metal (i.e., palladium).

[0083] As mentioned above, NOx adsorbent catalyst compositions in some embodiments include a magnetic material that allows the catalyst article to be inductively heated by the application of an electromagnetic field. However, NOx adsorbent catalyst compositions do not include a magnetic material in all embodiments (for example, as will be described in more detail below, the magnetic material may instead be associated with the substrate).

[0084] NO disclosed herein xThe adsorbent composition can be readily manufactured by processes well known in the art. Disclosed NO x Adsorbents can be manufactured in some embodiments via an inducement wetting impregnation method. Typically, a metal precursor (e.g., a PGM component) is dissolved in an aqueous or organic solution, and then the metal-containing solution is added to the material to be impregnated (e.g., a molecular sieve). The material has a pore volume essentially equal to the volume of the added solution. The solution is drawn into the pores of the material by capillary action. If an amount of solution exceeding the pore volume of the material is added, the transport of the solution changes from capillary action to diffusion, and the rate slows down considerably. The impregnated material can then be dried and optionally calcined to remove volatile components in the solution and precipitate the metal on the surface of the material. The maximum loading amount is limited by the solubility of the precursor in the solution. The concentration profile of the impregnated material depends on the mass transport conditions in the pores during impregnation and drying.

[0085] For example, PGM component precursors (e.g., palladium nitrate) can be supported on molecular sieves by impregnation, adsorption, ion exchange, incipient wetting, precipitation, etc. Non-limiting examples of suitable PGM precursors include palladium nitrate, tetraamminepalladium nitrate, tetraammineplatinum acetate, and platinum nitrate. Alternatively, a PGM colloidal dispersion as described above can be used. During the calcination process, or at least during the initial stages of catalyst use, such compounds are converted into catalytically active forms of the metal or its compounds.

[0086] Base material According to one or more embodiments, NO x The substrate for the adsorbent composition can be made of any material commonly used in the manufacture of automotive catalysts, and is typically composed of a metal or ceramic honeycomb structure. The substrate typically provides multiple walls to which the catalyst composition is coated and adhered, thereby acting as a carrier for the catalyst composition.

[0087] Exemplary metal substrates comprise heat-resistant metals and metal alloys, such as titanium and stainless steel, as well as other alloys in which iron is a substantial or major component. Such alloys can be selected from nickel, chromium, and / or aluminum, and the total amount of these metals may advantageously include at least 15 mass% of the alloy, for example, 10-25 mass% of chromium, 3-8 mass% of aluminum, and up to 20 mass% of nickel. The alloy may also contain small or trace amounts of other metals selected from manganese, copper, vanadium, titanium, etc. The surface or metal carrier can be oxidized at a high temperature, for example above 1000°C, to form an oxide layer on the surface of the substrate, thereby improving the corrosion resistance of the alloy and facilitating the adhesion of the wash coat layer to the metal surface.

[0088] The ceramic materials used to construct the base material include suitable refractories selected from cordierite, mullite, cordierite-α alumina, silicon nitride, zircon mullite, spodumene, alumina silica magnesia, zircon silicate, sillimanite, magnesium silicate, zircon, petalite, α alumina, aluminosilicate, and others.

[0089] In some embodiments, as mentioned above, the magnetic material associated with the catalyst article is contained within the substrate itself. In some such embodiments, the magnetic material can be 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. Such combination can be carried out by mixing, grinding, shaking, etc., to promote the overall dispersion of the magnetic material. The resulting mixture is then formed into a substrate (e.g., by extrusion or pouring into a mold, followed by firing and drying). General methods for producing ceramic substrates are known, for example, described in Corning U.S. Patents 5,314,650, 5,403,787, 6,455,124, 8,673,206 and 9,808,794, all of which are incorporated herein by reference in their entirety. In other embodiments, the magnetic material can be introduced into the pores of a pre-formed catalyst substrate. Figures 3A and 3B are schematic diagrams of cross-sections of substrates showing two non-limiting catalyst substrates incorporating magnetic materials. As shown, the exemplary substrate includes a channel 10 formed by walls 12 extending through the substrate from upstream to downstream, and the magnetic material 20 is dispersed within the walls 12 or within pores within the walls 12. In Figure 3A, black represents the substrate material and white dots represent the magnetic material, and in Figure 3B, black represents the substrate, white irregular areas represent pores within the substrate, and the black dots therein represent the magnetic material. Further details are provided in U.S. Provisional Patent Application No. 63 / 087,640, dated October 5, 2020, by Caudle et al., which is also incorporated herein by reference in its entirety.

[0090] As a substrate, a suitable substrate can be used, such as a monolithic flow-through substrate, which has multiple fine, parallel gas flow channels extending from the inlet to the outlet surface of the substrate, and whose channels are 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, so 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 selected from trapezoidal, rectangular, square, sinusoidal, hexagonal, elliptical, circular, etc. Such structures can contain gas inlet openings (i.e., "cells") with a cross-sectional area of ​​approximately 60 to approximately 1200 or more (cpsi) per square inch, more typically approximately 300 to approximately 600 cpsi. The wall thickness of the flow-through substrate varies, and its typical range can be 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, it will be understood that the disclosed subject matter is not limited to specific substrate types, materials, or shapes.

[0091] In another embodiment, the substrate may be a wall-flow substrate, where each passage is blocked by a non-porous plug at one end of the substrate body, in which case the passages are alternately blocked at both 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, e.g., about 100 cpsi to 400 cpsi, more typically about 200 cpsi to about 300 cpsi. The cross-sectional shape of the cells can vary as described above. Wall-flow substrates typically have a wall thickness of 0.002 inches to 0.1 inches. Typical commercially available wall-flow substrates are made 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 can also be used as wall-flow filter substrates. However, it will be understood that the disclosed subject matter 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., a 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).

[0092] Figures 1 and 2 show an exemplary substrate 2 in the form of a flow-through substrate coated with the wash-coat composition described herein. Referring to Figure 1, the exemplary substrate 2 is cylindrical in shape and has an outer surface 4 of the cylinder, 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 fine, parallel gas flow passages 10 formed therein. As seen in Figure 2, the passages 10 are formed by walls 12 and extend through the carrier 2 from the upstream end face 6 to the downstream end face 8, and the passages 10 are not blocked in order to allow the flow of a fluid, such as a gas flow, through the gas passages 10 in the longitudinal direction of the carrier 2. As can be readily seen in Figure 2, the walls 12 are constructed to be dimensioned such that the gas flow passages 10 have a substantially regular polygonal shape. As shown, the catalyst composition can optionally be applied as 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 covering 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 2.

[0093] When describing the amounts of washcoat or catalyst metal components or other components of the composition, it is convenient to use the mass unit of the component per unit volume of the catalyst substrate. Therefore, in this specification, grams per cubic inch ("g / in") are used. 3 ) and grams per cubic foot ("g / ft") 3 The unit '' is used to mean the mass of the component per unit volume of the substrate, including the volume of voids in the substrate. In addition, other units such as g / L, which represent mass per unit volume, are sometimes used. The total amount of catalyst composition (including catalyst metal and support material) supported on catalyst substrates such as monolithic flow-through substrates is usually about 0.5 g / in. 3 ~approximately 6g / in 3 For example, approximately 1 g / in 3 ~approximately 5g / in 3 The total loading amount of PGM or base metal components excluding the carrier material is typically about 5 g / ft. 3 ~about 200g / ft 3 (For example, 10g / ft3 ~about 100g / ft 3 These masses per unit volume are typically calculated by weighing the catalyst substrate before and after treatment with the catalyst washcoat composition, and it should be noted that these masses essentially represent a solvent-free catalyst coating, as the treatment process involves drying and calcining the catalyst substrate at high temperatures, since all moisture in the washcoat slurry is essentially removed.

[0094] In some embodiments, NO provided herein x The amount of PGM component in the adsorbent composition can be expressed as the mass per unit volume of the substrate. For example, in a particular embodiment, NO x The amount of PGM component in the adsorbent composition is approximately 10 g / ft 3 ~140g / ft 3 Or approximately 40g / ft 3 ~about 100g / ft 3 (Based on the volume of the substrate material on which the catalyst is placed).

[0095] NO x Adsorbent compositions generally have a concentration of approximately 0.3 g / in based on the volume of the substrate. 3 From 5.5g / in 3 , or approximately 0.4g / in 3 Approximately 0.5g / in 3 Approximately 0.6g / in 3 Approximately 0.7g / in 3 , about 0.8g / in 3 Approximately 0.9g / in 3 Or approximately 1.0 g / in 3 Approximately 1.5g / 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 It is present on the substrate at concentrations up to that level.

[0096] Substrate coating method The catalyst composition can be used in the form of a packed bed of powder, beads, or extruded granules. However, in some advantageous embodiments, the catalyst composition is coated onto a substrate. The catalyst composition can be mixed with water to form a slurry (if 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 of, for example, about 3 to about 5.

[0097] If present, the alumina binder is typically about 0.02 g / in 3 ~Approximately 0.5g / in 3 It is used in this quantity. As an alumina binder, for example, it can be selected from boehmite, gamma alumina, or delta / theta alumina.

[0098] 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, more specifically about 30% to 40% by mass. In one embodiment, the slurry after grinding is characterized by a D90 particle size of about 10 microns to about 50 microns (e.g., 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.

[0099] 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.

[0100] In some embodiments, the substrate is immersed in the slurry one or more times, or otherwise coated with the slurry. The coated substrate is then dried at a high temperature (e.g., 100°C to 150°C) for a certain period of time (e.g., 1 to 3 hours), and then fired by heating at, for example, 400°C to 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.

[0101] 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.

[0102] 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 path on a single substrate.

[0103] When incorporating magnetic materials into a catalyst composition, the substrate can be coated after the magnetic material has been added to the catalyst composition. For example, it is advantageous to add the magnetic material to the washcoat slurry before the grinding step. As a result, the grinding action can promote the dispersion of the magnetic material throughout the slurry.

[0104] Waste disposal system This disclosure also provides an exhaust treatment system incorporating the catalyst compositions described herein. The catalyst articles disclosed herein can typically be 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.

[0105] Figure 4 shows NO of the disclosure suitable for induction heating 40. x The adsorbent catalyst article is shown. As illustrated, this adapted catalyst article is catalyst article 60 (associated with the substrate and NO as described herein). xThe catalyst article 60 comprises a magnetic material (including an adsorbent composition) and / or is associated with the catalyst composition contained within and / or on the substrate itself. An electric coil 62 surrounds the catalyst article 60 to provide an alternating magnetic field 64 suitable for induction heating of the magnetic material associated with the catalyst article 60. The electric coil 62 is electrically connected to a power supply 66 that can supply 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 100 kHz to 10000 kHz.

[0106] Figure 5 shows an exemplary emissions treatment system. This figure shows a schematic diagram of emissions treatment system 50, and arrow 52 indicates engine emissions (typically NO). x The diagram shows the direction of travel of gaseous pollutants (including particulate matter). As shown in the diagram, this system apparatus is adapted for induction heating and includes a catalyst article 60 (NO on a substrate) as disclosed herein. x The system comprises an adsorbent composition. The system 50 further comprises a downstream SCR catalyst 70, which is in fluid communication with the catalyst article 60. The composition of the downstream SCR catalyst varies, and NO x It may contain any of the components for reducing. Certain SCR compositions may contain metal-promoting molecular sieving materials (e.g., copper- or iron-promoting zeolites) as described, for example, in Zones Patent Nos. 4,544,538 and 6,709,644, and U.S. Patent No. 8,883,119 by Bull et al. These documents are incorporated herein by reference in their entirety. However, SCR compositions are not limited thereto and may alternatively contain, for example, mixed metal oxide compositions (e.g., vanadia / titania), and in one embodiment, they may comprise a ceria support containing niobia and a base metal oxide dopant, as disclosed, for example, in BASF International Patent Application Publication No. WO2019 / 069232, which is incorporated herein by reference in its entirety.

[0107] SCR catalyst 70 generally reacts with NO in the presence of a reducing agent such as ammonia or urea. xIt is effective in catalyzing the reduction of . During operation, the reducing agent is typically metered and periodically supplied to the exhaust flow via an injector from an upstream position of the SCR article. The injector is in fluid communication with the SCR article and is located upstream of the SCR article (not shown). The injector may also be associated with a reducing agent reservoir and pump. Ammonia is a typical reducing agent in SCR reactions for treating exhaust from stationary power plants, while urea is a typical SCR reducing agent used for treating exhaust from mobile emission sources. Urea is decomposed into ammonia and carbon dioxide before or on contact with the SCR catalyst, and ammonia becomes NO x It functions as a reducing agent.

[0108] An electric coil 62 surrounds the catalyst article 60 to provide an alternating magnetic field 64 suitable for the induction heating of a magnetic material associated with the catalyst article 60. The electric coil 62 is electrically connected to a power supply 66 capable of supplying alternating current to the coil, with an output power typically in the range of approximately 5 kW to 50 kW and a frequency of approximately 100 kHz to 10000 kHz. The system further comprises an optional temperature sensor 72 positioned to measure the temperature of the engine exhaust gas flowing into the SCR catalyst 70. Both the power supply 66 and the temperature sensor 72 are operably connected to a controller 68, which is configured to control the power supply and receive temperature signals from the sensors. As will be understood, the controller 68 may comprise hardware and associated software adapted to allow the controller to provide the power source with instructions to energize the electric coil 66 at the desired time for the induction heating of the magnetic material. The controller can select the induction heating time period based on various factors, such as a specific time period based on engine ignition (for example, a control system adapted to inductively heat a magnetic material for a set period following engine ignition), or at a predetermined time interval, for example, based on a specific temperature setpoint associated with the temperature sensor 72.

[0109] Advantageously, the controller has a temperature sensor 72 associated with the SCR catalyst 70 that is NO xThe catalyst article 60 can be induction heated once it reaches a temperature sufficient for NO conversion. x The NO is desorbed from the catalyst article 60 so that it can be effectively treated by the SCR catalyst 70. The temperature at which the SCR catalyst 70 becomes effective (this is generally when induction heating of the catalyst article 60 is initiated and NO is used for treatment) x The predetermined temperature (which is sensed by the sensor 72 that emits the catalyst) can vary depending on the exact SCR catalyst composition used. However, in some embodiments, this predetermined temperature can be about 180°C or about 200°C.

[0110] It should be noted that the illustrated embodiments are merely examples of the subject matter disclosed, and other configurations are possible in accordance with this disclosure. For example, although shown on separate “bricks,” the MX adsorbent composition and the downstream SCR catalyst composition may, in some embodiments, be present on the same brick, for example, in a zone configuration. In such embodiments, the electric coil 66 may surround all or only a portion of the brick (for example, only a portion of the brick on which the NOx adsorbent composition is deposited).

[0111] In some embodiments, the exhaust treatment system includes a second selective catalytic reduction (SCR) catalyst, an SCR catalyst coated on a particulate filter (SCRoF), an ammonia or ammonia precursor injection component, a diesel oxidation catalyst (DOC), a catalytic soot filter (CSF), or ammonia oxidation (AMO). x ) Further contains one or more catalysts.

[0112] DOC or CSF catalysts typically contain one or more PGM components impregnated on a metal oxide support such as alumina, and optionally further contain an oxygen storage component (OSC) such as ceria or ceria / zirconia, and usually achieve oxidation of both hydrocarbons and carbon monoxide.

[0113] LNT catalysts generally consist of one or more PGM components impregnated onto a support, and NO xIt contains a component for capturing (e.g., ceria and / or alkaline earth metal oxides). The LNT catalyst adsorbs NO x under lean conditions and reduces the accumulated NO x to nitrogen under rich conditions.

[0114] The SCR catalyst is 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, a hydrocarbon, hydrogen, and / or ammonia. The SCR catalyst typically includes a molecular sieve (e.g., zeolite) ion-exchanged with a promoter metal such as copper or iron, and exemplary SCR catalysts include FeBEA, FeCHA, and CuCHA.

[0115] The TWC catalyst refers to a catalyst having the function of three-way conversion that substantially simultaneously converts hydrocarbons, carbon monoxide, and nitrogen oxides. Usually, the TWC catalyst includes one or more platinum group metals such as palladium and / or rhodium, optionally platinum, and an oxygen storage component. Under rich conditions, the TWC catalyst usually produces ammonia.

[0116] AMO x The catalyst refers to an ammonia oxidation catalyst, which is a catalyst containing one or more metals suitable for converting ammonia and is generally supported on a support material such as alumina or titania. Exemplary AMO x The catalyst includes a copper zeolite in cooperation with a supported platinum group metal (e.g., platinum impregnated on alumina).

[0117] 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. Methods for producing catalyst compositions that can be used in a system in combination with the NOx adsorption catalysts disclosed herein, as well as other known methods, 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.

[0118] While the subject matter disclosed herein has been described through specific embodiments and their uses, many modifications and variations can be made to these embodiments and their uses by those skilled in the art without departing from the scope of disclosure as described in the claims. Furthermore, various aspects of the disclosed subject matter may be used for uses other than those specifically described herein.

Claims

1. Nitrogen oxides (NOx) are removed from catalytic converters used to treat exhaust gas flows from diesel engines or lean-burn gasoline engines. ｘ A method for adsorbing and detaching ) The exhaust gas flow is brought into contact with the catalyst article. Here, the catalyst article is formed by arranging or impregnating a support material with a platinum group metal (PGM) component. ｘ It comprises an adsorbent composition and a substrate, The exhaust gas flow is brought into contact with the selective catalytic reduction (SCR) catalyst composition downstream of the NOx adsorbent composition, and To monitor the temperature of the SCR catalyst composition, Here, the NO ｘ The adsorbent composition is NO ｘ It is effective for storing at temperatures below 225°C. Here, the catalyst article comprises a magnetic material that can be inductively heated in response to an applied alternating electromagnetic field; and Here, the catalyst article further comprises a conductor associated therewith to receive an electric current and generate an alternating electromagnetic field in response, the conductor being arranged such that the generated alternating electromagnetic field is applied to at least a portion of the magnetic material; and By passing an electric current through the conductor, the conductor is intermittently excited to generate an alternating current electromagnetic field, which inductively heats the magnetic material and generates the NO ｘ The adsorbent composition is heated to a temperature exceeding 225°C, and NOx is removed from the NOx adsorbent composition. ｘ To break free from Includes, Here, intermittent excitation is performed when the temperature of the SCR catalyst composition rises above a predetermined temperature. A method further comprising maintaining the NOx adsorbent composition at a temperature higher than 225°C, as long as the SCR catalyst composition exceeds the predetermined temperature.

2. The method according to claim 1, wherein intermittent excitation is performed only when the conductor is suitable for feedback control and the substrate has a temperature of less than 225°C.

3. The aforementioned NO ｘ The method according to claim 1 or 2, wherein the adsorbent composition and the SCR catalyst composition are located on the same substrate.

4. The aforementioned NO ｘ The method according to claim 1 or 2, wherein the adsorbent composition and the SCR catalyst composition are located on separate substrates.

5. The method according to any one of claims 1 to 4, wherein the predetermined temperature is approximately 180°C or approximately 200°C.

6. The method according to any one of claims 1 to 5, further comprising removing the current when the SCR catalyst composition is below the predetermined temperature.

7. A system for processing exhaust gas flow from a diesel engine or lean-burn gasoline engine using the method according to any one of claims 1 to 6, An NO adsorbent composition in which a platinum group metal (PGM) component is disposed on a carrier material or impregnated in the carrier material, and a catalyst article comprising a substrate ｘ ​ Here, the aforementioned NO ｘ The adsorbent composition is NO ｘ It is effective for storing at temperatures below 225°C, and at temperatures above 225°C, NOx is removed. Here, the catalyst article comprises a magnetic material that can be inductively heated in response to an applied alternating electromagnetic field. A conductor for receiving an electric current and generating an alternating current electromagnetic field in response, wherein the generated alternating current electromagnetic field is applied to at least a portion of the magnetic material, and The aforementioned NO ｘ SCR catalyst composition downstream of adsorbent composition, and A device for monitoring the temperature of the SCR catalyst composition, A system equipped with this feature.

8. The system according to claim 7, wherein the NOx adsorbent composition and the SCR catalyst composition are on the same substrate.

9. The system according to claim 7, wherein the NOx adsorbent composition and the SCR catalyst composition are located on separate substrates.

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