Emission treatment system for reducing NOx in the exhaust stream of a lean-burning engine and method for reducing NOx in the exhaust stream of a lean-burning engine.

Abstract

EMISSION TREATMENT SYSTEM FOR REDUCING NOX IN THE EXHAUST STREAM OF A LEAN-BURNING ENGINE AND METHOD FOR REDUCING NOX IN THE EXHAUST STREAM OF A LEAN-BURNING ENGINE. This disclosure relates to an emission treatment system for reducing NOx in the exhaust stream of a lean-burning engine. The emission treatment system includes a lean NOx capture system (LNT) in fluid communication with, and downstream of, the lean-burning engine and a low-temperature NOx adsorber (LTNA) in fluid communication with, and downstream of, the LNT. Furthermore, a method is provided for reducing NOx in the exhaust stream of a lean-burning engine using the disclosed system.

Description

"Emission treatment system for reducing NOx in the exhaust stream of a lean-burning engine and method for reducing NOx in the exhaust stream of a lean-burning engine"

[0001] This application claims the priority benefit of Provisional Application No. U.S. 62 / 947,780, filed December 13, 2019, the contents of which are incorporated by reference herein in their entirety.

[0002] This disclosure generally refers to emission treatment systems and methods suitable for treating exhaust gas streams from lean-burning engines containing nitrogen oxides (NOx).

[0003] Environmental regulations for emissions from internal combustion engines are becoming increasingly stringent worldwide. The operation of a lean-burn engine, for example, a diesel engine, provides the user with excellent fuel economy due to its operation at high air / fuel ratios under lean fuel conditions. However, diesel engines also emit exhaust gas emissions containing particulate matter (PM), unburned hydrocarbons (HC), carbon monoxide (CO), and nitrogen oxides (NOx), where NOx describes various chemical species of nitrogen oxides, including nitrogen monoxide (NO) and nitrogen dioxide (NO2), among others. NOx are harmful components of air pollution. Several methods have been used for the treatment of gas mixtures containing NOx to reduce air pollution.

[0004] An effective method for reducing NOx from lean-burn engine exhaust requires reacting NOx under lean-burn engine operating conditions with a suitable reducing agent in the presence of a component of Petition 870240108964, dated 12 / 20 / 2024, page 12 / 87 2 / 66 Selective catalytic reduction (SCR) catalyst. The SCR process can use a reducing agent, such as ammonia or a hydrocarbon in the presence of atmospheric oxygen, resulting in the formation predominantly of nitrogen and vapor: 4NO + 4NH3 + O2 → 4N2 + 6H2O (standard SCR reaction) 2NO2 + 4NH3 + O2 → 3N2 + 6H2O (slow SCR reaction) NO + NO2 + 2NH3 → 2N2 + 3H2O (fast SCR reaction)

[0005] Current catalysts employed in the SCR process include molecular sieves, such as zeolites, ion exchange with a catalytic metal, such as iron or copper. A useful SCR catalyst component is capable of effectively catalyzing the reduction of the NOx exhaust component at temperatures below 600 °C so that reduced NOx levels can be achieved even under low load conditions, which is associated with lower exhaust temperatures.

[0006] One problem encountered in the treatment of automotive exhaust gas streams is the so-called "cold start" period, which is the period of time at the beginning of the treatment process when the exhaust gas stream and the exhaust gas treatment system are at low temperatures (e.g., below 150 °C). At these low temperatures, exhaust gas treatment systems generally do not exhibit sufficient catalytic activity to effectively treat HC, NOx, and / or C. In general, catalytic components, such as SCR catalyst components, are very effective at converting NOx to N2 at temperatures above 200 °C, but may not exhibit sufficient activity in lower temperature regions (<200 °C), which may be encountered during cold starts or prolonged low-speed city driving.Thus, there is a demand for catalytic components capable of capturing and storing low-temperature NOx emissions and releasing them at higher temperatures (e.g., > 200 °C) when catalytic components (e.g., components of...) Petition 870240108964, dated 12 / 20 / 2024, page 13 / 87 3 / 66 SCR catalyst) become effective. Considerable efforts have been made to solve this problem.

[0007] There are several ways to minimize NOx emissions during cold start periods. For example, trapping systems have been developed to store these exhaust gas emissions (e.g., HC, CO, and NOx gases) at low temperatures and subsequently release them at higher temperatures when the remaining catalytic components of the treatment system have reached sufficient catalytic activity. An example of such a system is the Lean NOx Scavenger (LNT) catalyst.

[0008] Poor NOx Scavenger (LNT) catalysts contain NOx-adsorbing components that retain NOx under certain exhaustion conditions. For example, the NOx-adsorbing components may comprise alkaline earth elements, including alkaline earth metal oxides such as magnesium (Mg), calcium (Ca), strontium (Sr) and / or barium (Ba) oxides. Other LNT catalysts may contain rare earth metal oxides as NOx-adsorbing components, such as cerium (Ce), lanthanum (La), praseodymium (Pr) and / or neodymium (Nd) oxides. LNT catalysts also contain a platinum group metal (PGM) component, such as platinum dispersed in a refractory metal oxide support (e.g., alumina), for catalytic oxidation and reduction of NOx. The PGM component serves to oxidize nitric oxide (NO) to nitrogen dioxide (NO2). The LNT catalyst operates under cyclic lean exhaustion (trap mode) and rich exhaustion (regeneration mode) conditions.Under poor conditions, the LNT catalyst traps and stores NOx as an inorganic nitrate (for example, where the NOx-adsorbent component is barium oxide (BaO) or barium carbonate (BaCO3)), it is converted to barium nitrate (Ba(NO3)2) after reaction with (“trapping”) NOx. The NOx-adsorbent component then releases the NOx. Petition 870240108964, dated 12 / 20 / 2024, page 14 / 87 4 / 66 trapped and the PGM component reduces NOx to N2 under stoichiometric or transient rich engine operating conditions, or under lean engine operation with external fuel injected into the exhaust to induce rich conditions. The general operating principle of LNT includes that certain metal compounds (e.g., alkaline earth metal carbonates) undergo a carbonate / nitrate conversion, as the dominant pathway, during lean / rich operations according to the following equations:

[0009] Oxidation of NO to NO2 (Poor Condition) 2NO + O2 —> 2NO2(1)

[0010] NOx Storage as Nitrate (Trapping Mode) 2NO2 + MCO3 + ½O2 —> M(NO3)2 + CO2(2)

[0011] NOx release (rich condition) M(NO3)2 + 2CO —> MCO3 + NO2 + NO + CO2(3)

[0012] Reduction of NOx to N2 (regeneration mode) NO2 + CO —> NO + CO2(4) 2NO + 2CO —> N2 + 2CO2(5)

[0013] The LNT catalyst promotes the storage of NOx during a lean operating period (λ > 1.0) (e.g., according to equations (1) and (2)), and during a rich period (λ < 1.0), catalyzes the release and reduction of stored NOx to N2 (e.g., according to equations (3), (4) and (5)), where λ represents the air / fuel ratio. In equations (2) and (3), M represents a metal cation, such as a divalent metal cation. M can also be included in a monovalent or trivalent metal compound, in which case the equations need to be rebalanced.

[0014] Another method of trapping NOx is with a low-temperature NOx adsorbent (LT-NA). Several varieties of LT-NAs are known. A relatively new LT-NA useful for trapping Petition 870240108964, dated 12 / 20 / 2024, page 15 / 87 5 / 66 of NOx at low temperature utilizes a palladium (Pd) exchanged zeolite to capture NO without catalytic pre-oxidation to NO2 (which is slow at T < 180 °C). In theory, an LT-NA can be used in combination with an LNT to effectively capture NOx emissions at low temperatures. However, the use of an LT-NA in conjunction with an LNT is complicated by the finding that the rich purge required to regenerate the LNT is destructive to the NOx storage capacity of the LT-NA. To avoid such an event, Patent Application Publication No. US 2017 / 0096922 describes a system with an LT-NA (referred to as a passive NOx adsorber; “PNA”) disposed upstream of an LNT. The rich condition required to regenerate the LNT is produced by injecting fuel from a fuel injector placed downstream of the NOx absorber and upstream of the LNT. In this configuration, LNT can be regenerated without exposing the upstream NOx adsorber to reducing gases.However, this configuration is inherently more complicated to implement.

[0015] Thus, there is a need for a system to capture and remove NOx emissions generated at low temperatures, incorporating an LNT and an LT-NA in a configuration that does not require an additional fuel injection device.

[0016] This disclosure generally provides exhaust gas treatment systems exhibiting enhanced NOx adsorption under low temperature conditions and methods for treating NOx-containing exhaust gas streams using such treatment systems. Such systems generally comprise a poor NOx scavenger (LNT) and a low-temperature NOx adsorber (LT-NA) suitable for adsorbing NOx at low temperatures and releasing the captured NOx at elevated temperatures. In particular, such systems comprise an LNT followed downstream by an LT-NA. The use of an LT-NA downstream of an LNT would normally be prohibited by the fact that the storage function of the LT-NA is strongly impaired by Petition 870240108964, dated 12 / 20 / 2024, page 16 / 87 6 / 66 rich deNOx condition used to regenerate the LNT. Surprisingly, it was found that by placing the LT-NA downstream of the LNT and controlling the composition and timing of the deNOx reducing pulse, the LT-NA is protected from exposure to reducing agents by the oxygen storage function of the LNT, thus extending the useful low-temperature trapping range of the system for cold-start NOx emissions.

[0017] Consequently, in a first aspect, an emission treatment system is provided for reducing NOx in an exhaust stream from a lean-burn engine, the emission treatment system comprising a lean-burn NOx scavenger (LNT) comprising an oxygen storage component (OSC) and a first platinum group metal (PGM) component, wherein the LNT is in fluid communication with and downstream of the lean-burn engine; and a low-temperature NOx adsorber (LT-NA) comprising a molecular sieve comprising a second PGM component, wherein the LT-NA is in fluid communication with and downstream of the LNT.

[0018] In some embodiments, the LNT is placed on a first substrate and the LT-NA is placed on a second substrate. In some embodiments, the first substrate is a honeycomb substrate in the form of a continuous flow filter and the second substrate is an alveolar substrate in the form of a continuous flow filter or a wall flow filter.

[0019] In some embodiments, the LNT and the LT-NA are arranged on the same substrate in a zoned configuration, the substrate having an inlet end and an outlet end defining a total length, wherein the LNT is arranged on the substrate extending from the inlet end to a length of about 20% to about 100% of the total length; and wherein the LT-NA is arranged on the substrate extending from the outlet end to a length of about 20% to Petition 870240108964, dated 12 / 20 / 2024, page 17 / 87 7 / 66 approximately 100% of the total length. In some embodiments, the LNT is placed directly on the substrate covering 100% of the total length; and the LT-NA is placed on the LNT, covering from approximately 20% to approximately 80% of the total length. In some embodiments, the LT-NA is placed directly on the substrate covering 100% of the total length; and the LNT is placed on the LT-NA, covering from approximately 20% to approximately 80% of the total length. In some embodiments, the LNT is placed directly on the substrate and the LT-NA is placed directly on the substrate. In some embodiments, the substrate is an alveolar substrate in the form of a continuous flow filter.

[0020] In some embodiments, the OSC comprises ceria. In some embodiments, the OSC further comprises one or more selected from zirconia, alumina, silica, titania, lantana, barium, praseodymia, yttria, samaria, gadolinia and combinations thereof.

[0021] In some embodiments, the first PGM component is chosen from platinum, palladium, rhodium, and combinations thereof. In some embodiments, the first PGM component is palladium. In some embodiments, the second PGM component resides in ion-exchange sites in the molecular sieve.

[0022] In some embodiments, the second PGM component is chosen from platinum, palladium, rhodium, and combinations thereof. In some embodiments, the second PGM component comprises a mixture of platinum and palladium.

[0023] In some embodiments, the molecular sieve has a frame type chosen from ABW, ACO, AEI, AEL, AEN, AET, AFG, AFI, AFN, AFO, AFR, AFS, AFT, AFX, AFY, AHT, ANA, APC, APD, AST, ASV, ATN, ATO, ATS, ATT, ATV, AVL, AWO, AWW, BCT, BEA, BEC, BIK, BOF, BOG, BOZ, BPH, BRE, BSV, CAN, CAS, CDO, CFI, CGF, CGS, CHA, CHI, CLO, CON, CZP, DAC, DDR, DFO, DFT, DOH, DON, EAB, EDI, EEI, EMT, EON, EPI, ERI, ESV, Petition 870240108964, dated 12 / 20 / 2024, p. 18 / 87 8 / 66 ETR, EUO, EZT, FAU, FER, FRA, GIS, GIU, GME, GON, GOO, HEU, IFR, IFY, IHW, IMF, IRN, ISV, ITE, ITG, ITH, ITW, IWR, IWS, IWV, IWW, JBW, JRY, JSR, JSR, JSR, LEV, LIT, LIO, LIO LOS, LOV, LTA, LTF, LTL, LTN, MAR, MAZ, MAY, MEL, MEP, MER, MFI, MFS, MON, MOR, MOZ, MRE, MSE, MSO, MTF, MTN, MTT, MVY, MTW, MWF, MWW, NAB, NAT, NES, NES, NPO, NPO, NPO, OFF, NBW, NBW OKO, OSI, OSO, OWE, PAR, PAU, PCR, PHI, PON, PUN, RHO, RON, RRO, RSN, RTE, RTH, RUT, RWR, RWY, SAF, SAO, SAS, SAT, SAV, SBE, SBS, SBT, SCO, SEW, SFE, SFF, SFF, SFG, SSF, SSF, SSF, SSF, SSFW, SSFW Mixtures of SGF, SGT, SIV, SOD, SOF, SOS, SSF, SSY, STF, STI, STO, STT, STW, SVR, SZR, TER, THO, TON, TSC, TUN, UEI, UFI, UOS, UOZ, USI, UTL, UWY, VET, VFI, VNI, VSV, WSVEN, or ZON, YUG and ZON intergrowths of the same. In some embodiments, the molecular sieve has a framing type chosen from AFX, CHA, FER. In some embodiments, the molecular sieve is an aluminosilicate zeolite.In some embodiments, the molecular sieve is chosen from Type A, beta zeolite, chabazite, erionite, faujasite, ferrierite, mordenite, silicalite, SSZ-13, stilbite, ZSM-5, ZSM-11, ZSM-23, ZSM-48, zeolite X and zeolite Y. In some embodiments, the molecular sieve is ferrierite.

[0024] In some embodiments, the LNT is configured to remove reducing gases present during a rich condition; and in which the LNT is configured to prevent reducing gases from entering the downstream LT-NA.

[0025] In some embodiments, the emission treatment system further comprises a lambda sensor located downstream of the LNT. In some embodiments, the emission treatment system further comprises one or more selected from a selective catalytic reduction (SCR) catalyst, an ammonia precursor or ammonia injection component, a diesel oxidation catalyst (DOC), a catalyzed soot filter (CSF), or an ammonia oxidation catalyst (AMOX), and combinations thereof. In some embodiments, the SCR is downstream and in fluid communication with Petition 870240108964, dated 12 / 20 / 2024, page 19 / 87 9 / 66 LT-NA.

[0026] In another aspect, a method is provided for reducing NOx in an exhaust stream from a lean-burn engine, wherein the method comprises bringing the exhaust gas stream into contact with the emission treatment system, as disclosed in this document. In some embodiments, the method further comprises operating the lean-burn engine in a rich mode that produces a rich exhaust stream containing reducing gases comprising hydrocarbons (HC) and carbon monoxide (CO); passing the rich exhaust gas stream through the LNT, thereby creating a reducing atmosphere therein; and regenerating the LNT in the reducing atmosphere; wherein the lean-burn engine is operated in rich mode to sufficiently regenerate the LNT without exceeding the adsorption capacity of the LNT for the reducing gases.In some embodiments, the method also involves monitoring the exhaust stream exiting the LNT with a lambda sensor; and returning the lean-burning engine to a lean mode to finish operating the lean-burning engine in rich mode according to a monitoring result; thus avoiding exposure of the LT-NA to the reducing atmosphere.

[0027] These and other features, aspects, and advantages of the disclosure will be evident from a reading of the detailed description that follows, together with the accompanying drawings, which are briefly described below. The disclosure includes any combination of two, three, four, or more of the embodiments mentioned above, as well as combinations of any two, three, four, or more features or elements set forth in this disclosure, regardless of whether such features or elements are expressly combined in a specific embodiment description herein. This disclosure is intended to be read holistically, so that any separable features or elements of the disclosed disclosure, in any of its various aspects and embodiments, are seen as Petition 870240108964, dated 12 / 20 / 2024, p. 20 / 87 10 / 66 intended to be combinable, unless the context clearly dictates otherwise. Other aspects and advantages of this disclosure will become apparent from the following. Brief Description of the Drawings

[0028] In order to provide an understanding of the embodiments of the disclosure, reference is made to the accompanying drawings, in which reference numerals refer to components of example embodiments of the disclosure. The drawings are provided for illustrative purposes only and should not be construed as limiting the scope of this disclosure. The disclosure described herein is illustrated by way of example and not as a limitation in the accompanying figures. For simplification and clarity of illustration, features illustrated in the figures are not necessarily sketched to scale. In addition, where deemed appropriate, reference identifications have been repeated between figures to indicate corresponding or analogous elements.

[0029] Figure 1A represents a perspective view of an alveolar-type substrate that may comprise a composition (e.g., Poor NOx Scavenger (LNT) and / or Low Temperature NOx Adsorber (LT-NA)) according to some embodiments of the present disclosure.

[0030] Figure 1B represents an enlarged partial cross-sectional view relative to Figure 1A and taken along a plane parallel to the end faces of the substrate of Figure 1A showing an enlarged view of a plurality of gas flow passages shown in Figure 1 in an embodiment where the substrate is a continuous flow substrate.

[0031] Figure 2 represents a cross-sectional view of a section of the alveolar-type substrate in Figure 1A, which represents a flow filter. Petition 870240108964, dated 12 / 20 / 2024, page 21 / 87 11 / 66 wall.

[0032] Figure 3A represents a cross-sectional view of a section of a substrate in which the LNT and LT-NA are arranged on the same substrate in a zoned configuration according to some embodiments of the present disclosure.

[0033] Figure 3B represents a cross-sectional view of a section of a substrate in which the LNT and LT-NA are arranged on the same substrate in a configuration of partially overlapping zones according to some embodiments of the present disclosure.

[0034] Figure 3C represents a cross-sectional view of a section of a substrate in which LNT and LT-NA are arranged on the same substrate in a layered and zoned configuration according to some embodiments of the present disclosure.

[0035] Figure 3D represents a cross-sectional view of a section of a substrate in which LNT and LT-NA are arranged on the same substrate in an alternating layered and zoned configuration according to some embodiments of the present disclosure.

[0036] Figure 4 illustrates a schematic representation of one embodiment of an emission treatment system comprising the LNT and LT-NA, in combination with additional emission treatment system components.

[0037] Figure 5A illustrates a schematic representation of an embodiment of an emission treatment system of the present disclosure comprising an LNT disposed on a first substrate and an LT-NA disposed on a second substrate, wherein the LNT is located downstream and in fluid communication with a lean-burn engine, and the LT-NA is located downstream and in fluid communication with the LNT.

[0038] Figure 5B illustrates a schematic representation of Petition 870240108964, dated 12 / 20 / 2024, page 22 / 87 12 / 66 an embodiment of an emission treatment system of the present disclosure comprising an LNT and an LT-NA, wherein the LNT is located downstream and in fluid communication with a lean-burning engine and the LT-NA is located downstream and in fluid communication with the LNT, and wherein the LNT and the LT-NA are arranged on the same substrate.

[0039] This disclosure generally provides exhaust gas treatment systems exhibiting enhanced NOx adsorption under low temperature conditions and methods for treating NOx-containing exhaust gas streams using such treatment systems. In some embodiments, such systems comprise a lean NOx trap (LNT) followed downstream by a low-temperature NOx adsorber (LT-NA). Such systems are effective at trapping and storing NOx under cold start conditions, and releasing NOx as downstream emission treatment components reach their operating temperatures.This low-temperature adsorption performance is important when, for example, these NOx adsorption components are placed upstream of a selective catalytic reduction (SCR) catalyst that is effective at converting NOx to N2 at temperatures above 200 °C, but not sufficiently active in lower temperature regions (e.g., < 200 °C), such as during a cold start.

[0040] The use of an LT-NA downstream of an LNT can be affected, as the adsorption capacity of the LT-NA may be reduced or deactivated by the deNOx-rich condition used to regenerate the upstream LNT. To solve this problem, according to some embodiments of the present disclosure, by placing an LT-NA downstream of an LNT, and controlling the composition and timing of the deNOx reducing pulse, the LT-NA is protected from exposure to reducing agents in the gas stream. Petition 870240108964, dated 12 / 20 / 2024, page 23 / 87 13 / 66 exhaust via the LNT oxygen storage function, thus extending the system's useful low-temperature trapping range to reduce cold-start NOx emissions. Definitions

[0041] As used in this document, “a” refers to one or more of (e.g., at least one) of the following objects. As such, the terms “a,” “one or more,” and “at least one” are used interchangeably in this document. Any ranges mentioned in this document are inclusive. The term “about” is used everywhere to describe and account for small variations. For example, “about” may mean that the numeric value can be modified by ±5%, ±4%, ±3%, ±2%, ±1%, ±0.5%, ±0.4%, ±0.3%, ±0.2%, ±0.1%, or ±0.05%. All numeric values ​​are modified by the term “about,” whether explicitly stated or not. Numeric values ​​modified by the term “about” include the specific identified value. For example, "about 5.0" includes 5.0.

[0042] The term “reduction” means a decrease in quantity, caused by any means.

[0043] “AMOx” refers to a selective ammonia oxidation catalyst, which is a catalyst containing one or more metals (such as Pt, but not limited to) and a selective catalytic reduction (SCR) catalyst suitable for converting ammonia to nitrogen.

[0044] The term “associated” means, for example, “equipped with”, “connected to” or “in communication with”, for example “electrically connected” or in “fluid communication with” or otherwise connected in a way to perform a function. The term “associated” may mean directly associated or indirectly associated with, for example, through one or more other articles or elements. Petition 870240108964, dated 12 / 20 / 2024, page 24 / 87 14 / 66

[0045] The term “average particle size” is synonymous with D50, meaning that half of the particle population has a particle size above this point, and half below. Particle size refers to primary particles. Particle size can be measured by laser light scattering techniques with dispersions or dry powders, for example, according to the standard method of ASTM standard D4464. The D90 particle size distribution indicates that 90% of the particles (e.g., by number) have a Feret diameter below a certain size measured by Scanning Electron Microscopy (SEM) or Transmission Electron Microscopy (TEM) for submicron-sized particles; and a particle size analyzer for particles containing support (e.g., in micron size).

[0046] The term “catalyst” refers to a material that promotes a chemical reaction. The catalyst includes the “catalytically active species” and the “support” that carries or supports the active species. For example, zeolites are supports for the catalytically active species palladium. Similarly, refractory metal oxide particles can be a support for catalytically active metal species from the platinum group. Catalytically active species are also called “promoters” because they promote chemical reactions. For example, a present rare earth metal component containing palladium can be termed a Pd-promoted rare earth metal component. A “promoted rare earth metal component” refers to a rare earth metal component to which catalytically active species are intentionally added.

[0047] The term “catalytic article” in the disclosure means an article comprising a substrate having a catalyst coating composition.

[0048] The term “crystal size”, as used in this Petition 870240108964, dated 12 / 20 / 2024, p. 25 / 87 15 / 66 document, means the length of an edge of a crystal face, such as the longest edge, provided the crystals are not needle-shaped. Direct measurement of crystal size can be performed using microscopy methods such as SEM and TEM. For example, SEM measurement involves examining the morphology of materials at high magnifications (such as 1,000x to 10,000x). The SEM method can be performed by distributing a representative portion of zeolite powder on a suitable support so that individual particles are reasonably evenly distributed across the field of view, for example, at a magnification of 1,000x to 10,000x. From this population, a statistically significant sample of random individual crystals (e.g., 50 to 200) is examined, and the longest dimensions of the individual crystals parallel to the horizontal line of the straight edge are measured and recorded.

[0049] The term “configured”, as used in the description and claims, is intended to be an open term, as are the terms “comprising” or “containing”. The term “configured” is not intended to exclude other possible articles and elements. The term “configured” may be equivalent to “adapted”.

[0050] The term “CSF” refers to a catalyzed soot filter, which is a wall-flow monolith. A wall-flow filter consists of alternating inlet and outlet channels, where the inlet channels are blocked at the outlet end and the outlet channels are blocked at the inlet end. An exhaust gas stream carrying soot entering the inlet channels is forced to pass through the filter walls before exiting the outlet channels. In addition to soot filtration and regeneration, a CSF may carry oxidation catalysts to oxidize CO and HC to CO2 and H2O, or oxidize NO to NO2 to accelerate downstream SCR catalysis or to facilitate the oxidation of soot particles at lower temperatures. Petition 870240108964, dated 12 / 20 / 2024, page 26 / 87 16 / 66 An SCR catalyst composition can also be directly coated onto a wall-flow filter, which is called SCRoF.

[0051] The term “DOC” refers to a diesel oxidation catalyst, which converts hydrocarbons and carbon monoxide in the exhaust gas of a diesel engine. In some embodiments, a DOC comprises 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, promoters and / or stabilizers.

[0052] As used in this document, the phrase “emission treatment system” refers to a combination of two or more catalyst components, for example, a combination of an LNT-LT-NA as disclosed in this document and one or more additional catalyst components which may be, for example, a CSF, a DOC or a selective catalytic reduction (SCR) catalytic article.

[0053] In general, the term “effective” means, for example, from about 35% to 100% effective, 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%, in relation to the defined catalytic activity or storage / release activity, by weight or mole.

[0054] The term “exhaust stream” or “exhaust gas stream” refers to any combination of flowing gas that may contain solid or liquid particulate matter. The stream comprises gaseous components and may be, for example, exhaust from a lean-burn engine, which may contain certain non-gaseous components such as liquid droplets, solid particulates, and the like. The exhaust gas stream from a combustion engine may also comprise combustion products (CO2 and H2O), products of incomplete combustion (carbon monoxide (CO) and Petition 870240108964, dated 12 / 20 / 2024, page 27 / 87 17 / 66 hydrocarbons (HC), nitrogen oxides (NOx), fuel and / or carbonaceous particulate matter (soot), and unreacted oxygen and nitrogen. As used in this document, the terms “upstream” and “downstream” refer to relative directions according to the flow of an exhaust gas stream from an engine towards an exhaust pipe, with the engine at an upstream location and the exhaust pipe and any pollution abatement devices, such as filters and catalysts, being downstream of the engine. The inlet end of a substrate is synonymous with the “upstream” or “front” end. The outlet end is synonymous with the “downstream” or “rear” end. An upstream zone is upstream of a downstream zone. An upstream zone may be closer to the engine or manifold, and a downstream zone may be farther from the engine or manifold.

[0055] The term “in fluid communication” is used to refer to articles positioned on the same exhaust line, for example, a common exhaust stream passes through articles that are in fluid communication with each other. Articles in fluid communication may be adjacent to each other on the exhaust line. Alternatively, articles in fluid communication may be separated by one or more articles, also called “washcoat-coated monoliths”.

[0056] The term “functional article” in the disclosure means an article comprising a substrate having a functional coating composition disposed thereon, such as a catalyst and / or a sorbent coating composition.

[0057] As used in this document, “impregnated” or “impregnation” refers to the permeation of the catalytic material into the porous structure of the support material.

[0058] As used in this document, “lean gas stream” includes lean exhaust streams and refers to gas streams that Petition 870240108964, dated 12 / 20 / 2024, p. 28 / 87 18 / 66 have a λ > 1.0, where λ refers to the air / fuel ratio.

[0059] As used in this document, “poor period” refers to a period of exhaust treatment in which the exhaust gas composition is poor, for example, it has a λ > 1.0.

[0060] The terms “on” and “above” in reference to a coating layer may be used synonymously. The term “directly on” means direct contact with. The disclosed articles are referred to in certain embodiments as comprising a coating layer “on” a second coating layer and such language is intended to encompass embodiments with intervening layers where direct contact between the coating layers is not required (e.g., “on” is not equated with “directly on”).

[0061] As used in this document, the term “promoter” refers to a component that is intentionally added to the rare earth metal component, as opposed to impurities inherent in the rare earth metal component. “Promoters” are metals that increase activity toward a desired chemical reaction or function.

[0062] As used in this document, “rich gas stream” includes rich exhaust streams and refers to gas streams that have a λ < 1.0.

[0063] As used in this document, “rich period” refers to a period of exhaust treatment in which the exhaust gas composition is rich, for example, it has a λ < 1.0.

[0064] As used herein, the term “selective catalytic reduction” (SCR) refers to the catalytic process of reducing nitrogen oxides to dinitrogen (N2) using a nitrogenous reductant.

[0065] As used in this document, the terms “nitrogen oxides” or “NOx” refer to nitrogen oxides, such as NO, NO2 or Petition 870240108964, dated 12 / 20 / 2024, page 29 / 87 19 / 66 N2O.

[0066] As used in this document, the term “stream” refers broadly to any combination of flowing gas that may contain solid or liquid particulate matter. The term “gas stream” or “exhaust gas stream” means a stream of gaseous constituents, such as the exhaust from a combustion engine, which may contain entrained non-gaseous components, such as liquid droplets, solid particulates and the like. The exhaust gas stream from a combustion engine may further comprise combustion products (CO2 and H2O), products of incomplete combustion (carbon monoxide (CO) and hydrocarbons (HC)), nitrogen oxides (NOx), fuel and / or carbonaceous particulate matter (soot) and unreacted oxygen and nitrogen.

[0067] As used in this document, the term “substantially free” means “little or none” or “not intentionally added” and also having only traces and / or inadvertent amounts. For example, in certain embodiments, “substantially free” means less than 2% by weight (% by weight), less than 1.5% by weight, less than 1.0% by weight, less than 0.5% by weight, 0.25% by weight or less than 0.01% by weight, based on the weight of the stated total composition.

[0068] As used in this document, the term “substrate” refers to the monolithic material onto which the catalyst composition, i.e., catalytic coating, is applied, for example in the form of a washcoat. In one or more embodiments, the substrates are continuous flow monoliths and monolithic wall flow filters. Continuous flow and wall flow substrates are also taught, for example, in International Application Publication WO2016 / 070090, which is incorporated herein by reference. A washcoat is formed by preparing a flowable paste containing a specified solids content (e.g., 30% to 90% by weight). Petition 870240108964, dated 12 / 20 / 2024, page 30 / 87 20 / 66 of catalyst in a liquid that is then coated onto a substrate and dried to provide a washcoat layer. The reference to “monolithic substrate” means a unitary structure that is homogeneous and continuous from inlet to outlet. A washcoat is formed by preparing a fluid paste containing a certain solids content (e.g., 20% to 90% by weight) of particles in a liquid vehicle that is then coated onto a substrate and dried to provide a washcoat layer.

[0069] As used in this document, the terms “upstream” and “downstream” refer to relative directions according to the flow of an exhaust gas stream from an engine towards an exhaust pipe, with the engine at an upstream location and the exhaust pipe and any pollution abatement devices, such as filters and catalytic converters, being downstream of the engine.

[0070] As used herein, the term “washcoat” has its usual meaning in the art of a thin, adherent coating of a catalytic or other material applied to a substrate material, such as a honeycomb-type substrate, that is sufficiently porous to allow the passage of the gas stream being treated. As used in this document and described in Heck, Ronald and Farrauto, Robert, Catalytic Air Pollution Control, New York: Wiley-Interscience, 2002, pp. 18–19, a washcoat layer includes a compositionally distinct layer of material disposed on the surface of a monolithic substrate or an underlying washcoat layer. A substrate may contain one or more washcoat layers, and each washcoat layer may be different in some way (e.g., it may differ in physical properties such as particle size or crystallite phase) and / or may differ in chemical catalytic functions.

[0071] “Percent by weight (% by weight)”, unless otherwise indicated, is based on a whole composition free of any volatiles, i.e., Petition 870240108964, dated 12 / 20 / 2024, page 31 / 87 21 / 66 based on dry solids content. Unless otherwise indicated, all parts and percentages are by weight.

[0072] All methods described in this document may be performed in any appropriate order unless otherwise indicated in this document or otherwise clearly contradicted by the context. The use of any and all examples or exemplary language (e.g., “how”) provided in this document is intended only to better clarify the materials and methods and does not represent a limitation on scope unless otherwise indicated. No language in the descriptive report should be interpreted as indicating any unclaimed element as essential to the practice of the materials and methods disclosed. All US patent applications, pre-grant publications and patents referenced herein are incorporated herein by reference in their entirety.

[0073] In some embodiments, an emission treatment system is provided for reducing NOx in an exhaust stream from a lean-burning engine. The emission treatment system comprises a lean NOx scavenger (LNT) comprising an oxygen storage component (OSC) and a first platinum group metal (PGM) component, wherein the LNT is in fluid communication with and downstream of the lean-burning engine. The emission treatment system further comprises a low-temperature NOx adsorber (LT-NA) comprising a molecular sieve comprising a second platinum group metal (PGM) component, wherein the LT-NA is in fluid communication with and downstream of the LNT. The LNT and LT-NA, as well as other components of the emission treatment system, are disclosed in more detail below. Low NOx Pickup (Lnt)

[0074] As disclosed in this document, some Petition 870240108964, dated 12 / 20 / 2024, page 32 / 87 22 / 66 embodiments of emission treatment systems comprise an LNT. In principle, the LNT can be any LNT known in the art. In some embodiments, the LNT is similar to one disclosed in U.S. Patent Application Publication No. 20090320457 to Wan, which is incorporated herein by reference in its entirety. In some embodiments, the LNT comprises an oxygen storage component (OSC) and a first platinum group metal (PGM) component. The OSC and the first PGM component are described in more detail below. Oxygen Storage Component (OSC)

[0075] As used in this document, OSC refers to an entity that has multivalent oxidation states and that can actively react with oxidants such as oxygen (O2) or nitrogen oxides (NOx) under oxidizing conditions, or react with reductants such as carbon monoxide (CO), hydrocarbons (HC), or hydrogen (H2) under reducing conditions. For example, cerium (Ce) in ceria (CeO2), (e.g., with a valence state of Ce+4), when subjected to reducing conditions, may contain a portion of the Ce atoms in the valence state Ce+3.

[0076] Some example embodiments of CSOs include rare earth metal oxides, which refer to one or more oxides chosen from scandium (Sc), yttrium (Y), and the lanthanide series as defined in the Periodic Table of Elements and combinations thereof. In some embodiments, the CSO includes a single rare earth metal oxide (e.g., 100 percent by weight). In some embodiments, the CSO may comprise a mixture of several rare earth metal oxides. For example, ceria may be delivered as a mixed oxide of cerium (Ce) and zirconium (Zr) and / or a mixed oxide of cerium (Ce), zirconium (Zr), and neodymium (Nd). For example, praseodymium can be supplied as a mixed oxide of praseodymium (Pr) and zirconium (Zr) and / or a mixed oxide of praseodymium (Pr), cerium (Ce), lanthanum (La), yttrium (Y), zirconium (Zr) and Petition 870240108964, dated 12 / 20 / 2024, page 33 / 87 23 / 66 neodymium (Nd). In some embodiments, the OSC comprises one or more selected from ceria, zirconia, alumina, silica, titania, lantana, barium, praseodymium, yttria, samaria, gadolinium, and combinations thereof. In some embodiments, the OSC comprises ceria. In some embodiments, the OSC comprises ceria and one or more additional rare earth metal oxides. First Platinum Group Metal (PGM)

[0077] The LNT, as disclosed in this document, comprises a first platinum group metal (PGM) component in combination with the OSC. The first PGM plays the role of catalytic oxidation and reduction of NOx. The term “PGM component” refers to any component that includes a PGM, which may include one or more chosen from ruthenium (Ru), rhodium (Rh), osmium (Os), iridium (Ir), palladium (Pd), platinum (Pt), gold (Au), and combinations thereof. Reference to “PGM component” allows for the presence of the PGM in any valence state. For example, the PGM may be in metallic form, with zero valence, or the PGM may be in an oxide form.The terms “platinum (Pt) component”, “rhodium (Rh) component”, “palladium (Pd) component”, “iridium (Ir) component”, “ruthenium (Ru) component” and the like refer to the respective platinum group metal compound, complex or similar which, upon calcination or use of a catalyst, decomposes or otherwise converts into a catalytically active form, generally the metal or metal oxide. In some embodiments, the first component of PGM comprises one or more selected from palladium, platinum, rhodium, rhenium, ruthenium, iridium and combinations thereof. In some embodiments, the first component of PGM comprises palladium, platinum or a mixture thereof. In some embodiments, the first component of PGM comprises two platinum group metals, for example, in a weight ratio of about 1:10 to about 10:1. For example, in some modalities, the first PGM component comprises platinum and... Petition 870240108964, dated 12 / 20 / 2024, p. 34 / 87 24 / 66 palladium. In some embodiments, the first PGM component includes a platinum group metal. For example, the first PGM component is palladium. In another example, the first PGM component is platinum.

[0078] The first PGM component may be present in the LNT in an amount in the range of about 0.01% to about 5% or about 0.1% to about 3% by weight on a metal base. In some embodiments, the first PGM is present in a range of about 0.5% to about 2.5% by weight (e.g., about 2% by weight) in the LNT. NOx Adsorbent Component

[0079] In some embodiments, the LNT further comprises a NOx-adsorbent component, for example, chosen from an alkali metal component, an alkaline earth metal component, and combinations thereof. In some embodiments, the NOx-adsorbent component comprises an alkali metal component. As used herein, the term “alkali metal component” refers to one or more chemical elements chosen from Group I of the Periodic Table of Elements, for example, in the form of an oxide, hydroxide, or carbonate. In some embodiments, the alkali metal is chosen from potassium (K), sodium (Na), lithium (Li), cesium (Cs), and combinations of two or more thereof. The alkali metal component may be present in the LNT in an amount of about 1% to about 30%, about 1% to about 20%, or about 5% to about 10% by weight of the LNT on an oxide basis.

[0080] In some embodiments, the LNT further comprises an alkaline earth metal component. As used herein, the term “alkaline earth metal component” refers to one or more elements selected from Group II of the Periodic Table of Elements, including beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), and barium (Ba), for example, in the form of an oxide, hydroxide, or carbonate. In some embodiments, the Petition 870240108964, dated 12 / 20 / 2024, page 35 / 87 25 / 66 The alkaline earth metal component may be incorporated into the NOx adsorbent component as a salt and / or oxide (e.g., BaCOa). In one or more embodiments, the alkaline earth metal component comprises barium. The alkaline earth metal component may be present in the LNT in an amount of about 1% to about 30%, about 1% to about 20%, or about 5% to about 10% by weight of the LNT on an oxide basis.

[0081] For additional examples of NOx adsorbent components, see U.S. Patents Nos. 5,750,082 to Hephurn et al.; 8,105,559 to Melville et al.; 8,475,752 to Wan et al.; 8,592,337 to Holgendorff et al.; 9,114,385 to Briskley et al.; 9,486,791 to Swallow et al.; 9,610,564 to Xue et al.; 9,662,611 to Wan et al.; U.S. Patent Application Publication Nos. 2002 / 0077247 to Bender et al.; 2011 / 0305615 to Hilgendorff et al.; 2015 / 0157982 to Rajaram et al.; 2015 / 0158019 for Rajaram et al.; 2016 / 0228852 for Biberger et al.; and International Patent Application WO 2016 / 141142 for Grubert et al., each of which is incorporated by reference in its entirety. Support

[0082] The OSC and the first PGM component may optionally be supported (disposed or impregnated) in a support material. For example, the PGM component may be supported in any suitable material. In some embodiments, the support material is a metal oxide support. As used herein, “metal oxide support” refers to metal-containing oxide materials exhibiting chemical and physical stability at high temperatures, such as the temperatures associated with diesel engine exhaust. Exemplary metal oxides include, but are not limited to, ceria, alumina, silica, zirconia, titania, or combinations thereof. For example, in some embodiments, metal oxides such as alumina, silica, zirconia, or titania may be combined as physical mixtures or chemical combinations with ceria to form the metal oxide support. Petition 870240108964, dated 12 / 20 / 2024, page 36 / 87 26 / 66

[0083] In some embodiments, the metal oxide support comprises atomically doped combinations of metal oxides. For example, in some embodiments, the metal oxide support is modified to contain a dopant metal in oxide form, such as, but not limited to, a lanthanide group metal or metals selected from La, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Si, Nb, Zr and combinations thereof. In some embodiments, the dopant metal is chosen from Pr, Gd, Zr and combinations thereof. In some embodiments, the total amount of dopant metal or combination thereof varies from about 0.1% to about 15% by weight based on the total weight of the LNT composition.In some embodiments, the metal oxides include, but are not limited to, mixtures of two or more metal oxides chosen from alumina-zirconia, ceria-zirconia, alumina-ceria-zirconia, lanthana-alumina, lanthana-zirconia-alumina, baria-alumina, baria-lantana-alumina, baria-lantana-neodymium-alumina, alumina-ceria, and combinations thereof. In some embodiments, the aluminas include large-pore boehmite, gamma-alumina, delta / theta alumina, and combinations thereof. In some embodiments, useful commercial aluminas used include activated aluminas, such as high-density bulk gamma-alumina, low- or medium-density bulk large-pore gamma-alumina, low-density bulk large-pore boehmite, gamma-alumina, and combinations thereof. In some embodiments, when alumina is doped, the total amount of dopant is in a range of about 0.25% to 5% by weight, such as in a range of about 0.5% to 3% by weight (e.g., about 1% by weight) of alumina.In some modalities, no supporting material is present (for example, LNT does not include supporting material).

[0084] Although the previous description provides several suitable ranges or amounts for the first component of PGM, alkali metal, Petition 870240108964, dated 12 / 20 / 2024, page 37 / 87 27 / 66 alkaline earth metal, OSC and LNT support components, it should be noted that each range or quantity disclosed for one of these components may be combined with a range or quantity disclosed for the other components to form new ranges or sub-ranges. Such embodiments are also expressly contemplated and covered by the scope of the disclosure. Low Temperature NOx Adsorbent (Lt-Na)

[0085] An LT-NA as disclosed herein comprises a molecular sieve comprising a second platinum group metal (PGM) component. The molecular sieve and the second PGM component are described in more detail below. Molecular Sieve

[0086] As used in this document, the term “molecular sieve”, such as zeolite and other zeolitic framework material (e.g., isomorphically substituted material), refers to materials based on an extensive three-dimensional network of oxygen ions generally containing tetrahedral-type sites and having a substantially uniform pore distribution, with the average pore size not being larger than about 0.2 nm (nanometers) (20 Angstroms (Å)).

[0087] Molecular sieves can be differentiated primarily according to the geometry of the voids formed by the rigid lattice of SiO4 / AlO4 tetrahedra. The entrances to the voids are formed by 6, 8, 10, or 12 ring atoms relative to the atoms forming the entrance opening. Molecular sieves are crystalline materials that have fairly uniform pore sizes which, depending on the type of molecular sieve and the types and quantities of cations included in the molecular sieve lattice, range from about 0.3 nm to about 0.1 nm (3 Å to about 10 Å) in diameter. The phrase "8-ring molecular sieve" refers to a molecular sieve that has pore openings of 8 Petition 870240108964, dated 12 / 20 / 2024, p. 38 / 87 28 / 66 rings and secondary building units of six double rings that have a cage-like structure resulting from the connection of six double ring building units by 4 rings. Molecular sieves comprise molecular sieves with small, medium, large pores or combinations thereof. Pore sizes are defined by ring size.

[0088] A small pore molecular sieve contains channels defined by up to eight tetrahedral atoms. As used in this document, the term “small pore” refers to pore openings that are smaller than about 0.5 nm (nanometers) (5 Å (angstroms)), for example, on the order of about 0.38 nm (3.8 Å). In some embodiments, exemplary small-pore molecular sieves include frame types selected from 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.

[0089] A medium-pore molecular sieve contains channels defined by ten-membered rings. In some embodiments, exemplary medium-pore molecular sieves include frame types chosen from 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, SFG, STF, STI, STT, STW, SVR, SZR, TER, TON, TUN, UOS, VSV, WEI, WEN and mixtures or intergrowths thereof.

[0090] A large-pore molecular sieve contains channels defined by twelve-membered rings. In some embodiments, exemplary large-pore molecular sieves include frame types chosen from 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, Petition 870240108964, dated 12 / 20 / 2024, p. 39 / 87 29 / 66 IWS, IWV, IWW, JSR, LTF, LTL, MAZ, MEI, MOR, MOZ, MSE, MTW, NPO, OFF, OKO, OSI, RON, RWY, SAF, SAO, SBE, SBS, SBT, SEW, SFE, SFO, SFS, SFV, SOF, SOS, SOS, SSO, USFET, USFET, USFET, USFET, VET mixtures or intergrowths of the same.

[0091] In some embodiments, any type of molecular sieve framing can be used, such as framing types chosen from ABW, ACO, AEI, AEL, AEN, AET, AFG, AFI, AFN, AFO, AFR, AFS, AFT, AFY, AHT, APT, APT, APTNA AST, ASV, ATN, ATO, ATS, ATT, ATV, AVL, AWO, AWW, BCT, BEA, BEC, BIK, BOG, BPH, BRE, CAN, CAS, SCO, CFI, SGF, CGS, CHA, CHI, CLO, CON, CZP, DAC, DDR, DOH, DOH, EDI, EDI, EDI EMT, EON, EPI, ERI, ESV, ETR, EUO, FAU, FER, FRA, GIS, GIU, GME, GON, GOO, HEU, IFR, IFY, IHW, IRN, ISV, ITE, ITH, ITW, IWR, IWW, JBW, KFI, LAU, LEV, LIO, LIT, LIT, LOS, LOS, LOS LTN, MAR, MAZ, MAY, MEL, MEP, MER, MFI, MFS, MON, MOR, MOZ, MSO, MTF, MTN, MTT, MTW, MWF, MWW, NAB, NAT, NES, NON, NPO, NPT, NSI, OBW, OFF, OSI, OSO, PAR, PHO, PHO, PHO, PHO, PHO RON, RRO, RSN, RTE, RTH, RUT, RWR, RWY, SAO, SAS, SAT, SAV, SBE, SBS, SBT, SFE, SFF, SFG, SFH, SFN, SFO, SFW, SGT, SOD, SOS, SSY, STF, STI, STT, TER, TON, THO, USC, USC, USC USI, UTL, VET, VFI, VNI, VSV, HOW, WHEN,YUG, ZON, and combinations thereof.

[0092] For example, a present molecular sieve may comprise a frame type selected from the group consisting of AEI, BEA (beta zeolites), CHA (chabazite), FAU (zeolite Y), FER (ferrierite), MFI (ZSM-5) and MOR (mordenite). In some embodiments, the molecular sieve has a frame type selected from AFX, CHA and FER.

[0093] As used in this document, the term “zeolite” refers to a specific example of a molecular sieve that also includes silicon and aluminum atoms. Generally, molecular sieves, for example, zeolites, are defined as aluminosilicates with three-dimensional structures. Petition 870240108964, dated 12 / 20 / 2024, p. 40 / 87 30 / 66 open frameworks composed of TO4 tetrahedra sharing corners, where T is Al or Si, or optionally P. Charge-balancing cations of the anionic framework are weakly associated with framework oxygens, and the remaining pore volume is filled with water molecules. Non-framework cations are generally interchangeable, and water molecules are removable. In some embodiments, aluminosilicate zeolite structures do not include phosphorus or other isomorphically substituted metals in the framework. That is, “aluminosilicate zeolite” may not include aluminophosphate materials such as SAPO, AlPO, and MeAlPO materials. In some embodiments, the broader term “zeolite” includes aluminosilicates and aluminophosphates. For the purposes of this disclosure, SAPO, AlPO, and MeAlPO materials are considered non-zeolitic molecular sieves.

[0094] A zeolite may comprise SiO4 / AlO4 tetrahedra that are linked by common oxygen atoms to form a three-dimensional network. The molar ratio of silica to alumina (“SAR”) of a present zeolite may vary over a wide range, but is generally 2 or greater. For example, a present zeolite may have a SAR of about 5 to about 1,000.

[0095] Non-limiting examples of molecular sieves having the structures AEI, BEA, CHA, FAU, FER, MFI, and MOR include chabazite, faujasite, zeolite Y, ultrastable zeolite Y, beta zeolite, mordenite, silicalite, zeolite X, and ZSM-5. In some embodiments, the molecular sieve is chosen from Type A, beta zeolite, chabazite, erionite, faujasite, ferrierite, mordenite, silicalite, SSZ-13, stilbite, ZSM-5, ZSM-11, ZSM-23, ZSM-48, zeolite X, and zeolite Y. Second Platinum Group Metal (PGM)

[0096] The LT-NA as disclosed herein comprises a molecular sieve substituted with a second PGM component (e.g., the molecular sieve is a molecular sieve substituted with a PGM component). As used herein, the term Petition 870240108964, dated 12 / 20 / 2024, page 41 / 87 31 / 66 “replaced by PGM” encompasses the term “ion exchange.” As used herein, “ion exchanged” or “PGM exchanged” means that a PGM is supported on or within a molecular sieve material. In some embodiments, at least part of the PGM is in ionic form. In some embodiments, a portion of the PGM may be in zero-valence metallic form or may be in the form of metal oxide aggregates. In some embodiments, the disclosed LT-NA is described as comprising a molecular sieve “comprising” a second PGM component (or comprising a second PGM component “associated” with the molecular sieve). In such cases, “comprising” (or “associated with”) is understood to mean that the second PGM component resides either in the ion exchange sites of the molecular sieve, on the surface of the molecular sieve, or both in the ion exchange sites and on the surface of the molecular sieve.In some embodiments, the disclosed LT-NA can be described as comprising a molecular sieve “containing” a second PGM, and in such cases, “containing” means that the PGM resides in the ion exchange sites of the sieve or on the surface, or both.

[0097] With regard to the term “second PGM component”, the term “PGM component” has the same meaning as described above for the first PGM component. The second PGM component may be the same as or different from the first PGM component. In some embodiments, the LT-NA as disclosed herein comprises a molecular sieve comprising a second PGM component, wherein the second PGM component is the same as the first PGM component. In some embodiments, the LT-NA as disclosed herein comprises a molecular sieve substituted for a second PGM component, wherein the second PGM component is different from the first PGM component. Petition 870240108964, dated 12 / 20 / 2024, page 42 / 87 32 / 66

[0098] In some embodiments, the second PGM component comprises one or more metals chosen from palladium, platinum, rhodium, rhenium, ruthenium, iridium, and combinations thereof. In some embodiments, the second PGM component comprises one or more metals chosen from platinum, palladium, rhodium, and combinations thereof. In some embodiments, the second PGM component comprises one or more metals chosen from palladium, platinum, and mixtures thereof. In some embodiments, the second PGM component comprises two platinum group metals, for example, in a weight ratio of about 1:10 to about 10:1. For example, in some embodiments, the second PGM component comprises platinum and palladium. In some embodiments, the second PGM component comprises a platinum group metal, such as palladium.

[0099] The concentration of the second PGM component may vary, for example, from about 0.01% by weight to about 6% by weight relative to the total weight of the molecular sieve. The second PGM component may be present in the molecular sieve, for example, from about 0.1% by weight, about 0.2% by weight, about 0.5% by weight, about 0.7% by weight, about 0.9% by weight or about 1.0% by weight, to about 1.5% by weight, about 2.0% by weight, about 2.5% by weight, about 3.0% by weight, about 3.5% by weight, about 4.0% by weight, about 4.5% by weight, about 5.0% by weight, or about 6% by weight, based on the total dry weight of the molecular sieve. The weights of the second component of PGM are measured and reported as the metal (e.g., weight of palladium). The total dry weight of the molecular sieve includes any added / exchanged metals (e.g., palladium).

[0100] In some embodiments, the LT-NA molecular sieve as disclosed herein has at least about 1% by weight of the amount of PGM located within the pores of the molecular sieve, for example, at least about 5% by weight, at least about 10% by weight. Petition 870240108964, dated 12 / 20 / 2024, page 43 / 87 33 / 66 weight, at least about 25% by weight, or at least about 50% by weight of the PGM located within the pores of the molecular sieve.

[0101] In some embodiments, the molecular sieve of LT-NA as disclosed in this document may be replaced by a metal, for example, a base metal. Thus, the molecular sieve of LT-NA may comprise a molecular sieve, a second PGM component and, optionally, a base metal. The molecular sieve may contain the second PGM component and, optionally, the base metal. The base metal may be chosen from iron (Fe), copper (Cu), manganese (Mn), chromium (Cr), cobalt (Co), nickel (Ni), zinc (Zn), tin (Sn) and mixtures of two or more thereof. In some embodiments, the base metal is chosen from Fe, Cu, Co and mixtures thereof. In some embodiments, the molecular sieve may be substantially free of a base metal. In some embodiments, the molecular sieve does not comprise a base metal. In some embodiments, the LT-NA is substantially free of any other active metal besides the second PGM component. Preparation of LNT and LT-NA Compositions

[0102] The LNTs and LT-NAs as disclosed in this document can be readily prepared by processes known in the art. The disclosed LNTs and / or LT-NAs can, in some embodiments, be prepared by means of an incipient moisture impregnation method. Incipient moisture impregnation techniques, also called capillary impregnation or dry impregnation, are used for the synthesis of heterogeneous materials, for example, catalysts. For example, 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 rare earth metal oxide or molecular sieve) and which contains the same pore volume as the volume of the solution that Petition 870240108964, dated 12 / 20 / 2024, page 44 / 87 34 / 66 was added. Capillary action draws the solution into the pores of the material. The solution added in excess of the material's pore volume causes the solution transport to change from a capillary action process to a diffusion process, which is much slower. The impregnated material can then be dried and calcined to remove volatile components within the solution, depositing the metal on the material's surface. The maximum loading is limited by the solubility of the precursor in the solution. The concentration profile of the impregnated material depends on the mass transfer conditions within the pores during impregnation and drying. One skilled in the art will recognize other methods for loading PGM components into, for example, the OSC and molecular sieve of the present LNT and LT-NA compositions, for example, by adsorption.

[0103] For example, in the preparation of LT-NA, the second PGM component can be added to the molecular sieve by any suitable means, and the mode of addition may not be critical. For example, a PGM component precursor (such as, for example, palladium nitrate) and optionally a base metal compound can be supported on the molecular sieve by impregnation, adsorption, ion exchange, incipient moisture, precipitation, or the like. In some embodiments, non-limiting examples of suitable PGM component precursors include palladium nitrate, tetra-amine palladium nitrate, tetra-amine platinum acetate, platinum nitrate, and combinations thereof. During the calcination steps, or at least during the initial phase of catalyst use, such compounds are converted into a catalytically active form of the metal or a compound thereof. Catalytic Articles

[0104] In one or more embodiments, the LNT and LT-NA, as disclosed in this document, are arranged (coated) in one or more Petition 870240108964, dated 12 / 20 / 2024, p. 45 / 87 35 / 66 substrates, as described below. In some embodiments, LNT and LT-NA are provided on one or more substrates in the form of one or more coatings. A substrate coated with LNT and / or LT-NA is referred to as a catalyst article. Catalyst articles are part of an exhaust gas treatment system (e.g., catalyst articles including, but not limited to, articles that include LNT and LNT-NA as disclosed in this document). The individual components comprising such LNT and LT-NA items are described in detail below (e.g., including substrate (or substrates), coating (or coatings), and coating configurations according to certain embodiments). Substrates

[0105] In some embodiments, substrates are three-dimensional, having a length, diameter, and volume similar to a cylinder. In some embodiments, the shape does not necessarily have to conform to a cylinder. The length of the substrate is an axial length defined by an inlet end and an outlet end.

[0106] According to one or more embodiments, the substrate for the disclosed LNT and / or LT-NA article(s) may be constructed of any material that can be used to prepare automotive catalysts and, for example, comprises a honeycomb structure of metal or ceramic. In some embodiments, the substrate provides a plurality of wall surfaces on which the coating comprising the LNT and / or LT-NA is applied and adhered, thereby acting as a substrate for the catalyst composition.

[0107] In some embodiments, the substrates are ceramic substrates that can be made of any suitable refractory material, for example, cordierite, cordierite-alumina, aluminum titanate, silicon titanate, Petition 870240108964, dated 12 / 20 / 2024, page 46 / 87 36 / 66 silicon carbide, silicon nitride, mullite zirconium, spodumene, alumina-silica-magnesia, zirconium silicate, sillimanite, a magnesium silicate, zirconium, petalite, α-alumina, an aluminosilicate and / or the like.

[0108] In some embodiments, the substrates are metallic, comprising one or more metals or metal alloys. In some embodiments, a metallic substrate may include suitable types, such as those with openings or “punctures” in the channel walls. Metallic substrates may be employed in various forms, such as pellets, corrugated sheet, or monolithic foam. Examples of metallic substrates include heat-resistant metal-based alloys, such as those in which iron is a major or substantial component. For example, these alloys may contain one or more chosen from nickel, chromium, and aluminum, and the total of these metals may comprise at least about 15% by weight (percent by weight) of the alloy. For example, a metallic substrate may include about 10% by weight to about 25% by weight of chromium, about 1% by weight to about 8% by weight of aluminum, and from 0% to about 20% by weight of nickel, in each case based on the weight of the substrate.In some embodiments, the metallic substrates have straight channels. In some embodiments, the metallic substrates have protruding blades along the axial channels to interrupt gas flow and open gas flow communication between the channels. In some embodiments, the metallic substrates have blades and also holes to improve gas transport between the channels, allowing radial gas transport throughout the monolith. Metallic substrates, for example, employed in certain embodiments in a close coupling position, allow rapid heating of the substrate and, correspondingly, rapid heating of a catalyst composition coated on it (e.g., an LNT and / or LT-NA catalyst composition).

[0109] Any suitable substrate for catalytic articles Petition 870240108964, dated 12 / 20 / 2024, p. 47 / 87 37 / 66 disclosed in this document may be employed, such as a monolithic substrate of the type having thin parallel gas flow passages extending through it from an inlet or outlet face of the substrate, such that passages are open for fluid flow through them (“continuous flow substrate”). Another suitable substrate is of the type having a plurality of substantially parallel and thin gas flow passages extending along the longitudinal axis of the substrate wherein, typically, each passage is blocked at one end of the substrate body, with alternating blocked passages at opposite end faces (“wall flow filter”). Continuous flow and wall flow substrates are also taught, for example, in International Application Publication WO2016 / 070090, which is incorporated herein by reference in its entirety.

[0110] In some embodiments, the LNT is placed on a first substrate and the LT-NA is placed on a second substrate. In some embodiments, the first substrate is a honeycomb substrate in the form of a continuous flow filter and the second substrate is a honeycomb substrate in the form of a continuous flow filter or a wall flow filter. In some embodiments, the LNT and the LT-NA are both placed on the same substrate. In some embodiments, the substrate comprises a honeycomb substrate in the form of a continuous flow filter. Continuous flow filters and wall flow filters will be discussed in more detail in this document below. Continuous Flow Filter Substrates

[0111] In some embodiments, the substrate is a continuous flow filter (for example, a monolithic continuous flow filter substrate, including a monolithic continuous flow alveolar filter substrate). Continuous flow filter substrates have parallel, thin gas flow passages extending from an inlet end to an outlet end of the substrate, so that the passages are open to the flow of Petition 870240108964, dated 12 / 20 / 2024, page 48 / 87 38 / 66 fluid. The passages, which are essentially straight paths from their fluid inlet to their fluid outlet, are defined by walls in which a catalytic coating is disposed, so that gases flowing through the passages contact the catalytic material. The flow passages of the continuous flow filter substrate are thin-walled channels, which can have any suitable size and cross-sectional shape, such as trapezoidal, rectangular, square, sinusoidal, hexagonal, oval, circular, etc. The continuous flow filter substrate can be ceramic or metallic, as described above.

[0112] Continuous flow filter substrates may, for example, have a volume in a range of about 819.35 cm3 to about 19,664.48 cm3 (about 50 in3 to about 1,200 in3), a cell density (e.g., inlet openings) in a range of about 9.29 cells per square centimeter (60 cells per square inch (cpsi)) to about 77.49 cells per square centimeter (500 cpsi) or up to about 139.49 cells per square centimeter (900 cpsi), for example, from about 30.99 to about 61.99 cells per square centimeter (about 200 cpsi to about 400 cpsi) and a wall thickness in a range of about 50 microns to about 200 microns or about 400 microns.

[0113] A catalytic article can be provided by applying a catalytic coating (for example, as disclosed in this document) to the substrate as a washcoat. Figures 1A and 1B illustrate an example substrate (2) in the form of a continuous flow filter substrate coated with a catalyst composition as described in this document. With reference to Figure 1A, the example substrate (2) has a cylindrical shape and a cylindrical outer surface (4), an upstream end face (6) and a corresponding downstream end face (8) which is identical to the end face (6). The substrate (2) has a plurality of thin parallel gas flow passages (10) formed in Petition 870240108964, dated 12 / 20 / 2024, page 49 / 87 39 / 66 same. As seen in Figure 1B, the flow 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), the passages (10) being unobstructed so as to allow the flow of a fluid, for example, a gas stream, longitudinally through the carrier (2) by means of gas flow passages (10) thereof. As more easily seen in Figure 1B, the walls (12) are thus dimensioned and configured that the gas flow passages (10) have a substantially regular polygonal shape. As shown, the catalyst composition can be applied in multiple distinct layers if desired. In the illustrated embodiment, the catalyst composition consists of both a discrete lower layer (14) adhered to the walls (12) of the carrier member and a second discrete upper layer (16) coated over the lower layer (14).The present disclosure can be implemented with one or more (e.g., two, three, or four or more) layers of catalyst composition and is not limited to the two-layer embodiment illustrated in Figure 1B. Other coating configurations are disclosed in this document below. Wall Flow Filter Substrates

[0114] In some embodiments, the substrate is a wall-mounted flow filter, which generally has a plurality of thin, substantially parallel gas flow passages extending along the longitudinal axis of the substrate. In some embodiments, each passage is blocked at one end of the substrate body, with alternating passages blocked at opposite end faces. Such monolithic wall-mounted flow filter substrates may contain up to about 139.49 (900) or more flow passages (or “cells”) per square centimeter (per square inch) of cross-section, although far fewer may be used. For example, the substrate may have from about 1.08 to about 92.99 (7 ​​to about 600), more generally Petition 870240108964, dated 12 / 20 / 2024, page 50 / 87 40 / 66 of approximately 15.49 to approximately 61.99 cells per square centimeter (cm2) (100 to approximately 400 cells per square inch (“cpsi”)). The cells may have cross-sections that are rectangular, square, circular, oval, triangular, hexagonal, or other polygonal shapes.

[0115] Figure 2 is a perspective view of an example wall flow filter. A cross-sectional view of a monolithic wall flow filter substrate section is illustrated in Figure 2, showing alternating obstructed and open passages (cells). The blocked or obstructed ends (100) alternate with the open passages (101), with each opposite end open and blocked, respectively. The filter has an inlet end (102) and an outlet end (103). Arrows crossing porous cell walls (104) represent exhaust gas flow entering the open cell ends, diffusion through the porous cell walls (104), and exiting the open outlet cell ends. Obstructed ends (100) impede gas flow and encourage diffusion through the cell walls. Each cell wall has an inlet side (104a) and an outlet side (104b). The passages are delimited by the cell walls.

[0116] The wall flow filter article substrate may have a volume of, for example, about 50 cm3, about 100 cm3, about 200 cm3, about 300 cm3, about 400 cm3, about 500 cm3, about 600 cm3, about 700 cm3, about 800 cm3, about 900 cm3, or about 1,000 cm3 to about 1,500 cm3, about 2,000 cm3, about 2,500 cm3, about 3,000 cm3, about 3,500 cm3, about 4,000 cm3, about 4,500 cm3, or about 5,000 cm3. Wall-flow filter substrates can have a wall thickness of about 50 microns to about 2,000 microns, for example, from about 50 microns to about 450 microns or from about 150 microns to about 400 microns. Petition 870240108964, dated 12 / 20 / 2024, p. 51 / 87 41 / 66

[0117] The walls of the wall-flow filter are porous and may have a wall porosity of at least about 50% or at least about 60% with an average pore size of at least about 5 microns before the application of the functional coating. For example, the substrate of the wall-flow filter article in some embodiments may have a porosity of > 50%, > 60%, > 65% or > 70%. For example, the wall-flow filter article substrate will have a wall porosity of about 50%, about 60%, about 65%, or about 70% to about 75%, about 80%, or about 85% and an average pore size of about 5 microns, about 10 microns, about 20 microns, about 30 microns, about 40 microns, or about 50 microns to about 60 microns, about 70 microns, about 80 microns, about 90 microns, or about 100 microns before the arrangement of a catalytic coating.The terms “wall porosity” and “substrate porosity” mean the same thing and are interchangeable. Porosity is the ratio of void volume divided by the total volume of a substrate. Pore size can be determined according to the ISO15901-2 procedure (e.g., static volumetric) for nitrogen pore size analysis. Nitrogen pore size can be determined using Micromeritics TRISTAR 3000 series instruments. Nitrogen pore size can be determined using BJH (Barrett-Joyner-Halenda) calculations and 33-point desorption. Wall-flow filters can have high porosity, allowing high loadings of catalyst compositions without excessive backpressure during operation. Coatings and Coating Compositions

[0118] To produce catalyst articles, a substrate as disclosed in this document is coated with a catalyst composition (e.g., LNT and / or LT-NA as disclosed in this document). Coatings are “coating compositions of Petition 870240108964, dated 12 / 20 / 2024, p. 52 / 87 42 / 66 catalyst” or “catalyst coatings”. The terms “catalyst composition” and “catalyst coating composition” are synonymous. An LNT catalyst coating comprises LNT as described herein in the form of a composition, which may include additional components. An LT-NA catalyst coating comprises LT-NA as described herein in the form of a composition, which may include additional components. LNT and LT-NA catalyst compositions may be prepared using a binder, for example, a ZrO2 binder derived from a suitable precursor such as zirconyl acetate or any other suitable zirconium precursor such as zirconyl nitrate.Zirconyl acetate binder provides a coating that remains homogeneous and intact after thermal aging, for example, when the catalyst is exposed to high temperatures of at least about 600 °C, for example, to about 800 °C and above, with water vapor environments of about 5% or more. Other potentially suitable binders include, but are not limited to, alumina and silica. Alumina binders include aluminum oxides, aluminum hydroxides, and / or aluminum oxyhydroxides. Aluminum salts and colloidal forms of alumina can also be used. Silica binders include various forms of SiO2, which include silicates and / or colloidal silica. Binder compositions may include any combination of zirconia, alumina, and / or silica. Other example binders include boehmite, gamma-alumina, and / or delta / theta alumina, as well as silica sol.When present, the binder is typically used in an amount of about 1% by weight to about 5.0% by weight of the total washcoat load. Alternatively, the binder may be zirconia-based or silica-based, for example, zirconium acetate, zirconia sol, or silica sol. When present, the alumina binder is typically used in an amount of about 0.305 g / cm3 (0.05 g / in3) to about 0.061 g / cm3 (ig / in3). In some embodiments, the binder includes... Petition 870240108964, dated 12 / 20 / 2024, p. 53 / 87 43 / 66 alumina.

[0119] As disclosed in the present document above, a substrate is coated with a catalytic composition (e.g., LNT or LT-NA) to form a catalytic article. The catalytic coating may comprise one or more thin adherent coating layers disposed on and adhering to at least a portion of a substrate. In some embodiments, the present catalytic articles may include the use of one or more catalyst layers and combinations of one or more catalyst layers. Catalytic materials may be present on the inlet side of the substrate wall only, on the outlet side only, on both inlet and outlet sides, or the wall itself, in whole or in part, may consist of the catalytic material. The catalytic coating may be on the substrate wall surfaces and / or in the pores of the substrate walls, i.e., “inside” and / or “on” the substrate walls.Thus, the phrase “a catalytic coating disposed on the substrate” means on any surface, for example, on a wall surface and / or on a pore surface. The catalytic coating layer (or layers) may comprise the individual functional components, i.e., the LNT and LT-NA compositions as described in this document.

[0120] A catalyst composition can typically be applied in the form of a washcoat. A washcoat is formed by preparing a fluid paste containing a specified solids content (e.g., about 10% to about 60% by weight) in a liquid vehicle, which is then applied to a substrate and dried and calcined to provide a coating layer. If multiple coating layers are applied, the substrate is dried and calcined after each layer is applied and / or after a desired number of multiple layers are applied. In one or more embodiments, the catalytic material (or materials) is applied to the substrate as a washcoat. Binders Petition 870240108964, dated 12 / 20 / 2024, page 54 / 87 44 / 66 can also be used as described above.

[0121] The catalyst composition(s) observed above (e.g., LNT and LT-NA) can be independently mixed with water to form a flowable paste for the purpose of coating a catalyst substrate, such as a honeycomb-type substrate. In addition to catalyst particles, the flowable paste may optionally contain a binder (e.g., alumina, silica), water-soluble or water-dispersible stabilizers, promoters, associative thickeners, and / or surfactants (including anionic, cationic, nonionic, or amphoteric surfactants). In some embodiments, a typical pH range for the flowable paste is from about 3 to about 6. The addition of acidic or basic species to the flowable paste can be performed to adjust the pH accordingly. For example, in some embodiments, the pH of the flowable paste is adjusted by the addition of ammonium hydroxide or aqueous nitric acid.

[0122] The fluid paste can be ground to intensify the mixing of the particles and the formation of a homogeneous material. Grinding can be carried out in a ball mill, continuous mill or other similar equipment, and the solids content of the fluid paste can be, for example, from about 20% by weight to about 60% by weight, such as from about 20% by weight to about 40% by weight. In one embodiment, the post-grinding fluid paste is characterized by a D90 particle size of about 10 microns to about 40 microns. For example, the D90 particle size can be from about 10 microns to about 30 microns, or from about 10 microns to about 15 microns.

[0123] The fluid paste is then coated onto the catalyst substrate using any suitable washcoat technique. In one embodiment, the catalyst substrate is dipped one or more times into the fluid paste or otherwise coated with the fluid paste. Subsequently, the coated substrate is dried at an elevated temperature (e.g., about 100 °C to about 150 °C) for a period of time (e.g., 10 min. to about 3 hours) and, Petition 870240108964, dated 12 / 20 / 2024, p. 55 / 87 45 / 66 is then calcined by heating, for example, to about 400°C to about 600°C, typically for about 10 minutes to about 3 hours. Following drying and calcination, the final washcoat coating layer can be seen as substantially solvent-free.

[0124] After calcination, the catalyst load obtained by the washcoat technique described above can be determined by calculating the difference between the coated and uncoated weights of the substrate. As will be evident to those skilled in the art, the catalyst load can be modified by altering the rheology of the flow paste. Furthermore, the coating / drying / calcination process to generate a washcoat can be repeated as needed to build up the coating to the desired loading level or thickness. For example, more than one washcoat can be applied. Coating Settings

[0125] The washcoat (or washcoats) comprising the LNT and LT-NA compositions disclosed herein may be applied such that different coating layers may be in direct contact with the substrate. Alternatively, one or more “sub-coatings” may be present such that at least a portion of a catalytic coating layer or coating layers is not in direct contact with the substrate (but is instead in contact with the sub-coating). One or more “overcoatings” may also be present such that at least a portion of the coating layer or layers is not directly exposed to a gas stream or the atmosphere (but is instead in contact with the overcoating).

[0126] Different coating layers may be in direct contact with each other without an “intermediate” overlap zone. Alternatively, different coating layers may Petition 870240108964, dated 12 / 20 / 2024, pp. 56 / 87 46 / 66 not being in direct contact, with a “gap” between the two zones. In the case of a “sub-coating” or “overcoating,” the gap between the different layers is called an “interlayer.” A sub-coating is a layer “below” a coating layer, an overcoating is a layer “over” a coating layer, and an interlayer is a layer “between” two coating layers. The layer(s), sub-coating(s), and overcoating(s) may contain one or more functional compositions or may be free of functional compositions.

[0127] The catalytic coating may comprise more than one thin adherent layer, the layers adhering to each other and the coating adhering to the substrate. The entire coating comprises the individual “coating layers”. The catalytic coating may be “zoned”, comprising catalytic layers in zones. This may also be described as “laterally zoned”. For example, one layer may extend from the inlet end to the outlet end extending about 20%, about 30%, about 40%, about 50%, about 60%, about 70% or about 80% of the substrate length. Another layer may extend from the outlet end towards the inlet end extending about 20%, about 30%, about 40%, about 50%, about 60%, about 70% or about 80% of the substrate length. Different coating layers can be adjacent to each other and do not overlap.Alternatively, different layers may overlap a portion of each other, providing a third “intermediate” zone. The intermediate zone may, for example, extend from about 5% to about 80% of the substrate length, for example, about 5%, about 10%, about 20%, about 30%, about 40%, about 50%, about 60% or about 70% of the substrate length.

[0128] Different layers can extend throughout the Petition 870240108964, dated 12 / 20 / 2024, p. 57 / 87 47 / 66 length of the substrate or they may each extend for a portion of the length of the substrate and may overlap or underlie each other, partially or completely. Each of the different layers may extend from either the inlet or outlet end.

[0129] The zones of the present disclosure are defined by the relationship of the coating layers. With respect to the different coating layers, there are numerous possible zoning configurations. For example, there may be an upstream zone and a downstream zone, there may be an upstream zone, an intermediate zone and a downstream zone, or there may be four different zones, etc. Where two layers are adjacent and do not overlap, there are upstream and downstream zones. Where two layers overlap to some degree, there are upstream, downstream and intermediate zones. Where, for example, one coating layer extends the entire length of the substrate and a different coating layer extends from the outlet end for a certain length and overlaps a portion of the first coating layer, there are upstream and downstream zones. The present catalytic coatings may comprise more than one identical layer.

[0130] In some embodiments, the LNT is placed on a first substrate and the LT-NA is placed on a second substrate. In some embodiments, the first substrate is a honeycomb substrate in the form of a continuous flow filter and the second substrate is a honeycomb substrate in the form of a continuous flow filter or a wall flow filter.

[0131] In some embodiments, the LNT and the LT-NA are arranged on a substrate (e.g., on the same substrate) in a zonal configuration, the substrate having an input end and an output end defining a total length, wherein the LNT is arranged on the substrate extending from the input end to a length of approximately Petition 870240108964, dated 12 / 20 / 2024, pp. 58 / 87 48 / 66 from 20% to about 100% of the total length; and wherein the LT-NA is disposed on the substrate extending from the outlet end to a length of about 20% to about 100% of the total length. In some embodiments, “total length” refers to the entire length of the substrate, in which case it is also referred to as and interchangeable with “substrate length”. In some embodiments, the “total length” may also refer to a certain portion of the entire length of the substrate that is coated with one or more layers of coating as discussed herein. In some embodiments, the substrate is a honeycomb substrate in the form of a continuous flow filter.Figures 3A, 3B, 3C and 3D illustrate some embodiments of various zoned coating layer configurations with two coating layers (e.g., LNT and LT-NA coating layers) on a substrate (e.g., a continuous flow filter substrate) as described in this document according to this embodiment. The configurations of such coating layers are not limited. Figures 3A, 3B, 3C and 3D illustrate wall-mounted or continuous flow filter substrate walls through monolithic walls (200) in which coating layers (201) (e.g., LNT, also referred to as LNT coating layer (201)) and (202) (e.g., LT-NA, also referred to as LT-NA coating layer (202)) are arranged. Monolithic wall flow or continuous flow filter substrates have an “upstream” inlet end (102) and a “downstream” outlet end (103).It should be understood that the various zoned coating layer configurations, as illustrated in Figures 3A, 3B, 3C, and 3D, can also be applied to porous wall-flow substrates, even though the pores, coatings adhering to the pore walls, and obstructed ends are not directly shown in these figures.

[0132] In some embodiments, the LNT coating layer is Petition 870240108964, dated 12 / 20 / 2024, p. 59 / 87 49 / 66 is disposed directly on the substrate and the LT-NA coating layer is disposed directly on the substrate (i.e., there is no overlap between the LNT and LT-NA coating layers). Figure 3A illustrates such an embodiment. Referring to Figure 3A, the coating layer (201) (e.g., the LNT) extends from the inlet end (102) to the outlet for a length of about 50% of the substrate length and the coating layer (202) (e.g., the LT-NA) extends from the outlet end (103) to the inlet for a length of about 50% of the substrate length. As shown in Figure 3A, the coating layers are adjacent to each other, providing an inlet LNT zone (203) (upstream) and an outlet LT-NA zone (204) (downstream).In some embodiments, the LNT coating layer is disposed on the substrate extending from the inlet end (102) to a length of about 20% of the total length, and the LT-NA coating layer is disposed on the substrate extending from the outlet end (103) to a length of about 80% of the total length. In some embodiments, the LNT coating layer is disposed on the substrate extending from the inlet end (102) to a length of about 30% of the total length, and the LT-NA coating layer is disposed on the substrate extending from the outlet end (103) to a length of about 70% of the total length.In some embodiments, the LNT coating layer is disposed on the substrate extending from the inlet end (102) to a length of about 40% of the total length, and the LT-NA coating layer is disposed on the substrate extending from the outlet end (103) to a length of about 60% of the total length. In some embodiments, the LNT coating layer is disposed on the substrate extending from the inlet end (102) to a length of about 50% of the total length, and the LT-NA coating layer is disposed on the substrate extending from. Petition 870240108964, dated 12 / 20 / 2024, pp. 60 / 87 50 / 66 exit end (103) to a length approximately 50% of the total length. In some embodiments, the LNT coating layer is disposed on the substrate extending from the entry end (102) to a length approximately 60% of the total length and the LT-NA coating layer is disposed on the substrate extending from the exit end (103) to a length approximately 40% of the total length. In some embodiments, the LNT coating layer is disposed on the substrate extending from the entry end (102) to a length approximately 70% of the total length and the LT-NA coating layer is disposed on the substrate extending from the exit end (103) to a length approximately 30% of the total length.In some embodiments, the LNT coating layer is disposed on the substrate extending from the inlet end (102) to a length of about 80% of the total length and the LT-NA coating layer is disposed on the substrate extending from the outlet end (103) to a length of about 20% of the total length.

[0133] In some embodiments, the LNT coating layer partially overlaps the LT-NA coating layer (e.g., the LNT is laid on at least a portion of the LT-NA). Such a configuration is represented in Figure 3B. With reference to Figure 3B, the coating layer (202) (e.g., the LT-NA) extends from the exit end (103) to about 50% of the substrate length and the layer (201) (e.g., the LNT) extends from the entry end (102) to more than about 50% of the total length and overlaps a portion of the layer (202), providing an upstream LNT zone (203), a mid-LNT zone (205), and a downstream LT-NA zone (204). In some embodiments, the LNT coating layer is disposed on the substrate extending from the entry end (102) to a length of about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, Petition 870240108964, dated 12 / 20 / 2024, p. 61 / 87 51 / 66 about 50%, about 55%, about 60%, about 65%, about 70%, about 75% or about 80% of the total length, and the LT-NA coating layer is disposed on the substrate extending from the exit end (103) to a length of about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, or about 80% of the total length. For example, in a non-limiting embodiment, the LNT coating layer (201) is disposed on the substrate extending from the inlet end (102) to a length of about 80% of the substrate length and the LT-NA coating layer (202) is disposed on the substrate extending from the outlet end (103) to a length of about 50% of the total length. As such, the LNT coating layer overlaps about 30% of the LT-NA coating layer.One skilled in the art will recognize that many configurations involving overlap are encompassed in this disclosure; consequently, all reasonable and functional percentages of overlap are covered within the scope of this disclosure.

[0134] In some embodiments, the LT-NA (202) coating layer is laid directly on the substrate covering 100% of the total length; and the LNT (201) coating layer is laid on top of the LT-NA (202) coating layer, covering from about 20% to about 80% of the total length. This layered configuration also provides upstream and downstream zones, as shown in a non-limiting embodiment in Figure 3C. With reference to Figure 3C, the LT-NA (202) coating layer extends the entire length of the substrate, with the LNT (201) coating layer partially overlapping the LT-NA (202) coating layer, forming an upstream LNT (203) zone and a downstream LT-NA (204) zone. In some embodiments, the coating layer of Petition 870240108964, dated 12 / 20 / 2024, p. 62 / 87 52 / 66 LNT is disposed in the substrate extending from the entry end (102) to a length of about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75% or about 80% of the total length.

[0135] In some embodiments, the LNT coating layer (201) is laid directly on the substrate covering 100% of the total length; and the LT-NA coating layer (202) is laid on the LNT coating layer (201), covering from about 20% to about 80% of the total length. This alternative layering configuration also provides upstream and downstream zones, as shown in a non-limiting embodiment in Figure 3D. With reference to Figure 3D, the LNT coating layer (201) extends the entire length of the substrate, with the LT-NA coating layer (202) partially overlapping the LNT coating layer (201), forming an upstream LNT zone (203) and a downstream LT-NA zone (204).In some embodiments, the LT-NA coating layer is disposed on the substrate extending from the exit end (103) to a length of about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75% or about 80% of the total length.

[0136] The loading of catalytic coatings on a substrate will depend on the substrate properties, such as porosity and wall thickness. In some embodiments, the catalyst loading of a wall-flow filter is less than the catalyst loadings on a continuous-flow substrate. Catalyzed wall-flow filters are disclosed, for example, in U.S. Patent No. 7,229,597, which is incorporated herein by reference in its entirety. The present Petition 870240108964, dated 12 / 20 / 2024, pp. 63 / 87 53 / 66 LT-NA and LNT catalyst compositions are generally present in the substrate at a concentration of, for example, about 18.30 g / l, about 335.63 g / l, or about 24.40 g / l, about 30.51 g / l, about 36.61 g / l, about 42.71 g / l, about 48.81 g / l, about 54.92 g / l, about 61.02 g / l, about 91.53 g / l, about 122.04 g / l, about 152.55 g / l, about 183.07 g / l, about 213.58 g / l, about 244.09 g / l, about 274.60 g / l, about 305.11 g / l, or about 335.63 g / l (about 0.3 g / in3 to about 5.5 g / in3, or about 0.4 g / in3, about 0.5 g / in3, about 0.6 g / in3, about 0.7 g / in3, about 0.8 g / in3, about 0.9 g / in3, or about 1.0 g / in3 to about 1.5 g / in3, about 2.0 g / in3, about 2.5 g / in3, about 3.0 g / in3, about 3.5 g / in3, about 4.0 g / in3, about 4.5 g / in3, about 5.0 g / in3, or about 5.5 g / in3), based on the substrate.The concentration of a catalyst composition (e.g., LNT and / or LT-NA compositions), or any other component, in a substrate refers to the concentration per any three-dimensional section or zone, for example, any cross-section of a substrate or of the entire substrate.

[0137] In some embodiments, the LNT is effective in removing reducing gases present during a rich condition and is effective in preventing reducing gases from entering the downstream LT-NA. As used in this document, reducing gases refer to components present in the exhaust gas stream during a rich condition and may include, for example, carbon monoxide (CO) and / or hydrocarbons (HC). By rich condition we mean that the air / fuel ratio (lambda; λ) is below 1. In some embodiments, λ is from about 0.80 to about 0.995. In some embodiments, λ is from about 0.90 to 0.95. The air / fuel ratio of the exhaust gas composition can be altered to provide a rich gas stream (rich condition) by a number of methods known to those skilled in the art. Controllers that periodically operate the combustion engine may be used. Petition 870240108964, dated 12 / 20 / 2024, pp. 64 / 87 54 / 66 lean in a rich mode, or more directly alter the air / fuel ratio of the exhaust stream. For example, the air / fuel ratio can be enriched by periodically operating the engine in a rich mode using well-known engine management controls. Alternatively, the exhaust gas stream can be enriched by periodically metering a hydrocarbon (e.g., diesel fuel) into the exhaust gas stream upstream of the LNT. A rich exhaust gas stream can also be formed by adding CO and / or hydrogen (H2) to the exhaust upstream of the LNT, which can be generated, for example, by treating a small amount of hydrocarbon fuel in a partial oxidation reaction. Emission Treatment System

[0138] Another embodiment is provided an emission treatment system for reducing NOx in an exhaust stream from a lean-burning engine, wherein the emission treatment system comprises a lean NOx scavenger (LNT) as disclosed herein, the LNT in fluid communication with and downstream of the lean-burning engine; and a low-temperature NOx adsorber (LT-NA) as disclosed herein, the LT-NA in fluid communication with and downstream of the LNT.

[0139] The engine may be, for example, a diesel engine operating under combustion conditions with excess air than is required for stoichiometric combustion, i.e., lean conditions. In some embodiments, the lean-burn engine is a diesel engine. In other embodiments, the engine may be an engine associated with a stationary source (e.g., electricity generators or pumping stations).

[0140] In the present emission treatment systems and methods, the exhaust gas stream is received at the article (or articles) or treatment system by entering at the upstream end and exiting at the downstream end. The inlet end of a substrate or article is Petition 870240108964, dated 12 / 20 / 2024, pp. 65 / 87 55 / 66 is synonymous with the "upstream" or "front" end. The outlet end is synonymous with the "downstream" or "rear" end. The treatment system is generally downstream of and in fluid communication with an internal combustion engine.

[0141] Emission treatment systems may contain more than one catalytic article positioned downstream of the engine in fluid communication with the exhaust gas stream. Emission treatment systems, as disclosed in this document, may further comprise one or more additional components for treating exhaust gas emissions from a diesel engine or a lean-burning gasoline engine, such as a diesel oxidation catalyst (DOC) and / or a selective catalytic reduction (SCR) catalyst. The emission treatment system may also further comprise a soot filter component and / or additional catalytic components, although the relative placement of the various components of the emission treatment system may vary.In some embodiments, one or more additional components are chosen from a diesel oxidation catalyst (DOC), a soot filter (which may be catalyzed or uncatalyzed), a selective catalytic reduction (SCR) catalyst, an ammonia injection component or ammonia precursor, an ammonia oxidation catalyst (AMOX), and combinations thereof.

[0142] The diesel oxidation catalyst (DOC) component of the exhaust gas treatment system may be located, for example, upstream of the SCR component and / or soot filter. A DOC catalyst component suitable for use in the emission treatment system is capable of effectively catalyzing the oxidation of CO and HC into carbon dioxide (CO2). In some embodiments, the oxidation catalyst is capable of converting at least 50% of the CO or HC component present in the exhaust gas.

[0143] In addition to treating exhaust gas emissions through Petition 870240108964, dated 12 / 20 / 2024, pp. 66 / 87 56 / 66 Using a DOC component, emission treatment systems may employ a soot filter for particulate matter removal. The soot filter may be located upstream or downstream of the DOC. For example, the soot filter will be located downstream of the DOC. In some embodiments, the soot filter is a catalyzed soot filter (CSF). The CSF may comprise a substrate coated with washcoat particles containing one or more catalysts to burn trapped soot and / or oxidize emissions from the exhaust gas stream. In general, the soot-burning catalyst may be any known catalyst for soot combustion. For example, the CSF may be coated with one or more high surface area refractory oxides (e.g., an aluminum oxide or ceria-zirconia) for combustion of CO and unburned hydrocarbons and, to some extent, particulate matter.The soot-burning catalyst may be an oxidation catalyst comprising one or more precious metal catalysts (e.g., platinum and / or palladium).

[0144] The emission treatment systems as disclosed in this document may further comprise a selective catalytic reduction (SCR) component. The SCR component may be located upstream or downstream of the DOC and / or soot filter. A suitable SCR catalyst component for use in the emission treatment system is capable of effectively catalyzing the reduction of the NOx exhaust component at temperatures as high as approximately 650 °C. Furthermore, the SCR must be active for NOx reduction even under low load conditions, which are typically associated with lower exhaust temperatures. In some embodiments, the catalyst article is capable of converting at least approximately 50% of the NOx component (e.g., NO) to N2, depending on the amount of reductant added to the system. Another attribute for the SCR composition is that it possesses the ability to catalyze the reaction of O2 with any Petition 870240108964, dated 12 / 20 / 2024, pp. 67 / 87 57 / 66 excess NH3 to form N2, so that NH3 is not emitted into the atmosphere. The SCR catalyst compositions used in the emission treatment system must also have thermal resistance to temperatures exceeding 650 °C. These high temperatures may be encountered during the regeneration of the catalyzed soot filter. Suitable SCR catalyst compositions are described, for example, in US Patents 4,961,917 and 5,516,497, each of which is incorporated herein by reference in its entirety. In some embodiments, the emission treatment system further comprises a downstream SCR catalyst article in fluid communication with the LNT and LT-NA.

[0145] An example of an emission treatment system is illustrated in Figure 4, which represents a schematic representation of a non-limiting exhaust gas treatment system (20), according to embodiments of the present disclosure. As shown, the emission treatment system (20) may include a plurality of catalyst components in series downstream of an engine (22), such as a lean-burn gasoline engine. At least one of the catalyst components may be the LNT - LT-NA as set forth in this document. Figure 4 illustrates five catalyst components (24, 26, 28, 30, 32) in series; however, the total number of catalyst components may vary and five components are only a non-limiting example.

[0146] Without limitation, Table 1 presents various exhaust gas treatment system configurations of one or more embodiments. Note that each catalyst is connected to the next catalyst via exhaust ducts so that the engine is upstream of catalyst A, which is upstream of catalyst B, which is upstream of catalyst C, which is upstream of catalyst D, which is upstream of catalyst E (when present). The reference to Components A to E in the table can be cross-referenced with Petition 870240108964, dated 12 / 20 / 2024, pp. 68 / 87 58 / 66 the same designations as in Figure 4.

[0147] The reference to SCR in the table refers to an SCR catalyst. The reference to SCRoF (or SCR in filter) refers to a particulate or soot filter (e.g., a wall-flow filter). The reference to AMOx in the table refers to an ammonia oxidation catalyst, which may be supplied downstream of an SCR to remove any ammonia that runs off from the exhaust gas treatment system. As recognized by one skilled in the art, in the configurations listed in Table 1, any one or more of components A, B, C, D, or E may be arranged in a particulate filter, such as a wall-flow filter, or a continuous-flow honeycomb substrate. In one or more embodiments, an engine exhaust system comprises one or more catalyst compositions mounted in a position near the engine (in a coupled position, CC), with additional catalyst compositions in a position under the vehicle body (in an under-floor position, UF).In one or more embodiments, the exhaust gas treatment system may also include an ammonia or a precursor ammonia injection component. In some embodiments, the emission treatment system also includes a lambda sensor located downstream of the LNT. In one or more embodiments, the lambda sensor is in communication with an on-board diagnostic and / or engine control system. The lambda sensor used may be any suitable lambda sensor, for example, a heated exhaust gas oxygen sensor (HEGO) or a universal exhaust gas oxygen sensor (UEGO). Table 1. Possible Gas Treatment System Configurations Exhaustion Component A Component B Component C Component D Component E DOC LNT - LT-NA SCR AMOx optional - DOC LNT - LT-NA SCRoF AMOx optional - DOC LNT - LT-NA SCRoF SCR AMOx optional Petition 870240108964, dated 12 / 20 / 2024, pp. 69 / 87 59 / 66 Component A Component B Component C Component D Component E DOC LNT - LT-NA SCR SCRoF AMOx optional DOC LNT - LT-NA CSF SCR AMOx optional LNT - LT-NA - SCR AMOx optional - LNT - LT-NA - SCR SCRoF AMOx optional LNT - LT-NA - SCRoF SCR AMOx optional LNT - LT-NA - CSF SCR AMOx optional

[0148] To simplify the representation of the exhaust gas treatment system as disclosed in this document, the LNT and LT-NA are illustrated as a single component A or B; however, this is a non-limiting embodiment. As described above, the LNT and LT-NA may each comprise a separate component (e.g., each may be arranged on a separate substrate), or they may be combined on a single substrate, for example, in a zoned or layered configuration, as a single component. Two exemplary configurations of the LNT and LT-NA are illustrated in Figure 5A and Figure 5B, which depict schematic representations of non-limiting configurations according to embodiments of this disclosure. With reference to Figure 5A, the LNT and LT-NA are arranged on separate substrates and are present in the emission treatment system as two separate components.With reference to Figure 5B, the LNT and LT-NA are arranged on the same substrate and / or are present in the emission treatment system as a single component. Methods for Treating a Gas Exhaust Stream

[0149] Aspects of the present disclosure are directed to a method for reducing NOx in an exhaust stream from a lean-burning engine, wherein the method comprises bringing the exhaust gas stream into contact with the emission treatment system of the present disclosure. In some embodiments, the method further comprises operating the lean-burning engine in a rich mode for a period of time, producing a rich exhaust stream containing reducing gases comprising hydrocarbons. Petition 870240108964, dated 12 / 20 / 2024, pp. 70 / 87 60 / 66 (HC) and carbon monoxide (CO); passing the rich exhaust gas stream through the LNT, thus creating a reducing atmosphere therein; and regeneration of the LNT in the reducing atmosphere; wherein the time period during which the lean-burn engine is operated in rich mode is sufficient to regenerate the LNT without exceeding the adsorption capacity of the LNT for the reducing gases. As used in this document, “rich mode” refers to the operation of the lean-burn engine under a less than stoichiometric air / fuel ratio (e.g., λ < 1) such that the hydrocarbon fuel consumed by the engine is not fully burned. This results in an exhaust stream containing unburned or partially burned hydrocarbons, herein referred to as a “rich condition” or “reducing condition”. In contrast, “lean mode” refers to the normal, lean operation of the lean-burn mechanism (e.g., λ > 1).Rich mode operation is a method of producing a rich condition used to regenerate an LNT (e.g., a “NOx pulse”). Alternatively, a NOx pulse can be created by introducing hydrocarbons or other reducing gases (e.g., CO or H2) into the exhaust stream via an injector downstream of the engine and upstream of one or more catalytic converters.

[0150] As disclosed above, the use of an LT-NA downstream of an LNT would normally be affected by the fact that the NOx adsorption capacity of the LT-NA would be deactivated by the rich-condition NOx pulse used to regenerate the LNT. However, by placing the LT-NA downstream of the LNT and controlling the rich-condition time period, the total amount of reducing gases in contact with the LNT can be controlled. As such, the LT-NA can be protected from exposure to reducing gases by the oxygen storage function of the LNT. In some embodiments, when the exhaust gas stream is switched from the normal lean (oxidizing) condition to the rich (reducing) condition, there is a period of several seconds during which all the reducing agent is Petition 870240108964, dated 12 / 20 / 2024, pp. 71 / 87 61 / 66 consumed on the LNT by the oxygen storage component (OSC). During this time, the LNT effluent entering the LT-NA is stoichiometric (i.e., contains no O2 or reducing agent). If the composition and timing of this reducing pulse are controlled such that there is no breakdown of the LNT reducing agent, then the downstream LT-NA will be protected from the negative effect of the rich deNOx pulse (i.e., reducing agent). In some embodiments, the timing of the deNOx pulse is controlled by monitoring the LNT exhaust stream effluent and responsively adjusting the air / fuel ratio. Consequently, in some embodiments, the method for reducing NOx in an exhaust stream of a lean-burning engine further comprises monitoring the exhaust stream exiting the LNT with a lambda sensor; and returning the lean-burning engine to a lean mode, ending the lean-burning engine's operating time in rich mode; thus avoiding exposure of the LNT to the reducing atmosphere.Someone skilled in the art will recognize the standard components and their integration into the engine management system to provide such control over the deNOx pulse.

[0151] The present systems and methods are suitable for treating exhaust gas streams from mobile emission sources, such as trucks and automobiles. The present systems and methods are also suitable for treating exhaust streams from stationary sources, such as power plants. Examples of Modalities:

[0152] Without limitation, some forms of this disclosure include: 1. An emission treatment system for reducing NOx in the exhaust stream of a lean-burning engine, wherein the emission treatment system comprises: a lean NOx pickup (LNT) comprising a component Petition 870240108964, dated 12 / 20 / 2024, pp. 72 / 87 62 / 66 oxygen storage (OSC) and a first platinum group metal (PGM) component, wherein the LNT is in fluid communication with and downstream of the lean-burn engine; and a low-temperature NOx adsorber (LT-NA) comprising a molecular sieve comprising a second PGM component, wherein the LT-NA is in fluid communication with and downstream of the LNT. 2. The emission treatment system of Mode 1, in which LNT is placed on a first substrate and LT-NA is placed on a second substrate. 3. The emission treatment system of Mode 1 or 2, wherein the first substrate is a honeycomb substrate in the form of a continuous flow filter and the second substrate is a honeycomb substrate in the form of a continuous flow filter or a wall flow filter. 4. The emission treatment system of Mode 1, in which the LNT and LT-NA are arranged on a substrate in a zoned configuration, and the substrate having an inlet end and an outlet end defining a total length; wherein the LNT is disposed on the substrate extending from the inlet end to a length of about 20% to about 100% of the total length; and wherein the LT-NA is disposed on the substrate extending from the outlet end to a length of about 20% to about 100% of the total length. 5. The emission treatment system of Mode 4, in which the LNT is placed directly on the substrate covering 100% of the total length; and the LT-NA is placed on the LNT, covering from about 20% to about 80% of the total length. 6. The Mode 4 emission processing system, in which Petition 870240108964, dated 12 / 20 / 2024, pp. 73 / 87 63 / 66 The LT-NA is placed directly on the substrate, covering 100% of the total length; and the LNT is placed on the LT-NA, covering from about 20% to about 80% of the total length. 7. The emission treatment system of Mode 4, in which LNT is placed directly on the substrate and LT-NA is placed directly on the substrate. 8. The emission treatment system of any of the Modalities 4 to 7, in which the substrate is an alveolar substrate in the form of a continuous flow filter. 9. The emission treatment system for any of the Modalities 1 to 8, in which the OSC includes ceria. 10. The emission treatment system of Modality 9, in which the OSC further comprises one or more selected from zirconia, alumina, silica, titania, lantana, barium, praseodymia, yttria, samaria, gadolinium and combinations thereof. 11. The emission treatment system of any of the Modalities 1-10, in which the first PGM component is chosen from platinum, palladium, rhodium, and combinations thereof. 12. The emission treatment system of any of the Modalities 1-11, in which the first PGM component is palladium. 13. The emission treatment system of any of the Modalities 1 to 12, in which the second PGM component resides in ion exchange sites in the molecular sieve. 14. The emission treatment system of any of the Modalities 1 to 13, in which the second PGM component is chosen from platinum, palladium, rhodium, and combinations thereof. 15. The emission treatment system of any of the Modalities 1 to 14, in which the second component of PGM comprises a Petition 870240108964, dated 12 / 20 / 2024, pp. 74 / 87 64 / 66 is a mixture of platinum and palladium. 16. The emission treatment system of any one of Embodiments 1 to 15, wherein the molecular sieve has a framing type selected from ABW, ACO, AEI, AEL, AEN, AET, AFG, AFI, AFN, AFO, AFR, AFS, AFT, AFT, AYPC, AFX, AYPC, AYPC APD, AST, ASV, ATN, ATO, ATS, ATT, ATV, AVL, AWO, AWW, BCT, BEA, BEC, BIK, BOF, PÂNTANO, BOZ, BPH, BRE, BSV, CAN, CAS, CDO, CFI, CGF, CGS, CHA, CHI, CHI, CON, CON, DFO, DFO, DFT, DFT DOH, DON, EAB, EDI, EEI, EMT, EON, EPI, ERI, ESV, ETR, EUO, EZT, FAU, FER, FRA, GIS, GIU, GME, GON, GOO, HEU, IFR, IFY, IHW, FMI, IRN, ISV, ITE, ITG, ITHR, IWW, IWW, IWW, IWV JBW, JRY, JSR, JST, KFI, LAU, LEV, LIO, LIT, LOS, LOS, LTA, LTF, LTL, LTN, MAR, MAZ, MAY, MEL, MEP, MER, MFI, MFS, SEG, MOR, MOZ, MRE, MSE, MSO, MTF, MTF, MTF, MMT, MWTT, MW, MW MWW, NAB, NAT, NES, NON, NPO, NPT, NSI, OBW, OFF, OK, OSI, OSO, OWE, PAR, PAU, PCR, PHI, PON, TROCADILHO, RHO, RON, RRO, RSN, RTE, RTH, RUT, RWR, RWY, SAF, SAF, SAS, SAV, SAV, SAV, SBT, SBT, SBT SCO, COSTURAR, SFE, SFF, SFG,SFH, SFN, SFO, SFS, SFW, SGF, SGT, SIV, SOD, SOF, SOS, SSF, SSY, STF, STI, STO, STT, STW, SVR, SZR, TER, THO, TON, TSC, TUN, UEI, UFI, UOS, UOZ, USI, UTL, UWY, VET, VFI, VNI, VSV, WIE, WEN, YUG, ZON and mixtures or intergrowths thereof., 17. The emission treatment system of any of the Modalities 1 to 16, in which the molecular sieve has a frame type chosen from AFX, CHA and FER. 18. The emission treatment system of any of the Modalities 1 to 17, where the molecular sieve is an aluminosilicate zeolite. 19. The emission treatment system of any of the Modalities 1 to 17, where the molecular sieve is chosen from Type A, Petition 870240108964, dated 12 / 20 / 2024, pp. 75 / 87 65 / 66 beta zeolite, chabazite, erionite, faujasite, ferrierite, Mordenite, silicalite, SSZ-13, stilbite, ZSM-5, ZSM-11, ZSM-23, ZSM-48, zeolite X, and zeolite Y. 20. The emission treatment system of any of the Modalities 1 to 19, in which the molecular sieve is ferrierite. 21. The emission treatment system of any of the Modalities 1 to 20, in which the LNT is configured to remove reducing gases present during a rich condition; and in which the LNT is configured to prevent reducing gases from entering the downstream LT-NA. 22. The emission treatment system of any of the Modalities 1 to 21, also comprising a lambda sensor located downstream of the LNT. 23. The emission treatment system of any of the Modalities 1 to 22, further comprising one or more selected from a selective catalytic reduction (SCR) catalyst, an ammonia injection component or ammonia precursor, a diesel oxidation catalyst (DOC), a catalyzed soot filter (CSF), an ammonia oxidation catalyst (AMOX) and combinations thereof. 24. The emission treatment system of Mode 23, in which the SCR is downstream and in fluid communication with the LT-NA. 25. A method for reducing NOx in an exhaust stream from a lean-combustion engine, the method comprising contacting the exhaust gas stream with the emission treatment system of any of the Embodiments 1 to 24. 26. The method of Modality 25, also comprising: to operate the lean-burn engine in a rich mode that produces a rich exhaust stream containing reducing gases comprising hydrocarbons (HC) and carbon monoxide (CO); passing the rich exhaust gas stream through the LNT, creating Petition 870240108964, dated 12 / 20 / 2024, pp. 76 / 87 66 / 66 thus a reducing atmosphere in the same; and regenerate the LNT in the reducing atmosphere, where the lean-burn engine is operated in rich mode to sufficiently regenerate the LNT without exceeding the adsorption capacity of the LNT for the reducing gases. 27. The method of Modality 26, also comprising: Monitor the exhaust stream exiting the LNT with a lambda sensor; and return the lean-burning engine to a lean mode to finish operating the lean-burning engine in rich mode according to a monitoring result, thus avoiding exposure of the LT-NA to the reducing atmosphere.

[0153] It will be readily apparent to one skilled in the relevant techniques that appropriate modifications and adaptations to the compositions, methods, and applications described herein can be made without departing from the scope of any embodiments or aspects thereof. The compositions and methods provided are examples and are not intended to limit the scope of the embodiments. All the various embodiments, aspects, and options disclosed herein may be combined in all variations. The scope of the compositions, formulations, methods, and processes described herein includes all actual or potential combinations of embodiments, aspects, options, examples, and preferences herein. All patents and publications cited herein are incorporated by reference for the specific teachings thereof, as noted, unless other specific incorporation statements are specifically provided.

Claims

1. EMISSION TREATMENT SYSTEM FOR REDUCING NOx IN AN EXHAUST STREAM FROM A LEAN-BURNING ENGINE, characterized by comprising: a lean NOx collector (LNT) comprising an oxygen storage component (OSC) and a first platinum group metal (PGM) component, wherein the LNT is in fluid communication with and downstream of the lean-burning engine; and a low-temperature NOx adsorber (LT-NA) comprising a molecular sieve comprising a second PGM component, wherein the LT-NA is in fluid communication with and downstream of the LNT, wherein the second PGM component comprises a mixture of platinum and palladium.

2. SYSTEM, according to claim 1, characterized in that the LNT is arranged on a first substrate, and the LT-NA is arranged on a second substrate.

3. SYSTEM, according to claim 2, characterized in that the first substrate is an alveolar substrate in the form of a continuous flow filter, and the second substrate is an alveolar substrate in the form of a continuous flow filter or a wall flow filter.

4. SYSTEM, according to claim 1, characterized in that the LNT and LT-NA are arranged on a substrate in a zoned configuration, and the substrate has an input end and an output end defining a total length; wherein the LNT is arranged on the substrate extending from the input end to a length of about 20% to about 100% of the total length; and wherein the LT-NA is arranged on the substrate extending from the output end to a length of about 20% to about 100% of the total length.

5. SYSTEM, according to claim 4, characterized in that the LNT is disposed directly on the substrate covering 100% of the total length; and the LT-NA is disposed on the LNT, covering from about 20% to about 80% of the total length.

6. SYSTEM, according to claim 4, characterized in that the LT-NA is disposed directly on the substrate covering 100% of the total length; and the LNT is disposed on the LT-NA, covering from about 20% to about 80% of the total length.

7. SYSTEM, according to claim 4, characterized in that the LNT is disposed directly on the substrate, and the LT-NA is disposed directly on the substrate.

8. SYSTEM, according to any one of claims 4 to 7, characterized in that the substrate is an alveolar substrate in the form of a continuous flow filter.

9. SYSTEM, according to any one of claims 1 to 8, characterized in that the OSC comprises ceria.

10. SYSTEM, according to claim 9, characterized in that the OSC further comprises one or more materials selected from zirconia, alumina, silica, titania, lantana, barium, praseodymia, yttria, samaria, gadolinium and combinations thereof.

11. SYSTEM, according to any one of claims 1 to 10, characterized in that the first component of PGM is chosen from platinum, palladium, rhodium and combinations thereof.

12. SYSTEM, according to any one of claims 1 to 11, characterized in that the second PGM component resides in ion-exchange sites in the molecular sieve. Petition 870240108964, dated 12 / 20 / 2024, pp. 79 / 87 3 / 4 13. SYSTEM, according to any one of claims 1 to 12, characterized in that the molecular sieve has a type of structure chosen from AFX, CHA and FER.

14. SYSTEM, according to any one of claims 1 to 13, characterized in that the molecular sieve is an aluminosilicate zeolite.

15. SYSTEM, according to any one of claims 1 to 13, characterized in that the molecular sieve is chosen from Type A, beta zeolite, chabazite, erionite, faujasite, ferrierite, mordenite, silicalite, SSZ-13, stilbite, ZSM-5, ZSM-11, ZSM-23, ZSM-48, zeolite X, and zeolite Y.

16. SYSTEM, according to any one of claims 1 to 15, characterized in that the molecular sieve is ferrierite.

17. SYSTEM, according to any one of claims 1 to 16, characterized by further comprising a lambda sensor disposed downstream of the LNT.

18. SYSTEM, according to any one of claims 1 to 17, characterized by further comprising one or more selected from a selective catalytic reduction (SCR) catalyst, an ammonia injection component or ammonia precursor, a diesel oxidation catalyst (DOC), a catalyzed soot filter (CSF), an ammonia oxidation catalyst (AMOX), and combinations thereof.

19. SYSTEM, according to claim 18, characterized in that the SCR is downstream and in fluid communication with the LT-NA.

20. METHOD FOR REDUCING NOx IN AN EXHAUST STREAM OF A LEAN-BURNING ENGINE, characterized by comprising bringing the exhaust gas stream into contact with the emission treatment system, as defined in any one of claims 1 to 19.

21. METHOD, according to claim 20, characterized in Petition 870240108964, dated 12 / 20 / 2024, page 80 / 87 4 / 4, by further comprising: operating the lean-burn engine in a rich mode that produces a rich exhaust stream containing reducing gases comprising hydrocarbons (HC) and carbon monoxide (CO); passing the rich exhaust gas stream through the LNT, thereby creating a reducing atmosphere therein; and regenerating the LNT in the reducing atmosphere, wherein the lean-burn engine is operated in rich mode to sufficiently regenerate the LNT without exceeding the adsorption capacity of the LNT for the reducing gases.

22. METHOD, according to claim 21, further characterized by comprising: monitoring the exhaust stream exiting the LNT with a lambda sensor; and returning the lean-burning motor to a lean mode to finish operating the lean-burning motor in rich mode according to a monitoring result, thus avoiding exposure of the LT-NA to the reducing atmosphere.

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