Zeolite catalysts having paired heteroatoms and methods thereof

Abstract

The present disclosure relates to zeolite catalysts having aging durability and improved catalytic activity. For example, the zeolite catalyst includes a specific aluminum distribution, such as the positioning of two framework aluminum atoms in the zeolite structure at the third nearest neighbor (3NN) relative positions in the framework. The zeolite catalyst has two tetrahedrally coordinated Al sites separated by two tetrahedrally coordinated Si sites. The present disclosure also relates to processes and methods for their characterization and use.

Description

[0001] This application claims priority to U.S. Application No. 63 / 263,599, filed November 5, 2021, the disclosure of which is incorporated herein by reference in its entirety.

[0002] This disclosure relates to zeolite catalysts exhibiting aging durability and improved catalytic activity. For example, the zeolite catalyst includes a specific aluminum distribution, i.e., the positioning of two aluminum atoms at 3NN relative positions in the zeolite structure. The zeolite catalyst has two tetrahedral Al sites separated by two tetrahedral Si sites. This disclosure also relates to processes and methods for their characterization and use.

[0003] Molecular sieves (such as zeolites) have been used for the selective catalytic reduction (SCR) of nitrogen oxides (NOx) with reducing agents (such as ammonia, urea, or hydrocarbons). x Zeolites are crystalline materials with fairly uniform pore sizes, ranging in diameter from about 3 angstroms to about 25 angstroms, depending on the type of zeolite and the type and number of cations included in the zeolite lattice. Zeolites with 8-membered ring pore openings and bi-6-membered ring secondary building units, such as those with cage-like structures, are of interest as SCR catalysts. The number of rings refers to the number of atoms approximately tetrahedral coordinated in the interconnecting rings of the zeolite framework. Included in this category are zeolites with a chalcogenide (CHA) crystal structure, which are microporous zeolites with 8-membered ring pore openings (about 3.8 angstroms) that are accessible through their 3D pores. The cage-like structure is generated by the connection of bi-6-membered ring building units through 4-membered rings.

[0004] Chalcogenide (CHA) zeolite catalysts have caused NO x There is interest in selective catalytic reduction (SCR). The amount of Al may play a role in the reactivity and stability of the zeolite framework, but currently there is no method to provide direct evidence for determining the location of Al within the zeolite framework, and the type and extent of the effect of Al distribution on reactivity is unclear.

[0005] Metal-promoted zeolite catalysts, also frequently referred to as ion-exchange zeolites or copper- and / or iron-supported zeolites, particularly copper-promoted and iron-promoted zeolite catalysts, are known for their use in SCR of nitrogen oxides with ammonia and can typically be prepared via metal ion-exchange processes. However, it has been found that the activity of many metal-promoted zeolites begins to decline under harsh hydrothermal conditions. This decline in activity is thought to be due to zeolite destabilization, such as through dealumination or reduction of the metal-containing catalytic sites within the zeolite.

[0006] Under hydrothermal conditions, catalysts used in SCR processes should ideally retain high catalytic activity over a wide range of operating temperature conditions (e.g., from about 150°C to about 600°C or higher). Hydrothermal conditions are encountered in practice because water is a byproduct of fuel combustion, and high-temperature hydrothermal conditions occur in diesel exhaust applications, such as during the regeneration of fume filters (components in exhaust treatment systems used to remove carbon-containing particles).

[0007] SCR process removes nitrogen oxides (NOx) x NO is converted into nitrogen (N2) and water (H2O). The expected NO... x The process selectively converts NO to N2 within the exhaust gas stream of an internal combustion engine while minimizing the formation of undesirable N2O. Undesirable N2O formation can be observed as the molar percentage of (NO + NO2) converted to N2O. Nitrogen oxides (NO...) x It can include N2O, NO, N2O3, NO2, N2O4, N2O5 or NO3.

[0008] Zeolites (such as aluminosilicate zeolites) offer significant technological advantages due to their high surface area, well-defined subnanopores, and cation exchange sites, enabling catalytic applications in hydrocarbon conversion or pollution reduction. The catalytic properties of zeolites stem from the non-stoichiometric substitution of SiO4 tetrahedra by AlO4 tetrahedra, which introduces a negative framework charge balanced by exchangeable cations. Solid acids (H... + Aluminosilicate zeolites in the form of metal exchange (such as octahedral zeolite (Y zeolite) and chalcogenite (CHA, zeolite SSZ-13)) are highly active heterogeneous catalysts for hydrocarbon rearrangement reactions (including cracking or methanol-to-light olefins). x The compounds are converted into N2 and H2O to reduce NO in automobile exhaust. x The catalysts used for emission are of interest. Examples of metal-exchanged forms used in this application include copper and iron. Different copper-exchanged zeolites exhibit very different reactivity, and little is known about them at the atomic level. This difference is due to the unique local composition and atomic environment of the framework heteroatoms (such as aluminum), which directly influences the distribution of exchangeable cations at catalytically important sites. Measuring and understanding the effects of the framework heteroatom environment on catalytic activity and selectivity has been challenging, partly due to the disordered distribution of heteroatoms within the zeolite framework, which hinders detailed analysis by conventional scattering or spectroscopic techniques. In contrast, solid-state nuclear magnetic resonance (NMR) spectroscopy measurements of NMR active materials (e.g., aluminum silicate zeolites) in zeolites are more suitable for analysis. 1 H, 27 Al and 29 Si is sensitive to local chemical environments. Solid-state NMR spectroscopy can be used to identify different types of...27 Al and 29 Si substances and establish their relative amounts and proximity, including for exchangeable copper cations.

[0009] It is desirable to prepare improved zeolite catalysts with higher hydrothermal stability, for example, for the conversion of methanol or propanol to olefins. Additionally, it is desirable to prepare improved zeolite catalysts with higher catalytic activity and selectivity. This disclosure provides zeolite catalysts with aging durability and improved catalytic activity. For example, the zeolite catalyst includes a specific aluminum distribution, namely the positioning of two tetrahedral coordinated aluminum atoms at sites separated by two Si tetrahedral sites in the zeolite structure and at relative positions in the third nearest neighbor (3NN) configuration. This disclosure also relates to processes and methods for their characterization and use.

[0010] This disclosure generally provides a zeolite catalyst having paired framework aluminum atoms, wherein the paired aluminum atoms are the third nearest neighbors (3NN) in the zeolite structure, and wherein the zeolite catalyst has aging durability, improved catalytic activity, or a combination thereof.

[0011] In some implementations, the zeolite catalyst is a CHA zeolite catalyst.

[0012] In some embodiments, the zeolite catalyst is a CHA zeolite catalyst, wherein the CHA zeolite catalyst is a copper-CHA catalyst.

[0013] In some embodiments, the zeolite in the zeolite catalyst composition is a microporous zeolite.

[0014] In some embodiments, the pore zeolite in the zeolite catalyst composition is of the AEI zeolite framework type.

[0015] In some embodiments, the pore zeolite in the zeolite catalyst composition is of the AFX zeolite framework type.

[0016] In some embodiments, the porous zeolite in the zeolite catalyst composition is of the AFT zeolite framework type.

[0017] In some implementations, when using 2D 29 Si- 29 During SiJ-mediated NMR measurements, the zeolite catalyst exhibited performance at -104 ppm (i.e., Hz / 10) in the single quantum (SQ) dimension. 6 Hz ) In the range of -108 ppm and in the range of -208 ppm to -212 ppm in the dual quantum (DQ) dimension 29 Si signal 29 Si NMR characteristics.

[0018] In some implementations, when using solid-state 2D27 Al{ 29 During Si}J-mediated heteronuclear multiple quantum correlation (HMQC) NMR measurements, zeolite catalysts exhibit [the following characteristics / functions]: 29 Si dimension in the range of -98ppm to -100ppm and in 27 The Al dimension is in the range of 55ppm to 60ppm. 29 Si NMR characteristics.

[0019] In some embodiments, the zeolite catalyst exhibits aging durability after hydrothermal aging at 800°C, and the zeolite catalyst exhibits 10% higher NO content compared to zeolite without 3NN sites. x Conversion rate.

[0020] In some embodiments, the zeolite catalyst exhibits aging durability after hydrothermal aging at 850°C, wherein the zeolite catalyst exhibits at least 50% NO. x Conversion rate.

[0021] In some embodiments, the zeolite catalyst exhibits improved catalytic activity for methanol dimerization, with a conversion rate approximately 10% higher compared to zeolites without 3NN sites.

[0022] In some embodiments, the zeolite catalyst has a SiO2 / Al2O3 ratio (SAR) selected from 8-40, 10-30, or 11-25.

[0023] In some embodiments, the zeolite catalyst also contains copper (Cu), wherein the Cu content corresponds to a Cu / Al ratio selected from 0.2 to 0.5, 0.25 to 0.45, or 0.3 to 0.4.

[0024] In some implementations, the catalyst article effectively reduces nitrogen oxides (NOx) from lean-burn engine exhaust. x Catalyst products include substrate supports having selective catalytic reduction (SCR) catalysts containing zeolite catalysts.

[0025] In some embodiments, the SCR catalyst has a honeycomb substrate as the substrate support and is optionally made of metal or ceramic.

[0026] In some implementations, the SCR catalyst is a flow-through substrate or a wall-flow filter.

[0027] In some implementations, the exhaust gas treatment system includes: a lean-burn engine that generates an exhaust gas flow; and an SCR catalyst located downstream of the lean-burn engine and in fluid communication with the exhaust gas flow.

[0028] In some implementations, the exhaust gas treatment system further includes one or more of the following:

[0029] Diesel engine oxidation catalyst (DOC), which is located upstream of the SCR catalyst product; a smoke filter, which is located upstream of the catalyst product; and an ammonia oxidation catalyst (AMOX), which is located downstream of the catalyst product.

[0030] In some embodiments, a process for preparing a diesel engine oxidation catalyst (DOC) includes:

[0031] Prepare a zeolite catalyst composition; apply the catalyst as a coating onto a ceramic or metal honeycomb substrate; dry the coated substrate; calcine the coated substrate at a temperature in the range of 400°C to 800°C.

[0032] These and other features, aspects, and advantages of this disclosure will become apparent from the following detailed description and the accompanying drawings, which are briefly described below. Other aspects and advantages of the disclosed subject matter will become apparent from the following text. Attached Figure Description

[0033] To provide an understanding of the embodiments of this disclosure, reference is made to the accompanying drawings, wherein reference numerals indicate components of exemplary embodiments of the disclosed subject matter. The drawings are exemplary only and should not be construed as limiting the scope of this disclosure. The disclosure described herein is illustrated in the drawings by way of example, not limitation. For simplicity and clarity, features illustrated in the drawings are not necessarily drawn to scale. For example, the dimensions of some features may be enlarged relative to other features for clarity. Furthermore, reference numerals are repeated in the drawings where deemed appropriate to indicate corresponding or similar elements.

[0034] Figure 1(A) shows the dehydration process in a sealed NMR rotor at 150°C. + - 1D direct excitation in situ of methanol reacting to form dimethyl ether on samples A and B. 13 Representative spectra of ¹H NMR.

[0035] Figure 1(B) shows the direct excitation method as shown in Figure 1(A). 13 The methanol conversion rates of samples A and B over time at 125°C and 150°C were tracked by C NMR.

[0036] Figure 1(C) shows the NO content of samples C, D, and G. x Conversion rate data.

[0037] Figure 1(D) shows the N2O selectivity data for samples C, D, and G.

[0038] Figure 1(E) shows the NO content of samples A and B. x Conversion rate data.

[0039] Figure 2(A) shows 1D direct excitation 29 Si MAS NMR spectrum.

[0040] Figure 2(B) shows the hydrated H + - Direct 1D excitation of samples A and B in form 27 Al MAS NMR spectrum.

[0041] Figure 3(A) shows the hydrated H + 2D of sample A 29 Si{ 29 Si}J-mediated single-quantum-double-quantum (SQ-DQ) NMR spectra.

[0042] Figure 3(B) shows the hydrated H + - 2D of sample B in form 29 Si{ 29 Si}J-mediated SQ-DQ NMR spectra.

[0043] Figure 4(A) shows the hydrated H + 2D of sample A 27 Al{ 29 Si}J-mediated HQMC NMR spectra, and the 1D spectra obtained for sample A under the same conditions are shown along the vertical axis of each 2D spectrum. 29 Si{ 1 H} Cross-polarized magic angle rotation (CP-MAS) spectrum.

[0044] Figure 4(B) shows the hydrated H + - 2D of sample B in form 27 Al{ 29 Si} J The mediated HQMC NMR spectra are shown, and the 1D spectra obtained for sample B under the same conditions are shown along the vertical axis of each 2D spectrum. 29 Si{ 1 H}CP-MAS spectroscopy.

[0045] Figure 5 This is a diagram of the catalytic sites in aluminosilicate zeolite (SSZ-13).

[0046] Figure 6 It shows Cu 2+ The structure of the "paired" Al framework of the catalyst.

[0047] Figure 7(A) illustrates the results revealed by 2D NMR. 29 Si-O- 29Differences in Si connectivity.

[0048] Figure 7(B) illustrates the 2D NMR spectra corresponding to those shown in Figure 7(A). 29 Si-O- 29 A schematic diagram illustrating the differences in Si connectivity.

[0049] Figure 8 It is hydrated H + - 2D of sample C in form 29 Si{ 29 SiJ-mediated solid-state NMR spectra. Spectra were obtained at 9.4 T, 8 kHz MAS, and 100 K.

[0050] Figure 9(A) shows the hydrated H + - 2D of sample C in form 29 Si{ 29 Solid-state NMR spectra mediated by Si} dipole. Spectra were obtained at 9.4 T, 8 kHz MAS, and 100 K.

[0051] Figure 9(B) shows the hydrated H + - 2D of sample D in form 29 Si{ 29 Solid-state NMR spectra mediated by Si} dipole. Spectra were obtained at 9.4 T, 8 kHz MAS, and 100 K.

[0052] Figure 10 It is hydrated H + - 2D of sample D in form 29 Si{ 29 SiJ-mediated solid-state NMR spectra. Spectra were obtained at 9.4 T, 8 kHz MAS, and 100 K.

[0053] Figure 11 It is hydrated H + - 2D of sample G in form 29 Si{ 29 SiJ-mediated solid-state NMR spectra. Spectra were obtained at 9.4 T, 8 kHz MAS, and 100 K.

[0054] definition :

[0055] As used herein, an entity “a” or “an” means one or more of that entity; for example, “a compound” means one or more compounds or at least one compound, unless otherwise stated. Therefore, the terms “a” (or “an”), “one or more” and “at least one” are used interchangeably herein.

[0056] As used herein, “the molar percentage of [X] calculated based on the total number of moles of [X] and [Y]”, for example in the context of nanoparticles, refers to a percentage calculated as follows:

[0057]

[0058] As used herein, the term “associated” means “equipped with,” “connected to,” or “in communication with,” for example, “electrically connected” or “fluidly connected” or connected in a manner that performs a function. As used herein, the term “associated” can mean directly or indirectly associated, i.e., through one or more other articles or elements.

[0059] As used herein, the term “AEI” refers to an AEI-type framework recognized by the Structural Committee of the International Zeolite Association (IZA), and the term “AEI zeolite” means an aluminosilicate with AEI as the main crystalline phase.

[0060] As used herein, the term "AFX" refers to the AFX-type framework recognized by the International Zeolite Association (IZA) Structural Committee, and the term "AFX zeolite" refers to silicon-aluminate phosphate-56.

[0061] As used herein, the term “AFT” refers to an AFT-type framework recognized by the International Zeolite Association (IZA) Structural Committee, and the term “AFT zeolite” refers to an AlPO4-52 catalyst.

[0062] As used herein, the term "BET surface area" has its usual meaning, referring to the Brunauer, Emmett, and Teller methods used to determine the surface area of ​​porous materials via N2 adsorption. Pore size and pore volume can also be determined using BET-type N2 adsorption or desorption experiments.

[0063] As used herein, the terms “catalyst” or “catalytic material” or “catalytic material” refer to materials that promote a reaction.

[0064] As used herein, the term "catalytic article" refers to an element used to facilitate a desired reaction. For example, a catalytic article may comprise a washcoat containing a catalytic substance (e.g., a catalyst composition) on a substrate (e.g., a honeycomb substrate).

[0065] As used in this article, the term “average particle size” refers to the particle characteristics that indicate the average diameter of the particles.

[0066] As used in this article, the term "material" refers to the elements, components, or substances that constitute or can be made into something.

[0067] As used herein, the term "nanoparticle" refers to a particle having at least one dimension with a length ranging from 1 nm to 999 nm.

[0068] As used herein, the term "nitrogen oxides" or "NO" refers to... x " " indicates nitrogen oxides.

[0069] As used herein, the term "particle size" refers to the smallest diameter sphere that would completely surround a particle, and the measurement pertains to a single particle, not an agglomeration of two or more particles. Particle size can be measured using laser scattering techniques, employing dispersions or dry powders, for example, according to ASTM Method D4464. The particle size of submicron-sized particles can also be measured using scanning electron microscopy (SEM) or transmission electron microscopy (TEM), or the particle size of particles with supports (micron-sized) can be measured using a particle size analyzer. In addition to TEM, carbon monoxide (CO) chemisorption can be used to determine the average PGM particle size. This technique does not distinguish between various PGM materials (e.g., Pt, Pd, etc., compared to XRD, TEM, and SEM) and only determines the average particle size. As used herein, the term "room temperature" or "ambient temperature" refers to a temperature in the range of 15°C to 25°C, such as, for example, 20°C to 25°C.

[0070] As used in this article, the term “basically” refers to a property with a statistical occurrence rate greater than 75%.

[0071] As used herein, the “support” in a catalytic material or catalyst-repaired substrate coating refers to a material that receives a catalyst (including, for example, precious metals, stabilizers, promoters, binders, etc.) by precipitation, association, dispersion, impregnation or other suitable methods.

[0072] As used herein, the term "selective catalytic reduction" (SCR) refers to a catalytic process that uses a nitrogen-containing reducing agent to reduce nitrogen oxides to nitrogen bis(N2). The SCR process utilizes ammonia to catalytically reduce nitrogen oxides to form nitrogen and water.

[0073] As used herein, the term "repair substrate coating" has its usual meaning in the art as a thin, adhesive coating of catalytic material or other material applied to a carrier substrate material (such as a honeycomb carrier member) that is porous enough to allow the flow of the treated gas stream. As understood in the art, a repair substrate coating is obtained from a dispersion of particles in a slurry, which is applied to a substrate, dried, and calcined to provide a porous repair substrate coating.

[0074] As used herein, the term "zeolite" refers to a specific example of a molecular sieve, comprising silicon and aluminum atoms. Zeolites are crystalline materials with fairly uniform pore sizes, the diameter of which varies depending on the type of zeolite and the type and amount of cations included in the zeolite lattice, ranging from approximately [missing value]. to Within the range.

[0075] In more specific implementations, references to the “aluminosilicate zeolite” framework type limit the material to molecular sieves that do not include phosphorus or other metals substituted within the framework. However, for clarity, as used herein, “aluminosilicate zeolite” does not include aluminophosphate materials such as SAPO, ALPO, and MeAPO, and the broader term “zeolite” is intended to include both aluminosilicates and aluminophosphates.

[0076] The zeolite CHA-framework type molecular sieve is also referred to as "CHA zeolite" in this article.

[0077] As used herein, the term "promoted" refers to a metallic component ("promoter metal") intentionally added to the molecular sieve material, as opposed to impurities inherent in the molecular sieve. Thus, a promoter is intentionally added to enhance the activity of the catalyst compared to a catalyst without an intentionally added promoter. To promote the selective catalytic reduction of nitrogen oxides in the presence of ammonia, in one or more embodiments, a suitable metal is independently exchanged into the molecular sieve. In some embodiments, other promoter metals that can be used to prepare the promoted zeolite of the disclosed catalyst composition include, but are not limited to, copper (Cu). In one or more embodiments, the promoter metal content, calculated in oxides, is independently in the range of about 0.01 wt% to about 15 wt%, about 0.5 wt% to about 12 wt%, or about 1.0 wt% to about 10 wt%, based on the total weight of the corresponding calcined zeolite (including the promoter metal) and based on a volatile-free record. In some embodiments, the promoter metal is copper or iron. In some embodiments, both copper and iron are present as promoter metals.

[0078] Zeolite catalyst

[0079] This disclosure relates to zeolite catalysts with aging durability and improved catalytic activity. For example, the zeolite catalyst includes a specific aluminum distribution, i.e., the positioning of two aluminum atoms at 3NN relative positions within the zeolite structure. The zeolite catalyst has two tetrahedral coordinated Al sites separated by two tetrahedral coordinated Si sites within the zeolite framework.

[0080] Exchangeable cations (such as H+) + Cu 2+ Zn 2+ The position and proximity of the Al heteroatoms depend on the position of the Al heteroatoms within the zeolite framework. For example, in an aluminosilicate framework, paired Al heteroatoms positioned close to each other as second or third nearest neighbors contribute to the stability of divalent exchangeable cations. This stability results in improved chemical reactivity. That is, in aluminosilicate zeolites H... + / Cu 2+ On the SSZ-13 catalyst, the Al content in the zeolite framework and, in particular, the distribution of paired Al sites affect the methanol-to-olefin conversion and the selectivity of the resulting products. This is shown in... Figure 5 middle, Figure 5 This is a diagram of the catalytic sites in aluminosilicate zeolite (SSZ-13).

[0081] In another example, NO in vehicle exhaust gas x Pollutants SCR into N2 and other products depend on the use of Cu 2+ Exchanged paired Al sites.

[0082] SAPO-34 and SSZ-13 are two catalysts with a CHA structure that have been extensively studied for methanol-to-olefins (MTO) reactions. SAPO-34 has been commercially available for MTO reactions, and SSZ-13 is a zeolite analog of SAPO-34 and exhibits selectivity for ethylene and propylene. Although SSZ-13 is a zeolite analog of SAPO-34, it exhibits different reaction behavior than SAPO-34, and this difference in reaction behavior is attributed to Brønsted acid (Brønsted acid). Brønsted acid sites are present in both SSZ-13 and SAPO-34, catalyzing the MTO reaction. A stronger Brønsted acid site is present in SSZ-13, leading to increased coking and deactivation. The deactivation and product selectivity of both CHA-type catalysts are attributed to the acid site density. Increasing the Si / Al ratio in the SSZ-13 sample increases catalyst stability and reaction time before deactivation.

[0083] Understanding and controlling the number and distribution of Al heteroatoms and associated cations to increase the number of paired framework Al sites improves the catalytic properties of zeolite catalysts. Cu-containing catalysts... 2+ An example of a catalyst with a “paired” Al framework structure is shown in Figure 6 Traditional methods for determining the number and distribution of Al heteroatoms include elemental analysis and 1D solid-state NMR. However, 1D solid-state NMR provides limited insights into Al localization because signal overlap makes it difficult to define connectivity between different sites.

[0084] This disclosure relates to zeolite catalysts with aging durability and improved catalytic activity. For example, the zeolite catalyst includes a specific aluminum distribution, i.e., the positioning of two aluminum atoms at 3NN relative positions in the zeolite structure. The zeolite catalyst has two tetrahedral Al sites separated by two tetrahedral Si sites.

[0085] This disclosure relates, for example, to paired Al atoms separated as second or third nearest tetrahedral sites within the SSZ-13 zeolite framework, resulting in improved catalytic properties. This disclosure enables the design of catalysts with targeted reaction properties, such as for reactions in which divalent or trivalent cations have a significant influence, including adsorption processes.

[0086] In some embodiments, this disclosure relates to zeolite catalysts having paired aluminum atoms, wherein the paired aluminum atoms are separated as second or third nearest neighbors in the zeolite structure. For example, in identifying different types of... 27 Al and 29 When working with Si materials, zeolite catalysts with paired aluminum atoms are of interest, primarily where the aluminum atom is the third nearest neighbor (3NN). In the 3NN distribution, two tetrahedral Al sites are separated by two tetrahedral Si sites.

[0087] In some embodiments, the zeolite catalysts of this disclosure have 8-membered ring pore openings and bi-6-ring secondary building units, particularly those with a cage-like structure, making them suitable for use as SCR catalysts. In some embodiments, the zeolite catalyst of this disclosure is chalcogenide (CHA), a microporous zeolite with 8-membered ring pore openings (approximately 3.8 Å) that are accessible through its 3D pores. The cage-like structure is generated by the bi-6-ring building units linked by 4-membered rings.

[0088] In some embodiments, this disclosure relates to aluminosilicate zeolites, aluminosilicate zeolites having bis-6-ring (D6R) building blocks, microporous (8-membered ring pore-opening) aluminosilicate zeolites, and chalcogenide zeolites. In some embodiments, the zeolite catalyst having a 3NN distribution of Al atoms may also contain a metal (such as copper), which may be introduced after the zeolite synthesis itself. In some embodiments, Cu metal is also introduced during the zeolite synthesis.

[0089] In some embodiments, this disclosure relates to catalytic compositions comprising aluminosilicates having paired aluminum atoms, wherein the paired aluminum atoms are separated as second or third nearest neighbors in the aluminosilicate structure.

[0090] In some embodiments, the zeolite catalyst of this disclosure contains a SiO2 / Al2O3 (SAR) ratio in the range of 8-40. In some embodiments, the zeolite catalyst of this disclosure contains a SiO2 / Al2O3 (SAR) ratio in the range of 10-30. In some embodiments, the zeolite catalyst of this disclosure contains a SiO2 / Al2O3 (SAR) ratio in the range of 11-25.

[0091] In some embodiments, the zeolite catalyst of this disclosure contains a Cu content corresponding to a Cu / Al ratio of about 0.2 to about 0.5. In some embodiments, the zeolite catalyst of this disclosure contains a Cu content corresponding to a Cu / Al ratio of about 0.25 to about 0.45. In some embodiments, the zeolite catalyst of this disclosure contains a Cu content corresponding to a Cu / Al ratio of about 0.3 to about 0.4.

[0092] The catalyst disclosed herein is applicable to a wide range of heteroatom-containing silicate materials, such as nanoporous aluminosilicates, borosilicates, or gallium silicates used in catalysis or separation.

[0093] Zeolites with a 3NN aluminum distribution exhibit improved NO production under selective catalytic reduction (SCR) conditions after the introduction of metals (such as Cu). x Conversion rate. For example, in some embodiments, the zeolite catalysts of this disclosure exhibit aging durability and high or improved catalytic activity compared to zeolites without 3NN aluminum distribution.

[0094] In some embodiments, the zeolite catalyst of this disclosure exhibits 10% higher NO content after hydrothermal aging at 800°C. x Conversion rate (at 800°C for 16 hours in the presence of 10% steam and balance air, with the exhaust gas having a conversion rate of 80,000 h under pseudo-steady-state conditions) -1 The mixture is based on a volume hourly space velocity and contains 500 ppm NO, 500 ppm NH3, 10% O2, 5% H2O, and the balance N2. In some embodiments, after hydrothermal aging at 850°C (16 hours), the zeolite catalyst of this disclosure provides a minimum of 50% NO. x Conversion rate (under the same conditions as above).

[0095] In some embodiments, the zeolite catalyst of this disclosure with a 3NN aluminum distribution exhibits improved catalytic performance for methanol dimerization at 20 μL. 13 In a batch reaction of CH3OH over 50 mg of dehydration catalyst, at 125 °C or 150 °C under an argon inert atmosphere and ambient pressure, the conversion rate was approximately 10% higher than that of zeolite without 3NN sites. This was achieved through in-situ... 13 C NMR was used to track the conversion rate of methanol to dimethyl ether.

[0096] Zeolite Synthesis

[0097] This disclosure relates to zeolite catalysts exhibiting aging durability and improved catalytic activity. For example, the zeolite catalyst includes a specific aluminum distribution, i.e., the positioning of two aluminum atoms at 3NN relative positions in the zeolite structure. The zeolite catalyst has two tetrahedral Al sites separated by two tetrahedral Si sites. This disclosure also relates to processes and methods for characterizing and using these zeolite catalysts.

[0098] In some embodiments, the zeolite catalysts of this disclosure are prepared via a series of synthetic methods. In some embodiments, the aluminum source is a precursor zeolite, such as a zeolite having an octahedral zeolite (FAU) structure. In some embodiments, the FAU source comprises Na-Y or various dealuminated forms of zeolite Y. In some embodiments, other zeolite precursors may also be used. In some embodiments, the aluminum source may be an aluminum salt or complex, such as aluminum isopropoxide, aluminum sulfate, and related compounds.

[0099] In some embodiments, this disclosure also relates to methods for forming zeolite catalysts. For example, one method includes forming a reaction mixture comprising at least one alumina source including a zeolite (typically a zeolite with a FAU framework), at least one silica source (such as a source comprising an alkali metal silicate solution and / or colloidal silica), at least one organic structure directing agent, and optionally a second alkali metal cation source to increase the alkali metal content of the reaction mixture. The reaction mixture is typically provided under alkaline aqueous conditions. In some embodiments, the molar ratio of the alkali metal to Si combination (M / Si, where M is the number of moles of the alkali metal) and the molar ratio of the organic structure directing agent to Si (R / Si, where R is the number of moles of the organic structure directing agent) are greater than the molar ratio of hydroxide ions to Si (OH / Si). In other words, the molar ratio of the combination M / Si + R / Si is greater than the molar ratio of OH / Si. For the bulk reaction mixture, the SAR range is typically from about 25 to about 35.

[0100] In some implementations, the combined M / Si+R / Si ratio is greater than about 0.75, or greater than about 0.80, or greater than about 0.82 or greater than about 0.85, with example ranges from about 0.75 to about 0.95, or about 0.80 to about 0.95, or about 0.85 to about 0.95.

[0101] In some implementations, the OH / Si molar ratio is less than about 0.7, or less than about 0.65, or less than about 0.6, or less than about 0.55, with example ranges from about 0.3 to about 0.7 or from about 0.4 to about 0.65.

[0102] In some embodiments, the individual M / Si molar ratio is at least about 0.4, or at least about 0.5, or at least about 0.6, or at least about 0.7, or at least about 0.8, with example ranges from about 0.4 to about 1.2, or about 0.6 to about 1.0, or about 0.7 to about 0.9. The alkali metal can be, for example, lithium, sodium, potassium, rubidium, cesium, or francium. In some embodiments, the alkali metal is sodium or potassium.

[0103] In some implementations, the individual R / Si molar ratio is less than about 0.12, or less than about 0.11, or less than about 0.10, or less than about 0.08, or less than about 0.06, with example ranges from about 0.04 to about 0.12, or from about 0.06 to about 0.10.

[0104] The reaction mixture can also be characterized by the molar ratio of water to Si (H2O / Si), which is typically in the range of about 12 to about 40.

[0105] The alkali metal silicate solution used in the reaction mixture provides all the alkali metal content required to achieve the above ratio. However, the alkali metal content of the reaction mixture may optionally be supplemented with a second alkali metal cation source, examples of which include alkali metal sulfates (e.g., Na₂SO₄), alkali metal acetates (e.g., sodium acetate), and alkali metal bromides (e.g., sodium bromide). If desired, in some embodiments, the alkali metal silicate solution may be supplemented with other silica sources, such as colloidal silica, fuming silica, tetraethyl orthosilicate (TEOS), and combinations thereof, or may be replaced by such other silica sources.

[0106] The zeolite used as the alumina source can vary and includes a wide range of zeolite materials known in the art, particularly various aluminosilicate zeolites. In some embodiments, a zeolite with a FAU crystal structure is used, which is formed by a 12-ring structure and has approximately The channels. Examples of such zeolites include octahedral zeolite, zeolite X, zeolite Y, LZ-210, and SAPO-37. These zeolites are characterized by a 3D porous structure with pores extending perpendicularly to each other in the x, y, and z planes, and secondary building blocks 4, 6, and 6-6. Examples of bulk FAU zeolite materials have a SAR range of about 3 to about 6, typically having a cell size range of 24.35 to 24.65, as determined by XRD. Zeolite Y is particularly useful for certain embodiments of the invention. FAU zeolites are typically in alkali metal form, such as Na... + In some embodiments, FAU zeolite is in sodium form and contains about 2.5% to 13% Na₂O by weight.

[0107] A typical organic structure-directing agent used in this synthesis is adamantyltrimethylammonium hydroxide, although other amines and / or quaternary ammonium salts can be substituted or added. Examples include quaternary ammonium cations having substituents selected from the group consisting of alkyl, adamantyl, cyclohexyl, aromatic groups, and combinations thereof. Other examples of organic structure-directing agents include cyclohexyltrimethylammonium, benzyltrimethylammonium, and dimethylpiperidine. hydroxide.

[0108] Hydroxide ions are the only essential mineralizing agent required in the reaction mixture, and the amount of hydroxide ions required to achieve the above ratio can be provided solely by the alkali metal silicate solution, and to a lesser extent by an organic structure-directing agent source. If desired, the hydroxide ion content can be supplemented with additional hydroxide ion sources (such as NaOH or KOH).

[0109] The reaction mixture can be characterized in terms of solids content, expressed as a weight percentage of silicon dioxide (SiO2) and aluminum oxide (Al2O3). The solids content can vary, with examples ranging from about 5% to about 25% or from about 8% to about 20%.

[0110] The reaction mixture is heated in a pressure vessel under stirring to produce the desired CHA crystals. Typical reaction temperatures range from about 100°C to about 180°C, for example from about 120°C to about 160°C, with corresponding autogenous pressure. Typical reaction times range from about 30 hours to about 3 days. Optionally, the product can be centrifuged. Organic additives can be used to aid in the handling and separation of solid products. Spray drying is an optional step in product processing.

[0111] In some implementations, zeolites with a MOR crystal framework are formed as intermediates or as byproducts. The MOR phase may contain an organic template.

[0112] Solid zeolite products are heat-treated or calcined in air or nitrogen. Typical calcination temperatures are from about 400°C to about 850°C (e.g., from about 500°C to about 700°C), for a period of 1 to 10 hours. After initial calcination, the CHA zeolite products are primarily in alkali metal form (e.g., Na). + (Form). Optionally, single or multiple ammonia ion exchanges can be used to generate NH4. + The zeolite is in the form of H, which is optionally further calcined to form H + form.

[0113] In some embodiments, the CHA zeolite is further ion-exchanged with a promoter metal to form a metal-promoted zeolite catalyst. For example, copper or iron can undergo ion exchange to form Cu-CHA or Fe-CHA. When copper acetate is used, in some embodiments, the copper concentration of the liquid copper solution used for copper ion exchange is in the range of about 0.01 mol to about 0.4 mol, and further, for example, in the range of about 0.05 mol to about 0.3 mol.

[0114] In some embodiments, the CHA zeolite crystals produced by crystallization may be about 80% to about 99% crystallized or about 90% to about 97% crystallized.

[0115] In some embodiments, the CHA zeolite product is characterized by a combination of a relatively low mesopore surface area (MSA) and a zeolite surface area (ZSA) that provides good catalytic performance. In some embodiments, the MSA of the CHA zeolite product is less than about 25 μm. 2 / g or less than about 10m 2 / g (e.g., about 5m) 2 / g to approximately 25m 2 / g). The ZSA of CHA zeolite products is typically at least about 400m. 2 / g, or at least about 450m 2 / g, or at least about 500m 2 / g, the example ZSA range is approximately 400m 2 / g to approximately 600m 2 / g or approximately 450mg 2 / g to approximately 600m 2 / g. Pore volume and surface area characteristics were determined by nitrogen adsorption (BET surface area method). Mesoporous and zeolite (microporous) surface areas were determined by N2-adsorption porosity determination on a Micromeritics Tristar 3000 series instrument according to ISO 9277 method. Samples were degassed on a Micromeritics SmartPrep degasser for a total of 6 hours (2 hours to 300°C, then held at 300°C for 4 hours under a dry nitrogen flow). Nitrogen BET surface areas were determined using five partial pressure points between 0.08 and 0.20. Zeolite and matrix surface areas were determined using the same five partial pressure points and calculated using Harkins and Jura t-plots. Diameters greater than... The pores are believed to contribute to the matrix surface area.

[0116] CHA zeolite products are also characterized by relatively low normalized ZSA loss after treatment with NH4F solution, such as after treatment with 40% wt% NH4F solution at 50°C with stirring at 350 rpm and ultrasonic treatment (35 kHz, 90 W) for 20 minutes. + The zeolite material, after being dried and calcined at 450°C for 6 hours, has a loss of less than about 60% (or less than about 50%). A formula for calculating the normalized ZSA loss is given in U.S. Patent No. 11,267,717.

[0117] In some implementations, such as by using diffuse reflectance infrared Fourier transform (DRIFT) spectral comparison at 3742 cm⁻¹ -1 The integrated intensity of the peak (peak X) at 3609 cm⁻¹ is similar to that at the center. -1 Estimated by the integrated intensity of the peak (peak Y), CHA zeolite products typically exhibit relatively few surface silanols compared to bridged silanols (Brønsted sites). DRIFTS measurements were performed on a ThermoNicolet in a Harrick environmental chamber equipped with a mercury-tellurium-cadmium (MCT) detector and a ZnSe window. The sample was ground into a fine powder using a mortar and pestle and then filled into sample cups. The sample powder was first dehydrated in flowing Ar at 400°C for 1 hour at a flow rate of 40 ml / min, and then cooled to 30°C. The spectrum of the sample was acquired using KBr as a reference. In some embodiments, the surface silanol fraction (X / Y peak ratio) of the CHA zeolite product is less than about 0.04 or less than about 0.03.

[0118] The CHA zeolite products produced by this method typically have an average crystal size ranging from about 3 μm, or from about 200 nm to about 3 μm, or from about 500 nm to about 2 μm, or from about 800 nm to about 1.5 μm. The average crystal size can be measured, for example, using a microscope, such as a scanning electron microscope (SEM).

[0119] CHA zeolite products can also be characterized by the presence of H... + The amount of non-framed aluminum (EFAl) in the form of, which is determined by... 27 The percentage of total aluminum as determined by Al NMR. H + Zeolite in form via Na + The form is obtained by ammonium exchange with NH4NO3 followed by calcination at 450°C (6 hours). In some embodiments, the CHA zeolite product has less than about 20% or less than about 18%, such as about 5% to about 18% (or about 5% to about 15%) of EFAl. The percentage of extra-frame aluminum (EFAl) is defined as the integrated peak intensity in the NMR spectrum measured at 14.1T in the frequency range of 20 ppm to -30 ppm.

[0120] Identification of zeolite catalysts with third nearest neighbor (3NN) paired aluminum atoms

[0121] A method for characterizing the covalent bond connectivity between J-coupled heteroatoms in a zeolite material, the method comprising: synthesizing a zeolite material wherein trimethyladamantyl ammonium hydroxide (TMAdaOH) is used as an organic structure-directing agent (OSDA) for the zeolite material. The crystallization of the zeolite can be carried out using a mineralizing agent, a Na+ source, an Al source, and / or a Si source. The mineralizing agent can be sodium hydroxide (NaOH). The Na+ source can be selected from NaOH and / or Na2SO4. The Al source can be selected from Na-FAU and / or aluminum isopropoxide. The Si source can be selected from colloidal silica and / or sodium silicate solution. The zeolite material product is then separated by filtration, dried, and calcined at 540°C for 6 hours to produce Na+. The zeolite material is characterized by XRD and N2- physisorption. After calcination, single or multiple NH4+ ions are added. + Exchange until the Na₂O content reaches <500 ppm. NH₄ + The zeolite material in this form is then calcined at 450°C for 6 hours to produce H. + The form was then analyzed by solid-state NMR.

[0122] Can be achieved through 2D 27 Al{ 29 Si}J-HMQC NMR and 2D 29 Si{ 29 SiJ-mediated SQ-DQ NMR spectroscopy (both types were obtained at 9.4 T, 8 kHz MAS, and 100 K) was used to assess the distribution of Al materials (including paired 2NN and 3NNAl materials) within the zeolite framework.

[0123] The correlation between NMR spectra and aluminum (Al) sites in zeolite materials was established by analyzing 1D and 2D solid-state NMR spectra. From the 1D solid-state 1D NMR of zeolite, it can be seen that... 29 Si NMR spectra in Q 4 The region exhibits at -105ppm, -110ppm, -113ppm, -115ppm and -119ppm. 29 Si signal. Cross-linked Si silanol material in Q 3 The region produces at -97ppm, -99ppm and -101ppm. 29 Si signal. Based on previous 2D comparisons with calcined zeolite. 29 Si{ 29 Si} and 29 Si{ 1 ¹H NMR analysis, analysis of average -TOT bond angle and TO bond length and 29A comparison of Si chemical shift values ​​and existing literature, and the allocation of 2D 27 Al{ 29 Correlation in Si}J-mediated spectra 27 Al- 29 Si signal. Related 27 Al and 29 Si signal in 2D 27 Al{ 29 SiJ-mediated HMQC spectra range from -107 ppm to -105 ppm and from -101 ppm to -99 ppm. 29 Analysis at the Si displacement. This correlation can also be obtained by analyzing Q. 4 (1Al) 29 The Si chemical shift δ is calculated by relating it to the average -TOT bond angle θ'.

[0124] A method for characterizing the covalent bond connectivity between J-coupled heteroatoms in zeolite materials, wherein the synthesis of the zeolite materials includes the use of trimethyladamantyl ammonium hydroxide (TMAdaOH) as an organic structure directing agent (OSDA). The synthesis also includes crystallizing a silicate solution and Na-FAU; and neutralizing excess substances with H₂SO₄. 29 Si-O- 29 Examples of the correlation between Si connectivity differences and 2D NMR spectra are shown in Figures 7(A) and 7(B).

[0125] A method for characterizing the covalent bond connectivity between J-coupled heteroatom nuclei in zeolite materials, wherein the NMR spectrum is a 2D solid-state NMR spectrum.

[0126] A method for characterizing the covalent bond connectivity between J-coupled heteroatom nuclei in zeolite materials, wherein the NMR spectrum is HQMC NMR spectrum.

[0127] A method for characterizing the covalent bond connectivity between J-coupled heteroatomic nuclei in a zeolite material includes a zeolite catalytic composition having paired aluminum atoms within a framework, wherein the paired aluminum atoms are separated as the second or third nearest T-site in the zeolite structure.

[0128] Methods for characterizing the covalent bond connectivity between J-coupled heteroatom nuclei in zeolite materials include methods for using chabazite catalysts.

[0129] Methods for characterizing the covalent bond connectivity between J-coupled heteroatom nuclei in zeolite materials include the synthesis of chabazite zeolite catalysts using Na-FAU.

[0130] Methods for characterizing the covalent bond connectivity between J-coupled heteroatom nuclei in CHA zeolite materials include, where when using 2D 29 Si{29 When SiJ-mediated NMR measurements are performed using 2D measurements, the catalyst composition is characterized in the range of -104 ppm to -108 ppm in the single quantum (SQ) dimension and in the range of -208 ppm to -212 ppm in the double quantum (DQ) dimension.

[0131] Methods for characterizing the covalent bond connectivity between J-coupled heteroatomic nuclei in CHA zeolite materials include catalyst compositions that produce NMR spectral features, wherein the peak intensities are approximately 10% to 50% higher than those of catalyst compositions in which paired aluminum atoms are not third nearest neighbors (3NN).

[0132] Methods for characterizing the covalent bond connectivity between J-coupled heteroatom nuclei in CHA zeolite materials include, where when using 2D 27 Al{ 29 During Si}J-HMQC NMR measurements, the catalyst composition was generated in 29 Si dimension in the range of -98ppm to -100ppm and in 27 NMR spectral characteristics in the Al dimension in the range of 55 ppm to 59 ppm.

[0133] Implementation Plan

[0134] Without limitation, some embodiments of this disclosure include:

[0135] Implementation Scheme 1. A zeolite catalyst having paired aluminum atoms, wherein the paired aluminum atoms are the third nearest neighbors (3NN) in the zeolite structure, and wherein the zeolite catalyst has aging durability, improved catalytic activity, or a combination thereof.

[0136] Implementation Scheme 2. The zeolite catalyst according to Implementation Scheme 1, wherein the zeolite catalyst is a CHA zeolite catalyst.

[0137] Implementation Scheme 3. The zeolite catalyst according to Implementation Scheme 2, wherein the CHA zeolite catalyst is a copper-CHA catalyst.

[0138] Implementation Scheme 4. The catalyst composition according to Implementation Scheme 1, wherein the zeolite is a microporous zeolite.

[0139] Implementation Scheme 5. The catalyst composition according to Implementation Scheme 4, wherein the microporous zeolite is AEI.

[0140] Implementation Scheme 6. The catalyst composition according to Implementation Scheme 4, wherein the microporous zeolite is AFX.

[0141] Implementation Scheme 7. The catalyst composition according to Implementation Scheme 4, wherein the microporous zeolite is AFT.

[0142] Implementation Scheme 8. The zeolite catalyst according to Implementation Scheme 1, wherein when 2D is used 29 Si{ 29 During SiJ-mediated NMR measurements, this zeolite catalyst exhibited NMR properties ranging from -104 ppm to -108 ppm in the single quantum (SQ) dimension and from -208 ppm to -212 ppm in the double quantum (DQ) dimension. 29 Si NMR characteristics.

[0143] Implementation Scheme 9. The zeolite catalyst according to Implementation Scheme 1, wherein when 2D is used 27 Al{ 29 When measured by Si}J-HMQCNMR, this zeolite catalyst exhibits [the following properties / effects]: 29 Si dimension in the range of -98ppm to -100ppm and in 27 NMR characteristics in the Al dimension in the range of 55 ppm to 59 ppm.

[0144] Implementation Scheme 10. The zeolite catalyst according to Implementation Scheme 1, wherein the aging durability is achieved after hydrothermal aging at 800°C, and the zeolite catalyst exhibits 10% higher NO content compared to zeolite without the 3NN site. x Conversion rate.

[0145] Implementation Scheme 11. The zeolite catalyst according to Implementation Scheme 1, wherein the aging durability is achieved after hydrothermal aging at 850°C, the zeolite catalyst exhibits at least 50% NO content. x Conversion rate.

[0146] Implementation Scheme 12. The zeolite catalyst according to Implementation Scheme 1, wherein the zeolite catalyst has an improved catalytic activity for methanol dimerization with a conversion rate approximately 10% higher than that of zeolites without the 3NN site.

[0147] Implementation Scheme 13. The zeolite catalyst according to Implementation Scheme 1, wherein the zeolite catalyst has a SiO2 / Al2O3 ratio (SAR) selected from 8-40, 10-30 and 11-25.

[0148] Implementation Scheme 14. The zeolite catalyst according to Implementation Scheme 1, wherein the zeolite catalyst further comprises copper (Cu), wherein the Cu content corresponds to a Cu / Al ratio selected from 0.2 to 0.5, 0.25 to 0.45 and 0.3 to 0.4.

[0149] Implementation Scheme 15. A catalyst article for effectively reducing nitrogen oxides (NOx) from lean-burn engine exhaust, the catalyst article comprising a substrate support having a selective catalytic reduction (SCR) catalyst according to Implementation Scheme 1.

[0150] Implementation Scheme 16. The catalyst article according to Implementation Scheme 15, wherein the substrate support is a honeycomb substrate and optionally made of metal or ceramic.

[0151] Implementation Scheme 17. The catalyst product according to Implementation Scheme 15, wherein the honeycomb substrate carrier is a flow-through substrate or a wall-flow filter.

[0152] Implementation Scheme 18. A waste gas treatment system, the waste gas treatment system comprising:

[0153] A lean-burn engine that produces exhaust gas flow;

[0154] and

[0155] According to embodiment 15, the catalyst article is located downstream of the lean-burn engine and is in fluid communication with the exhaust gas flow.

[0156] Implementation Scheme 19. The waste gas treatment system according to Implementation Scheme 18, further comprising one or more of the following:

[0157] a. Diesel engine oxidation catalyst (DOC), which is located upstream of the catalyst product;

[0158] b. A smoke filter located upstream of the catalyst product;

[0159] and

[0160] c. Ammonia oxidation catalyst (AMOX), which is located downstream of the catalyst product.

[0161] Implementation Scheme 20. A method for preparing a selective catalytic reduction (SCR) catalyst, the method comprising:

[0162] (a) Preparation of a catalyst according to any one of embodiments 1 to 14;

[0163] (b) Apply the catalyst as a coating onto a ceramic or metal honeycomb substrate;

[0164] (d) Dry the coated material;

[0165] (e) Calcine the coated monolith at a temperature in the range of 400°C to 800°C.

[0166] Implementation Scheme 21. The zeolite catalyst according to Implementation Scheme 1, wherein the aluminum source is Na-FAU.

[0167] Implementation Scheme 22. The zeolite catalyst according to Implementation Scheme 1, wherein the aluminum source is aluminum isopropoxide.

[0168] Implementation Scheme 23. The zeolite catalyst according to Implementation Scheme 1, wherein the aluminum source is H-FAU.

[0169] Implementation Scheme 24. The zeolite catalyst according to Implementation Scheme 1, wherein the silicon source is sodium silicate.

[0170] Implementation Scheme 25. The zeolite catalyst according to Implementation Scheme 1, wherein the silicon source is colloidal silicon dioxide.

[0171] Implementation Scheme 26. The zeolite catalyst according to Implementation Scheme 1, wherein the silicon source is H-FAU.

[0172] Implementation Scheme 27. The zeolite catalyst according to Implementation Scheme 1, wherein the Na / Si ratio is 0.818.

[0173] Implementation Scheme 28. The zeolite catalyst according to Implementation Scheme 1, wherein the Na / Si ratio is 0.785.

[0174] Implementation Scheme 29. The zeolite catalyst according to Implementation Scheme 1, wherein the Na / Si ratio is 0.194.

[0175] Implementation Scheme 30. The zeolite catalyst according to Implementation Scheme 1, wherein the OH / Si ratio is 0.506.

[0176] Implementation Scheme 31. The zeolite catalyst according to Implementation Scheme 1, wherein the OH / Si ratio is 0.675.

[0177] Implementation Scheme 31. The zeolite catalyst according to Implementation Scheme 1, wherein the OH / Si ratio is 0.418.

[0178] If one, more than one, or all of the group members are present in, used in, or otherwise associated with a given product or process, then the inclusion of "or" or "and / or" among at least one member of the group in the claim or description is considered satisfied, unless otherwise indicated or otherwise apparent from the context. This disclosure includes embodiments in which exactly one member of the group is present in, used in, or otherwise associated with a given product or process. This disclosure also includes embodiments in which more than one or all of the group members are present in, used in, or otherwise associated with a given product or process.

[0179] Furthermore, this disclosure covers all variations, combinations, and substitutions in which at least one limitation, element, clause, and descriptive term from at least one of the listed claims is incorporated into another claim. For example, any claim dependent on another claim may be modified to include at least one limitation found in any other claim dependent on the same basic claim. Where elements are presented in list form (such as in Markush group format), each subgroup of elements is also disclosed, and any element may be removed from that group. It should be understood that, in general, where an embodiment of this disclosure or an aspect thereof is referred to as including a particular element and / or feature, embodiments of this disclosure or an aspect thereof consist of or are substantially composed of such elements and / or features. For simplicity, these embodiments are not specifically described herein in the same words. Where a range is given (such as, for example, from [X] to [Y]), endpoints (such as, for example, [X] and [Y] in the phrase “from [X] to [Y]”) are included, unless otherwise indicated. Furthermore, unless otherwise indicated or clearly apparent from the context and understanding of one of ordinary skill in the art, values ​​expressed as ranges may be assumed to be any specific value or subrange within the range described in different embodiments of this disclosure, up to one-tenth of the lower limit unit of the range, unless the context otherwise clearly indicates otherwise.

[0180] Using only conventional experiments, those skilled in the art will recognize or be able to identify many equivalents of the specific embodiments of the disclosure described herein. Such equivalents are intended to be covered by the appended claims. Example

[0181] The following examples are intended to be illustrative and are not intended to limit the scope of this disclosure in any way.

[0182] Example 1: Measurement of the catalytic properties of samples A, B, C, D, and G

[0183] Sample A is a CHA zeolite synthesized using trimethyladamantyl ammonium hydroxide (TMAdaOH) as the organic structure-directing agent (OSDA) for CHA. Crystallization of Sample A utilized sodium silicate solution (SiO2 / Na2O = 2.6, 37% solids content) and Na-FAU (SiO2 / Al2O3 = 5.1) as the Si and Al sources, respectively. The desired OH / Si ratio was obtained by neutralizing excess OH with H2SO4. Assuming the Na... + The OH / SiO2 ratio is calculated by using a 1:1 ratio between OH and SiO2.

[0184] Sample B (also a CHA zeolite) was synthesized using trimethyladamantyl ammonium hydroxide (TMAdaOH) as the organic structure directing agent (OSDA) for CHA. For the crystallization of sample B, sodium hydroxide (NaOH) was used as the mineralizing agent and the only Na in the gel. + The source, and aluminum isopropoxide and colloidal silica (40 wt% SiO2) 2 They were used as Si and Al sources, respectively.

[0185] After crystallization, sample A and sample B were separated by filtration, dried, and calcined at 540°C for 6 hours to produce Na+.

[0186] After calcination, perform one or more NH4 reactions. + Exchange until the Na₂O content reaches <500 ppm. NH₄ + The form was further calcined at 450℃ for 6 hours to produce H. + form.

[0187] NMR is used to determine the conversion of methanol to dimethyl ether over time. In some embodiments, in-situ NMR is used. 13 C10 NMR was used to measure the conversion of methanol to dimethyl ether in a batch reactor at 125 °C and 150 °C to determine the dehydration H2O. + Catalytic properties of samples A and B in the form of... Figure 1A As shown, representative time analysis 13 Direct-excited NMR spectroscopy at 47 ppm to 54 ppm showed a range of 47 ppm to 54 ppm. 13 The C signal corresponds to methanol adsorbed in different local environments. Spectra were obtained at 11.7 T and 5 kHz MAS. Figure 1A It also displays NMR spectra, in which 13 The C signal is in the range of 56 ppm to 64 ppm, which corresponds to dimethyl ether.

[0188] For the reactions on the two samples at 125°C and 150°C, the methanol conversion over time was shown... Figure 1B To determine the methanol conversion rate over time under different conditions, the spectral intensities of adsorbed methanol and dimethyl ether were individually integrated. At both temperatures, the methanol conversion rate on sample A was significantly higher than that on sample B.

[0189] Samples C, D, and G are CHA zeolites synthesized using trimethyladamantyl ammonium hydroxide (TMAdaOH) as the organic structure-directing agent (OSDA) for CHA. The Si and Al sources for sample C are sodium silicate and Na-FAU, respectively. The molar ratios of sample C are as follows: Na / Si = 0.785, R / Si = 0.03, OH / Si = 0.625, and H₂O / Si = 33.2. Crystallization of sample C was carried out at 140 °C for 72 hours.

[0190] The Si source and Al source for sample D are colloidal silica and aluminum isopropoxide, respectively. The molar ratios of sample D are as follows: Na / Si = 0.207, R / Si = 0.108, OH / Si = 0.315, and H₂O / Si = 23.6. Crystallization of sample D was carried out at 160 °C for 45 hours.

[0191] The Si and Al sources for sample G were H-FAU. The molar ratios of sample G were as follows: Na / Si = 0.194, K / Si = 0.124, R / Si = 0.100, OH / Si = 0.418, and H₂O / Si = 22.2. Crystallization of sample G was carried out at 150 °C for 24 hours.

[0192] Samples C, D, and G were calcined at 540°C for 6 hours under a flowing dry air stream. Following the first calcination step, unlike samples A and B, samples C, D, and G underwent two ammonium exchange steps. These two ammonium exchange steps were followed by a second calcination step at 450°C for 6 hours under a flowing dry air stream. Cu ions were introduced into the H₂O. + A target CuO loading of 6.8 wt% to 7.2 wt% was obtained in the form of zeolite. A catalytic coating containing Cu-CHA, zirconium oxide, and pseudoboehmite binder was applied to the sample via a repair substrate coating process. The coated substrate was dried at 110°C to 150°C and calcined at approximately 550°C for 1 hour. The coating process yielded 2.2 g / in 3 The catalyst was supported on a substrate containing 5% zirconium oxide and 5% alumina binder. The coated substrate was hydrothermally aged at 800°C for 16 hours in the presence of 10% H2O / air.

[0193] In a laboratory reactor, a gas mixture of 500 ppm NO, 525 ppm NH3, 10% O2, 10% H2O, and the balance N2 was heated from 200 °C to 550 °C at a temperature ramp of 5 °C / min. Under pseudo-steady-state conditions, the temperature was increased for 80,000 h. -1 NO was measured in a solid material aged at 800°C for 16 hours, based on the gas hourly space velocity. x Conversion rate. Figure 1C and Figure 1DNO x Conversion and N2O selectivity data indicate that these performance characteristics of interest are directly dependent on the amount of 3NN paired Al sites in the three samples. The NO content of samples A and B... x The conversion rate was previously determined in U.S. Patent No. 11,267,717 (e.g.) Figure 5 Samples F and C are shown in the figure. Figure 1E middle.

[0194] Sample G, exhibiting significantly higher NO levels at paired Al sites (3NN) than both samples C and D, had the highest NO content across the entire temperature range. x The conversion rate was the lowest among the three samples, and the N2O selectivity was the lowest across the entire temperature range. Sample D, exhibiting the lowest third-nearest-neighbor Al site configuration among the three samples, also showed the lowest NO content among the three materials, except at 550 °C. x Highest conversion rate and highest N2O selectivity across the entire temperature range.

[0195] Samples A, B, C, D, and G can be divided into two main groups. Sample A was synthesized using silicate solution and Na-FAU as the Si source and Al source, respectively, while sample B was synthesized using colloidal silica and aluminum isopropoxide. Samples A and B were exchanged with ammonium ions only once. Samples C and D had the same starting materials as samples A and B, respectively. Sample G was synthesized using H-FAU as the Si source and aluminum source. Samples C, D, and G were exchanged with ammonium ions twice. Among samples A and B, sample A showed better performance, as shown in... Figure 1A and Figure 1B The methanol conversion rate test results in samples C, D, and G indicate this. Figure 1C and Figure 1D As shown, samples C and G in NO x Higher 3NN paired Al sites and better performance were observed in conversion rate and N2O selectivity tests. Figures 1A to 1E The results show that, among samples A, B, C, D, and G, samples A, C, and G possess catalytic performance and unique NMR characteristics according to this disclosure. The table below (Table 1) shows data for samples A, C, and G, their starting materials, and their Na / Si and OH / Si ratios.

[0196] Table 1. Synthesis information for samples A, B, C, D, and G

[0197] sample AI Source Main Si source Na / Si K / Si OH / Si Sample A Na-FAU Sodium silicate 0.818 0 0.506 Sample B Aluminum isopropoxide colloidal silica 0.128 0 0.198 Sample C Na-FAU Sodium silicate 0.785 0 0.675 Sample D Aluminum isopropoxide colloidal silica 0.207 0 0.315 Sample G H-FAU (SAR=12) H-FAU (SAR=12) 0.194 0.124 0.418

[0198] Example 2: Measurement of reaction properties via solid-state NMR

[0199] Solid-state NMR on aluminosilicate zeolites 27 Al and29 The local chemical environment of Si atoms is sensitive and can be used to determine reaction properties. In some embodiments, Figure 2A H shows approximately the same SiO2 / Al2O3 ratio (SAR). + - One-dimensional (1D) samples A and B in the form of... 29 Si direct-excited NMR spectra were obtained at 18.8 T, 20 kHz MAS, and 298 K. Each sample exhibited values ​​corresponding to Q at -111 ppm and -105 ppm. - (0Al) and Q 4 Two strong signals in the (1Al) region. The Q values ​​of samples A and B. 4 The relative intensities of the signals (0Al) and Q4(1Al) are similar, which corresponds to samples A and B with similar SAR values.

[0200] Figure 2B H was displayed + - 1D of sample A and sample B in form 27 Al direct-excited NMR spectra. The two spectra stand out at 59 ppm. 27 The Al signal corresponds to tetracoordinated Al atoms. This is consistent with their binding within the aluminosilicate zeolite framework, while the weak signal near -1 ppm in each spectrum corresponds to hexacoordinated Al atoms outside the framework. In these 1D... 27 No significant differences were observed in the AlNMR spectra.

[0201] Example 3: Measurement of reaction properties using multidimensional NMR technology

[0202] Multidimensional NMR, by probing nanoscale through-bond and through-space interactions between NMR active nuclei, provides more detailed insights into the local chemical environment of materials. For example, two-dimensional (2D)J-mediated... 29 Si{ 29 Single-quantum (SQ)-dual-quantum (DQ) NMR correlation spectroscopy of Si can be used to detect Si aluminosilicate materials. 29 Si-O- 29 Si connectivity.

[0203] In some implementation schemes, Figure 3A and Figure 3B H was displayed + - 2D of sample A and sample B 29 Si{ 29 SiJ-mediated SQ-DQ NMR correlation spectra. In these spectra, the correlated signal intensity indicates covalent bonding. 29 Si atoms, including those transmitted via29 Si-O- 29 Those covalently bonded bridging oxygen atoms in the Si moiety. Signals along the diagonal correspond to those in the same local environment. 29 Si-O- 29 In the Si part, the correlated signal pairs that are equidistant on opposite sides of the diagonal and have the same two quantum shifts (vertical dimension) correspond to two different localities. 29 Si environment 29 Si-O- 29 The Si portion. For example, at -112 ppm in the single quantum (horizontal) dimension and -224 ppm in the double quantum (vertical) dimension in each spectrum. 29 The Si signal corresponds to the covalently bonded Q4(0Al) portion within the siliceous regions of each material. By comparison, the correlated signals at -216 ppm in the SQ (vertical) dimension and -105 ppm and -111 ppm in the DQ (horizontal) dimension of the spectrum obtained from sample A correspond to the covalently bonded Q4(0Al) and Q4(1Al) portions. Notably, a correlated signal near the diagonal at -209 ppm in the vertical dimension appears in the spectrum obtained from sample A but is not detected in the spectrum obtained from sample B. These signals correspond to the covalently bonded Q4(1Al) portion existing in the framework Al with an Al-O-(Si-O)2-Al configuration.

[0204] Example 4: Measurement of covalent bond connectivity via solid-state / heteronuclear multi-quantum coherence (HQMC) NMR

[0205] Similarly, solid-state 2D NMR technology can also be used to detect J-coupled heteroatoms (such as...) in aluminosilicate materials. 27 Al and 29 The covalent bond connectivity between Si). In some implementations, 2D 27 Al{ 29 SiJ-mediated heteronuclear multiquantum coherence (HMQC) NMR spectroscopy can produce information about the framework in aluminosilicate zeolites. 27 Direct information about Al atoms and can be distinguished 27 Al-O- 29 Different types and distributions of Si fractions.

[0206] In one implementation scheme Figure 4A and Figure 4B Showing for H + - 2D samples of form A and B were obtained 27 Al{ 29 SiJ-HMQC NMR spectra. Spectra were obtained at 9.4 T, 8 kHz MAS, and 100 K. These spectra reveal a concentration at 57 ppm. 27The A1 signal corresponds to the frame. 29 The Si atom-related four-coordinate framework Al atoms. In the spectra obtained from both samples, this... 27 The Al signal corresponds to -106 ppm at the Q4(1Al) portion. 29 The Si signal is correlated. The spectrum of sample A is shown at 57 ppm from framework Al atoms. 27 Al signal and its allocation to Q 4 (2Al) matter in 29 Additional correlated signal intensity was observed between the signals at -99 ppm in the Si dimension. This signal was not observed in the spectrum obtained from sample B, indicating that these portions are not present to a significant degree. This provides further evidence that sample A contains more locally paired Al atoms separated by one or two O-Si-O portions than sample B. The different distribution of framework Al atoms in samples A and B (including the type and number of adjacent framework Al atoms) is thought to explain their different adsorption and reaction properties.

[0207] Example 5

[0208] To further illustrate the spectral characteristics of the third nearest neighbor (3NN) paired Al, the 2D spectra of the third sample (referred to as sample C) were analyzed. 29 Si{ 29 Si}J-mediated solid-state single-quantum-two-quantum NMR correlation spectra show that Figure 8 In the middle, J coupling occurs between NMR active nuclei of covalently bonded atoms or through other covalently bonded atoms. Sample C has a SAR of 11, compared to approximately 19 for samples A and B; the synthesis of sample C is similar to that of sample A. Figure 8 2D in 29 Si{ 29 Si}J mediated SQ- DQ NMR correlation spectra are based on their isotropic nature. 29 Si chemical shift analysis from 29 The signals of the J-coupled pairs of Si nuclei were obtained under the same conditions as samples A and B. The correlation signals at -112 ppm in the single quantum (SQ) dimension and -224 ppm in the double quantum (DQ) dimension correspond to the Q-coupled pairs covalently bonded by bridging oxygen atoms. 4 (0Al) substance pairs (e.g., 29 Si-O- 29 Si), while the signals at -216 ppm in the two quantum dimensions and at -105 ppm and -111 ppm in the single quantum dimensions correspond to Q similarly through covalent bonding of bridging oxygen atoms. 4 (1Al) and Q4 (0Al) substance. Most importantly, the correlation (SQ, DQ) intensities at (-104 ppm, -208 ppm) correspond to paired Q. 4 (1Al) material, which provides direct evidence for the third nearest neighbor aluminum configuration.

[0209] Example 6

[0210] In addition to probing covalent bonding through J-coupling, solid-state NMR can also utilize spatial... 29 Si- 29 Si dipole-dipole coupling is used to probe nuclei with proximity at greater distances (approximately 1 nm), and this dipole-dipole coupling is based on their isotropic properties. 29 Si chemical shift analysis from 29 The signal of the dipole coupling pair of the Si core. Figures 9(A) and 9(B) show the 2D signals of two samples (sample C and sample D) with SAR 11, respectively. 29 Si{ 29 The Si} dipole-mediated NMR correlation spectrum revealed distinct intensity distributions, indicating different Al distributions within the zeolite framework. The synthesis of sample D was similar to that of sample B. These measurements are consistent with the aforementioned 2D... 29 Si{ 29 The correlation was performed under the same conditions as the Si}J-mediated correlation spectrum. The regions of correlation signal intensity correspond to a separation of approximately 1 nm. 29 Close pairs of Si nuclei (and their associated atoms). Signals at -112 ppm in the single quantum dimension and approximately -223 ppm in the two quantum dimensions correspond to close Q values. 4 (0Al) matter. Signals at -105 ppm and approximately -111 ppm in a single quantum dimension correlate with a signal at -216 ppm in a two-quantum dimension, and correspond to approximately Q... 4 (0Al) and Q 4 (1Al) matter. Signals centered at -105 ppm in a single quantum dimension and signals centered at -210 ppm in a two-quantum dimension correspond to approximately Q... 4 (1Al) Substance pair. Although both samples C and D exhibit characteristics from close Q... 4 (1Al) 2D of the frame part 29 Si{ 29 The intensity of Si is the same, but interestingly, their intensity distributions are different. For example, along the double diagonal of the two spectra, the 2D intensity of sample C is different from that of sample D. 29 Si{ 29The Si} intensity distribution is narrower and more elongated, and sample D appears more heterogeneous and wider. This indicates that the framework Al environment in sample C is locally more homogeneous than the framework Al environment in sample D.

[0211] Example 7

[0212] To understand the differences in the spectral characteristics of third nearest neighbor (3NN) type paired Al substances in zeolite materials prepared by different methods, the 2D spectra of sample D were analyzed. 29 Si{ 29 Si}J-mediated SQ-DQ solid-state NMR correlation spectra are shown in Figure 10 In the middle, sample D has a silicon-to-aluminum ratio (SAR) of 11, the same as sample C. Figure 10 The spectral analysis shown is derived from J-coupled 29 The signal from the Si nuclei is generated by the covalent bonding of the bridging oxygen atoms. 29 Si atom pairs ( 29 Si-O- 29 The spectrum shows the signal of Si. This spectrum was obtained under the same conditions as samples A, B, C, D, and G. The correlated single quantum number (SQ) at -112 ppm is also shown. 29 Si signal and dual quantum (DQ) at -224 ppm 29 The Si signal corresponds to the Q signal in localized silicon regions covalently bonded by bridging oxygen atoms. 4 (0Al) 29 Si material pairs ( 29 Si-O- 29 Si). At -111ppm and -105ppm on the SQ dimension. 29 DQ at -216, related to the Si signal. 29 The Si signal corresponds to the J-coupled Q signal. 4 (0Al) and Q 4 (1Al) 29 The Si portion through bond pairs. With SQ at -104 ppm. 29 DQ at -210 ppm, correlated with Si signal 29 The Si signal corresponds to J-coupling. 29 Q of the Si core 4 (1Al)-OQ 4 (1Al) pairs provide 3NN pairs of Al atoms in the zeolite framework (i.e., - 27 Al-O- 29 Si-O- 29 Si-O- 27Evidence for the Al-m portion. Notably, the signal intensity appears to be weaker than the same signal in sample C of Example 5, indicating that sample D contains fewer third nearest neighbor tetrahedral sites (T sites) than sample C.

[0213] Example 8

[0214] For further comparison, a third low-SAR chalcogenide material, namely sample G, was prepared and analyzed. Sample G has an SAR of approximately 11, similar to samples C and D. Figure 11 Displaying the 2D of sample G 29 Si{ 29 SiJ-mediated SQ-DQ solid-state NMR correlation spectra. These spectra were obtained under the same conditions as those of samples A, B, C, D, and G, which exhibited similar spectra. 2D 29 Si{ 29 SiJ-mediated SQ-DQ solid-state NMR correlation spectroscopy reveals J-coupling. 29 The correlation signal generated by the Si check corresponds to 29 Si-O- 29 Si covalent bond linking. Figure 11 The single quantum number (SQ) at -112 ppm is shown. 29 Si signal and dual quantum (DQ) at -224 ppm 29 The correlation strength between Si signals corresponds to the covalently connected Q signals. 4 (0Al) substance pair. As for the other samples, with SQ at -105ppm and -111ppm... 29 DQ at -216 ppm, correlated with Si signal 29 The Si signal corresponds to Q. 4 (0Al)-OQ 4 (1Al) link. Most notably, the DQ at -210 ppm... 29 Si signal and SQ at -105ppm 29 The Si signal is correlated, which corresponds to the covalently connected Q with the third nearest neighbor paired aluminum configuration. 4 (1Al)-OQ 4 (1Al) Framework section pair. It is worth noting that this related... 29 Si{ 29 The Si signal is much stronger than that observed in this spectral region of samples A, B, C, and D (see above), indicating that the number of 3NN paired-Al configurations in sample G is greater than that in these other samples. Furthermore, Figure 11The larger width of the correlation intensity near (-210ppm, -105ppm) indicates a wider distribution of different 3NN paired Al configurations in sample G compared to other samples.

Claims

1. A zeolite catalyst having paired aluminum atoms, wherein the zeolite catalyst is prepared by using H-FAU as both an Al source and a Si source, wherein the paired aluminum atoms are the third nearest neighbors (3NN) in the zeolite structure, and wherein the zeolite catalyst has aging durability, improved catalytic activity, or a combination thereof. The zeolite catalyst is a CHA zeolite catalyst, and When using 2D 29 Si{ 29 Si} J During SQ-DQ NMR measurements mediated by the catalyst, the zeolite catalyst exhibited properties in the single-quantum (SQ) dimension ranging from -104 ppm to -108 ppm and in the double-quantum (DQ) dimension ranging from -208 ppm to -212 ppm. 29 Si NMR characteristics.

2. The zeolite catalyst according to claim 1, wherein the CHA zeolite catalyst is a copper-CHA catalyst.

3. The zeolite catalyst according to claim 1 or 2, wherein when using 2D 27 Al{ 29 Si} J- During HMQC NMR measurements, the zeolite catalyst exhibits [the following characteristics]: 29 Si dimension in the range of -98ppm to -100ppm and in 27 NMR characteristics in the Al dimension in the range of 55 ppm to 60 ppm.

4. The zeolite catalyst according to claim 1, wherein the aging durability is defined as, after hydrothermal aging at 800°C, the zeolite catalyst exhibits 10% higher NO content compared to zeolite without the 3NN sites. x Conversion rate.

5. The zeolite catalyst according to claim 1, wherein the aging durability is defined as the zeolite catalyst exhibiting at least 50% NO after hydrothermal aging at 850°C. x Conversion rate.

6. The zeolite catalyst according to claim 1, wherein the improved catalytic activity of the zeolite catalyst for methanol dimerization has a 10% higher conversion rate relative to zeolites without the 3NN site.

7. The zeolite catalyst according to claim 1, wherein the zeolite catalyst has a SiO2 / Al2O3 ratio (SAR) of 8-40.

8. The zeolite catalyst according to claim 1, wherein the zeolite catalyst has a SiO2 / Al2O3 ratio (SAR) of 10-30.

9. The zeolite catalyst according to claim 1, wherein the zeolite catalyst has a SiO2 / Al2O3 ratio (SAR) of 11-25.

10. The zeolite catalyst according to claim 1, wherein the zeolite catalyst further comprises copper (Cu), wherein the Cu content corresponds to a Cu / Al ratio of 0.2 to 0.

5.

11. The zeolite catalyst according to claim 10, wherein the Cu content corresponds to a Cu / Al ratio of 0.25 to 0.

45.

12. The zeolite catalyst according to claim 10, wherein the Cu content corresponds to a Cu / Al ratio of 0.3 to 0.

4.

13. An effective method for reducing nitrogen oxides (NOx) from lean-burn engine exhaust. x The catalyst article comprises a substrate support having a selective catalytic reduction (SCR) catalyst, the selective catalytic reduction (SCR) catalyst comprising a zeolite catalyst according to any one of claims 1 to 12.

14. The catalyst article of claim 13, wherein the substrate support is a honeycomb substrate and optionally made of metal or ceramic.

15. The catalyst article according to claim 14, wherein the honeycomb substrate carrier is a flow-through substrate or a wall-flow filter.

16. A waste gas treatment system, the waste gas treatment system comprising: A lean-burn engine that produces exhaust gas flow; and The catalyst article according to any one of claims 13 to 15, wherein the catalyst article is located downstream of the lean-burn engine and in fluid communication with the exhaust gas flow.

17. The waste gas treatment system according to claim 16, further comprising one or more of the following: a. A diesel engine oxidation catalyst (DOC), wherein the diesel engine oxidation catalyst is located upstream of the catalyst product; b. A smoke filter located upstream of the catalyst product; and c. Ammonia oxidation catalyst (AMOX), wherein the ammonia oxidation catalyst is located downstream of the catalyst product.

18. A method for preparing a selective catalytic reduction (SCR) catalyst, the method comprising: (a) Preparation of a zeolite catalyst according to any one of claims 1 to 12; (b) Apply the catalyst as a coating onto a ceramic or metal honeycomb substrate; (d) Dry the coated material; (e) Calcine the coated monolith at a temperature in the range of 400°C to 800°C.

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