Synthesis of CHA zeolite material, CHA zeolite material obtainable therefrom, and SCR catalyst containing same

Abstract

A process for preparing a zeolite having a CHA-type framework structure comprising X2O3 and YO2, where X is a trivalent element and Y is a tetravalent element, comprising: (1) providing (A) a source of X2O3; (B) a source of YO2; and (C) a zeolite of formula (I), where R 1a is C1-C8 alkyl and C3-C 10 cycloalkyl; R 1b C2-C8 alkyl and C3-C 10 cycloalkyl, where R2, R3, R4, R5, and R6 are, independently of each other, H, hydroxyl, or C1-C8 alkyl; and (2) subjecting the synthesis mixture to crystallization conditions to form a CHA zeolite. [Case 1] TIFF2024534758000018.tif37128

Description

[Technical field]

[0001] The present invention relates to a process for the synthesis of a zeolitic material having a CHA framework structure, to the zeolitic material obtainable therefrom, and to an SCR catalyst comprising the same. [Background technology]

[0002] Catalytic articles are essential for modern internal combustion engines to treat exhaust gases therefrom before they are released into the air. Exhaust gases from internal combustion engines typically contain particulate matter (PM), nitrogen oxides (NOx), such as NO and / or NO2, unburned hydrocarbons (HC), and carbon monoxide (CO). Control of NOx emissions has always been one of the most important topics in the automotive sector, due to the adverse environmental effects of NOx on ecosystems, animal and plant life.

[0003] One of the effective technologies for removing NOx from the exhaust of internal combustion engines is selective catalytic reduction (SCR) of NOx with ammonia or a second ammonia source. Recently, small pore zeolites have been proposed for the selective catalytic reduction of NOx, among which CHA-type zeolites have been extensively studied and found to be one of the most promising SCR catalysts, especially when the zeolites are exchanged with metal promoters such as Cu or Fe.

[0004] Chabazite is a type of naturally occurring zeolite, and also has a synthetic CHA form. A well-known synthetic CHA-type zeolite is a crystalline CHA material called SSZ-13, as reported in U.S. Pat. No. 4,544,538. SSZ-13 was prepared under crystallization conditions using a structure directing agent comprising an N-alkyl-3-quinuclidinol cation, an N,N,N-trialkyl-1-adamantammonium cation, an N,N,N-trialkyl-2-exoaminonorbornane cation, or a mixture thereof. The synthesis of CHA-type zeolites using other structure directing agents has also been developed, as reported, for example, in the following non-patent and patent publications:

[0005] Itakura Masaya et.al. in Chemistry Letters, 2008, Vol. 37, No. 9, pages 908 to 909, describe a process for synthesizing CHA zeolite using benzyltrimethylammonium hydroxide as a structure directing agent.

[0006] US Patent Application Publication No. 2010 / 254895(A1) discloses a process for preparing CHA-type zeolites using a cationic 1,4-diazabicyclo[2.2.2]octane structure directing agent together with at least one cationic cyclic nitrogen-containing structure directing agent.

[0007] WO 2020 / 039074(A1) describes a compound of the formula [NR 1 R 2 R 3 R 4 ](wherein, R 1 , R 2 , R 3 and R4 is independently a C1-C4-alkyl group optionally substituted with one or more hydroxy groups.

[0008] Biaohua Chen et al. in Environmental Science & Technology, 2014, 48, pages 13909 to 13916 describe a process for synthesizing SSZ-13 using choline chloride as a structure directing agent.

[0009] WO 2013 / 035054 A1 relates to a process for preparing zeolitic materials having a CHA-type framework structure, which uses an N,N-dimethylammonium organic template, including N,N-dimethylpiperidinium.

[0010] There remains a need for further processes for preparing zeolitic materials having a CHA framework structure, in particular processes that can provide CHA-type zeolitic materials with improved catalytic performance for the selective catalytic reduction of NOx. Summary of the Invention

[0011] The object of the present invention is to provide a novel process for preparing a zeolite material having a CHA framework structure. Another object of the present invention is to provide an SCR catalyst based on a zeolite having a CHA framework structure, which has improved catalytic performance for selective catalytic reduction of NOx.

[0012] This objective has been achieved by using piperidinium-based organic structure directing agents in zeolite synthesis. Surprisingly, it has been found that zeolites having a CHA framework structure prepared using piperidinium-based organic structure directing agents have desirable activity combined with excellent stability, especially against aging at high temperatures, e.g., above 800°C.

[0013] Thus, in a first aspect, the present invention provides a process for preparing a zeolitic material having a CHA-type framework structure, the framework structure comprising X2O3 and YO2, where X is a trivalent element and Y is a tetravalent element, (1) (A) A source of X2O3; (B) A source of YO2, and (C) a source of piperidinium cation represented by formula (I) as an organic structure directing agent (OSDA),

[0014] [ka] During the ceremony, R 1a is C1-C8 alkyl and C3-C 10 cycloalkyl; R 1b is C2-C8 alkyl and C3-C 10 cycloalkyl; preparing a synthesis mixture comprising a source, wherein R2, R3, R4, R5, and R6 are each independently H, hydroxyl, or C1-C8 alkyl; (2) subjecting the synthesis mixture to crystallization conditions to form a CHA zeolite.

[0015] In a second aspect, the present invention relates to a zeolite having a CHA-type framework structure obtained and / or obtainable by the process described herein.

[0016] In a third aspect, the present invention relates to a zeolite having a CHA-type framework structure obtained and / or obtainable by the process described herein, the zeolite comprising a promoter metal M.

[0017] In a fourth aspect, the present invention relates to the use of a zeolite having a CHA-type framework structure according to the second or third aspect in a catalyst for selective catalytic reduction (SCR) of NOx.

[0018] In a fifth aspect, the present invention relates to a catalyst article, in the form of an extrudate comprising an SCR catalyst composition or in the form of a monolith comprising a washcoat containing an SCR catalyst composition on a substrate, the SCR catalyst composition comprising a zeolite having a CHA-type framework structure comprising a promoter metal as described herein.

[0019] In a sixth aspect, the present invention relates to an exhaust gas treatment system comprising an internal combustion engine and an exhaust gas conduit in fluid communication with the internal combustion engine, wherein a catalytic article as described herein is present in the exhaust gas conduit. [Brief description of the drawings]

[0020] [Figure 1] 4 shows SEM images of the zeolites from Examples 1 to 6, respectively. [Diagram 2] 4 shows the XRD patterns of the zeolites from Examples 1 to 7, respectively. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] The present invention is described in detail below. It should be understood that the present invention can be embodied in many different ways and should not be construed as limited to the embodiments set forth herein.

[0022] As used herein, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. The terms "comprise," "comprising," and the like are used interchangeably with "contain," "containing," and the like, and are to be interpreted openly and without restriction; that is, for example, additional components or elements may be present. The phrases "consists of" or "consists essentially of" or cognate words may be included in "comprises" or cognate words.

[0023] As used herein, the terms "zeolite having a CHA-type framework structure", "CHA-type zeolite", "CHA zeolite", and the like are intended to refer to molecular sieve materials exhibiting an XRD pattern of a CHA-type framework structure, and are hereinafter used interchangeably. These terms are also intended to include any form of zeolite, such as as-synthesized, calcined, NH4-exchanged, H-form, and metal-substituted forms.

[0024] As used herein, the term "as-synthesized" is intended to refer to the zeolite in its form after crystallization and drying, prior to removal of the organic structure directing agent.

[0025] As used herein, the term "calcined form" is intended to refer to the zeolite in its form upon calcination.

[0026] In a first aspect, the present invention provides a process for preparing a zeolite having a CHA-type framework structure, the framework structure comprising X2O3 and YO2, where X is a trivalent element and Y is a tetravalent element; (1) (A) A source of X2O3; (B) A source of YO2, and (C) a source of piperidinium cation represented by formula (I) as an organic structure directing agent (OSDA),

[0027] [ka] During the ceremony, R 1a is C1-C8 alkyl and C3-C 10 cycloalkyl; R 1b is C2-C8 alkyl and C3-C 10 cycloalkyl; preparing a synthesis mixture comprising a source, wherein R2, R3, R4, R5, and R6 are each independently H, hydroxyl, or C1-C8 alkyl; (2) subjecting the synthesis mixture to crystallization conditions to form a CHA zeolite.

[0028] The synthesis mixture provided in step (1) comprises a source of X2O3, where X is a trivalent framework element, and a source of YO2, where Y is a tetravalent framework element. X may be any trivalent element. Preferably, X is selected from the group consisting of Al, B, In, Ga, and any combination thereof, with Al being more preferred. Y may also be any tetravalent element. Preferably, Y is selected from the group consisting of Si, Sn, Ti, Zr, Ge, and any combination thereof, with Si being more preferred. In particular, X is Al and Y is Si.

[0029] Suitable sources of X2O3 may be any known material useful for providing trivalent framework elements during zeolite synthesis. In some embodiments where X is Al, suitable examples of sources of Al2O3 may include, but are not limited to, alumina, aluminum hydroxide, aluminate, aluminum alkoxide, aluminum salt, FAU zeolite, LTA zeolite, LTL zeolite, BEA zeolite, MFI zeolite, and any combination thereof, more preferably alumina, aluminum alkoxide, aluminum salt, FAU zeolite, and any combination thereof. In particular, sources of Al2O3 may be selected from alumina, AlO(OH), Al(OH)3, aluminum tri(C1-C5)alkoxide, aluminum halide, aluminum sulfate, aluminum phosphate, aluminum fluorosilicate, FAU zeolite, and any combination thereof. For example, the FAU zeolite may be selected from the group consisting of faujasite, [Al-Ge-O]-FAU, [Al-Ge-O]-FAU, [Ga-Al-Si-O]-FAU, [Ga-Ge-O]-FAU, [Ga-Si-O]-FAU, CSZ-1, Na-X, US-Y, ECR-30, LZ-210, Li-LSX, SAPO-37, Na-Y, ZSM-20, ZSM-3, zeolite X, and zeolite Y, more preferably from the group consisting of faujasite, Na-X, zeolite X, zeolite Y, US-Y, and LZ-210. Zeolite Y may be specifically mentioned as a source of X2O3.

[0030] Suitable sources of YO2 may be any known material useful for providing tetravalent framework elements during zeolite synthesis. In some embodiments where Y is Si, suitable sources of YO2 may include, but are not limited to, fumed silica, precipitated silica, silica hydrosol, silica gel, colloidal silica, silicic acid, silicon alkoxide, alkali metal silicate, sodium metasilicate hydrate, sesquisilicate, disilicate, silicic acid ester, FAU zeolite, LTA zeolite, LTL zeolite, BEA zeolite, MFI zeolite, and any combination thereof. In particular, the source of YO2 may be selected from fumed silica, sodium silicate, potassium silicate, FAU zeolite, and any combination thereof, more preferably fumed silica, FAU zeolite, and any combination thereof. For example, the FAU zeolite may be selected from the group consisting of faujasite, [Al-Ge-O]-FAU, [Al-Ge-O]-FAU, [Ga-Al-Si-O]-FAU, [Ga-Ge-O]-FAU, [Ga-Si-O]-FAU, CSZ-1, Na-X, US-Y, ECR-30, LZ-210, Li-LSX, SAPO-37, Na-Y, ZSM-20, ZSM-3, zeolite X, and zeolite Y, more preferably from the group consisting of faujasite, Na-X, zeolite X, zeolite Y, US-Y, and LZ-210. In particular, one or more materials selected from the group consisting of fumed silica, precipitated silica, silica hydrosol, silica gel, colloidal silica, and zeolite Y may be mentioned as a source of YO2.

[0031] It is understood that the sources of X2O3 and YO2 can be provided separately (i.e., separate sources) and / or together (i.e., combined sources). In the latter case, the sources may be provided, for example, by zeolites containing framework elements X and Y. It may be contemplated that the synthesis mixture provided in step (1) may include one or both of a combined source of X2O3 and YO2 and separate sources of X2O3 and YO2.

[0032] In some particular embodiments, the synthesis mixture provided in step (1) comprises a source of Al2O3 and a source of SiO2. Thus, the process according to the invention results in an aluminosilicate zeolite having a CHA framework structure.

[0033] The term "aluminosilicate", when used within the context of zeolites, is intended to mean a framework composed primarily of alumina and silica, which may or may not include framework elements other than oxygen, aluminum, and silicon.

[0034] In certain exemplary embodiments, the synthesis mixture provided in step (1) comprises an FAU zeolite as a combined source of Al2O3 and SiO2, and an additional source of SiO2. In particular, the FAU zeolite is zeolite Y, preferably having a molar ratio of SiO2 to Al2O3 of 40 or less, 30 or less, 20 or less, or even 10 or less. The additional source of SiO2 is selected from the group consisting of fumed silica, precipitated silica, silica hydrosol, silica gel, and colloidal silica (including mixtures of two or more thereof).

[0035] The synthesis mixture provided in step (1) has a YO2:X2O3 molar ratio of the source of YO2, calculated as YO2, to the source of X2O3, calculated as X2O3, in the range of 5 to 100, for example, 15 to 80, 35 to 60, or 40 to 60.

[0036] In some embodiments, the organic structure directing agent is a compound containing a piperidinium cation represented by formula (I):

[0037] [ka] During the ceremony, R 1a is C1-C8 alkyl and C3-C 10 cycloalkyl; R 1bis C3-C8 alkyl and C3-C 10 cycloalkyl; R2, R3, R4, R5, and R6 are each independently H, hydroxyl, or C1-C8 alky.

[0038] In some further embodiments, the organic structure directing agent is a compound containing a piperidinium cation represented by formula (Ia):

[0039] [ka] During the ceremony, R 1a is C1-C5 alkyl and C5-C 10 cycloalkyl; R 1b is C3-C5 alkyl and C5-C 10 cycloalkyl; R3, R4, and R5 are each independently H, hydroxyl, or C1-C5 alkyl.

[0040] Specifically, the organic structure directing agent is R 1a is C1-C5 alkyl, R 1b is a C3-C5 alkyl; and R3, R4, and R5 are each independently H, hydroxyl, or C1-C5 alkyl.

[0041] More specifically, the organic structure directing agent is R 1a is C1-C3 alkyl, R 1b is a C3-C5 alkyl, R3 and R5 are each independently H or a C1-C5 alkyl, and R4 is H.

[0042] In certain exemplary embodiments, the organic structure directing agent is R 1a is C1-C3 alkyl, R1b is a C3-C5 alkyl; and R3, R4, and R5 are H.

[0043] For example, the organic structure directing agent may be selected from compounds containing 1-methyl-1-ethylpiperidinium, 1-methyl-1-n-propylpiperidinium, 1-methyl-1-n-butylpiperidinium, 1,1-diethylpiperidinium, 1-ethyl-1-n-propylpiperidinium, or 1-ethyl-1-n-butylpiperidinium, or any combination of compounds, among which particular mention may be made of compounds containing 1-methyl-1-n-propylpiperidinium, 1-methyl-1-n-butylpiperidinium, or 1-ethyl-1-n-propylpiperidinium, and any combination thereof.

[0044] In some particular embodiments, the synthesis mixture provided in step (1) does not include any organic structure directing agent cations other than piperidinium cations.

[0045] Preferably, the organic structure directing agent can be in the form of a salt of piperidinium cation.The counter ion contained in the organic structure directing agent is not particularly limited, and can be selected from the group consisting of halides such as fluoride, chloride and bromide; hydroxide, sulfuric acid, nitric acid; and carboxylic acid such as acetic acid, and preferably selected from the group consisting of chloride, bromide, hydroxide and sulfate.

[0046] Preferably, the organic structure directing agent is the hydroxide, chloride or bromide, in particular the hydroxide of the piperidinium cation of formula (I) and (Ia) as hereinbefore described.

[0047] The organic structure directing agent may be present in the synthesis mixture provided in step (1) in a piperidinium:YO2 molar ratio relative to the source of YO2, calculated as YO2, ranging from 0.01 to 1.0, such as 0.03 to 0.5, 0.03 to 0.2, or 0.05 to 0.15.

[0048] The synthesis mixture provided in step (1) may further comprise a source of alkali metal and / or alkaline earth metal cations (AM), preferably an alkali metal cation. The alkali metal is preferably selected from the group consisting of Li, Na, K, Cs, and any combination thereof, more preferably Na and / or K, and most preferably Na. The alkaline earth metal is preferably selected from the group consisting of Mg, Ca, Sr, and Ba, and any combination thereof. Suitable sources of alkali metal and / or alkaline earth metal cations (AM) are typically halides, such as fluorides, chlorides, and bromides, of alkali metal and / or alkaline earth metal; hydroxides, sulfates, nitrates; and carboxylates, such as acetates, or any combination thereof. Preferably, the source of alkali metal and / or alkaline earth metal cations (AM) includes chlorides, bromides, hydroxides, or sulfates of alkali metal and / or alkaline earth metal, or any combination thereof. More preferably, an alkali metal hydroxide is used in the synthesis mixture.

[0049] The alkali metal and / or alkaline earth metal cation (AM) may be present in the synthesis mixture in a molar ratio relative to the source of YO2, calculated as AM to YO2, ranging from 0.01 to 1.0, such as 0.1 to 1.0, 0.3 to 0.8, or 0.5 to 0.7.

[0050] The synthesis mixture provided in step (1) contains an anion OH - A useful source of OH - The source of the anion OH may be, for example, a metal hydroxide, such as an alkali metal hydroxide or ammonium hydroxide. - may be derived from one or more of a source of alkali metal and / or alkaline earth metal cations (AM) and an organic structure directing agent.

[0051] OH - The anion in the synthesis mixture is OH -The molar ratio to the YO2 source, calculated relative to YO2, may be in the range of 0.1 to 2.0, for example, 0.2 to 1.0, or 0.5 to 1.0.

[0052] The synthesis mixture provided in step (1) may also contain at least one solvent, preferably water, more preferably deionized water. The solvent may be included in, and thereby carried into, one or more of the starting materials of the synthesis mixture, such as X2O3, YO2, and the source of the organic structure directing agent, and / or may be separately incorporated into the synthesis mixture.

[0053] In some embodiments, the synthesis mixture has a molar ratio of the source of water to YO2, calculated as H2O to YO2, in the range of 3 to 100, such as 10 to 80, 20 to 70, or 30 to 60.

[0054] In some exemplary embodiments, the synthesis mixture provided in step (1) has the molar composition shown in Table 1 below.

[0055] [Table 1] 1) The amounts of X2O3 and YO2 sources are calculated as the respective oxides.

[0056] In some embodiments, the synthesis mixture provided in step (1) may further include an amount of CHA zeolite seed crystals. The CHA zeolite seed crystals can be obtained from the processes described herein without the use of seed crystals or from any other known process.

[0057] In step (2), the synthesis mixture may be subjected to crystallization conditions to form CHA zeolite, and is not particularly limited. Crystallization may be carried out at elevated temperatures in the range of 80 to 250°C, more preferably 100 to 200°C, for a period of time sufficient for crystallization, such as 0.5 to 12 days or 1 to 6 days. Typically, crystallization is carried out under autogenous pressure, for example in a pressure vessel such as an autoclave. Furthermore, crystallization may be carried out with or without stirring.

[0058] The CHA zeolite formed by crystallization may be subjected to a post-treatment procedure, including, for example, isolation by filtration, optionally washing, and drying, to obtain the as-synthesized CHA zeolite. Thus, step (2) in the process according to the invention optionally further comprises a post-treatment procedure.

[0059] As-synthesized CHA zeolites typically contain the above-mentioned piperidinium cations within their structural pores and / or channels.

[0060] In some embodiments, the as-synthesized CHA zeolite from step (2) may be subjected to a calcination procedure. Thus, the process according to the present invention further comprises a step (3) of calcining the as-synthesized CHA zeolite.

[0061] In some embodiments, the as-synthesized or calcined CHA zeolite has a structure in which one or more of the ionic non-framework elements contained in the zeolite is H. + and / or NH4 + The process according to the invention may thus be subjected to an ion exchange procedure, so that the (4) One or more of the ionic non-framework elements contained in the zeolite obtained in step (2) or (3) is oxidized with H + and / or NH4 + , preferably NH4 + The present invention further includes exchanging the

[0062] Generally, in step (4), H + and / or NH4+ The exchanged zeolite may be subjected to a work-up procedure, including, for example, isolation by filtration, optionally washing and drying, and / or may be subjected to a calcination procedure. Thus, step (4) in the process according to the invention optionally further comprises a work-up procedure and / or a calcination procedure.

[0063] The calcination in step (3) and / or step (4) may be carried out at a temperature in the range of 300 to 900° C., for example 350 to 700° C. or 400 to 650° C. In particular, the calcination may be carried out under a gas atmosphere having a temperature in the above range, which may be air, oxygen, nitrogen, or a mixture of two or more thereof. Preferably, the calcination is carried out for a period in the range of 0.5 to 10 hours, for example 3 to 7 hours or 4 to 6 hours.

[0064] It was possible to successfully obtain a zeolite having a CHA framework structure from the process described in the first embodiment, as determined by X-ray powder diffraction (XRD) analysis.

[0065] Thus, in a second aspect, the present invention also provides a zeolite having a CHA-type framework structure obtainable and / or obtainable from the process according to the first aspect.

[0066] Zeolites having a CHA-type framework have a YO2:X2O3 molar ratio (SAR) of YO2 (e.g., silica) to X2O3 (e.g., alumina) of 2 or more, the molar ratio being preferably in the range of 4 to 200, more preferably 6 to 100, more preferably 8 to 50, more preferably 10 to 35, more preferably 11 to 25, more preferably 11.5 to 20, more preferably 12 to 16, more preferably 12.5 to 15, more preferably 13 to 14. According to the present invention, the YO2:X2O3 molar ratio refers to a zeolite having a CHA-type framework, preferably in its calcined form, more preferably in its calcined H form.

[0067] Zeolites having a CHA framework structure according to the present invention typically have an average crystal size of up to 2 μm, or up to 1.5 μm, for example in the range of 200 nm to 1.5 μm. The average crystal size can be determined by scanning electron microscopy (SEM). In particular, the average crystal size was determined via SEM by measuring the crystal size for at least 30 different crystals randomly selected from multiple images covering different regions of the sample.

[0068] In some embodiments, the zeolite having a CHA-type framework structure according to the present invention has a molecular weight of 60 2 / g or less, preferably 50m 2 / g or less, more preferably 45m 2 / g or less, for example, 1 to 50 m 2 / g or 3~40m 2 Alternatively or in addition, the zeolite having a CHA-type framework structure may have a mesopore surface area (MSA) of at least 400 m 2 / g, or at least 450m 2 / g, e.g. 450~650m 2 / g or 450~600m 2 The zeolitic surface area (ZSA) ranges from 0.1 to 1.0 μm / g. The MSA and ZSA can be determined via N2 adsorption porosimetry.

[0069] The zeolite having a CHA-type framework structure according to the present invention is preferably at least 90% phase pure, i.e., at least 90% of the zeolite framework is CHA-type, as determined by X-ray powder diffraction (XRD) analysis. More preferably, the zeolite having a CHA-type framework structure is at least 95% phase pure, or even more preferably at least 98% or at least about 99% phase pure. Correspondingly, the zeolite having a CHA-type framework structure may contain some other frameworks as intergrowths in small amounts, for example less than 10%, preferably less than 5%, even more preferably less than 2% or less than 1%.

[0070] Surprisingly, it has been found that zeolites having a CHA-type framework structure obtained from the process according to the first aspect exhibit significantly higher stability towards ageing at temperatures of 800° C. or higher in selective catalytic reduction (SCR) of NOx applications compared to catalysts comprising zeolites having the same framework type but prepared by other methods.

[0071] Thus, in a third aspect, the present invention further provides a zeolite having a CHA-type framework structure obtained and / or obtainable by a process according to the invention, the zeolite comprising a promoter metal M.

[0072] As used herein, the term "promoter metal" preferably refers to a non-framework metal capable of improving the catalytic activity of a zeolite. "Non-framework metal" is intended to mean that the metal does not participate in the formation of the zeolite framework structure. The promoter metal may be present within the zeolite and / or at least a portion of the zeolite surface, preferably in the form of an ionic species.

[0073] In particular, the promoter metal is present in and / or on a zeolite having a CHA-type framework structure.

[0074] The zeolite having a CHA-type framework structure is obtained and / or obtainable by the process according to the first aspect and / or according to the second aspect. Any general and specific description relating to the process according to the first aspect or the zeolite having a CHA-type framework structure according to the second aspect is incorporated herein by reference.

[0075] The promoter metal may be any metal known to be useful for improving the catalytic performance of zeolites in selective catalytic reduction (SCR) applications of NOx. In general, the promoter metal may be selected from transition metals, such as precious metals, such as Au and Ag, and platinum group metals, base metals, such as Cr, Zr, Nb, Mo, Fe, Mn, W, V, Ti, Co, Ni, Cu, and Zn, alkaline earth metals, such as Ca and Mg, and Sb, Sn, and Bi, and any combination thereof.

[0076] In a preferred embodiment, the zeolite having a CHA-type framework structure contains at least Cu and / or Fe as a promoter metal. In some particular embodiments, the zeolite contains Cu as a promoter metal. In particular, the promoter metal in the zeolite consists of Cu.

[0077] The promoter metal may be present in the zeolite having a CHA-type framework structure in an amount of 0.1 to 10% by weight, preferably 0.5 to 10% by weight, on an oxide basis, based on the total weight of the promoter metal and the zeolite having a CHA-type framework structure. In some particular embodiments in which copper, iron, or a combination thereof is used as the promoter metal, the promoter metal is preferably present in the zeolite having a CHA-type framework structure in an amount of 1 to 8% by weight, more preferably 2 to 7% by weight, on an oxide basis, based on the total weight of the promoter metal and the zeolite having a CHA-type framework structure.

[0078] Alternatively, the promoter metal may be present in the zeolite having a CHA-type framework structure in an amount of 0.01 to 2 mol, preferably 0.03 to 1.8 mol, more preferably 0.05 to 1.5 mol, more preferably 0.08 to 1.2 mol, more preferably 0.1 to 1.0 mol, more preferably 0.13 to 0.8 mol, more preferably 0.15 to 0.5 mol, more preferably 0.18 to 0.4 mol, more preferably 0.2 to 0.38 mol, more preferably 0.23 to 35 mol, more preferably 0.25 to 32 mol, and more preferably 0.28 to 0.3 mol, per mol of a trivalent framework element (e.g., Al) of the zeolite having a CHA-type framework structure. In some specific embodiments in which copper, iron, or a combination thereof is used as the promoter metal, the amount of the promoter metal is from 0.1 to 1.0 moles, more preferably from 0.13 to 0.8 moles, more preferably from 0.15 to 0.5 moles, more preferably from 0.18 to 0.4 moles, more preferably from 0.2 to 0.38 moles, more preferably from 0.23 to 35 moles, more preferably from 0.25 to 32 moles, and more preferably from 0.28 to 0.3 moles per mole of a trivalent framework element (e.g., Al) of the zeolite having a CHA-type framework structure.

[0079] In some preferred embodiments, the zeolite having a CHA-type framework structure and containing a promoter metal M is - an aluminosilicate zeolite having a CHA-type framework structure, with a silica-to-alumina molar ratio (SAR) of 10 to 25, preferably 12 to 20; - a promoter metal present in and / or on the zeolite, which is Cu and / or Fe, in particular Cu; Including, The promoter metal is present in an amount of 0.2 to 0.7 moles, preferably 0.3 to 0.5 moles, per mole of framework aluminum of the zeolite.

[0080] In some more preferred embodiments, the zeolite having a CHA-type framework structure and comprising the promoter metal M according to the present invention is - an aluminosilicate zeolite having a CHA-type framework structure, with a silica-to-alumina molar ratio (SAR) of 12 to 20, more preferably 12 to 16; - a promoter metal Cu present in and / or on the zeolite; Including, The zeolite, wherein Cu is present in an amount of 0.3 to 0.5 moles per mole of zeolite framework aluminum.

[0081] In an exemplary embodiment, the zeolite according to the present invention having a CHA-type framework structure and comprising a promoter metal M is an aluminosilicate zeolite having a CHA-type framework structure and a silica-to-alumina molar ratio (SAR) of -12 to 16; - a promoter metal Cu present in and / or on the zeolite; Including, The zeolite, wherein Cu is present in an amount of 0.3 to 0.5 moles per mole of zeolite framework aluminum.

[0082] Preferably, the zeolite according to the invention having a CHA-type framework structure and containing a promoter metal M is subjected to a test gas flow consisting of 500 vppm NO, 500 vppm NH, 5% by volume H2O, 10% by volume O, and the balance N2, for 120,000 h. -1 The zeolite can exhibit a NOx conversion of at least 11% at 200° C. and at least 50% at 575° C., when determined by using a Cu-promoted zeolite having a molar ratio Cu / X (e.g., Al) of 0.36 when aged at 820° C. at a gas hourly space velocity (GHSV) of 100° C. to 100° C. Preferably, the zeolite according to the present invention having a CHA-type framework structure and comprising a promoter metal M exhibits a NOx conversion of at least 30% or at least 50% at 200° C. and at least 70% or at least 80% at 575° C., when determined by using a Cu-promoted zeolite having a molar ratio Cu / X (e.g., Al) of 0.36 when aged at 820° C.

[0083] The promoter metal can be incorporated into the zeolite having a CHA-type framework structure by any known process, such as ion exchange and impregnation. For example, the promoter metal can be incorporated into the zeolite having a CHA-type framework structure by mixing the zeolite in a solution of a soluble precursor of the promoter metal. The zeolite ion-exchanged with the promoter metal, typically in the form of a cation, can be conventionally washed, dried and calcined. Useful soluble precursors of the promoter metal can be, for example, a salt of the promoter metal, a complex of the promoter metal, and combinations thereof. Alternatively, the promoter metal can be incorporated into the zeolite having a CHA-type framework structure in situ during the preparation of a catalytic article, such as an extrudate or a coated monolith.

[0084] In a fourth aspect, the present invention provides the use of a zeolite having a CHA-type framework structure obtained and / or obtainable by the process described herein, preferably comprising a promoter metal M as described herein, in a catalyst for selective catalytic reduction (SCR) of NOx, i.e. in an SCR application.

[0085] For SCR applications, the zeolite having a CHA-type framework structure, preferably loaded with promoter metals as described above, may be applied in the form of extrudates or in the form of a washcoat on a monolithic substrate.

[0086] Thus, in a fifth aspect, the present invention provides a catalyst article in the form of an extrudate comprising an SCR catalyst composition or in the form of a monolith comprising a washcoat containing an SCR catalyst composition on a substrate, the SCR catalyst composition comprising a zeolite having a CHA-type framework structure, the zeolite comprising a promoter metal M according to the third aspect.

[0087] The term "extrudate" generally refers to a shaped body formed by extrusion. According to the present invention, the extrudate comprising a zeolite having a CHA-type framework structure and a promoter metal typically has a honeycomb structure.

[0088] The term "washcoat" has its ordinary meaning in the art: a thin, adherent coating of catalytic or other material applied to a substrate.

[0089] The term "substrate" generally refers to a monolithic material upon which a catalytic coating is disposed, such as monolithic honeycomb substrates, particularly flow-through monolithic substrates and wall-flow monolithic substrates.

[0090] The zeolite having a CHA-type framework structure and the promoter metal can be processed into an applicable form by any known process without any particular limitation.

[0091] In a further aspect, the present invention relates to an exhaust gas treatment system comprising an internal combustion engine and an exhaust gas conduit in fluid communication with the internal combustion engine, wherein a catalytic article as described herein is present in the exhaust gas conduit.

[0092] Additionally, the present invention provides a process for the selective catalytic reduction of nitrogen oxides, comprising the steps of: (A) providing a gas stream comprising nitrogen oxides (NOx); (B) contacting the gas stream with a zeolite comprising a promoter metal according to any of the certain preferred embodiments described herein, or with a catalyst article according to any of the certain preferred embodiments described herein.

[0093] Finally, the present invention relates to the use of a zeolite having a CHA-type framework structure according to certain preferred embodiments described in the present application in a catalyst for the selective catalytic reduction of nitrogen oxides.

[0094] Embodiment The present invention is further described by the following set of embodiments and combinations of embodiments resulting from the specified dependencies and back citations. In particular, in each instance where a range of embodiments is mentioned, it should be noted that in the context of a term such as "... described in any one of embodiments 1 to 4", it means that all embodiments in this range are explicitly disclosed to those skilled in the art, i.e., the expression of this term is understood by those skilled in the art to be equivalent to "... described in any one of embodiments 1, 2, 3, and 4". Furthermore, it should be clearly noted that the following set of embodiments represents a properly structured part of the description directed to the general and preferred aspects of the present invention, rather than a set of claims defining the scope of protection.

[0095] 1. A process for preparing a zeolite having a CHA-type framework structure, the framework structure comprising X2O3 and YO2, where X is a trivalent element and Y is a tetravalent element; (1) (A) A source of X2O3; (B) A source of YO2, and (C) a source of piperidinium cation represented by formula (I) as an organic structure directing agent (OSDA),

[0096] [ka] During the ceremony, R 1a is C1-C8 alkyl and C3-C 10 cycloalkyl; R 1b is C2-C8 alkyl and C3-C 10 cycloalkyl; preparing a synthesis mixture comprising a source, wherein R2, R3, R4, R5, and R6 are each independently H, hydroxyl, or C1-C8 alkyl; (2) subjecting the synthesis mixture to crystallization conditions to form a CHA zeolite. 2. The piperidinium cation is represented by the following formula (I): R 1a is C1-C8 alkyl and C3-C 10 cycloalkyl; R 1b is C3-C8 alkyl and C3-C 10 cycloalkyl; 2. The process of embodiment 1, wherein R2, R3, R4, R5, and R6 are each independently H, hydroxyl, or C1-C8 alkyl. 3. The piperidinium cation is represented by formula (Ia)

[0097] [ka] During the ceremony, R 1a is C1-C5 alkyl and C5-C 10 cycloalkyl; R 1b is C3-C5 alkyl and C5-C 10 cycloalkyl; The process of embodiment 1 or 2, wherein R3, R4, and R5 are each independently H, hydroxyl, or C1-C5 alkyl. 4. The piperidinium cation is R 1a is C1-C5 alkyl, R 1b is C3-C5 alkyl; and R3, R4, and R5, each independently, are H, hydroxyl, or C1-C5 alkyl. 5. The piperidinium cation is R 1a is C1-C3 alkyl, R 1b is C3-C5 alkyl; R3 and R5 are each independently H or C1-C5 alkyl; and R4 is H. 6. The piperidinium cation is R 1a is C1-C3 alkyl, R 1bThe process of any of embodiments 3-5, wherein the compound is represented by formula (Ia), wherein R is C-C alkyl; and R, R, and R are H. 7. The process according to any one of the preceding embodiments, wherein the piperidinium cation is selected from the group consisting of 1-methyl-1-ethylpiperidinium, 1-methyl-1-n-propylpiperidinium, 1-methyl-1-n-butylpiperidinium, 1,1-diethylpiperidinium, 1-ethyl-1-n-propylpiperidinium, 1-ethyl-1-n-butylpiperidinium, and any combination thereof, preferably selected from the group consisting of 1-methyl-1-n-propylpiperidinium, 1-methyl-1-n-butylpiperidinium, 1-ethyl-1-n-propylpiperidinium, and any combination thereof. 8. The process according to any one of the embodiments 1 to 7, wherein the organic structure directing agent is in the form of a salt of the piperidinium cation, and preferably the counter ion contained in the organic structure directing agent is selected from the group consisting of halides, hydroxides, sulfates, nitrates and carboxylates, more preferably from the group consisting of fluorides, chlorides, bromides, hydroxides, sulfates, nitrates and acetates, more preferably from the group consisting of chlorides, bromides, hydroxides and sulfates, more preferably from the group consisting of hydroxides, chlorides or bromides, and more preferably the hydroxide of the piperidinium cation is used. 9. The process according to any of the preceding embodiments, wherein the organic structure directing agent is present in the synthesis mixture in a piperidinium:YO2 molar ratio relative to the source of YO2, calculated as YO2, in the range of 0.01 to 1.0, preferably 0.03 to 0.5, more preferably 0.03 to 0.2, more preferably 0.05 to 0.15. 10. The process of any one of embodiments 1-9, wherein X is selected from the group consisting of Al, B, In, Ga, and any combination thereof; and Y is selected from the group consisting of Si, Sn, Ti, Zr, Ge, and any combination thereof. 11. The process of embodiment 10, wherein X is Al and Y is Si. 12. The source of X2O3 is selected from the group consisting of alumina, aluminum hydroxide, aluminate, aluminum alkoxide, aluminum salt, FAU zeolite, LTA zeolite, LTL zeolite, BEA zeolite, MFI zeolite, and any combination thereof, preferably selected from the group consisting of alumina, aluminum alkoxide, aluminum salt, FAU zeolite, and any combination thereof, more preferably selected from the group consisting of alumina, AlO(OH), Al(OH)3, aluminum tri(C1-C5)alkoxide, aluminum halide, aluminum sulfate, aluminum phosphate, aluminum fluorosilicate, FAU zeolite, and any combination thereof. 12. The process according to any one of the preceding embodiments, wherein the source of X2O3 is selected from the group consisting of: faujasite, [Al-Ge-O]-FAU, [Al-Ge-O]-FAU, [Ga-Al-Si-O]-FAU, [Ga-Ge-O]-FAU, [Ga-Si-O]-FAU, CSZ-1, Na-X, US-Y, ECR-30, LZ-210, Li-LSX, SAPO-37, Na-Y, ZSM-20, ZSM-3, zeolite X, and zeolite Y, more preferably from the group consisting of faujasite, Na-X, zeolite X, zeolite Y, US-Y, and LZ-210, and more preferably zeolite Y is the source of X2O3. 13. The process according to any one of the preceding embodiments, wherein the source of X2O3 and YO2 comprises a FAU zeolite, in particular zeolite Y, more preferably zeolite Y having a molar ratio of XO2 to Y2O3 of 40 or less, preferably 30 or less, more preferably 20 or less, even more preferably 10 or less. 14. The process of embodiment 13, wherein an additional source of YO2 is used, the additional source of YO2 being preferably selected from the group consisting of fumed silica, precipitated silica, silica hydrosol, silica gel, and colloidal silica (including mixtures of two or more thereof). 15. The source of YO2 is selected from the group consisting of fumed silica, precipitated silica, silica hydrosol, silica gel, colloidal silica, silicic acid, silicon alkoxides, alkali metal silicates, sodium metasilicate hydrate, sesquisilicates, disilicates, silicate esters, FAU zeolites, LTA zeolites, LTL zeolites, BEA zeolites, MFI zeolites, and any combination thereof, preferably fumed silica, precipitated silica, silica hydrosol, silica gel, colloidal silica faujasite, [Al-Ge-O]-FAU, [Al-Ge-O]-FAU, [Ga-Al- 15. The process according to any one of the preceding embodiments, wherein the silica is selected from the group consisting of [Si-O]-FAU, [Ga-Ge-O]-FAU, [Ga-Si-O]-FAU, CSZ-1, Na-X, US-Y, ECR-30, LZ-210, Li-LSX, SAPO-37, Na-Y, ZSM-20, ZSM-3, zeolite X, and zeolite Y, more preferably from the group consisting of faujasite, Na-X, zeolite X, zeolite Y, US-Y, and LZ-210, more preferably from the group consisting of fumed silica, precipitated silica, silica hydrosol, silica gel, colloidal silica, and zeolite Y. 16. The process according to any of the preceding embodiments, wherein the mixture prepared in step (1) has a YO2:X2O3 molar ratio of the source of YO2, calculated as YO2, to X2O3, calculated as X2O3, comprised between 5 and 100, preferably between 15 and 80, more preferably between 15 and 60, more preferably between 15 and 40, more preferably between 15 and 35, more preferably between 15 and 30. 17. The process according to any of the preceding embodiments, wherein the synthesis mixture does not contain any organic structure directing agent cations other than the piperidinium cation. 18. The process according to any of the preceding embodiments, wherein the mixture prepared in step (1) further comprises a source of alkali metal and / or alkaline earth metal cations (AM), preferably a source of alkali metal cations, wherein the alkali metal is preferably selected from the group consisting of Li, Na, K, Cs, and any combination thereof, more preferably the alkali metal is Na and / or K, preferably Na. 19. The process of embodiment 18, wherein the alkaline earth metal is preferably selected from the group consisting of Mg, Ca, Sr, and Ba, and any combination thereof. 20. The process according to embodiment 18 or 19, wherein the source of alkali metal and / or alkaline earth metal cation (AM) is selected from the group consisting of halides, hydroxides, sulfates, nitrates and carboxylates, more preferably from the group consisting of fluorides, chlorides, bromides, hydroxides, sulfates, nitrates and acetates, more preferably from the group consisting of chlorides, bromides, hydroxides and sulfates, more preferably from the group consisting of hydroxides, chlorides or bromides, more preferably the hydroxide of the piperidinium cation is used. 21. The process according to any of embodiments 18 to 20, wherein alkali metal and / or alkaline earth metal cations (AM) are contained in the synthesis mixture in an AM:YO2 molar ratio relative to the source of YO2 in the synthesis mixture, calculated as YO2, in the range of 0.01 to 1.0, preferably 0.1 to 1.0, more preferably 0.3 to 0.8, more preferably 0.5 to 0.7. 22. The synthesis mixture prepared in step (1) contains the anion OH - 22. The process of any one of the preceding embodiments, further comprising a source of, preferably a metal hydroxide or ammonium hydroxide, more preferably the source is selected from the group consisting of alkali metal hydroxides, alkaline earth metal hydroxides, and ammonium hydroxide. 23. Anion OH - 23. The process of embodiment 22, wherein the source of is an organic structure directing agent. 24.OH - The anion is in the synthesis mixture in the range of 0.1 to 2.0, preferably 0.2 to 1.0, more preferably 0.5 to 1.0, calculated as YO2, relative to the source of YO2. - 24. The process of embodiment 22 or 23, wherein the :YO2 molar ratio is present. 25. The process of any of the preceding embodiments, wherein the mixture prepared in step (1) further comprises at least one solvent, preferably water, more preferably deionized water. 26. The process according to embodiment 25, wherein the solvent is included in one or more of the starting materials of the synthesis mixture and / or can be added separately to the synthesis mixture. 27. The process according to any of the preceding embodiments, wherein the synthesis mixture has an H2O:YO2 molar ratio of the source of YO2, calculated as water to YO2, comprised between 3 and 100, more preferably between 10 and 80, more preferably between 20 and 70, more preferably between 30 and 60. 28. The process according to any one of the first to second embodiments, wherein the synthesis mixture prepared in step (1) further comprises seed crystals of CHA zeolite, and preferably, the seed crystals of CHA zeolite can be obtained or are obtained according to any one of the processes according to any one of the first to second embodiments and the second to third embodiments without using seed crystals. 29. The process according to any of the preceding embodiments, wherein the crystallization in step (2) is carried out at a temperature in the range of 80 to 250°C, preferably 100 to 200°C. 30. The process according to any of the preceding embodiments, wherein the crystallization in step (2) is carried out for a period ranging from 0.5 to 12 days, preferably from 1 to 6 days. 31. The process according to any of the preceding embodiments, wherein the crystallization in step (2) is carried out under autogenous pressure. 32. The process according to any of the preceding embodiments, wherein the crystallization in step (2) is carried out in a pressure vessel, preferably in an autoclave. 33. The process according to any of the preceding embodiments, wherein the crystallization in step (2) is carried out with or without stirring the synthesis mixture. 34. The process of any one of the preceding embodiments, wherein step (2) further comprises subjecting the CHA zeolite to a post-treatment procedure comprising isolating, optionally washing, and drying the CHA zeolite, wherein the isolation is preferably achieved by filtration. 35. (3) The process of any one of the preceding embodiments, further comprising calcining the as-synthesized CHA zeolite. 36. (4) One or more ionic non-framework elements contained in the CHA zeolite obtained in step (2) or (3) are converted to H + and / or NH4 + Preferably, NH4 + 36. The process of any one of the preceding embodiments, further comprising exchanging for 37. The process of embodiment 36, wherein step (4) further comprises subjecting the ion-exchanged CHA zeolite to a post-treatment procedure comprising isolating, optionally washing, and drying, and / or calcining the ion-exchanged CHA zeolite, wherein isolation is preferably achieved by filtration. 38. The process according to any of embodiments 35 to 37, wherein the calcination in step (3) and / or step (4) is carried out at a temperature in the range of 300 to 900°C, preferably 350 to 700°C, more preferably 400 to 650°C. 39. The process of any of embodiments 35-38, wherein the calcination in step (3) and / or step (4) is carried out in a gas atmosphere, the gas atmosphere preferably comprising, and more preferably consisting of, air, oxygen, nitrogen, or a mixture of two or more thereof. 40. The process of any of embodiments 35-39, wherein the calcination in step (3) and / or step (4) is carried out for a period in the range of 0.5 to 10 hours, preferably 3 to 7 hours, more preferably 4 to 6 hours. 41. A zeolite having a CHA-type framework structure obtained and / or obtainable by a process according to any of embodiments 1 to 40. 42. A zeolite having a CHA-type framework structure, preferably in as-synthesized form, comprising within its pores and / or channels piperidinium cations as defined in any of the preceding embodiments 1 to 7. The zeolite according to embodiment 41 or 42, having a YO2:X2O3 molar ratio of 43.2 or more, the YO2:X2O3 molar ratio being preferably in the range of 4 to 200, more preferably 6 to 100, more preferably 8 to 50, more preferably 10 to 35, more preferably 11 to 25, more preferably 11.5 to 20, more preferably 12 to 16, more preferably 12.5 to 15, more preferably 13 to 14. 44. The zeolite according to any one of embodiments 41 to 43, having an average crystal size of at most 2 μm, preferably at most 1.5 μm, more preferably an average crystal size in the range of 200 nm to 1.5 μm. 45.60m 2 / g or less, preferably 50m 2 / g or less, more preferably 45m 2 / g or less, and more preferably the mesopore surface area of ​​the zeolite is 1 to 50 m 2 / g, more preferably 3 to 40m 2 / g. 46. ​​At least 400m 2 / g, preferably at least 450m 2 / g, and more preferably the zeolite has a zeolite surface area (ZSA) of 450 to 650 m 2 / g, more preferably 450 to 600m 2 / g, and the zeolite surface area is preferably the BET surface area of ​​the zeolite as measured according to ISO 9277:2010. 47. The zeolite according to any one of embodiments 41 to 46, which has a phase purity of at least 90% as determined by X-ray powder diffraction (XRD) analysis, preferably at least 95% phase purity, more preferably at least 98% phase purity, more preferably at least 99% phase purity. 48. The zeolite according to any one of embodiments 41 to 47, containing less than 10%, preferably less than 5%, more preferably less than 2%, more preferably less than 1% of framework structure types other than CHA as separate phases and / or intergrowths, as determined by X-ray powder diffraction (XRD) analysis. 49. The zeolite according to any one of embodiments 41 to 48, comprising a promoter metal M. 50. The zeolite according to embodiment 49, wherein the promoter metal is selected from transition metals, alkaline earth metals, Sb, Sn, and Bi, and any combination thereof, preferably including Cu and / or Fe, preferably Cu. 51. The zeolite according to embodiment 49 or 50, wherein the promoter metal consists of Cu and / or Fe, preferably Cu. 52. The zeolite of any one of embodiments 49 to 51, wherein a promoter metal is contained within the zeolite and / or on the surface of the zeolite. 53. The zeolite of any one of embodiments 49 to 52, wherein the promoter metal is contained in the ion-exchange sites of the zeolite. 54. The zeolite according to any one of embodiments 49 to 53, comprising a promoter metal in an amount ranging from 0.1 to 10% by weight, preferably from 0.5 to 10% by weight, calculated as the oxide of the promoter metal, based on the total weight of the zeolite. 55. The zeolite according to any one of embodiments 49 to 54, wherein copper and / or iron are used as promoter metals, and the promoter metals are contained in the zeolite in an amount, calculated as CuO and / or Fe2O3, comprised between 1 and 8% by weight, preferably between 2 and 7% by weight, based on the total weight of the zeolite. 56. The zeolite according to any one of embodiments 49 to 55, wherein the M:X molar ratio of promoter metal to trivalent element X in the zeolitic material is in the range of 0.01 to 2, preferably 0.03 to 1.8, more preferably 0.05 to 1.5, more preferably 0.08 to 1.2, more preferably 0.1 to 1.0, more preferably 0.13 to 0.8, more preferably 0.15 to 0.5, more preferably 0.18 to 0.4, more preferably 0.2 to 0.38, more preferably 0.23 to 35, more preferably 0.25 to 32, more preferably 0.28 to 0.3. 57. 120,000h in a test gas stream consisting of 500vppm NO, 500vppm NH, 5% H, 10% O, and the balance N -1 57. A zeolite comprising a promoter metal as defined in any one of embodiments 49 to 56, which exhibits a NOx conversion of at least 11% at 200° C. and at least 50% at 575° C. when steam aged with 10% HO at 820° C. at a gas hourly space velocity (GHSV). 58. A catalyst article in the form of an extrudate comprising an SCR catalyst composition or in the form of a monolith comprising a washcoat containing an SCR catalyst composition on a substrate, the SCR catalyst composition comprising a zeolite comprising a promoter metal as described in any of embodiments 49 to 57. 59. An exhaust gas treatment system comprising an internal combustion engine and an exhaust gas conduit in fluid communication with the internal combustion engine, wherein the catalytic article of embodiment 58 is present in the exhaust gas conduit. 60. Use of a zeolite having a CHA-type framework structure according to any of embodiments 41 to 57 in a catalyst for the selective catalytic reduction of nitrogen oxides. 61. A process for selective catalytic reduction of nitrogen oxides, comprising: (A) providing a gas stream comprising nitrogen oxides (NOx); (B) contacting the gas stream with a zeolite comprising a promoter metal as defined in any one of embodiments 49-57 or a catalyst article as defined in embodiment 58.

[0098] The present invention is further illustrated by the following examples which set forth particularly advantageous embodiments. The examples are provided to illustrate the invention, but are not intended to limit the invention. EXAMPLES

[0099] Scanning electron microscopy (SEM) measurements were carried out by a scanning electron microscope (Hitachi SU1510).

[0100] X-ray powder diffraction (XRD) patterns were obtained using PANalytical X'pert 3 Data were collected in Bragg-Brentano geometry using a Powder Diffractometer (40 kV, 40 mA) measuring with CuKα (λ=1.5406 Å) radiation.

[0101] Example 1 Preparation of Zeolite with 1-Methyl-1-n-propylpiperidinium Hydroxide as OSDA (Zeolite A, Calcined H-form) 814.6 g of 1-methyl-1-n-propylpiperidinium hydroxide aqueous solution (12.6 wt%) was mixed with 2814.3 g of deionized water, followed by the addition of 110.8 g of sodium hydroxide (99%, solid). After the sodium hydroxide was dissolved, 44.9 g of Zeolite HY (SAR=7.2, from Shandong Duoyou) and 567.6 g of Ludox® AS-40 colloidal silica were added. After stirring at room temperature for 30 min, the synthesis mixture was transferred to an autoclave equipped with a Teflon liner for crystallization. Crystallization was carried out under static conditions at 150°C for 5 days. After cooling to room temperature, the zeolite product was collected by filtration and dried at 120°C overnight. Elemental analysis of the as-synthesized zeolite shows 11.51% C and 1.46% N (C / N molar ratio=9.17).

[0102] The as-synthesized zeolite was calcined at 550°C for 6 h to remove the organic structure directing agent. The calcined zeolite was crushed and ion-exchanged in 10 wt% NH4Cl aqueous solution with a solid / liquid ratio of 1:10. The ion-exchange process was carried out at 80°C for 2 h, collected by filtration, washed with deionized water, and dried at 110°C overnight. The ion-exchange procedure was repeated once, and the dried product was calcined at 450°C for 6 h to obtain the calcined H-type zeolite.

[0103] The zeolite has a SiO2 / Al2O3 molar ratio of 14.2 (SAR) as measured by XRF for the calcined H-form and 20mM (SAR) as measured for the calcined H-form. 2 / g mesopore surface area (MSA) and 508 m 2 / g zeolite surface area (ZSA).

[0104] The crystal morphology of the zeolite observed from the SEM image and XRD pattern of the zeolite are shown in Figures 1 and 2, respectively. The XRD pattern confirmed that the zeolite has a typical CHA framework.

[0105] Example 2 Preparation of Zeolite with 1-Methyl-1-n-propylpiperidinium Hydroxide as OSDA (Zeolite B, Calcined H-form) 500.1 g of 1-methyl-1-n-propylpiperidinium hydroxide aqueous solution (12.6 wt%) was mixed with 2628.2 g of deionized water, followed by the addition of 169.8 g of sodium hydroxide (99%, solid). After the sodium hydroxide was dissolved, 103.3 g of Zeolite HY (SAR=7.2, from Shandong Duoyou) and 811.8 g of Ludox® AS-40 colloidal silica were added. After stirring at room temperature for 30 min, the synthesis mixture was transferred to an autoclave equipped with a Teflon liner for crystallization. Crystallization was carried out under static conditions at 150°C for 3 days. After cooling to room temperature, the zeolite product was collected by filtration and dried at 120°C overnight. Elemental analysis of the as-synthesized zeolite shows 9.88% C and 1.32% N (C / N molar ratio=8.73).

[0106] The as-synthesized zeolite was calcined at 550°C for 6 h to remove the organic structure directing agent. The calcined zeolite was crushed and ion-exchanged in 10 wt% NH4Cl aqueous solution with a solid / liquid ratio of 1:10. The ion-exchange process was carried out at 80°C for 2 h, collected by filtration, washed with deionized water, and dried at 110°C overnight. The ion-exchange procedure was repeated once, and the dried product was calcined at 450°C for 6 h to obtain the calcined H-type zeolite.

[0107] The zeolite has a SiO2 / Al2O3 molar ratio of 12.5 (SAR) as measured by XRF for the calcined H-form and 12m 2 / g mesopore surface area (MSA) and 531 m 2 / g zeolite surface area (ZSA).

[0108] The crystal morphology of the zeolite observed from the SEM image and XRD pattern of the zeolite are shown in Figures 1 and 2, respectively. The XRD pattern confirmed that the zeolite has a typical CHA framework.

[0109] Example 3 Preparation of Zeolite with 1-Methyl-1-n-propylpiperidinium Hydroxide as OSDA (Zeolite C, Calcined H-form) 500.1 g of 1-methyl-1-n-propylpiperidinium hydroxide aqueous solution (12.6 wt%) was mixed with 2472.2 g of deionized water, followed by the addition of 169.8 g of sodium hydroxide (99%, solid). After the sodium hydroxide was dissolved, 103.3 g of Zeolite HY (SAR=7.2, from Sinopec) and 811.8 g of sodium silicate were added. After stirring at room temperature for 30 minutes, the synthesis mixture was transferred to an autoclave equipped with a Teflon liner for crystallization. Crystallization was carried out under static conditions at 150°C for 3 days. After cooling to room temperature, the zeolite product was collected by filtration and dried at 120°C overnight.

[0110] The as-synthesized zeolite was calcined at 550°C for 6 h to remove the organic structure directing agent. The calcined zeolite was crushed and ion-exchanged in 10 wt% NH4Cl aqueous solution with a solid / liquid ratio of 1:10. The ion-exchange process was carried out at 80°C for 2 h, collected by filtration, washed with deionized water, and dried at 110°C overnight. The ion-exchange procedure was repeated once, and the dried product was calcined at 450°C for 6 h to obtain the calcined H-type zeolite.

[0111] The zeolite has a SiO2 / Al2O3 molar ratio of 11.5 (SAR) as measured by XRF for the calcined H-form and 10m 2 / g mesopore surface area (MSA) and 545 m 2 / g zeolite surface area (ZSA).

[0112] The crystal morphology of the zeolite observed from the SEM image and XRD pattern of the zeolite are shown in Figures 1 and 2, respectively. The XRD pattern confirmed that the zeolite has a typical CHA framework.

[0113] Example 4 Preparation of Zeolite with 1-Methyl-1-n-Butyl-Piperidinium Hydroxide as OSDA (Zeolite D, Calcined H-form) 718.4 g of 1-methyl-1-n-butyl-piperidinium hydroxide aqueous solution (9.7 wt%) was mixed with 2431.6 g of deionized water, followed by the addition of 172.7 g of sodium hydroxide (99%, solid). After the sodium hydroxide was dissolved, 69.9 g of Zeolite HY (SAR=7.2, from Shandong Duoyou) and 884.4 g of Ludox® AS-40 colloidal silica were added. After stirring at room temperature for 30 minutes, the synthesis mixture was transferred to an autoclave equipped with a Teflon liner for crystallization. Crystallization was carried out under static conditions at 150°C for 3 days. After cooling to room temperature, the zeolite product was collected by filtration and dried at 120°C overnight.

[0114] The as-synthesized zeolite was calcined at 550°C for 6 h to remove the organic structure directing agent. The calcined zeolite was crushed and ion-exchanged in 10 wt% NH4Cl aqueous solution with a solid / liquid ratio of 1:10. The ion-exchange process was carried out at 80°C for 2 h, collected by filtration, washed with deionized water, and dried at 110°C overnight. The ion-exchange procedure was repeated once, and the dried product was calcined at 450°C for 6 h to obtain the calcined H-type zeolite.

[0115] The zeolite has a SiO2 / Al2O3 molar ratio of 13.9 (SAR) as measured by XRF for the calcined H-form and 37m 2 / g mesopore surface area (MSA) and 515 m 2 / g zeolite surface area (ZSA).

[0116] The crystal morphology of the zeolite observed from the SEM image and XRD pattern of the zeolite are shown in Figures 1 and 2, respectively. The XRD pattern confirmed that the zeolite has a typical CHA framework.

[0117] Example 5 Preparation of Zeolite with 1-Ethyl-1-n-propylpiperidinium Hydroxide as OSDA (Zeolite E, Calcined H-form) 893.5g of 1-ethyl-1-n-propylpiperidinium hydroxide aqueous solution (7.9 wt%) was mixed with 2335.3g of deionized water, followed by the addition of 169.5g of sodium hydroxide (99%, solid). After the sodium hydroxide was dissolved, 106.5g of Zeolite HY (SAR=7.2, from Shandong Duoyou) and 836.4g of Ludox® AS-40 colloidal silica were added. After stirring at room temperature for 30 minutes, the synthesis mixture was transferred to an autoclave equipped with a Teflon liner for crystallization. Crystallization was carried out under static conditions at 150°C for 3 days. After cooling to room temperature, the zeolite product was collected by filtration and dried at 120°C overnight.

[0118] The as-synthesized zeolite was calcined at 550°C for 6 h to remove the organic structure directing agent. The calcined zeolite was crushed and ion-exchanged in 10 wt% NH4Cl aqueous solution with a solid / liquid ratio of 1:10. The ion-exchange process was carried out at 80°C for 2 h, collected by filtration, washed with deionized water, and dried at 110°C overnight. The ion-exchange procedure was repeated once, and the dried product was calcined at 450°C for 6 h to obtain the calcined H-type zeolite.

[0119] The zeolite has a SiO2 / Al2O3 molar ratio of 12.3 (SAR) as measured by XRF for the calcined H-form and 20mM as measured for the calcined H-form. 2 / g mesopore surface area (MSA) and 530 m 2 / g zeolite surface area (ZSA).

[0120] The crystal morphology of the zeolite observed from the SEM image and XRD pattern of the zeolite are shown in Figures 1 and 2, respectively. The XRD pattern confirmed that the zeolite has a typical CHA framework.

[0121] Example 6 Preparation of Zeolite with N,N,N-Trimethyl-1-Adamantylammonium Hydroxide as OSDA (Zeolite F, Calcined H-form) To a solution of 0.5 g sodium hydroxide (99%, solid) in 35 g DI water, 95 g sodium silicate, 3 g sodium sulfate (99%, solid) and then 9 g zeolite Na-Y (SAR=5.1, CBV 100 from Zeolyst) were added. Then, 16 g of N,N,N-trimethyl-1-adamantylammonium hydroxide aqueous solution (20 wt%) was added and stirred at room temperature for 30 minutes. The synthesis mixture was then transferred to an autoclave equipped with a Teflon liner for crystallization. Crystallization was carried out under static conditions at 140° C. for 3 days. After cooling to room temperature, the zeolite product was collected by filtration and dried at 120° C. overnight.

[0122] The as-synthesized zeolite was calcined at 550°C for 6 h to remove the organic structure directing agent. The calcined zeolite was crushed and ion-exchanged in 10 wt% NH4Cl aqueous solution with a solid / liquid ratio of 1:10. The ion-exchange process was carried out at 80°C for 2 h, collected by filtration, washed with deionized water, and dried at 110°C overnight. The ion-exchange procedure was repeated once, and the dried product was calcined at 450°C for 6 h to obtain the calcined H-type zeolite.

[0123] The zeolite has a SiO2 / Al2O3 molar ratio of 11.4 (SAR) as measured by XRF for the calcined H-form and 11m 2 / g mesopore surface area (MSA) and 512 m 2 / g zeolite surface area (ZSA).

[0124] The crystal morphology of the zeolite observed from the SEM image and XRD pattern of the zeolite are shown in Figures 1 and 2, respectively. The XRD pattern confirmed that the zeolite has a typical CHA framework.

[0125] Example 7 Preparation of Zeolites with 1,1-Dimethylpiperidinium Hydroxide as the OSDA (Zeolite G, Calcined H-form) 16.4 g of 1,1-dimethylpiperidinium hydroxide aqueous solution (20 wt%) was mixed with 9.7 g of deionized water, followed by the addition of 3.0 g of sodium hydroxide (99%, solid). After the sodium hydroxide was dissolved, 2.0 g of Zeolite HY (SAR=7.2, from Shandong Duoyou) and 16.8 g of Ludox® AS-40 colloidal silica were added. After stirring at room temperature for 30 minutes, the synthesis mixture was transferred to an autoclave equipped with a Teflon liner for crystallization. Crystallization was carried out under static conditions at 170°C for 2 days. After cooling to room temperature, the zeolite product was collected by filtration and dried at 120°C overnight.

[0126] The as-synthesized zeolite was calcined at 550°C for 6 h to remove the organic structure directing agent. The calcined zeolite was crushed and ion-exchanged in 10 wt% NH4Cl aqueous solution with a solid / liquid ratio of 1:10. The ion-exchange process was carried out at 80°C for 2 h, collected by filtration, washed with deionized water, and dried at 110°C overnight. The ion-exchange procedure was repeated once, and the dried product was calcined at 450°C for 6 h to obtain the calcined H-type zeolite.

[0127] As confirmed by XRD, a zeolite with LEV framework was obtained. It was found that when 1,1-dimethylpiperidinium hydroxide was used as the OSDA according to this synthesis method, a zeolite with CHA type framework could not be obtained.

[0128] Example 8 Preparation of Cu-loaded CHA-type zeolite material (SCR catalyst) The as-obtained H-type zeolite powder was impregnated with an aqueous solution of copper(II) nitrate by incipient wetness impregnation and kept in a closed vessel at 50° C. for 20 h. The obtained solid was dried and calcined in a furnace at 450° C. for 5 h in air to obtain Cu-loaded CHA zeolite.

[0129] The Cu-loaded CHA zeolites prepared according to the general procedure above are summarized in Table 2 below.

[0130] [Table 2]

[0131] Example 9 Catalytic performance test To test the SCR performance, the Cu-loaded zeolite material was slurried with an aqueous Zr acetate solution, then dried under stirring in air at ambient temperature and calcined at 550°C for 1 h to obtain a product containing 5 wt% ZrO2 as binder based on the amount of product. The product was crushed and the powder fraction of 250-500 microns was used for testing. The resulting powder was aged in a 10 vol% steam / air flow at 650°C for 50 h or 820°C for 16 h to obtain aged samples.

[0132] Selective catalytic reduction (SCR) tests were carried out in a fixed bed reactor packed with 80 mg of test sample in a bed volume of approximately 1 mL with corundum of the same sieve fraction as diluent according to the following conditions:

[0133] [Table 3]

[0134] NOx conversion as measured from run 2 at 200° C. and 575° C. is reported as the test results.

[0135] The results for the test samples aged at 650° C. and 820° C. are summarized in Table 3 below.

[0136] [Table 4]

[0137] Catalysts comprising Cu-loaded CHA zeolites according to the present invention are found to be effective for selective catalytic reduction (SCR) of nitrogen oxides after aging at high temperatures.

[0138] When aged at 650°C, the catalysts of the invention based on CHA zeolites A-E prepared with piperidinium cation-based OSDAs (Examples 1-5) show at least comparable NOx conversion compared to comparative catalyst F (Example 6) prepared with the same Cu / Al ratio but a different OSDA.

[0139] Surprisingly, when aged at 820° C., the inventive catalysts show significantly improved NOx conversion compared to Comparative Catalyst F. The inventive catalysts aged at 820° C. provide at least 11% and even up to 75% NOx conversion at 200° C. and at least 56% and even up to 89% NOx conversion at 575° C., compared to “0” NOx conversion for the corresponding Comparative Catalyst. The relatively high SCR activity of the inventive catalysts after aging at 820° C. reflects the high stability of CHA zeolite at extremely high temperatures.

[0140] Moreover, it was surprisingly found from the catalytic tests in SCR that the hydrothermal stability of the samples of the invention may depend on both the SiO2:Al2O3 molar ratio and the Cu:Al molar ratio, depending on the particular template used. Thus, as can be seen from the results shown in Table 3 for catalyst samples A-C, the hydrothermal stability gradually decreases with decreasing SiO2:Al2O3 molar ratio, where the SiO2:Al2O3 molar ratio decreases from 14.2 to 11.5 for samples A to C. In addition, as can be seen from the results for zeolite C, an increase in the Cu:Al molar ratio from 0.32 for sample no. C.1 to 0.4 for sample no. C.3 leads to a dramatic decrease in hydrothermal stability, as can be observed by the NOx conversion after aging at 820°C.

[0141] In addition, a sulfidation resistance test was carried out on the catalyst containing the Cu-supported CHA-type zeolite according to the present invention according to the following procedure.

[0142] sulfide A piece of Pt-containing diesel oxidation catalyst (DOC, 0.6 wt% Pt supported on aluminosilicate) with dimensions of 3 inches (diameter) x 2 inches (length) was placed upstream of 200 mg of Cu-supported CHA catalyst powder in a column reactor. A gas stream containing 8 vol% H2O, 10 vol% O2, 7 vol% CO2, and balance N2 was fed through the reactor with heating at 10 K / min and maintained at a temperature of 400 °C for 1 hour. The feed was then cooled to 10,000 hr based on the volume of SCR catalyst. -1 Space velocity of 35 ppmv SO2, 10 vol% O2, 8 vol% H2O, 7 vol% CO 2、 % H2O, 10 vol.% O2, 7 vol.% CO2, and balance N2 for a time to produce 22.7 mg of S per 100 mg of sample. The reactor was cooled to 150° C. by switching the feed to a gas stream containing 8 vol.% H2O, 10 vol.% O2, 7 vol.% CO2, and balance N2, and then cooled by switching the feed to a gas stream containing 10 vol.% O2 and balance N2.

[0143] Desulfurization (regeneration) A gas stream containing 10% by volume O, 8% by volume H2O, 7% by volume CO2, and the balance N2 was passed through a space velocity of 60,000 h -1 The desulfurized SCR catalyst was obtained by passing the mixture through the sulfided SCR catalyst at 550° C. for 30 minutes. The reactor was cooled in the same manner as described for the sulfidation.

[0144] The SCR test was carried out in a fixed bed reactor packed with 120 mg of test sample in a bed volume of approximately 1 mL with the same sieve fraction of corundum as diluent, using a gas feed of 500 vppm NO, 525 vppm NH, 8 vol.% H2O, 10 vol.% O2, 7 vol.% CO2, and the balance N2 for 60,000 h. -1 The results are summarized in Table 4 below.

[0145] [Table 5]

[0146] The catalysts containing Cu-loaded CHA zeolite according to the invention show acceptable sulfidation resistance. With regard to the results obtained for sample number C.2 after aging at 820°C, reference is made to the effects described in the previous chapter in relation to the results shown in Table 4, as well as the dependence of the hydrothermal stability of the samples according to the invention on both the SiO2:Al2O3 molar ratio and the Cu:Al molar ratio.

[0147] Example 10 Preparation of Fe-supported CHA-type zeolite and catalytic performance test Two Fe-loaded CHA zeolites were prepared according to the same process as described in Example 8, except that Fe-loaded zeolites were obtained using aqueous iron(III) nitrate solution for incipient wetness impregnation. The prepared Fe-loaded CHA zeolites are summarized in Table 5 below.

[0148] [Table 6]

[0149] A test sample of a catalyst containing Fe-loaded CHA zeolite was prepared following the same process as described in Example 9, except that the powder was aged at 650° C. for 50 hours.

[0150] The SCR test was carried out in a fixed bed reactor with 120 mg of test sample packed in a bed volume of approximately 1 mL with corundum of the same sieve fraction as diluent according to the following conditions:

[0151] [Table 7]

[0152] The results are summarized in Table 6 below.

[0153] [Table 8]

[0154] It is found that catalysts containing Fe-loaded CHA zeolites are also effective for selective catalytic reduction of NOx after aging at high temperatures and exhibit acceptable sulfidation resistance.

Claims

1. A process for preparing a zeolite having a CHA-type framework structure, wherein the framework structure is X ２ O ３ and Y.O. ２ wherein X is a trivalent element and Y is a tetravalent element; （１） (A) X ２ O ３ Source of, (B)YO ２ Sources of, and (C) a source of piperidinium cations represented by formula (I) as an organic structure directing agent (OSDA), 【Chemical 1】 During the ceremony, R １ａ is C １ ~C ８ Alkyl and C ３ ~C １０ cycloalkyl; R １ｂ is C ２ ~C ８ Alkyl and C ３ ~C １０ cycloalkyl; R ２ , R ３ , R ４ , R ５ , and R ６ are, independently of each other, H, hydroxyl, or C １ ~C ８ preparing a synthesis mixture containing a source that is an alkyl; (2) subjecting said synthesis mixture to crystallization conditions to form a CHA zeolite.

2. The piperidinium cation is represented by the following formula (I): R １ａ is C １ ~C ８ Alkyl and C ３ ~C １０ cycloalkyl; R １ｂ is C ３ ~C ８ Alkyl and C ３ ~C １０ cycloalkyl; R ２ , R ３ , R ４ , R ５ , and R ６ are, independently of each other, H, hydroxyl, or C １ ~C ８ The process of claim 1 wherein the alkyl group is alkyl.

3. The piperidinium cation is represented by formula (Ia): 【Chemistry 2】 During the ceremony, R １ａ is C １ ~C ５ Alkyl and C ５ ~C １０ cycloalkyl; R １ｂ is C ３ ~C ５ Alkyl and C ５ ~C １０ cycloalkyl; R ３ , R ４ , and R ５ are, independently of each other, H, hydroxyl, or C １ ~C ５ 3. The process of claim 2, wherein the alkyl is alkyl.

4. The piperidinium cation is represented by formula (Ia), wherein R １ａ is C １ ~C ５ alkyl, and R １ｂ is C ３ ~C ５ alkyl, and R ３ , R ４ , and R ５ are, independently of each other, H, hydroxyl, or C １ ~C ５ The process of claim 3 wherein the alkyl is alkyl.

5. The piperidinium cation is represented by formula (Ia), wherein R １ａ is C １ ~C ３ alkyl, and R １ｂ is C ３ ~C ５ alkyl, and R ３ and R ５ are each independently H or C １ ~C ５ alkyl, and R ４ The process of claim 4 , wherein

6. The piperidinium cation is represented by formula (Ia), wherein R １ａ is C １ ~C ３ alkyl, and R １ｂ is C ３ ~C ５ alkyl, and R ３ , R ４ , and R ５ The process of claim 5 , wherein

7. 7. The process of claim 6, wherein the piperidinium cation is selected from the group consisting of 1-methyl-1-ethylpiperidinium, 1-methyl-1-n-propylpiperidinium, 1-methyl-1-n-butylpiperidinium, 1,1-diethylpiperidinium, 1-ethyl-1-n-propylpiperidinium, 1-ethyl-1-n-butylpiperidinium, and any combination thereof, preferably selected from the group consisting of 1-methyl-1-n-propylpiperidinium, 1-methyl-1-n-butylpiperidinium, 1-ethyl-1-n-propylpiperidinium, and any combination thereof.

8. The organic structure directing agent is in the range of 0.01 to 1.0, preferably 0.03 to 0.5, more preferably 0.03 to 0.2, more preferably 0.05 to 0.15, ２ YO calculated as ２ Piperidinium for a source of: YO ２ The process of any one of claims 1 to 7, wherein the molar ratio of hydroxybenzoates to hydroxybenzoates is 0.01 to 0.

01.

9. 8. The process of any one of claims 1 to 7, wherein X is selected from the group consisting of Al, B, In, Ga, and any combination thereof, and Y is selected from the group consisting of Si, Sn, Ti, Zr, Ge, and any combination thereof.

10. 10. The process of claim 9, wherein X is Al and Y is Si.

11. X ２ O ３ and Y.O. ２ is preferably a FAU zeolite, in particular zeolite Y, more preferably an XO of 40 or less, preferably 30 or less, more preferably 20 or less, even more preferably 10 or less ２ Against Y ２ O ３ 8. The process of claim 1, wherein the zeolite Y has a molar ratio of:

12. YO ２ an additional source of YO is used; ２ 12. The process of claim 11, wherein the additional source of silica is preferably selected from the group consisting of fumed silica, precipitated silica, silica hydrosol, silica gel, and colloidal silica (including mixtures of two or more thereof).

13. The process of any one of claims 1 to 7, wherein the synthesis mixture does not contain any organic structure directing agent cations other than the piperidinium cation.

14. 10. A zeolite having a CHA-type framework structure obtained and / or obtainable by the process of claim 1.

15. A zeolite having a CHA-type framework structure, preferably in as-synthesized form, comprising within its pores and / or channels the piperidinium cations according to any one of claims 1 to 7.

16. 2 or more YO ２ :X ２ O ３ The molar ratio of YO ２ :X ２ O ３ 15. The zeolite according to claim 14, wherein the molar ratio is preferably comprised between 4 and 200, more preferably between 6 and 100, more preferably between 8 and 50, more preferably between 10 and 35, more preferably between 11 and 25, more preferably between 11.5 and 20, more preferably between 12 and 16, more preferably between 12.5 and 15.

17. 15. The zeolite of claim 14, wherein the zeolite comprises a promoter metal M.

18. 18. The zeolite of claim 17, wherein the promoter metal is selected from transition metals, alkaline earth metals, Sb, Sn, and Bi, and any combination thereof, preferably comprising Cu and / or Fe, preferably Cu.

19. 18. The zeolite of claim 17, wherein the promoter metal consists of Cu and / or Fe, preferably Cu.

20. 18. The zeolite of claim 17, wherein the promoter metal is contained within the zeolite and / or on the surface of the zeolite.

21. 18. The zeolite of claim 17, wherein the M:X molar ratio of said promoter metal to said trivalent element X in the zeolitic material is comprised between 0.01 and 2, preferably between 0.03 and 1.8, more preferably between 0.05 and 1.5, more preferably between 0.08 and 1.2, more preferably between 0.1 and 1.0, more preferably between 0.13 and 0.8, more preferably between 0.15 and 0.5, more preferably between 0.18 and 0.4, more preferably between 0.2 and 0.38, more preferably between 0.23 and 35, more preferably between 0.25 and 32, more preferably between 0.28 and 0.

3.

22. 500 vppm NO, 500 vppm NH ３ , 5 vol% H ２ O, 10% by volume O ２ , and the remaining N ２ 120,000h in a test gas flow consisting of －１ at 820°C with 10% H ２ 20. The zeolite comprising the promoter metal of claim 17, which upon steam aging with O exhibits a NOx conversion of at least 11% at 200°C and at least 50% at 575°C.

23. 20. A catalyst article in the form of an extrudate comprising an SCR catalyst composition or in the form of a monolith comprising a washcoat containing an SCR catalyst composition on a substrate, wherein the SCR catalyst composition comprises a zeolite comprising the promoter metal of claim 17.

24. 24. An exhaust gas treatment system comprising an internal combustion engine and an exhaust gas conduit in fluid communication with said internal combustion engine, wherein the catalytic article of claim 23 is present in said exhaust gas conduit.

25. 15. Use of a zeolite having a CHA-type framework structure according to claim 14 in a catalyst for the selective catalytic reduction of nitrogen oxides.

26. A process for the selective catalytic reduction of nitrogen oxides, comprising: (A) providing a gas stream comprising nitrogen oxides (NOx); (B) contacting the gas stream with a zeolite containing a promoter metal of claim 17 or a catalyst article of claim 23.

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