Method for preparing molecular sieves using 1,1-diethyl-2,6-dimethylpiperidin-1-ium and molecular sieves prepared therefrom

Abstract

Disclosed herein is a method for preparing a molecular sieve, comprising forming a synthesis gel containing an aluminum source, a silicon source, an organic structure directing agent, water, an alkali source, and optionally seed crystals; and heating the synthesis gel to obtain a molecular sieve, wherein the organic structure directing agent comprises 1,1-diethyl-2,6-dimethylpiperidin-1-ium cations, and the molecular sieve comprises a framework type that is not AEI. Also disclosed are molecular sieves prepared according to the disclosed methods, selective catalytic reduction catalysts comprising the disclosed molecular sieves, and methods for selective catalytic reduction using the disclosed selective catalytic reduction catalysts.

Description

[Technical Field]

[0001] Disclosed herein is a method for preparing a molecular sieve, comprising forming a synthesis gel containing an aluminum source, a silicon source, an organic structure directing agent, water, an alkali source, and optionally seed crystals; and heating the synthesis gel to obtain a molecular sieve, wherein the organic structure directing agent comprises 1,1-diethyl-2,6-dimethylpiperidin-1-ium cations, and the molecular sieve comprises a framework type that is not AEI. Also disclosed are molecular sieves prepared according to the disclosed methods, selective catalytic reduction catalysts comprising the disclosed molecular sieves, and methods for selective catalytic reduction using the disclosed selective catalytic reduction catalysts. [Background technology]

[0002] Internal combustion engines, combustion equipment, and nitric acid production plants produce nitrogen oxides (NO x )-containing gas mixtures, creating air pollution that can contribute to environmental health hazards such as smog and acid rain. Various methods, including catalytic reduction of nitrogen oxides, can be used to reduce NO x For example, carbon monoxide, hydrogen, or lower hydrocarbons can be reduced by non-selective NO x Alternatively, ammonia or an ammonia precursor (e.g., urea) can be used as a reducing agent in a selective NO reduction process called selective catalytic reduction (SCR). x It can be used as a reducing agent in the reduction process. In SCR, a high degree of nitrogen oxide removal can be achieved using a small amount of reducing agent.

[0003] Molecular sieves have been used as catalysts for SCR and other reactions, including the methanol-to-olefins (MTO) reaction. Molecular sieves are aluminosilicate materials with a substantially regular porous structure, with typical pore sizes ranging from 3 to 10 Å in diameter, that can be useful as catalysts. Illustratively, certain molecular sieves with eight-ring pore openings and double six-ring secondary building blocks have been used as SCR catalysts. One example of a molecular sieve framework is chabazite (CHA), a small-pore molecular sieve structure with eight-ring pore openings accessible through its three-dimensional porosity. The connection of the double six-ring building blocks by four rings gives chabazite a cage-like structure. AEI and AFX-type molecular sieves are alternative, non-limiting examples of small-pore cage molecular sieves that can also be useful in catalysts, including those for the selective reduction of nitrogen oxides.

[0004] Novel synthetic routes and molecular sieve morphologies can result in molecular sieves with improved performance in SCR and / or other applications. The selection of a molecular sieve synthetic route can affect the structure, stability, and / or activity of the resulting molecular sieve. Illustratively, the defect density in the molecular sieve framework can affect the hydrothermal stability and / or catalytic activity of the molecular sieve.

[0005] Selective catalytic reduction catalysts are typically exposed to high temperature hydrothermal conditions, under which the activity of transition metal ion-exchanged molecular sieves can decrease.

[0006] Thus, for example, there is a need for molecular sieves with improved selective catalytic reduction and improved methods for preparing the same. Summary of the Invention

[0007] A method for preparing a molecular sieve is disclosed, comprising forming a synthesis gel containing an aluminum source, a silicon source, an organic structure directing agent, water, an alkali source, and optionally seed crystals; and heating the synthesis gel to obtain a molecular sieve, wherein the organic structure directing agent comprises 1,1-diethyl-2,6-dimethylpiperidin-1-ium cations, and the molecular sieve comprises a framework type that is not an AEI. As used herein, the phrase "the molecular sieve comprises a framework type that is not an AEI" means that the zeolite may be primarily a framework other than an AEI, such as CHA, but preferably contains a small amount of AEI. For example, a molecular sieve comprising a framework type that is not an AEI may contain 0% to 10% AEI, or more preferably 0% to 5% AEI, as determined by peak areas from XRD.

[0008] In some embodiments, the aluminum source is selected from molecular sieve Y (faujasite), a compound of formula Al(OR), aluminum oxide, aluminum hydroxide, and combinations thereof, where R is selected from a C2-C5 alkyl group.

[0009] In some embodiments, the silicon source is selected from molecular sieve Y (faujasite), sodium silicate, colloidal silica, fumed silica, precipitated silica, and combinations thereof.

[0010] In some embodiments, the organic structure directing agent comprises 1,1-diethyl-2,6-dimethylpiperidin-1-ium hydroxide.

[0011] In some embodiments, the alkaline source comprises at least one element selected from sodium and potassium.

[0012] In some embodiments, the heating step is carried out at a temperature ranging from 100° C. to 200° C. for a duration ranging from 30 minutes to 100 hours.

[0013] In some embodiments, the molecular sieve comprises a CHA framework.

[0014] In some embodiments, the molecular sieve has a crystallinity ranging from 50% to 100%.

[0015] In some embodiments, the molecular sieve comprises 50% to 100% CHA framework type by total crystalline phase intensity as determined by X-ray diffraction.

[0016] In some embodiments, the synthesis gel comprises seed crystals, and the seed crystals comprise a CHA framework type.

[0017] In some embodiments, the synthesis gel has one or more of the following properties: a SiO:AlO ratio in the range of 15-50; a Na:Si ratio in the range of 0.1-1; a ratio of 1,1-diethyl-2,6-dimethylpiperidin-1-ium cations to Si in the range of 0.01-0.3; an OH:Si ratio in the range of 0.1-1; and a HO:Si ratio in the range of 5-50.

[0018] In some embodiments, the molecular sieve has an average crystal size in the range of 0.1 μm to 2 μm as measured by scanning electron microscopy.

[0019] In some embodiments, the organic structure directing agent comprises a trimethyladamantylammonium cation.

[0020] In some embodiments, the molecular sieve is a Na-type molecular sieve, and the method includes ion-exchanging the Na-type molecular sieve with an aqueous ammonium solution to produce NH + obtaining a molecular sieve of the type NH4 +The method further comprises one or more steps selected from the group consisting of a step of calcining the H-type molecular sieve at a temperature ranging from 200°C to 800°C for a duration ranging from 30 minutes to 12 hours to obtain an H-type molecular sieve, a step of ion-exchanging and / or impregnating the H-type molecular sieve with a transition metal M to obtain an M-type molecular sieve, and a step of calcining the M-type molecular sieve at a temperature ranging from 200°C to 800°C for a duration ranging from 30 minutes to 12 hours.

[0021] In some embodiments, the transition metal M is selected from iron, copper, and combinations thereof.

[0022] Molecular sieves prepared according to the disclosed methods are disclosed.

[0023] A CHA molecular sieve containing 1,1-diethyl-2,6-dimethylpiperidin-1-ium is disclosed.

[0024] In some embodiments, the molecular sieve has a silica to alumina molar ratio in the range of 5 to 50, 450 m 2 / g~650m 2 / g range of molecular sieve surface area, and 5m 2 / g~50m 2 / g of matrix surface area.

[0025] A selective catalytic reduction catalyst is disclosed that includes a Cu-type molecular sieve prepared according to the disclosed method.

[0026] A method for the selective catalytic reduction of nitrogen oxides in an exhaust gas is disclosed, comprising contacting the exhaust gas with the disclosed selective catalytic reduction catalyst. [Brief explanation of the drawings]

[0027] [Figure 1] 1 shows a scanning electron microscope image of an exemplary embodiment of the present disclosure. [Figure 2]1 shows an X-ray diffraction pattern of an exemplary embodiment of the present disclosure. [Figure 3] 1 shows an X-ray diffraction pattern of an exemplary embodiment of the present disclosure. [Figure 4] 1 shows the selective catalytic reduction activity of an exemplary embodiment of the present disclosure. [Figure 5] 1 shows the selective catalytic reduction activity of an exemplary embodiment of the present disclosure. [Figure 6A] 1 shows an SEM image of Example L. [Figure 6B] 10 shows another SEM image of Example L. [Figure 7] 1 shows the X-ray diffraction pattern of Example L after calcination. DETAILED DESCRIPTION OF THE INVENTION

[0028] Definition: As used herein, "a" or "an" entity refers to one or more of that entity; for example, "a compound" refers to one or more compounds or at least one compound, unless otherwise specified. Thus, the terms "a" (or "an"), "one or more," and "at least one" are used interchangeably herein.

[0029] As used herein, the term "material" refers to elements, components, and / or substances that make up or can make something.

[0030] As used herein, the term "calcining" refers to heating a solid to an elevated temperature (i.e., above ambient temperature) in air or oxygen, such as to remove impurities or volatile materials from the solid.

[0031] As used herein, the term "aluminum source" refers to a material that contains aluminum and / or aluminum ions, such as, for example, aluminum salts, aluminum isopropoxide, and / or aluminum hydroxide.

[0032] As used herein, the term "catalyst" or "catalyst composition" refers to a molecule or material that promotes a reaction.

[0033] As used herein, the term "copper source" refers to a material that contains copper and / or copper ions, such as copper salts and / or copper complexes, such as copper-tetraethylenepentamine.

[0034] As used herein, the term "ion exchange treatment" refers to a process in which one or more ions are incorporated into and / or removed from a molecular sieve. As a non-limiting example, a molecular sieve may be subjected to a copper ion exchange treatment by mixing the molecular sieve with a copper-containing material, such as CuO, and a solution, such as an aqueous zirconium acetate solution.

[0035] As used herein, the term "molecular sieve" refers to an aluminosilicate material having a substantially ordered porous structure. In some embodiments, the molecular sieve is capable of selectively separating molecules based on size exclusion. In some embodiments, the molecular sieve is a zeolite.

[0036] As used herein, molecular sieves, e.g., zeolite framework types, are classified by the Structure Commission of the International Zeolite Association according to the rules of the IUPAC Commission on Zeolite Nomenclature, which classifies zeolite framework types by assigning them a three-letter code and are described in Atlas of Zeolite Framework Types, 5th edition, Elsevier, London, England (2001).

[0037] As used herein, the term "organic structure directing agent" refers to an organic compound that can affect the morphology and / or structure of a molecular sieve. For example, the organic structure directing agent can be an ionic organic molecule that can be incorporated into the structure of the molecular sieve. The organic structure directing agent can include, for example, a large and / or sterically bulky organic group. The organic structure directing agent can include, for example, an adamantanammonium group. Trimethyladamantylammonium is a non-limiting example of an organic structure directing agent.

[0038] As used herein, the term "reducing agent" refers to a compound that reacts with NO at elevated temperatures (i.e., temperatures above ambient temperature). x Non-limiting examples of reducing agents include ammonia, urea, and fuels.

[0039] As used herein, the term "selective catalytic reduction" (SCR) refers to a catalytic process that uses a reducing agent to reduce nitrogen oxides.

[0040] As used herein, the term "silica source" refers to a material containing silicon and / or silicon oxide, such as colloidal silica, silicates, sodium silicate, and / or Ludox AS-40.

[0041] As used herein, the term "small pore" in reference to the dimensions of a material refers to a material having pore openings smaller than 5 Å (eg, pore openings between 3 Å and 5 Å).

[0042] As used herein, the term "heat treatment" refers to a process in which a composition is subjected to elevated temperatures (ie, temperatures above ambient temperature) for a sustained period of time.

[0043] As used herein, the term "zeolite" refers to an aluminosilicate material having a substantially regular porous structure. Zeolites of the present disclosure can have many different framework structures with substantially regular porous structures of molecular dimensions. In some embodiments, zeolites of the present disclosure have an open 3D framework structure composed of corner-sharing TO4 tetrahedra, where T is Al or Si. In some embodiments, anionic framework charge-balancing non-framework cations are loosely associated with framework oxygens, and the remaining pore volume is filled with water molecules. In some embodiments, the non-framework cations are exchangeable. In some embodiments, the water molecules are removable.

[0044] The structure of the molecular sieves of the present disclosure can be analyzed using routine techniques in the art, such as, for example, X-ray diffraction (XRD). As a non-limiting example, the crystallinity of the molecular sieves of the present disclosure can be determined by XRD analysis.

[0045] As used herein, "phase crystallinity" refers to the weight percent of a particular crystalline phase relative to the total weight of the molecular sieve.

[0046] As used herein, "1,1-diethyl-2,6-dimethylpiperidin-1-ium" refers to a cation having the following structure:

[0047] [ka]

[0048] Method for the preparation of molecular sieves: A method for preparing a molecular sieve is disclosed, comprising forming a synthesis gel comprising an aluminum source, a silicon source, an organic structure directing agent, water, an alkali source, and optionally a seed crystal; and heating the synthesis gel to obtain a molecular sieve, wherein the organic structure directing agent comprises 1,1-diethyl-2,6-dimethylpiperidin-1-ium cations, and the molecular sieve comprises a framework type that is not AEI.

[0049] In some embodiments, the aluminum source is selected from molecular sieve Y (faujasite), a compound of formula Al(OR), aluminum oxide, aluminum hydroxide, and combinations thereof, where R is selected from a C2-C5 alkyl group.

[0050] In some embodiments, the silicon source is selected from molecular sieve Y (faujasite), sodium silicate, colloidal silica, fumed silica, precipitated silica, and combinations thereof.

[0051] In some embodiments, the Si source and the Al source may be the same or different.

[0052] In some embodiments, the organic structure directing agent comprises 1,1-diethyl-2,6-dimethylpiperidin-1-ium hydroxide.

[0053] In some embodiments, the alkaline source comprises at least one element selected from sodium and potassium.

[0054] In some embodiments, the synthesis gel comprises seed crystals, and the seed crystals comprise a CHA framework type.

[0055] In some embodiments, the heating step is carried out at a temperature ranging from 100° C. to 200° C. for a duration ranging from 30 minutes to 100 hours.

[0056] In some embodiments, the synthesis gel has one or more of the following properties: a SiO:AlO ratio in the range of 15-50; a Na:Si ratio in the range of 0.1-1; a ratio of 1,1-diethyl-2,6-dimethylpiperidin-1-ium cations to Si in the range of 0.01-0.3; an OH:Si ratio in the range of 0.1-1; and a HO:Si ratio in the range of 5-50.

[0057] In some embodiments, the synthesis gel has two or more of the following properties: SiO2:Al2O3 ratio in the range of 15-50; Na:Si ratio in the range of 0.1-1; 1,1-diethyl-2,6-dimethylpiperidin-1-ium cation to Si ratio in the range of 0.01-0.3; OH:Si ratio in the range of 0.1-1; and HO:Si ratio in the range of 5-50.

[0058] In some embodiments, the synthesis gel has three or more of the following properties: SiO2:Al2O3 ratio in the range of 15-50; Na:Si ratio in the range of 0.1-1; 1,1-diethyl-2,6-dimethylpiperidin-1-ium cation to Si ratio in the range of 0.01-0.3; OH:Si ratio in the range of 0.1-1; and HO:Si ratio in the range of 5-50.

[0059] In some embodiments, the synthesis gel has four or more of the following properties: SiO2:Al2O3 ratio in the range of 15-50; Na:Si ratio in the range of 0.1-1; 1,1-diethyl-2,6-dimethylpiperidin-1-ium cation to Si ratio in the range of 0.01-0.3; OH:Si ratio in the range of 0.1-1; and HO:Si ratio in the range of 5-50.

[0060] In some embodiments, the synthesis gel has the following properties: SiO:AlO ratio in the range of 15-50; Na:Si ratio in the range of 0.1-1; 1,1-diethyl-2,6-dimethylpiperidin-1-ium cation to Si ratio in the range of 0.01-0.3; OH:Si ratio in the range of 0.1-1; HO:Si ratio in the range of 5-50.

[0061] In some embodiments, the organic structure directing agent comprises a trimethyladamantylammonium cation.

[0062] In some embodiments, the method comprises ion-exchanging a Na-form molecular sieve with an aqueous ammonium salt to form NH + obtaining a molecular sieve of the type NH4 +The method further includes one or more steps selected from the group consisting of a step of calcining the Na-type molecular sieve at a temperature ranging from 200°C to 800°C for a duration ranging from 30 minutes to 12 hours to obtain an H-type molecular sieve, a step of ion-exchanging and / or impregnating the H-type molecular sieve with a transition metal M to obtain an M-type molecular sieve, a step of calcining the M-type molecular sieve at a temperature ranging from 200°C to 800°C for a duration ranging from 30 minutes to 12 hours, a step of treating the Na-type molecular sieve with acid exchange or acid treatment to obtain an H-type molecular sieve, and a step of ion-exchanging the Na-type molecular sieve to obtain an M-type molecular sieve.

[0063] In some embodiments, the method comprises ion-exchanging a Na-form molecular sieve with an aqueous ammonium salt to form NH + obtaining a molecular sieve of the type NH4 + The method further comprises two or more steps selected from the group consisting of a step of calcining the type molecular sieve at a temperature in the range of 200°C to 800°C for a duration in the range of 30 minutes to 12 hours to obtain an H-type molecular sieve, a step of ion-exchanging and / or impregnating the H-type molecular sieve with a transition metal M to obtain an M-type molecular sieve, and a step of calcining the M-type molecular sieve at a temperature in the range of 200°C to 800°C for a duration in the range of 30 minutes to 12 hours.

[0064] In some embodiments, the method comprises ion-exchanging a Na-form molecular sieve with an aqueous ammonium salt to form NH + obtaining a molecular sieve of the type NH4 + The method further includes three or more steps selected from the group consisting of a step of calcining the type molecular sieve at a temperature in the range of 200°C to 800°C for a duration in the range of 30 minutes to 12 hours to obtain an H-type molecular sieve, a step of ion-exchanging and / or impregnating the H-type molecular sieve with a transition metal M to obtain an M-type molecular sieve, and a step of calcining the M-type molecular sieve at a temperature in the range of 200°C to 800°C for a duration in the range of 30 minutes to 12 hours.

[0065] In some embodiments, the method comprises ion-exchanging a Na-form molecular sieve with an aqueous ammonium salt to form NH + obtaining a molecular sieve of the type NH4 + The method further includes the steps of calcining the type molecular sieve at a temperature in the range of 200°C to 800°C for a duration in the range of 30 minutes to 12 hours to obtain an H-type molecular sieve, ion-exchanging and / or impregnating the H-type molecular sieve with a transition metal M to obtain an M-type molecular sieve, and calcining the M-type molecular sieve at a temperature in the range of 200°C to 800°C for a duration in the range of 30 minutes to 12 hours.

[0066] In some embodiments, the transition metal M is selected from iron, copper, and combinations thereof.

[0067] In some embodiments, the synthesis gel is heated to a temperature ranging from 90°C to 200°C for a reaction time ranging from 0.1 hours to 160 hours. In some embodiments, the synthesis gel is heated to a temperature ranging from 120°C to 200°C for a reaction time ranging from 1 hour to 160 hours. In some embodiments, the synthesis gel is heated to a temperature ranging from 140°C to 190°C for a reaction time ranging from 10 hours to 160 hours. In some embodiments, the synthesis gel is heated to a temperature ranging from 140°C to 190°C for a reaction time ranging from 20 hours to 100 hours.

[0068] In some embodiments, the synthesis gel further comprises at least one additional component selected from sodium hydroxide, sulfuric acid, sodium sulfate, and combinations thereof.

[0069] Molecular sieves: A CHA molecular sieve containing 1,1-diethyl-2,6-dimethylpiperidin-1-ium is disclosed.

[0070] Molecular sieves prepared according to the disclosed methods are disclosed.

[0071] In some embodiments, the molecular sieve comprises a CHA framework.

[0072] In some embodiments, the molecular sieve has a crystallinity ranging from 50% to 100%. In some embodiments, the molecular sieve has a crystallinity ranging from 60% to 100%. In some embodiments, the molecular sieve has a crystallinity ranging from 70% to 95%. In some embodiments, the molecular sieve has a crystallinity ranging from 80% to 95%.

[0073] In some embodiments, the molecular sieve comprises a total crystalline phase intensity of 50% to 100% CHA framework type as determined by X-ray diffraction. In some embodiments, the molecular sieve comprises a total crystalline phase intensity of 50% to 98% CHA framework type as determined by X-ray diffraction. In some embodiments, the molecular sieve comprises a total crystalline phase intensity of 50% to 95% CHA framework type as determined by X-ray diffraction. In some embodiments, the molecular sieve comprises a total crystalline phase intensity of 70% to 100% CHA framework type as determined by X-ray diffraction. In some embodiments, the molecular sieve comprises a total crystalline phase intensity of 80% to 98% CHA framework type as determined by X-ray diffraction. In some embodiments, the molecular sieve comprises a total crystalline phase intensity of 80% to 95% CHA framework type as determined by X-ray diffraction.

[0074] In some embodiments, the molecular sieve has an average crystal size in the range of 0.1 μm to 2 μm as measured by scanning electron microscopy.

[0075] In some embodiments, the molecular sieve is a Na-type molecular sieve. In some embodiments, the molecular sieve is a NH4 +It is a molecular sieve. In some embodiments, the molecular sieve is an H-type molecular sieve. In some embodiments, the molecular sieve is an M-type molecular sieve, where M is one or more transition metals. In some embodiments, the molecular sieve is a Cu-type molecular sieve. In some embodiments, the molecular sieve is an Fe-type molecular sieve.

[0076] In some embodiments, the molecular sieve has at least one property selected from a silica to alumina molar ratio in the range of 5 to 50, a molecular sieve surface area in the range of 450 m 2 / g to 650 m 2 / g, and a matrix surface area in the range of 5 m 2 / g to 50 m 2 / g.

[0077] In some embodiments, the molecular sieve has two or more properties selected from a silica to alumina molar ratio in the range of 5 to 50, a molecular sieve surface area in the range of 450 m 2 / g to 650 m 2 / g, and a matrix surface area in the range of 5 m 2 / g to 50 m 2 / g.

[0078] In some embodiments, the molecular sieve has the following properties: a silica to alumina molar ratio in the range of 5 to 50, a molecular sieve surface area in the range of 450 m 2 / g to 650 m 2 / g, and a matrix surface area in the range of 5 m 2 / g to 50 m 2 / g.

[0079] In some embodiments, the molecular sieve has a molecular sieve surface area in the range of 250 m 2 / g to 1000 m 2 / g. In some embodiments, the molecular sieve has a molecular sieve surface area in the range of 400 m 2 / g to 800 m 2In some embodiments, the molecular sieve has a surface area in the range of 500 m 2 / g~600m 2 / g.

[0080] In some embodiments, the molecular sieve is 1 m 2 / g~100m 2 / g. In some embodiments, the molecular sieve has a matrix surface area in the range of 1 m 2 / g~50m 2 / g. In some embodiments, the molecular sieve has a matrix surface area in the range of 1 m 2 / g~40m 2 / g. In some embodiments, the molecular sieve has a matrix surface area in the range of 1 m 2 / g~20m 2 / g. In some embodiments, the molecular sieve has a matrix surface area in the range of 1 m 2 / g~19m 2 In some embodiments, the molecular sieve has a matrix surface area in the range of 5 m 2 / g~19m 2 / g.

[0081] In some embodiments, the molecular sieve has a primary phase crystallinity of greater than 90%. In some embodiments, the molecular sieve has a chabazite crystallinity of greater than 90%. In some embodiments, the molecular sieve has a secondary phase crystallinity of less than 50%. In some embodiments, the molecular sieve has a secondary phase crystallinity of less than 10%. In some embodiments, the molecular sieve has a mordenite crystallinity of less than 50%. In some embodiments, the molecular sieve has a mordenite crystallinity of less than 10%. In some embodiments, the molecular sieve has an amorphous phase of less than 50%. In some embodiments, the molecular sieve has an amorphous phase of less than 10%. In some embodiments, the molecular sieve has a primary phase crystallinity of greater than 50% and a secondary phase crystallinity in the range of 1% to 50%. In some embodiments, the molecular sieve has a primary phase crystallinity greater than 80% and a secondary phase crystallinity ranging from 1% to 20%. In some embodiments, the molecular sieve has a primary phase crystallinity greater than 90% and a secondary phase crystallinity ranging from 1% to 10%. In some embodiments, the molecular sieve has greater than 50% chabazite and 1% to 50% mordenite. In some embodiments, the molecular sieve has greater than 80% chabazite and 1% to 20% mordenite. In some embodiments, the molecular sieve has greater than 90% chabazite and 1% to 10% mordenite. In some embodiments, the molecular sieve has greater than 80% chabazite and 1% to 20% mordenite. In some embodiments, the molecular sieve has greater than 90% chabazite and 0% to 10% mordenite.

[0082] In some embodiments, the molecular sieve is a Cu-type molecular sieve. In some embodiments, the Cu-type molecular sieve contains copper in an amount ranging from 0.1 wt. % to 20 wt. %, calculated as CuO, based on the total weight of the molecular sieve. In some embodiments, the Cu-type molecular sieve contains copper in an amount ranging from 0.1 wt. % to 10 wt. %, calculated as CuO, based on the total weight of the molecular sieve. In some embodiments, the Cu-type molecular sieve contains copper in an amount ranging from 0.1 wt. % to 5 wt. %, calculated as CuO, based on the total weight of the molecular sieve. In some embodiments, the Cu-type molecular sieve contains copper in an amount ranging from 1 wt. % to 5 wt. %, calculated as CuO, based on the total weight of the molecular sieve. In some embodiments, the Cu-type molecular sieve contains copper in an amount ranging from 2 wt. % to 5 wt. %, calculated as CuO, based on the total weight of the molecular sieve.

[0083] In some embodiments, the molecular sieve has less than 20% excess framework aluminum relative to the total aluminum content.

[0084] Catalyst presentation substrate: The molecular sieves of the present disclosure can be deposited on a substrate. The substrate can be any material typically used to prepare catalysts, such as a substrate having a ceramic or metal honeycomb structure. Any suitable substrate can be employed, such as a monolithic substrate having fine parallel gas flow passages extending therethrough from an inlet or outlet face of the substrate (a "honeycomb flow-through substrate") such that the passages are open to fluid flow therethrough. The flow passages, which are essentially straight-line paths from their fluid inlet to their fluid outlet, can be defined by walls on which the molecular sieve is deposited as a washcoat so that gas flowing through the flow passage contacts the molecular sieve. The flow passages in the monolithic substrate can be thin-walled channels, which can have any suitable cross-sectional shape and size, such as trapezoidal, rectangular, square, sinusoidal, hexagonal, elliptical, or circular cross-sections. Such structures can contain 60 to 400 or more gas inlet openings (i.e., cells) per square inch of cross-section.

[0085] The substrate can also be a wall-flow filter substrate, in which the channels are alternately blocked, allowing gas flow to enter the channels from one direction (the inlet direction), flow through the channel walls, and exit the channels from the other direction (the outlet direction). The molecular sieves of the present disclosure can be coated on flow-through or wall-flow filters. When a wall-flow substrate is utilized, the resulting system may be capable of removing particulate matter along with gaseous pollutants such as nitrogen oxides. Wall-flow filter substrates can be made from materials commonly known in the art, such as cordierite, aluminum titanate, or silicon carbide. It will be understood that the loading of molecular sieves on wall-flow substrates depends on substrate properties such as porosity and wall thickness, and is typically lower than that on flow-through substrates.

[0086] The ceramic substrate may be made of any suitable refractory material, such as cordierite, cordierite-alumina, silicon nitride, zircon-mullite, spodumene, alumina-silica-magnesia, zircon silicate, sillimanite, magnesium silicate, zircon, petalite, alpha-alumina, or an aluminosilicate.

[0087] Substrates useful in the molecular sieves of the present disclosure can also be metallic in nature and comprise one or more metals or metal alloys. In some embodiments, metal substrates can be used in various shapes, such as, for example, corrugated sheets or monolithic forms. Suitable metal supports include refractory metals and metal alloys, such as titanium and stainless steel, as well as other alloys in which iron is a substantial or major component. Such alloys may contain one or more of nickel, chromium, and / or aluminum, and the total amount of these metals may advantageously comprise at least 15 wt.% of the alloy, e.g., 10-25 wt.% chromium, 3-8 wt.% aluminum, and up to 20 wt.% nickel. The alloy may also contain minor or trace amounts of one or more other metals, such as manganese, copper, vanadium, and titanium. Surfaces or metal substrates can be oxidized at high temperatures, e.g., 1000°C, to improve corrosion resistance by forming an oxide layer on the substrate surface. High-temperature induced oxidation can improve adhesion of the refractory metal oxide support and catalytically promoting metal components to the substrate.

[0088] Selective catalytic reduction catalyst: A selective catalytic reduction catalyst is disclosed that includes the disclosed molecular sieve disposed on a substrate.

[0089] In some embodiments, the molecular sieve is a Cu-type molecular sieve.

[0090] How to treat exhaust gases: A method for the selective catalytic reduction of nitrogen oxides in an exhaust gas is disclosed, the method comprising contacting the exhaust gas with the selective catalytic reduction catalyst disclosed herein.

[0091] Non-limiting exemplary embodiments: Without limitation, exemplary disclosed embodiments include: 1. A method for preparing a molecular sieve, comprising forming a synthesis gel containing an aluminum source, a silicon source, an organic structure directing agent, water, an alkali source and / or an alkaline earth metal source, and optionally seed crystals; and heating the synthesis gel to obtain a molecular sieve, wherein the organic structure directing agent comprises 1,1-diethyl-2,6-dimethylpiperidin-1-ium cations, and the molecular sieve comprises a framework type that is not AEI. 2. The method of embodiment 1, wherein the aluminum source is selected from zeolites, compounds of formula Al(OR)3, aluminum oxide, aluminum hydroxide, and combinations thereof, and R is selected from C2 to C5 alkyl groups. 3. The method of any one of the preceding claims, wherein the silicon source is selected from zeolites, sodium silicate, colloidal silica, fumed silica, precipitated silica, and combinations thereof. 4. The method of any one of embodiments 1-3, wherein in some embodiments, the organic structure directing agent comprises 1,1-diethyl-2,6-dimethylpiperidin-1-ium hydroxide. 5. The method of any one of embodiments 1 to 4, wherein the synthesis gel comprises an alkalinity source, and the alkalinity source comprises at least one alkali selected from sodium and potassium. 6. The method of any one of embodiments 1 to 5, wherein the heating step is carried out at a temperature ranging from 100°C to 200°C for a duration ranging from 30 minutes to 100 hours. 7. The method of any one of embodiments 1 to 6, wherein the molecular sieve comprises a CHA framework. 8. The method of any one of embodiments 1 to 7, wherein the molecular sieve has a crystallinity in the range of 50% to 100%. 9. The method of any one of embodiments 1 to 8, wherein the molecular sieve comprises 50% to 100% CHA framework type by total crystalline phase intensity as determined by X-ray diffraction. 10. The method of any one of embodiments 1 to 9, wherein the synthesis gel comprises seed crystals, and the seed crystals comprise a CHA framework type. 11. The method of any one of the preceding claims, wherein the synthesis gel has one or more of the following properties: SiO2:Al2O3 ratio in the range of 10 to 50; M:Si ratio in the range of 0.1 to 1; ratio of 1,1-diethyl-2,6-dimethylpiperidin-1-ium cations to Si in the range of 0.01 to 0.3; OH:Si ratio in the range of 0.1 to 1; HO:Si ratio in the range of 5 to 50, wherein M is an alkali metal and / or alkaline earth metal. 12. The method of any one of the preceding embodiments, wherein the molecular sieve has an average crystal size in the range of 0.1 μm to 2 μm as measured by scanning electron microscopy. 13. The method of any one of embodiments 1 to 12, wherein the organic structure directing agent comprises a trimethyladamantylammonium cation. 14. The molecular sieve is a Na-type molecular sieve, and the method involves ion-exchanging the Na-type molecular sieve with an ammonium aqueous solution to obtain NH 4+ obtaining a molecular sieve of the NH 4+ 14. The method of any one of embodiments 1 to 13, further comprising one or more steps selected from the group consisting of calcining the Na-type molecular sieve at a temperature ranging from 200°C to 800°C for a duration ranging from 30 minutes to 12 hours to obtain an H-type molecular sieve, ion-exchanging and / or impregnating the H-type molecular sieve with a transition metal M to obtain an M-type molecular sieve, calcining the M-type molecular sieve at a temperature ranging from 200°C to 800°C for a duration ranging from 30 minutes to 12 hours, treating the Na-type molecular sieve with acid exchange or acid treatment to obtain an H-type molecular sieve, and ion-exchanging the Na-type molecular sieve to obtain an M-type molecular sieve. 15. The method of embodiment 14, wherein the transition metal M is selected from iron, copper, and combinations thereof. 16. A molecular sieve prepared by the method of any one of embodiments 1 to 15. 17. The molecular sieve has a silica to alumina molar ratio in the range of 5 to 50, 450 m2 / g~650m 2 / g and zeolite surface areas in the range of 5m 2 / g~50m 2 17. The molecular sieve of embodiment 16, having at least one property selected from a matrix surface area in the range of 0.1 to 1.0 μm / g. 18. A selective catalytic reduction catalyst comprising a Cu-type molecular sieve prepared according to the method of embodiment 14 or 15. 19. A method for selective catalytic reduction of nitrogen oxides in an exhaust gas, comprising contacting the exhaust gas with the selective catalytic reduction catalyst of embodiment 18. 20. CHA zeolite containing 1,1-diethyl-2,6-dimethylpiperidin-1-ium. 21. The method of any one of embodiments 1-15, wherein the aluminum source is zeolite Y (faujasite). 22. The method of any one of embodiments 1-15, wherein the silicon source is zeolite Y (faujasite).

[0092] Unless indicated to the contrary or otherwise clear from context, a claim or specification condition containing "or" or "and / or" between at least one member of a group is considered satisfied when one, more than one, or all of the group members are present in, employed in, or otherwise relevant to a given product or process. The disclosure includes embodiments in which exactly one group member is present in, employed in, or otherwise relevant to a given product or process. The disclosure includes embodiments in which more than one or all of the group members are present in, employed in, or otherwise relevant to a given product or process.

[0093] Furthermore, the present disclosure encompasses all variations, combinations, and permutations in which at least one limitation, element, clause, or descriptive term from at least one of the enumerated claims is introduced into another claim. For example, any claim dependent on another claim can be amended to include at least one limitation found in any other claim dependent on the same independent claim. When elements are presented as lists, such as in Markush group format, each subgroup of elements is also disclosed, and any element can be removed from the group. In general, when the present disclosure or aspects of the present disclosure are referred to as including particular elements and / or features, it should be understood that embodiments of the present disclosure or aspects of the present disclosure consist of or consist essentially of such elements and / or features. For the sake of brevity, these embodiments have not been specifically described in this language herein. When ranges are given, endpoints are included. Furthermore, unless otherwise indicated or otherwise apparent from the context and the understanding of one of ordinary skill in the art, values ​​expressed as ranges can assume any specific value or subrange within the stated range in different embodiments of the present disclosure, unless the context clearly dictates otherwise.

[0094] Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the disclosure described herein which equivalents are intended to be encompassed by the following claims. [Example]

[0095] The following examples are intended to be illustrative and are not meant to limit the scope of the present disclosure in any way.

[0096] [Table 1]

[0097] The following is an exemplary process by which an exemplary molecular sieve was prepared.

[0098] Procedure for determining percent crystallinity Samples were crushed using a mortar and pestle and then backpacked onto a flat plate mount for analysis. Data were collected in Bragg-Brentano geometry using a PANalytical MPD X'Pert Pro diffraction system. CuKα radiation was used for analysis with generator settings of 45 kV and 40 mA. The optical path consisted of a 1 / 8° divergence slit, a 0.04 rad Soller slit, a 15 mm mask, a 1 / 4° antiscatter slit, a 1 / 8° antiscatter slit, a 0.04 rad Soller slit, a Ni filter, and an X'Celerator linear position-sensitive detector.

[0099] Data were collected from 3° to 70° 2θ using a step size of 0.0167° 2θ and a counting time of 60 seconds per step. Jade Plus 9 analytical X-ray diffraction software was used for phase identification. The phases present were identified by searching / matching the PDF-4 / Full File database from the International Center for Diffraction Data (ICDD). Rietveld refinement was performed using Bruker AXS Topas software to determine the percentage of crystalline phases present.

[0100] Characterization of molecular sieves Pore ​​volume and surface area properties were determined by nitrogen adsorption (BET surface area method). Mesopore and zeolite (micropore) surface areas were determined by N2 adsorption porosimetry on a Micromeritics TriStar 3000 series instrument according to ISO 9277 method.

[0101] Procedure for N2 physical adsorption: Zeolite BET surface area analysis and nitrogen pore size distribution were analyzed on a Micromeritics TriStar 3000 series instrument. Samples were degassed for a total of 6 hours in a Micromeritics SmartPrep degasser (under a dry nitrogen flow, ramped to 300°C for 2 hours, then held at 300°C for 4 hours). Nitrogen BET surface area was determined using five partial pressure points from 0.08 to 0.20. Nitrogen pore size (BJH) was determined using 33 desorption points.

[0102] The surface areas of the zeolite and matrix were determined using the same five partial pressure points and calculated using the t-plot of Harkins and Jura. Pores with diameters greater than 20 Å are considered to contribute to the matrix surface area (MSA).

[0103] Molecular sieve synthesis The molecular sieves were prepared by forming a synthesis gel containing an aluminum source, a silicon source, an organic structure directing agent, water, an alkali source, and optionally seed crystals; and heating the synthesis gel to obtain the molecular sieve. Tables 1 and 2 provide raw material details, gel compositions, and crystallization conditions for the various example materials described. For materials B, G, H, and L, both sodium hydroxide and sodium sulfate are the sodium sources in the synthesis to achieve the specified OH / Si and Na / Si ratios. For material F, potassium hydroxide is the only source of potassium in the synthesis gel.

[0104] [Table 2]

[0105] [Table 3]

[0106] In Table 2, "Am" indicates amorphous and "Un" indicates unknown phase.

[0107] molecular sieve The properties of the produced molecular sieves are listed in Table 2.

[0108] Comparing Material A with Materials C-F, the formation of the CHA phase is observed when 1,1-diethyl-2,6-dimethylpiperidin-1-ium hydroxide (DEDMPOH) is used. In the absence of TMAdaOH, a different zeolite phase (AEI) is synthesized, as can be seen from Materials C and D, regardless of whether a CHA zeolite species is used in these examples. In the absence of DEDMPOH, a small amount of CHA phase is observed in the product of Material E. Materials E and A have different OH / Si ratios, so Material F exhibits a higher OH / Si ratio. - The lack of AEI zeolite formation in Material A indicates that an alternative source of ions (KOH) is not useful for the synthesis of CHA zeolite in this example. + This indicates that the structure-directing role of cations is somewhat modified in the synthesis using both TMAdaOH and DEDMPOH to direct CHA zeolite formation.

[0109] The zeolite synthesized in Material A contained C and N in a ratio of 11.7, indicating the incorporation of both OSDA cations in the product material, reported as the product R1 / R2 ratio in Table 2 and calculated from elemental analysis data.

[0110] Material B describes an alternative route to obtaining CHA zeolite containing both OSDA cations. In this example, the use of CHA species appears to aid in obtaining CHA zeolite as the product, as Material G did not show the formation of CHA zeolite. Interestingly, the product R1 / R2 ratio for Material B (Table 2) is higher than the gel R1 / R2 ratio (Table 1), in contrast to that observed for Material A.

[0111] Figure 1 shows SEM images of materials A, B, H, and I. These materials had similar morphologies when observed by this technique. Figures 6A and 6B show SEM images of material L.

[0112] Although CHA zeolite materials A and B were prepared by synthesis using a zeolitic source of aluminum, it is believed that this same process using a non-zeolitic aluminum source will also produce CHA molecular sieves.

[0113] Selective catalytic reduction catalyst SCR catalysts were prepared using materials A, B, H, and I as follows.

[0114] Ion exchange of Na-type zeolites: All samples were ammonium exchanged to remove the alkali present in the pores and then calcined (450°C for 6 hours) to obtain the respective H-type materials.

[0115] Cu impregnation and catalyst formation: H-type zeolite powder was impregnated with copper(II) nitrate aqueous solution by incipient wetness impregnation and stored in a sealed container at 50°C for 20 h, then dried and calcined at 450°C for 5 h to obtain Cu-loaded zeolite.

[0116] Catalyst Formation: Test samples were prepared by slurrying Cu-loaded zeolite with Zr acetate (5 wt. % ZrO) as a binder and then drying under stirring. This was followed by calcination at 550°C for 1 hour. The resulting product was crushed and then aged at 650°C in a 10% steam / air flow for 50 hours or at 820°C in a 10% steam / air flow for 16 hours (as specified).

[0117] FIG. 7 shows the XRD data for Example L after calcination.

[0118] Selective catalytic reduction of nitrogen oxides SCR measurements were carried out in a fixed bed reactor packed with 120 mg of each test sample together with corundum of the same sieve fraction as diluent to a bed volume of approximately 1 mL according to the following conditions: 1. Gas feed: 500 ppm NO, 500 ppm NH, 5% H, 10% O, and the balance N, gas hourly space velocity (GHSV) 80,000 h -1(for samples aged at 820°C for 16 hours) and 120,000h -1 (for samples aged at 650°C for 50 hours); 2. Temperature: RUN1: 200℃, 400℃, 575℃ (first run for de-greening) 3.RUN2: 175℃, 200℃, 225℃, 250℃, 500℃, 550℃, 575℃.

[0119] The samples aged at 650°C for 50 hours were then subjected to simulated sulfur aging and regeneration as follows. 1. Each catalyst sample was placed downstream of a 2-inch piece of DOC (diesel oxidation catalyst) so that the gas stream first contacted the DOC before reaching the catalyst being evaluated. 2. In this configuration, the catalyst sample was heated to 400°C (ramp rate of 10°C / min) and subjected to a gas flow (8% HO, 7% CO, 10% O and balance N, GHSV 10,000 h -1 ) and maintained at that temperature for 1 hour. 3. Gas supply, GHSV 10,000h -1 At 96 hours, the mixture was switched to 35 ppm SO2, 8% H2O, 7% CO2, 10% O2 and balance N2 (i.e., SO2 was "switched on" in the feed for 96 hours). 4. The SO2 was "switched off" in the gas supply and the sample was allowed to cool to room temperature. 5. For regeneration, the sample was heated to 550 °C (ramp rate of 10 °C / min) and subjected to a gas flow (8% HO, 7% CO, 10% O, and balance N, GHSV 20,000 h). -1 ) and maintained at that temperature for 30 minutes. 6. The samples were then cooled to room temperature and then SCR performance measurements were carried out according to the procedure described above.

[0120] Figure 4 compares the SCR performance of Materials A and H after aging at 650°C for 50 hours at similar Cu / Al ratios. The SCR performance of Cu-loaded Material A is higher than that of Material H over the temperature range measured. xIt can be observed that the conversion rate is significantly higher than that of Material A. Additionally, the amount of the undesired by-product NO produced in the process is lower for Material A at temperatures above 350 °C. Finally, the performance after aging and regeneration (Figure 4C) is significantly higher for Material A compared to Material H, highlighting the superior durability of the catalyst prepared using Material A.

[0121] Figure 5 compares the SCR performance of Material A and Material I after aging at 820 °C for 16 h at similar CuO loadings. The SCR performance of Cu-loaded Material A is higher than that of Material I over the temperature range measured. x It can be observed that the conversion rate is higher than that of Material A. This may be due to the higher hydrothermal stability of Material I, even though Material I has a higher SAR, indicating that CHA zeolite materials of excellent stability and activity can be synthesized using DEDMP as the OSDA. In addition, the amount of the undesirable by-product NO produced in the process is lower for Material A at temperatures below 350°C.

Claims

1. 1. A method for preparing a molecular sieve, comprising: forming a synthesis gel comprising an aluminum source, a silicon source, an organic structure directing agent, water, an alkali source and / or an alkaline earth metal source, and optionally seed crystals; and heating the synthesis gel to obtain the molecular sieve. The method wherein the organic structure directing agent comprises a 1,1-diethyl-2,6-dimethylpiperidin-1-ium cation and the molecular sieve comprises a framework type that is not AEI.

2. (a) the molecular sieve is a small pore zeolite; and / or (b) the aluminum source is a zeolite, of the formula Al(OR) ３ , aluminum oxide, aluminum hydroxide, and combinations thereof; ２ ~C ５ alkyl groups; and / or (c) the silicon source is selected from zeolites, sodium silicate, colloidal silica, fumed silica, precipitated silica, and combinations thereof; and / or 2. The method of claim 1, wherein (d) the organic structure directing agent comprises 1,1-diethyl-2,6-dimethylpiperidin-1-ium hydroxide.

3. 3. The method of claim 1, wherein the molecular sieve has a crystallinity ranging from 50% to 100%.

4. The method according to any one of claims 1 to 3, wherein the synthesis gel comprises the alkalinity source, and the alkalinity source comprises at least one alkali selected from sodium and potassium.

5. 5. A method according to any one of claims 1 to 4, wherein the heating step is carried out at a temperature in the range of from 100°C to 200°C for a duration in the range of from 30 minutes to 100 hours.

6. 6. The method of claim 1, wherein the molecular sieve comprises a CHA framework type and / or the molecular sieve comprises a total crystalline phase intensity of 50% to 100% CHA framework type as determined by X-ray diffraction.

7. The synthesis gel comprises the seed crystals, the seed crystals comprise a CHA framework type, and / or the synthesis gel has the following properties: SiO in the range of 10 to 50 ２ :Al ２ O ３ ratio, an M:Si ratio in the range of 0.1 to 1; a ratio of 1,1-diethyl-2,6-dimethylpiperidin-1-ium cation to Si in the range of 0.01 to 0.3; an OH:Si ratio in the range of 0.1 to 1, and H in the range of 5 to 50 ２ O:Si ratio, 11. The method according to any one of claims 1 to 10, wherein M is an alkali metal and / or alkaline earth metal.

8. 8. The method of any one of claims 1 to 7, wherein the molecular sieve has an average crystal size in the range of 0.1 μm to 2 μm as measured by scanning electron microscopy.

9. The method of any one of claims 1 to 8, wherein the organic structure directing agent comprises a trimethyladamantylammonium cation.

10. the molecular sieve is a Na-type molecular sieve, and the method further comprises: The Na-type molecular sieve is ion-exchanged with an aqueous ammonium solution to obtain NH ４ ＋ obtaining a molecular sieve of the type; Said NH ４ ＋ calcining the H-type molecular sieve at a temperature ranging from 200°C to 800°C for a duration ranging from 30 minutes to 12 hours to obtain H-type molecular sieve; ion-exchanging and / or impregnating the H-type molecular sieve with a transition metal M to obtain an M-type molecular sieve; calcining the M-type molecular sieve at a temperature ranging from 200°C to 800°C for a duration ranging from 30 minutes to 12 hours; treating the Na-type molecular sieve with an acid exchange or acid treatment to obtain the H-type molecular sieve; and and ion-exchanging the Na-type molecular sieve to obtain the M-type molecular sieve.

10. The method of any one of claims 1 to 9, wherein optionally the transition metal M is selected from iron, copper, and combinations thereof.

11. A molecular sieve prepared by the method of any one of claims 1 to 10.

12. The molecular sieve is a silica to alumina molar ratio in the range of 5 to 50; 450m ２ / g~650m ２ / g zeolite surface area, and 5m ２ / g to 50m ２ 12. The molecular sieve of claim 11, having at least one property, optionally at least two properties, selected from a matrix surface area in the range of 0.1 to 1.0 μm / g.

13. A selective catalytic reduction catalyst comprising a Cu-type molecular sieve prepared according to the method of claim 10.

14. 14. A method for selective catalytic reduction of nitrogen oxides in an exhaust gas, comprising contacting the exhaust gas with the selective catalytic reduction catalyst of claim 13.

15. CHA zeolite containing 1,1-diethyl-2,6-dimethylpiperidin-1-ium.

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