Method for producing copper-containing CHA-type zeolite

Abstract

To provide a method of manufacturing copper-containing CHA-type zeolite which does not essentially require a post-treatment process and also has higher yield than a conventional method of crystallization of a copper-containing CHA-type zeolite.SOLUTION: Disclosed is a method of manufacturing a CHA-type zeolite including a step of obtaining a crystallized product by crystallization of a composition containing at least a structure directing agent source including N,N,N-trialkylcyclohexylammonium cations, a polyamine source, a copper source, an alumina source, a silica source, a sodium source, and water, wherein a molar ratio of silica to alumina is 24 or under, a molar ratio of sodium to silica is 0.10 or over and 0.23 or under, and also, a molar ratio of N,N,N-trialkylcyclohexylammonium cation hydroxides to N,N,N-trialkylcyclohexylammonium cations is 0.7 or under.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to a CHA-type zeolite containing copper, and to a CHA-type zeolite crystallized from a composition containing a copper source.

Background Art

[0002] The CHA-type zeolite is an artificially synthesized zeolite reported in Patent Document 1, and a CHA-type zeolite containing copper is widely used as a nitrogen oxide reduction catalyst.

[0003] A method for incorporating copper into a CHA-type zeolite generally involves crystallizing the CHA-type zeolite and then performing post-treatments such as liquid-phase ion exchange or impregnation loading. However, in these methods of incorporation by post-treatment, after incorporating copper into the CHA-type zeolite, a firing step for fixing the copper to the CHA-type zeolite is additionally required. On the other hand, instead of the method of incorporation by post-treatment, a method for producing a CHA-type zeolite that incorporates copper into the CHA-type zeolite during crystallization by using a tetraethylenepentamine copper complex as an organic structure-directing agent has been proposed (Non-Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Non-Patent Documents

[0005]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the method for producing a copper-containing CHA-type zeolite according to Patent Document 1, an additional firing step is required to fix copper to the CHA-type zeolite, resulting in a problem of high production costs.

[0007] In the method for producing a copper-containing CHA-type zeolite proposed in Non-Patent Document 1, the yield of the copper-containing CHA-type zeolite after crystallization is very low.

[0008] An object of the present disclosure is to provide a method for producing a copper-containing CHA-type zeolite that does not require a post-treatment step and has a higher yield than conventional methods for crystallizing a copper-containing CHA-type zeolite.

Means for Solving the Problems

[0009] The present inventors examined a method for producing a copper-containing CHA-type zeolite that does not require a copper-containing step by a post-treatment step in the method for producing a CHA-type zeolite. As a result, it was found that the above problems can be solved under specific crystallization conditions.

[0010] That is, the present invention is as defined in the claims, and the gist of the present disclosure is as follows. [1] A step of crystallizing a composition containing at least a structure-directing agent source containing an N,N,N-trialkylcyclohexylammonium cation, a polyamine source, a copper source, an alumina source, a silica source, a sodium source, and water, wherein the molar ratio of silica to alumina is 24 or less, the molar ratio of sodium to silica is 0.10 or more and 0.23 or less, and the molar ratio of N,N,N-trialkylcyclohexylammonium hydroxide to N,N,N-trialkylcyclohexylammonium cation is 0.7 or less to obtain a crystallized product. A method for producing a CHA-type zeolite having the step. [2] The production method according to [1] above, wherein the composition contains at least amorphous aluminosilicate. [3] The method for producing the product according to [1] or [2] above, wherein the polyamine source is at least one of tetraethylenepentamine and N,N'-bis(3-aminopropyl)ethylenediamine. [4] The method of production according to any one of [1] to [3] above, wherein the N,N,N-trialkylcyclohexylammonium cation is an N,N,N-dimethylethylcyclohexylammonium cation. [5] The manufacturing method according to any one of [1] to [4] above, wherein the copper content of the CHA-type zeolite is greater than 0% by mass and 6.0% by mass or less, and the ratio of the area of ​​the TPR spectrum at 450°C to 800°C to the area of ​​the TPR spectrum at 100°C to 800°C is 0.05 or more and 0.60 or less. [6] A CHA-type zeolite having a copper content greater than 0% by mass and 6.0% by mass or less, and a ratio of the area of ​​the TPR spectrum between 450°C and 800°C to the area of ​​the TPR spectrum between 100°C and 800°C to 0.05 or less to 0.60. [Effects of the Invention]

[0011] This disclosure makes it possible to provide a method for producing copper-containing CHA-type zeolite that does not require a post-processing step and yields a higher yield than conventional methods for crystallizing copper-containing CHA-type zeolite. [Brief explanation of the drawing]

[0012] [Figure 1] This figure shows the TPR spectrum of the CHA-type zeolite from Example 8. [Modes for carrying out the invention]

[0013] The method for producing the CHA-type zeolite described herein will be explained below with reference to an example of an embodiment. The terms used in this embodiment are as follows.

[0014] A "zeolite" is a compound in which the skeletal atoms (hereinafter also referred to as "T atoms") have a regular structure mediated by oxygen (O), and the T atoms consist of at least one of either metallic atoms or metalloid atoms. Examples of metallic atoms include one or more selected from the group consisting of aluminum (Al), iron (Fe), and gallium (Ga). Examples of metalloid atoms include one or more selected from the group consisting of boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), and tellurium (Te).

[0015] A "zeolite-like substance" is a compound in which the T atom has a regular structure mediated by oxygen, and which contains at least one atom other than metals and metalloids (hereinafter also referred to as a "nonmetallic atom") in the T atom. Phosphorus (P) is an example of a nonmetallic atom, and examples of zeolite-like substances include complex phosphorus compounds such as aluminophosphate (AlPO) and silicoaluminophosphate (SAPO).

[0016] In zeolites and zeolite-like materials, the "regular structure of T atoms mediated by oxygen (hereinafter also referred to as the "zeolite structure")" is a skeletal structure identified by the structural code (hereinafter simply referred to as the "structural code") defined by the Structure Commission of the International Zeolite Association. For example, the "CHA structure" is a skeletal structure identified by the structural code "CHA". The zeolite structure can be identified by comparing it with the XRD pattern (hereinafter also referred to as the "reference pattern") of each structure described in Collection of simulated XRD powder patterns for zeolites, Fifth revised edition (2007). In this embodiment, the skeletal structure, crystalline structure, and crystalline phase are used interchangeably.

[0017] "Aluminosilicate" is a composite oxide having a structure consisting of repeating networks of aluminum (Al) and silicon (Si) mediated by oxygen (O). In this embodiment, aluminosilicate also includes forms in which aluminum (Al) and silicon (Si) have a structure consisting of repeating networks mediated by oxygen (O), and in which a portion of the aluminum (for example, 30% or less of the aluminum as T atoms) is substituted with other metal atoms. Among aluminosilicates, those having crystalline XRD peaks in their powder X-ray diffraction (hereinafter also referred to as "XRD") patterns are called "crystalline aluminosilicates," and those not having crystalline XRD peaks are called "amorphous aluminosilicates." In this embodiment, a crystalline XRD peak is an XRD peak with a full width at half maximum (FWHM) of 5° or less.

[0018] In this embodiment, the XRD pattern is measured using CuKα radiation as the source, and the following conditions are used as measurement conditions.

[0019] Acceleration current / voltage: 40mA / 40kV Radiation source: CuKα radiation (λ=1.5405Å) Measurement mode: Continuous scan Scanning conditions: 40° / min Measurement range: 2θ = 3° to 43° Divergence vertical limiting slit: 10mm Divergence / Induction Slit: 1° Light-receiving slit: open Solar light receiving slit: 5° Detector: Semiconductor detector (D / teX Ultra) Filter: Ni filter XRD patterns can be measured using a general powder X-ray diffractometer (e.g., Ultima IV, Rigaku Corporation). Crystalline XRD peaks are peaks whose peak top 2θ is identified and detected during XRD pattern analysis using general analysis software (e.g., SmartLab Studio II, Rigaku Corporation). The following conditions can be used for XRD pattern analysis.

[0020] Fitting conditions: Automatic, background refinement Dispersive pseudo-Voigt function (peak shape) Background removal method: Fitting method Kα2 removal method: Kα1 / Kα2 ratio=0.497 Smoothing method: B-Spline curve Smoothing conditions: Second derivative method, σ cut value = 3, χ threshold = 1.5 The composition in this embodiment, such as the molar ratio of silica to alumina, can be measured by ICP analysis using a general inductively coupled plasma emission spectrometer (e.g., OPTIMA7300DV, manufactured by PERKIN ELMER).

[0021] [Method for manufacturing CHA-type zeolite] The method for producing CHA-type zeolite according to this embodiment is a production method comprising the step of crystallizing a composition containing at least an N,N,N-trialkylcyclohexylammonium cation source, a polyamine source, a copper source, an alumina source, a silica source, a sodium source, and water, wherein the molar ratio of silica to alumina is 24 or less, the molar ratio of sodium to silica is 0.10 or more and 0.23 or less, and the molar ratio of N,N,N-trialkylcyclohexylammonium cation hydroxide to N,N,N-trialkylcyclohexylammonium cation is 0.7 or less to obtain a crystalline product. By doing so, CHA-type zeolite containing copper (hereinafter also referred to as "copper-containing CHA-type zeolite") and further CHA-type zeolite with copper supported (hereinafter also referred to as "copper-supported CHA-type zeolite") can be obtained simultaneously with crystallization.

[0022] Copper inclusion means that the CHA-type zeolite contains copper, while copper support means that the CHA-type zeolite contains copper in a form other than T atoms, that is, a state in which copper does not exist as T atoms, preferably a state in which copper does not exist as T atoms and is contained in at least one of the surface and pores of the zeolite.

[0023] A composition containing at least an N,N,N-trialkylcyclohexylammonium cation, a polyamine source, a copper source, an alumina source, a silica source, a sodium source, and water (hereinafter also referred to as the "raw material composition") is crystallized to obtain a crystalline product (hereinafter also referred to as the "crystallization step"), thereby directly crystallizing a copper-containing CHA-type zeolite that has high resistance to both hot water and catalytic activity.

[0024] The method for producing CHA-type zeolite in this embodiment involves crystallizing a raw material composition containing a copper source, a polyamine source, and a sodium source. Therefore, it is believed that the copper interacts with the polyamine source and the sodium source during crystallization, resulting in the acquisition of CHA-type zeolite containing monovalent and divalent copper.

[0025] The alumina source is at least one of alumina (Al2O3) and its precursors, and examples include one or more selected from the group consisting of alumina, aluminum sulfate, aluminum nitrate, sodium aluminate, aluminum hydroxide, aluminum chloride, amorphous aluminosilicate, metallic aluminum, crystalline aluminosilicate, and aluminum alkoxide. Furthermore, amorphous aluminum compounds, at least one of aluminum hydroxide and amorphous aluminosilicate, and even more preferably amorphous aluminosilicate are used.

[0026] The silica source is at least one of silica (SiO2) and its precursors, and examples include one or more selected from the group consisting of colloidal silica, amorphous silica, sodium silicate, tetraethoxysilane, tetraethyl orthosilicate, precipitated silica, fumed silica, amorphous aluminosilicate, and crystalline aluminosilicate, with amorphous aluminosilicate being preferred.

[0027] The raw material composition preferably includes at least amorphous alumina and silica sources, and more preferably amorphous aluminosilicate. By not including crystalline aluminosilicate as the alumina and silica sources, the raw material composition tends to have lower manufacturing costs and is industrially advantageous. Therefore, the alumina and silica sources are preferably amorphous compounds only, and more preferably amorphous aluminosilicate.

[0028] Sodium sources include sodium-containing salts or compounds. These include one or more selected from the group consisting of sodium chloride, iodide, bromide, hydroxide, and oxide, and more specifically, one or more selected from the group consisting of sodium chloride, bromide, and hydroxide, and more specifically, sodium hydroxide. Sodium contained in other starting materials can also be considered a sodium source. The raw material composition preferably contains at least sodium hydroxide.

[0029] The raw material composition may also contain, in a sufficiently small amount relative to sodium, one or more alkali metals other than sodium, i.e., one selected from the group consisting of potassium, rubidium, and cesium, and furthermore, potassium.

[0030] The structure-directing agent source is at least N,N,N-trialkylcyclohexylammonium cation (TACH + ) contains. TACH + It functions as a structure-directing agent (hereinafter also referred to as "SDA") that directs to the CHA structure. The SDA source is TACH +One or more selected from the group consisting of hydroxides, halides, carbonate monoesters salts, and sulfate monoesters salts; one or more selected from the group consisting of hydroxides, chlorides, bromides, and iodides; one or more selected from the group consisting of hydroxides, bromides, and iodides; at least either hydroxides and bromides, and further bromides can be exemplified.

[0031] TACH contained in the SDA source + is N,N,N-trimethylcyclohexylammonium cation (hereinafter also referred to as "TMCH" + "), N,N,N-dimethylethylcyclohexylammonium cation (hereinafter also referred to as "DMECH" + "), N,N,N-methyldiethylcyclohexylammonium cation (hereinafter also referred to as "MDECH" + "), and N,N,N-triethylcyclohexylammonium cation (hereinafter also referred to as "TECH" + "), one or more selected from the group; at least either DMECH + and MDECH + ; or DMECH + can be mentioned. For crystallizing a copper-containing CHA-type zeolite having the SiO2 / Al2O3 ratio of the present embodiment, the TACH + contained in the SDA source is preferably TACH + other than TMCH + , and at least either DMECH + and MDECH + , and further preferably DMECH + .

[0032] The copper source may be a copper-containing compound, one or more selected from the group consisting of copper sulfate, copper nitrate, copper acetate, copper oxide, and copper hydroxide; further, one or more selected from the group consisting of copper sulfate, copper nitrate, copper acetate, and copper oxide; and further, copper sulfate can be exemplified. Also, copper contained in other starting materials such as a polyamine source can also be regarded as a copper source. The raw material composition preferably contains at least copper sulfate.

[0033] The polyamine source may be any compound containing a polyalkyl polyamine, and may include one or more selected from the group consisting of tetraethylenepentamine (hereinafter also referred to as "TEPA"), N,N'-bis(3-aminopropyl)ethylenediamine (hereinafter also referred to as "EDPTA"), triethylenetetramine, diethylenetriamine, ethylenediamine, diethylenetriamine, and pentaethylenehexamine, or at least one of TEPA and EDPTA. The polyalkyl polyamine may be at least one selected from the group consisting of linear, branched, and cyclic polyamines. The polyamine source may also contain ethyleneamine as an impurity, i.e., it may be a polyalkylamine containing ethyleneamine.

[0034] Preferably, the copper source and the polyamine source in the raw material composition are different compounds, for example, copper sulfate and at least one of TEPA and EDPTA.

[0035] The water contained in the raw material composition may be deionized water, pure water, structural water, water as a solvent, or water (H2O) contained in other starting materials.

[0036] The raw material composition preferably does not contain fluorine (F) or phosphorus (P), and the fluorine and phosphorus content of the raw material composition is below the detection limit, respectively (for example, fluorine content of 1 ppm by mass or less, phosphorus content of 1 ppm by mass or less, or fluorine and phosphorus content of 1 ppm by mass or less).

[0037] The molar ratio of silica to alumina in the raw material composition (SiO2 / Al2O3 ratio) is 24 or less, preferably 22 or less, or 20 or less. The crystallized product obtained in the crystallization process tends to have a lower SiO2 / Al2O3 ratio than the raw material composition. When the SiO2 / Al2O3 ratio of the raw material composition is within these values, a copper-containing CHA-type zeolite with high catalytic activity is obtained when used as a nitrogen oxide reduction catalyst, ranging from a low temperature range of 150°C to a high temperature range of 600°C. Furthermore, the SiO2 / Al2O3 ratio may be 8 or more, 10 or more, 13 or more, or 16 or more.

[0038] To suppress crystallization of zeolites other than CHA-type zeolites, the TACH of the raw material composition is used. + The molar ratio of N,N,N-trialkylcyclohexylammonium hydroxide (hereinafter also referred to as "TACHOH") to (hereinafter referred to as "TACHOH / TACHOH") + Also called the "ratio". The ratio is 0.7 or less, preferably 0.5 or less or 0.4 or less. TACHOH / TACH + The ratio may be 0 (zero) (i.e., the raw material composition may not contain TACHOH), but the raw material composition contains TACHOH, and TACHOH / TACH + The ratio may be greater than 0 or greater than 0.25.

[0039] Preferably, the molar ratio of sodium to silica in the raw material composition is 0.10 or more and 0.23 or less, 0.13 or more or 0.15 or more, and 0.22 or less or 0.21 or less.

[0040] Preferred compositions for the raw material composition include the following molar compositions. In the following, SDA is TACH + And, TACH + DMECH + The SDA / SiO2 ratio in cases such as DMECH +The ratio can be considered as the (K+Cs) / SiO2 ratio, etc. Also, if M is an alkali metal other than sodium, and the raw material composition contains two or more alkali metals other than sodium (for example, potassium and cesium), the M / SiO2 ratio can be considered as the (K+Cs) / SiO2 ratio, etc. Also, TACHOH / TACH + TACH in ratio + This is a TACH that has deviated from TACHOH. + Includes.

[0041] SiO2 / Al2O3 ratio = 8 or higher, 10 or higher, 13 or higher, or 16 or higher, 24 or younger, 22 or younger, or 20 or younger SDA / SiO2 ratio = 0.02 or higher, 0.04 or higher, or 0.08 or higher, 0.5 or less, 0.3 or less, or 0.2 or less TACHOH / TACH + Ratio = 0 or greater, greater than 0, or 0.25 or greater, 0.7 or less, 0.5 or less, or 0.4 or less Polyamine / SiO2 ratio = 0.01 or higher, 0.02 or higher, or 0.03 or higher, 0.5 or less, 0.3 or less, or 0.2 or less Cu / SiO2 ratio = 0.01 or higher, 0.02 or higher, or 0.03 or higher, 0.5 or less, 0.3 or less, or 0.2 or less Na / SiO2 ratio = 0.10 or higher, 0.13 or higher, or 0.15 or higher, 0.23 or less, 0.22 or less, or 0.21 or less M / Na ratio = 0 or greater, 0.001 or greater, or 0.005 or greater, Less than 0.05, 0.03 or less, or 0.01 or less H2O / SiO2 ratio = 3 or more, 5 or more, 10 or more, or 15 or more, 50 or less, 30 or less, or 20 or less To promote the crystallization of CHA-type zeolite, the raw material composition may contain seed crystals in a sufficiently small amount relative to the alumina and silica sources. The seed crystals may be one or more selected from the group consisting of CHA-type zeolite, AFX-type zeolite, ERI-type zeolite, CHA-type zeolite, LEV-type zeolite, and OFF-type zeolite, and CHA-type zeolite is an example. The seed crystals contained in the raw material composition may have a ratio (hereinafter also referred to as "seed crystal content") of the total mass of silicon (Si) and aluminum (Al) of the seed crystals converted to SiO2 and Al2O3, respectively, to the total mass of silicon (Si) and aluminum (Al) of the raw material composition (without seed crystals) converted to SiO2 and Al2O3, respectively, which is greater than 0% by mass, 0.5% by mass or more, or 1% by mass or more, and 10% by mass or less, 5% by mass or less, or 3% by mass or less. The raw material composition may not contain seed crystals, i.e., the seed crystal content may be 0% by mass.

[0042] In the crystallization process, the raw material composition is crystallized. Any method that causes the raw material composition to crystallize is acceptable, and hydrothermal synthesis is a suitable method. The following conditions are examples of conditions for hydrothermal synthesis.

[0043] Crystallization temperature: 130°C or higher, 140°C or higher, 150°C or higher, or 155°C or higher, Below 200℃, below 180℃, or below 170℃ Crystallization time: 1 hour or more, 10 hours or more, or 24 hours or more, 7 days or less, 5 days or less, 3 days or less, or 2 days or less Crystallization state: At least one of the following: stirred state and / or standing state, or stirred state. Crystallization pressure: Autoclavation pressure For example, when crystallizing a copper-containing CHA-type zeolite with an SiO2 / Al2O3 ratio of 24 or less, if the crystallization temperature is 150°C or higher, a single-phase CHA-type zeolite can be crystallized in 3 days or less.

[0044] The manufacturing method of this embodiment can produce copper-containing CHA-type zeolite with a higher yield compared to conventional methods for crystallizing copper-containing CHA-type zeolite.

[0045] The yield is calculated as the total mass W of Al (calculated as Al2O3) and Si (calculated as SiO2) in the raw material composition. Raw The total mass W of Al (calculated as Al2O3) and Si (calculated as SiO2) in the copper-containing CHA-type zeolite obtained by the manufacturing method of this embodiment. Cry The ratio ((W Cry / W Raw This refers to (x 100). The yield of the manufacturing method of this embodiment is 100% or less, more specifically 99% or less, and also 85% or more, 90% or more, and more specifically 95% or more.

[0046] The manufacturing method of this embodiment may include at least one of a washing step, a drying step, an SDA removal step, and an ion exchange step.

[0047] The washing process involves solid-liquid separation of the CHA-type zeolite and the liquid phase. The washing process can be carried out by solid-liquid separation using a known method, and the CHA-type zeolite obtained as the solid phase can be washed with pure water.

[0048] The drying process removes moisture physically adsorbed onto the CHA-type zeolite. The drying conditions are arbitrary, but examples include drying the CHA-type zeolite in air at a temperature between 50°C and 150°C for at least two hours, either by standing or using a spray dryer.

[0049] The SDA removal process removes SDA contained in the CHA-type zeolite. Examples of SDA removal methods include one or more selected from the group consisting of liquid-phase treatment with an acidic aqueous solution, replacement treatment with resin, thermal decomposition treatment, and calcination treatment. From the viewpoint of manufacturing efficiency, it is preferable that the SDA removal process is at least one of thermal decomposition treatment and calcination treatment.

[0050] The ion exchange process involves using a CHA-type zeolite of any desired cation type. For example, the cation type can be ammonium (NH4+ In the case of a ) type, one method is to mix and stir the CHA type zeolite in an aqueous solution of ammonium chloride and perform ion exchange. Alternatively, the cation type can be proton (H + When using the ) type, ammonium (NH4 + One method is to calcine the CHA-type zeolite in the atmosphere.

[0051] The copper content refers to the total mass (W) of Al (calculated as Al2O3), Si (calculated as SiO2), and Cu in the CHA-type zeolite obtained by the manufacturing method of this embodiment. Cry-Cu ) relative to the Cu mass W Cu Ratio [mass %] ((W Cu / W Cry-Cu This refers to () × 100).

[0052] In the manufacturing method of this embodiment, the upper and lower limits of parameters such as the SiO2 / Al2O3 ratio and other compositions, seed crystal content, crystallization temperature, crystallization time, and yield may be any combination as described above.

[0053] [CHA-type zeolite] The CHA-type zeolite of this embodiment is a CHA-type zeolite having a copper content of more than 0% by mass and 6.0% by mass or less, and a ratio of the area of ​​the TPR spectrum between 450°C and 800°C to the area of ​​the TPR spectrum between 100°C and 800°C to 0.05 or more and 0.60 or less. The CHA-type zeolite of this embodiment is a CHA-type zeolite containing copper, and may be considered as a copper-containing CHA-type zeolite.

[0054] The copper content of the CHA-type zeolite in this embodiment is more than 0% by mass, and preferably 2.0% by mass or more. A copper content greater than 0% by mass, i.e., the presence of copper, allows the CHA-type zeolite of this embodiment to be expected to exhibit excellent catalytic activity as an NH3-SCR (Selective Catalytic Reduction) catalyst. Furthermore, the copper content of the CHA-type zeolite in this embodiment is preferably 6.0% by mass or less, 5.0% by mass or less, or 4.0% by mass or less. If the copper content exceeds 6.0% by mass, copper that does not contribute to the NH3-SCR reaction may reduce the catalytic activity.

[0055] The copper content in this embodiment is a value that can be determined in the same way as the copper content in the CHA-type zeolite obtained by the manufacturing method of this embodiment described above.

[0056] The copper contained in the CHA-type zeolite of this embodiment is preferably supported. That is, the copper contained in the CHA-type zeolite of this embodiment is preferably contained as atoms other than T atoms, and more preferably contained on the surface and within the pores of the CHA-type zeolite.

[0057] In this embodiment, the CHA-type zeolite has a ratio (hereinafter also referred to as the "spectral area ratio") of 0.05 to 0.60 of the area of ​​the TPR spectrum between 450°C and 800°C (hereinafter also referred to as the "H-spectral area") to the area of ​​the TPR spectrum between 100°C and 800°C (hereinafter also referred to as the "A-spectral area").

[0058] The area of ​​the TPR spectrum below 450℃ is divalent copper (Cu 2+ ), and the area of ​​the TPR spectrum above 450°C is monovalent copper (Cu +) corresponds to ). Therefore, the spectral area ratio is one indicator of the proportion of monovalent copper in the copper contained in the CHA-type zeolite. The fact that the CHA-type zeolite of this embodiment contains monovalent copper, and furthermore, that monovalent and divalent copper coexist in this ratio, makes it easier to achieve both high reactivity in the NH3-SCR reaction and durability as an NH3-SCR catalyst. The CHA-type zeolite of this embodiment preferably has a spectral area ratio of 0.07 or higher, 0.08 or higher, or 0.15 or higher, and more preferably 0.50 or lower or 0.45 or lower, and more preferably 0.30 or lower.

[0059] In this embodiment, the A-spectral area, H-spectral area, and spectral area ratio can be calculated from the TPR spectrum obtained by hydrogen-temperature-reducing (H2-TPR) measurement under the following conditions.

[0060] Pretreatment: Gas type - Helium Gas flow rate: 50 mL / min Processing temperature: 300℃ Processing time: 0.5 hours H2-TPR: Gas types: Argon, Hydrogen Gas flow rate: Argon: 28.5 mL / min Hydrogen: 1.5 mL / min Heating rate: 10°C / min Measurement temperature 100℃~800℃ H2-TPR can be measured using a general catalyst evaluation instrument (for example, instrument name: BELCATII, manufactured by MicrotracBEL).

[0061] The A-spectral area (mmol / g) and H-spectral area (mmol / g) can be determined from the TPR spectrum obtained by the H2-TPR measurement described above by calculating the integral values ​​of the TPR spectrum between 100°C and 800°C, and the integral values ​​of the TPR spectrum between 450°C and 800°C, per unit mass [g] of copper-containing CHA-type zeolite.

[0062] The CHA-type zeolite used for H2-TPR measurement is a CHA-type zeolite that is substantially SDA-free (described later), and it is preferable that it is a CHA-type zeolite that has undergone heat treatment.

[0063] The molar ratio of silica to alumina (SiO2 / Al2O3 ratio) of the CHA-type zeolite in this embodiment is 8 or more, 10 or more, 13 or more, or 16 or more, and may also be 24 or less, 22 or less, or 20 or less.

[0064] In this embodiment, the molar ratio of copper to alumina in the CHA-type zeolite (hereinafter also referred to as the "Cu / Al2O3 ratio") is greater than 0, 0.20 or more, or 0.40 or more, and may also be 1.00 or less, 0.90 or less, 0.80 or less, or 0.60 or less.

[0065] The CHA-type zeolite of this embodiment may contain SDA, and examples include an SDA / SiO2 ratio of 0 or more, greater than 0, or 0.001 or more, and also 0.15 or less, 0.10 or less, or 0.09 or less. Since the catalytic and adsorbent properties tend to be higher, it is preferable that the CHA-type zeolite of this embodiment is substantially SDA-free, and it is preferable that the SDA / SiO2 ratio is 0.05 or less, 0.02 or less, or 0.01 or less.

[0066] In the CHA-type zeolite of this embodiment, the SiO2 / Al2O3 ratio and other compositional parameters, as well as the upper and lower limits of the spectral area ratio, may be any combination as described above. [Examples]

[0067] The embodiments of this model will be described below with reference to examples. However, the embodiments are not limited to these examples. (Zeolite structure) XRD measurements of the sample were performed using a powder X-ray diffractometer (instrument name: UltimaIV, manufactured by Rigaku Corporation). The measurement conditions were as follows:

[0068] Acceleration current / voltage: 40mA / 40kV Radiation source: CuKα radiation (λ=1.5405Å) Measurement mode: Continuous scan Scanning conditions: 40° / min Measurement range: 2θ = 3° to 43° Divergence vertical limiting slit: 10mm Divergence / Induction Slit: 1° Light-receiving slit: open Solar light receiving slit: 5° Detector: Semiconductor detector (D / teX Ultra) Filter: Ni filter The obtained XRD patterns were analyzed using the analysis software included with the instrument (software name: Smart Lab Studio II, manufactured by Rigaku Corporation) under the following conditions.

[0069] Fitting conditions: Automatic, background refinement Dispersive pseudo-Voigt function (peak shape) Background removal method: Fitting method Kα2 removal method: Kα1 / Kα2 ratio=0.497 Smoothing method: B-Spline curve Smoothing conditions: Second derivative method, σ cut value = 3, χ threshold = 1.5 The zeolite structure was identified by comparing the analyzed XRD pattern with a reference pattern. (composition analysis) The composition of the sample was analyzed using a standard inductively coupled plasma emission spectrometer (instrument name: OPTIMA7300DV, manufactured by PERKIN ELMER). The sample was dissolved in a mixed solution of hydrofluoric acid and nitric acid to prepare the measurement solution. The composition of the sample was then analyzed using the obtained measurement solution. (yield) The yield was calculated using the following formula.

[0070] Yield (mass%) = W Cry / W Raw ×100 W in the above equation Cry and W RawThis was calculated using the mass ratios of Si and Al determined by compositional analysis. (Copper content) The copper content was calculated using the following formula.

[0071] Copper content (mass%) = (W Cu / W Cry-Cu ) × 100 W in the above equation Cry-Cu and W Cu This was calculated using the mass ratios of Si, Al, and Cu determined by compositional analysis.

[0072] (TPR spectrum) H2-TPR measurements were performed using a general catalyst evaluation device (device name: BELCATII, manufactured by MicrotracBEL). The pretreatment and H2-TPR conditions are shown below.

[0073] Sample quantity: 0.2g Pretreatment: Gas type - Helium Gas flow rate: 50 mL / min Processing temperature: 300℃ Processing time: 0.5 hours H2-TPR: Gas types: Argon, Hydrogen Gas flow rate: Argon: 28.5 mL / min Hydrogen: 1.5 mL / min Heating rate: 10°C / min Measurement temperature 100℃~800℃ The H-spectral area and A-spectral area were calculated by dividing the integral values ​​(mmol) of the TPR spectrum between 100°C and 800°C, and the integral values ​​(mmol) of the TPR spectrum between 450°C and 800°C, obtained from the H2-TPR measurement results, by the sample amount (0.2g). From the obtained values, the spectral area ratio was determined.

[0074] Example 1 N,N,N-dimethylethylcyclohexylammonium bromide (hereinafter also referred to as "DMECHBr"), copper sulfate, TEPA, 48% sodium hydroxide aqueous solution, pure water, and amorphous aluminosilicate (SiO2 / Al2O3 ratio = 20.5) were mixed to obtain a raw material composition having the following molar composition.

[0075] SiO2 / Al2O3 ratio =20.5 DMECHBr / SiO2 ratio =0.12 TEPA / SiO2 ratio =0.06 Cu / SiO2 ratio =0.04 Na / SiO2 ratio =0.16 H2O / SiO2 ratio =20 TACHOH / TACH + ratio =0.00 SSZ-13 (CHA-type zeolite) was mixed with the obtained raw material composition so that the seed crystal content was 1.0% by mass. 50 g of this raw material composition was then placed in an 80 mL sealed container, and the container was reacted at 160°C for 72 hours while rotating and stirring at 55 rpm. The resulting crystals were separated into solid and liquid phases, washed with deionized water, and dried overnight in the air at 110°C. The crystals were copper-containing CHA-type zeolite (copper-supported CHA-type zeolite), with an SiO2 / Al2O3 ratio of 20.4, a Cu / Al2O3 ratio of 0.59, a copper content of 2.7% by mass, and an SDA / SiO2 ratio of 0.10. The yield was 99.5%.

[0076] Example 2 Crystallized products were obtained in the same manner as in Example 1, except that N,N,N-dimethylethylcyclohexylammonium hydroxide (hereinafter also referred to as "DMECHOH") was used in addition to DMECHBr, and a raw material composition having the following molar composition was used.

[0077] SiO2 / Al2O3 ratio =20.5 DMECHBr / SiO2 ratio =0.09 DMECHOH / SiO2 ratio =0.03 TEPA / SiO2 ratio =0.06 Cu / SiO2 ratio =0.04 Na / SiO2 ratio =0.16 H2O / SiO2 ratio =20 TACHOH / TACH + ratio =0.25 The crystalline product was a copper-containing CHA-type zeolite (copper-supported CHA-type zeolite), with an SiO2 / Al2O3 ratio of 20.1, a Cu / Al2O3 ratio of 0.72, a copper content of 3.3% by mass, and an SDA / SiO2 ratio of 0.097. The yield was 98.2%.

[0078] Example 3 Crystallized products were obtained in the same manner as in Example 1, except that DMECHBr, copper sulfate, EDPTA, a 48% aqueous sodium hydroxide solution, pure water, and amorphous aluminosilicate (SiO2 / Al2O3 ratio = 17.8) were used, and the raw material composition having the following molar composition was used.

[0079] SiO2 / Al2O3 ratio =17.8 DMECHBr / SiO2 ratio =0.12 EDPTA / SiO2 ratio =0.06 Cu / SiO2 ratio =0.04 Na / SiO2 ratio =0.20 H2O / SiO2 ratio =18 TACHOH / TACH + ratio =0.00 The crystalline product was a copper-containing CHA-type zeolite (copper-supported CHA-type zeolite), with an SiO2 / Al2O3 ratio of 17.6, a Cu / Al2O3 ratio of 0.51, a copper content of 2.8% by mass, and an SDA / SiO2 ratio of 0.080. The yield was 98.9%.

[0080] Example 4 Crystallized products were obtained in the same manner as in Example 1, except that amorphous aluminosilicate (SiO2 / Al2O3 ratio = 20.1) was used and a raw material composition having the following molar composition was used.

[0081] SiO2 / Al2O3 ratio =20.1 DMECHOH / SiO2 ratio =0.03 DMECHBr / SiO2 ratio =0.12 Na / SiO2 ratio =0.16 H2O / SiO2 ratio =18 TACHOH / TACH + ratio =0.00 The crystalline product was a copper-containing CHA-type zeolite (copper-supported CHA-type zeolite), with an SiO2 / Al2O3 ratio of 19.8, a Cu / Al2O3 ratio of 0.59, a copper content of 2.8% by mass, and an SDA / SiO2 ratio of 0.098. The yield was 98.4%.

[0082] Examples 5 to 8 The copper-containing CHA-type zeolites obtained in Examples 1 to 4 were calcined in air at 600°C for 4 hours to obtain the calcined copper-containing CHA-type zeolites, which were then designated as the copper-containing CHA-type zeolites of Examples 5 to 8. The SDA / SiO2 ratios were 0.006 (Example 5), 0.005 (Example 6), 0.010 (Example 7), and 0.006 (Example 8), respectively, while the SiO2 / Al2O3 ratio, Cu / Al2O3 ratio, and copper content were the same as before calcination.

[0083] Comparative Example 1 Crystallized products were obtained in the same manner as in Example 2, except that a raw material composition having the following molar composition was used.

[0084] SiO2 / Al2O3 ratio =20.5 DMECHBr / SiO2 ratio =0.03 DMECHOH / SiO2 ratio =0.09 TEPA / SiO2 ratio =0.06 Cu / SiO2 ratio =0.04 Na / SiO2 ratio =0.16 H2O / SiO2 ratio =20 TACHOH / TACH + ratio =0.75 The resulting crystallized material was a MOR-type zeolite.

[0085] Comparative Example 2 Crystallization was carried out in the same manner as in Example 1, except that DMECHBr was not used and a raw material composition having the following molar composition was used.

[0086] SiO2 / Al2O3 ratio =20.5 TEPA / SiO2 ratio =0.06 Cu / SiO2 ratio =0.04 Na / SiO2 ratio =0.16 H2O / SiO2 ratio =20 In this comparative example, the raw material composition did not crystallize, and the product was amorphous.

[0087] From Comparative Example 1, TACHOH / TACH + It was confirmed that when a raw material composition with a high ratio was used, MOR-type zeolite crystallized, and CHA-type zeolite could not be obtained. Furthermore, from Comparative Example 1, it was confirmed that CHA-type zeolite did not crystallize even when DMECH salt was not used as SDA.

[0088] Comparative Example 3 Crystallization was carried out in the same manner as in Example 1, except that the composition ratio of the raw material composition was changed to obtain a raw material composition having the following molar composition.

[0089] SiO2 / Al2O3 ratio =20.5 DMECHBr / SiO2 ratio =0.12 TEPA / SiO2 ratio =0.06 Cu / SiO2 ratio =0.04 Na / SiO2 ratio =0.08 H2O / SiO2 ratio =20 TACHOH / TACH + ratio =0.00 In this comparative example, the Na / SiO2 ratio was less than 0.10, so the raw material composition did not crystallize, and the product was amorphous.

[0090] Comparative Example 4 Crystallized products were obtained in the same manner as in Example 1, except that a raw material composition having the following molar composition was used.

[0091] SiO2 / Al2O3 ratio =20.5 DMECHBr / SiO2 ratio =0.12 TEPA / SiO2 ratio =0.06 Cu / SiO2 ratio =0.04 Na / SiO2 ratio =0.24 H2O / SiO2 ratio =20 TACHOH / TACH + ratio =0.00 The resulting crystallized material was a MOR-type zeolite.

[0092] From here on, DMECH + It was confirmed that even with raw material compositions containing [specific components], if the Na / SiO2 ratio exceeds the range of the CHA manufacturing method, the copper-containing CHA-type zeolite will not crystallize.

[0093] Comparative Example 5 Based on the preferred synthesis range described in Table 1 of Japanese Patent No. 6791758, a CHA-type zeolite was produced. Specifically, a raw material composition having the following molar composition was obtained by mixing TMAdAOH, copper sulfate, TEPA, fumed silica, and aluminum hydroxide.

[0094] SiO2 / Al2O3 ratio =34.0 TMAdAOH / SiO2 ratio =0.50 TEPA / SiO2 ratio =0.03 Cu / SiO2 ratio =0.03 Na / SiO2 ratio =0.00 H2O / SiO2 ratio =20 SSZ-13 (CHA-type zeolite) was mixed with the obtained raw material composition so that the seed crystal content was 1.0% by mass. 50 g of this raw material composition was then placed in an 800 mL sealed container, and the container was reacted at 145°C for 144 hours while rotating and stirring at 55 rpm. The resulting crystals were separated into solid and liquid phases, washed with deionized water, and dried overnight in the air at 110°C. The crystals were copper-containing CHA-type zeolite with an SiO2 / Al2O3 ratio of 29.4, a Cu / Al2O3 ratio of 1.13, a copper content of 3.7% by mass, and an SDA / SiO2 ratio of 0.008. The yield was 86.5%.

[0095] The obtained CHA-type zeolite was calcined in air at 600°C for 4 hours to obtain copper-containing CHA-type zeolite, which was used as the zeolite for this comparative example.

[0096] The copper-containing CHA-type zeolites obtained in Examples 5 to 8 and Comparative Example 5 were pretreated, and H2-TPR measurements were performed. The results of the H2-TPR measurements are shown in the table below. The TPR spectrum of the copper-containing CHA-type zeolite from Example 8 is shown in Figure 1.

[0097] [Table 1] The H2-TPR results showed that Examples 5 to 8 had a spectral area ratio of 0.05 to 0.60, while Comparative Example 5 had a spectral area ratio of 0.

Claims

1. A method for producing a CHA-type zeolite, comprising the step of crystallizing a composition comprising a structure-directing agent source containing at least N,N,N-trialkylcyclohexylammonium cation, a polyamine source, a copper source, an alumina source, a silica source, a sodium source, and water, wherein the molar ratio of silica to alumina is 24 or less, the molar ratio of sodium to silica is 0.10 or more and 0.23 or less, and the molar ratio of N,N,N-trialkylcyclohexylammonium cation hydroxide to N,N,N-trialkylcyclohexylammonium cation is 0.7 or less, to obtain a crystalline product.

2. The manufacturing method according to claim 1, wherein the composition comprises at least an amorphous aluminosilicate.

3. The method for producing an ingredient according to claim 1 or 2, wherein the polyamine source is at least one of tetraethylenepentamine and N,N'-bis(3-aminopropyl)ethylenediamine.

4. The production method according to claim 1 or 2, wherein the N,N,N-trialkylcyclohexylammonium cation is an N,N,N-dimethylethylcyclohexylammonium cation.

5. The manufacturing method according to claim 1 or 2, wherein the copper content of the CHA-type zeolite is greater than 0% by mass and 6.0% by mass or less, and the ratio of the area of ​​the TPR spectrum at 450°C to 800°C to the area of ​​the TPR spectrum at 100°C to 800°C is 0.05 or more and 0.60 or less.

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