Method for manufacturing copper-supported zeolite

Abstract

The objective is to provide a novel technology related to the manufacturing method of copper-supported zeolite. [Solution] A method for producing copper-supported zeolite, comprising the step of mixing a zeolite slurry containing a zeolite whose cation type is at least proton and water with one or more copper sources selected from the group consisting of copper oxide, cuprous oxide and copper hydroxide, wherein the pH of the zeolite slurry is 2.3 or less.

Description

[Technical Field]

[0001] This disclosure relates to a method for producing copper-supported zeolite. [Background technology]

[0002] Zeolites supporting metal ions (hereinafter also referred to as "metal-supported zeolites") are used in a variety of applications, and among them, zeolites supporting copper ions as the metal ions (hereinafter also referred to as "copper-supported zeolites") are widely used as nitrogen oxide reduction catalysts (Patent Document 1) and hydrocarbon adsorbents (Patent Document 2).

[0003] Generally, copper-supported zeolites are manufactured by contacting zeolite without copper ions with a copper compound and then calcining the mixture. For example, Patent Document 1 describes a method of producing copper-supported zeolite by mixing CHA-type zeolite with an aqueous copper sulfate solution and nitric acid, performing an ion exchange reaction, and then calcining the CHA-type zeolite filtered from the mixture. Patent Document 2 describes a method of producing copper-supported CHA-type zeolite by an impregnation loading method, in which CHA-type zeolite is mixed with a small amount of aqueous copper nitrate solution and then calcined. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Special Publication No. 2010-519038 [Patent Document 2] Japanese Patent Publication No. 2019-150822 [Overview of the project] [Problems that the invention aims to solve]

[0005] Patent documents 1 and 2 state that various copper compounds can be used as copper compounds to be brought into contact with zeolite, but the only copper compounds specifically used are copper salts with high solubility in water, such as sulfates or nitrates (hereinafter also referred to as "water-soluble copper salts"), and there is no disclosure or suggestion as to how to use copper salts with low solubility in water.

[0006] Furthermore, in the manufacturing methods described in Patent Documents 1 and 2, copper-supported zeolite is produced by contacting a copper salt aqueous solution containing a dissolved water-soluble copper salt with zeolite and then calcining it. However, when zeolite that has been in contact with a copper salt aqueous solution is calcined, the anions of the water-soluble copper salt (for example, sulfate ions (SO4)) are released. 2- ) and nitrate ions (NO3 - This can result in the generation of exhaust gases that require treatment.

[0007] This disclosure aims to provide a novel technology relating to a method for producing copper-supported zeolite. [Means for solving the problem]

[0008] In this disclosure, we investigated a process for supporting copper ions on zeolite in order to produce copper-supported zeolite. As a result, we found that copper-supported zeolite can be produced without calcination by mixing a zeolite slurry with a pH of 2.3 or lower with a specific copper compound.

[0009] In other words, the present invention is as described in the claims, and the gist of this disclosure is as follows: [1] A method for producing copper-supported zeolite, comprising the step of mixing a zeolite slurry containing a zeolite whose cation type is at least proton and water with one or more copper sources selected from the group consisting of copper oxide, cuprous oxide and copper hydroxide, wherein the pH of the zeolite slurry is 2.3 or less. [2] The method for producing copper-supported zeolite according to [1], wherein the SiO2 / Al2O3 molar ratio of the zeolite is 10 or more and less than 80. [3] A method for producing a copper-supported zeolite according to [1] or [2], wherein the zeolite has at least one skeletal structure selected from the group consisting of AEI, AFX, CHA, CON, DDR, ERI, EUO, FAU, FER, GIS, GME, KFI, LEV, LTA, LTL, MEL, MFI, MOR, MRE, MTN, MTW, MWW, OFF, PHI, RHO, STW, TON, and YFI. [4] A method for producing the copper-supported zeolite according to [3], wherein the zeolite has a CHA skeletal structure. [5] A method for producing copper-supported zeolite according to any one of [1] to [4], wherein the zeolite slurry further comprises one or more selected from the group consisting of sulfuric acid, nitric acid, hydrochloric acid, lactic acid, and formic acid. [6] A method for producing a copper-supported zeolite according to any one of [1] to [5] above, wherein the copper source is copper oxide. [7] The method for producing copper-supported zeolite according to any one of [1] to [6], wherein the zeolite slurry has a solid content concentration of 15% by mass or more and 90% by mass or less, determined from the following formula (1). Solid content concentration = Zeolite mass Wz / (Zeolite mass Wz + Water mass Ww) × 100 ... (1) In equation (1) above, the zeolite mass Wz represents the dry mass [g] of the zeolite contained in the zeolite slurry when heated in air at 600°C for 1 hour, and the water mass Ww represents the mass [g] of water contained in the zeolite slurry. [Effects of the Invention]

[0010] This disclosure provides a novel technology related to a method for producing copper-supported zeolite. [Modes for carrying out the invention]

[0011] The following describes a method for producing copper-supported zeolite, illustrating it with an example of an embodiment. The terms used in this embodiment are as follows:

[0012] 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), titanium (Ti), iron (Fe), zinc (Zn), gallium (Ga), and tin (Sn). 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).

[0013] 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 a metal or metalloid in the T atom. Examples of zeolite-like substances include aluminophosphate (AlPO) and silicoaluminophosphate (SAPO), which are complex phosphorus compounds containing phosphorus (P) as the T atom. In this embodiment, for convenience, a "zeolite-like substance" is distinguished from a "zeolite" in which the T atom consists of at least one of a metal atom and a metalloid atom.

[0014] The "regular structure" in zeolites and zeolite-like materials refers to zeolites that have a skeletal structure specified by the structural code (hereinafter also simply referred to as the "structural code") established by the Structure Commission of the International Zeolite Association (hereinafter also referred to as the "IZA"). For example, "CHA-type zeolite" is a zeolite that has a skeletal structure specified by the structural code "CHA". The skeletal structure of each zeolite can be identified by comparison with the XRD pattern (hereinafter also referred to as the "reference pattern") of each zeolite structure described in, for example, Collection of simulated XRD powder patterns for zeolites, Fifth revised edition (2007). Note that, with respect to the skeletal structure of zeolites, the terms skeletal structure, crystalline structure, and crystalline phase are used synonymously.

[0015] In this embodiment, the XRD pattern can be obtained from XRD measurement under the following conditions. The XRD pattern can be measured using a general powder X-ray diffractometer (for example, the device name: UltimaIV Protectus, manufactured by Rigaku Corporation). Accelerating current and voltage: 40 mA · 40 kV X-ray source: CuKα ray (λ = 1.5405 Å) Measurement mode: Continuous scan Scan condition: 40° / min Measurement range: 2θ = 3° to 43° Divergence vertical limiting slit: 10 mm Divergence / incidence slit: 1° Receiving slit: open Receiving solar slit: 5° Detector: Semiconductor detector (D / teX Ultra2) Filter: Ni filter

[0016] "Aluminosilicate" is a composite oxide having a structure composed of a network of aluminum (Al) and silicon (Si) via oxygen (O). Among aluminosilicates, those having crystalline XRD peaks in their XRD patterns are "crystalline aluminosilicates", and those not having crystalline XRD peaks are "amorphous aluminosilicates". Zeolites in which T atoms consist essentially of aluminum (Al) and silicon (Si) correspond to crystalline aluminosilicates. Here, the statement that T atoms consist essentially of aluminum (Al) and silicon (Si) means not only that T atoms consist only of aluminum (Al) and silicon (Si), but also that T atoms other than aluminum (Al) and silicon (Si) are allowed within the scope of the effects of the present invention.

[0017] The crystal structure of zeolites can be determined by analyzing the XRD pattern using general analysis software (e.g., SmartLab Studio II, manufactured by Rigaku). The following conditions can be used for XRD pattern analysis. Note that crystalline XRD peaks are peaks whose peak top 2θ is identified and detected in the XRD pattern analysis. An example of a crystalline XRD peak with a full width at half maximum (FMAX) of 2θ = 0.50° or less is used. 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

[0018] A "copper-supported zeolite" is a zeolite on which copper ions are supported. Among "copper-supported zeolites," a "copper-supported CHA-type zeolite" is one in which the zeolite supporting the copper ions is a CHA-type zeolite. Here, copper ion support means that the copper ions are contained in the zeolite in a state other than as T atoms. A state in which copper ions are supported can be described as a state in which the copper ions do not exist as T atoms of the zeolite and are contained in at least one of the surface and pores of the zeolite, and it is preferable that they are contained as counterions (hereinafter simply referred to as "counterions") to compensate for the charge of the skeletal structure.

[0019] The "copper content" is the mass percentage of copper in the copper-supported zeolite and can be calculated from the following formula (2). In the following formula (2), the SiO2 content represents the silicon content [mass %] in silica (SiO2) equivalent contained in the copper-supported zeolite, the Al2O3 content represents the aluminum content [mass %] in alumina (Al2O3) equivalent contained in the copper-supported zeolite, and the Cu content represents the copper (Cu) content [mass %] contained in the copper-supported zeolite. Copper content [mass%] = Cu content / (SiO2 content + Al2O3 content + Cu content) × 100 ... (2)

[0020] The composition of copper-supported zeolite (contents of silicon, aluminum, copper, and alkali metals) can be determined by inductively coupled plasma atomic emission spectroscopy (ICP-AES) using a general inductively coupled plasma atomic emission spectrometer (ICP instrument) (for example, instrument name: OPTIMA5300DV, manufactured by PerkinElmer). For compositional analysis, a sample solution obtained by dissolving the copper-supported zeolite in a mixed aqueous solution of hydrofluoric acid and nitric acid can be used.

[0021] The "copper oxide content" is an index that indicates the proportion of copper oxide (hereinafter also referred to as "copper oxide") among the copper contained in the copper-supported zeolite, and can be calculated from the following formula (3). The lower the value of the "copper oxide content," the lower the proportion of copper oxide, and if the value is 0.5% or less, it can be considered that virtually no copper oxide is supported. In the following formula (3), the area intensity ratio Si represents the ratio [-] of the area intensity of the XRD peaks caused by copper oxide normalized by the area intensity of the XRD peaks caused by zeolite in the copper-supported zeolite, and the area intensity ratio Ri represents the ratio [-] of the area intensity of the XRD peaks caused by copper oxide normalized by the area intensity of the XRD peaks caused by zeolite in a sample (hereinafter also referred to as the "reference sample") in which it is assumed that all the copper contained in the copper-supported zeolite is copper oxide. Copper oxide content [%]=area intensity ratio Si / area intensity ratio Ri×100... (3)

[0022] The area intensity ratio Si in equation (3) above can be determined from equation (3a) below. In equation (3a) below, area intensity Sc represents the area intensity [cps°] of the XRD peak caused by copper oxide in copper-supported zeolite, and area intensity Sz represents the area intensity [cps°] of the XRD peak caused by zeolite in copper-supported zeolite. Area intensity ratio Si[%]=area intensity Sc / area intensity Sz×100 (3a)

[0023] The area intensity ratio Ri in equation (3) above can be determined from equation (3b) below. In equation (3b) below, the area intensity Rc represents the area intensity [cps°] of the XRD peak caused by copper oxide in the reference sample, and the area intensity Rz represents the area intensity [cps°] of the XRD peak caused by zeolite in the reference sample. Area intensity ratio Ri[%]=area intensity Rc / area intensity Rz×100 (3b)

[0024] Here, to determine the area intensity ratio Ri in equation (3) above, a reference sample can be prepared by mixing an amount of copper oxide equal to the copper content of the copper-supported zeolite with the zeolite before copper is supported on it, and using this mixture as the reference sample. Copper oxide can be used as the copper oxide mixed as the reference sample.

[0025] Furthermore, to determine the area intensity ratios Si and Ri in equation (3) above, the area intensity of the XRD peaks caused by copper oxide (area intensity Sc in equation (3a) and area intensity Rc in equation (3b) above) can be obtained by separating XRD peaks with peak tops in the range of 2θ = 38.0° to 39.0° from the XRD pattern and using the sum of the area intensities of the separated XRD peaks. To determine the area intensity ratios Si and Ri in equation (3) above, the area intensity of the XRD peaks caused by zeolite (area intensity Sz in equation (3a) and area intensity Rz in equation (3b) above) can be obtained by separating XRD peaks with peak tops in the range of 2θ = 20.0° to 21.0° from the XRD pattern and using the sum of the area intensities of the separated XRD peaks. Note that the sum of the area intensities of the XRD peaks means the sum of the area intensities of the two or more XRD peaks that are separated, if two or more XRD peaks with peak tops within a predetermined diffraction angle (2θ) range are separated, and the sum of the area intensities of the single separated XRD peak if only one XRD peak with a peak top within a predetermined diffraction angle (2θ) is separated.

[0026] To separate XRD peaks from an XRD pattern, you can use general analysis software (for example, SmartLab Studio II, manufactured by Rigaku Corporation), and the following conditions should be used for the analysis. 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: Peak-top method, σ cut-off value = 3, χ threshold = 1.5

[0027] "Copper oxides" is a general term for copper oxide and cuprous oxide. Furthermore, "copper oxide" refers to CuO, and "cuprous oxide" refers to Cu2O.

[0028] "Zeolite slurry" is a mixture containing at least zeolite and water. In this embodiment, "zeolite slurry" only needs to contain at least zeolite and water, and is not limited to the amount of water it contains.

[0029] The method for producing copper-supported zeolite according to this embodiment (hereinafter also referred to as "the manufacturing method of this embodiment") will be described below. This disclosure includes any combination of each configuration and parameter disclosed herein, and the upper and lower limits of the values ​​disclosed herein also include any combination.

[0030] The manufacturing method of this embodiment includes a step of mixing a zeolite slurry containing a zeolite whose cation type is at least proton and water with one or more copper sources selected from the group consisting of copper oxide, cuprous oxide, and copper hydroxide (hereinafter also referred to as the "mixing step"), wherein the pH of the zeolite slurry is 2.3 or less. According to the manufacturing method of this embodiment, which has these characteristics, copper ions can be supported on the zeolite, and copper-supported zeolite can be produced without calcination.

[0031] The zeolite slurry used in the mixing process contains zeolites whose cation type is proton. Zeolites whose cation type is proton have a counterion that is proton (H + Although the zeolite is of the proton type, not all counterions need to be protons; some counterions may be cations other than protons. For example, a zeolite with a proton cation type may contain alkali metal ions as counterions in amounts such that the alkali metal molar ratio to aluminum is 0.3 or less, 0.2 or less, 0.1 or less, 0.05 or less, 0.02 or less, 0.01 or less, or 0.005 or less. From the viewpoint of making it easier for copper ions to be supported on the zeolite, it is preferable that a zeolite with a proton cation type substantially does not contain alkali metals. Note that substantially not containing a specified component means that the specified component is below the detection limit.

[0032] The zeolite contained in the zeolite slurry only needs to have a proton cation type, and its skeletal structure is not limited. However, from the viewpoint of making it easier for copper ions to be supported on the zeolite, it is preferable that it has at least one skeletal structure selected from the group of AEI, AFX, CHA, CON, DDR, ERI, EUO, FAU, FER, GIS, GME, KFI, LEV, LTA, LTL, MEL, MFI, MOR, MRE, MTN, MTW, MWW, OFF, PHI, RHO, STW, TON, and YFI, and it is more preferable that it has the CHA skeletal structure. Note that a zeolite having two or more (two or more types) skeletal structures is a intercrystalline body containing each skeletal structure in any proportion. Furthermore, the zeolite slurry may contain two or more types of zeolites with different skeletal structures (zeolites with a proton cation type).

[0033] The zeolite contained in the zeolite slurry only needs to have a proton cation type, and is not limited to the type of T atom. However, from the viewpoint of durability and economic efficiency, it is preferable that the T atom contains aluminum (Al) and silicon (Si), and it is more preferable that the T atom is substantially composed of aluminum (Al) and silicon (Si), that is, crystalline aluminosilicate.

[0034] The zeolite contained in the zeolite slurry only needs to have a proton cation type, and is not limited to the molar ratio of silicon in silica equivalent to aluminum in alumina equivalent (hereinafter also referred to as the "SiO2 / Al2O3 molar ratio"). However, in order to facilitate application as a nitrogen oxide reduction catalyst or hydrocarbon adsorbent, the SiO2 / Al2O3 molar ratio is preferably 5 or more, 10 or more, 13 or more, or 15 or more, and preferably 40 or less, 30 or less, or 25 or less. The combination of the upper and lower limits of the SiO2 / Al2O3 molar ratio is arbitrary, but in order to facilitate application as a nitrogen oxide reduction catalyst or hydrocarbon adsorbent, the SiO2 / Al2O3 molar ratio of the zeolite contained in the zeolite slurry is preferably 5 or more and 30 or less, more preferably 10 or more and 25 or less, and even more preferably 13 or more and 25 or less.

[0035] The zeolite contained in the zeolite slurry may be commercially available zeolite or synthesized zeolite. The synthesis of the zeolite may be carried out using conventionally known synthesis methods and is not particularly limited; for example, a crystallization step may be used to crystallize a raw material composition containing an alumina source, a silica source, an alkali source, a structure-directing agent source, and water, and the crystallized product (zeolite) obtained by crystallizing the raw material composition and ammonium (NH4) + A synthesis method can be used that includes an ammonium treatment step of contacting the crystalline product (zeolite) that has been in contact with the ammonium-containing solution (hereinafter also referred to as "ammonium-containing solution"), and a calcination step of calcining the crystalline product (zeolite) that has been in contact with the ammonium-containing solution.

[0036] The raw material composition to be crystallized in the crystallization process includes an alumina source. 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 chloride, aluminum hydroxide, amorphous aluminosilicate, metallic aluminum, crystalline aluminosilicate, and aluminum alkoxide. Preferably, one or more selected from the group consisting of aluminum hydroxide, crystalline aluminosilicate, and amorphous aluminosilicate is preferred, and amorphous aluminosilicate is more preferred.

[0037] The raw material composition to be crystallized in the crystallization process includes a silica source. The silica source included in the raw material composition is at least one of silica (SiO2) or 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 at least one of crystalline aluminosilicate and amorphous aluminosilicate being preferred, and amorphous aluminosilicate being more preferred.

[0038] Furthermore, if other starting materials in the raw material composition besides the alumina source contain aluminum, these can be considered as an alumina source. For example, if the silica source is a substance containing aluminum, such as crystalline aluminosilicate or amorphous aluminosilicate, then this silica source can be considered both a silica source and an alumina source.

[0039] The raw material composition crystallized in the crystallization process includes an alkali source. The alkali source can be any compound containing an alkali metal element, for example, at least one of alkali metal hydroxides and halides. The alkali metal element contained in the alkali source is preferably one or more selected from the group consisting of lithium, sodium, potassium, rubidium, and cesium, and more preferably at least one of sodium and potassium.

[0040] The raw material composition crystallized in the crystallization process includes a structure-directing agent (hereinafter also referred to as "SDA") source. The SDA source can be any substance containing SDA, and examples include at least one of SDA and / or a salt of SDA. The SDA included in the SDA source can be a known SDA that directs the skeletal structure of the zeolite to be produced, and can be appropriately set according to the skeletal structure of the zeolite to be produced. For example, one or more SDAs that direct CHA-type zeolite can be selected from the group consisting of N,N,N-dimethylethylcyclohexylammonium (hereinafter also referred to as "DMECHA") cation, (1-adamantyl)trimethylammonium cation, cyclohexylethylammonium cation, N-methyl-3-quinuclidinol cation, trimethylbenzylammonium cation, tetraethylammonium cation, and N,N,N-trimethylexoaminonorbornene cation. Furthermore, examples of salts of SDA include one or more salt forms selected from chloride, bromide, iodide, and hydroxide of SDA, with bromide and hydroxide being preferred.

[0041] The raw material composition that crystallizes in the crystallization process contains water. The water in the raw material composition may be one or more selected from the group consisting of distilled water, deionized water, and pure water. The water in the raw material composition may also originate from other starting materials contained in the raw material composition, such as solvents or aqueous compounds.

[0042] The composition of the raw material composition to be crystallized in the crystallization process can be adjusted as appropriate to produce zeolite of the desired composition, but examples include the following molar compositions. In the following molar compositions, the SDA / SiO2 molar ratio indicates the molar ratio of SDA to silicon in silica equivalent, the M / SiO2 molar ratio indicates the molar ratio of alkali metal to silicon in silica equivalent, the OH / SiO2 molar ratio indicates the molar ratio of hydroxide ions to silicon in silica equivalent, and the H2O / SiO2 molar ratio indicates the molar ratio of water to silicon in silica equivalent. Each composition ratio in the following molar compositions may be any combination of upper and lower limits.

[0043] SiO2 / Al2O3 molar ratio = 5 or higher, 10 or higher, or 15 or higher 30 or under, 40 or under, or 50 or under SDA / SiO2 molar ratio = 0.01 or higher, 0.03 or higher, or 0.06 or higher 0.10 or less, 0.15 or less, or 0.30 or less M / SiO2 molar ratio = 0.01 or higher, 0.05 or higher, or 0.10 or higher 0.30 or less, 0.50 or less, or 1.0 or less OH / SiO2 molar ratio = 0.01 or higher, 0.05 or higher, or 0.10 or higher 0.30 or less, 0.50 or less, or 1.0 or less H2O / SiO2 molar ratio = 5.0 or higher, 8.0 or higher, or 10.0 or higher 20.0 or less, 30.0 or less, or 50.0 or less

[0044] The raw material composition to be crystallized in the crystallization process may consist only of the alumina source, silica source, alkali source, structure-directing agent source, and water mentioned above, or it may contain other substances.

[0045] In the crystallization process, the raw material composition is crystallized. The crystallization of the raw material composition is not particularly limited, as long as it is possible to crystallize the raw material composition so that a zeolite with the desired skeletal structure is synthesized. A preferred crystallization method is to hydrothermally treat the raw material composition. Hydrothermal treatment can be performed, for example, by placing the raw material composition in a sealed pressure vessel and heating it. Examples of hydrothermal treatment conditions include the following: Processing temperature: 90°C or higher, or 115°C or higher, Below 200℃, or below 180℃ Processing time: 10 hours or more, or 20 hours or more, 72 hours or less, or 48 hours or less Processing pressure: Self-generating pressure

[0046] The crystallization treatment of the raw material composition may be carried out in the presence of a seed crystal. A zeolite may be used as the seed crystal, and it is preferable to use a zeolite with the same skeletal structure as the zeolite to be manufactured. The ratio of the total mass of silicon (Si) and aluminum (Al) of the seed crystal converted to SiO2 and Al2O3, respectively, to the total mass of silicon (Si) and aluminum (Al) of the raw material composition (without seed crystal) converted to SiO2 and Al2O3, respectively (hereinafter also referred to as "seed crystal content") can be exemplified by being 0% to 10% by mass, 0% to 5% by mass, or 0% to 3% by mass. An example of a method for crystallizing the raw material composition in the presence of a seed crystal is a method of crystallizing a mixture obtained by mixing the raw material composition and the seed crystal. The crystallization of the raw material composition may also be carried out without mixing the seed crystal with the raw material composition, i.e., with a seed crystal content of 0% by mass.

[0047] The crystalline product (zeolite) obtained by crystallizing the raw material composition may be subjected to at least one of the following treatments before the ammonium treatment step: washing, drying, and SDA removal. Washing can be done by washing the crystalline product (zeolite) with water. Drying can be done by any method that can physically remove moisture adsorbed on the crystalline product, and is not particularly limited, but for example, a method of treating the crystalline product (zeolite) in air at a temperature of 50°C to 150°C for 2 hours or more can be used. SDA removal can be done by any method that can remove SDA contained in the crystalline product (zeolite), and is not particularly limited, but for example, a method of calcining the crystalline product (zeolite) in an oxidizing atmosphere, preferably air at a temperature of 400°C to 800°C for 1 hour or more can be used.

[0048] In the ammonium treatment process, the crystalline product (zeolite) obtained by crystallizing the raw material composition is brought into contact with an ammonium-containing solution. The ammonium-containing solution is ammonium (NH4 + A solution containing ammonium, and comprising at least an ammonium source and a solvent. The solvent contained in the ammonium-containing solution is ammonium (NH4 + Any solvent capable of containing ) is acceptable, and examples include at least one of alcohol and water, with water being preferred.

[0049] Ammonium sources in ammonium-containing solutions include ammonia or ammonium salts. Ammonium salts include ammonium (NH4) + Any salt containing ammonium is acceptable, and moreover, one or more selected from the group consisting of ammonium carbonate, ammonium chloride, and ammonium nitrate can be used, with ammonium chloride being preferred.

[0050] Ammonium concentration (NH4) of ammonium-containing solution + The concentration is not particularly limited and should be adjusted as appropriate so that a zeolite with a proton cation type is obtained after the calcination process described later.

[0051] The method and conditions for contacting the crystallized product with the ammonium-containing solution are not particularly limited, and may be appropriately adjusted so that a zeolite with a proton cation type can be obtained through the calcination process described later.

[0052] In the ammonium treatment step, by contacting the crystallized product (zeolite) with the ammonium-containing solution, the alkali metal ions contained as counterions in the crystallized product (zeolite) are ion-exchanged with ammonium, and a crystallized product (zeolite) with a cation type of ammonium (NH4 + ) can be obtained.

[0053] In the calcination step, the crystallized product (zeolite with a cation type of ammonium) that has contacted the ammonium-containing solution is calcined. The calcination in the calcination step may be carried out under conditions such that ammonium (NH4 + ) contained as a counterion in the crystallized product (zeolite) is removed, and it is not particularly limited. For example, the crystallized product (zeolite) may be calcined in the air at 400°C or higher and 800°C or lower for 1 hour or longer and 5 hours or shorter.

[0054] In the ammonium treatment step, by calcining the crystallized product (zeolite with a cation type of ammonium), ammonium (NH4 + ) contained as a counterion in the crystallized product (zeolite) is removed, and a zeolite with a cation type of proton is obtained.

[0055] The zeolite contained in the zeolite slurry is not limited to only the zeolite synthesized by the method described above, and zeolites synthesized by other synthesis methods may also be used.

[0056] The zeolite slurry used in the mixing process contains water. While there are no particular limitations on the amount of water in the zeolite slurry, it is preferable that the amount of water is such that the solid content of the zeolite slurry is 5.0% by mass or more, 10.0% by mass or more, or 20.0% by mass or more, from the viewpoint of making it easier for copper ions to be supported on the zeolite. Furthermore, it is preferable that the amount of water in the zeolite slurry is such that the solid content of the zeolite slurry is 90.0% by mass or less, 70.0% by mass or less, or 50.0% by mass or less, in order to make it easier for the zeolite slurry and the copper source to mix. The combination of the upper and lower limits for the solid content concentration of the zeolite slurry is arbitrary, but since copper ions are more easily supported on the zeolite and the zeolite slurry and copper source are more easily mixed, the solid content concentration of the zeolite slurry is preferably 5.0% by mass or more and 90.0% by mass or less, more preferably 10.0% by mass or more and 70.0% by mass or less, and even more preferably 20.0% by mass or more and 50.0% by mass or less.

[0057] The solid content concentration of a zeolite slurry is the ratio of the mass of zeolite to the total mass of zeolite and water contained in the zeolite slurry, and can be calculated from the following formula (1). In the following formula (1), the zeolite mass Wz represents the dry mass [g] of the zeolite contained in the zeolite slurry when heated in air at 600°C for 1 hour, and the water mass Ww represents the mass [g] of water contained in the zeolite slurry. Solid content concentration [mass%] = Zeolite mass Wz / (Zeolite mass Wz + Water mass Ww) × 100 ... (1)

[0058] Furthermore, if other raw materials contained in the zeolite slurry contain water, this can be considered as water contained in the zeolite slurry. For example, if the acid described later is an aqueous solution, the water contained in that aqueous solution can be considered as water contained in the zeolite slurry.

[0059] The zeolite slurry may consist only of zeolite with a proton cation type and water, as described above, or it may further contain other substances (hereinafter simply referred to as "other components"). Examples of such other substances include pH adjusters.

[0060] Examples of pH adjusting agents that can be included in the zeolite slurry include at least one of organic acids and inorganic acids, and from an industrial standpoint, it is preferable that one or more are selected from the group consisting of sulfuric acid, nitric acid, hydrochloric acid, lactic acid, and formic acid. The content of the pH adjusting agent is not particularly limited and can be adjusted as appropriate so that the pH of the zeolite slurry is 2.3 or less.

[0061] Zeolite slurry may be prepared by mixing each of the contained raw materials one by one in any order, by mixing all the contained raw materials simultaneously, or by preparing a precursor (hereinafter also called "zeolite slurry precursor") by mixing two or more of the contained raw materials in advance, and then mixing the remaining raw materials into the zeolite slurry precursor.

[0062] The pH of the zeolite slurry used in the mixing process should be 2.3 or lower. A pH of 2.3 or lower allows copper ions from the copper source to be supported on the zeolite, enabling the production of copper-supported zeolite. Conversely, if the pH of the zeolite slurry exceeds 2.3, copper ions from the copper source become less likely to be supported on the zeolite, making it impossible to produce copper-supported zeolite. Since the pH of the zeolite slurry may fluctuate depending on the mixing state of each raw material, it should be measured when the pH stops fluctuating (for example, when the pH fluctuation over 10 seconds is 0.015 pH or lower). The pH of the zeolite slurry should be measured at 20°C using a general-purpose pH meter (for example, model name: F-72S, manufactured by HORIBA).

[0063] The pH of the zeolite slurry should be 2.3 or lower, but from the viewpoint of easier copper ion support on the zeolite, it is preferably 2.1 or lower, more preferably 2.0 or lower, and even more preferably 1.8 or lower. The lower limit of the pH of the zeolite slurry is not particularly limited, but for example, it may be 0.5 or higher, or 1.0 or higher. The combination of the upper and lower pH limits mentioned above is arbitrary, but from the viewpoint of easier copper ion support on the zeolite, the pH of the zeolite slurry is preferably 0.5 to 2.3, more preferably 0.5 to 2.1, and even more preferably 1.0 to 2.0.

[0064] The copper source used in the mixing process is one or more selected from the group consisting of copper oxide, cuprous oxide, and copper hydroxide. From the viewpoint of making it easier for copper ions to be supported on the zeolite, the copper source used in the mixing process is preferably at least one of copper oxide and copper hydroxide, and more preferably copper oxide.

[0065] The shape of the copper source used in the mixing process is arbitrary, but from the viewpoint of making it easier for copper ions to be supported on the zeolite, it is preferable that it be in powder form. From the viewpoint of making it even easier for copper ions to be supported on the zeolite, the particle size of the powdered copper source at which the cumulative volume from the small particle side in the volume particle size distribution accounts for 50% (hereinafter also referred to as "D50 diameter") is preferably 0.01 μm or more, 0.05 μm or more, 0.1 μm or more, 0.4 μm or more, or 1 μm or more, and preferably 100 μm or less, 50 μm or less, or 20 μm or less. The combination of the upper and lower limits of the D50 diameter as described above is arbitrary, but from the viewpoint of making it even easier for copper ions to be supported on the zeolite, the D50 diameter of the copper source is preferably 0.05 μm or more and 100 μm or less, more preferably 0.1 μm or more and 50 μm or less, more preferably 0.4 μm or more and 20 μm or less, and particularly preferably 1 μm or more and 20 μm or less.

[0066] The volume particle size distribution of the copper source is a volume-based particle size distribution measured using a general laser diffraction / scattering particle size distribution analyzer (e.g., Microtrac MT3300EXII, manufactured by Microtrac-Bell Co., Ltd.). The following conditions can be used for measurement with the laser diffraction / scattering particle size distribution analyzer, and the sample to be measured can be a sample prepared by suspending the copper source in pure water and dispersing it for 2 minutes using an ultrasonic homogenizer set to a frequency of 20 kHz. Measurement range: 0.02~2000μm Particle refractive index: 1.66 Particle permeability: permeation Particle shape: non-spherical Solvent type: Water (pure water) Solvent refractive index: 1.333 Ultrasonic pretreatment: Frequency 20kHz, 2 minutes

[0067] The copper source used in the mixing process is preferably mixed in an amount such that the raw material copper content is 2.0% by mass or more, 2.5% by mass or more, or 2.8% by mass or more, from the viewpoint of making it easier to apply to applications as a nitrogen oxide reduction catalyst at low temperatures, and preferably in an amount such that the copper content is 6.0% by mass or less, 5.5% by mass or less, or 5.0% by mass or less, from the viewpoint of making it easier for copper ions to be supported on the zeolite. The combination of the upper and lower limits of the raw material copper content is arbitrary, but from the viewpoint of making it easier to apply to applications as a nitrogen oxide reduction catalyst at low temperatures and making it easier for copper ions to be supported on the zeolite, the raw material copper content is preferably 2.0% by mass or more and 6.0% by mass or less, more preferably 2.5% by mass or more and 5.5% by mass or less, and even more preferably 2.8% by mass or more and 5.0% by mass or less.

[0068] The copper content of the raw material is the ratio [mass %] of the mass of copper in the copper source to the total mass of zeolite in the zeolite slurry and copper in the copper source, and can be calculated from the following formula (4). In the following formula (4), the zeolite mass Wz represents the dry mass [g] of the zeolite in the zeolite slurry when heated in air at 600°C for 1 hour, and the copper mass Wc represents the mass [g] of copper in the copper source. The copper mass Wc can be calculated from the mass of the copper source and the atomic weight of each atom constituting the copper source. Raw material copper content = copper mass Wc / (zeolite mass Wz+copper mass Wc)×100... (4)

[0069] In the mixing step, a zeolite slurry with a pH of 2.3 or lower is mixed with a copper source. The mixing of the zeolite slurry and copper source can be carried out by any method; for example, the container for mixing the zeolite slurry and copper source may be covered to suppress water evaporation during the mixing process.

[0070] In the mixing process, the mixing temperature of the zeolite slurry and the copper source is not particularly limited, but from the viewpoint of promoting the dissolution of the copper source, it is preferably 10°C or higher, 20°C or higher, 25°C or higher, 30°C or higher, 40°C or higher, 50°C or higher, or 60°C or higher, and from the viewpoint of equipment and economics, it is preferably less than 100°C, 95°C or lower, 90°C or lower, or 70°C or lower. The combination of the upper and lower limits of the mixing temperature as described above is arbitrary, but from the viewpoint of promoting the dissolution of the copper source and from the viewpoint of equipment and economics, the mixing temperature of the zeolite slurry and the copper source is preferably 10°C or higher and less than 100°C, more preferably 20°C or higher and 95°C or lower, and even more preferably 25°C or higher and 90°C or lower.

[0071] In the mixing process, the mixing time between the zeolite slurry and the copper source can be adjusted as appropriate to achieve the desired copper content, and is not particularly limited. However, from the viewpoint of making it easier for copper ions to be supported on the zeolite, it is preferable to have a mixing time of 10 minutes or more, 30 minutes or more, or 60 minutes or more. The upper limit of the mixing time between the zeolite slurry and the copper source is not particularly limited, but for example, it may be 720 minutes or less, or 360 minutes or less. The combination of the upper and lower limits of the mixing time mentioned above is arbitrary, but from the viewpoint of making it easier for copper ions to be supported on the zeolite, the mixing time between the zeolite slurry and the copper source is preferably 10 minutes or more and 720 minutes or less, more preferably 30 minutes or more and 360 minutes or less, and even more preferably 60 minutes or more and 360 minutes or less.

[0072] In the mixing step described above, copper ions are supported on the zeolite by mixing a zeolite slurry with a pH of 2.3 or less with a copper source, thereby producing copper-supported zeolite. The produced copper-supported zeolite may be used as is for a predetermined purpose, or it may be dried before being used for a predetermined purpose. In other words, the manufacturing method of this embodiment may include the mixing step described above and a drying step in which the zeolite (copper-supported zeolite) obtained in the mixing step is dried. The drying process in the drying step can be carried out by any method that can physically remove moisture adsorbed on the zeolite (copper-supported zeolite), and is not particularly limited, but for example, a method in which the zeolite (copper-supported zeolite) is treated in air at a temperature of 50°C to 350°C for 0.5 hours to 24 hours may be used, or a method in which the zeolite (copper-supported zeolite) is treated in air at a temperature of 100°C to 200°C for 1 hour to 20 hours may be used.

[0073] According to the manufacturing method of this embodiment described above, copper ions can be supported on the zeolite, so copper-supported zeolite can be manufactured without firing.

[0074] The copper-supported zeolite produced by the manufacturing method of this embodiment is more readily usable in specific applications such as nitrogen oxide reduction catalysts and hydrocarbon adsorbents, so the copper content is preferably 2.0% by mass or more, 2.5% by mass or more, or 2.8% by mass or more, and preferably 6.0% by mass or less, 5.5% by mass or less, or 5.0% by mass or less. The combination of the upper and lower limits of the copper content described above is arbitrary, but the copper content of the copper-supported zeolite is preferably 2.0% by mass or more and 6.0% by mass or less, more preferably 2.5% by mass or more and 5.5% by mass or less, and even more preferably 2.8% by mass or more and 5.0% by mass or less, in order to facilitate its use in specific applications such as nitrogen oxide reduction catalysts and hydrocarbon adsorbents.

[0075] The copper-supported zeolite produced by the manufacturing method of this embodiment is more readily usable in specific applications such as nitrogen oxide reduction catalysts and hydrocarbon adsorbents, and therefore, it is preferable that the copper oxide content be 10% or less, 5.0% or less, 2.5% or less, 1.0% or less, or 0.5% or less. The lower limit of the copper oxide content is not particularly limited, but for example, it may be 0% or more, or 0.1% or more. The combination of the upper and lower limits of the copper oxide content described above is arbitrary, but the copper oxide content of the copper-supported zeolite is preferably 0% to 5.0%, more preferably 0% to 2.5%, and even more preferably 0% to 1.0%, in order to facilitate its use in specific applications such as nitrogen oxide reduction catalysts and hydrocarbon adsorbents. Note that a copper oxide content of 0% means that the XRD pattern of the copper-supported zeolite does not have an XRD peak caused by copper oxide (an XRD peak with a peak top in the range of 2θ = 38.0° to 39.0°). [Examples]

[0076] The present disclosure will be described in more detail below in the form of examples. However, the present disclosure is not limited to these examples.

[0077] (Identification of crystal structure) XRD measurements of the sample were performed using a standard X-ray diffractometer (instrument name: UltimaIV Protectus, manufactured by Rigaku Corporation). The measurement conditions were as follows: 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 Ultra2) Filter: Ni filter

[0078] The crystal structure of the zeolite was identified by comparing the obtained XRD pattern with a reference pattern. Furthermore, the XRD pattern was analyzed using general analysis software (e.g., SmartLab Studio II, Rigaku Corporation). The following conditions were used for the analysis. 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-off value = 3, χ threshold = 1.5.

[0079] (composition analysis) Hydrofluoric acid (HF concentration: 48 mass%), nitric acid (HNO3 concentration: 60 mass%), and pure water were mixed to obtain an acid solution (HF: 0.96 mass%, HNO3: 1.2 mass%). 2 mg of the sample was dissolved in 10 mL of this acid solution to prepare the sample solution. The sample solution was measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES) using a general ICP instrument (instrument name: OPTIMA5300DV, PerkinElmer). From the composition of the obtained sample (content of silicon, aluminum, copper, sodium, and potassium), the SiO2 / Al2O3 molar ratio, the molar ratio of sodium to aluminum (hereinafter also referred to as "Na / Al molar ratio"), and the molar ratio of potassium to aluminum (hereinafter also referred to as "K / Al molar ratio") were determined. Furthermore, the copper content was determined from the above formula (2) using the composition of the obtained sample.

[0080] (Copper oxide content) A copper oxide sample was prepared in an amount equal to the copper content of the sample measured by the compositional analysis described above. Additionally, zeolite was prepared before copper was supported on the sample. These were mixed to create a reference sample. Copper oxide (CuO) was used as the copper oxide.

[0081] XRD patterns of the measurement sample (copper-supported zeolite) and the reference sample were obtained using the same method as described above for identifying the crystal structure. For each of the XRD patterns of the measurement sample and the reference sample, XRD peaks attributable to copper oxide (XRD peaks with peak tops in the range of 2θ = 38.0° to 39.0°) were separated. For each XRD pattern, the sum of the area intensities of the separated XRD peaks was calculated and these were defined as the area intensity Sc in equation (3a) and the area intensity Rc in equation (3b) above. In addition, for each of the XRD patterns of the measurement sample and the reference sample, XRD peaks attributable to zeolite (XRD peaks with peak tops in the range of 2θ = 20.0° to 21.0°) were separated. For each XRD pattern, the sum of the area intensities of the separated XRD peaks was calculated and these were defined as the area intensity Sz in equation (3a) and the area intensity Rz in equation (3b) above. The area intensity ratio Si of the measurement sample was determined by substituting the area intensity Sc and area intensity Sz into equation (3a), and the area intensity ratio Ri of the reference sample was determined by substituting the area intensity Rc and area intensity Rz into equation (3b). The copper oxide content was determined by substituting the determined area intensity ratios Si and Ri into equation (3).

[0082] The separation of XRD peaks from the XRD pattern was performed using general analysis software (e.g., SmartLab Studio II, manufactured by Rigaku Corporation), and the following conditions were used for the analysis. 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: Peak-top method, σ cut-off value = 3, χ threshold = 1.5

[0083] (Copper content and solids concentration of raw materials) The zeolite, before being incorporated into the zeolite slurry, was heated in air at 600°C for 1 hour. The dry mass [g] of the zeolite was then measured and designated as the zeolite mass Wz in equations (1) and (4) above. The mass of copper contained in the copper source was determined from the mass of the copper source before mixing with the zeolite slurry and the atomic weights of each atom constituting the copper source. This mass was designated as the copper mass Wc in equation (4) above. The mass of water contained in the zeolite slurry was designated as the water mass Ww in equation (1) above. Using the zeolite mass Wz, copper mass Wc, and water mass Ww, the raw material copper content and solid content concentration were calculated from equations (4) and (1), respectively.

[0084] (D50 diameter) The volume particle size distribution of the copper source was determined by measuring the integrated curve using a laser diffraction / scattering particle size distribution analyzer (instrument name: Microtrac MT3300EXII, manufactured by Microtrac-Bell Co., Ltd.). As a pretreatment, the sample was suspended in pure water and dispersed for 2 minutes using an ultrasonic homogenizer set to a frequency of 20 kHz. The measurement conditions were as follows. The D50 diameter was obtained from the obtained integrated volume particle size distribution. Measurement range: 0.02~2000μm Particle refractive index: 1.66 Particle permeability: permeation Particle shape: non-spherical Solvent type: Water (pure water) Solvent refractive index: 1.333 Ultrasonic pretreatment: Frequency 20kHz, 2 minutes

[0085] Synthesis Example 1 CHA-type zeolite was synthesized by a method corresponding to Example 2 of Japanese Patent No. 7283046. Specifically, a 25 wt% DMECHABr aqueous solution, a 25 wt% DMECHAOH aqueous solution, a 48% sodium hydroxide aqueous solution, a 48 wt% potassium hydroxide aqueous solution, pure water, and amorphous aluminosilicate (SiO2 / Al2O3 = 24.3) were mixed to obtain a raw material composition having the following molar composition. SSZ-13 was mixed as a seed crystal to the obtained raw material composition so that the seed crystal content was 1.0 mass. The molar ratio of DMECHAOH to DMECHABr in the raw material composition was 1 / 1. SiO2 / Al2O3 molar ratio = 24.3 DMECHA / SiO2 molar ratio = 0.08 Na / SiO2 molar ratio = 0.04 K / SiO2 molar ratio = 0.08 H2O / SiO2 molar ratio = 18.0 OH / SiO2 molar ratio = 0.16

[0086] The raw material composition, mixed with seed crystals, was filled into a sealed container and subjected to hydrothermal treatment under conditions of self-generating pressure, 150°C, and 48 hours while rotating and stirring the container at 55 rpm. The resulting crystallized material was separated into solid and liquid phases, washed with deionized water, and then dried in air at 110°C. The crystallized material was a single phase of CHA-type zeolite (crystalline aluminosilicate) with an SiO2 / Al2O3 molar ratio of 22.9.

[0087] The dried CHA-type zeolite was ion-exchanged with an aqueous ammonium chloride solution to obtain CHA-type zeolite with an ammonium cation type. The CHA-type zeolite with an ammonium cation type was further calcined in air at 600°C for 2 hours to obtain CHA-type zeolite with a proton cation type (hereinafter also referred to as "proton-type CHA-type zeolite"). The proton-type CHA-type zeolite in this synthesis example had a Na / Al molar ratio of 0.002 or less (below the detection limit) and a K / Al molar ratio of 0.002 or less (below the detection limit).

[0088] Example 1 8.35 g of proton-type CHA zeolite from Synthesis Example 1 was mixed with 14 g of pure water and 1 g of 2N sulfuric acid (manufactured by Kishida Chemical Co., Ltd.) using a magnetic stirrer to obtain a zeolite slurry. The pH of the obtained zeolite slurry is shown in Table 1 below. 0.31 g of copper oxide with a D50 diameter of 5.0 μm (product number: 038-04345, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added to this slurry and mixed using a magnetic stirrer at room temperature (20°C) for 1 hour to obtain copper-supported CHA zeolite. In this example, the raw material copper content was 2.9% by mass, and the solid content concentration of the zeolite slurry was 35%. The obtained copper-supported CHA zeolite was dried in air at 110°C for 15 hours to obtain the copper-supported CHA zeolite of this example.

[0089] The copper-supported CHA-type zeolite in this embodiment did not have any XRD peaks (XRD peaks with peak tops in the range of 2θ = 38.0° to 39.0°) attributable to copper oxides in its XRD pattern (below the detection limit), and had a copper oxide content of 0% and a copper content of 2.9 mass%, making it a copper-supported CHA-type zeolite (crystalline aluminosilicate).

[0090] Example 2 The preparation was carried out in the same manner as in Example 1, except that 1 g of 1 N nitric acid (manufactured by Kishida Chemical Co., Ltd.) was added instead of 1 g of 2 N sulfuric acid, to obtain the copper-supported CHA-type zeolite of this example. In this example, the copper content of the raw material was 2.9% by mass, and the solid content concentration of the zeolite slurry was 35%.

[0091] The copper-supported CHA-type zeolite in this embodiment did not have any XRD peaks (XRD peaks with peak tops in the range of 2θ = 38.0° to 39.0°) attributable to copper oxides in its XRD pattern (below the detection limit), and had a copper oxide content of 0% and a copper content of 2.9 mass%, making it a copper-supported CHA-type zeolite (crystalline aluminosilicate).

[0092] Example 3 The preparation was carried out in the same manner as in Example 1, except that 6 g of lactic acid (product code: 128-00056, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added instead of 1 g of 2N sulfuric acid, to obtain the copper-supported CHA-type zeolite of this example. In this example, the copper content of the raw material was 2.9% by mass, and the solid content concentration of the zeolite slurry was 35%.

[0093] The copper-supported CHA-type zeolite in this embodiment did not have any XRD peaks (XRD peaks with peak tops in the range of 2θ = 38.0° to 39.0°) attributable to copper oxides in its XRD pattern (below the detection limit), and had a copper oxide content of 0% and a copper content of 2.9 mass%, making it a copper-supported CHA-type zeolite (crystalline aluminosilicate).

[0094] Example 4 The preparation was carried out in the same manner as in Example 1, except that 1 g of formic acid (special grade, manufactured by Kishida Chemical Co., Ltd.) was added instead of 1 g of 2N sulfuric acid, to obtain the copper-supported CHA-type zeolite of this example. In this example, the copper content of the raw material was 2.9% by mass, and the solid content concentration of the zeolite slurry was 36%.

[0095] The copper-supported CHA-type zeolite in this embodiment did not have any XRD peaks (XRD peaks with peak tops in the range of 2θ = 38.0° to 39.0°) attributable to copper oxides in its XRD pattern (below the detection limit), and had a copper oxide content of 0% and a copper content of 2.9 mass%, making it a copper-supported CHA-type zeolite (crystalline aluminosilicate).

[0096] Example 5 The preparation was carried out in the same manner as in Example 1, except that 0.5 g of 2N sulfuric acid and 0.5 g of 1N nitric acid were added instead of 1 g of 2N sulfuric acid, to obtain the copper-supported CHA-type zeolite of this example. In this example, the copper content of the raw material was 2.9% by mass, and the solid content concentration of the zeolite slurry was 35%.

[0097] The copper-supported CHA-type zeolite in this embodiment did not have any XRD peaks (XRD peaks with peak tops in the range of 2θ = 38.0° to 39.0°) attributable to copper oxides in its XRD pattern (below the detection limit), and had a copper oxide content of 0% and a copper content of 2.9 mass%, making it a copper-supported CHA-type zeolite (crystalline aluminosilicate).

[0098] Example 6 The preparation was carried out in the same manner as in Example 1, except that 0.5 g of 2N sulfuric acid and 0.5 g of 2N hydrochloric acid were added instead of 1 g of 2N sulfuric acid, to obtain the copper-supported CHA-type zeolite of this example. In this example, the copper content of the raw material was 2.9% by mass, and the solid content concentration of the zeolite slurry was 35%.

[0099] The copper-supported CHA-type zeolite in this embodiment did not have any XRD peaks (XRD peaks with peak tops in the range of 2θ = 38.0° to 39.0°) attributable to copper oxides in its XRD pattern (below the detection limit), and had a copper oxide content of 0% and a copper content of 2.9 mass%, making it a copper-supported CHA-type zeolite (crystalline aluminosilicate).

[0100] Example 7 The preparation was carried out in the same manner as in Example 1, except that 0.5 g of 1N nitric acid and 0.5 g of 2N hydrochloric acid were added instead of 1 g of 2N sulfuric acid, to obtain the copper-supported CHA-type zeolite of this example. In this example, the copper content of the raw material was 2.9% by mass, and the solid content concentration of the zeolite slurry was 35%.

[0101] The copper-supported CHA-type zeolite in this embodiment did not have any XRD peaks (XRD peaks with peak tops in the range of 2θ = 38.0° to 39.0°) attributable to copper oxides in its XRD pattern (below the detection limit), and had a copper oxide content of 0% and a copper content of 2.9 mass%, making it a copper-supported CHA-type zeolite (crystalline aluminosilicate).

[0102] Example 8 The preparation was carried out in the same manner as in Example 1, except that 0.5 g of 2N sulfuric acid and 0.5 g of lactic acid were added instead of 1 g of 2N sulfuric acid, to obtain the copper-supported CHA-type zeolite of this example. In this example, the copper content of the raw material was 2.9% by mass, and the solid content concentration of the zeolite slurry was 35%.

[0103] The copper-supported CHA-type zeolite in this embodiment did not have any XRD peaks (XRD peaks with peak tops in the range of 2θ = 38.0° to 39.0°) attributable to copper oxides in its XRD pattern (below the detection limit), and had a copper oxide content of 0% and a copper content of 2.9 mass%, making it a copper-supported CHA-type zeolite (crystalline aluminosilicate).

[0104] Reference example 1 A copper nitrate solution was prepared by dissolving 1.05 g of copper nitrate trihydrate in 3.4 g of pure water. This copper nitrate solution was added dropwise to 10.0 g of the proton-type CHA zeolite from Synthesis Example 1, and the mixture was impregnated and mixed in a mortar for 10 minutes. The impregnated and mixed CHA zeolite was dried overnight at 110°C, and then calcined in air at 550°C for 1 hour to obtain copper-supported CHA zeolite, which was used as the copper-supported CHA zeolite for this reference example.

[0105] The copper-supported CHA-type zeolite in this reference example did not exhibit any XRD peaks attributable to copper oxides (XRD peaks with peak tops in the range of 2θ = 38.0° to 39.0°) in its XRD pattern (below the detection limit), indicating a copper oxide content of 0% and a copper content of 2.9 mass%, making it a copper-supported CHA-type zeolite (crystalline aluminosilicate).

[0106] Comparative Example 1 The preparation was carried out in the same manner as in Example 1, except that 0.3 g of formic acid was added instead of 1 g of 2N sulfuric acid, to obtain the copper-supported CHA-type zeolite of this comparative example. In this comparative example, the copper content of the raw material was 2.9% by mass, and the solid content concentration of the zeolite slurry was 36%.

[0107] The copper-supported CHA-type zeolite in this comparative example exhibited an XRD peak in its XRD pattern attributable to copper oxide (an XRD peak with its peak top in the range of 2θ = 38.0° to 39.0°), and was a copper-supported CHA-type zeolite (crystalline aluminosilicate) with a copper oxide content of 97.2% and a copper content of 2.9% by mass.

[0108] Comparative Example 2 A CHA-type zeolite with an ammonium cation was prepared during the manufacturing process of Synthesis Example 1. The copper-supported CHA-type zeolite of this comparative example was obtained by preparing the same method as in Example 2, except that the prepared CHA-type zeolite (a CHA-type zeolite with an ammonium cation) was used instead of the proton-type CHA-type zeolite. In this comparative example, the copper content of the raw material was 2.9% by mass, and the solid content concentration of the zeolite slurry was 35%.

[0109] The copper-supported CHA-type zeolite in this comparative example exhibited an XRD peak in its XRD pattern attributable to copper oxide (an XRD peak with its peak top in the range of 2θ = 38.0° to 39.0°), and was a copper-supported CHA-type zeolite (crystalline aluminosilicate) with a copper oxide content of 71.3% and a copper content of 2.9% by mass.

[0110] Table 1 below shows the characteristics of each raw material used in the examples and comparative examples, as well as the characteristics of the copper-supported CHA-type zeolite obtained in the examples and comparative examples. The pH of the zeolite slurry in Table 1 below is the pH at which the pH stopped fluctuating after mixing each raw material (zeolite, pure water, and acid) contained in the zeolite slurry (the pH was determined to have stopped fluctuating when the pH fluctuation over 10 seconds was 0.015 pH or less (standard / initial setting value of the auto-hold mode of the F-72S)). The pH of the zeolite slurry was measured at 20°C using a general pH meter (device name: F-72S, manufactured by HORIBA). [Table 1]

[0111] As shown in Table 1 above, in the manufacturing methods of Examples 1 to 8, where the pH of the zeolite slurry mixed with the copper source was 2.3 or less, and the cation type of the zeolite contained in the zeolite slurry was proton, the copper content was 2.9 by mass and the copper oxide content was 0%, indicating that copper ions were supported on the CHA-type zeolite. Furthermore, in the manufacturing methods of Examples 1 to 8, since copper ions were supported on the zeolite without the need for calcination, it was also understood that calcination was unnecessary and copper-supported zeolite could be produced efficiently.

[0112] On the other hand, in the production method of Comparative Example 1, where the pH of the zeolite slurry mixed with the copper source exceeded 2.3, the copper content was 2.9 by mass, similar to Examples 1-8, but the copper oxide content was 97.2%, indicating that most of the copper was supported on the CHA-type zeolite as copper oxide. Similarly, in the production method of Comparative Example 2, where the cation type of the zeolite contained in the zeolite slurry was ammonium, the copper content was 2.9 by mass, similar to Examples 1-8, but the copper oxide content was 71.3%, indicating that most of the copper was supported on the CHA-type zeolite as copper oxide. From these results, it was understood that raising the pH of the zeolite slurry above 2.3 or using ammonium as the cation type of the zeolite contained in the zeolite slurry is unsuitable for producing copper-supported zeolite.

Claims

1. The process includes a step of mixing a zeolite slurry containing a zeolite whose cation type is at least proton and water with one or more copper sources selected from the group consisting of copper oxide, cuprous oxide and copper hydroxide. The pH of the zeolite slurry is 2.3 or less. A method for producing a copper-supported zeolite, wherein the zeolite has a CHA skeletal structure.

2. The SiO of the zeolite ２ / Al ２ O ３ A method for producing copper-supported zeolite according to claim 1, wherein the molar ratio is 10 or more and less than 80.

3. The method for producing copper-supported zeolite according to claim 1 or 2, wherein the zeolite slurry further comprises one or more selected from the group consisting of sulfuric acid, nitric acid, hydrochloric acid, lactic acid, and formic acid.

4. The method for producing copper-supported zeolite according to claim 1 or 2, wherein the copper source is copper oxide.

5. The method for producing copper-supported zeolite according to claim 1 or 2, wherein the zeolite slurry has a solid content concentration of 15% by mass or more and 90% by mass or less, as determined from the following formula (1). Solid content concentration = Zeolite mass Wz / (Zeolite mass Wz + Water mass Ww) × 100 ... (1) In the above formula (1), the zeolite mass Wz represents the dry mass [g] of the zeolite contained in the zeolite slurry when heated in air at 600°C for 1 hour, and the water mass Ww represents the mass [g] of water contained in the zeolite slurry.

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