Amorphous aluminosilicate and method for producing CHA-type zeolite using the same

Abstract

The objective is to provide at least one of the following: an amorphous aluminosilicate suitable for producing CHA-type zeolite in high yield without requiring SDA, a method for producing the same, and a method for producing CHA-type zeolite using the same as a starting material. [Solution] An amorphous aluminosilicate for producing CHA-type zeolite, wherein the UV-Raman spectrum has wavenumbers of 750-850 cm⁻¹. -1 For the maximum intensity I1 of the band, wavenumbers 400-550 cm -1 Amorphous aluminosilicate in which the ratio of the maximum intensity I2 of the band is 4.0 or higher.

Description

Technical Field

[0001] The present disclosure relates to an amorphous aluminosilicate suitable as a starting material for CHA-type zeolite and a method for producing CHA-type zeolite using the same as a starting material.

Background Art

[0002] CHA-type zeolite is generally synthesized using an organic structure-directing agent (hereinafter also referred to as "SDA") such as N,N,N-trimethyladamantammonium salt (for example, Non-Patent Document 1). However, SDA is expensive and, depending on the use of CHA-type zeolite, it is necessary to remove it by performing a treatment such as calcination. Therefore, in recent years, methods for synthesizing CHA-type zeolite without using SDA (hereinafter also referred to as "SDA-free synthesis method") have been studied.

[0003] Non-Patent Document 2 describes that CHA-type zeolite having a silica-to-alumina molar ratio (hereinafter also referred to as "SiO2 / Al2O3 molar ratio") of about 7 can be obtained by an SDA-free synthesis method using sodium and potassium (Na / K system) as alkali metals as starting materials. Non-Patent Document 3 describes that CHA-type zeolite having a SiO2 / Al2O3 molar ratio of 10.4 can be obtained by an SDA-free synthesis method using sodium and cesium (Na / Cs system) as alkali metals as starting materials.

Prior Art Documents

Non-Patent Documents

[0004]

Non-Patent Document 1

Non-Patent Document 2

Non-Patent Document 3

[0005] The object of this disclosure is to provide at least one of the following: an amorphous aluminosilicate suitable for producing CHA-type zeolite in high yield without requiring SDA, a method for producing the same, and a method for producing CHA-type zeolite using the same as a starting material. [Means for solving the problem]

[0006] The inventors have discovered that amorphous aluminosilicate, obtained by substituting boron with aluminum in borosilicate, is suitable as a starting material for the production of CHA-type zeolite, and have completed the present invention.

[0007] In other words, the gist of this disclosure is as follows: [1] Amorphous aluminosilicate for producing CHA-type zeolite, wherein the UV-Raman spectrum has wavenumbers of 750-850 cm⁻¹ -1 For the maximum intensity I1 of the band, wavenumbers 400-550 cm -1 Amorphous aluminosilicate in which the ratio of the maximum intensity I2 of the band is 4.0 or higher. [2] The amorphous aluminosilicate according to [1], wherein the molar ratio of silica to alumina is 5 or more and 20 or less. [3] A method for producing amorphous aluminosilicate according to [1] or [2] above, comprising the step of substituting boron atoms contained in amorphous borosilicate with aluminum atoms. [4] A method for producing a CHA-type zeolite, comprising the step of crystallizing a composition comprising the amorphous aluminosilicate, alkali source and water described in [1] or [2] above. [Effects of the Invention]

[0008] This disclosure provides at least one of the following: an amorphous aluminosilicate suitable for producing CHA-type zeolite in high yield without requiring SDA; a method for producing the same; and a method for producing CHA-type zeolite using the same as a starting material. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 shows the XRD patterns of amorphous borosilicate (precursor) from Example 1 and Example 2, and amorphous aluminosilicate from Example 1, Example 2, and Comparative Example 1. [Figure 2] Figure 2 shows the UV-Raman spectra of amorphous aluminosilicates from Example 1 and Example 2. [Figure 3] Figure 3 shows the XRD patterns of CHA-type zeolite from Example 3, Example 4, and Comparative Example 3. [Figure 4] Figure 4 shows scanning electron microscope (SEM) images (scale in the figure is 1 μm) of the CHA-type zeolites of Example 3 and Example 4. [Modes for carrying out the invention]

[0010] The present disclosure will be described below with reference to an example of its embodiment. The terms used in this embodiment are defined as follows:

[0011] 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 the atoms of a metal atom and a metalloid atom (hereinafter also referred to as "metal / metalloid atom"). Examples of metal 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).

[0012] 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.

[0013] 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, for example, by comparing it with the XRD pattern (hereinafter also referred to as the "reference pattern") described in Zeolite Framework Types on the International Zeolite Association's website (http: / / www.iza-structure.org / databases / ). Note that, with respect to the skeletal structure of zeolites, the terms skeletal structure, crystalline structure, and crystalline phase are used synonymously.

[0014] In this embodiment, the XRD pattern can be obtained from an XRD measurement under the following conditions. The XRD pattern can be measured using a general powder X-ray diffractometer (e.g., Ultima IV, manufactured by Rigaku). Acceleration current / voltage: 40mA / 40kV Radiation source: CuKα radiation (λ=1.5406Å) Measurement mode: Step scan Scanning conditions: 10° / min Measurement range: 2θ = 3° to 50° Divergence vertical limiting slit: 10mm Divergence / Induction Slit: 1° Scattering slit: 1° Light-receiving slit: 0.30mm Detector: Semiconductor detector (D / teX Ultra2) Filter: Not used

[0015] Aluminosilicate is a composite oxide having a structure consisting of repeating networks of aluminum (Al) and silicon (Si) mediated by oxygen (O). Aluminosilicate may contain other metal / metalloid atoms (hereinafter also referred to as "X1 atoms") as constituent atoms, as long as aluminum (Al) is the dominant atom among the constituent atoms excluding silicon (Si) and oxygen (O). Note that aluminum (Al) being the dominant atom among the constituent atoms excluding silicon (Si) and oxygen (O) means that the molar ratio of aluminum (Al) to X1 atoms (hereinafter also referred to as the "Al / X1 molar ratio") is greater than 1. If aluminosilicate contains two or more types of X1 atoms, the total number of moles of X1 atoms should be used for X1 (the number of moles of X1 atoms) in the Al / X1 molar ratio. Furthermore, in the following explanation, the metallic and metalloid atoms (i.e., aluminum (Al), silicon (Si), and X1 atoms) that make up "aluminosilicate" will be collectively referred to as T1 atoms.

[0016] Among "aluminosilicates," those with crystalline XRD peaks in their XRD pattern are called "crystalline aluminosilicates," and those without crystalline XRD peaks are called "amorphous aluminosilicates." Note that zeolites containing aluminum (Al) and silicon (Si) as T atoms, and T atoms other than aluminum (Al) and silicon (Si) (hereinafter referred to as "T") X1 The molar ratio of aluminum (Al) to atoms (also called "atoms") (hereinafter referred to as "Al / T") X1 Zeolites with a molar ratio (also called the "molar ratio") greater than 1 are classified as crystalline aluminosilicates. X1 If atoms are present, Al / TX1 T in molar ratio X1 (T X1 (number of moles of T atoms), the total number of moles of T atoms may be used. X1 For the total number of moles of atoms, the total number of moles of T atoms may be used.

[0017] "Borosilicate" is a composite oxide having a structure composed of a repeating network of boron (B) and silicon (Si) via oxygen (O). "Borosilicate" may contain metal / semimetal atoms other than boron (B) and silicon (Si) (hereinafter also referred to as "X2 atoms") as constituent atoms, provided that boron (B) is the main atom among the constituent atoms excluding silicon (Si) and oxygen (O). Note that the fact that boron (B) is the main atom among the constituent atoms excluding silicon (Si) and oxygen (O) means that the molar ratio of boron (B) to X2 atoms (hereinafter also referred to as "B / X2 molar ratio") exceeds 1. When two or more types of X2 atoms are contained in the borosilicate, for X2 (number of moles of X2 atoms) in the B / X2 molar ratio, the total number of moles of X2 atoms may be used.

[0018] Among "borosilicates", those having crystalline XRD peaks in their XRD patterns are "crystalline borosilicates", and those not having crystalline XRD peaks are "amorphous borosilicates". Note that a zeolite containing boron (B) and silicon (Si) as T atoms, and having a molar ratio of boron (B) to T atoms other than boron (B) and silicon (Si) (hereinafter also referred to as "T atoms") (hereinafter also referred to as "B / T molar ratio") exceeding 1 corresponds to a crystalline borosilicate. When two or more types of T atoms are contained in the zeolite, for T (number of moles of T atoms) in the B / T molar ratio, the total number of moles of T atoms may be used. X2 T atoms X2 molar ratio X2 T atoms X2 molar ratio X2 (T X2 (number of moles of T atoms), the total number of moles of T atoms may be used. X2 For the total number of moles of atoms, the total number of moles of T atoms may be used.

[0019] Crystalline XRD peaks are peaks whose peak top 2θ is identified and detected in the analysis of XRD patterns using general analysis software (e.g., SmartLab Studio II, manufactured by Rigaku Corporation). Peaks whose peak top 2θ is identified and detected in the analysis of XRD patterns using general analysis software (i.e., crystalline XRD peaks) include peaks with a full width at half maximum (FMAX) of 2θ = 0.50° or less.

[0020] The composition in this embodiment, such as the molar ratio of silica to alumina (SiO2 / Al2O3 molar ratio) and the molar ratio of silica to boron oxide (diboron trioxide) (hereinafter also referred to as "SiO2 / B2O3 molar ratio"), 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, ICPE-9820, manufactured by Shimadzu Corporation). For compositional analysis, a sample solution obtained by dissolving the sample in an aqueous hydrofluoric acid solution can be used.

[0021] The amorphous aluminosilicate 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 include any combination.

[0022] The amorphous aluminosilicate of this embodiment is an amorphous aluminosilicate for producing CHA-type zeolite, and in the UV-Raman spectrum, wavenumber 750-850 cm⁻¹ -1 For the maximum intensity I1 of the band, wavenumbers 400-550 cm -1 The ratio of the maximum intensity I2 of the band (hereinafter also referred to as the "Raman intensity ratio I2 / I1") is 4.0 or higher.

[0023] In the amorphous aluminosilicate of this embodiment, the Raman intensity ratio I2 / I1 may be 4.0 or higher, but from the viewpoint of further improving the yield of the CHA-type zeolite produced, it is preferable that it be 4.1 or higher. The upper limit of the Raman intensity ratio I2 / I1 is not particularly limited, but for example, it may be 12 or less, 10 or less, or 8 or less. The combination of the upper and lower limits of the Raman intensity ratio I2 / I1 described above is arbitrary, but from the viewpoint of further improving the yield of the CHA-type zeolite produced, the Raman intensity ratio I2 / I1 is preferably 4.0 or higher and 12 or lower, more preferably 4.1 or higher and 10 or lower, and even more preferably 4.1 or higher and 8 or lower.

[0024] The UV-Raman spectrum measured to determine the Raman intensity ratio I2 / I1 can be obtained using a general-purpose micro-laser Raman spectrometer (e.g., LabRAM HR Evolution, Horiba, Ltd.), and the following conditions can be used for measurement. Laser wavelength: 325nm Laser power: 6mW Exposure time: 100 seconds Number of times: 2

[0025] In the UV-Raman spectrum, wavenumbers 750-850 cm⁻¹ -1 The maximum intensity I1 of the band is based on the minimum intensity in the range from 200 nm to 900 nm, and this is used as the baseline for wavenumbers 750 to 850 cm⁻¹. -1 This can be determined by subtracting it from the maximum intensity measurement of the band. Similarly, in the UV-Raman spectrum, wavenumbers 400-550 cm⁻¹ -1 The maximum intensity I2 of the band is based on the minimum intensity in the range from 200 nm to 900 nm, and this is used as the baseline for wavenumbers 400 to 550 cm⁻¹. -1 It can be determined by subtracting it from the measured maximum intensity of the band. The Raman intensity ratio I2 / I1 can be calculated from the obtained maximum intensities I1 and I2.

[0026] UV-Raman spectrum with wavenumbers of 750-850 cm⁻¹ -1 The band (hereinafter referred to as "B") 750-850 It is also called ). ) has a wave number of 750-850 cm -1 A broad peak having at least one extremum (in other words, at least one inflection point) within the range, B 750-850 The maximum intensity I1 corresponds to wavenumbers of 750-850 cm. -1 B exists within the range 750-850 This is the local maximum value. 750-850 The full width at half maximum is not particularly limited, but for example, 30 cm -1 More than 110cm -1 Below, 40cm -1 More than 90cm -1 The following, or 60cm -1 More than 90cm -1 The following are some examples. In this embodiment, the full width at half maximum of the band (peak) can be determined by using the minimum intensity in the range of 200 nm to 900 nm as the baseline, finding the maximum value of that band (peak), and using the width of the band (peak) at half the intensity of the found maximum value.

[0027] Furthermore, in the UV-Raman spectrum, wavenumbers 400-550 cm⁻¹ -1 The band (hereinafter referred to as "B") 400-550 It is also called ). ) has a wave number of 400-550cm -1 A broad peak having at least one extremum (in other words, at least one inflection point) within the range, B 400-550 The maximum intensity I2 corresponds to wavenumbers of 400-550 cm. -1 B exists within the range 400-550 This is the local maximum value. 400-550 The full width at half maximum is not particularly limited, but for example, 100 cm -1 More than 250cm -1 Below, 120cm -1 More than 220cm -1 The following, or 120cm -1 over 190cm -1 The following are some examples:

[0028] B in the UV-Raman spectrum 750-850 and B 400-550 These bands correspond to the T1-O-T1 symmetric stretching and the T1-O-T1 asymmetric stretching of the oxygen four-membered ring, respectively. The Raman intensity ratio I2 / I1 functions as a parameter representing the relative amount of units consisting of the ring structure of the oxygen four-membered ring contained in the amorphous aluminosilicate (hereinafter also referred to as "four-membered ring units"). Note that T1-O-T1 of the oxygen four-membered ring represents the bond of the T1 atom via the oxygen atom in the oxygen four-membered ring. Therefore, the amorphous aluminosilicate of this embodiment, with a Raman intensity ratio I2 / I1 of 4.0 or higher, has a structure rich in four-membered ring units, thereby promoting the crystallization of CHA-type zeolite without the use of organic structure-determining agents (SDA). Although the reason why amorphous aluminosilicate, which is rich in 4-membered ring units, promotes the crystallization of CHA-type zeolites is not yet clear, it is presumed that the 4-membered oxygen ring units contained in amorphous aluminosilicate are readily converted not only into 4-membered oxygen rings that constitute CHA-type zeolites, but also into 6-membered oxygen rings and 8-membered oxygen rings that constitute CHA-type zeolites, thereby promoting the crystallization of CHA-type zeolites.

[0029] In the amorphous aluminosilicate of this embodiment, the SiO2 / Al2O3 molar ratio is not particularly limited, but it is preferably 5 or more, 6 or more, or 7 or more, and preferably 20 or less, 18 or less, or 15 or less, in order to facilitate the application of the manufactured CHA-type zeolite to SCR (Selective Catalytic Reduction) applications. The combination of the upper and lower limits of the SiO2 / Al2O3 molar ratio described above is arbitrary, but in order to facilitate the application of the manufactured CHA-type zeolite to SCR applications, the SiO2 / Al2O3 molar ratio is preferably 5 or more and 20 or less, more preferably 6 or more and 20 or less, even more preferably 6 or more and 18 or less, and particularly preferably 7 or more and 15 or less.

[0030] The amorphous aluminosilicate of this embodiment may consist only of aluminum (Al), silicon (Si), and oxygen (O). However, if aluminum (Al) is the dominant atom among the constituent atoms excluding silicon (Si) and oxygen (O), it may also contain an X1 atom in addition to aluminum (Al), silicon (Si), and oxygen (O). The X1 atom may be any metal / metalloid atom other than aluminum (Al) and silicon (Si), for example, boron (B).

[0031] The amorphous aluminosilicate of this embodiment may contain X1 atoms, but from the viewpoint of further improving the yield of the CHA-type zeolite produced, it is preferable that it substantially does not contain X1 atoms (in other words, that it is composed only of aluminum (Al), silicon (Si), and oxygen (O)). If the amorphous aluminosilicate of this embodiment contains X1 atoms, the amount of X1 atoms can be appropriately adjusted within the range where the Al / X1 molar ratio exceeds 1. It should be noted that substantially not containing a predetermined component (atom) means that the component (atom) is not detectable (below the detection limit).

[0032] Next, the method for producing amorphous aluminosilicate according to this embodiment will be described.

[0033] The amorphous aluminosilicate of this embodiment can be produced by a manufacturing method that includes a step of substituting boron (B) contained in amorphous borosilicate with aluminum (Al) (hereinafter also referred to as the "boron substitution step").

[0034] The amorphous borosilicate used in the boron substitution process is not particularly limited, but from the viewpoint of facilitating the production of amorphous aluminosilicate with a Raman intensity ratio I2 / I1 of 4.0 or higher, it is preferable that the SiO2 / B2O3 molar ratio is 0.5 or higher, 1 or higher, or 1.5 or higher, and preferably 6 or lower, 5.5 or lower, or 5 or lower. The combination of the upper and lower limits of the SiO2 / B2O3 molar ratio described above is arbitrary, but from the viewpoint of facilitating the production of amorphous aluminosilicate with a Raman intensity ratio I2 / I1 of 4.0 or higher, it is preferable that the SiO2 / B2O3 molar ratio of the amorphous borosilicate used in the boron substitution process is 0.5 or higher and 6 or lower, more preferably 1 or higher and 5 or lower, and even more preferably 1.5 or higher and 5 or lower.

[0035] The amorphous borosilicate used in the boron substitution process may consist only of boron (B), silicon (Si), and oxygen (O). However, if boron (B) is the dominant atom among the constituent atoms excluding silicon (Si) and oxygen (O), it may also contain X2 atoms in addition to boron (B), silicon (Si), and oxygen (O). The X2 atoms may be any metal / metalloid atom other than boron (B) and silicon (Si), for example, aluminum (Al).

[0036] Furthermore, while the amorphous borosilicate used in the boron substitution process may contain X2 atoms, it is preferable that it substantially contains no X2 atoms (in other words, that it is composed only of boron (B), silicon (Si), and oxygen (O)) from the viewpoint of facilitating the production of amorphous aluminosilicate with a Raman intensity ratio I2 / I1 of 4.0 or higher. If the amorphous borosilicate used in the boron substitution process contains X2 atoms, the X2 atom content can be appropriately adjusted within a range where the B / X2 molar ratio exceeds 1.

[0037] The amorphous borosilicate used in the boron substitution process can be manufactured by conventionally known manufacturing methods. One example of a method for manufacturing amorphous borosilicate used in the boron substitution process is a method of mixing a composition containing a silicon source, a boron source, a sodium source, and water (hereinafter also referred to as "raw material composition A").

[0038] The silicon source contained in raw material composition A may be any compound containing silicon (Si), for example, one or more selected from the group consisting of silica sol, fumed silica, colloidal silica, precipitated silica, and sodium silicate, with sodium silicate being preferred.

[0039] The boron source contained in raw material composition A may be any compound containing boron (B), and examples include one or more selected from the group consisting of boric acid, boron oxide, and sodium borate, with boric acid being preferred.

[0040] The sodium source included in raw material composition A may be any compound containing sodium (Na), for example, at least one of sodium hydroxide and sodium chloride. If other raw materials, such as a silicon source, are compounds containing sodium, those compounds may be used as the sodium source.

[0041] The water contained in raw material composition A may be one or more selected from the group consisting of distilled water, deionized water, and pure water. The water contained in raw material composition A may also be water derived from other starting materials, such as water included as a solvent or structured water.

[0042] The composition of raw material composition A can be appropriately set according to the composition of the amorphous borosilicate to be manufactured, but from the viewpoint of making it easier to manufacture amorphous aluminosilicate with a Raman intensity ratio I2 / I1 of 4.0 or higher, the following composition is preferred. In the following composition, the B2O3 / Na2O molar ratio indicates the molar ratio of boron oxide (diboron trioxide) to sodium oxide, the Na / Si molar ratio indicates the molar ratio of sodium to silicon, and the H2O / Si molar ratio indicates the molar ratio of water to silicon. B2O3 / Na2O molar ratio = 0.6 or higher, 0.8 or higher, or 0.9 or higher, and 3 or less, 2.5 or less, or 2 or less Na / Si molar ratio = 0.35 or higher, 0.4 or higher, or 0.45 or higher, and 1 or less, 0.9 or less, or 0.8 or less H2O / Si molar ratio = 15 or higher, 25 or higher, or 30 or higher, 200 or less, 160 or less, or 120 or less

[0043] From the viewpoint of facilitating the production of amorphous aluminosilicate with a Raman intensity ratio I2 / I1 of 4.0 or higher, the composition of raw material composition A is more preferably as shown below. B2O3 / Na2O molar ratio = 0.6 to 3 More preferably, 0.9 or more and 2 or less Na / Si molar ratio = 0.35 or greater and 1 or less More preferably, 0.45 or more and 0.8 or less H2O / Si molar ratio = 15 to 200 More preferably, 30 to 120

[0044] The raw material composition A may consist only of the silicon source, boron source, sodium source and water described above, or it may further contain other substances (hereinafter simply referred to as "other substance A"). Examples of such other substance A include an alumina source. Examples of alumina sources include one or more selected from the group consisting of aluminum isopropoxide, aluminum sulfate, aluminum nitrate, aluminum chloride, aluminum hydroxide, metallic aluminum, pseudoboehmite, and alumina sol.

[0045] Furthermore, while raw material composition A may contain other substances A such as an alumina source, it is preferable that it substantially contains other substances A such as an alumina source from the viewpoint of making it easier to produce amorphous aluminosilicate with a Raman intensity ratio I2 / I1 of 4.0 or higher. If raw material composition A contains other substances A, the content of other substances A in raw material composition A should be appropriately adjusted so that boron (B) becomes the main atom among the constituent atoms other than silicon (Si) and oxygen (O) in the amorphous aluminosilicate produced.

[0046] The mixing of raw material composition A should be done in such a way that the individual raw materials contained in raw material composition A are not unevenly distributed (i.e., mixed uniformly), and there are no particular limitations on the method and conditions for this mixing. Specific mixing conditions can be exemplified by mixing at a temperature of 10°C to 60°C for 0.5 hours to 6 hours, and preferably at a temperature of 15°C to 40°C for 1 hour to 2 hours.

[0047] The amorphous borosilicate obtained by mixing raw material composition A may be used directly in the boron substitution process, or it may be used in the boron substitution process after undergoing at least one of the following treatments: washing and drying.

[0048] The washing process is a procedure for washing amorphous borosilicate. The washing method is arbitrary, but one example is to bring the amorphous borosilicate into contact with a sufficient amount of pure water.

[0049] The drying process removes moisture physically adsorbed onto the amorphous borosilicate. While the drying method is arbitrary, one example is to treat the amorphous borosilicate in an air atmosphere at a temperature between 50°C and 250°C for 1 to 120 hours.

[0050] In the boron substitution process, boron (B) contained in amorphous borosilicate is replaced with aluminum (Al). The substitution of boron (B) with aluminum (Al) may involve replacing all of the boron (B) contained in amorphous borosilicate with aluminum (Al), or, if amorphous aluminosilicate can be obtained (if the Al / X1 molar ratio exceeds 1), all of the boron contained in amorphous borosilicate may be replaced with aluminum, some of the boron (B) contained in amorphous borosilicate may be replaced with aluminum (Al) while the remaining boron is maintained, or some of the boron contained in amorphous borosilicate may be replaced with aluminum (Al) while the remaining boron is removed.

[0051] The method for replacing boron (B) contained in amorphous borosilicate with aluminum (Al) can be any conventionally known replacement method and is not particularly limited, but a treatment in which amorphous borosilicate is brought into contact with an aqueous solution of aluminum salt (hereinafter also referred to as "contact treatment") can be used. When amorphous borosilicate is brought into contact with an aqueous solution of aluminum salt, the boron (B) contained in the amorphous borosilicate is released, and aluminum (Al) is inserted in the place where the boron (B) was released, and the boron (B) is replaced by aluminum (Al).

[0052] The aluminum salt aqueous solution used in the contact treatment is an aqueous solution containing an aluminum salt. Examples of aluminum salts included in the aluminum salt aqueous solution include at least one selected from the group consisting of aluminum sulfate, aluminum chloride, and aluminum nitrate. It is preferable that it be at least one of aluminum nitrate and aluminum sulfate, and more preferably aluminum nitrate, because boron (B) contained in amorphous borosilicate is easily replaced by aluminum (Al).

[0053] In contact treatment, the higher the aluminum concentration in the aluminum salt aqueous solution, the easier it is for boron (B) in amorphous borosilicate to be replaced with aluminum (Al). Considering these characteristics, it is preferable to appropriately adjust the aluminum concentration in the aluminum salt aqueous solution so that amorphous aluminosilicate can be obtained (so that the Al / X1 molar ratio exceeds 1). From the viewpoint of making it easier to produce amorphous aluminosilicate with a Raman intensity ratio I2 / I1 of 4.0 or higher, the aluminum concentration in the aluminum salt aqueous solution is preferably 0.1 mol / L or higher, 0.2 mol / L or higher, or 0.4 mol / L or higher, and preferably 3 mol / L or lower, 2.5 mol / L or lower, or 2 mol / L or lower. While the aforementioned combinations of upper and lower limits for aluminum concentration are arbitrary, from the viewpoint of facilitating the production of amorphous aluminosilicate with a Raman intensity ratio I2 / I1 of 4.0 or higher, it is preferable that the concentration be between 0.1 mol / L and 3 mol / L, more preferably between 0.2 mol / L and 2.5 mol / L, and even more preferably between 0.4 mol / L and 2 mol / L.

[0054] In contact treatment, the greater the amount of aluminum salt aqueous solution that comes into contact with the amorphous borosilicate, the more likely it is that boron (B) in the amorphous borosilicate will be replaced with aluminum (Al). Considering these characteristics, it is preferable to appropriately adjust the amount of aluminum salt aqueous solution that comes into contact with the amorphous borosilicate so that amorphous aluminosilicate can be obtained (so that the Al / X1 molar ratio exceeds 1). From the viewpoint of making it easier to produce amorphous aluminosilicate with a Raman intensity ratio I2 / I1 of 4.0 or higher, it is preferable that the amount of aluminum salt aqueous solution that comes into contact with the amorphous borosilicate is 1 part by mass or more, 3 parts by mass or more, or 5 parts by mass or more, and preferably 30 parts by mass or less, 25 parts by mass or less, or 20 parts by mass or less, per 1 part by mass of amorphous borosilicate. While the combination of contact amounts of the aforementioned aluminum salt aqueous solution is arbitrary, from the viewpoint of making it easier to produce amorphous aluminosilicate with a Raman intensity ratio I2 / I1 of 4.0 or higher, it is preferable that the amount is 1 to 30 parts by mass, more preferably 3 to 25 parts by mass, and even more preferably 5 to 20 parts by mass per 1 part by mass of amorphous borosilicate.

[0055] The method of contacting amorphous borosilicate with an aqueous aluminum salt solution in the contact treatment is not particularly limited, and for example, a method of mixing the aqueous aluminum salt solution with amorphous borosilicate can be used.

[0056] The contact conditions between amorphous borosilicate and aluminum salt aqueous solution during the contact treatment can be adjusted as appropriate to obtain amorphous aluminosilicate (so that the Al / X1 molar ratio exceeds 1). However, the higher the temperature at which amorphous borosilicate and aluminum salt aqueous solution come into contact (hereinafter also referred to as "contact temperature"), the more easily the boron (B) in amorphous borosilicate is replaced by aluminum (Al). Similarly, the longer the contact time between amorphous borosilicate and aluminum salt aqueous solution (hereinafter also referred to as "contact time"), the more easily the boron (B) in amorphous borosilicate is replaced by aluminum (Al). Therefore, it is preferable to adjust the contact temperature and contact time during the contact treatment as appropriate, taking these characteristics into consideration, so that amorphous aluminosilicate is obtained (so that the Al / X1 molar ratio exceeds 1).

[0057] From the viewpoint of facilitating the production of amorphous aluminosilicate with a Raman intensity ratio I2 / I1 of 4.0 or higher, the contact temperature in the contact treatment is preferably 5°C or higher, 10°C or higher, 15°C or higher, or 50°C or higher, and preferably 120°C or lower, 110°C or lower, or 100°C or lower. The combination of the upper and lower limits of the contact temperature as described above is arbitrary, but from the viewpoint of facilitating the production of amorphous aluminosilicate with a Raman intensity ratio I2 / I1 of 4.0 or higher, the contact temperature in the contact treatment is preferably 5°C or higher and 120°C or lower, more preferably 10°C or higher and 110°C or lower, even more preferably 15°C or higher and 100°C or lower, and particularly preferably 50°C or higher and 100°C or lower.

[0058] From the viewpoint of facilitating the production of amorphous aluminosilicate with a Raman intensity ratio I2 / I1 of 4.0 or higher, the contact time in the contact treatment is preferably 0.1 hours or more, 0.2 hours or more, 0.5 hours or more, or 10 hours or more. The upper limit of the contact time is not particularly limited and can be, for example, 48 hours or less, or 24 hours or less. The combination of the upper and lower limits of the contact time as described above is arbitrary, but from the viewpoint of facilitating the production of amorphous aluminosilicate with a Raman intensity ratio I2 / I1 of 4.0 or higher, the contact time in the contact treatment is preferably 0.1 hours or more and 48 hours or less, more preferably 0.2 hours or more and 48 hours or less, even more preferably 0.5 hours or more and 24 hours or less, and particularly preferably 10 hours or more and 24 hours or less.

[0059] Through the contact treatment described above, boron (B) contained in amorphous borosilicate is replaced with aluminum (Al), and amorphous aluminosilicate with a Raman intensity ratio I2 / I1 of 4.0 or higher can be obtained. The obtained amorphous aluminosilicate may be used as is as the amorphous aluminosilicate of this embodiment, or it may be used as the amorphous aluminosilicate of this embodiment after undergoing at least one of the washing and drying treatments. The washing and drying treatments that can be performed on amorphous aluminosilicate are the same as those that can be performed on amorphous borosilicate used as a raw material for the amorphous aluminosilicate, so a detailed explanation is omitted.

[0060] The amorphous aluminosilicate of this embodiment can be produced by the manufacturing method including the boron substitution step described above. The amorphous aluminosilicate of this embodiment has a Raman intensity ratio I2 / I1 of 4.0 or higher and a structure rich in 4-membered ring units. Therefore, by using it as a starting material (alumina source and silica source) for CHA-type zeolite, the crystallization of CHA-type zeolite is promoted without using SDA, and CHA-type zeolite can be produced. Furthermore, since the crystallization of CHA-type zeolite is promoted using the amorphous aluminosilicate of this embodiment, the yield of CHA-type zeolite can also be improved. On the other hand, amorphous aluminosilicate produced directly from starting materials such as alumina sources and silica sources (amorphous aluminosilicate that is not produced from amorphous borosilicate) has a Raman intensity ratio I2 / I1 of less than 4.0 and a structure poor in 4-membered ring units, as shown in Comparative Example 1 described later. Therefore, when using amorphous aluminosilicates directly produced from starting materials such as alumina sources or silica sources (amorphous aluminosilicates that are not produced from amorphous borosilicates), or substances other than amorphous aluminosilicates that do not contain 4-membered ring units, as starting materials (silica sources and alumina sources), the crystallization of CHA-type zeolite is not easily promoted, and if SDA is not used, CHA-type zeolite may not crystallize at all, or even if it does crystallize, the yield of CHA-type zeolite will decrease.

[0061] Next, a method for producing CHA-type zeolite using the amorphous aluminosilicate of this embodiment (hereinafter also referred to as "the method for producing CHA-type zeolite according to this embodiment") will be described. In the following, a method for producing CHA-type zeolite without using SDA (SDA-free synthesis method) will be described, but the amorphous aluminosilicate of this embodiment may be used not only in the method for producing CHA-type zeolite without SDA, but also in the method for producing CHA-type zeolite using SDA.

[0062] The method for producing CHA-type zeolite according to this embodiment includes a crystallization step of crystallizing a raw material composition (hereinafter also referred to as "raw material composition B") comprising amorphous aluminosilicate, an alkali source, and water according to this embodiment.

[0063] The amorphous aluminosilicate of this embodiment contained in raw material composition B contains aluminum (Al) and silicon (Si), and therefore functions as an alumina source and a silica source. The alumina source and silica source contained in raw material composition B may consist only of the amorphous aluminosilicate of this embodiment, or it may further contain at least one of other alumina sources and silica sources (hereinafter also referred to as "secondary alumina source" and "secondary silica source," respectively) as needed. However, from the viewpoint of further improving the yield of CHA-type zeolite, it is preferable that raw material composition B substantially does not contain secondary alumina sources and secondary silica sources (i.e., the alumina source and silica source in raw material composition B consists only of the amorphous aluminosilicate of this embodiment).

[0064] The secondary alumina source is a compound containing aluminum (Al), and examples include one or more selected from the group consisting of aluminum isopropoxide, aluminum sulfate, aluminum nitrate, aluminum chloride, aluminum hydroxide, metallic aluminum, pseudoboehmite, alumina sol, and aluminosilicate gel. When raw material composition B contains a secondary alumina source, the content of the secondary alumina source can be appropriately set within a range that achieves the effects of the present invention.

[0065] The secondary silica source is a compound containing silicon (Si), and examples include one or more selected from the group consisting of silica sol, fumed silica, colloidal silica, precipitated silica, sodium silicate, amorphous silica, and aluminosilicate gel. When raw material composition B contains a secondary silica source, the content of the secondary silica source can be appropriately set within a range that achieves the effects of the present invention.

[0066] The alkali source contained in raw material composition B is a compound containing an alkali metal element, and includes at least one of alkali metal element hydroxides and halides, with alkali metal element hydroxides being preferred. Examples of alkali metal elements include one or more selected from the group consisting of sodium, potassium, rubidium, and cesium, with at least one of sodium and potassium being preferred, and both sodium and potassium being more preferred.

[0067] The water contained in raw material composition B may be one or more selected from the group consisting of distilled water, deionized water, and pure water. The water contained in raw material composition B may also be water derived from other starting materials, such as water included as a solvent or structured water.

[0068] The composition of raw material composition B can be appropriately set considering the composition of the CHA-type zeolite to be produced, but from the viewpoint of further improving the yield of CHA-type zeolite, the following composition is preferable. In the following composition, the M / SiO2 molar ratio represents the molar ratio of alkali metal elements to silica. If raw material composition B contains two or more alkali metal elements, the total number of moles of alkali metal elements should be used for M (number of moles of alkali metal elements) in the M / SiO2 molar ratio. SiO2 / Al2O3 molar ratio = 12 or greater, 13 or greater, or 14 or greater, 40 or younger, 35 or younger, or 30 or younger M / SiO2 molar ratio = 0.4 or higher, 0.45 or higher, or 0.5 or higher, 1.4 or less, 1.2 or less, or 1 or less H2O / SiO2 molar ratio = 10 or more, 20 or more, or 30 or more, and 150 or less, 130 or less, or 110 or less OH - / SiO2 molar ratio = 0.4 or higher, 0.45 or higher, or 0.5 or higher, 1.4 or less, 1.2 or less, or 1 or less

[0069] A more preferred composition of raw material composition B is shown below. SiO2 / Al2O3 molar ratio = 12 to 40 More preferably, 14 to 30 M / SiO2 molar ratio = 0.4 or greater and 1.4 or less More preferably, 0.5 or more and 1 or less H2O / SiO2 molar ratio = 10 to 150 More preferably, 30 to 110 OH - / SiO2 molar ratio = 0.4 to 1.4 More preferably, 0.5 or more and 1 or less

[0070] The raw material composition B may consist only of the amorphous aluminosilicate, alkali source, and water of this embodiment, or it may further contain other substances (hereinafter also referred to as "other substance B"). Examples of other substance B include one or more selected from the group of secondary alumina sources and secondary silica sources, and boron sources described above. The boron source that may be included in the raw material composition B is a substance containing boron, for example, the boron that may be included in the amorphous aluminosilicate of this embodiment.

[0071] The raw material composition B may contain other substances B, such as a boron source, but from the viewpoint of further improving the yield of CHA-type zeolite, it is preferable that it substantially does not contain other substances B, such as a boron source. If the raw material composition B contains other substances B, the content of other substances B in the raw material composition B should be adjusted appropriately so that CHA-type zeolite is produced.

[0072] In the crystallization step, raw material composition B is crystallized. The crystallization of raw material composition B may be carried out in the presence of seed crystals. From the viewpoint of further improving the yield of CHA-type zeolite, the ratio of the total mass of silicon (Si) and aluminum (Al) in the seed crystals (converted to silica (SiO2) and alumina (Al2O3), respectively, to the total mass of silicon (Si) and aluminum (Al) in raw material composition B (without seed crystals) (hereinafter also referred to as "seed crystal content") is preferably 0.5% by mass or more and 20% by mass or less, more preferably 0.8% by mass or more and 16% by mass or less, and even more preferably 1% by mass or more and 12% by mass or less.

[0073] The seed crystal can be any zeolite having a microstructure (composite building unit (CBU)) in its skeletal structure that is common to CHA-type zeolite. For example, it is preferable that it contains at least one zeolite selected from the group consisting of CHA-type zeolite, FAU-type zeolite, AEI-type zeolite, EMT-type zeolite, LEV-type zeolite, AFX-type zeolite, and GME-type zeolite, and it is more preferable that it is CHA-type zeolite.

[0074] The crystallization of raw material composition B is not limited to any particular method, as long as it can be crystallized in a way that yields CHA-type zeolite. A preferred crystallization method is hydrothermal treatment of raw material composition B. Hydrothermal treatment can be performed by placing raw material composition B in a sealed pressure vessel and heating it. Examples of hydrothermal treatment conditions include the following: Processing temperature: 140°C or higher or 150°C or higher, 200℃ or below or 190℃ or below Processing time: 1 hour or more or 4 hours or more, 48 hours or less or 36 hours or less Processing pressure: Self-generating pressure

[0075] CHA-type zeolite can be produced by the manufacturing method including the crystallization step described above. The CHA-type zeolite obtained in the crystallization step may be used as is for the intended purpose, or it may be used after undergoing at least one of the washing and drying processes. The washing and drying processes that can be performed on the CHA-type zeolite are the same as those that can be performed on amorphous aluminosilicate, which is the starting material for the CHA-type zeolite, so a detailed explanation is omitted.

[0076] The physical properties of the CHA-type zeolite obtained by the method for producing CHA-type zeolite according to this embodiment (hereinafter also referred to as "CHA-type zeolite according to this embodiment") are arbitrary, but it is preferable that the CHA-type zeolite has at least one of the following physical properties, and it is more preferable that the CHA-type aluminosilicate has at least one of the following physical properties. SiO2 / Al2O3 molar ratio: 4 or more, or 5 or more, 15 or younger, or 12 or younger, BET specific surface area: 200m 2 / g or more, or 250m 2 / g or more, 800m 2 / g or less, or 700m 2 / g or less Micropore volume: 0.05 mL / g or more, or 0.08 mL / g or more, 0.3mL / g or less, or 0.25mL / g or less

[0077] The BET specific surface area of ​​the CHA-type zeolite according to this embodiment can be determined by a multi-point BET method using a general specific surface area measuring device (for example, device name: autosorb-iQ, manufactured by Anton Paar Japan Co., Ltd.) and a nitrogen adsorption method (adsorbing gas: nitrogen, measurement temperature: -196°C) in accordance with JIS Z 8830:2013. For the zeolite (measurement sample) to be measured for BET specific surface area, a zeolite pre-treated at 350°C for 5 hours in a vacuum atmosphere (10 Pa or less) can be used.

[0078] Furthermore, the micropore volume of the CHA-type zeolite according to this embodiment can be determined by a t-plot method using a general specific surface area measuring device (for example, device name: autosorb-iQ, manufactured by Anton Paar Japan Co., Ltd.) and a nitrogen adsorption method (adsorbing gas: nitrogen, measurement temperature: -196°C) in accordance with JIS Z 8830:2013. For the zeolite (measurement sample) to be measured for BET specific surface area, a zeolite pre-treated at 350°C for 5 hours in a vacuum atmosphere (10 Pa or less) can be used. [Examples]

[0079] The present disclosure will be described in more detail below with reference to examples. However, the present disclosure is not limited to these examples.

[0080] (XRD pattern) XRD measurements of the product were performed using a standard X-ray diffractometer (product name: Ultima-IV, manufactured by Rigaku Corporation). The measurement conditions were as follows: Acceleration current / voltage: 40mA / 40kV Radiation source: CuKα radiation (λ=1.5405Å) Measurement mode: Step scan Scanning conditions: 10° / min Measurement range: 2θ = 3° to 50° Divergence vertical limiting slit: 10mm Divergence / Induction Slit: 1° Scattering slit: 1° Light-receiving slit: 0.30mm Detector: Semiconductor detector (D / teX Ultra2) Filter: Not used

[0081] The obtained XRD patterns were analyzed using the analysis program included with the measurement device (product name: SmartLab StudioII, manufactured by Rigaku Corporation) to correct the baseline, and then the corrected XRD peaks were detected and their intensity analyzed. The corrected XRD patterns were compared with the reference patterns to identify the crystal structure.

[0082] In the examples and comparative examples shown below, a crystalline substance (crystalline aluminosilicate) was determined to be a crystalline material when a crystalline XRD peak (a peak whose peak top 2θ is identified and detected by the analysis of the XRD pattern described above) was confirmed in the obtained XRD pattern, and an amorphous material (amorphous aluminosilicate or amorphous borosilicate) was determined to be an amorphous material when a crystalline XRD peak (a peak whose peak top 2θ is identified and detected by the analysis of the XRD pattern described above) was not confirmed in the obtained XRD pattern. In the analysis of the XRD pattern described above, the peak top 2θ was identified and detected for peaks with a full width at half maximum (FMAX) of 2θ = 0.50° or less.

[0083] (composition analysis) For compositional analysis, a sample solution was prepared by dissolving the sample in an aqueous hydrofluoric acid solution. The sample solution was then measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES) using a standard ICP instrument (instrument name: ICPE-9820, manufactured by Shimadzu Corporation).

[0084] (UV-Raman) UV-Raman spectroscopy was performed using a micro-laser Raman spectrometer (instrument name: LabRAM HR Evolution, Horiba, Ltd.). The sample was divided onto a glass slide, and measurements were taken with a laser wavelength of 325 nm, laser power of 6 mW, exposure time of 300 seconds, and two integrations. 750-850 The maximum intensity I1 is based on the minimum intensity of 200-900 nm as the baseline, and this is used as B 750-850 It was obtained by subtracting it from the maximum intensity measurement. Similarly, B 400-550 The maximum intensity I2 is based on the minimum intensity of 200-900 nm as the baseline, and this is used as B 400-550 It was determined by subtracting it from the maximum intensity measurement. The Raman intensity ratio I2 / I1 was calculated from the obtained maximum intensities I1 and I2. Note that B 750-850 and B 400-550The full width at half maximum (FMAX) was determined by using the minimum intensity in the range from 200 nm to 900 nm as the baseline, finding the maximum value of the band, and measuring the band width at half the intensity of the found maximum value.

[0085] (Yield of CHA-type zeolite) The yield of CHA-type zeolite was calculated using the following formula (1). Yield (%) = (W CHA / W raw ) × 100 ···(1) In the above equation (1), W CHA This is the total mass (g) of Si and Al contained in the CHA-type zeolite when converted to SiO2 and Al2O3, respectively. raw This is the total mass (g) of Si and Al contained in the raw material composition when converted to SiO2 and Al2O3, respectively.

[0086] (BET specific surface area and micropore volume) The BET specific surface area was determined by the BET multipoint method using nitrogen adsorption in accordance with JIS Z 8830:2013, and the micropore volume was determined by the t-plot method using nitrogen adsorption in accordance with JIS Z 8830:2013. The nitrogen adsorption test to determine the BET specific surface area and micropore volume was performed using a general specific surface area measuring device (device name: autosorb-iQ, manufactured by Anton Paar Japan Co., Ltd.) with nitrogen as the adsorption gas and a measurement temperature of -196°C. The sample used for measurement was a CHA-type zeolite that had been pretreated by holding it at 350°C for 5 hours in a vacuum atmosphere (10 Pa or less).

[0087] (SEM observation) SEM observations were performed using a standard scanning electron microscope (device name: JSM-IT800, manufactured by JEOL Ltd.) under the following conditions. Acceleration voltage: 5kV Magnification: 30,000±5,000x

[0088] (Synthesis of amorphous borosilicate) Example 1 5.0 g of sodium silicate (manufactured by Wako Pure Chemical Industries, Ltd.) was used as the silica source and sodium source, and 40.62 g of a 3.5% by mass boric acid aqueous solution was used as the boron source to obtain raw material composition A having the following composition. B2O3 / Na2O molar ratio = 1.5 NaOH / Si molar ratio = 0.6 H2O / Si molar ratio = 92.9

[0089] The raw material composition A was stirred at room temperature (25°C) at 500 rpm for 1 hour, and then solid-liquid separation was performed. The separated solid was washed with pure water and dried in an air atmosphere at 100°C for 24 hours to obtain a gel-like amorphous borosilicate.

[0090] The obtained amorphous borosilicate had an SiO2 / B2O3 molar ratio of 1.8 and exhibited the XRD pattern shown in Figure 1 (see the precursor in Example 1 in Figure 1). As shown in Figure 1, no crystalline XRD peaks (peaks where the peak top 2θ is identified and detected) were observed in the XRD pattern of the obtained amorphous borosilicate.

[0091] The amorphous borosilicate was mixed with a 1.0 N aluminum nitrate aqueous solution in an amount 10 times the mass of the amorphous borosilicate, and the mixture was allowed to stand at 90°C for 24 hours to replace the boron contained in the amorphous borosilicate with aluminum. The substituted amorphous borosilicate (amorphous aluminosilicate) was washed with pure water and then dried in an air atmosphere at 100°C for 24 hours to obtain the amorphous aluminosilicate of this example.

[0092] The amorphous aluminosilicate of this example had an SiO2 / Al2O3 molar ratio of 14.4 and an SiO2 / B2O3 molar ratio of ∞, and had the XRD pattern shown in Figure 1 (see Example 1 in Figure 1). As shown in Figure 1, no crystalline XRD peaks (peaks where the 2θ of the peak top is identified and detected) were observed in the XRD pattern of the amorphous aluminosilicate of this example. The UV-Raman spectrum of the amorphous aluminosilicate of this example is shown in Figure 2. In the UV-Raman spectrum, B 750-850B relative to the maximum intensity I1 400-550 The ratio of the maximum intensity I2 to the intensity (Raman intensity ratio I2 / I1) was 5.89. Also, B 750-850 The half-width is 64cm -1 B 400-550 The half-width is 158cm -1 In this specification, an SiO2 / B2O3 molar ratio of ∞ means that it is substantially free of boron.

[0093] Example 2 10.0 g of sodium silicate (manufactured by Wako Pure Chemical Industries, Ltd.) was used as the silica source and sodium source, and 27.1 g of a 3.5% by mass boric acid aqueous solution was mixed as the boron source to obtain raw material composition A having the following composition. Amorphous borosilicate was obtained in the same manner as in Example 1, except that the obtained raw material composition A was used instead of the raw material composition A used in Example 1. B2O3 / Na2O molar ratio = 1.0 NaOH / Si molar ratio = 0.6 H2O / Si molar ratio = 35.4

[0094] The obtained amorphous borosilicate had an SiO2 / B2O3 molar ratio of 3.4 and exhibited the XRD pattern shown in Figure 1 (see the precursor in Example 2 in Figure 1). As shown in Figure 1, no crystalline XRD peaks (peaks where the 2θ peak top is identified and detected) were observed in the XRD pattern of the obtained amorphous borosilicate.

[0095] Except for using the amorphous borosilicate obtained in place of the amorphous borosilicate used in Example 1, the boron contained in the amorphous borosilicate was replaced with aluminum using the same method as in Example 1. The substituted amorphous borosilicate (amorphous aluminosilicate) was then washed and dried to obtain the amorphous aluminosilicate of this example.

[0096] The amorphous aluminosilicate of this example had an SiO2 / Al2O3 molar ratio of 14.5 and an SiO2 / B2O3 molar ratio of ∞, and had the XRD pattern shown in Figure 1 (see Example 2 in Figure 1). As shown in Figure 1, no crystalline XRD peaks (peaks where the 2θ of the peak top is identified and detected) were observed in the XRD pattern of the amorphous aluminosilicate of this example. The UV-Raman spectrum of the amorphous aluminosilicate of this example is shown in Figure 2. The Raman intensity ratio I2 / I1 of the amorphous aluminosilicate of this example was 4.19. 750-850 The half-width is 66cm -1 B 400-550 The half-width is 149cm -1 That was the case.

[0097] Comparative Example 1 Based on the description in Example 1 of Japanese Patent Application Publication No. 2022-162229, an amorphous aluminosilicate for this comparative example was obtained. Specifically, 5.0 g of colloidal silica (Ludox-HS40) as the silica source, 3.4 g of sodium aluminate as the aluminum source and sodium source, 2.5 g of sodium hydroxide as the sodium source, and 32.4 g of water were mixed to obtain raw material composition A having the following composition. SiO2 / Al2O3 molar ratio = 10.0 Na / SiO2 molar ratio = 0.6 H2O / SiO2 molar ratio = 15

[0098] The raw material composition A was stirred at 500 rpm for 1 hour at room temperature, and then solid-liquid separation was performed. The separated solid was washed with 0.1 N sulfuric acid and dried in an air atmosphere at 100°C for 24 hours to obtain a gel-like amorphous aluminosilicate. 0.8 N sulfuric acid was added to this amorphous aluminosilicate in a mass ratio of 9, and the mixture was stirred at room temperature for 3 hours. After that, solid-liquid separation was performed, the mixture was washed with pure water, and dried in an air atmosphere at 100°C for 24 hours to obtain the amorphous aluminosilicate of this comparative example.

[0099] The amorphous aluminosilicate in this comparative example had an SiO2 / Al2O3 ratio of 11.0 and possessed the XRD pattern shown in Figure 1 (see Comparative Example 1 in Figure 1). As shown in Figure 1, no crystalline XRD peaks (peaks where the peak top 2θ is identified and detected) were observed in the XRD pattern of the amorphous aluminosilicate in this comparative example. The Raman intensity ratio I2 / I1 of the amorphous aluminosilicate in this comparative example was 3.63. Also, B 750-850 The half-width is 59cm -1 B 400-550 The half-width is 197cm -1 That was the case.

[0100] (Synthesis of CHA-type zeolite) Example 3 The amorphous aluminosilicate from Example 1, sodium hydroxide, potassium hydroxide, and pure water were mixed to obtain raw material composition B having the following molar composition. SiO2 / Al2O3 molar ratio = 14.4 SiO2 / B2O3 molar ratio = ∞ Na / SiO2 molar ratio = 0.45 K / SiO2 molar ratio = 0.15 H2O / SiO2 molar ratio = 100.0 OH - / SiO2 molar ratio = 0.60

[0101] CHA-type zeolite was mixed with raw material composition B so that the seed crystal content was 10% by mass, and then sealed in a 23 ml autoclave. The raw material composition B in the autoclave was hydrothermally treated at 170°C for 20 hours with stirring at 20 rpm and under autocoagulation pressure to crystallize and obtain a crystalline product.

[0102] The obtained crystals were filtered and washed, and dried overnight at 80°C in an air atmosphere to obtain the product. The obtained product had an SiO2 / Al2O3 molar ratio of 7.0, an SiO2 / B2O3 molar ratio of ∞, and a BET specific surface area of ​​612 m². 2The CHA-type zeolite (crystalline aluminosilicate) had a micropore volume of 0.24 mL / g and a yield of 49.9%. The XRD pattern of the CHA-type zeolite in this example is shown in Figure 3, and the SEM observation is shown in Figure 4.

[0103] Example 4 The amorphous aluminosilicate from Example 2, sodium hydroxide, potassium hydroxide, and pure water were mixed to obtain raw material composition B having the following molar composition. SiO2 / Al2O3 molar ratio = 14.5 SiO2 / B2O3 molar ratio = ∞ Na / SiO2 molar ratio = 0.45 K / SiO2 molar ratio = 0.15 H2O / SiO2 molar ratio = 100.0 OH - / SiO2 molar ratio = 0.60

[0104] The product was obtained in the same manner as in Example 3, except that the obtained raw material composition B was used instead of the raw material composition B used in Example 3. The obtained product had an SiO2 / Al2O3 molar ratio of 6.7, an SiO2 / B2O3 molar ratio of ∞, and a BET specific surface area of ​​589 m². 2 The CHA-type zeolite (crystalline aluminosilicate) had a micropore volume of 0.23 mL / g and a yield of 55.2%. The XRD pattern of the CHA-type zeolite in this example is shown in Figure 3, and the SEM observation is shown in Figure 4.

[0105] Comparative Example 2 The product of this comparative example was obtained in the same manner as in Example 3, except that the amorphous aluminosilicate of Comparative Example 1 was used instead of the amorphous aluminosilicate of Example 1. The raw material composition B of this comparative example had the following composition. SiO2 / Al2O3 molar ratio = 11.0 SiO2 / B2O3 molar ratio = ∞ Na / SiO2 molar ratio = 0.45 K / SiO2 molar ratio = 0.15 H2O / SiO2 molar ratio = 100.0 OH- / SiO2 molar ratio = 0.60

[0106] The resulting product was amorphous; no zeolite was obtained.

[0107] Comparative Example 3 The product was obtained in the same manner as in Example 3, except that the amorphous aluminosilicate of Comparative Example 1 was used instead of the amorphous aluminosilicate of Example 1, and the content of each raw material was changed to obtain the following molar composition of raw material composition B. SiO2 / Al2O3 molar ratio = 11.0 Na / SiO2 molar ratio = 0.525 K / SiO2 molar ratio = 0.175 H2O / SiO2 molar ratio = 100.0 OH - / SiO2 molar ratio = 0.70

[0108] The resulting product had an SiO2 / Al2O3 molar ratio of 6.9 and a BET specific surface area of ​​524 m². 2 The CHA-type zeolite (crystalline aluminosilicate) had a pore size of 0.21 mL / g, a micropore volume of 0.21 mL / g, and a yield of 35.6%. The XRD pattern of the CHA-type zeolite used in this comparative example is shown in Figure 3.

[0109] Comparative Example 4 The product of this comparative example was obtained in the same manner as in Example 3, except that colloidal silica and sodium aluminate were used instead of amorphous aluminosilicate in Example 1, and the content of the raw materials was changed to obtain the following molar composition of raw material composition B. SiO2 / Al2O3 molar ratio = 10.0 Na / SiO2 molar ratio = 0.525 K / SiO2 molar ratio = 0.175 H2O / SiO2 molar ratio = 100.0 OH - / SiO2 molar ratio = 0.70

[0110] The resulting product was amorphous; no zeolite was obtained.

[0111] As described above, by using the amorphous aluminosilicate obtained by substituting boron (B) in amorphous borosilicate with aluminum (Al) (amorphous aluminosilicate with a Raman intensity ratio I2 / I1 of 4.0 or higher) as a starting material (alumina source and silica source) for CHA-type zeolite, it was confirmed that CHA-type zeolite can be produced in high yield without using SDA.

Claims

1. Amorphous aluminosilicate for manufacturing CHA-type zeolite, In the UV-Raman spectrum, wavenumbers 750–850 cm⁻¹ －１ Maximum intensity of the band I １ For wavenumbers of 400-550 cm －１ Maximum intensity of the band I ２ Amorphous aluminosilicate having a strength ratio of 4.0 or higher.

2. The amorphous aluminosilicate according to claim 1, wherein the molar ratio of silica to alumina is 5 or more and 20 or less.

3. A method for producing amorphous aluminosilicate according to claim 1 or 2, comprising the step of substituting boron atoms contained in amorphous borosilicate with aluminum atoms.

4. A method for producing a CHA-type zeolite, comprising the step of crystallizing a composition comprising amorphous aluminosilicate, an alkali source, and water as described in claim 1 or 2.

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