WO2014038636A1

WO2014038636A1 - Silicoaluminophosphate salt and nitrogen oxide reduction catalyst using same

Info

Publication number: WO2014038636A1
Application number: PCT/JP2013/073975
Authority: WO
Inventors: 岡庭　宏; 敬助徳永; 良和永井; 英和青山; 平野　茂; 満明吉光
Original assignee: 東ソー株式会社
Priority date: 2012-09-07
Filing date: 2013-09-05
Publication date: 2014-03-13

Abstract

Provided is a silicoaluminophosphate salt for which deterioration of the nitrogen oxide reduction rate is low even when exposed to an atmosphere containing moisture. A silicoaluminophosphate salt which comprises at least one type of metal selected from the group consisting of group VIIIB elements, group IB elements and group VIIB elements of the Periodic Table, and has a CHA structure and an AEI structure, the ratio of the AEI structure exceeding 50%. In this silicoaluminophosphate salt, the at least one type of metal from group VIIIB elements and group IB elements of the Periodic Table is preferably copper.

Description

Silicoaluminophosphate and nitrogen oxide reduction catalyst using the same

The present invention relates to a silicoaluminophosphate having a CHA structure and an AEI structure. More specifically, the present invention relates to a silicoaluminophosphate having a metal-containing CHA structure and an AEI structure suitable for a nitrogen oxide reduction catalyst.

As a silicoaluminophosphate having two types of skeletal structures, a continuous crystal in which part of the CHA structure of SAPO-34 and part of the AEI structure of SAPO-18 is laminated has been reported (for example, Patent Document 1). .
Further, it has been reported that such a continuous crystal can be used as a nitrogen oxide purification catalyst (Patent Document 2). For example, Patent Literature 2 reports that a metal is contained in silicoaluminophosphate having a ratio of CHA structure to AEI structure of 90:10 and used as a nitrogen oxide reduction catalyst.

Japanese National Table 2004-524252 WO2011-112949 Publication

When the nitrogen oxide reduction catalyst comprising a silicoaluminophosphate continuous crystal disclosed in Patent Document 2 is exposed to an atmosphere containing moisture, the crystallinity of the catalyst decreases with time. In addition, the nitrogen oxide reduction catalyst has a solid acid amount that decreases with a decrease in crystallinity due to hydration. As a result, the conventional nitrogen oxide reduction catalyst composed of a continuous crystal of silicoaluminophosphate has a problem that the nitrogen oxide reduction rate is remarkably reduced during storage and use.
The present invention is to solve these problems and to provide a silicoaluminophosphate that has a low reduction in nitrogen oxide reduction rate even when exposed to an atmosphere containing moisture.

In view of the above problems, the present inventors have intensively studied. As a result, the silicoaluminophosphate containing a CHA structure and an AEI structure and containing a large amount of the AEI structure contains a metal, which reduces the reduction rate of nitrogen oxides even when exposed to an atmosphere containing moisture. As a result, the present invention has been completed.
That is, the gist of the present invention is the following [1] to [5].

[1] Silicoaluminum having a CHA structure and an AEI structure, having at least one metal selected from the group of Group VIIIB elements, Group IB elements, and Group VIIB elements of the periodic table, and the proportion of the AEI structure exceeds 50% Norphosphate.
[2] The silicoaluminophosphate according to the above [1], wherein at least one metal selected from the group of Group VIIIB elements, Group IB elements and Group VIIB elements of the periodic table is copper.
[3] A crystallization step of crystallizing a mixture containing a tertiary amine, a silicoaluminophosphate having a CHA structure and an AEI structure obtained by the crystallization step, and the proportion of the AEI structure exceeds 50% The method for producing a silicoaluminophosphate according to the above [1] or [2], comprising a metal-containing step of incorporating a metal into the silicoaluminophosphate.
[4] A method for producing a nitrogen oxide reduction catalyst using the silicoaluminophosphate according to [1] or [2].
[5] A method for reducing a nitrogen oxide, comprising using the silicoaluminophosphate according to [1] or [2].

According to the present invention, it is possible to provide a silicoaluminophosphate that is less likely to decrease the nitrogen oxide reduction rate even when exposed to an atmosphere containing moisture.
Furthermore, the continuous crystal silicoaluminophosphate of the present invention provides a nitrogen oxide reduction catalyst that causes little reduction in the nitrogen oxide reduction rate even when exposed to an atmosphere containing moisture, and a nitrogen oxide reduction method using the same. Can be provided. In particular, the continuous crystal silicoaluminophosphate of the present invention has a nitrogen oxide reduction rate at a low temperature of less than 500 ° C., further 200 ° C. or less, or even 150 ° C. or less even when exposed to an atmosphere containing moisture. A nitrogen oxide reduction catalyst with little decrease can be provided. Therefore, the intergrowth silicoaluminophosphate of the present invention and the nitrogen oxide reduction catalyst using the same have little deterioration in nitrogen oxide reduction characteristics even after being exposed to moisture-containing atmosphere, so-called water resistance. Can be a high nitrogen oxide reduction catalyst.
Furthermore, the production method of the present invention can provide a method for producing silicoaluminophosphate with little reduction in nitrogen oxide reduction rate even when exposed to an atmosphere containing moisture.
Furthermore, the present adsorbent / desorbent has a high water vapor adsorption amount, and can be used for a water vapor adsorbent / desorbent such as an adsorption heat pump system, a desiccant air conditioning system, a humidity adjusting wall agent, and a humidity adjusting sheet.

It is a figure which shows the SEM photograph of the continuous-crystal silicoaluminophosphate obtained in Example 1 (a scale is 5 micrometers in the figure). 2 is a diagram showing an X-ray diffraction pattern of a continuous crystal silicoaluminophosphate obtained in Example 1. FIG. It is a figure which shows the water vapor | steam adsorption isotherm measured at 25 degreeC of the silicoaluminophosphate obtained in Experimental example 1. FIG. It is a figure which shows the water vapor | steam adsorption isotherm measured at 25 degreeC of the silicoaluminophosphate obtained in the comparative experiment example 1. FIG.

Hereinafter, the silicoaluminophosphate having the CHA structure and the AEI structure of the present invention will be described.
The present invention relates to silicoaluminophosphate. Silicoaluminophosphate is a zeolite-related substance containing silicon (Si), aluminum (Al), phosphorus (P) and oxygen (O) as main components. The composition of silicoaluminophosphate can be represented by the following formula (1).

_{_{_{_{(Si x Al y P z)}}}} O 2 (1)

(However, 0.05 <x ≦ 0.2, 0.45 ≦ y ≦ 0.55, 0.4 ≦ z ≦ 0.45, and x + y + z = 1)

The silicoaluminophosphate of the present invention has a CHA structure and an AEI structure.
The CHA structure is a structure that becomes a CHA type when expressed by the IUPAC structure code (hereinafter, simply referred to as “structure code”) defined by the Structure Commission of the International Zeolite Society (IZA). The AEI structure is a structure that becomes an AEI type when expressed by a structure code. Accordingly, the silicoaluminophosphate of the present invention has a silicoaluminophosphate having two crystal structures of a CHA structure and an AEI structure in its crystal structure, that is, a CHA structure and an interphase of an AEI structure (Intergrowth phase). Salt (hereinafter also referred to as “continuous-crystal silicoaluminophosphate”).
The intergrowth silicoaluminophosphate of the present invention has a CHA structure and an AEI structure, and the proportion of the CHA structure and the AEI structure in the crystal (hereinafter referred to as “intergrowth ratio”) is determined by the AEI structure. Over 50%. That is, the intergrowth silicoaluminophosphate of the present invention is a intergrowth silicoaluminophosphate having a larger AEI structure than a CHA structure in the crystal.

The intergrowth silicoaluminophosphate of the present invention has CHA / AEI <1 when the intergrowth ratio is expressed in CHA / AEI. When the proportion of AEI structure is 50% or less, that is, when CHA / AEI ≧ 1, when such a silicoaluminophosphate is used as a nitrogen oxide reduction catalyst in an atmosphere containing water, nitrogen The reduction in the oxide reduction rate becomes significant. From the viewpoint of further suppressing the reduction of the nitrogen oxide reduction rate in an atmosphere containing water, the structure of the intergrowth silicoaluminophosphate of the present invention has an AEI structure of 55% or more (CHA / AEI ≦ 0.82). It is preferable that it is 60% or more (CHA / AEI ≦ 0.67).
On the other hand, if the proportion of the AEI structure is 80% or less (CHA / AEI ≧ 0.25), and further 70% or less (CHA / AEI ≧ 0.43), the intergrowth silicoaluminophosphate of the present invention has a high temperature. Even if it is exposed to the bottom, its nitrogen oxide reduction characteristics are unlikely to deteriorate.

In the present invention, the intergrowth ratio can be obtained by the DIFFaX program. The DIFFaX program is a simulation program for simulating an XRD powder pattern for a continuous crystal such as zeolite, and is a program marketed by IZA.

The intergrowth silicoaluminophosphate of the present invention has the above intergrowth ratio. Therefore, the intergrowth silicoaluminophosphate of the present invention has an X-ray diffraction peak corresponding to an interplanar spacing (d value) of 5.22 ± 0.1 mm (CuKα ray as a radiation source) in the powder X-ray diffraction pattern. X-ray diffraction peak (CuKα ray as a radiation source) corresponding to an interplanar spacing of 5.16 ± 0.1 θ. X-ray diffraction peak having a peak top at 2θ = 17.20 ± 0.1 °).
Further, the intergrowth silicoaluminophosphate of the present invention has a peak corresponding to an interplanar spacing of 5.22 ± 0.1 mm in the powder X-ray diffraction pattern (2θ = 16.99 when CuKα rays are used as a radiation source). X-ray diffraction peak having a peak top at ± 0.1 °) and a peak corresponding to an interplanar spacing of 4.16 ± 0.05 mm (when 2θ = 21.34 ± 0.1 ° using CuKα ray as a radiation source) X-ray diffraction peak having a peak top). In the intergrowth silicoaluminophosphate of the present invention, the peak corresponding to the interplanar spacing of 4.16 ± 0.05% may be stronger than the peak corresponding to the interplanar spacing of 5.22 ± 0.1%. is there.

The composition of the intergrowth silicoaluminophosphate of the present invention is preferably a composition represented by the following formula.

_{_{_{(Si x Al y P z)}}} O 2

(However, x + y + z = 1, 0.05 <x ≦ 0.15)

When x exceeds 0.05, preferably 0.07 or more, the nitrogen oxide reduction rate becomes higher. On the other hand, when x is 0.15 or less, further 0.13 or less, and further less than 0.12, the intergrowth silicoaluminophosphate of the present invention has a high nitrogen oxide reduction rate and water. Even when exposed to an atmosphere containing nitrogen, the nitrogen oxide reduction rate is likely to be a nitrogen oxide reduction catalyst that is unlikely to decrease.

The intergrowth silicoaluminophosphate of the present invention only needs to have a particle size that can be used as a nitrogen oxide reduction catalyst. Examples of such a particle size include an average particle size of 10 μm or less, further 7 μm or less, and further 5 μm or less. Further, when the average particle size is 0.5 μm or more, the operability (handling) when applied to a catalyst carrier such as a honeycomb is increased. From the viewpoint of balancing nitrogen oxide reduction characteristics and operability, the average particle diameter may be 0.5 μm or more, and more preferably 1 μm or more.
In the present invention, the average particle diameter is an average of the particle diameters of primary particles. Therefore, it is different from an average particle diameter of secondary particles formed by aggregation of primary particles, that is, so-called aggregate particles. The average particle size is, for example, randomly selected from a plurality of (for example, 100 or more) particles of intergrowth silicoaluminophosphate observed by observation with a scanning electron microscope (hereinafter referred to as “SEM”). It can be measured by determining the average particle diameter obtained by measuring the particle diameter.

The surface area of the intergrowth silicoaluminophosphate of the present invention may be such that a nitrogen oxide reduction reaction is efficiently generated. Examples of the BET specific surface area of the intergrowth silicoaluminophosphate of the present invention include 500 m ² / g or more and 800 m ² / g or less.
The intergrowth silicoaluminophosphate of the present invention has a so-called porous structure having many pores. Therefore, in the intergrowth silicoaluminophosphate of the present invention, there is substantially no correlation between the size of the surface area and the size of the average particle diameter.

The intergrowth silicoaluminophosphate of the present invention contains a metal. The metal contained in the intergrowth silicoaluminophosphate of the present invention is at least one selected from the group consisting of Group VIIIB elements, Group IB elements and Group VIIB elements of the periodic table, and includes platinum (Pt) and palladium (Pd). , Rhodium (Rh), iron (Fe), copper (Cu), cobalt (Co), manganese (Mn), and indium (In), and preferably copper. preferable. The inclusion of these metals in the intergrowth silicoaluminophosphate of the present invention tends to be a catalyst having a particularly high nitrogen oxide reduction rate when used as a nitrogen oxide reduction catalyst. In particular, since the intergrowth silicoaluminophosphate of the present invention contains copper, it is likely to be a nitrogen oxide reduction catalyst that exhibits a high nitrogen oxide reduction rate not only at a high temperature of 500 ° C. or higher but also at a low temperature below that. .

Although the metal content is arbitrary, for example, the weight of the metal contained is 0.3 wt% or more, further 0.6 wt% or more, based on the weight of the continuous silicoaluminophosphate of the present invention. Furthermore, it can mention that it is 0.8 weight% or more. On the other hand, if the metal content is 5% by weight or less, further 4% by weight or less, and further 3% by weight or less, the effect of improving the nitrogen oxide reduction characteristics due to the metal content is easily obtained.

Next, the manufacturing method of the intergranular silicoaluminophosphate of this invention is demonstrated.
The method for producing a continuous silicoaluminophosphate according to the present invention includes a metal-containing step of containing a metal in a silicoaluminophosphate having a CHA structure and an AEI structure, wherein the proportion of the AEI structure exceeds 50%. It is a manufacturing method characterized by having.
As a particularly preferred method for producing the intergrowth silicoaluminophosphate of the present invention, a crystallization step of crystallizing a mixture containing a tertiary amine, and the proportion of the AEI structure obtained by the crystallization step exceeds 50%. The metal-containing process which makes a silicoaluminophosphate which has the CHA structure and AEI structure characterized by including a metal can be mentioned.

The production method of the present invention is characterized in that the proportion of AEI structure exceeds 50% (CHA / AEI <1), and silicoaluminophosphate having a CHA structure and an AEI structure (intergranular silicoaluminophosphate). A metal-containing step of containing a metal. By containing the metal, the resulting intergranular silicoaluminophosphate becomes a nitrogen oxide reduction catalyst with little reduction in nitrogen oxide reduction rate even when exposed to an atmosphere containing moisture.

The metal contained in the intergrowth silicoaluminophosphate is at least one selected from the group consisting of group VIIIB elements, group IB elements and group VIIB elements of the periodic table, and includes platinum (Pt), palladium (Pd), rhodium ( Rh), iron (Fe), copper (Cu), cobalt (Co), manganese (Mn) and at least one selected from the group of indium (In) are preferable, and copper is more preferable. By containing these metals, the intergrowth silicoaluminophosphate obtained becomes a nitrogen oxide reduction catalyst having a high nitrogen oxide reduction rate. Furthermore, the intergrowth silicoaluminophosphate contained copper, that is, the intergrowth silicoaluminophosphate was a copper-containing intergrowth silicoaluminophosphate, which was used as a nitrogen oxide reduction catalyst. In this case, the catalyst tends to be a nitrogen oxide reduction catalyst exhibiting a high nitrogen oxide reduction rate not only at a high temperature of 500 ° C. or higher, but also at a low temperature lower than that.

The intergrowth silicoaluminophosphate used in the metal-containing process is at least one of proton type (H ⁺ type) silicoaluminophosphate or ammonia type (NH ₄ ⁺ type) intergrowth silicoaluminophosphate. It is preferable that Thereby, it exists in the tendency which can contain the metal to a continuous crystal silicoaluminophosphate more efficiently.

In order to convert the continuous crystal silicoaluminophosphate into a proton-type (H ⁺ -type) continuous crystal silicoaluminophosphate, for example, before the metal-containing step, the continuous crystal silicoaluminophosphate is converted to 400 in the atmosphere. Firing at a temperature of 0 ° C. or higher is mentioned. In addition, in order to convert the continuous crystal silicoaluminophosphate into an ammonia type (NH ₄ ⁺ type) continuous crystal silicoaluminophosphate, for example, the intergranular silicoaluminophosphate is converted into an ammonium chloride aqueous solution before the metal-containing step. Ion exchange.

The raw material used in the metal-containing step is any one selected from the group consisting of nitrates, sulfates, acetates, chlorides, complex salts, oxides and complex oxides containing metals to be included in the intergrowth silicoaluminophosphate, and Mixtures of these can be used.

In the metal-containing step, if a metal is contained in the intergrowth silicoaluminophosphate, an arbitrary method can be selected as the containing method. Examples of the content method include an ion exchange method, an impregnation support method, an evaporation to dryness method, a coprecipitation method, a precipitation method, or a physical mixing method.
The metal content is arbitrary. For example, the weight of the metal contained is 0.3% by weight or more, further 0.6% by weight or more, or further, based on the weight of the intergrowth silicoaluminophosphate. Can include a metal in intergrowth silicoaluminophosphate so that it may become 0.8 weight% or more. On the other hand, if the metal is contained in the intergrowth silicoaluminophosphate so that the metal content is 5% by weight or less, further 4% by weight or less, and further 3% by weight or less, nitrogen oxidation due to metal content There is a tendency that improvement of the product reduction characteristic is easily obtained.

In the manufacturing method of this invention, it is preferable to have a calcination process which calcinates the continuous-crystal silicoaluminate obtained by the metal containing process. Thereby, it becomes easy to bond a continuous crystal silicoaluminophosphate and a metal more firmly.
As long as salts such as nitric acid, sulfuric acid, and acetic acid incorporated into the intergrowth silicoaluminophosphate in the metal-containing step can be removed, any method can be applied as the calcination method. As the calcination method, for example, intergranular silicoalumino acid obtained in the metal-containing step at a temperature of 400 ° C. or higher and 1000 ° C. or lower in an atmosphere or an oxidizing atmosphere such as oxygen gas or an inert atmosphere such as nitrogen or helium. Treating the salt.

In the production method of the present invention, the intergrowth silicoaluminophosphate used in the metal-containing step has an AEI structure ratio of more than 50%, that is, the intergrowth silicoaluminoline having a larger AEI structure than the CHA structure in the structure. Acid salt. Therefore, in the powder X-ray diffraction pattern, an X-ray diffraction peak corresponding to an interplanar spacing of 5.24 ± 0.1 mm (peak top at 2θ = 16.93 ± 0.1 ° when CuKα ray is used as a radiation source) X-ray diffraction peak corresponding to an interplanar spacing of 5.16 ± 0.1 mm (peaked at 2θ = 17.18 ± 0.1 ° when CuKα ray is used as a radiation source). X-ray diffraction peak with a top) is shown.

Further, the intergrowth silicoaluminophosphate used in the metal-containing step has a peak corresponding to a surface spacing of 5.24 ± 0.1 mm in the powder X-ray diffraction pattern (2θ = 16 when CuKα ray is used as a radiation source). X-ray diffraction peak having a peak top at .93 ± 0.1 °) and a peak corresponding to an interplanar spacing of 4.17 ± 0.05 mm (2θ = 21.31 ± 0.1 using CuKα rays as a radiation source). X-ray diffraction peak having a peak top at 0 °. In such a continuous crystal silicoaluminophosphate, the peak corresponding to the interplanar spacing of 4.16 ± 0.05% may be higher in intensity than the peak corresponding to the interplanar spacing of 5.22 ± 0.1%. is there.
More preferably, the intergrowth silicoaluminophosphate used in the metal-containing step has a powder X-ray diffraction pattern shown in Table 1 below.

In the production method of the present invention, it is preferable that the continuous silicoaluminophosphate used in the metal-containing step has a high amount of solid acid. When the amount of the solid acid is high, the obtained metal-containing intergrowth silicoaluminophosphate is likely to be a nitrogen oxide reduction catalyst exhibiting a high nitrogen oxide reduction rate. Therefore, the solid acid amount of the intergrowth silicoaluminophosphate used for the metal-containing step is preferably 0.5 mmol / g or more, more preferably 0.6 mmol / g or more, and 0.7 mmol / g or more. More preferably. When the amount of the solid acid is 0.5 mmol / g or more, the obtained metal-containing continuous crystal silicoaluminophosphate is likely to be a nitrogen oxide reduction catalyst exhibiting a higher nitrogen oxide reduction rate. As the amount of solid acid increases, the nitrogen oxide reduction rate tends to increase. On the other hand, if the amount of solid acid is too large, the crystal structure may become unstable. Therefore, when the solid acid amount is 1.4 mmol / g or less, further 1.2 mmol / g or less, or even 1.0 mmol / g or less, the obtained metal-containing intergrowth silicoaluminophosphate is nitrogen. The oxide reduction rate is high, and the crystal structure tends to be stable.

Here, the “solid acid” is an index for evaluating the catalytic activity of silicoaluminophosphate.
The solid acid can be confirmed and quantified by a general NH ₃ -TPD method. The solid acid has a property of adsorbing ammonia (NH ₃ ). The NH ₃ -TPD method is a measurement method using this property, in which ammonia is adsorbed and desorbed from silicoaluminophosphate, and the ammonia desorbed from silicoaluminate in a specific temperature range is confirmed and quantified, This is a measurement method for confirming and quantifying this as a solid acid.
As the NH ₃ -TPD method, a method having the following three steps can be exemplified.

1) a pretreatment process for removing gas or moisture adsorbed on silicoaluminophosphate,
2) Ammonia adsorption process for adsorbing ammonia on silicoaluminophosphate, and 3) Ammonia desorption process for desorbing ammonia adsorbed on silicoaluminophosphate therefrom

As the pretreatment step, an inert gas can be circulated through the silicoaluminophosphate at a treatment temperature of 400 to 600 ° C. Further, as the ammonia adsorption step, an inert gas containing 1 to 20% by volume of ammonia can be circulated through the silicoaluminophosphate at a treatment temperature of 100 to 150 ° C. Further, as the ammonia desorption step, the temperature can be raised to about 100 ° C. to 700 ° C. while circulating an inert gas through the silicoaluminophosphate.

In the ammonia desorption process, the solid acid can be confirmed and quantified by confirming and quantifying the desorbed ammonia. The ammonia adsorbed on the silicoaluminophosphate includes ammonia that is physically adsorbed and ammonia that is adsorbed by a solid acid. When the solid acid is confirmed and quantified, it is necessary to separate both of them. For example, the presence of a solid acid can be confirmed with an ammonia peak desorbed at a temperature of 250 to 450 ° C., and the amount of ammonia corresponding to the peak is quantified, and this is regarded as the solid acid amount.

The intergrowth silicoaluminophosphate used in the metal-containing step only needs to have a particle size that can be used as a nitrogen oxide reduction catalyst. Examples of such a particle size include an average particle size of 10 μm or less, further 7 μm or less, and further 5 μm or less. Further, when the average particle size is 0.5 μm or more, the operability (handling) when applied to a catalyst carrier such as a honeycomb is increased. From the viewpoint of balancing nitrogen oxide reduction characteristics and operability, the average particle diameter may be 0.5 μm or more, and more preferably 1 μm or more.
A continuous crystal silicoaluminophosphate preferable for use in the metal-containing step can be obtained, for example, by a production method having a crystallization step of crystallizing a mixture containing a tertiary amine.

In a conventionally reported method for producing intergrowth silicoaluminophosphate, a quaternary amine such as tetraethylammonium hydroxide (hereinafter referred to as “SDA”) is used as an organic mineralizing agent (Structure directing agents; hereinafter referred to as “SDA”). It was essential to crystallize using a compound containing “TEAOH”. On the other hand, in the crystallization step of obtaining a silicoalumino salt that is preferable for use in the metal-containing step, the intergrowth silicoaluminophosphate can be crystallized without using a compound containing a quaternary amine as an essential component. it can.

In the crystallization step, a mixture containing a tertiary amine is crystallized. Thereby, it becomes easy to obtain a continuous crystal silicoaluminophosphate preferable for use in the metal-containing step of the present invention.
In the crystallization step, the tertiary amine is preferably at least one selected from the group consisting of triethylamine, methyldiethylamine, diethylpropylamine, ethyldipropylamine, and diethylisopropylamine, and more preferably triethylamine. .

In the crystallization step, it is preferable to crystallize a mixture containing triethylamine as SDA and containing a silicon (Si) source, a phosphorus (P) source, an aluminum (Al) source and water (H ₂ O).

The raw materials for the silicon source, phosphorus source and aluminum source can be selected arbitrarily. The following can be illustrated as these raw materials.
As the silicon source, at least one water-soluble silicon compound consisting of colloidal silica, silica sol and water glass, or at least one kind consisting of silicon compound dispersed in a solvent, amorphous silica, fumed silica and sodium silicate. And solid silicon compounds, organosilicon compounds such as ethyl orthosilicate, and mixtures thereof.

Examples of the phosphorus source include one or more water-soluble phosphorus compounds of orthophosphoric acid and phosphorous acid, one or more solid phosphorus compounds of condensed phosphoric acid such as pyrophosphoric acid and calcium phosphate, and mixtures thereof. be able to.
As an aluminum source, at least one water-soluble aluminum compound selected from the group consisting of aluminum sulfate solution, sodium aluminate solution and alumina sol, or an aluminum compound dispersed in a solvent, amorphous alumina, pseudoboehmite, boehmite, aluminum hydroxide, sulfuric acid Mention may be made of at least one solid aluminum compound selected from the group of aluminum and sodium aluminate, organoaluminum compounds such as aluminum isopropoxide, and mixtures thereof.

Furthermore, a compound containing two or more selected from the group of silicon, phosphorus and aluminum can also be used as a raw material. Examples of such compounds include aluminophosphate gel and silicoaluminophosphate gel.
A mixture is obtained by mixing these raw materials with water and SDA. Arbitrary methods can be used for mixing raw materials and the like when obtaining the mixture. For example, each raw material, water, and SDA may be mixed one by one in order, or two or more raw materials may be mixed simultaneously.

You may adjust pH of the obtained mixture as needed. When adjusting the pH of the mixture, for example, an acid such as hydrochloric acid, sulfuric acid or hydrofluoric acid, or an alkali such as sodium hydroxide, potassium hydroxide or ammonium hydroxide may be mixed into the mixture.
In the crystallization process, the composition of silicon, phosphorus, aluminum, water and SDA of the mixture is as follows when the silicon, phosphorus and aluminum in the mixture are regarded as SiO ₂ , P ₂ O ₅ and Al ₂ O ₃ respectively. A composition is preferred.

P ₂ O ₅ / Al ₂ O ₃ 0.7 or more, 1.5 or less SiO ₂ / Al ₂ O ₃ 0.1 or more, 1.2 or less H ₂ O / Al ₂ O ₃ 5 or more, 100 or less SDA / Al ₂ O ₃ 0.5 or more and 5 or less

In addition, each ratio in the said composition is molar ratio.

As for the ratio of phosphorus and aluminum in the mixture, P ₂ O ₅ / Al ₂ O ₃ is preferably 0.7 or more and more preferably 0.8 or more in terms of molar ratio. When P ₂ O ₅ / Al ₂ O ₃ is 0.7 or more, the yield of the obtained continuous crystal silicoaluminophosphate tends to increase. On the other hand, if P ₂ O ₅ / Al ₂ O ₃ is 1.5 or less, and further 1.2 or less, it is easy to obtain a continuous crystal silicoaluminophosphate in a shorter crystallization time.
The ratio of silicon and aluminum in the mixture is preferably such that SiO ₂ / Al ₂ O ₃ is 0.1 or more and more preferably 0.2 or more in terms of molar ratio. When SiO ₂ / Al ₂ O ₃ is 0.1 or more, a continuous crystal silicoaluminophosphate having a larger amount of solid acid is easily obtained. On the other hand, if SiO ₂ / Al ₂ O ₃ is 1.2 or less, and further 0.8 or less, a continuous crystal silicoaluminophosphate is easily obtained in a shorter crystallization time.

As for the ratio of water and aluminum in the mixture, H ₂ O / Al ₂ O ₃ is preferably 5 or more and more preferably 15 or more in terms of molar ratio. When the H ₂ O / Al ₂ O ₃ is 5 or more, the resulting mixture becomes rich in fluidity. Thereby, the mixture tends to be more excellent in operability. It is preferred _H 2 O / _Al 2 _{O 3} in the mixture is _small, H 2 O / _Al 2 _{O 3} is 100 or less, if more than 70 or less, a mixture having a fluidity suitable for crystallization Become. Furthermore, since H ₂ O / Al ₂ O ₃ is 60 or less, crystallization can be performed at a higher concentration, which tends to be advantageous in industrial production.

The ratio of SDA and aluminum in the mixture is preferably such that SDA / Al ₂ O ₃ is 0.5 or more, and more preferably 1 or more in terms of molar ratio. This makes it easier to obtain a continuous silicoaluminophosphate having a higher amount of solid acid. The larger SDA / Al ₂ O ₃ is, the easier it is to obtain intergrowth silicoaluminophosphate. If SDA / Al ₂ O ₃ is 5 or less, further 4 or less, and further 3 or less, a continuous crystal silicoaluminophosphate having a large amount of solid acid is more easily obtained.
In the crystallization step, the mixture preferably contains seed crystals. When the mixture contains seed crystals, intergranular silicoaluminophosphate can be easily obtained in a short crystallization time.

The mixture preferably contains 0.05% by weight or more of seed crystals, more preferably 0.1% by weight or more, and still more preferably 0.5% by weight or more. When the mixture contains 0.05% by weight or more of seed crystals, the crystallization time is easily shortened. In addition, when the mixture contains seed crystals, the crystal grain size of the obtained continuous crystal silicoaluminophosphate tends to be uniform. If the crystal grain size of the obtained continuous crystal silicoaluminophosphate becomes uniform, the seed crystal content in the mixture is arbitrary. Therefore, the upper limit of the seed crystal content can be, for example, 10% by weight or less, further 5% by weight or less, and further 2% by weight or less.

The content (% by weight) of the seed crystals contained in the mixture is when silicon, phosphorus and aluminum in the mixture excluding the seed crystals are regarded as SiO ₂ , P ₂ O ₅ and Al ₂ O ₃ , respectively. The ratio of the weight of the seed crystal to the total weight of
Furthermore, the type of seed crystal is preferably silicoaluminophosphate, more preferably intergrowth silicoaluminophosphate, and intergrowth silicoaluminophosphate having an AEI structure exceeding 50%. Further preferred.

As a preferable mixture for obtaining a continuous crystal silicoaluminophosphate preferable for use in the metal-containing step, a mixture having the following composition can be exemplified.

P ₂ O ₅ / Al ₂ O ₃ 0.8 or more, 1.2 or less SiO ₂ / Al ₂ O ₃ 0.2 or more, 0.8 or less H ₂ O / Al ₂ O ₃ 15 or more, 60 or less SDA / Al ₂ O ₃ 1 or more, 3 or less Seed crystal 0 wt% or more, 5 wt% or less

In addition, each ratio in the said composition is a molar ratio, SDA is a triethylamine, and a seed crystal is a continuous crystal silicoaluminophosphate.

In the crystallization step, if the mixture crystallizes, the crystallization method can be appropriately selected. A preferred crystallization method is hydrothermal treatment of the mixture. Hydrothermal treatment may be performed by placing the mixture in a sealed pressure resistant container and heating the mixture.
The crystallization temperature is preferably 130 ° C. or higher, and more preferably 150 ° C. or higher. If the crystallization temperature is 130 ° C. or higher, the intergrowth silicoaluminophosphate crystallizes in a relatively short crystallization time, for example, 100 hours or less, and further 80 hours or less. The higher the crystallization temperature, the shorter the crystallization time. However, for example, if the crystallization temperature is 220 ° C. or lower, further 200 ° C. or lower, even if the crystallization time is 5 hours or longer, 10 hours or longer, or even 15 hours or longer, the intergrowth silicon aluminum Norolinate is easily crystallized.
In the crystallization step, it is preferable to crystallize the mixture while stirring. Thereby, the particle diameter of the obtained intergrowth silicoaluminophosphate tends to be more uniform.

In the manufacturing method of the continuous crystal silicoaluminophosphate preferable to use for a metal containing process, you may have a washing | cleaning process and a drying process further.
In the washing step, the crystallized continuous silicoaluminophosphate is separated from the liquid phase by any solid-liquid separation method such as filtration, decantation or centrifugation. The intergrowth silicoaluminophosphate after solid-liquid separation may be washed with water as appropriate.
In the drying step, the filtered silicoaluminophosphate after drying is dried. Examples of the drying method include a method of drying at 90 ° C. or higher and 120 ° C. or lower for 5 hours or longer in the air.

In a method for producing a continuous crystal silicoaluminophosphate preferable for use in the metal-containing step, the method may have a firing step and a re-washing step.
In the firing process, the dried silicoaluminophosphate is fired. As a result, SDA taken into the silicoaluminophosphate during crystallization can be removed. By removing SDA from the intergrowth silicoaluminophosphate, when the intergrowth silicoaluminophosphate obtained as a nitrogen oxide reduction catalyst is used, this tends to exhibit higher nitrogen oxide reduction characteristics.
In the firing step, any firing method can be applied as long as SDA can be removed from the intergrowth silicoaluminophosphate. Examples of such a firing method include firing at a firing temperature of 400 ° C. or more and 800 ° C. or less in the atmosphere or in an oxidizing atmosphere such as oxygen gas.

In the re-cleaning step, the intergrowth silicoaluminophosphate is re-cleaned. When intergrowth silicoaluminophosphate is crystallized using a material containing alkali metal or the like as a raw material, the metal derived from the raw material such as alkali metal remains on the surface or pores of intergrowth silicoaluminophosphate. Sometimes.
In the re-cleaning step, any cleaning method can be applied as long as the metal derived from the raw material remaining in the intergrowth silicoaluminophosphate can be removed therefrom. Examples of such re-cleaning methods include acid cleaning and ion exchange.
Said baking process and re-washing process can be performed as needed. Therefore, you may perform any one of only a baking process or only a re-washing process. Moreover, when performing both a baking process and a re-washing process, you may perform any of these order first.

In the production method of the present invention, the thus obtained intergrowth silicoaluminophosphate is subjected to a metal-containing step, that is, a crystallization step of crystallizing a mixture containing a tertiary amine, and the crystallization step. It is more preferable to use a metal-containing step of containing a metal in the obtained continuous crystal silicoaluminophosphate.

In addition, the continuous crystal silicoaluminophosphate used for a metal containing process can be used as a water vapor | steam adsorption / desorption agent.
That is, in a system such as an adsorption heat pump system and a desiccant air conditioning system, a water vapor adsorption / desorption agent for discharging water vapor to the outside of the system system is used. In this system, water vapor (water) is adsorbed on the water vapor adsorbing / desorbing agent at an adsorption temperature of 25 ° C. to 40 ° C., and then heated to a desorption temperature of 60 ° C. to 100 ° C. The water adsorbed on the water vapor adsorbing / desorbing agent is desorbed by heating, whereby the water vapor adsorbing / desorbing agent is dried. The dried water vapor adsorbing / desorbing agent is cooled to the adsorption temperature and used again for water adsorption. In this system, such adsorption and desorption of water vapor (hereinafter referred to as “adsorption / desorption”) is repeated. As a water vapor adsorption / desorption agent used in such a system, an adsorbent having a large amount of water vapor adsorption / desorption in the temperature range from the adsorption temperature to the desorption temperature is desired, and various adsorbents have been proposed.

Japanese Unexamined Patent Publication No. 2003-340236 reports a water vapor adsorption / desorption agent for adsorption heat pumps containing a zeolite-related substance. The zeolite-related material was a zeolite-related material containing aluminum, phosphorus and silicon in the skeleton structure and having a structure code of CHA. The water vapor adsorption / desorption agent containing the zeolite-related substance has a water adsorption amount change of 0.15 when the relative vapor pressure is changed by 0.15 in the range of the relative vapor pressure of 0.05 to 0.30 on the water vapor adsorption isotherm. It had a relative vapor pressure range of 18 g / g or more.

Japanese Patent Application Laid-Open No. 2007-181795 discloses an adsorption / desorption agent composed of a zeolite-related substance containing at least Al and P as elements constituting the skeleton and Mg or Si. The zeolite-related substance has a one-dimensional structure in which pores have a diameter of 3.8 to 7.1 angstroms, and the crystal structure is an ATS structure, ATN structure, AWW structure, LTL structure, or SAS structure. It had any crystal structure.

The water vapor adsorption / desorption agents proposed so far have not been sufficient in the amount of water vapor adsorption / desorption.
A water vapor adsorbing and desorbing agent (hereinafter referred to as “the present adsorbing and desorbing agent”) containing intergrowth silicoaluminophosphate solves the above problems, and uses an adsorption heat pump system, a desiccant air conditioning system, a humidity adjusting wall agent, and humidity. It is possible to provide a water vapor adsorbing / desorbing agent useful for an adjustment sheet. That is, when this adsorption / desorption agent is used as a moisture removal system, a vapor adsorption / desorption agent having a high vapor adsorption / desorption amount can be provided.

The present inventor examined the crystal structure and water vapor adsorption / desorption characteristics of silicoaluminophosphate. As a result, in the silicoaluminophosphate having a crystal structure composed of a CHA structure and an AEI structure, the intergranular ratio of the CHA structure and the AEI structure contained in the silicoaluminophosphate is controlled. It has been found that it has excellent water vapor adsorption and desorption characteristics.
That is, this adsorption / desorption agent is represented by the following general formula (2), and is a crystal comprising a CHA structure and an AEI structure characterized by a powder X-ray diffraction (hereinafter referred to as “XRD”) pattern shown in Table 2 below. A water vapor adsorption / desorption agent comprising silicoaluminophosphate having a structure.

_{_{_{_{(Si x Al y P z)}}}} O 2 (2)

(In the formula, x represents the mole fraction of Si, y represents the mole fraction of Al, z represents the mole fraction of P, and x + y + z = 1).

Hereinafter, this adsorption / desorption agent will be described.
This adsorbent / desorbent is a water vapor adsorbent / desorbent containing a silicoaluminophosphate having a crystal structure composed of a CHA structure and an AEI structure (hereinafter referred to as “continuous crystal SAPO”). It may be an adsorption / desorption agent.
The intergrowth SAPO has a crystal structure composed of a CHA structure and an AEI structure (hereinafter referred to as “continuous crystal structure”). Therefore, silicoaluminophosphate whose crystal structure consists only of the CHA structure, or silicoaluminophosphate whose crystal structure consists only of the AEI structure is different from the intergrowth SAPO. Furthermore, intergrowth SAPO is also different from silicoaluminophosphate obtained by mixing a silicoaluminophosphate having a CHA structure and a silicoaluminophosphate having an AEI structure.

Intergrowth SAPO contained in this adsorption / desorption agent has the XRD pattern shown in Table 2.
This XRD pattern shows a broad peak that does not exist in the XRD pattern of SAPO-34 silicoaluminophosphate, with a surface spacing of 6.60 mm (diffraction angle 2θ = 13.4 °), 5.24 mm (diffraction angle 2θ). = 16.9 °) and 4.17 ° (diffraction angle 2θ = 21.3 °). These broad peaks indicate that the intergrowth SAPO contained in the present adsorption / desorption agent has a intergranular crystal structure.

Furthermore, the interstitial SAPO contained in the present adsorption / desorption agent preferably has a crystal structure retention of 50% or more and 100% or less. The crystal structure retention is the ratio of the crystallinity after storage to the crystallinity before storage in 80 ° C. saturated water vapor for 8 days.
In the present adsorbent / desorbent, the crystallinity can be determined from the total peak intensity of main peaks in the XRD pattern of silicoaluminophosphate. For intergrowth SAPO, the main peaks in the XRD pattern are 2θ = 16.1 ± 0.2 °, 19.1 ± 0.2 °, 20.7 ± 0.2 °, and 26.1 ± 0. 4 of 2 °. For SAPO-34, the main peaks in the XRD pattern are 2θ = 16.1 ± 0.2 °, 17.8 ± 0.2 °, 20.8 ± 0.2 °, and 25.1. Four of ± 0.2 °. In addition, the value (°) of 2θ in the present adsorption / desorption agent is a value when copper Kα rays are used as a radiation source.

The ratio of CHA structure and AEI structure of intergrowth SAPO contained in the adsorption / desorption agent (intergrowth ratio; hereinafter referred to as “intergrowth ratio”) is 80/20 to 20/80 in CHA / AEI ratio. It is preferably 50/50 to 30/70, more preferably 45/55 to 30/70. If the intergrowth ratio is within this range as the CHA / AEI ratio, the water resistance of the intergrowth SAPO is unlikely to decrease, and the crystal structure retention rate is unlikely to decrease.
Further, the interstitial SAPO contained in the present adsorption / desorption agent has a Si mole fraction x of 0.05 <x ≦ 0.10 and an Al mole fraction y of 0.47 ≦ in the general formula (2). It is preferable that y ≦ 0.52 and the molar fraction z of P is 0.40 ≦ z ≦ 0.46. If the composition is in the above range, the crystal structure retention tends to be higher.

Furthermore, the adsorption / desorption agent of the present invention preferably has a solid acid amount after hydration treatment (hereinafter referred to as “solid acid retention rate”) of 50% or more with respect to the solid acid amount before hydration treatment. If the solid acid retention rate is 50% or more, the water resistance of the adsorption / desorption agent is likely to be higher. The solid acid becomes an active site for water vapor adsorption. Therefore, the higher the solid acid retention rate before and after the hydration treatment, the higher the water resistance and the more preferable properties as a water vapor adsorption / desorption agent.

The solid acid can be confirmed and quantified by a general NH ₃ -TPD method. The solid acid has a property of adsorbing ammonia (NH ₃ ). The NH ₃ -TPD method is a measurement method using this property, in which ammonia is adsorbed and desorbed from silicoaluminophosphate, and the ammonia desorbed from silicoaluminate in a specific temperature range is confirmed and quantified, This is a measurement method for confirming and quantifying this as a solid acid.

As the NH ₃ -TPD method, a method having the following three steps can be exemplified.
1) Pretreatment process to remove gas and moisture adsorbed on silicoaluminophosphate 2) Ammonia adsorption process to adsorb ammonia on silicoaluminophosphate, and 3) Ammonia adsorbed on silicoaluminophosphate , Ammonia desorption process to desorb from there

As the pretreatment step, an inert gas can be circulated through the silicoaluminophosphate at a treatment temperature of 400 to 600 ° C. Further, as the ammonia adsorption step, it is possible to exemplify that an inert gas containing 1 to 20% by volume of ammonia is circulated through the silicoaluminophosphate at a treatment temperature of 100 to 150 ° C. Further, as the ammonia desorption step, the temperature can be raised to about 100 ° C. to 700 ° C. while circulating an inert gas through the silicoaluminophosphate.

Furthermore, the present adsorption / desorption agent may contain intergrowth SAPO on which an alkaline earth metal is supported. By supporting an alkaline earth metal on the intergrowth SAPO, a decrease in the amount of solid acid after the treatment (hereinafter referred to as “cycle hydration treatment”) that has been subjected to multiple hydration treatments is easily suppressed. .
Here, as the cycle hydration treatment, for example, after the treatment for allowing the water vapor adsorbent / desorbent to stand in a saturated water vapor atmosphere of 60 ° C. or higher and 100 ° C. or lower for 1 hour or longer and 60 days or shorter, A treatment for allowing the water vapor adsorbent / desorbent to stand for 1 hour or more and 60 days or less in a dry atmosphere (ie, an atmosphere having a water content of 0.05% by volume or less) at 1 ° C. or less is defined as 1 cycle. Repeating 10 times or more and 50 times or less.

The alkaline earth metal is preferably at least one selected from the group consisting of magnesium (Mg), calcium (Ca), strontium (Sr), and barium (Ba), and more preferably calcium.
When the alkaline earth metal is calcium, the calcium loading is preferably 0.1% by weight or more, more preferably 0.2% by weight or more, and even more preferably 0.4% by weight or more. If the amount of calcium supported is within this range, the decrease in the amount of solid acid after the cycle hydration treatment is more easily suppressed. Further, if the calcium content is 2.5% by weight or less, further 2% by weight or less, and further 1.5% by weight or less, an effect of suppressing a sufficient decrease in the amount of solid acid can be obtained. In addition, when alkaline-earth metal is other than calcium, the content should just be a quantity comparable as the amount of substances (mol) corresponding to said calcium content (weight%).

This adsorption / desorption agent can be in any form. For example, it may be used as a powder, or may be used as a coating or a molded body. When used as a coating, the present adsorbent / desorbent may be used as a powder slurry and coated on a substrate such as a honeycomb rotor.
When used as a molded body, a binder or molding aid may be mixed with the present adsorption / desorption agent and used as a granular molded body. Furthermore, it may be integrally formed with other materials, or may be formed into a sheet by mixing with paper or resin.

The manufacturing method of this adsorption / desorption agent is demonstrated below.
This adsorbent / desorbent can be obtained by any production method as long as it contains intergrowth SAPO. Furthermore, the intergrowth SAPO is preferably obtained by a production method in which a reaction mixture having the following molar composition ratio is held at a temperature of 130 ° C. or higher and 220 ° C. or lower for 5 hours or longer and 100 hours or shorter.

P ₂ O ₅ / Al ₂ O ₃ (molar ratio) = 0.7 to 1.5
SiO ₂ / Al ₂ O ₃ (molar ratio) = 0.1 to 1.2
H ₂ O / Al ₂ O ₃ (molar ratio) = 5 to 100
R / Al ₂ O ₃ (molar ratio) = 0.5-5
(R represents an organic mineralizer.)

The silicon source is not particularly limited, and examples thereof include a water-soluble or water-dispersed silicon source, a solid silicon source, or an organic silicon source. The water-soluble silicon source is at least one selected from the group of colloidal silica, silica sol, and water glass, and the solid silicon source is at least one selected from the group of amorphous silica, fumed silica, and sodium silicate. Examples of the seed and organosilicon source include ethyl orthosilicate.

Examples of the phosphorus source include a water-soluble phosphorus source such as orthophosphoric acid or phosphorous acid, a condensed phosphoric acid such as pyrophosphoric acid, and a solid phosphorus source such as calcium phosphate.
Examples of the aluminum source include a water-soluble or water-dispersed aluminum source, a solid aluminum source, and an organic aluminum source. As a water-soluble aluminum source, at least one selected from the group consisting of an aluminum sulfate solution, a sodium aluminate solution, and an alumina sol, and as a solid aluminum source, amorphous alumina, pseudoboehmite, boehmite, aluminum hydroxide, aluminum sulfate, and alumine Aluminum isopropoxide can be exemplified as at least one selected from the group of sodium acid and an organoaluminum source.

As the organic mineralizer, for example, tertiary amine, further triethylamine, methyldiethylamine, diethylpropylamine, ethyldipropylamine, and diethylisopropylamine, at least one tertiary amine, or even triethylamine is used. Can be mentioned. When triethylamine is used as the organic mineralizer, a tertiary amine other than triethylamine or another organic mineralizer used for the synthesis of silicoaluminophosphate and triethylamine may be used in combination. Examples of the other organic mineralizer include one or more selected from the group consisting of tetraethylammonium salt, diethylamine, methylbutylamine, morpholine, cyclohexylamine, and propylamine.

The order of adding these silicon source, phosphorus source, aluminum source, water, and organic mineralizer is not particularly limited. The reaction mixture may be prepared by adding each of them individually or by simultaneously mixing two or more raw materials. Furthermore, an amorphous aluminophosphate gel and an amorphous silicoaluminophosphate gel are prepared in advance, and a reaction mixture is prepared by adding and mixing water and an organic mineralizer and, if necessary, a silicon source, a phosphorus source and an aluminum source. It may be prepared. If necessary, the reaction mixture may be adjusted to pH with an acid such as hydrochloric acid, sulfuric acid, hydrofluoric acid, sodium hydroxide, potassium hydroxide, ammonium hydroxide, or an alkali.

The phosphorus source and the aluminum source are mixed so that the P ₂ O ₅ / Al ₂ O ₃ molar ratio is 0.7 to 1.5 in terms of oxide. If the P ₂ O ₅ / Al ₂ O ₃ molar ratio is 0.7 or more, a decrease in yield can be prevented. When the P ₂ O ₅ / Al ₂ O ₃ molar ratio is 1.5 or less, the crystallization speed is hardly lowered, and crystallization can be performed in a short time. A preferred P ₂ O ₅ / Al ₂ O ₃ molar ratio is 0.8 to 1.2.
The silicon source and the aluminum source are mixed so that the SiO ₂ / Al ₂ O ₃ molar ratio is 0.1 to 1.2 in terms of oxide. If the SiO ₂ / Al ₂ O ₃ molar ratio is 0.1 or more, there is no shortage of the solid acid amount. When the SiO ₂ / Al ₂ O ₃ molar ratio is 1.2 or less, the crystallization speed is hardly lowered and crystallization can be performed in a short time. A preferred SiO ₂ / Al ₂ O ₃ molar ratio is 0.2 to 0.8.

Water and an aluminum source are mixed so that the H ₂ O / Al ₂ O ₃ molar ratio is 5 to 100 in terms of oxide. When an aqueous solution such as colloidal silica or phosphoric acid is used as a raw material, the amount of water in the aqueous solution must be H ₂ O. A smaller H ₂ O / Al ₂ O ₃ molar ratio is preferred because it affects the yield of the product. However, if the H ₂ O / Al ₂ O ₃ molar ratio is 5 or more, an increase in the viscosity of the reaction mixture can be suppressed. The preferred H ₂ O / Al ₂ O ₃ molar ratio is 10 to 100, more preferably 15 to 60.
The organic mineralizer (R) and the aluminum source are mixed so that the R / Al ₂ O ₃ molar ratio is 0.5 to 5 in terms of oxide. The organic mineralizer preferably has a larger R / Al ₂ O ₃ molar ratio. By setting the R / Al ₂ O ₃ molar ratio to 0.5 or more, it is easy to obtain intergrowth SAPO contained in the present adsorption / desorption agent. On the other hand, if the R / Al ₂ O ₃ molar ratio is 5 or less, a sufficient structure forming effect can be obtained. The preferred R / Al ₂ O ₃ molar ratio is 1-3.

In the production of intergrowth SAPO, the crystallization time may be shortened by adding 0.05 to 10% by weight of silicoaluminophosphate as a seed crystal to the reaction mixture. At this time, it is more effective to use the silicoaluminophosphate of the present invention as a seed crystal after pulverization.
Here, the seed crystal addition amount (% by weight) refers to the amounts of Si, P and Al of the silicon source, phosphorus source and aluminum source in the reaction mixture, respectively, and oxides (SiO ₂ , P ₂ O ₅ , Al _2). It is the weight ratio of the seed crystal to the total weight when converted as O ₃ ). When the seed crystal addition amount is 0.05% by weight or more, the effect of shortening the crystallization time can be sufficiently obtained. On the other hand, the upper limit of the seed crystal addition amount is not particularly limited, but the effect is not changed even if it exceeds 10 wt%. Therefore, a preferable seed crystal addition amount is 0.05 to 10% by weight, and more preferably 0.1 to 5% by weight.

The reaction mixture prepared as described above is placed in a sealed pressure vessel and kept at a temperature of 130 ° C. or higher and 220 ° C. or lower for 5 hours or longer and 100 hours or shorter. Thereby, the intergrowth SAPO contained in this adsorption / desorption agent can be manufactured. In order to make the composition and crystal size of the product uniform, the reaction mixture is preferably stirred during the holding.
When the crystallization temperature is high, the reaction mixture can be crystallized in a short time. A preferred crystallization temperature is 150 to 200 ° C.
The crystallized intergrowth SAPO can be separated from the crystallized mother liquor by conventional solid-liquid separation methods such as filtration, decantation, and centrifugation, washed with water if necessary, and then recovered by drying by conventional methods. Good.

The recovered dried silicoaluminophosphate contains the organic mineralizer used for crystallization in the pores. In order to use the obtained silicoaluminophosphate as a water vapor adsorbing / desorbing agent, the organic mineralizer contained can be removed by firing. The organic mineralizer may be removed by firing at a temperature of 400 to 800 ° C. in an oxygen-containing atmosphere. When firing in an atmosphere having a high oxygen concentration, the organic mineralizer burns violently, so that the structure of the silicoaluminophosphate is destroyed and the temperature of the firing furnace cannot be controlled. In such a case, it is preferable to suppress combustion of the organic mineralizer in a low oxygen atmosphere or an oxygen-free atmosphere at the initial stage of firing.

Depending on the raw material used, the intergrowth SAPO obtained as described above may contain metal cations in the raw material such as alkali metals and alkaline earth metals at the ion exchange site. Therefore, if necessary, a metal cation can be removed by acid washing or ion exchange, or a desired metal cation can be contained.

The interstitial SAPO contained in the present adsorption / desorption agent may carry an alkaline earth metal thereon.
The alkaline earth metal element is preferably at least one selected from the group consisting of magnesium (Mg), calcium (Ca), strontium (Sr), and barium (Ba), and more preferably calcium.
It is preferable that the intergrowth SAPO used for supporting the alkaline earth metal is either a proton type (H ⁺ type) continuous crystal SAPO or an ammonia type (NH ₄ ⁺ type) continuous crystal SAPO. As a result, there is a tendency that the alkaline earth metal can be more efficiently supported on the intergrowth SAPO.
In order to convert the continuous crystal SAPO into a proton type (H ⁺ type) continuous crystal SAPO, for example, the crystallized continuous SAPO may be fired at 400 ° C. or higher in the atmosphere. In addition, in order to convert the continuous crystal SAPO into the ammonia type (NH ₄ ⁺ type) continuous crystal SAPO, for example, ion exchange of the crystallized continuous SAPO with an aqueous ammonium chloride solution can be mentioned.

The raw material of the alkaline earth metal is any one selected from the group consisting of nitrates, sulfates, acetates, chlorides, complex salts, oxides and complex oxides containing alkaline earth metals supported on the intergrowth SAPO, and these Mixtures can be used, preferably nitrates or acetates.
As long as the alkaline earth metal is supported, any method can be selected as the supporting method. Examples of the loading method include ion exchange method, impregnation loading method, evaporation to dryness method, precipitation loading method or physical mixing method, and the amount of alkaline earth metal supported on the intergrowth SAPO is easy to control. The supporting method is preferably either an impregnation supporting method or an evaporation to dryness method.

These raw materials for alkaline earth metals may be used in an amount corresponding to the target loading amount. For example, when the alkaline earth metal is calcium, the amount of calcium is 0.1% by weight or more, further 0.2% by weight or more, and further 0.4% by weight or more with respect to the weight of the intergrowth SAPO. Can be mentioned. On the other hand, the amount of calcium relative to the weight of the intergrowth SAPO is 2.5% by weight or less, further 2% by weight or less, and further 1.5% by weight or less. When the alkaline earth metal is other than calcium, the alkaline earth metal in the raw material of the alkaline earth metal has an amount equivalent to the amount of substance (mol) corresponding to the above calcium amount (% by weight). That is, the raw material may be used.

The silicoaluminophosphate having the CHA structure and AEI structure of the present invention (continuous crystal silicoaluminophosphate) is a nitrogen oxide reduction catalyst, preferably a selective catalytic reduction catalyst of nitrogen oxide (hereinafter referred to as “selective catalytic reduction catalyst”). SCR catalyst "). The intergrowth silicoaluminophosphate of the present invention can be used as it is as a nitrogen oxide reduction catalyst, but can also be used by adhering to a catalyst carrier such as a honeycomb.

By using the intergrowth silicoaluminophosphate of the present invention as a nitrogen oxide reduction catalyst or SCR catalyst (hereinafter referred to as “nitrogen oxide reduction catalyst etc.”), it is exposed to an atmosphere containing moisture. Thus, a nitrogen oxide reduction catalyst or the like having a small change in the nitrogen oxide reduction rate before and after being formed. The intergrowth silicoaluminophosphate of the present invention has, for example, a nitrogen oxide reduction rate after hydration treatment relative to a nitrogen oxide reduction rate before hydration treatment (hereinafter referred to as “hydration reduction maintenance rate”). For example, the hydration reduction maintenance rate at 500 ° C. is 90% or more, the hydration reduction maintenance rate at 300 ° C. is 85% or more, the hydration reduction maintenance rate at 200 ° C. is 85% or more, and 150 ° C. It is mentioned that the hydration reduction maintenance rate in is 75% or more.

Here, the hydration treatment is a treatment in which silicoaluminophosphate is exposed to an atmosphere containing moisture, and there is no generalized or standardized condition. An example of the hydration treatment is a treatment in which a continuous silicoaluminophosphate is left standing for 1 day or more and 100 days or less in a saturated water vapor atmosphere of 60 ° C. or higher and 90 ° C. or lower.
When the intergrowth silicoaluminophosphate of the present invention is used as a nitrogen oxide reduction catalyst or the like, in addition to the small change in the nitrogen oxide reduction rate before and after being exposed to an atmosphere containing moisture, it is exposed to high temperatures. In this case, it is preferable that the nitrogen oxide reduction rate is high even when exposed to a high temperature containing moisture.

Therefore, the nitrogen oxide reduction rate after the endurance treatment of the intergrowth silicoaluminophosphate of the present invention is, for example, 70% or more at 500 ° C. In particular, the intergrowth silicoaluminophosphate of the present invention preferably has a high nitrogen oxide reduction rate after endurance treatment at low temperatures, and the nitrogen oxide reduction rate after endurance treatment is 85% or more at 300 ° C. Yes, it may be 80% or more at 200 ° C. Further, the intergrowth silicoaluminophosphate of the present invention has a high nitrogen oxide reduction rate at a lower temperature. For example, the nitrogen oxide reduction rate at 150 ° C. is 65% or more, and more than 70%. Furthermore, it is mentioned that it is 72% or more.

Here, the durability treatment is a treatment in which the intergrowth silicoalumino salt is exposed to a high temperature, that is, a state equivalent to a state after using the intergrowth silicoaluminophosphate as a nitrogen oxide reduction catalyst for a long time at a high temperature. It is a process to make. There is no generalized or standardized condition for the durability treatment. As the endurance treatment, for example, interstitial silicoaluminophosphate is added at 800 ° C. or more and 1000 ° C. or less for 1 hour or more and 24 hours or less under the flow of gas containing 10% by volume or more and 20% by volume or less of water vapor. It can be mentioned that the treatment is carried out by standing.

Here, the nitrogen oxide reduction rate refers to the concentration of nitrogen oxides in the processing gas before the contact when the processing gas containing nitrogen oxides is brought into contact with the nitrogen oxide reduction catalyst or the like. This is the concentration of nitrogen oxides in the reduced process gas. This can be obtained by the following equation (3).

Nitrogen oxide reduction rate (%)
= {1- (nitrogen oxide concentration in the processing gas after contact / nitrogen oxide concentration in the processing gas before contact)} × 100 (3)

There is no generalized or standardized condition for the method for evaluating the nitrogen oxide reduction rate of the SCR catalyst. As an evaluation method of the nitrogen oxide reduction rate of the SCR catalyst, for example, the method shown in the examples, or a gas mixture containing nitrogen oxide and ammonia in a volume ratio of 1: 1 is circulated through the catalyst. As a result, the nitrogen oxide in the mixed gas is reduced, the concentration of nitrogen oxide in the mixed gas before and after circulation is measured, and the above formula (3) is obtained.
In the case of this SCR catalytic reaction, ammonia is used as a reducing agent. Therefore, the nitrogen oxide reduction rate in this case is a value of the nitrogen oxide reduction rate as a so-called ammonia SCR catalyst.

The intergrowth silicoaluminophosphate of the present invention shows little reduction in nitrogen oxide reduction rate even when exposed to an atmosphere containing moisture. Therefore, the nitrogen oxide reduction catalyst composed of the continuous crystal silicoaluminophosphate of the present invention can be used, for example, in an exhaust gas treatment system such as factory exhaust gas or automobile exhaust gas.

Next, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.

(Measurement of composition and copper content)
The composition analysis was performed by inductively coupled plasma emission spectrometry (ICP method). That is, the sample was dissolved in a mixed solution of hydrofluoric acid and nitric acid to prepare a measurement solution. The composition of the sample was measured by measuring the obtained measurement solution using a general inductively coupled plasma emission spectrometer (trade name: OPTIMA 3000 DV, manufactured by PERKIN ELMER), and the copper content was determined.

(Measurement of average crystal grain size)
A general scanning electron microscope (trade name: JSM-6390LV, manufactured by JEOL Ltd.) was used, and the sample was observed with a scanning electron microscope (hereinafter referred to as “SEM”). The magnification of SEM observation was 1000 to 2000 times. From the SEM image of the sample obtained by SEM observation, 150 crystal particles were arbitrarily selected and their sizes were measured. The average value of the measured values obtained was determined and used as the average crystal grain size of the sample.

(Powder X-ray diffraction measurement)
A general X-ray diffractometer (trade name: MXP-3, manufactured by Mac Science Co., Ltd.) was used to measure the X-ray diffraction of the sample. A CuKα ray (λ = 1.5405 mm) is used as the radiation source, the measurement mode is a step scan, the scan condition is a step width of 0.02 °, the measurement time is 1 second, and the measurement range is 2θ to 5 ° to 40 °. Measured in range.
Each peak intensity of the powder X-ray diffraction pattern of the obtained sample was determined as a relative intensity with respect to a peak intensity with an interplanar spacing of 9.30 ± 0.15 mm.
Further, using the DIFFaX program (v1.813), the obtained X-ray diffraction pattern was analyzed to obtain the intergrowth ratio of the sample.

(Measurement of solid acid amount)
The solid acid amount of the sample was measured by the NH ₃ -TPD method shown below.
Prior to measurement, the sample was pressure-molded, pulverized, and sized to 20-30 mesh. 0.1 g of the sized sample was weighed and charged into a fixed-bed atmospheric pressure reaction tube (hereinafter simply referred to as “reaction tube”).
This was heated to 500 ° C. while flowing helium gas through the reaction tube filled with the sample. Thereby, the sample and helium gas were brought into contact. After holding at 500 ° C. for 1 hour, the reaction tube filled with the sample was cooled to 100 ° C.

After cooling, while maintaining the temperature of the reaction tube filled with the sample at 100 ° C., an ammonia-helium mixed gas containing 10% by volume of ammonia was allowed to flow therethrough at a flow rate of 60 mL / min for 1 hour. As a result, ammonia was adsorbed on the sample. After ammonia adsorption to the sample, the ammonia-helium mixed gas was stopped, and instead, helium gas was allowed to flow at 60 mL / min for 1 hour. Thereby, ammonia gas remaining in the atmosphere of the reaction tube, that is, ammonia not adsorbed on the sample was removed from the reaction tube.
Thereafter, the sample was heated from 100 ° C. to 700 ° C. at a rate of 10 ° C./min while flowing helium gas at a flow rate of 60 mL / min. Thereby, ammonia adsorbed on the sample was desorbed from the sample. Ammonia desorbed from the sample was continuously quantified by a gas chromatograph equipped with a thermal conductivity detector (TCD), thereby obtaining a desorption spectrum of ammonia.

In the obtained desorption spectrum, a peak derived from desorption of ammonia by physically adsorbing a desorption peak having a peak top at a desorption temperature of 100 ° C. or higher and lower than 250 ° C. (hereinafter referred to as “physical adsorption peak”). The desorption peak having a peak top at a desorption temperature of 250 ° C. or higher and 450 ° C. or lower was regarded as a peak derived from the solid acid of the sample (hereinafter referred to as “solid acid peak”).
The peak area of the solid acid peak in the desorption spectrum was obtained, and the peak area of the NH ₃ -TPD peak of a gas whose ammonia amount (mmol) was measured in advance (known as 30 mL of 10 vol% ammonia-helium mixed gas). The ratio of was calculated. Thus, the ammonia desorption amount (mmol) corresponding to the solid acid peak was determined, and the solid acid amount of the sample was determined by the following equation.

Sample solid acid content (mmol / g)
= Ammonia desorption amount (mmol) corresponding to the solid acid peak
Silicoaluminophosphate mass (g) having / CHA structure and AEI structure

(Measurement of BET surface area)
The BET surface area of the sample was measured using a general surface area measuring device (trade name: OMISORP 360CX type, manufactured by Coulter). The sample was pretreated at 350 ° C. for 2 hours under vacuum. After weighing about 0.1 g of the pretreated sample, the BET surface area was calculated from the nitrogen adsorption amount in the range of 0.01 to 0.05 relative pressure of the nitrogen adsorption isotherm of the sample at the liquid nitrogen temperature.

(Measurement method of nitrogen oxide reduction rate)
The nitrogen oxide reduction rate of the sample was measured by the ammonia SCR method shown below.
Prior to measurement, the sample was pressure-molded, pulverized, and then sized to 12 to 20 mesh. 1.5 mL of the sized sample was weighed and filled into a reaction tube to obtain a nitrogen oxide reduction catalyst. Then, the process gas which consists of the following compositions containing nitrogen oxide was distribute | circulated through the said reaction tube at the temperature in any one of 150 degreeC, 200 degreeC, 300 degreeC, or 500 degreeC. The other conditions were measured at a processing gas flow rate of 1.5 L / min and a space velocity (SV) of 60,000 hr ⁻¹ .

Process gas composition NO 200ppm
NH ₃ 200ppm

O

₂ 10% by volume
H ₂ O 3% by volume
Remaining N ₂

The nitrogen oxide concentration (ppm) in the processing gas after the sample flow is obtained with respect to the nitrogen oxide concentration (200 ppm) in the processing gas passed through the reaction tube, and the nitrogen oxide reduction rate is calculated according to the above equation (2). Asked.

Example 1
(Preparation of silicoaluminophosphate)
1690 g of water, 559 g of 85% phosphoric acid aqueous solution (special grade reagent, manufactured by Kishida Chemical), 284 g of 30% colloidal silica (ST-N30, manufactured by Nissan Chemical), triethylamine (hereinafter referred to as “TEA”; special grade reagent, manufactured by Kishida Chemical) 744 g and 77% pseudo boehmite (Pural SB, manufactured by Sasol) 322 g were mixed to prepare a reaction mixture having the following composition.

P ₂ O ₅ / Al ₂ O ₃ = 1.0
SiO ₂ / Al ₂ O ₃ = 0.6
H ₂ O / Al ₂ O ₃ = 50
TEA / Al ₂ O ₃ = 3

This reaction mixture was placed in a 4 L stainless steel sealed pressure vessel and kept at 180 ° C. for 69 hours while stirring at 270 rpm to crystallize it to obtain a product.
The obtained product was filtered, washed with water, and then dried in the atmosphere at 110 ° C. overnight. The product after drying was calcined in air at 600 ° C. for 2 hours.
Table 3 shows the interplanar spacing value (d value) and relative intensity of the product after firing obtained from the powder X-ray diffraction pattern. In the table, only diffraction peaks having a relative intensity of 2% or more are shown.

The resulting silicoaluminophosphate has a continuous crystal ratio of 60% (CHA / AEI = 0.667) in the AEI structure, and the composition is a continuous crystal silicoaluminophosphate represented by the following formula. It was.

(Si _0.09 Al _0.49 P _0.42 ) O ₂

Further, the average particle diameter of the intergrowth silicoaluminophosphate was 4.3 μm, the amount of solid acid was 0.91 mmol / g, and the BET surface area was 722 m ² / g.

(Production of nitrogen oxide reduction catalyst)
The obtained continuous crystal silicoaluminophosphate was calcined at 600 ° C. for 2 hours. 0.46 g of copper nitrate trihydrate (primary reagent, manufactured by Kishida Chemical Co., Ltd.) was dissolved in 2.9 g of pure water to obtain an aqueous copper nitrate solution. The entire amount of the copper nitrate aqueous solution obtained was added dropwise to 7.5 g of the baked sample, and then kneaded in a mortar for 10 minutes.
The kneaded sample was dried at 110 ° C. overnight and then calcined in the atmosphere at 500 ° C. for 1 hour to obtain a copper-containing intergrowth silicoaluminophosphate. The copper content of the obtained copper-containing intergrowth silicoaluminophosphate was 1.6% by weight.

(Hydration treatment)
5 g of the obtained copper-containing intergranular silicoaluminophosphate was weighed in a petri dish and placed in a desiccator containing pure water at the bottom, and the desiccator was sealed. By placing the desiccator in a dryer maintained at 80 ° C., the copper-containing continuous crystal silicoaluminophosphate was placed in an atmosphere of a saturated water vapor concentration (291 g / m ³ ) at 80 ° C. The copper-containing intergranular silicoaluminophosphate was hydrated by allowing it to stand in the atmosphere for 8 days, 20 days, and 80 days.
Endurance treatment of copper-containing intergranular silicoaluminophosphate after firing (ie, before hydration) and copper-containing intergranular silicoaluminophosphate after hydration treatment in each period under the following conditions Was given.

Process gas composition H ₂ O 10% by volume
The rest Air
Process gas flow rate 0.3 l / min Process gas / catalyst volume ratio 100 / min Catalyst temperature 900 ° C (Temperature increase rate 10 ° C / min)
Space velocity 6,000hr ^-1
Processing time 1 hour (900 ° C holding time)

After the endurance treatment, the nitrogen oxide reduction rate and the hydration reduction maintenance rate at low temperatures were evaluated at 150 ° C., 200 ° C., and 300 ° C., respectively. The results are shown in Table 4.

From Table 4, it was confirmed that the nitrogen oxide reduction rate after firing was 90% or more at 300 ° C., and that the intergrowth silicoaluminophosphate of the present invention had a high nitrogen oxide reduction rate at low temperatures. In particular, the nitrogen oxide reduction rate after firing is 85% or higher at 200 ° C. and 70% or higher at 150 ° C., and the intergrowth silicoaluminophosphate of the present invention has a lower temperature of 200 ° C. or lower, more preferably 150 ° C. or lower. Even below, it was confirmed that it has a high nitrogen oxide reduction rate.
Furthermore, the nitrogen oxide reduction rate at each temperature is 90% or more at 300 ° C., 80% or more at 200 ° C., and 66% or more at 150 ° C. in the entire period after hydration after firing. It was confirmed that the intergranular silicoaluminophosphate has a high nitrogen oxide reduction rate even when exposed to an atmosphere containing water for a long time.

Moreover, the hydration reduction maintenance rate at the time of performing the hydration process for 8 days and 20 days was nearly 100% at any temperature. From this, it was confirmed that the silicoaluminophosphate of the present invention becomes a nitrogen oxide reduction catalyst or the like in which the fluctuation of the nitrogen oxide reduction rate hardly occurs from the initial state.
Furthermore, even when the hydration treatment is performed for 80 days, the hydration reduction maintenance rate at 300 ° C. and 200 ° C. is nearly 100%, and the nitrogen oxide reduction rate does not decrease. The sum reduction maintenance rate was 90% or more. From this, it was confirmed that the intergrowth silicoaluminophosphate of the present invention maintained a high nitrogen oxide reduction rate not only at a low temperature of 200 ° C. or lower but also at a lower temperature of 150 ° C. or lower.

Example 2
(Production of nitrogen oxide reduction catalyst)
A continuous crystal silicoaluminophosphate was obtained in the same manner as in Example 1. The obtained continuous crystal silicoaluminophosphate was calcined at 600 ° C. for 2 hours. 10.0 g of the baked sample was weighed and dispersed in an aqueous copper acetate solution to obtain a slurry. The resulting slurry was adjusted to pH 7.5, and this was stirred at room temperature for 20 hours for ion exchange.
The aqueous solution of copper acetate was prepared by dissolving 1.01 g of copper acetate (II) monohydrate (primary reagent, manufactured by Kishida Chemical Co., Ltd.) in 100 g of pure water, and 25% aqueous ammonia was used for pH adjustment. (Special reagent grade, manufactured by Kishida Chemical) was used.
The slurry after ion exchange was filtered, washed, and dried at 110 ° C. overnight to obtain a copper-containing intergrowth silicoaluminophosphate. The copper content of the obtained copper-containing continuous crystal silicoaluminophosphate was 2.7% by weight.

Example 3
(Production of nitrogen oxide reduction catalyst)
A continuous crystal silicoaluminophosphate was obtained in the same manner as in Example 1. The obtained continuous crystal silicoaluminophosphate was calcined at 600 ° C. for 2 hours. 0.98 g of copper nitrate trihydrate was dissolved in 2.9 g of pure water to obtain an aqueous copper nitrate solution. The entire amount of the copper nitrate aqueous solution obtained was added dropwise to 7.5 g of the baked sample, and then kneaded in a mortar for 10 minutes.
The kneaded intergranular silicoaluminophosphate was dried at 110 ° C. overnight and then fired at 500 ° C. for 1 hour in an air atmosphere to obtain a copper-containing silicoaluminophosphate. The copper content of the obtained copper-containing continuous crystal silicoaluminophosphate was 3.4% by weight.

Example 4
(Preparation of silicoaluminophosphate)
1698 g of water, 559 g of 85% phosphoric acid aqueous solution, 284 g of 30% colloidal silica, 736 g of triethylamine, 322 g of 77% pseudoboehmite, and 4.2 g of seed crystals were mixed to prepare a reaction mixture having the following composition. The seed crystal used was a continuous crystal silicoaluminophosphate obtained in Example 1 that was wet-ground by a ball mill for 1 hour.

P ₂ O ₅ / Al ₂ O ₃ = 1.0
SiO ₂ / Al ₂ O ₃ = 0.6
H ₂ O / Al ₂ O ₃ = 50
TEA / Al ₂ O ₃ = 3
0.5% by weight of seed crystals

This reaction mixture was placed in a 4 L stainless steel sealed pressure vessel and kept at 180 ° C. for 64 hours while stirring at 270 rpm, and crystallized to obtain a product.
The obtained product was filtered, washed with water, and then dried in the atmosphere at 110 ° C. overnight. The product after drying was calcined in air at 600 ° C. for 2 hours.
Table 5 shows the interplanar spacing value (d value) and relative intensity obtained from the powder X-ray diffraction pattern of the product after firing. In the table, only diffraction peaks having a relative intensity of 2% or more are shown.

The resulting silicoaluminophosphate had a continuous crystal ratio of 65% (CHA / AEI = 0.538) in the AEI structure, and the composition was a continuous crystal silicoaluminophosphate represented by the following formula. It was.
(Si _0.08 Al _0.50 P _0.42 ) O ₂
Moreover, the average particle diameter of the said continuous crystal silicoaluminophosphate was 1.2 micrometers, the amount of solid acids was 0.80 mmol / g, and the BET surface area was 741 m < ² > / g.

(Production of nitrogen oxide reduction catalyst)
The obtained continuous crystal silicoaluminophosphate was calcined at 600 ° C. for 2 hours. 0.37 g of copper nitrate trihydrate was dissolved in 2.9 g of pure water to obtain an aqueous copper nitrate solution. The entire amount of the copper nitrate aqueous solution obtained was added dropwise to 7.5 g of the baked sample, and then kneaded in a mortar for 10 minutes.
The kneaded intergranular silicoaluminophosphate was dried at 110 ° C. overnight and then fired in an air atmosphere at 500 ° C. for 1 hour to obtain a copper-containing intergranular silicoaluminophosphate. The copper content of the obtained copper-containing continuous crystal silicoaluminophosphate was 1.3% by weight.

Example 5
(Preparation of silicoaluminophosphate)
29.4 g of water, 8.9 g of 85% phosphoric acid aqueous solution, 0.98 g of 30% colloidal silica, 11.7 g of triethylamine, 5.1 g of 77% pseudoboehmite, and 0.07 g of seed crystals were mixed. A reaction mixture was prepared. The seed crystal used was a continuous crystal silicoaluminophosphate obtained in Example 1 that was wet-ground by a ball mill for 1 hour.

P ₂ O ₅ / Al ₂ O ₃ = 1.0
_{_{_{SiO 2 / Al 2 O 3 =}}} 0.13
H ₂ O / Al ₂ O ₃ = 50
TEA / Al ₂ O ₃ = 3
0.6% by weight of seed crystals

This reaction mixture was put into an 80 ml stainless steel sealed pressure vessel, kept at 180 ° C. for 63 hours while rotating at 55 rpm around the horizontal axis, and crystallized to obtain a product.
The obtained product was filtered, washed with water, and then dried in the atmosphere at 110 ° C. overnight. The product after drying was calcined in air at 600 ° C. for 2 hours.
Table 6 shows the spacing value (d value) and the relative intensity obtained from the powder X-ray diffraction pattern of the product after firing. In the table, only diffraction peaks having a relative intensity of 2% or more are shown.

The resulting silicoaluminophosphate has a continuous crystal ratio of 60% (CHA / AEI = 0.667) in the AEI structure, and the composition is a continuous crystal silicoaluminophosphate represented by the following formula. It was.
(Si _0.06 Al _0.50 P _0.44 ) O ₂
Moreover, the average particle diameter of the said continuous crystal silicoaluminophosphate was 1.4 micrometers, the amount of solid acids was 0.59 mmol / g, and the BET surface area was 749 m < ² > / g.

(Production of nitrogen oxide reduction catalyst)
The obtained continuous crystal silicoaluminophosphate was calcined at 600 ° C. for 2 hours. 0.37 g of copper nitrate trihydrate was dissolved in 2.9 g of pure water to obtain an aqueous copper nitrate solution. The entire amount of the copper nitrate aqueous solution obtained was added dropwise to 7.5 g of the baked sample, and then kneaded in a mortar for 10 minutes.
The kneaded intergranular silicoaluminophosphate was dried at 110 ° C. overnight and then fired at 500 ° C. for 1 hour in an air atmosphere to obtain a copper-containing silicoaluminophosphate. The copper content of the obtained copper-containing silicoaluminophosphate was 1.3% by weight.

Example 6
(Production of nitrogen oxide reduction catalyst)
A continuous crystal silicoaluminophosphate was obtained in the same manner as in Example 1. The obtained continuous crystal silicoaluminophosphate was calcined at 600 ° C. for 2 hours. 10.0 g of the calcined sample was weighed and dispersed in an aqueous copper nitrate solution to obtain a slurry. The obtained slurry was adjusted to pH 7.0, and ion exchange was performed by stirring the slurry at room temperature for 2 hours.
The aqueous copper nitrate solution used was a solution of 0.63 g of copper (II) nitrate monohydrate in 100 g of pure water, and 25% aqueous ammonia was used for pH adjustment.
The slurry after ion exchange was filtered, washed, and dried at 110 ° C. overnight to obtain a copper-containing intergrowth silicoaluminophosphate. The copper content of the obtained copper-containing silicoaluminophosphate was 0.3% by weight.

Comparative Example 1
(Preparation of silicoaluminophosphate)
244 g of water, 279 g of 85% aqueous phosphoric acid solution, 135 g of 30% colloidal silica, 1159 g of 35% tetraethylammonium hydroxide (TEAOH; industrial, manufactured by Alpha-Acer) and 183 g of 77% pseudoboehmite were mixed together. Prepared.

_{_{_{_{P 2 O 5 / Al 2 O}}}} 3 = 0.88
SiO ₂ / Al ₂ O ₃ = 0.5
H ₂ O / Al ₂ O ₃ = 50
TEAOH / Al ₂ O ₃ = 2

The reaction mixture was placed in a 4 L stainless steel sealed pressure vessel and held at 200 ° C. for 92 hours with stirring at 270 rpm.
The product was filtered, washed with water and then dried overnight at 110 ° C. in air. The product after drying was calcined in air at 600 ° C. for 2 hours.
Table 7 shows the interplanar spacing value (d value) and relative intensity obtained from the powder X-ray diffraction pattern of the product after firing. In the table, only diffraction peaks having a relative intensity of 2% or more are shown.

The resulting silicoaluminophosphate had a continuous crystal ratio of 10% (CHA / AEI = 0.111) for the AEI structure, and a continuous crystal silicoaluminophosphate represented by the following formula.
(Si _0.12 Al _0.49 P _0.39 ) O ₂
Moreover, the average particle diameter of the said continuous crystal silicoaluminophosphate was 0.8 micrometer, and the amount of solid acids was 1.15 mmol / g.

(Production of nitrogen oxide reduction catalyst)
The obtained continuous crystal silicoaluminophosphate was calcined at 600 ° C. for 2 hours. An aqueous copper nitrate solution in which 0.46 g of copper nitrate trihydrate was dissolved in 2.9 g of pure water was dropped onto 7.5 g of the calcined sample, and then kneaded in a mortar for 10 minutes.
The kneaded intergranular silicoaluminophosphate was dried at 110 ° C. overnight and then fired in an air atmosphere at 500 ° C. for 1 hour to obtain a copper-containing intergranular silicoaluminophosphate. The copper content of the obtained copper-containing intergrowth silicoaluminophosphate was 1.6% by weight.

(Hydration treatment)
The obtained copper-containing intergranular silicoaluminophosphate was hydrated in the same manner as in Example 1 except that the standing period was 80 days. After the hydration treatment, the copper-containing silicoaluminophosphate obtained by endurance treatment in the same manner as in Example 1 and the copper-containing intergrowth silicoaluminophosphate after firing (that is, before the endurance treatment) After the application, the nitrogen oxide reduction rate was evaluated at each temperature of 150 ° C., 200 ° C., 300 ° C., and 500 ° C. The results are shown in Table 8.

From Table 8, the nitrogen oxide reduction rate of Comparative Example 1 at a high temperature of 500 ° C. was higher than that of Example 1. However, after the hydration treatment for 80 days, the hydration reduction maintenance rate of Example 1 was 100%, whereas that of Comparative Example 1 was 77%. From this, it can be seen that the intergrowth silicoaluminophosphate of the present invention has less change in the nitrogen oxide reduction rate at a high temperature of 500 ° C. or higher, compared to intergrowth silicoaluminophosphate containing a large amount of CHA structure. It was.
Moreover, in the nitrogen oxide reduction rates of 300 ° C. and 200 ° C., after firing, both Example 1 and Comparative Example 1 show a nitrogen oxide reduction rate of 90% or more, and have equivalent nitrogen oxide reduction characteristics. Was confirmed. However, the hydration reduction maintenance rate of Comparative Example 1 after the hydration treatment for 80 days was 83%, which was lower than the hydration reduction maintenance rate of Example 1. As a result, the intergrowth silicoaluminophosphate of the present invention has a nitrogen oxide reduction rate even at a low temperature of 300 ° C. or less, and even 200 ° C. or less, compared with the intergrowth silicoaluminophosphate containing many CHA structures. It turned out that there was little change of.

Furthermore, at a nitrogen oxide reduction rate of 150 ° C., after firing, Example 1 was 74%, while Comparative Example 1 was 70%. Accordingly, at a lower temperature of 150 ° C. or lower, the intergrowth silicoaluminophosphate of the present invention has a higher nitrogen oxide reduction rate than intergrowth silicoaluminophosphate containing a large amount of CHA structure. It was confirmed that Further, the hydration reduction maintenance rate at 150 ° C. is 90% or more in Example 1, whereas it is 30% in Comparative Example 1, and the intergrowth silicoaluminophosphate of the present invention has a continuous CHA structure. It was confirmed that the hydration reduction maintenance rate was 3 times or more compared with the crystalline silicoaluminophosphate. Accordingly, it was confirmed that the intergrowth silicoaluminophosphate of the present invention has nitrogen oxide reduction characteristics with little change in nitrogen oxide reduction rate at a lower temperature of 150 ° C. or lower.

Comparative Example 2
(Preparation of silicoaluminophosphate)
64.3 g of water, 18.3 g of 85% phosphoric acid aqueous solution, 30% colloidal silica (6.9 g, N-ethyldiisopropylamine (hereinafter referred to as “EDIPA”; special grade reagent, manufactured by Kishida Chemical), and 11.7 g of 77% pseudo boehmite was mixed to prepare a reaction mixture having the following composition.

P ₂ O ₅ / Al ₂ O ₃ = 0.9
SiO ₂ / Al ₂ O ₃ = 0.4
H ₂ O / Al ₂ O ₃ = 50
EDIPA / Al ₂ O ₃ = 1.6

The reaction mixture was placed in an 80 ml stainless steel sealed pressure vessel and kept at 160 ° C. for 91 hours while rotating at 55 rpm around the horizontal axis.
The product was filtered, washed with water and then dried overnight at 110 ° C. in air. The product after drying was calcined in air at 600 ° C. for 2 hours.
Table 9 shows the interplanar spacing value (d value) and relative intensity obtained from the powder X-ray diffraction pattern of the product after firing. In the table, only diffraction peaks having a relative intensity of 2% or more are shown.

The resulting silicoaluminophosphate had a continuous crystal ratio of 100% (CHA / AEI = 0) in the AEI structure, and a silicoaluminophosphate having only the AEI structure in the structure. Further, the composition of the silicoaluminophosphate was represented by the following formula.
(Si _0.12 Al _0.50 P _0.39 ) O ₂
Further, the crystalline shape of the silicoaluminophosphate was an indefinite shape such as a columnar shape or a plate shape, and was a particle having a long side direction of about 1 μm, and the solid acid amount was 0.33 mmol / g.

(Production of nitrogen oxide reduction catalyst)
The obtained silicoaluminophosphate was calcined at 600 ° C. for 2 hours. An aqueous copper nitrate solution in which 0.46 g of copper nitrate trihydrate was dissolved in 2.9 g of pure water was dropped onto 7.5 g of the calcined sample, and then kneaded in a mortar for 10 minutes.
After the kneaded silicoaluminophosphate was dried at 110 ° C. overnight, firing was performed at 500 ° C. for 1 hour in an air atmosphere to obtain a copper-containing silicoaluminophosphate. The copper content of the obtained copper-containing silicoaluminophosphate was 1.6% by weight.

(Heat resistance evaluation)
The same durability treatment as in Example 1 was performed on the copper-containing intergrowth silicoaluminophosphates of Examples 1, 2, 4 and Comparative Example 1 and the copper-containing silicoaluminophosphate of Comparative Example 2. The nitrogen oxide reduction rate of these samples before and after the durability treatment was measured. The results are shown in Table 10.

From Table 10, the intergrowth silicoaluminophosphate of the examples has a nitrogen oxide reduction rate of 65% or more before endurance treatment at any of 150 ° C., 200 ° C., 300 ° C., and 500 ° C., It was confirmed that the nitrogen oxide reduction rate after the durability treatment was 70% or more, both having high nitrogen oxide reduction characteristics.
In particular, it was confirmed that the copper-containing intergrowth silicoaluminophosphates of the examples showed a high value of the nitrogen oxide reduction rate at 150 ° C. exceeding 70% after the durability treatment.
Further, the copper-containing intergrowth silicoaluminophosphate of Example 1 has the same amount of copper as the intergrowth silicoaluminophosphate of Comparative Example 1. However, the nitrogen oxide reduction rate of Example 1 was higher than that of Comparative Example 1 regardless of the endurance treatment. Thus, the intergrowth silicoaluminophosphate of the present invention exhibits a higher nitrogen oxide reduction rate than the intergrowth silicoaluminophosphate containing a large amount of CHA structure, particularly the nitrogen oxide reduction rate at a low temperature of 150 ° C. Was confirmed to be high.

Hereinafter, the present adsorbent / desorbent will be described more specifically by experimental examples, but the present adsorbent / desorbent is not limited to this.

(Intergrowth ratio)
The intergrowth ratio (CHA / AEI ratio) of the sample was determined by comparing the XRD simulation pattern using the DIFFaX program (v1.813) distributed by the International Zeolite Society and the XRD pattern of the sample.

(Crystal structure retention)
About 0.5 g of a sample was weighed into a petri dish. This was stored for 8 days in saturated steam at 80 ° C. in a desiccator containing water kept at 80 ° C. After storage for 8 days, baking was performed at 600 ° C. for 1 hour, and X-ray diffraction was evaluated.
As for the crystal structure retention rate, the sum of main peak intensities in the XRD pattern measured using the copper Kα ray as a radiation source for the sample before and after the storage was obtained. From the total, the crystal structure retention rate was determined by the following formula. In Experimental Examples 1, 2, and 3, four peaks at 2θ = 16.1 °, 19.1 °, 20.7 °, and 26.1 ° were set as main peaks. On the other hand, in Comparative Experimental Example 1, four peaks at 2θ = 16.1 °, 17.8 °, 20.8 °, and 25.1 ° were set as main peaks.
Crystal structure retention rate (%) = (peak intensity after storage / peak intensity before storage) × 100

(Measurement of solid acid amount)
The solid acid amount of the sample was measured by the NH ₃ -TPD method shown below.
Prior to measurement, the sample was pressure-molded, pulverized, and sized to 20-30 mesh. 0.1 g of the sized sample was weighed and filled into a fixed bed normal pressure flow type reaction tube (hereinafter simply referred to as “reaction tube”).
This was heated to 500 ° C. while flowing helium gas through the reaction tube filled with the sample. Thereby, the sample and helium gas were brought into contact. After holding at 500 ° C. for 1 hour, the reaction tube filled with the sample was cooled to 100 ° C.

After cooling, while maintaining the temperature of the reaction tube filled with the sample at 100 ° C., an ammonia-helium mixed gas containing 10% by volume of ammonia was passed at a flow rate of 60 mL / min for 1 hour. As a result, ammonia was adsorbed on the sample. After ammonia adsorption to the sample, the ammonia-helium mixed gas was stopped, and instead, helium gas was passed at 60 mL / min for 1 hour. Thereby, ammonia gas remaining in the atmosphere of the reaction tube, that is, ammonia that was not adsorbed on the sample was removed from the reaction tube.
Thereafter, the temperature of the sample was increased from 100 ° C. to 700 ° C. at a temperature increase rate of 10 ° C./min while flowing helium gas at a flow rate of 60 mL / min. Thereby, ammonia adsorbed on the sample was desorbed from the sample. Ammonia desorbed from the sample was continuously quantified by a gas chromatograph equipped with a thermal conductivity detector (TCD), thereby obtaining a desorption spectrum of ammonia.

In the obtained desorption spectrum, a desorption peak having a peak top at a desorption temperature of 100 ° C. or higher and lower than 250 ° C. is a peak derived from desorption of ammonia physically adsorbed on a sample (hereinafter referred to as “physical adsorption peak”). The desorption peak having a peak top at a desorption temperature of 250 ° C. or higher and 450 ° C. or lower was regarded as a peak derived from the solid acid of the sample (hereinafter referred to as “solid acid peak”).
The peak area of the solid acid peak in the desorption spectrum was obtained, and the NH ₃ -TPD peak of a gas having a known ammonia amount (mmol) (0.25 mL of 10 vol% ammonia-helium mixed gas) was measured in advance. The ratio with the area was determined. Thus, the ammonia desorption amount (mmol) corresponding to the solid acid peak was determined, and the solid acid amount of the sample was determined by the following equation.

Sample solid acid content (mmol / g)
= Ammonia desorption amount (mmol) corresponding to solid acid peak / silicoaluminophosphate mass (g)

(Evaluation of water vapor adsorption amount)
Prior to the measurement, the sample was pressure-molded, pulverized, and sized to 20-30 mesh, and pretreated at 350 ° C. for 2 hours. After the pretreatment, the water vapor adsorption amount was evaluated under the following conditions.

Apparatus: Magnetic floating balance (manufactured by Nippon Bell Co., Ltd.)
Adsorption temperature: 25 ° C
Air constant temperature: 80 ° C
Initial introduction pressure: 5 kPa

The water vapor adsorption isotherm was obtained under the above conditions, and the water vapor adsorption amount at a relative pressure of 0.05 to 0.30 was determined from this. The water vapor adsorption amount was determined as the water vapor adsorption amount (g / 100 g) with respect to 100 g of the sample.

Experimental example 1
29.4 g of water, 9.00 g of 85% phosphoric acid aqueous solution (Kishida Chemical: special grade reagent), 1.53 g of 30% colloidal silica (Nissan Chemical: ST-N30), 11.9 g of triethylamine (Kishida Chemical: special grade reagent), and 5.19 g of 77% pseudo boehmite (Sasol: Pural SB) and 0.075 g of seed crystals obtained by wet milling crystalline silicoaluminophosphate with a ball mill for 1 hour were mixed to prepare a reaction mixture having the following composition: did.

P ₂ O ₅ / Al ₂ O ₃ (molar ratio) = 1.0
SiO ₂ / Al ₂ O ₃ (molar ratio) = 0.20
H ₂ O / Al ₂ O ₃ (molar ratio) = 50
TEA / Al ₂ O ₃ (molar ratio) = 3
(TEA represents triethylamine used as an organic mineralizer.)
Seed crystal addition amount = 0.6 wt%

This reaction mixture was placed in an 80 ml stainless steel sealed pressure vessel and kept at 180 ° C. for 62 hours with stirring.
The product was filtered, washed with water, dried at 110 ° C. overnight, and then calcined at 600 ° C. for 2 hours.
For the product, the interplanar spacing value (d value) of the peak position and the relative intensity of the peak were determined from the XRD pattern obtained by an X-ray diffractometer (Mac Science: MPX3) using copper Kα rays as the radiation source. Shown in

As shown in Table 11, the spacing between 6.60 mm (diffraction angle 2θ = 13.4 °) and 5.24 mm (diffraction angle 2θ) not present in the powder X-ray diffraction pattern of SAPO-34 silicoaluminophosphate. = 16.9 °) and 4.17 ° (diffraction angle 2θ = 21.3 °) having broad peaks.
The product after drying was subjected to composition analysis using an inductively coupled plasma emission spectrometer (ICP), and had the following composition in terms of oxide.
(Si _0.055 Al _0.50 P _0.44 ) O ₂
The resulting silicoaluminophosphate had a CHA / AEI intergrowth ratio of 40/60 in terms of CHA / AEI ratio.
The crystal structure retention rate was 100%, which was a high crystal structure retention rate.

(Hydration treatment)
The obtained silicoaluminophosphate was calcined at 600 ° C. for 2 hours. As a result, the organic mineralizer was removed to obtain a proton type (H ⁺ type) silicoaluminophosphate. After baking, the silicoaluminophosphate was weighed in a 0.5 g petri dish, and placed in a desiccator containing pure water at the bottom, and then the desiccator was sealed. By placing the desiccator in a dryer maintained at 80 ° C., the silicoaluminophosphate was placed in an atmosphere of saturated water vapor concentration (291 g / m ³ ) at 80 ° C. The silicoaluminophosphate was hydrated by standing in the atmosphere for 8 days.

(Measurement of solid acid amount)
The solid acid amounts of the silicoaluminophosphate after calcination (that is, the silicoaluminophosphate before hydration treatment) and the silicoaluminophosphate after hydration treatment were measured. As a result, the solid acid amount of the silicoaluminophosphate after firing was 0.78 mmol / g, and the solid acid amount of the silicoaluminophosphate after hydration treatment was 0.54 mmol / g. The subsequent solid acid retention rate was 70%.
From the water vapor adsorption isotherm, the water vapor adsorption amount at a relative pressure of 0.05 to 0.30 was 24.3 (g / 100 g). The water vapor adsorption isotherm measured at 25 ° C. is shown in FIG.

Experimental example 2
1698 g of water, 559 g of 85% phosphoric acid aqueous solution, 284 g of 30% colloidal silica, 736 g of triethylamine, 322 g of 77% pseudo-boehmite, and 4.2 g of seed crystals obtained by wet-grinding crystalline silicoaluminophosphate with a ball mill for 1 hour are mixed. A reaction mixture of the following composition was prepared:

P ₂ O ₅ / Al ₂ O ₃ (molar ratio) = 1.0
SiO ₂ / Al ₂ O ₃ (molar ratio) = 0.6
H ₂ O / Al ₂ O ₃ (molar ratio) = 50
TEA / Al ₂ O ₃ (molar ratio) = 3
(TEA represents triethylamine used as an organic mineralizer.)
0.5% by weight of seed crystals

The reaction mixture was placed in a 4000 ml stainless steel sealed pressure vessel and held at 180 ° C. for 64 hours with stirring at 270 rpm.
The product was filtered, washed with water, dried at 110 ° C. overnight, and then calcined at 600 ° C. for 2 hours.
For the product, the interplanar spacing value (d value) of the peak position and the relative intensity of the peak were determined from the X-ray diffraction pattern obtained by a powder X-ray diffractometer (Mac Science: MPX3) using copper Kα rays as the radiation source. Table 12 shows.

As shown in Table 12, the resulting product had the characteristics of the crystalline silicoaluminophosphate of the present invention. That is, the obtained product is a broad peak that does not exist in the XRD pattern of SAPO-34 silicoaluminophosphate, with an interplanar spacing of about 6.60 mm (diffraction angle 2θ = 13.4 °), 5.24 mm. It had broad peaks in the vicinity (diffraction angle 2θ = 16.9 °) and 4.17 ° (diffraction angle 2θ = 21.3 °).
The product after drying was subjected to composition analysis using an inductively coupled plasma emission spectrometer (ICP), and had the following composition in terms of oxide.
(Si _0.08 Al _0.50 P _0.42 ) O ₂
The obtained silicoaluminophosphate had a CHA / AEI intergrowth ratio of 35/65 in CHA / AEI ratio.
The crystal structure retention rate was 100%, which was a high crystal structure retention rate.

(Measurement of solid acid amount)
The silicoaluminophosphate was calcined and hydrated by the same method as in Experimental Example 1, and the amount of the solid acid was measured. As a result, the solid acid amount of the silicoaluminophosphate after firing was 0.80 mmol / g, and the solid acid amount of the silicoaluminophosphate after hydration treatment was 0.51 mmol / g. The subsequent solid acid retention rate was 64%.
From the water vapor adsorption isotherm, the water vapor adsorption amount at a relative pressure of 0.05 to 0.30 was 22.16 (g / 100 g).

Experimental example 3
The same operation as in Experimental Example 2 was performed except that the crystallization temperature was 175 ° C.
For the product, the interplanar spacing value (d value) of the peak position and the relative intensity of the peak were determined from the X-ray diffraction pattern obtained by a powder X-ray diffractometer (Mac Science: MPX3) using copper Kα rays as the radiation source. Table 13 shows.

As shown in Table 13, the characteristics of the crystalline silicoaluminophosphate of the present invention, that is, the vicinity of 6.60 mm (diffraction angle 2θ = not present in the powder X-ray diffraction pattern of SAPO-34 silicoaluminophosphate) It had broad peaks in the vicinity of 13.4 °), 5.24 ° (diffraction angle 2θ = 16.9 °) and 4.17 ° (diffraction angle 2θ = 21.3 °).
The product after drying was subjected to composition analysis using an inductively coupled plasma emission spectrometer (ICP), and had the following composition in terms of oxide.
(Si _0.08 Al _0.50 P _0.42 ) O ₂
The resulting silicoaluminophosphate had a CHA / AEI intergrowth ratio of 40/60 in terms of CHA / AEI ratio.
The crystal structure retention rate was 83%, which was a high crystal structure retention rate.

(Measurement of solid acid amount)
The silicoaluminophosphate was calcined and hydrated by the same method as in Experimental Example 1, and the amount of the solid acid was measured. As a result, the solid acid amount of the silicoaluminophosphate after firing was 0.94 mmol / g, and the solid acid amount of the silicoaluminophosphate after hydration treatment was 0.55 mmol / g. The subsequent solid acid retention rate was 58%.
From the water vapor adsorption isotherm, the water vapor adsorption amount at a relative pressure of 0.05 to 0.30 was 20.9 (g / 100 g).

(Manufacture of calcium-supported silicoaluminophosphate)
Calcium nitrate solution in which 7.0g of dry weight silicoaluminophosphate was weighed out in dry weight and 0.38g of calcium nitrate tetrahydrate (Kishida Chemical Co., Ltd .: reagent grade) was dissolved in 2.75g of pure water. Was added dropwise thereto, and then kneaded for 10 minutes in a mortar.
The kneaded sample was dried at 110 ° C. overnight and then calcined in air at 550 ° C. for 2 hours to obtain a calcium-containing silicoaluminophosphate. The amount of calcium supported was 0.91% by weight.
From the water vapor adsorption isotherm of the calcium-supporting silicoaluminophosphate, the water vapor adsorption amount at a relative pressure of 0.05 to 0.30 was 21.8 (g / 100 g).

Comparative Experiment Example 1
244 g of water, 279 g of 85% phosphoric acid aqueous solution (Kishida Chemical: Special Grade Reagent), 135 g of 30% colloidal silica (Nissan Chemical: ST-N30), 1159 g of 35% tetraethylammonium hydroxide (Alfa Acer), 77% pseudoboehmite (Sasol: Pural SB) 183 g was mixed to prepare a reaction mixture having the following composition.

P ₂ O ₅ / Al ₂ O ₃ (molar ratio) = 0.88
SiO ₂ / Al ₂ O ₃ (molar ratio) = 0.5
H ₂ O / Al ₂ O ₃ (molar ratio) = 50
TEAOH / Al ₂ O ₃ (molar ratio) = 2

(TEAOH represents tetraethylammonium hydroxide used as an organic mineralizer.)

The reaction mixture was placed in a 4000 mL stainless steel sealed pressure vessel and held at 200 ° C. for 92 hours with stirring at 270 rpm.
The product was filtered, washed with water, dried at 110 ° C. overnight, and then calcined at 600 ° C. for 2 hours.
About the product, the lattice spacing value (d value) of the peak position and the relative intensity of the peak were obtained from the XRD pattern obtained by a powder X-ray diffractometer (Mac Science: MPX3) using copper Kα rays as the radiation source. Table 14 shows.

As shown in Table 14, SAPO-34 had a lattice spacing-relative strength characteristic.
The product after drying was subjected to composition analysis using an inductively coupled plasma emission spectrometer (ICP), and had the following composition in terms of oxide.
(Si _0.12 Al _0.49 P _0.39 ) O ₂
The crystal structure retention rate was 41%, and the crystal structure retention rate was reduced.

(Measurement of solid acid amount)
SAPO-34 was calcined and hydrated by the same method as in Experimental Example 1, and the amount of the solid acid was measured. As a result, the solid acid amount of SAPO-34 after calcination was 1.06 mmol / g, and the solid acid amount of SAPO-34 after hydration treatment was 0.42 mmol / g. The maintenance rate was 40%.
From the water vapor adsorption isotherm, the water vapor adsorption amount at a relative pressure of 0.05 to 0.30 was 15.6 (g / 100 g), which was a low adsorption amount. The water vapor adsorption isotherm measured at 25 ° C. is shown in FIG.
Compared to the water vapor adsorption isotherm of Experimental Example 1 in FIG. 3, Comparative Experimental Example 1 had a small amount of water vapor adsorption at a relative pressure of 0.05 to 0.30. From this, the silicoaluminophosphate of Experimental Example 1 has a higher crystal structure retention rate when stored in saturated steam at 80 ° C. for 8 days, and is excellent in water resistance. As a result, in the saturated steam at 80 ° C. The amount of water vapor adsorption after storage for 8 days is high.

The intergrowth silicoaluminophosphate of the present invention can be used as a nitrogen oxide reduction catalyst, particularly a nitrogen oxide reduction catalyst that selectively reduces nitrogen oxide using ammonia or the like as a reducing agent. Thus, the nitrogen oxide reduction catalyst containing the intergrowth silicoaluminophosphate of the present invention includes, for example, exhaust gas containing oxygen from internal combustion engines such as diesel engines and gasoline engines and combustion facilities. It can be used for exhaust gas treatment systems such as automobile exhaust gas and factory exhaust gas.
This adsorption / desorption agent can be used as a water vapor adsorption / desorption agent for an adsorption heat pump system, a desiccant air conditioning system, a humidity adjusting wall agent, a humidity adjusting sheet and the like.
Although the invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.
The specification, claims and drawings of Japanese Patent Application No. 2012-230882 filed on October 18, 2012 and Japanese Patent Application No. 2012-197474 filed on September 7, 2012 The entire contents of the abstract are hereby incorporated by reference as the disclosure of the specification of the present invention.

Claims

A silicoaluminophosphate having a CHA structure and an AEI structure, having at least one metal selected from the group consisting of Group VIIIB elements, Group IB elements, and Group VIIB elements of the periodic table, and the proportion of the AEI structure exceeds 50% .
The silicoaluminophosphate according to claim 1, wherein at least one metal selected from the group consisting of Group VIIIB elements, Group IB elements, and Group VIIB elements of the periodic table is copper.
A crystallization step for crystallizing a mixture containing a tertiary amine, a silicoaluminophosphate having a CHA structure and an AEI structure obtained by the crystallization step, wherein the proportion of the AEI structure exceeds 50%. The manufacturing method of the silicoaluminophosphate of Claim 1 or 2 which has a metal containing process which makes a salt contain a metal.
A method for producing a nitrogen oxide reduction catalyst using the silicoaluminophosphate according to claim 1 or 2.
A method for reducing nitrogen oxide, wherein the silicoaluminophosphate according to claim 1 or 2 is used.