JP5428540B2 - SAPO-34 having high water resistance and large particles, synthesis method thereof and use thereof - Google Patents

Description

  The present invention relates to a highly water-resistant and large-particle SAPO-34 used as a catalyst, an adsorbent, an ion exchanger and the like.

  SAPO-34 is a kind of silicoaluminophosphate zeolite represented by the structure code CHA.

  SAPO-34 is a catalyst for converting lower organic oxygen compounds such as methanol, ethanol and dimethyl ether into lower olefins such as ethylene and propylene, a catalyst for purifying nitrogen oxides in automobile exhaust gas, and a light hydrocarbon adsorption / separation agent. It is a useful zeolite.

  SAPO-34 is synthesized using various organic structure directing agents. For example, Patent Document 1 reports SAPO-34 using tetraethylammonium ions as a structure directing agent, and Patent Document 2 reports SAPO-34 using morpholine as a structure directing agent.

  SAPO-34 is known to vary greatly depending on physical properties such as particle size, durability such as water resistance, heat resistance and hot water resistance, and structure directing agent used in production costs.

  For example, SAPO-34 synthesized using tetraethylammonium ions as a structure directing agent has a small particle size, and thus it is difficult to separate solid and liquid after synthesis (Patent Document 3). For this reason, it has been reported that SAPO-34 is subjected to a separation operation by a low efficiency method called centrifugation (Patent Document 4).

  On the other hand, it has been reported that SAPO-34 having a relatively large particle size can be obtained by using morpholine as a structure directing agent (Patent Document 2). However, SAPO-34 obtained by such a method has low water resistance, and it has been reported that most of the pores disappear in 2 years in storage at room temperature after hydration after removal of the structure directing agent. (For example, Non-Patent Document 1). In the activated SAPO-34, in a moisture-containing environment (20 ° C., relative humidity 80%), a loss of catalytic activity was confirmed in only one day, and the catalytic activity after storage for 3 days was 0%. (Patent Document 5).

  Thus, conventional SAPO-34 having low water resistance removes adsorbed water (Patent Document 6), avoids contact with water as much as possible (Patent Document 7), preserves as an ammonium type (Non-Patent Document 2), etc. Special handling was necessary for deterioration caused by water.

  Furthermore, the amount of acid sites (acid amount), which is the most important physical property when SAPO-34 functions as a catalyst, adsorbent, or ion exchanger, is more durable than surface area, pore volume, X-ray diffraction intensity, etc. It is known that the nature is low. For example, SAPO-34 synthesized using tetraethylammonium ions retains a surface area of 90 to 94% and a pore volume of 81 to 93% in hot water treatment (900 ° C., relative humidity 80%, 16 hours). On the other hand, it is reported that the acid amount is reduced to 40 to 57% (Patent Document 8).

  As described above, SAPO-34 is expected to be used as a catalyst, an adsorbent, and an ion exchanger. However, SAPO-34, which has excellent water resistance and hot water resistance, and excellent solid-liquid separation, has a large particle size. It was not obtained.

Japanese Patent Publication No. 03-072010 (Example 33 etc.) Patent No. 1811353 (Example 1 etc.) Japanese Patent No. 4212287 (column [0003]) US Pat. No. 5,095,163 (Example 1) Special table 2003-501406 ([0011] column, Examples 1 and 2 etc.) Special Table 2007-503375 ([Problem] [Claim 1] etc.) World Patent No. 2005000468 (summary, claims, etc.) World Patent No. 20080081434A1 (Claims, Table 1, etc.)

J. et al. Phys. Chem. , 99, 8270-8276 (1995) (Summary, Table 1, FIG. 12, etc.) Chemical Communication, 44-45 (2003) (summary, FIG. 3 etc.)

  The present invention provides SAPO-34 having a large particle size that has high water resistance (room temperature and hot water) and is easy to separate after synthesis.

  As a result of intensive studies on SAPO-34, the present inventors have found that at least a phosphoric acid, an aluminum source not containing an alkoxide, a silica source, tetraethylammonium ions and water, and a P / Al molar ratio of 1.1 or more. SAPO-34 obtained by crystallizing a small composition at a temperature exceeding 180 ° C. at a standing temperature has high water resistance, and SAPO-34 is subjected to a saturated hydration endurance treatment (for example, 25 ° C., relative humidity 80 %, After 90 days treatment), the acid amount measured by the ammonia temperature programmed desorption method is 0.8 mmol / g or more, and the average crystal diameter is 1.0 μm or more. The invention has been completed.

  Hereinafter, SAPO-34 of the present invention will be described.

  In the SAPO-34 of the present invention, the acid amount measured by the ammonia temperature programmed desorption method is 0.8 mmol / g or more at the time of saturated hydration endurance treatment (for example, after treatment at 25 ° C., relative humidity 80%, 90 days). In particular, 1.0 mmol / g or more is preferable, and 1.2 mmol / g or more is more preferable. When the acid amount is less than 0.8 mmol / g, the characteristics as a catalyst, an adsorbent and an ion exchanger are insufficient, and special handling for water is required. In addition, the acid amount after one year of saturated hydration durability treatment is preferably 0.8 mmol / g or more, and the acid amount after two years of steam treatment is more preferably 0.8 mmol / g or more.

  In the present invention, the saturated hydration endurance treatment refers to a state after SAPO-34 after deaeration is stored for 90 days in an atmosphere of 25 ° C. and 80% relative humidity. In an atmosphere of 25 ° C and relative humidity of 80%, the degassed SAPO-34 spread in a glass dish or the like is treated in a constant temperature and humidity chamber or in a desiccator immersed in a saturated aqueous solution of ammonium chloride. it can.

  In the SAPO-34 of the present invention, the acid amount measured by the ammonia temperature-programmed desorption method is 0 at the time of hot water endurance treatment (for example, 10% by volume of steam containing 100% / min flow of wet air, 900 ° C., 1 hour). 0.7 mmol / g or more, particularly 0.9 mmol / g or more, more preferably 1.3 mmol / g or more.

  In the hot water endurance treatment in the present invention, for example, a sample is pressure-molded, pulverized and sized to 12 to 20 mesh, 1 cc of the sized sample is charged into an atmospheric pressure fixed bed flow type reaction tube, water vapor Can be implemented as a state after the temperature is raised to 900 ° C. and kept for 1 hour while flowing humid air containing 10% by volume at 100 mL / min.

  The acid amount by the ammonia temperature-programmed desorption method of the present invention is an acid amount calculated from the amount of ammonia desorbed by raising the temperature of the adsorbed ammonia at 100 ° C. or less from 100 ° C. to 700 ° C. . Specifically, an adsorbed component was removed from a sample of about 0.1 g in an inert gas (helium) at 500 ° C., and a mixed gas of 90% inert gas (helium) and 10% ammonia was added at 25 ° C. with ammonia. Adsorbed saturated, then heated to 700 ° C, and the amount of ammonia desorbed in the course of the temperature rise (excluding those desorbed in the temperature range of 25-100 ° C) was determined with a thermal conductivity detector. Measure by doing.

  The SAPO-34 of the present invention preferably has an average crystal diameter of 1.0 μm or more, more preferably 2.0 μm or more, and even more preferably 3.0 μm or more. When the average crystal diameter is less than 1.0 μm, solid-liquid separation after synthesis is difficult and water resistance is poor.

  The average crystal diameter in the present invention refers to an average crystal diameter obtained by weighted averaging of crystal diameters obtained by measuring 10 or more crystal particles arbitrarily selected in an SEM photograph.

Although the molar ratio of Si / Al _{2 in} SAPO-34 of the present invention is not particularly limited, for example, 0.2 to 1.1 can be exemplified, and 0.4 to 0.8 is preferable. The reason is that if the amount is less than 0.4 or exceeds 0.8, the acid amount is already small before the saturated hydration durability treatment.

  The exchange ion of SAPO-34 of the present invention is not particularly limited, but proton is preferred for use as a catalyst, an adsorbent, or an ion exchanger. Other ions such as ammonium ion, sodium ion and calcium ion have an effect of improving durability, but may coexist with protons. However, since these coexisting ions decrease the acid amount, the exchange amount is preferably less than that of protons.

  Next, the manufacturing method of SAPO-34 of this invention is demonstrated.

  The method for producing SAPO-34 of the present invention is not particularly limited as long as SAPO-34 satisfying the above physical properties can be obtained. For example, at least phosphoric acid, an aluminum source containing no alkoxide, a silica source A particularly high-quality SAPO-34 is produced by crystallizing a composition containing tetraethylammonium ions and water and having a P / Al molar ratio of less than 1.1 under standing at a temperature exceeding 180 ° C. be able to.

  As the phosphoric acid, general industrial phosphoric acid can be used, and usually 75 to 89% phosphoric acid can be used.

  Examples of the aluminum source include pseudoboehmite, aluminum hydroxide, alumina, and aluminum isopropoxide. In particular, pseudoboehmite and aluminum hydroxide are preferable. An aluminum source containing an alkoxide such as aluminum isopropoxide is not preferable because it is expensive and an alcohol component such as isopropyl alcohol for the synthesis system affects the pressure and reaction during crystallization.

  The silica source is not particularly limited, and examples thereof include silica sol, precipitated silica, gel silica, and tetraethoxysilane. Silica sol and precipitated silica are preferred. Tetraethoxysilane is not preferred because it is expensive and the ethanol component for the synthesis system affects the reaction.

  Tetraethylammonium ions are used as the structure directing agent. This is because SAPO-34 having high water resistance can be synthesized by using tetraethylammonium ions. Examples of raw materials containing tetraethylammonium ions include tetraethylammonium hydroxide, tetraethylammonium chloride, and tetraethylammonium bromide.

  Further, water is added for the reactivity and handling of the reaction composition.

  Moreover, in order to adjust pH etc., addition of the various amines which do not have influence as structure directing agents, such as a dipropylamine, can be illustrated.

  The composition used for the reaction in the method of the present invention has a P / Al molar ratio of less than 1.1, and can be exemplified by 0.6 to less than 1.1, and more preferably 0.7 or more and 0.9 or less. . This is because SAPO-34 is difficult to be formed at 1.1 or more or less than 0.6, and amorphous alumina is easily produced as a by-product at 0.6 or more and less than 0.7. Further, SAPO-34 having a large crystal diameter is obtained when the P / Al molar ratio is less than 1.0 and the P / Al molar ratio is 0.7 or more and 0.9 or less.

The Si / Al ₂ molar ratio of the above composition used for the reaction in the method of the present invention is not particularly limited, but is particularly 0.3 to 1.0, and the structure directing agent tetraethylammonium ion / Al ratio is 0.00. 1 to 2.0 and the H ₂ O / Al ratio is preferably 10 to 100.

In the method of the present invention, the above composition is crystallized at a temperature in excess of 180 ° C.
If the crystallization temperature is too high, the pressure during crystallization increases and a special reaction kettle is required, so the crystallization temperature is preferably 220 ° C. or lower. In addition, stirring or rotation may be performed until the temperature reaches the crystallization temperature in order to make the temperature uniform, but after reaching the crystallization temperature, stirring or rotation is performed to increase the particle size. It is necessary to stop and stand still.

  The crystallization time (the time for standing after reaching the crystallization temperature) is preferably 4 to 240 hours.

  After completion of crystallization, solid-liquid separation is performed by filtration or the like, washed with pure water, and dried at an arbitrary temperature of 80 to 200 ° C. to obtain SAPO-34 containing a structure directing agent. The solid-liquid separation operation is preferably dead-end filtration such as a filter press or a belt filter.

  Since the obtained SAPO-34 contains a structure directing agent, the structure directing agent (tetraethylammonium ion) is removed before use. Examples of the removal method include heat treatment in nitrogen or air, or treatment by contact with an acid such as hydrochloric acid or sulfuric acid. In particular, heat treatment in nitrogen or air is preferable. The heat treatment temperature is preferably 500 ° C. or higher and 1200 ° C. or lower.

  The obtained SAPO-34 can be used as a catalyst, an adsorbent, or an ion exchanger as it is, or appropriately modified by ion exchange and / or metal loading.

  The SAPO-34 of the present invention is particularly useful as an ammonia adsorbent when purifying exhaust gas from an internal combustion engine such as a diesel vehicle. For example, in a composite catalyst having a part that adsorbs nitrogen oxide in exhaust gas and converts it to ammonia, and a part that adsorbs ammonia converted in the catalyst and purifies nitrogen oxide in exhaust gas to nitrogen It can be used as an ammonia adsorbent having high water resistance, heat resistance and hot water resistance.

Provided is SAPO-34 having high water resistance and large particles used as a catalyst, an adsorbent, an ion exchanger and the like.

SEM photograph of SAPO-34 obtained in Example 1 SEM photograph of SAPO-34 obtained in Example 2 SEM photograph of SAPO-34 obtained in Example 3 SEM photograph of SAPO-34 obtained in Example 3 SEM photograph of SAPO-34 obtained in Example 4 SEM photograph of SAPO-34 obtained in Example 4 SEM photograph of SAPO-34 obtained in Comparative Example 2. XRD diagrams of Examples 1 to 4

The present invention will be specifically described by the following examples, but the present invention is not limited to these examples. In addition, each measuring method in an Example and a comparative example is as follows. The sample in each measurement is SAPO-34 from which the structure directing agent has been removed by heat treatment.
(Average crystal diameter)
The sample was observed and photographed by SEM, arbitrary 10 or more crystal particles were selected from the SEM photograph, and the diameters were averaged to obtain an average crystal diameter.
(Average particle size)
Pure water is added to the sample to make a slurry with a solid content of 1%, ultrasonic dispersion is performed for 2 minutes, particle size distribution measurement (volume average) is performed by laser diffraction scattering method, and average particle size (50% particle size) is calculated. Obtained.
(Ammonia adsorption amount)
About 0.1g of precisely weighed sample was removed adsorbed component in inert gas (helium) at 500 ° C, and a mixed gas of 90% inert gas (helium) and 10% ammonia was saturated adsorbed at 25 ° C. Next, the temperature is raised to 700 ° C., and the amount of ammonia desorbed in the course of temperature rise (excluding those desorbed in the temperature range of 25 to 100 ° C.) is quantified with a TCD detector and measured separately. The amount divided by the sample amount corrected by the solid content concentration of the prepared sample was defined as acid amount = ammonia adsorption amount (unit: mmol / g).
(Saturated hydration endurance treatment)
The sample was thinned in a glass dish, and the glass dish was placed in a desiccator immersed in a saturated aqueous solution of ammonium chloride (corresponding to a relative humidity of 80%). Then, using a vacuum pump, the desiccator was degassed until the water vapor pressure alone was reached, and then the desiccator was sealed. The state was kept at 25 ° C. for 90 days.
(Hot water endurance treatment)
The sample was pressed and then pulverized and sized to 12 to 20 mesh. 1 cc of the sized sample was charged into an atmospheric pressure fixed bed flow type reaction tube, heated to 900 ° C. while flowing wet air containing 10% by volume of water vapor at 100 mL / min, and held for 1 hour.

Example 1
Pseudoboehmite (Al ₂ O ₃ = 74%), 85% phosphoric acid, silica (silica sol), tetraethylammonium hydroxide (TEAOH), and pure water 100 g of a mixed slurry having the following charging composition ratio were prepared.
Al ₂ O ₃ : 1.0P ₂ O ₅ : 0.5SiO ₂ : 2.0TEAOH: 50H ₂ O
The mixed slurry was heated in an autoclave from room temperature to 200 ° C. with stirring for about 40 minutes, and further stirred and kept standing for 120 hours for crystallization. Although the slurry after crystallization had a slow filtration rate, the solid-liquid separation of dead-end type high efficiency could be achieved with 5C filter paper. Subsequently, pure water was washed with 5C filter paper, and then dried at 110 ° C. Further, the structure directing agent TEAOH was removed by firing at 600 ° C. under air flow.

Only X-ray peaks corresponding to SAPO-34 were observed by powder X-ray diffraction. Si / Al ₂ = 0.44 and P / Al = 0.89. The average crystal diameter was 1.1 μm (see FIG. 1).

  Acid amount is 1.48 mmol / g for SAPO-34 (hereinafter referred to as “fresh product”), 1.43 mmol / g for saturated hydration durability treatment (25 ° C., relative humidity 80%, 90 days), and hot water durability treatment It was 1.31 mmol / g (900 ° C., relative humidity 10%, 1 hour).

  The obtained SAPO-34 had a large ammonia adsorption amount, that is, an acid amount during the saturation hydration durability treatment and the hot water durability treatment.

Example 2
Pseudoboehmite (Al ₂ O ₃ = 74%), 85% phosphoric acid, silica (silica sol), tetraethylammonium hydroxide (TEAOH), and pure water 100 g of a mixed slurry having the following charging composition ratio were prepared.
Al ₂ O ₃ : 1.0P ₂ O ₅ : 0.5SiO ₂ : 1.0TEAOH: 50H ₂ O
The mixed slurry was heated in an autoclave from room temperature to 200 ° C. with stirring for about 40 minutes, and further stirred and kept standing for 120 hours for crystallization. Although the slurry after crystallization had a slightly slow filtration rate, the solid-liquid separation of dead-end type high efficiency could be achieved with 5C filter paper. Subsequently, pure water was washed with 5C filter paper, and then dried at 110 ° C. Further, the structure directing agent TEAOH was removed by firing at 600 ° C. under air flow.

In powder X-ray diffraction, only the X-ray peak corresponding to SAPO-34 was observed, and in the composition analysis, Si / Al ₂ = 1.03 and P / Al = 1.29. The average crystal diameter was 1.2 μm {see FIG. 2 (same magnification as in FIG. 1)}.

  Acid amount is 0.88 mmol / g for fresh products, 0.85 mmol / g for saturated hydration endurance treatment (25 ° C., relative humidity 80%, 90 days), and for hot water endurance treatment (900 ° C., relative humidity 10%). %, 1 hour) and 0.73 mmol / g.

  The obtained SAPO-34 had a large ammonia adsorption amount, that is, an acid amount during the saturation hydration durability treatment and the hot water durability treatment.

Example 3
Pseudoboehmite (Al ₂ O ₃ = 74%), 85% phosphoric acid, silica (silica sol), tetraethylammonium hydroxide (TEAOH), and pure water 100 g of a mixed slurry having the following charging composition ratio were prepared.
Al ₂ O ₃ : 0.88P ₂ O ₅ : 0.5SiO ₂ : 2.0TEAOH: 50H ₂ O
The mixed slurry was heated in an autoclave from room temperature to 200 ° C. with stirring over about 40 minutes, and further stirred and kept standing for 84 hours for crystallization. The slurry after crystallization was able to perform solid-liquid separation of dead end type with 5C filter paper with high efficiency. The filtration rate was fast. Subsequently, pure water was washed with 5C filter paper, and then dried at 110 ° C. Further, the structure directing agent TEAOH was removed by firing at 600 ° C. under air flow.

In powder X-ray diffraction, only X-ray peaks corresponding to SAPO-34 were observed, and in composition analysis, Si / Al ₂ = 0.43 and P / Al = 0.79. The average crystal diameter was 2.5 μm {see FIG. 3 (1/10 magnification of FIG. 1) and FIG. 4 (same magnification as FIG. 1)}.

  Acid amount is 1.22 mmol / g for fresh product, 1.20 mmol / g for saturated hydration durability treatment (25 ° C., relative humidity 80%, 90 days), and for hot water durability treatment (900 ° C., relative humidity 10) %, 1 hour) and 0.95 mmol / g.

  The obtained SAPO-34 had a large ammonia adsorption amount, that is, an acid amount during the saturation hydration durability treatment and the hot water durability treatment.

Example 4
Pseudoboehmite (Al ₂ O ₃ = 74%), 85% phosphoric acid, silica (silica sol), tetraethylammonium hydroxide (TEAOH), and pure water 100 g of a mixed slurry having the following charging composition ratio were prepared.
Al ₂ O ₃ : 0.75P ₂ O ₅ : 0.5SiO ₂ : 2.0TEAOH: 50H ₂ O
The mixed slurry was heated in an autoclave from room temperature to 200 ° C. with stirring over about 40 minutes, and further stirred and held for 84 hours to crystallize while standing. The slurry after crystallization was able to perform solid-liquid separation of dead end type with 5C filter paper with high efficiency. The filtration rate was fast. Subsequently, pure water was washed with 5C filter paper, and then dried at 110 ° C. Further, the structure directing agent TEAOH was removed by firing at 600 ° C. under air flow.

In the powder X-ray diffraction, only the X-ray peak corresponding to SAPO-34 was observed, and in the composition analysis, Si / Al ₂ = 0.29 and P / Al = 0.47. The average crystal diameter was 3.8 μm {see FIG. 5 (1/10 magnification of FIG. 1) and FIG. 6 (same magnification as FIG. 1)}.

  The amount of acid was 0.82 mmol / g in a fresh product, and 0.80 mmol / g during saturated hydration durability treatment (25 ° C., relative humidity 80%, 90 days).

  The SAPO-34 of this example can be used as an ammonia adsorbent having high water resistance since the ammonia adsorption amount after the steam treatment = the acid amount is large.

Comparative Example 1
Pseudoboehmite (Al ₂ O ₃ = 74%), 85% phosphoric acid, silica (silica sol), morpholine, and pure water 100 g of a mixed slurry having the following composition ratio were prepared.
Al ₂ O ₃ : 0.80P ₂ O ₅ : 0.6SiO ₂ : 2.0 Morpholine: 50H ₂ O
The mixed slurry was heated in an autoclave from room temperature to 200 ° C. with stirring over about 40 minutes, and further stirred and kept standing for 26 hours for crystallization. The slurry after crystallization was able to perform solid-liquid separation of dead end type with 5C filter paper with high efficiency. The filtration rate was fast. Subsequently, pure water was washed with 5C filter paper, and then dried at 110 ° C. Furthermore, the structure directing agent morpholine was removed by baking at 600 ° C. under air flow.

In powder X-ray diffraction, only an X-ray peak corresponding to SAPO-34 was observed, and in compositional analysis, the average crystal diameter was 5.6 μm, which was Si / Al ₂ = 0.46 and P / Al = 0.71. It was.

  The acid amount was as large as 1.38 mmol / g in the fresh product, but was as low as 0.19 mmol / g during the saturation hydration endurance treatment (25 ° C., relative humidity 80%, 90 days).

  The obtained SAPO-34 had a large average crystal diameter, but the ammonia adsorption amount during the saturation hydration durability treatment, that is, the acid amount was extremely small.

Comparative Example 2
Pseudoboehmite (Al ₂ O ₃ = 74%), 85% phosphoric acid, silica (silica sol), tetraethylammonium hydroxide (TEAOH), and pure water 100 g of a mixed slurry having the following charging composition ratio were prepared.
Al ₂ O ₃ : 1.00P ₂ O ₅ : 0.9SiO ₂ : 2.0TEAOH: 50H ₂ O
The mixed slurry was heated from room temperature to 180 ° C. over about 35 minutes under stirring in an autoclave, and kept for 120 hours for crystallization while continuing stirring. The slurry after crystallization was subjected to dead-end solid-liquid separation of 5C filter paper, but could not be separated because SAPO-34 passed through the filter paper. Moreover, since it could not be separated by dead-end solid-liquid separation using a nitrocellulose-based filter having a pore size of 0.025 μm, solid-liquid separation was performed using a centrifugal sedimentator. Subsequently, pure water was washed by repeating the addition of pure water and centrifugal sedimentation, and then dried at 110 ° C. Further, the structure directing agent TEAOH was removed by firing at 600 ° C. under air flow.

In powder X-ray diffraction, only the X-ray peak corresponding to SAPO-34 was observed, and Si / Al ₂ = 0.58 and P / Al = 0.73 were found in the composition analysis. The average crystal diameter was as small as 0.28 μm {see FIG. 7 (same magnification as FIG. 1)}.

  The acid amount is 1.28 mmol / g for fresh products, 1.22 mmol / g for saturated hydration durability treatment (25 ° C., relative humidity 80%, 90 days), and for hot water durability treatment (900 ° C., relative At a humidity of 10% for 1 hour, it was abruptly reduced to 0.68 mmol / g.

  Table 1 below shows the solid-liquid separation method, composition analysis, average crystal diameter, average crystal diameter, and acid amount (= ammonia adsorption amount) of SAPO-34 obtained in Examples and Comparative Examples.

  SAPO-34 of Comparative Example 1 has a large average crystal diameter, but the acid amount (= ammonia adsorption amount) is already greatly reduced by hydration at low temperature (during saturated hydration durability treatment), and SAPO- of Comparative Example 2 No. 34 had a relatively small influence of hydration at room temperature, but the acid amount (= ammonia adsorption amount) was greatly reduced due to the influence of water at a high temperature (during hydrothermal durability treatment). On the other hand, SAPO-34 obtained in Examples 1 to 4 is excellent in handling properties (filterability, etc.) due to its large average crystal diameter, and also has an acid amount (= ammonia adsorption amount) due to the influence of water at room temperature and high temperature. It was a thing without the fall of.

  The SAPO-34 of the present invention can be used as a catalyst, adsorbent, ion exchanger, etc. used in an atmosphere in which water (water vapor) is present.

Claims (4)

The amount of acid measured by the ammonia temperature-programmed desorption method is 0.8 mmol / g or more at the time of saturated hydration endurance treatment after storage for 90 days in an atmosphere of 25 ° C. and 80% relative humidity , and 10% by volume of water vapor. SAPO-34 containing 0.7 mmol / g or more and an average crystal diameter of 1.0 μm or more at the time of hot water endurance treatment at 100 ° C. for 1 hour, containing flowing humid air at 100 mL / min .   The acid amount measured by the ammonia temperature-programmed desorption method is 1.2 mmol / g or more at the time of saturated hydration endurance treatment after storage treatment for 90 days in an atmosphere of 25 ° C. and 80% relative humidity. The SAPO-34 of claim 1. Crystallize a composition containing at least phosphoric acid, an alkoxide-free aluminum source, a silica source, tetraethylammonium ions and water, and having a P / Al molar ratio of less than 1.1 at a temperature exceeding 180 ° C. The method for producing SAPO-34 according to claim 1 or 2, wherein: An ammonia adsorbent comprising the SAPO-34 according to claim 1 or 2.

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