JP5017642B2 - Crystalline porous silicate having MCM-68 topology and process for producing the same - Google Patents

Description

  The present invention relates to a crystalline porous silicate having a topology of zeolite MCM-68 and containing no Al, and a process for producing the same.

Aluminosilicate MCM-68 is a relatively new zeolite synthesized by Mobil in 2000 (Patent Document 1). This zeolite has a structure in which large pores (12-membered ring pores) and medium pores (10-membered ring pores) intersect three-dimensionally. Since this type of zeolite generally has a large surface area and a large internal space, it is useful as a catalyst in petroleum refining and petrochemical processes, and is expected to be useful as a catalyst using a relatively bulky organic molecule as a substrate. MCM-68 has a Si / Al ratio of 9-12, so it has a relatively high Al content, that is, active sites, and is considered to be an acid catalyst because it is more stable. As a base material for hydrocarbon processing catalysts because of its high activity in reactions involving methane, such as alkylation of aromatic hydrocarbons, transalkylation of alkylaromatic hydrocarbons, isomerization, disproportionation, dealkylation, etc. Expected.
The manufacturing method of aluminosilicate MCM-68 by Mobil is to heat a gel obtained by mixing a template (template), colloidal silica, potassium hydroxide, aluminum hydroxide and water in an autoclave, and to fire the resulting crystals. It was a so-called hydrothermal method.
On the other hand, the present inventors have already dried the raw material mixture prepared in a gel form instead of the hydrothermal method to form a dry powder, and the resulting dry gel is brought into contact with water vapor having a saturated vapor pressure to react. A method of synthesizing aluminosilicate by the method has been developed (Patent Document 2). In addition, the present inventors have developed a synthesis method of aluminosilicate by hydrothermal synthesis using various zeolites as precursors (Patent Document 3).

Special Table 2002-535227 (WO00 / 43316) Patent No. 3322308 JP2005-82473

MCM-68 has a Si / Al ratio of 9-12, so it has a relatively high Al content, that is, active sites, and is considered to be an acid catalyst because it is more stable. As a base material for hydrocarbon processing catalysts, it is highly active in reactions involving methane, such as alkylation of aromatic hydrocarbons, transalkylation of alkylaromatic hydrocarbons, isomerization, disproportionation, and dealkylation. Expected. When the Si / Al ratio is ∞ (total silica composition), it is promising as an adsorbent, deodorant, etc., such as a volatile organic compound (VOC) that is an environmental pollutant, rather than as an acid catalyst.
In zeolite synthesis, the first strategy for obtaining a zeolite having a high Si / Al ratio (high silica) is to set a high Si / Al ratio in the synthesis gel (starting gel). However, in the synthesis of MCM-68, when the Si / Al ratio in the synthesis gel is out of the range of 9 to 12, there is a problem that not a topology of MCM-68 but a substance having another skeleton topology crystallizes. there were. For example, when the Si / Al ratio in the synthetic gel is ∞ (total silica composition), ZSM-12 (MTW topology) zeolite crystallizes.

The present inventors synthesized a titanosilicate in which Al in MCM-68 was replaced with Ti, and showed high performance for olefin epoxidation, and found that the lower the remaining amount of Al, the higher the performance. (Japanese Patent Application 2006-226279). However, in this titanosilicate manufacturing method, Al is originally removed from MCM-68 having a Si / Al ratio of 9 to 12, and therefore trace amounts of Al cannot be avoided even though the amount is small. To obtain a sample that does not contain any Al, it is necessary to crystallize the sample from a starting gel that does not contain any Al. However, it has been difficult to directly crystallize a silicate having the MCM-68 topology as described above and containing no Al at all, which has not been achieved so far.
Unnecessary Al in catalyst applications is not preferable because it causes coking (carbonaceous deposition). Samples containing no Al are essential for the synthesis of various high-purity metallosilicates (silicates containing a metal element in the skeleton) in addition to titanosilicate.
An object of the present invention is to provide a crystalline porous silicate having the topology of zeolite MCM-68 and containing no Al, and a method for producing the same. The topology of zeolite MCM-68 is uniquely determined by atomic coordinates and crystallographic parameters shown in Table 1 described later.

  The present inventors modified and used a template molecule used in the production of MCM-68, and further improved the dry gel method (Patent Document 2) developed by the present inventors to optimize other dry gel formation conditions. Thus, a crystalline porous silicate having a topology of zeolite MCM-68 and containing no Al was successfully synthesized. The crystalline porous silicate of the present invention has the MCM-68 topology even though the raw materials and the manufacturing method are completely different because the template molecule used strongly promotes the formation of the MCM-68 topology. It is considered that the affinity / hydrophobicity, size, rigidity, chemical stability, etc. of this template molecule contribute to the formation of the MCM-68 topology.

That is, the present invention has a composition formula R ₄ Si _112-n O _232-m H _{8 + 4n-2m} (where n = 0-12, m = 0-n, R is N, N, N ′, N′− Tetraalkylbicyclo [2.2.2] oct-7-ene-2,3: 5,6-dipyrrolidinium (provided that the alkyl group has 4 or less carbon atoms and may be the same or different. )) And an as-synthesized crystalline porous silicate with an X-ray diffraction pattern including the following values:
2θ (unit: degree) = 6.88 ± 0.10, 8.16 ± 0.10, 8.84 ± 0.10, 9.72 ± 0.10, 19.48 ± 0.10, 21.82 ± 0.10, 22.70 ± 0.10, 23.24 ± 0.10, but 2θ = half of the peak at 23.24 ± 0.10 The value range is 0.20 degrees or less.
The present invention, (wherein, n = 0~12, m = 0~n ) composition formula _{Si 112-n O 224-m} H 4n-2m expressed in, with X-ray diffraction pattern including the following values Crystalline porous silicate.
2θ (unit: degree) = 6.52 ± 0.10, 6.84 ± 0.10, 8.12 ± 0.10, 8.80 ± 0.10, 9.68 ± 0.10, 19.44 ± 0.10, 21.76 ± 0.10, 22.64 ± 0.10, 23.16 ± 0.10, but 2θ = 23.16 ± 0.10 The full width at half maximum of the peak is 0.20 degrees or less.

Further, the present invention provides (1) a silica source, (2) N, N, N ′, N′-tetraalkylbicyclo [2.2.2] oct-7-ene-2,3: 5,6-di Pyrrolidinium dihydroxide (however, the alkyl group has 4 or less carbon atoms and may be the same or different), (3) alkali metal hydroxide or alkaline earth metal hydroxide, And (4) a dry gelation step in which a mixture with water is dried to form a powdery dry gel, and a polymerization step in which the resulting dry gel is reacted in contact with water vapor at a saturated vapor pressure is synthesized. It is a process for producing as-synthesized crystalline porous silicate.
In addition, the present invention further includes a silylation step in which a silylating agent is added to the obtained crystalline silicate and then heated in an autoclave, and a method for producing a crystalline porous silicate. It is.

  The crystalline porous silicate containing no Al of the present invention has a sharp peak of powder X-ray diffraction (narrow half-value width) and high crystallinity, and thus has high thermal stability and hydrothermal stability, and is durable. It can be an excellent material. If the defect is filled with Si atoms, the silicate has the MCM-68 topology and the entire silica composition. Also, if the defects are partially filled with Si atoms and the remaining defects are further filled with other metal atoms, various metallosilicates having an MCM-68 skeleton can be obtained. The present invention provides the base material.

The crystalline porous silicate of the present invention does not contain Al and has the topology of zeolite MCM-68 that is uniquely determined by the atomic coordinates and crystallographic parameters shown in Table 1.
MCM-68 is an aluminosilicate with a structure in which 12-membered and 10-membered channels intersect three-dimensionally. The unit cell is a tetragonal system having a composition of Si _100.6 Al _11.4 O ₂₂₄ . The MCM-68 structure has not yet been given a three-letter code by the International Zeolite Association Structure Commission (IZA-SC), but has a skeletal topology uniquely determined by the atomic coordinates shown in Table 1. There is a straight 12-membered ring channel (diameter 0.67 nm) in the z-axis direction and two wavy 10-membered ring channels (diameter 0.50-0.55 nm) in the x-axis and y-axis directions. It also has a cavity (cage) (0.65 (1.73 nm) accessible only through a 10-membered ring (J. Phys. Chem. B, 2006, 110, 2045-2050).

Note) Space group P4 ₂ / mnm (No. 136 space group defined by International Union of Crystallography (IUCr)) Lattice constant a (= b) = 18.286 (1) A, c = 20.208 (2) A

This MCM-68 is represented by the following composition formula.
_{H n Al n Si 112-n} O 224
(In the formula, n represents 7 to 12.)
Si / Al is about 8.3-15.
The X-ray diffraction data includes the following values.
2θ = 6.56 ± 0.10, 6.88 ± 0.10, 8.16 ± 0.10, 8.80 ± 0.10, 9.70 ± 0.10, 19.50 ± 0.10 21.76 ± 0.10, 22.56 ± 0.10, 23.10 ± 0.10

The crystalline porous silicate of the present invention comprises (1) silica, (2) N, N, N ′, N′-tetraalkylbicyclo [2.2.2] oct-7-ene-2, 3: 5. 6-dipyrrolidinium dihydroxide, and (3) a dry gelation step in which a mixture of NaOH and water is dried to form a powdery dry gel, and the resulting dry gel is brought into contact with water vapor at a saturated vapor pressure And a silylation step in which a silylating agent is added to the resulting crystalline silicate and heated in an autoclave, and a calcination step in which this is baked.
Hereafter, each process is demonstrated in order.

(1) Dry gelation process:
In this step, a dry gel is prepared by mixing raw materials including a silica source.
Examples of the silica source used in the present invention include water glass, colloidal silica, fumed silica, silicon alkoxide, and quartz, and preferably fumed silica.

The mold (template) used in the present invention has the following formula:
N, N, N ′, N′-tetraalkylbicyclo [2.2.2] oct-7-ene-2,3: 5,6-dipyrrolidinium represented by the formula: is there.
The alkyl groups in the formula (ie, R ¹ and R ² ) may be the same or different and have 1 to 4 carbon atoms. R ¹ and R ² may each be the same, or all alkyl groups (ie, R ¹ and R ² ) may be the same.
As this alkyl group, for example, CH _3- , CH ₃ CH _2- , CH ₃ CH ₂ CH _2- , (CH ₃ ) ₂ CH-, CH ₃ CH ₂ CH ₂ CH _2- , (CH ₃ ) ₂ CHCH _2- , (CH ₃ CH ₂ (CH ₃ ) CH-, (CH ₃ ) ₃ C- can be mentioned,
In the dry gelation step, a hydroxide or halide (iodide, bromide, chloride, fluoride) of this compound (template), preferably a hydroxide is used.

The alkali metal hydroxide or alkaline earth metal hydroxide used in the present invention is preferably an alkali metal hydroxide, for example, LiOH, NaOH, KOH, CsOH, Mg (OH) ₂ , Ca (OH) _2. , Sr (OH) ₂ or Ba (OH) ₂ , preferably NaOH. In the case of KOH, a purity of 85% or more is used. In other cases, a purity of 95% or more is used, diluted to 5 to 50% with deionized water, or pre-diluted.
The water used is preferably high-purity water, for example, ion-exchanged water (deionized water).

Each of the above components is 10 to 50 mol, more preferably 10 to 30 mol, 1 to 30 mol, more preferably 10 to 30 mol, and 500 to 10,000 mol of water, with respect to 100 mol of silica. More preferably, it is used at a ratio of 2000 to 7000 mol.
These raw materials are appropriately mixed and stirred to obtain a uniform aqueous reaction raw material composition, which is then dried to form a dry gel. Drying is preferably performed at 40 to 100 ° C., more preferably 60 to 95 ° C., until the whole becomes a dry powder gel. The heating time is generally 0.5 to 10 hours, more preferably 1 to 5 hours.

(2) Polymerization step In this step, the powdery dry gel obtained above is reacted in contact with water vapor having a saturated vapor pressure to synthesize a crystalline silicate. In general, the target crystalline porous silicate zeolite is obtained by heating to 100 to 200 ° C., preferably 150 to 180 ° C., and reacting for about 3 hours to 10 days, preferably about 20 hours to 3 days. . In order to react powdery dry gel in contact with water vapor at saturated vapor pressure, for example, place dry gel in a suitable container in a closed reactor, and prepare water in the reactor and heat. And it can carry out by making it react in the water vapor | steam atmosphere of saturated vapor pressure.

The as-synthesized crystalline porous silicate obtained in this step is represented by the following composition formula:
R ₄ Si _112-n O _232-m H _{8 + 4n-2m}
In the formula, n represents an integer of 0 to 12, m represents an integer of 0 to n, and R represents a cation portion (R ²⁺ ) of the template obtained by removing a charge.
The X-ray diffraction data includes the following values.
2θ (unit: degree) = 6.88 ± 0.10, 8.16 ± 0.10, 8.84 ± 0.10, 9.72 ± 0.10, 19.48 ± 0.10, 21.82 ± 0.10, 22.70 ± 0.10, 23.24 ± 0.10, but 2θ = half of the peak at 23.24 ± 0.10 The value range is 0.20 degrees or less.

(3) Silylation step In this step, a silylating agent is added to the obtained crystalline porous silicate zeolite and heated in an autoclave. Since the crystalline silicate obtained above has a large number of Si defects, if it is fired as it is, the defects cannot be maintained because of the defects (see Comparative Example 1). Therefore, the silylation step is necessary to fill this defect with silica.
The silylating agent used is represented by the general formula SiZ ₄ (wherein Z may be the same or different and each represents an alkoxy group, an alkyl group or a halogen atom). Examples of the silylating agent include methyltriethoxysilane (Si (OEt) ₃ Me), methyltrimethoxysilane (Si (OMe) ₃ Me), methylchlorosilane (SiCl ₃ Me), and dichlorodimethylsilane (SiCl ₂ Me _2). ) And diethoxydimethylsilane (Si (OEt) ₂ Me ₂ ), preferably tetraethoxysilane, tetramethoxysilane or tetrachlorosilane.
In this step, the silylating agent is added to the crystalline silicate obtained above and heated in an autoclave at 120 to 200 ° C. for 0.5 to 7 days.

(4) Firing step The crystalline silicate is fired after being taken out of the autoclave. This calcination is usually performed by using a muffle furnace or a tubular furnace and circulating in an atmosphere of O ₂ : N ₂ = 0: 100 to 100: 0 at a flow rate of 0.1 to 100 ml / min for 1 to 12 hours. .

The crystalline porous silicate zeolite obtained in this step is represented by the following composition formula.
Formula _{Si 112-n O 224-m} H 4n-2m ( wherein, n 0 to 12, m represents an integer of 0 to n.)
The X-ray diffraction data includes the following values.
2θ (unit: degree) = 6.52 ± 0.10, 6.84 ± 0.10, 8.12 ± 0.10, 8.80 ± 0.10, 9.68 ± 0.10, 19.44 ± 0.10, 21.76 ± 0.10, 22.64 ± 0.10, 23.16 ± 0.10, but 2θ = 23.16 ± 0.10 The full width at half maximum of the peak is 0.20 degrees or less.
This crystalline porous silicate has the above-mentioned MCM-68 structure, and has a skeletal topology specified by the space group and atomic coordinates in Table 1 above.

  The as-synthesized crystalline porous silicate obtained in the polymerization step was synthesized as it can be seen from the fact that the crystals cannot be maintained when calcined as it is (see Comparative Example 1). The remaining crystalline porous silicate is believed to lack a large number of Si in the topology of zeolite MCM-68. In the present invention, the silylation step is performed in order to fill this defect portion with silica. However, depending on the conditions, the defect portion may not be completely filled. Therefore, the fired crystalline porous silicate obtained in the present invention is one in which all of the deficient portions are filled (n = m = 0) and one in which a portion thereof is deficient (0 <n ≦ 12, 0 <m ≦ 12) is also included. When there are the most defects (n = m = 12), the weight is reduced by 7.5% compared to the case without defects. An expected defect site is Si indicated by an arrow in FIG. However, in any case, the basic skeleton of the crystalline porous silicate of the present invention remains the MCM-68 topology.

  The crystalline porous silicate thus obtained is useful as a base material (precursor) for various metallosilicates having an MCM-68 skeleton. In addition, because of its excellent adsorption capacity, it is expected to be useful as an adsorbent and deodorant for volatile organic compounds (VOC), which are environmental pollutants.

The following examples illustrate the invention but are not intended to limit the invention.
In this example, nitrogen adsorption was measured under the following conditions.
Equipment used: Belsorp 28SA made by Nippon Bell Co., Ltd. Fully automatic adsorption measuring device Measurement temperature: -196 ℃
Air bath temperature: 40 ℃
Equilibrium adsorption time: 300 seconds Sample pretreatment conditions: 400 ° C., 2 hours X-ray diffraction was measured under the following conditions.
Equipment used: MX-Labo powder X-ray analyzer manufactured by MAC Science
X-ray source: CuKα = 1.5405A, applied voltage: 40 kV, tube current: 20 mA
Measuring range: 2θ = 2.040 ~ 52.000deg
Scan speed: 2.000 deg./min, Sampling interval: 0.040 deg.
Diverging slit: 1.00 deg, Scattering slit: 1.00 deg, Receiving slit: 0.30 mm
Using vertical goniometer and monochromator Measurement method Continuous method, normal method Grid spacing d is in angstrom units, and the peak relative intensity I / I ₀ is the intensity of the strongest peak I ₀ , and each peak is a percentage And was derived by use of a profile fitting routine (or second derivative algorithm). These intensities are not corrected for the Lorentz effect and polarization effect.

Production Example 1
In this synthesis example, the template used in the examples described later was synthesized.
First, N, N′-diethylbicyclo [2.2.2] oct-7-ene-2,3: 5,6-tetracarboxydiimide was synthesized as shown in the following formula.
Bicyclo [2.2.2] oct-7-ene-2,3: 5,6-tetracarboxylic dianhydride (manufactured by Aldrich) 15.7 g (63 mmol) was placed in a 500 ml two-necked flask, followed by ethylamine (Kanto). (Chemical) (70 wt% in water) 100 ml (1.26 mol) was added and stirred at room temperature for 2 hours. Distilled water (46 ml) was added thereto, and then refluxed, followed by stirring at 70 ° C. for 24 hours and then at 100 ° C. for 20 hours. After allowing to cool, concentrated hydrochloric acid (11 ml) was slowly added dropwise until the pH reached about 2. This was subjected to suction filtration using a Buchner funnel, and the solid obtained by washing with distilled water (500 ml) until the pH of the washing solution was almost neutral was dried at 40 ° C. The yield of the product (N, N′-diethylbicyclo [2.2.2] oct-7-ene-2,3: 5,6-tetracarboxydiimide) was 17.1 g (90% yield).

Next, N, N′-diethylbicyclo [2.2.2] oct-7-ene-2,3: 5,6-dipyrrolidine was synthesized.
N ₂ 1000 ml two-necked flask lithium aluminum hydride atmosphere put (LiAlH _4, manufactured by Wako Pure Chemical) 6.2 g (164 mmol), followed by reflux in tetrahydrofuran (THF) 300 ml, and stirring was started . The diimide 16.0 g (53 mmol) obtained above was added little by little here, and it washed in with THF (240 ml). Thereafter, the mixture was stirred for 68 hours under reflux. After allowing to cool, distilled water (6.2 g), 15 wt% NaOH (6.2 g), and distilled water (18.7 g) were added slowly in order at intervals of about 30 minutes while stirring well, in order to decompose excess LiAlH ₄ After completion, the mixture was stirred for 2 hours. Next, after suction filtration using a glass filter (G3), the solid matter on the filter was thoroughly washed with THF (120 mL), and the filtrate and the washing solution were combined and concentrated under reduced pressure. Water was completely removed from the obtained oily substance to obtain an oily product (N, N′-diethylbicyclo [2.2.2] oct-7-ene-2,3: 5,6-dipyrrolidine). The yield was 12.1 g (93% yield).

Next, N, N, N ′, N′-tetraethylbicyclo [2.2.2] oct-7-ene-2,3: 5,6-dipyrrolidinium diiodide was synthesized.
Dipyrrolidine 12.1 g (49 mmol) synthesized above was dissolved in 90 mL of ethanol (EtOH), and 17 ml (212 mmol) of ethyl iodide (EtI) was added dropwise from a dropping funnel while stirring. After completion of dropping, ethyl iodide adhering to the inner wall was added to the reaction solution together with EtOH (50 ml), and the mixture was stirred under reflux for 157 hours while keeping the system in an anhydrous state. After allowing to cool, 100 ml of acetone was added, and this was suction filtered through a glass filter (G3) to obtain a crystalline product. The crystal product was washed by heating twice with about 80 ml each of acetone, allowed to cool, then washed successively with acetone (50 mL) and benzene (40 ml) and dried in vacuo. The yield of the product (N, N, N ', N'-tetraethylbicyclo [2.2.2] oct-7-ene-2,3: 5,6-dipyrrolidinium diiodide) is 19.4 g (71% yield) Met.
The analytical value of the product is shown below.
¹ H NMR (400 MHz, D ₂ O) δ: 1.25 (12H, t, J = 7.2Hz, -CH ₃ ), 2.82 (8H, s, CH-C H ₂ -N ⁺ ), 2.89 (2H, s , -CH = CH-), 3.28 (8H, q, J = 7.5Hz, CH ₃ -C H ₂ -N ⁺ ), 3.78 (4H, d, CH-C H -CH ₂ ), 6.42 (2H, t , J = 3.8 Hz, -C H -CH =)
¹³ C NMR (100 MHz, D ₂ O) δ: 8.14, 8.99, 33.71, 40.59, 53.32, 56.24, 65.05, 134.75

Next, N, N, N ′, N′-tetraethylbicyclo [2.2.2] oct-7-ene-2,3: 5,6-dipyrrolidinium dihydroxide was synthesized.
In an Erlenmeyer flask, N, N, N ′, N′-tetraethylbicyclo [2.2.2] oct-7-ene-2,3: 5,6-dipyrrolidinium diiodide obtained in Production Example 1 (8.83 g, 15.8 mmol) was dissolved in distilled water (100 ml). To this, an ion exchange resin (Mitsubishi Chemical, DIAION, SA10A, OH form) (45 g) and distilled water (100 ml) were added and gently stirred at room temperature for 48 hours. This was filtered, concentrated under reduced pressure to 16.5 g, diluted to 28.7 g with distilled water, and N, N, N ′, N′-tetraethylbicyclo [2.2.2] oct-7-ene-2 3,5,6-dipyrrolidinium dihydroxide was obtained. As a result of titration with 0.05 M HCl, the concentration (as R ²⁺ ) was 0.516 mmol / g, and the exchange rate was 93.6%.
¹ H NMR (400 MHz, D ₂ O) δ: 1.21 (12H, t, J = 7.3Hz, -CH ₃ ), 2.77 (8H, s, CH-C H ₂ -N ⁺ ), 2.84 (2H, s , -CH = CH-), 3.24 (8H, q, J = 7.5Hz, CH ₃ -C H ₂ -N ⁺ ), 3.73 (4H, d, CH-C H -CH ₂ ), 6.37 (2H, t , J = 3.8 Hz, -C H -CH =)
¹³ C NMR (100 MHz, D ₂ O) δ: 7.93, 8.81, 33.62, 40.54, 53.17, 56.16, 64.95, 134.61

Reference example 1
In this comparative example, MCM-68 was synthesized.
In a 90 ml fluororesin (PFA) container, 6.01 g (40 mmol) of colloidal silica (DuPont, LUDOX (registered trademark) HS-40, SiO ₂ : 40 wt%) is placed, and Al (OH) ₃ 312 mg (4.0 mmol) ) Was dissolved and stirred for 10 minutes. Next, 2.48 g (15 mmol) of KOH (8 mol / l, 6.05 mmol / g) was added, stirred for 30 minutes, and finally, the template synthesized in Production Example 1, N, N, N ′, N′-tetraethyl. Bicyclo [2.2.2] oct-7-ene-2,3: 5,6-dipyrrolidinium diiodide 2.23 g (4.0 mmol) was added and stirred for 3 hours. The prepared gel was transferred to a 125 ml autoclave and left in an oven at 160 ° C. for 16 days. The resulting product was centrifuged and then dried in an oven at 80 ° C. to obtain 2.55 g of a white powder. Of these, 2.46 g was placed in an alumina petri dish, and heated to 600 ° C. at 2 ° C./min from room temperature in an air atmosphere using a muffle furnace and held at 600 ° C. for 5 hours. The mixture was allowed to cool to obtain MCM-68 crystals (white powder, 2.21 g). Si / Al = 12. The results of X-ray diffraction analysis of this crystal are shown in Table 2 below.

Example 1
N, N, N ′, N′-tetraethylbicyclo [2.2.2] oct-7-ene-2,3: 5,6-dipyrrolidinium dihydroxide aqueous solution (0.480 mmol / g) obtained in Production Example 1 ) 2.08 g (1.0 mmol) and NaOH (6.32 mmol / g) 238 mg (1.5 mmol) were weighed in a fluororesin jar and stirred for 30 minutes. To this, 601 mg (10 mmol) of fumed silica (Cabot Cab-O-Sil manufactured by Cabot) was added and stirred for 3 hours. Thereafter, stirring was continued at 80 ° C., and when the viscosity of the gel increased, stirring was performed with a fluororesin rod, and this was continued until the whole became a dry gel. As a result, a powdery dry gel was naturally obtained.
Next, 927 mg of this powdery dry gel was transferred to a fluororesin cup (21 mm inner diameter, 26 mm height), and this fluororesin cup was placed in an autoclave with an internal volume of 23 ml containing water (0.2 g). It was. The autoclave was allowed to stand at 150 ° C. for 5 days. The produced solid was transferred to a filtration device, washed with ion exchange water and dried at room temperature to obtain 670 mg of a light brown powder.

Next, 200 mg of the crystal as obtained above was placed in an autoclave having an internal volume of 23 ml, and subsequently, 1 M HNO ₃ 6.0 g and tetraethylorthosilicate (TEOS) (manufactured by Kishida Chemical) were added at 150 ° C. For 48 hours under rotation (20 rpm). Thereafter, the sample was filtered, washed with distilled water until the filtrate to be filtered became neutral, and dried in an oven at 80 ° C. to obtain 180 mg of light yellow powder crystals. 10.0 mg of the obtained crystals are put in an alumina petri dish and heated in a muffle furnace from room temperature to 120 ° C in an air atmosphere for 50 minutes, held at 120 ° C for 2 hours, and then 2 ° C / min to 500 ° C. The temperature was raised and held at 500 ° C. for 3 hours. The crystals of the calcined sample (white powder, 9.1 mg) were obtained by cooling.

  The X-ray diffraction pattern of the obtained crystal is shown in FIG. (1) shows the silicate of the present invention after dry gelation, and (2) shows MCM-68 (Reference Example 1). (1) and (2) show equivalent X-ray patterns. In addition, (1) clearly has a narrower line width than (2), and (1) shows higher crystallinity.

The X-ray diffraction results of the obtained crystals are shown in the table below.
An X-ray diffraction pattern similar to that of MCM-68 (Comparative Example 1) was obtained both after dry gelation and after silylation, but after silylation is closer to MCM-68.

  FIG. 3 shows scanning electron micrographs of the crystal after dry gelation (as-synthesized sample of the crystalline porous silicate of the present invention) and MCM-68 (Comparative Example 1). Although all the samples have a rectangular crystal form (morphology), the particle size of MCM-68 of Comparative Example 1 is as small as 0.1 μm or less, and filtration may be difficult. In contrast, the silicate of the present invention has a particle size of 0.5 to 1 μm, and has an appropriate size and shape as a catalyst material and an adsorbing material.

In addition, each sample is evacuated at 400 ° C for 2 hours to remove moisture adsorbed on the surface, and then attached to an automatic adsorption measurement device without exposing the sample to the atmosphere. Was measured at liquid nitrogen temperature (−196 ° C.) using the method. The adsorption isotherm is shown in FIG. (1) shows the crystalline porous silicate of the present invention, and (2) shows MCM-68 (Reference Example 1).
Both samples showed a sharp rise in the region where the relative pressure (horizontal axis) was 0.2 or less, and both were almost equal. This shows that the pore volume is not greatly reduced by silylation, and the pores are not blocked by silylation.
This adsorption isotherm indicates that the crystalline porous silicate (1) of the present invention has a larger amount of nitrogen adsorption than MCM-68 (2) and is an excellent adsorbent.

Comparative Example 1
Similar to Example 1, N, N, N ′, N′-tetraethylbicyclo [2.2.2] oct-7-ene-2,3: 5,6-dipyrrolidinium obtained in Production Example 3 Aqueous dihydroxide (0.480 mmol / g) 2.08 g (1.0 mmol) and NaOH (6.32 mmol / g) 238 mg (1.5 mmol) were weighed into a fluororesin jar and stirred for 30 minutes. To this, 601 mg (10 mmol) of fumed silica (Cabot Cab-O-Sil manufactured by Cabot) was added and stirred for 3 hours. Stirring was then continued at 80 ° C., and when the gel clay came up, stirring was carried out with a fluororesin stick, and this was continued until the whole became a dry gel. As a result, a powdered dry gel was obtained.
Next, this powdery dry gel was transferred to a fluororesin cup (21 mm inner diameter, 26 mm height), and this fluororesin cup was placed in an autoclave having an internal volume of 23 ml containing water (0.2 g). The autoclave was allowed to stand at 150 ° C. for 5 days. The produced solid was transferred to a filtration device, washed with ion exchange water and dried at room temperature to obtain 670 mg of a light brown powder.
Next, 5.0 mg of the crystals as obtained above was put in an alumina petri dish, heated from room temperature to 450C at 2C / min in an air atmosphere using a muffle furnace, and held at 450C for 2 hours. . The mixture was allowed to cool to obtain calcined crystals (white powder, 3.6 mg). X-ray diffraction analysis was performed, but no peak was obtained. It is thought that the crystals collapsed by heating.

It is a figure which shows the frame | skeleton topology of the crystalline porous silicate of this invention. It is a figure which shows the crystalline porous silicate X-ray diffraction pattern of this invention. (1) shows the silicate of the present invention after dry gelation, and (2) shows MCM-68 (Reference Example 1). The reason why the intensity of each peak differs depending on the sample is considered to be because the orientation differs depending on the crystal habit. It is a figure which shows the scanning electron micrograph of the crystalline porous silicate of this invention. (1) shows the silicate of the present invention after dry gelation, and (2) shows MCM-68 (Reference Example 1). The background is a copper mesh to hold the sample. It is a figure which shows the nitrogen adsorption isotherm of the crystalline porous silicate of this invention. (1) shows the silicate of the present invention after dry gelation, and (2) shows MCM-68 (Reference Example 1).

Claims (8)

Composition formula R ₄ Si _112-n O _232-m H _{8 + 4n-2m} (where n = 0 to 12, m = 0 to n, R is N, N, N ′, N′-tetraalkylbicyclo [2. 2.2] Oct-7-ene-2,3: 5,6-dipyrrolidinium (provided that the alkyl group has 4 or less carbon atoms and may be the same or different). As-synthesized crystalline porous silicate with an X-ray diffraction pattern containing the following values:
2θ (unit: degree) = 6.88 ± 0.10, 8.16 ± 0.10, 8.84 ± 0.10, 9.72 ± 0.10, 19.48 ± 0.10, 21.82 ± 0.10, 22.70 ± 0.10, 23.24 ± 0.10, but 2θ = half of the peak at 23.24 ± 0.10 The value range is 0.20 degrees or less. (1) Silica source, (2) N, N, N ′, N′-tetraalkylbicyclo [2.2.2] oct-7-ene-2,3: 5,6-dipyrrolidinium (provided that the alkyl group is The number of carbon atoms is 4 or less, and may be the same or different.) (3) Alkali metal hydroxide or alkaline earth metal hydroxide, and (4) Claims obtained by a production method comprising a dry gelation step of drying a mixture with water to form a dry powder gel and a polymerization step of reacting the obtained dry gel in contact with water vapor at a saturated vapor pressure Item 2. The crystalline porous silicate according to Item 1. Crystalline porous silicate represented by the composition formula Si _112-n O _224-m H _4n-2m (where n = 0 to 12, m = 0 to n) and having an X-ray diffraction pattern including the following values:
2θ (unit: degree) = 6.52 ± 0.10, 6.84 ± 0.10, 8.12 ± 0.10, 8.80 ± 0.10, 9.68 ± 0.10, 19.44 ± 0.10, 21.76 ± 0.10, 22.64 ± 0.10, 23.16 ± 0.10, but 2θ = 23.16 ± 0.10 The full width at half maximum of the peak is 0.20 degrees or less. (1) Silica source, (2) N, N, N ′, N′-tetraalkylbicyclo [2.2.2] oct-7-ene-2,3: 5,6-dipyrrolidinium dihydroxide ( Provided that the alkyl group has 4 or less carbon atoms and may be the same or different.), (3) alkali metal hydroxide or alkaline earth metal hydroxide, and (4) water A dry gelation step of drying the mixture into a powdery dry gel, a polymerization step of reacting the obtained dry gel in contact with water vapor at a saturated vapor pressure, and further adding a silylating agent in an autoclave. The crystalline porous silicate according to claim 3, which is obtained by a production method comprising a silylation step of heating and a baking step of baking the silylation step. The crystalline porous silicate according to claim 4, wherein the silylating agent is tetraethoxysilane, tetramethoxysilane, or tetrachlorosilane. (1) Silica source, (2) N, N, N ′, N′-tetraalkylbicyclo [2.2.2] oct-7-ene-2,3: 5,6-dipyrrolidinium dihydroxide ( Provided that the alkyl group has 4 or less carbon atoms and may be the same or different.), (3) alkali metal hydroxide or alkaline earth metal hydroxide, and (4) water As-synthesized (as-synthesized) comprising a dry gelation step of drying the mixture into a powdery dry gel and a polymerization step of reacting the obtained dry gel in contact with water vapor at a saturated vapor pressure ) Manufacturing method of crystalline porous silicate. A crystalline porous silicate further comprising a silylation step in which a silylating agent is added to the obtained crystalline porous silicate and heated in an autoclave, and a firing step in which the method is fired. The manufacturing method. The process according to claim 7, wherein the silylating agent is tetraethoxysilane, tetramethoxysilane or tetrachlorosilane.