JP2011042577A - New mor type metalloaluminosilicate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new MOR type metalloaluminosilicate with a metal introduced into a skeleton, and a method for producing the same, which is easily and industrially applicable. <P>SOLUTION: Disclosed are the MOR type metalloaluminosilicate, wherein the metal is at least one selected from Ti, Ga, In, Sn and Zr, a molar ratio of the metal/Si is 0.005-0.2 and a molar ratio of Si/Al is ≥25, the metalloaluminosilicate, wherein the metal is Ti, a molar ratio of Ti/Si is 0.05-0.2 and a molar ratio of Si/Al is ≥100, and the metalloaluminosilicate, wherein the metal is Sn, a molar ratio of Sn/Si is 0.005-0.2 and a molar ratio of Si/Al is ≥100. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a novel MOR type metalloaluminosilicate. The present invention also relates to a novel method for introducing metal into the framework of MOR type zeolites.

  Today, zeolites are used in a wide range of applications in the petroleum refining, petrochemical, and environmental purification fields due to their solid acid properties and unique catalytic and adsorption properties derived from molecular size pores.

  Zeolite is a crystalline condensed aluminosilicate having a crystal skeleton composed of aluminum, silicon, and oxygen in a narrow sense, and the solid acid characteristics differ depending on the crystal structure and the aluminum content. Metalloaluminosilicates that contain other metal species such as Ga, Fe, and Ti instead of aluminum or silicon in the zeolite framework for the purpose of modifying the solid acid properties since the 1980s, or metallosilicates that do not contain aluminum, and silica only Those having a zeolite crystal structure are synthesized.

  The crystalline zeolite referred to in the present invention refers to the above-mentioned metallosilicate, metalloaluminosilicate, and crystalline silicate having a zeolite structure in addition to zeolite in a narrow sense.

  As a method for producing crystalline zeolites, a method in which an aqueous mixture mainly composed of an aluminum source, a silicon source, a metal source, and an alkali is crystallized by a hydrothermal reaction, that is, a hydrothermal synthesis method is generally used in the industry. It is. Patent Document 1 reports a MOR type titanoaluminosilicate having a Ti / Si molar ratio of 0.2 or less and a Si / Al molar ratio of 10 to 42. Patent Document 2 reports a MOR type titanoaluminosilicate having a Ti / Si molar ratio of 0.073 and a Si / Al molar ratio of 10.5. Patent Document 3 reports a titanoaluminosilicate that is considered to be MOR type having a Ti / Si molar ratio of 0.01 to 0.98 and an Si / Al molar ratio of 1 to 98. Patent Document 4 reports a MOR type ferro (alumino) silicate having an Fe / Si molar ratio of 0/0014 to 0.4 and an Si / Al molar ratio of 5.4 to infinity.

  On the other hand, there is also known a method of introducing a metal into a skeleton by treating a once synthesized zeolite with a metal salt aqueous solution treatment in a liquid phase or a metal salt vapor treatment in a gas phase. In Patent Document 5, a metal / Si molar ratio in which Al in a skeleton is replaced with chromium or tin by treatment with a chromium or tin fluoro salt aqueous solution is 0.01 to 0.98, and a Si / Al molar ratio is 50. Metalloaluminosilicates such as FAU type, MOR type, and LTL type, which are ˜98, have been reported. Patent Document 6 discloses a BEA-type gallo having a Ga / Si molar ratio of 0.0004 to 0.066 obtained by treating a BEA-type aluminosilicate or boroaluminosilicate with Al or deboron and then treating with a gallium salt aqueous solution. Aluminosilicate or galloborosilicate has been reported. Patent Document 7 discloses that a FAU type zeolite having a Si / Al molar ratio of 1.75 or more is steamed and fired, and then treated with an acid and iron salt aqueous solution so that the Fe / Si molar ratio is 0.01 to 0.30. FAU type ferroaluminosilicates having a Si / Al molar ratio of 7.5 to 50 have been reported.

  Non-Patent Document 1 discloses that a BEA type aluminosilicate having a Si / Al molar ratio of 37.5 was acid-treated and then contacted with TiCl4 vapor at 500 ° C., and the Ti / Si molar ratio was 0.018 to 0.00. A BEA type titanoaluminosilicate having a Si / Al molar ratio of 72 to 450 at 048 has been reported.

Japanese Patent Laid-Open No. 5-24820 JP-A-9-77511 Japanese Unexamined Patent Publication No. 91-501983 JP 59-116120 A Japanese Examined Patent Publication No. 7-108770 Japanese Patent Laid-Open No. 2-184517 JP-A-2-289419

Microporous and Mesoporous Materials 31 (1999) 163-173

  Hydrothermal synthesis is the most common method for producing zeolites in the industry, but since other metal species are less likely to enter the zeolite framework compared to aluminum, only a relatively small amount can be introduced into the framework and can be synthesized. There are also limited crystal structure types.

  In addition, the method of introducing metal species into the synthesized zeolite by a gas phase reaction is difficult to achieve uniform solid-gas contact, and the reaction apparatus requires special heat and corrosion resistant materials. It is hard to say that it is a method.

  The present invention provides a novel MOR type metalloaluminosilicate in which a metal is introduced into the skeleton, and a method for producing the same that is simple and industrially applicable.

  The present inventors have studied for the purpose of producing new zeolites having solid acid characteristics, adsorption characteristics, and catalytic performance that have not been obtained with conventional zeolites by inserting metal atoms into the crystal lattice. As a result, the present invention has been reached. That is, when the pH of an acidic slurry in which crystalline zeolites having lattice defects are mixed with an aqueous metal salt solution is increased using an alkali, the metal is easily introduced into the defect sites of the crystal lattice. As a result, the present invention has been completed. The present invention is described in detail below.

  In the present invention, the metal is at least one selected from Ti, Ga, In, Sn, and Zr, the metal / Si molar ratio is 0.005 to 0.2, and the Si / Al molar ratio is 25 or more. Type metalloaluminosilicate. When the metal is Ti, it is preferable that the Ti / Si molar ratio is 0.05 to 0.2 and the Si / Al molar ratio is 100 or more. When the metal is Sn, it is preferable that the Sn / Si molar ratio is 0.005 to 0.2 and the Si / Al molar ratio is 100 or more.

  In the present invention, the MOR type crystalline zeolite having lattice defects is suspended in an aqueous metal salt solution to form an acidic slurry (step a), and the pH of the acidic slurry is increased by 1 or more by adding an alkali, and the pH is A new MOR type metalloaluminosilicate characterized by comprising a step of 6 or less (step b), and a step of filtering crystals from the slurry with increased pH, washing with water and drying (step c). Manufacturing method.

  Furthermore, the metal introduced into the skeleton can be further stabilized by firing the crystals obtained in the step c at a temperature of 300 ° C. to 800 ° C.

  In addition, when sodium hydroxide or potassium hydroxide is used as the alkali, the crystals obtained in the step c may be partially obtained as alkali metal ions, so that the crystals obtained in the step c are obtained if necessary. Alkali metal ions can be removed by subjecting the crystals to normal ion exchange treatment.

  The lattice defect referred to in the present invention refers to a portion called a “nest” in the industry, in which four Si—OH groups are concentrated due to lack of aluminum or silicon atoms in a crystal skeleton composed of oxygen, silicon, and aluminum. To tell. Such lattice defects may already exist at the stage of crystallization by a hydrothermal synthesis reaction, or may be generated by a process after synthesis. As a method for generating lattice defects, a method of calcining and dealumination of a crystal, a method of dealumination of a crystal using an acid, a method of combining the firing and acid treatment, and a method of desiliconizing a crystal using an alkaline aqueous solution. And a method of dealumination.

  The raw material for preparing MOR type crystalline zeolite having lattice defects used in the production method of the present invention is MOR type aluminosilicate, metalloaluminosilicate, or silicate having lattice defects. The generation of lattice defects may be performed by any of the methods described above, but the method of dealumination using an acid is industrially simple and preferable. Depending on the zeolite, dealumination can proceed more easily by calcination before acid treatment, and in the case of MOR type zeolite, it is also preferred to calcinate before acid treatment. However, in the case of MOR type zeolite, if water vapor is present during firing, dealumination is difficult to proceed during acid treatment, and it is difficult to introduce metal into the lattice, so firing in a dry atmosphere is important.

  In the production method of the present invention, since the slurry in step a is acidic, it is obvious that dealumination of the zeolite skeleton occurs in the step and lattice defects are generated. Therefore, defect-free aluminum is used as a starting material. MOR type zeolites containing a large amount can also be used, but in that case, a part of aluminum desorbed from the skeleton is also reintroduced into the skeleton in the step b, so that the amount of the target metal introduced can be controlled. Since it becomes difficult, it is not preferable. Therefore, the Si / Al molar ratio of zeolites having lattice defects is preferably 25 or more, more preferably 50 or more, and still more preferably 100 or more.

  The pH of the slurry obtained by mixing the aqueous metal salt solution and the raw material zeolites in step a is preferably set to be equal to or lower than the aqueous metal salt solution. If the raw material zeolite is H ion type, it is not necessary to add an acid, but if it is an alkali metal ion type, the pH increases and local metal precipitation may occur. It is desirable that the pH is 1 or less, preferably 1 or less, and the metal salt in the mixed slurry is sufficiently dissolved. Further, since the metal is introduced only at the lattice defect point, it is important that the amount of the metal used is equal to or less than the lattice defect amount in the starting zeolite.

  As the alkali used in step b, sodium hydroxide, potassium hydroxide, aqueous ammonia and the like can be used. The form of the aqueous solution is suitable for handling. The concentration of the alkali to be used is not particularly limited, but if it is too high, local metal precipitation or zeolite crystal structure collapse may occur at the time of addition, so the concentration should be as low as possible, preferably 5% or less. Is desirable. Further, it is desirable that the alkali addition rate be gradually and quantitatively added. Since zeolites having many lattice defects have poor alkali resistance, it is important that the pH of the slurry added with alkali is 6 or less. Since the collapse of the zeolite crystal structure progresses as the pH exceeds 6, the final pH of the slurry is preferably in the range of 2-6, more preferably in the range of 3-6.

  Further, the metalloalumino of the present invention may be added by adding a metal salt after adding an alkali to an aqueous zeolite slurry and increasing the pH, or adding a zeolite after increasing the pH of the aqueous metal salt solution by adding an alkali. You cannot get a silicate.

  The higher the final pH, the greater the amount of metal introduced. Therefore, the amount of metal introduced can be controlled by the amount ratio of the metal salt and raw material zeolite in step a and the final pH in step b.

  The reaction temperature in step a and step b is not particularly limited, but the higher the temperature, the faster the reaction proceeds. Industrially, the range of 30 ° C to 100 ° C is preferable.

  The metal salt used in the present invention is a trivalent or tetravalent metal salt which is water-soluble and whose aqueous solution exhibits acidity. In particular, Ti, Ga, In, Sn, and Zr chlorides, sulfates, nitrates, and acetates can be preferably used.

  The present invention provides a novel MOR type metalloaluminosilicate. The present invention also provides a simple and industrial method for introducing various metals into the zeolite crystal skeleton. The novel MOR-type metalloaluminosilicate obtained by the present invention can be used as a catalyst, a catalyst base, or an adsorbent having an unprecedented performance in the fields of petroleum refining, petrochemistry, and environmental purification.

The UV diffuse reflection spectrum of the MOR type metalloaluminosilicate of the present invention in Example 1 and Example 2 and dealuminated mordenite before Ti introduction is shown.

  Hereinafter, the present invention will be described in detail with reference to examples. However, the present invention is not limited to the examples.

Example 1
600 g of hydrothermally synthesized mordenite (MOR type aluminosilicate, Si / Al molar ratio of 9.2) was ion-exchanged using 1N hydrochloric acid to exchange H ion type mordenite (Si / Al molar ratio of 15, Na / Al molar ratio of 0). .01) was prepared. 500 g of this H ion type mordenite was fired at 650 ° C. for 2 hours in a dry atmosphere. The calcined mordenite was mixed with 2,000 ml of 8N hydrochloric acid and stirred for 2 hours at 80 ° C. to remove aluminum, followed by filtration and washing with warm pure water at 80 ° C. to obtain dealuminated mordenite (Si / Al molar ratio 155). Was prepared. A titanium sulfate aqueous solution was prepared by diluting 84.1 g of an aqueous solution of titanium sulfate (IV) (manufactured by Kanto Chemical Co., Ltd., content: 24%) with 1 L of pure water, mixed with 50 g of the dealuminated mordenite absolutely dry weight, For 10 minutes. The pH at this time was 0.9. While stirring the slurry at 50 ° C., a 5% aqueous sodium hydroxide solution was continuously added at a rate of 14 ml / min to adjust the pH of the slurry to 6.0, and stirring and holding at 50 ° C. for 30 minutes. Was washed with warm pure water at 80 ° C. and dried at 120 ° C. to obtain MOR type titanoaluminosilicate of the present invention.

  Table 1 shows chemical analysis values of the obtained crystals. From the powder X-ray diffraction measurement, this maintained the high crystallinity of the MOR type, and no crystalline substance other than the MOR type was observed. Moreover, the result of UV diffuse reflection spectrum analysis of the obtained crystal is shown in FIG. In the UV spectrum of FIG. 1, the titanoaluminosilicate has a large absorption at 220 to 250 nm. This absorption is attributed to tetrahedrally coordinated titanium in the skeleton, as described in Microporous and Mesoporous Materials 31 (1999) pages 163-173. From this, it can be seen that most of the titanium is taken into the skeleton.

Example 2
A titanium sulfate aqueous solution was prepared by diluting 49.7 g of a titanium (IV) sulfate aqueous solution (manufactured by Kanto Chemical Co., Ltd., content: 24%) with 1 L of pure, and a dealuminized mordenite absolutely dry weight prepared in Example 1 was 50 g. Mix and stir at 50 ° C. for 10 minutes. The pH at this time was 1.0. While stirring the slurry at 50 ° C., a 5% aqueous sodium hydroxide solution was continuously added at a rate of 14 ml / min to adjust the pH of the slurry to 6.0, and stirring and holding at 50 ° C. for 30 minutes. Was washed with warm pure water at 80 ° C. and dried at 120 ° C. to obtain MOR type titanoaluminosilicate of the present invention.

  Table 1 shows chemical analysis values of the obtained crystals. From the powder X-ray diffraction measurement, this maintained the high crystallinity of the MOR type, and no crystalline substance other than the MOR type was observed. Moreover, the result of UV diffuse reflection spectrum analysis of the obtained crystal is shown in FIG. In the UV spectrum of FIG. 1, the titanoaluminosilicate has a large absorption at 220 to 250 nm. From this, it can be seen that most of the titanium is taken into the skeleton.

Example 3
600 g of hydrothermally synthesized mordenite (MOR type aluminosilicate, Si / Al molar ratio of 9.2) was ion-exchanged using 1N hydrochloric acid to exchange H ion type mordenite (Si / Al molar ratio of 15, Na / Al molar ratio of 0). .01) was prepared. 500 g of this H ion type mordenite was steamed for 2 hours at 650 ° C. in an atmosphere with a water vapor concentration of 50%. The calcined mordenite was mixed with 2,000 ml of 8N hydrochloric acid and stirred for 2 hours at 80 ° C. to remove aluminum, then the crystals were filtered and washed with warm pure water at 80 ° C. to obtain dealuminated mordenite (Si / Al molar ratio). 155) was prepared. A titanium sulfate aqueous solution was prepared by diluting 68.3 g of an aqueous solution of titanium sulfate (IV) (manufactured by Kanto Chemical Co., Ltd., content: 24%) with 1 L of pure, mixed with 50 g of the dealuminated mordenite absolutely dry weight, 50 ° C. For 10 minutes. The pH at this time was 0.9. While stirring the slurry at 50 ° C., a 5% aqueous sodium hydroxide solution was continuously added at a rate of 14 ml / min to adjust the pH of the slurry to 6.0, and stirring and holding at 50 ° C. for 30 minutes, followed by filtration. Then, it was washed with warm pure water at 80 ° C. and dried at 120 ° C. to obtain MOR type titanoaluminosilicate of the present invention.

  Table 1 shows chemical analysis values of the obtained crystals. From the powder X-ray diffraction measurement, this maintained the high crystallinity of the MOR type, and no crystalline substance other than the MOR type was observed.

Comparative Example 1
A titanium sulfate aqueous solution was prepared by diluting 84.1 g of an aqueous solution of titanium sulfate (IV) (manufactured by Kanto Chemical Co., Ltd., content: 24%) with 1 L of pure water. The dealuminated mordenite dry weight prepared in Example 1 was 50 g. The mixture was stirred and held at 50 ° C. for 30 minutes, and then the crystals were filtered off, washed with warm pure water at 80 ° C., and dried at 120 ° C.

  Table 1 shows chemical analysis values of the obtained crystals. It is clear that the product of the invention cannot be obtained without an increase in pH.

比較例２
硫酸チタン（ＩＶ）水溶液（関東化学（株）製、含有量２４％）８４．１ｇを純水１Ｌで希釈して硫酸チタン水溶液を調製し、実施例１で調製した脱アルミニウムモルデナイト絶乾重量５０ｇと混合して５０℃で１０分間撹拌した。この時のスラリーｐＨは０．９であった。該スラリーを５０℃で撹拌しながら、５％水酸化ナトリウム水溶液を１４ｍｌ／ｍｉｎの速度で連続的に添加してスラリーのｐＨを１０．０とし、５０℃で３０分間撹拌保持した後、結晶をろ別及び８０℃の温純水で洗浄し、１２０℃で乾燥した。

Comparative Example 2
A titanium sulfate aqueous solution was prepared by diluting 84.1 g of an aqueous solution of titanium sulfate (IV) (manufactured by Kanto Chemical Co., Ltd., content: 24%) with 1 L of pure water. The dealuminated mordenite dry weight prepared in Example 1 was 50 g. And stirred at 50 ° C. for 10 minutes. At this time, the slurry pH was 0.9. While stirring the slurry at 50 ° C., a 5% aqueous sodium hydroxide solution was continuously added at a rate of 14 ml / min to adjust the pH of the slurry to 10.0, and the mixture was stirred and held at 50 ° C. for 30 minutes. It was filtered and washed with warm pure water at 80 ° C. and dried at 120 ° C.

  From the powder X-ray diffraction measurement, the obtained crystal did not maintain the high crystallinity of the MOR type, and the XRD peak intensity was 14% with respect to dealuminated mordenite.

Claims (3)

MOR type metalloaluminosilicate in which the metal is at least one selected from Ti, Ga, In, Sn, and Zr, the metal / Si molar ratio is 0.005 to 0.2, and the Si / Al molar ratio is 100 or more. . The metalloaluminosilicate according to claim 1, wherein the metal is Ti, the Ti / Si molar ratio is 0.05 to 0.2, and the Si / Al molar ratio is 100 or more. The metalloaluminosilicate according to claim 1, wherein the metal is Sn, the Sn / Si molar ratio is 0.005 to 0.2, and the Si / Al molar ratio is 100 or more.

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