CN109592697B

CN109592697B - IM-5 molecular sieve and synthetic method thereof

Info

Publication number: CN109592697B
Application number: CN201710914829.6A
Authority: CN
Inventors: 孙敏; 慕旭宏; 王永睿; 舒兴田
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2017-09-30
Filing date: 2017-09-30
Publication date: 2022-07-12
Anticipated expiration: 2037-09-30
Also published as: CN109592697A

Abstract

The invention discloses an IM-5 molecular sieve and a synthesis method thereof, wherein the IM-5 molecular sieve has single crystal particles with meso-positionAt S of the outer surface, at O at the center point, and at M intermediate the S and O, wherein S is SiO₂And Al₂O₃The molar ratio of the molecular sieve is maximum, and the IM-5 molecular sieve and the synthesis method thereof are applied, and the pre-synthesized H-IM-5 molecular sieve and MPP (OH)₂And/or MPP (Br)₂The crystal is contacted with the IM-5 molecular sieve in the specific environment of the alkaline aqueous solution for secondary crystallization, which is not only beneficial to improving the crystallinity of the synthesized IM-5 molecular sieve, but also beneficial to improving the IM-5 molecular sieve crystal in a microscopic sense to ensure that the surface of the IM-5 molecular sieve crystal is rich in silicon, and further can effectively reduce the acid center of the outer surface on the premise of not reducing the orifice size of the molecular sieve, thereby improving the shape selective effect of the molecular sieve.

Description

IM-5 molecular sieve and synthetic method thereof

Technical Field

The invention relates to an IM-5 molecular sieve and a synthesis method thereof.

Background

The IM-5 molecular sieve is firstly synthesized by French oil company by utilizing pyrrolidine diquaternary ammonium salt template guide (WO98/17581A1), and has a two-dimensional ten-membered ring channel structure, a limited channel with larger size is arranged in the third dimension, the channel structure of the IM-5 molecular sieve is similar to that of the ZSM-5 molecular sieve, and the molecular sieve also has a 12-membered ring cage structure.

IM-5 molecular sieves have shown excellent catalytic performance in many reactions. USP6344135 and USP6667267 report the use of catalysts containing IM-5 in hydrocracking, which can increase the conversion of the hydrocracking reaction while increasing the yield of gasoline. USP6007698 reports the use of catalysts containing IM-5 in catalytic cracking, which catalysts are effective in increasing the conversion of the reaction while increasing the yield of propylene. Meanwhile, the application of the phosphorus-containing modified IM-5 catalyst in catalytic cracking is reported to improve the yield of gasoline in the product and the selectivity of propylene (USP 6306286). CN98124173.5 reported that a catalyst containing zeolite IM-5 was effective in improving the pour point of a paraffinic hydrocarbon feed. The IM-5 molecular sieve shows good application prospect in the field of petrochemical industry.

The synthesis method of the molecular sieve IM-5 is mainly the method disclosed in WO98/17581A1 for the first 20 years. The template agent is 1, 5-bis (N-methylpyrrolidine) pentane bromine salt, the silicon source is white carbon black, and the material molar ratio of the synthesis system is 60SiO₂：1.7Al₂O₃：18Na₂O：10MPPBr₂：3000H₂And O. Crystallizing at 170 ℃ for 8-14 days to obtain the pure-phase IMF structure molecular sieve.

J Catal 2000,189:382-₂：1.5Al₂O₃：17Na₂O：6NaBr：10MPPBr₂：2400H₂O, performing static crystallization in a crystallization kettle of 60ml at 175 ℃ for 10 d. Is a strip-shaped molecular sieve with regular appearance.

J Catal,2003,215:151-170, further broadening n (SiO)₂)/n(Al₂O₃) In the range of 30 to 120, and n (NaOH)/n (SiO)₂) Narrow range, when n (NaOH)/n (SiO) is 0.5 ≦ n₂) The pure phase molecular sieve can be synthesized only when the molecular sieve is less than or equal to 0.8.

CN103101927A discloses an IM-5 molecular sieve fiber and a synthesis method thereof, which is realized by adding long carbon chain quaternary ammonium salt into a synthesis system.

CN 103101928A discloses a superfine nanometer IM-5 molecular sieve and a synthesis method thereof, which is realized by adding polyethylene glycol and long carbon chain quaternary ammonium salt into a synthesis system.

The above documents obtain different pure-phase IM-5 molecular sieves by changing the synthesis method, and the obtained molecular sieves with different crystal morphologies in the macroscopic sense are obtained, but the molecular sieve crystals in the microscopic sense are not involved, and further improvement of the molecular sieve crystals in the microscopic sense becomes another important research and development direction for researchers.

Disclosure of Invention

The invention aims to overcome the problems in the prior art and provides an IM-5 molecular sieve and a synthesis method thereof. The IM-5 molecular sieve is rich in silicon on the surface, and can effectively reduce the acid center on the outer surface, thereby improving the shape selective effect of the molecular sieve.

The inventor of the invention carries out a great deal of research on the IM-5 molecular sieve and a synthesis method thereof in order to improve the shape-selective effect of the IM-5 molecular sieve, and finds that the influence of the silicon-aluminum distribution of the IM-5 silicon-aluminum molecular sieve as a catalytic material on the catalytic performance is crucial, particularly, a molecular sieve crystal with a silicon-rich surface can effectively reduce the acid centers on the outer surface and reduce the reaction on the outer surface of the molecular sieve on the premise of not reducing the pore size of the molecular sieve, so that the reaction is mainly carried out in the pore channel of the molecular sieve, and the shape-selective effect of the molecular sieve is improved.

To this end, in one aspect of the invention, there is provided an IM-5 molecular sieve having single crystal particles of which are compared at S at the outer surface, at O at a central point, and at M intermediate said S and O, wherein SiO is in S₂And Al₂O₃The maximum molar ratio of (c).

Meanwhile, in another aspect of the invention, the synthesis method of the IM-5 molecular sieve is also provided, and comprises the following steps: s1, mixing and contacting inorganic alkali, an aluminum source, a template agent, a silicon source and water, and then carrying out hydrothermal crystallization to form IM-5 molecular sieve coarse powder; s2, preparing the IM-5 molecular sieve into H-IM-5 or NH₄-IM-5 molecular sieve; s3, adding the H-IM-5 or NH₄-IM-5 molecular sieves with MPP (OH)₂And/or MPP (Br)₂Under the condition of 160-175 ℃ to form the IM-5 molecular sieve.

In addition, in a further aspect of the invention, there is also provided an IM-5 molecular sieve synthesized by the method according to the invention.

By applying the IM-5 molecular sieve and the synthesis method thereof, the pre-synthesized H-IM-5 molecular sieve or NH is subjected to₄-IM-5 molecular sieves with MPP (OH)₂And/or MPP (Br)₂Dissolving in alkaline waterThe liquid is contacted under a specific environment for secondary crystallization, which is not only beneficial to improving the crystallinity of the synthesized IM-5 molecular sieve, but also beneficial to improving the IM-5 molecular sieve crystal in a microscopic sense to ensure that the surface of the IM-5 molecular sieve crystal is rich in silicon, thereby effectively reducing the acid center of the outer surface on the premise of not reducing the orifice size of the molecular sieve, and further improving the shape-selective effect of the molecular sieve.

Drawings

FIG. 1 is an X-ray diffraction pattern of an IM-5 molecular sieve synthesized in accordance with a comparative example;

FIG. 2 is an X-ray diffraction pattern of IM-5 molecular sieve S1 synthesized in example 1 according to the present invention;

FIG. 3 is an SEM spectrum at 500nm of IM-5 molecular sieve S1 synthesized in example 1 of the present invention.

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

In the present invention, an IM-5 molecular sieve is provided, in single crystal particles of the IM-5 molecular sieve, at S on the outer surface, at O on the center point, and at M intermediate the S and O, wherein SiO is in the S position₂And Al₂O₃The molar ratio of (a) is the largest. The IM-5 molecular sieve provided by the invention is rich in silicon on the surface, and can effectively reduce the acid center on the outer surface, thereby improving the shape-selective effect of the molecular sieve.

SiO in various positions in single crystal particles of the IM-5 molecular sieve (raw powder which is not roasted) in the invention₂And Al₂O₃The molar ratio of (A) is obtained by a TEM-EDX analysis method, and the specific measurement method comprises the following steps: (1) preparing a sample by adopting a suspension method: placing 0.01gIM-5 molecular sieve into 2ml glass bottle, dispersing with anhydrous ethanol, shaking, and taking one by dropperDripping the solution on a sample net with the diameter of 3mm, and drying to form a sample to be detected; (2) placing the sample to be tested into a sample injector of a transmission electron microscope (such as a TECNAIG2F20(200kv) transmission electron microscope of FEI company) for electron microscope observation; (3) randomly selecting 20 IM-5 molecular sieve single crystals, and analyzing SiO of each particle from edge (S at the outer surface), center (O at the central point) and edge by TEM-EDX method (wherein the beam spot is less than 1nm)₂And Al₂O₃The atomic content of (a), multipoint (e.g. 3-5 point) measurements are averaged, and the SiO in the corresponding position is calculated₂And Al₂O₃The molar ratio of (a) to (b).

The IM-5 molecular sieve of the invention preferably has SiO in S and O₂And Al₂O₃The ratio of the mole ratio of (A) to (B) is 3-10: 1, preferably 4 to 10: 1.

the IM-5 molecular sieve of the invention preferably has SiO in the O position and the M position₂And Al₂O₃The ratio of the mole ratio of (A) to (B) is 1-3: 1, preferably 1.5 to 3: 1.

the IM-5 molecular sieve of the invention preferably has SiO in the O position₂And Al₂O₃Is 30 to 100, preferably 30 to 80, more preferably 30 to 70.

Meanwhile, the invention also provides a synthesis method capable of synthesizing the IM-5 molecular sieve with silicon-rich surface, which comprises the following steps: s1, mixing inorganic alkali, an aluminum source, a template agent, a silicon source and water, contacting, and then carrying out hydrothermal crystallization to form IM-5 molecular sieve coarse powder; s2, preparing the IM-5 molecular sieve into H-IM-5 or NH₄-IM-5 molecular sieve; s3, mixing the H-IM-5 molecular sieve with MPP (OH)₂And/or MPP (Br)₂Under the condition of 160-175 ℃ to form the IM-5 molecular sieve.

According to the invention, wherein MPP (OH)₂Is 1, 5-bis (N-methylpyrrolidine) pentabasic water, MPP (Br)₂Is 1, 5-bis (N-methylpyrrolidine) pentane bromine salt.

The synthesis method of the invention is to synthesize H-IM-5 molecular sieve or NH₄-IM-5 molecular sievesAnd with MPP (OH)₂And/or MPP (Br)₂The alkaline aqueous solution is contacted under the condition of specific temperature for secondary crystallization, which is not only beneficial to improving the crystallinity of the synthesized IM-5 molecular sieve, but also beneficial to improving the IM-5 molecular sieve crystal in a microscopic sense to ensure that the surface of the IM-5 molecular sieve crystal is rich in silicon, and further can effectively reduce the acid center of the outer surface on the premise of not reducing the orifice size of the molecular sieve, thereby improving the shape selective effect of the molecular sieve.

According to the present invention, preferably, the S3 contains MPP (OH)₂And/or MPP (Br)₂The alkaline aqueous solution of (1) comprises MPP (OH)₂And/or MPP (Br)₂And optionally contain [ OH^-1]The basic substance of (1), wherein [ OH ] is contained^-1]The alkaline substance is one or more selected from sodium hydroxide, ammonia water and potassium hydroxide.

In the present invention, for the MPP (OH) containing₂And/or MPP (Br)₂The basic aqueous solution of (A) may be MPP (OH) only₂The aqueous solution of (1) may contain MPP (OH)₂And contain [ OH^-1]The alkaline substance of (1) may be an aqueous solution containing MPP (Br)₂And contain [ OH^-1]The aqueous solution of the basic substance (2) may contain MPP (OH)₂、MPP(Br)₂And contain [ OH^-1]An aqueous solution of the basic substance (2).

According to the invention, in order to further optimize the crystallinity and surface silicon content of the synthesized IM-5 molecular sieve, preferably, the S3 is used for synthesizing the H-IM-5 or NH₄-IM-5 molecular sieves with MPP (OH)₂And/or MPP (Br)₂In the step of contacting with an aqueous alkaline solution, the total [ OH ] in the system^-1]With SiO₂In a molar ratio of 0.05 to 0.4: 1, preferably 0.08 to 0.25: 1, MPP group and the total [ OH^-1]In a molar ratio of 1: 2-3, preferably 1: 2-2.4.

According to the invention, the MPP group has the following formula:

according to the invention, S3 converts the H-IM-5 or NH₄-IM-5 molecular sieves with MPP (OH)₂And/or MPP (Br)₂Due to reduction of H in the step of contacting the aqueous alkaline solution with water₂O and SiO₂The molar ratio of (A) can increase the concentration of a bulk phase, simultaneously can reduce crystallization time, increase the yield of a single kettle and improve production efficiency, and preferably, H in the system₂O and SiO₂In a molar ratio of 5-20: 1, preferably 7 to 10: 1.

according to the present invention, preferably, the S1 includes: s11, dissolving inorganic alkali, an aluminum source and a template agent in water, and mixing to prepare a mixed solution; s12, under the stirring condition, contacting the mixed solution with solid silica gel, and mixing to prepare colloid or a solid-liquid mixture; s13, carrying out hydrothermal crystallization on the colloid or the solid-liquid mixture under the crystallization reaction condition; wherein the particle size of the solid silica gel is 40-200 meshes, the bulk density is 360-500g/L, and the specific surface area is 410-520m²The pore volume is 0.88 to 1.15 mL/g; preferably, the particle size of the solid silica gel is 40-180 meshes, the bulk density is 380-500g/L, and the specific surface area is 430-480m²The pore volume is 1.01-1.10 mL/g; preferably, the water content of the solid silica gel is less than 10 wt%, preferably 6-10 wt%; the pore distribution of the solid silica gel is in the range of 2.5-22.5nm, preferably in the range of 3.5-18 nm.

The method of the invention adopts the solid silica gel with specific surface area and pore volume within a specific range as a silicon source, can effectively inhibit the production of mixed crystals (such as ZSM-12, mordenite, analcite, alpha-quartz and the like) in IM-5 molecular sieve coarse powder, and can also improve the grain size of the synthesized IM-5 molecular sieve, thereby obtaining the IM-5 molecular sieve with smaller grain size and better uniformity; in addition, the IM-5 molecular sieve synthesis method of the invention is favorable for reducing the water-silicon ratio and the mold-silicon ratio in the synthesis process by adopting the solid silica gel with the specific surface area and the pore volume within a specific range as a silicon source, and is favorable for reducing the water content in a crystallization raw material (colloid or solid-liquid mixed liquid) by setting the water-silicon ratio and the mold-silicon ratio within an optimal range, so that the concentration of a template agent is correspondingly improved, the crystallization time is further shortened, the yield of a single kettle is increased, the production efficiency is improved, and the production cost is reduced.

According to the present invention, in order to reduce the water content in the crystallization raw material (colloid or solid-liquid mixture), increase the concentration of the template agent, further shorten the crystallization time, and increase the one-pot yield, it is preferable that the solid silica gel, the aluminum source, the inorganic base, the template agent, and water in S1 are fed so that the composition of the colloid or solid-liquid mixture is SiO on a molar basis₂：Al₂O₃：M₂O：SDA：H₂O100: (0.5-10): (15-30): (6-15): (500-1400), wherein the solid silica gel is SiO₂The aluminum source is calculated as Al₂O₃Calculated as M, the inorganic base₂And O, the SDA is the template agent. More preferably, the composition of the colloid or solid-liquid mixture is SiO in molar terms₂：Al₂O₃：M₂O：SDA：H₂O＝100：(1-6)：(17.5-25)：(8-12)：(800-1200)。

According to the present invention, in the step of mixing and preparing the mixed solution, the selected water is deionized water.

According to the invention, in the above process of synthesizing the coarse powder of the IM-5 molecular sieve, the steps of preparing colloid or solid-liquid mixture, stirring, crystallization reaction, hydrothermal crystallization, cooling, washing, filtering, drying and the like are all conventional steps required to be undergone by the synthesis of the molecular sieve in the field, and related terms are well known to those skilled in the art. For example, the contacting may be by slowly adding a solid source of silicon to a mixture containing a source of aluminum. The contact process can be carried out under the condition of stirring, the contact temperature can be +/-20 ℃ at room temperature, and the contact time can be 1-3 hours.

According to the invention, the hydrothermal crystallization is generally carried out in a crystallization kettle.

According to the invention, there is no special requirement for crystallization reaction conditions in the process of synthesizing the IM-5 molecular sieve coarse powder, however, in order to improve production efficiency, the crystallization reaction conditions in S13 preferably comprise: firstly, raising the temperature of hydrothermal crystallization to 150 ℃ plus the temperature, performing hydrothermal crystallization for 1-3 days, then raising the temperature of hydrothermal crystallization to 200 ℃ plus the temperature, and continuing the hydrothermal crystallization for 2-4 days; preferably, the crystallization reaction conditions include: the hydrothermal crystallization temperature is raised to 140 ℃ for 1 to 3 days, and then raised to 180 ℃ for 170 ℃ and continued for 2 to 4 days.

According to the invention, in the process of synthesizing the IM-5 molecular sieve coarse powder, after crystallization is finished, the method further comprises the steps of cooling, washing (deionized water) and filtering the mixed solution obtained after crystallization reaction for 3-5 times, and drying at 80-100 ℃ for 12-24 hours to obtain the IM-5 molecular sieve raw powder.

According to the invention, in the process of synthesizing the IM-5 molecular sieve coarse powder, the aluminum source provides Al element necessary for forming a framework for synthesizing the IM-5 molecular sieve, so that substances capable of providing the Al element in the synthesis reaction can be used as the aluminum source, and preferably, the aluminum source is one or more of sodium metaaluminate, aluminum sulfate, aluminum chloride and aluminum nitrate.

According to the invention, in the process of synthesizing the IM-5 molecular sieve coarse powder, the template agent plays a role of structure orientation, so that the primary structural units forming the IM-5 molecular sieve, which are depolymerized from a silicon source and an aluminum source in the colloid system, grow around the template agent to form IM-5 molecular sieve crystals, and preferably, the template agent is biquaternary ammonium salt; preferably, the template agent is 1, 5-bis (N-methylpyrrolidine) pentane bromide.

According to the invention, in the process of synthesizing the IM-5 molecular sieve coarse powder, the inorganic base is a substance which is well known to those skilled in the art and is used for synthesizing the molecular sieve by hydrothermal crystallization, and preferably, the inorganic base is sodium hydroxide and/or potassium hydroxide.

According to the method of the invention, H-IM-5 or NH is synthesized in S2₄The step of preparing the molecular sieve of the formula-IM-5 may be carried out without particular limitation, and calcination and ammonium exchange may be carried out according to a conventional method. Wherein the filtering, washing, drying and calcining can be carried out according to the conventional techniques in the field, for example, the IM-5 molecular sieve coarse powder is washed to be neutral by deionized water, then dried for 5-20 hours at 80-120 ℃, calcined for 5-10 hours at 500-600 ℃, then ammonium exchanged, and then dried for 5-20 hours at 80-120 ℃, thereby obtaining NH₄IM-5, and then 500 ℃ and 600 ℃ roastingH-IM-5 is obtained after 5-10 hours.

The step of ammonium exchange may comprise: contacting the Na type IM-5 molecular sieve with an ammonium nitrate solution. In the ammonium exchange process, the solid-to-liquid ratio (g/ml) of the Na-type IM-5 molecular sieve coarse powder to the ammonium nitrate solution can be 1: (5-10). The concentration of the ammonium nitrate solution used may be 0.1-0.5 mol/L. Preferably, the ammonium exchange is carried out a plurality of times, for example 2 to 4 times, most preferably 3 times. Furthermore, each ammonium exchange may be carried out for a period of time of from 0.5 to 5 hours, preferably from 1 to 3 hours, most preferably for 2 hours.

Meanwhile, the invention also provides the IM-5 molecular sieve synthesized by the method. The single crystal particles of this IM-5 molecular sieve have a SiO in S, which is located at S of the outer surface, an O located at the center point, and a M located between S and O₂And Al₂O₃The molar ratio of (a) is maximum; preferably, the SiO in the S and O positions₂And Al₂O₃The ratio of the mole ratio of (A) to (B) is 3-10: 1, preferably 4 to 10: 1; preferably, the SiO in the O and M positions₂And Al₂O₃The ratio of the molar ratio of (A) to (B) is 1-3: 1, preferably 1.5 to 3: 1; preferably, the SiO in the O position₂And Al₂O₃The molar ratio of (A) is 30-70.

In addition, the invention also provides the application of the IM-5 molecular sieve in alkylation reaction. When the IM-5 molecular sieve synthesized by the method contains Na, the molecular sieve is further subjected to ammonium exchange and roasting treatment to form H-IM-5 before being applied to alkylation reaction, and the ammonium exchange and roasting treatment modes can be referred to in the description.

The beneficial effects of the IM-5 molecular sieve and the synthesis method thereof of the invention will be further explained by combining specific examples and comparative examples.

The relative concept and calculation of "crystallinity" in the following examples and comparative examples is illustrated as follows:

determining the structure of the IM-5 molecular sieve: the synthesized molecular sieve raw powder is determined by an XRD analysis method, and the characteristic peaks with 2 theta angles of 7.60 degrees, 7.76 degrees, 8.85 degrees, 23.09 degrees, 23.42 degrees and 25.07 degrees in the obtained XRD spectrogram are compared with the XRD spectrogram of an IM-5 molecular sieve (a comparison example) disclosed in the document < determining the pore structure of the IM-5 molecular sieve by catalytic test reaction and hydrocarbon adsorption determination >, so that whether the structure is the structure of the IM-5 molecular sieve or not is determined. XRD analysis adopts a Japanese D/MAX-IIIA type diffractometer, and the test conditions are as follows: cu target, Ka radiation, Ni filter, tube voltage 35kV, tube current 35mA, and scanning range 2 theta 4-55 deg.

Relative crystallinity values (r.c.%) were: the sum of the peak areas of five peaks (the 2 theta angles are 22.48 degrees, 23.00 degrees, 23.27 degrees, 24.09 degrees and 24.90 degrees respectively) in the 2 theta interval of 21.0-25.5 degrees of the product A0 synthesized in the comparison example is taken as a reference, and the sum is 100 percent; the ratio of the sum of peak areas of the same five peaks appearing on the XRD spectrum to the sum of peak areas of the five peaks on the XRD spectrum of a0, in percentage, of the products synthesized in the following examples and comparative examples.

The particle size and uniformity were observed by scanning electron microscopy SEM in the following examples and comparative examples.

Whether the mixed crystals exist in the following examples and comparative examples is judged by comparing diffraction peaks in XRD diffraction patterns, when the formed XRD pattern is compared with the XRD diffraction pattern in the comparative example, the IM-5 molecular sieve is considered to have no mixed crystals when no obvious mixed peak appears, and the IM-5 molecular sieve is considered to have mixed crystals when the obvious mixed peak appears.

In the following examples and comparative examples, the specifications and sources of the various reagents used are as follows:

NaOH、AlCl₃·6H₂O、Al(NO₃)₃·9H₂o is chemically pure and is produced by Beijing chemical plant;

1, 5-bis (N-methylpyrrolidine) pentanedibromide salt (MPPBR)₂) The water solution has a solid content of 58.9 percent by weight and is produced by Guangzhou Daojian refining factories;

1, 5-bis (N-methylpyrrolidine) pentabasic water (MPP (OH))₂) The solution has a solid content of 20.23 percent by weight and is produced by Guangzhou Daojian refining factories;

solid silica gel I with particle size distribution of 40-120 meshThe bulk density is 449g/L, and the water content is 6.1 wt%; pore distribution is 4nm-15nm, specific surface area is 452m²The catalyst is produced by China petrochemical Changling catalyst division company;

solid silica gel II with particle size distribution of 40-180 mesh, bulk density of 457g/L, water content of 7.5 wt%, pore distribution of 4-18 nm, and specific surface area of 480m²The catalyst is produced by China petrochemical Changling catalyst division, and the pore volume is 1.04 mL/g;

solid silica gel III with particle size distribution of 60-160 mesh, bulk density of 388g/L, water content of 6.3 wt%, pore distribution of 3.5-22.5 nm, and specific surface area of 416m²The catalyst is produced by China petrochemical Changling catalyst division, and the pore volume is 0.962 mL/g;

solid silica gel IV with particle size distribution of 60-180 mesh, bulk density of 405g/L, water content of 10 wt%, pore distribution of 4-21 nm, specific surface area of 422m²The catalyst is produced by China petrochemical Changling catalyst division, and the pore volume is 1.08 mL/g;

solid silica gel V with particle size distribution of 40-200 mesh, bulk density of 368g/L, water content of 8.13 wt%, pore distribution of 3-22 nm, and specific surface area of 404m²(ii)/g, pore volume 0.889mL/g, produced by China petrochemical Changling catalyst division;

solid silica gel VI with particle size distribution of 30-120 meshes, bulk density of 357g/L, water content of 1.8 wt%, average pore diameter of 11.5nm and specific surface area of 316m²The pore volume is 0.947mL/g, and the product is produced by Qingdao ocean chemical industry Co.Ltd;

NaAlO₂solution of Al₂O₃The content was 13.64% by weight, Na₂The O content was 20.2% by weight, and was produced by Changling catalyst division, China petrochemical Co.

Comparative example

IM-5 molecular sieves were synthesized according to the methods disclosed in the literature (Synthesis, characterization and catalytic Properties of IM-5and NU-88 molecular sieves; Synthesis, characterization, and catalytic properties of zeolites IM-5and NU-88.Journal of Catalysis 2003: 215151-170).

10.19g of 1, 5-bis (N-methylpyrrolidine) pentane bromide salt aqueous solution, 2.92g of NaOH, 1.1g of Al (NO)₃)₃·9H₂Dissolving O into proper amount of deionized waterWater, mixing evenly, adding 6.19g of white carbon black under the stirring condition to prepare milky white colloid, and the molar composition of the latex obtained by mixing is as follows: SiO 2₂：Al₂O₃：Na₂O：SDA：H₂O10: 0.167: 3.65: 1.5: 400 (wherein SDA is 1, 5-bis (N-methylpyrrolidine) pentane bromine salt). The resulting mixture was stirred at room temperature for 24 hours, and the obtained colloid was transferred to a crystallization kettle of 50ml in polytetrafluoroethylene lining, and after rotating and crystallizing at 160 ℃ for 14 days, the rotation speed was 100 rpm. Stopping the crystallization reaction, washing and filtering the product, and drying the product at 80 ℃ overnight to obtain the molecular sieve raw powder A0.

The XRD measurement result of the molecular sieve crude powder A0 (shown in figure 1) is compared with the XRD spectrum of the IM-5 molecular sieve disclosed in the document 'determination of the pore structure of the IM-5 molecular sieve by catalytic test reaction and hydrocarbon adsorption measurement', and the A0 is determined to be the IM-5 molecular sieve. The relative crystallinity of molecular sieve crude powder A0 was set to 100%.

Preparation example 1

43.87g NaAlO₂The solution, 53.576g of 30wt percent NaOH solution and 127.54g of SDA solution are dissolved in a proper amount of deionized water, evenly mixed, under the condition of stirring, 150g of solid silica gel I is slowly added to prepare milk white colloid, and the stirring is continued for 1 hour. The molar composition of the colloid was: SiO 2₂：Al₂O₃：Na₂O：SDA：H₂O＝100：2.5：17.5：8：900。

Transferring the prepared colloid into a 1L high-pressure reaction kettle with a mechanical stirrer, crystallizing at 140 ℃ for 2 days, heating to 172 ℃ for crystallization for 3 days, stopping crystallization reaction, washing and filtering the product, and drying at 80 ℃ overnight to obtain molecular sieve coarse powder A1.

XRD test is carried out on the molecular sieve crude powder A1, and the result of the test is compared with the XRD spectrum of the IM-5 molecular sieve disclosed in the literature, "the pore structure of the IM-5 molecular sieve is determined by catalytic test reaction and hydrocarbon adsorption test", and the A1 can be determined to have the structure of the IM-5 molecular sieve by comparison. Meanwhile, the IM-5 molecular sieve coarse powder A1 is measured in particle size distribution, wherein the relative crystallinity result, the mixed crystal comparison result and the particle size distribution result are shown in Table 1.

Preparation example 2

Mixing 29.25g NaAlO₂The solution, 74.843g of 30wt percent NaOH solution and 175.35g of SDA solution are dissolved in a proper amount of deionized water, the mixture is uniformly mixed, 150g of solid silica gel I is slowly added under the stirring condition to prepare milk white colloid, and the stirring is continued for 1 hour. The molar composition of the colloid was: SiO 2₂：Al₂O₃：Na₂O：SDA：H₂O＝100：1.67：20：11：1000。

Transferring the prepared colloid into a 1L high-pressure reaction kettle with mechanical stirring, crystallizing at 135 deg.C for 2 days, heating to 170 deg.C, crystallizing for 4 days, stopping crystallization reaction, washing and filtering the product, and oven drying at 80 deg.C overnight to obtain molecular sieve coarse powder A2.

XRD test is carried out on the molecular sieve crude powder A2, and the result of the test is compared with the XRD spectrum of the IM-5 molecular sieve disclosed in the literature, "the pore structure of the IM-5 molecular sieve is determined by catalytic test reaction and hydrocarbon adsorption test", and the A2 can be determined to have the structure of the IM-5 molecular sieve by comparison. Meanwhile, the IM-5 molecular sieve coarse powder A2 is measured in particle size distribution, wherein the relative crystallinity result, the mixed crystal comparison result and the particle size distribution result are shown in Table 1.

Preparation example 3

19.013gNaAlO₂The solution, 89.339g of 30wt percent NaOH solution and 165.80g of SDA solution are dissolved in a proper amount of deionized water, evenly mixed, 130g of solid silica gel I is slowly added under the stirring condition to prepare milk white colloid, and the stirring is continued for 1 hour. The molar composition of the colloid was: SiO 2₂：Al₂O₃：Na₂O：SDA：H₂O＝100：1.25：25：12：1200。

Transferring the prepared colloid into a 1L high-pressure reaction kettle with mechanical stirring, crystallizing at 140 ℃ for 2 days, heating to 180 ℃ for crystallizing for 2 days, stopping the crystallization reaction, washing and filtering the product, and drying at 80 ℃ overnight to obtain molecular sieve coarse powder A3.

XRD test is carried out on the molecular sieve coarse powder A3, and the result of the test is compared with the XRD spectrum of the IM-5 molecular sieve disclosed in the literature, "the pore structure of the IM-5 molecular sieve is determined through catalytic test reaction and hydrocarbon adsorption test", and the A3 can be determined to have the structure of the IM-5 molecular sieve through comparison. Meanwhile, the IM-5 molecular sieve coarse powder A3 is measured in particle size distribution, wherein the relative crystallinity result, the mixed crystal comparison result and the particle size distribution result are shown in Table 1.

Preparation examples 4 to 7 and comparative preparation example 1

The synthesis of the IM-5 molecular sieve coarse powder is carried out according to preparation 1, with the difference that different solid silica gels are used for the synthesis, the solid silica gel used being in the following table in comparison with the corresponding preparations and comparative examples:

serial number	Corresponding solid silica gel	Corresponding IM-5 molecular sieve coarse powder
			Preparation example 4	Solid silica gel II	A4
Preparation example 5	Solid silica gel III	A5
			Preparation example 6	Solid silica gel IV	A6
Preparation example 7	Solid silica gel V	A7
			Comparative preparation example 1	Solid silica gel VI	DA1

XRD tests are carried out on the molecular sieve coarse powder A4-A7 and DA1, and the measurement results are compared with the XRD spectrum of the IM-5 molecular sieve disclosed in the document 'determination of the pore structure of the IM-5 molecular sieve by catalytic test reaction and hydrocarbon adsorption measurement', so that the A4-A7 and the DA1 can be determined to have the IM-5 molecular sieve structure. Meanwhile, the IM-5 molecular sieve coarse powder A4-A7 and DA1 are measured in particle size distribution, wherein the relative crystallinity result, the mixed crystal ratio result and the particle size distribution result are shown in Table 1.

Preparation example 8

Synthesized according to the method of preparation example 1, except that the amount of water used was adjusted so that the molar composition of the colloid was: SiO 2₂：Al₂O₃：Na₂O：SDA：H₂O100: 2.5: 17.5: 8: 1500. molecular sieve coarse powder A8 is obtained.

XRD test is carried out on the molecular sieve coarse powder A8 and DA1, and the measurement result is compared with an XRD spectrum of the IM-5 molecular sieve disclosed in the literature that the pore structure of the IM-5 molecular sieve is determined through catalytic test reaction and hydrocarbon adsorption measurement, and the comparison can determine that A8 has the IM-5 molecular sieve structure. Meanwhile, the IM-5 molecular sieve coarse powder A8 is measured in particle size distribution, wherein the relative crystallinity result, the mixed crystal comparison result and the particle size distribution result are shown in Table 1.

Preparation example 9

Synthesized according to the method of preparation example 1, except that the amount of the template agent was adjusted so that the molar composition of the colloid was: SiO 2₂：Al₂O₃：Na₂O：SDA：H₂O100: 2.5: 17.5: 6: 900. molecular sieve coarse powder A9 is obtained.

XRD test is carried out on the molecular sieve crude powder A9, and the result of the test is compared with the XRD spectrum of the IM-5 molecular sieve disclosed in the literature, "the pore structure of the IM-5 molecular sieve is determined by catalytic test reaction and hydrocarbon adsorption test", and the A9 can be determined to have the structure of the IM-5 molecular sieve by comparison. The IM-5 molecular sieve coarse powder A9 was also measured for its particle size distribution, wherein the relative crystallinity results and the heterocrystal ratio results are shown in Table 1.

Preparation example 10

Synthesized according to the method of preparation example 1 except that crystallization was carried out at 175 ℃ for 5 days instead of 140 ℃ for 2 days under crystallization conditions, and then the temperature was raised to 172 ℃ for 3 days. Molecular sieve coarse powder A10 is obtained.

XRD test is carried out on the molecular sieve crude powder A10, and the result of the test is compared with the XRD spectrum of the IM-5 molecular sieve disclosed in the literature, "the pore structure of the IM-5 molecular sieve is determined by catalytic test reaction and hydrocarbon adsorption test", and the A10 can be determined to have the structure of the IM-5 molecular sieve by comparison. Meanwhile, the IM-5 molecular sieve coarse powder A10 is measured in particle size distribution, wherein the relative crystallinity result, the mixed crystal comparison result and the particle size distribution result are shown in Table 1.

Preparation example 11

A coarse powder of IM-5 molecular sieve was synthesized by enlarging the procedure of preparation example 1, except that:

87.75kg of NaAlO₂Solution 107.152kg of 30 wt% NaOH solution, 255.0kg of SDA solution, 300kg of solid silica gel I instead of 43.87g of NaAlO₂Solution 53.576g of 30 wt% NaOH solution, 127.54g of SDA solution and 150g of solid silica I, 2m³1L autoclave. The molar composition of the colloid was: SiO 2₂：Al₂O₃：Na₂O：SDA：H₂O100: 2.5: 17.5: 8: 900. the crystallization condition is that after crystallization is carried out for 2 days at 140 ℃, the temperature is raised to 172 ℃ for crystallization for 4 days, and molecular sieve coarse powder A11 is obtained.

XRD test is carried out on the molecular sieve coarse powder A11, and the result of the test is compared with the XRD spectrum of the IM-5 molecular sieve disclosed in the literature, "the pore structure of the IM-5 molecular sieve is determined through catalytic test reaction and hydrocarbon adsorption test", and the A11 is determined to be the IM-5 molecular sieve through comparison. The particle size distribution of molecular sieve coarse powder A11 was also measured, wherein the relative crystallinity results, the heterocrystal ratio results and the particle size distribution results are shown in Table 1.

TABLE 1

Example 1

This example illustrates the synthesis of the IM-5 molecular sieve of the invention.

(1) Using the IM-5 molecular sieve coarse powder synthesized in preparation example 1, the IM-5 molecular sieve raw powder A1 was analyzed by TEM-EDX for SiO at S on the outer surface, O at the center point, and M in the middle of S and O₂And Al₂O₃The molar ratio of (A) to (B) is determined as SiO in the O region₂And Al₂O₃Has a molar ratio of 37 to SiO in the S and O sites₂And Al₂O₃The ratio of the molar ratio of (A) to (B) (S/O) of 0.9, SiO in the O and M sites₂And Al₂O₃The ratio of the molar ratio of (B)/(C) (hereinafter referred to as O/M) was 1.0.

(2)NH₄Synthesis of IM-5and H-IM-5 molecular sieves:

and (2) performing ion exchange on the molecular sieve coarse powder in the step (1) for 3 times at 80 ℃ by using an ammonium nitrate solution with the concentration of 0.5mol/L, wherein the solid-to-liquid ratio (g/ml) is 1: 8, 2 hours each time. Washing the exchanged molecular sieve with deionized water, and drying at 90 deg.C for 10 hr to obtain NH₄Roasting at 550 deg.C for 5 hr to obtain H-IM-5 molecular sieve (Na)₂O content less than 0.1 wt%).

(3) Synthesis of IM-5 molecular sieve:

the H-IM-5 molecular sieve, a NaOH solution with the concentration of 10mol/L and MPP (OH) with the concentration of 0.76mol/L are mixed under the sealed condition₂Mixing to form a mixed solution, wherein the total [ OH ] in the mixed solution^-1]With SiO₂In a molar ratio of 0.1, MPP groups to total [ OH^-1]In a molar ratio of 1: 2.1, H₂O and SiO₂In a molar ratio of 8: 1, stirring the mixed solution at 170 ℃ for reaction, cooling after reacting for 2 days to stop the reaction, filtering, washing to neutrality by using deionized water, and drying at 90 ℃ overnight to obtain IM-5 molecular sieve product powder S1.

The XRD measurement of product powder S1 (shown in FIG. 2) was compared with the XRD spectrum of IM-5 molecular sieve disclosed in the document "determination of pore structure of IM-5 molecular sieve by catalytic test reaction and hydrocarbon adsorption measurement", and S1 was identified as IM-5 molecular sieve. The molecular sieve product powderThe relative crystallinity of S1 was 131%; according to TEM-EDX analysis, SiO at O position₂And Al₂O₃The molar ratio of (A) to (B) is 37, the S/O is 6.8 and the O/M is 1.5; the particle size of the IM-5 powder is measured by a scanning electron microscope, as shown in FIG. 3, FIG. 3 is an SEM (scanning electron microscope) spectrum of the molecular sieve product powder S1 at 500nm, and from FIG. 3, it can be seen that the molecular sieve product powder S1 has better morphology regularity and clear grain outline, and no other crystals are found; furthermore, the particle size distribution of the IM-5 powder is in the range of 150-200nm x 50-100 nm.

Example 2

(1) IM-5 molecular sieve crude powder A1 synthesized by the method in preparation example 1 was used.

(2) Synthesis of NH by the method of example 1₄-IM-5 molecular sieve coarse powder.

(3) Synthesis of IM-5 molecular sieve:

under a sealed condition, adding the NH₄IM-5 molecular sieves, NaOH solution at a concentration of 10mol/L, and MPP (OH) at a concentration of 0.76mol/L₂Mixing to form a mixed solution, wherein the total [ OH ] in the mixed solution^-1]With SiO₂In a molar ratio of 0.15, MPP groups to the total [ OH^-1]In a molar ratio of 1: 2.25, H₂O and SiO₂In a molar ratio of 10: 1, stirring the mixed solution at 175 ℃ for reaction, cooling after reacting for 1 day to stop the reaction, filtering, washing with deionized water to be neutral, and drying at 80 ℃ overnight to obtain the powder S2 of the IM-5 molecular sieve product.

The XRD measurement result of the molecular sieve raw powder S2 is compared with the XRD spectrum of the IM-5 molecular sieve disclosed in the literature, "the pore structure of the IM-5 molecular sieve is determined through catalytic test reaction and hydrocarbon adsorption measurement", and the S2 is determined to be the IM-5 molecular sieve. The relative crystallinity of the molecular sieve raw powder S2 is 127%; according to TEM-EDX analysis, SiO at O position₂And Al₂O₃The molar ratio of (A) to (B) is 36, the S/O ratio is 8.2, and the O/M ratio is 2.6; the particle size distribution of the IM-5 powder is within the range of 100-200nm x 50-100nm as determined by scanning electron microscope measurement.

Example 3

(1) IM-5 molecular sieve coarse powder was synthesized by the method of example 1.

(2) The procedure of example 1 was used to synthesize a coarse powder of H-IM-5 molecular sieve:

(3) synthesis of IM-5 molecular sieve:

the H-IM-5 molecular sieve, NaOH solution with the concentration of 10mol/L and MPP (OH) with the concentration of 0.76mol/L are added under the sealed condition₂Mixing to form a mixed solution, wherein the total [ OH ] in the mixed solution^-1]With SiO₂In a molar ratio of 0.25, MPP groups to the total [ OH^-1]In a molar ratio of 1: 2.3, H₂O and SiO₂In a molar ratio of 7: 1, stirring the mixed solution at 165 ℃ for reaction, cooling after reacting for 1 day to stop the reaction, filtering, washing with deionized water to be neutral, and drying at 100 ℃ overnight to obtain the powder S3 of the IM-5 molecular sieve product.

The XRD measurement result of the molecular sieve raw powder S3 is compared with the XRD spectrum of the IM-5 molecular sieve disclosed in the literature, "determination of the pore structure of the IM-5 molecular sieve by catalytic test reaction and hydrocarbon adsorption measurement", and the S3 is determined to be the IM-5 molecular sieve. The relative crystallinity of the molecular sieve raw powder S3 is 121%, and the TEM-EDX analysis shows that the IM-5 molecular sieve is located at S of the outer surface, at O of the central point and at SiO of M in the middle of the S and O₂And Al₂O₃The molar ratio of (A) to (B) is determined as the SiO content at O₂And Al₂O₃Has a molar ratio of 37 to SiO in the S and O sites₂And Al₂O₃The ratio of the molar ratio of (A) to (B) (S/O) is 8.3, SiO in the O and M sites₂And Al₂O₃The ratio of the molar ratio (hereinafter referred to as O/M) of (B) is 1.8, and the particle size distribution of the IM-5 powder is in the range of 100-200nm x 50-100nm as determined by scanning electron microscope measurement.

Example 4

(2) The H-IM-5 molecular sieve was synthesized by the method in example 1.

(3) Synthesis of IM-5 molecular sieve:

under the closed condition, the H-IM-5 molecular sieve and MPP (OH) with the concentration of 0.76mol/L are mixed₂Mixing to form a mixed solution, wherein the total [ OH ] in the mixed solution^-1]With SiO₂In a molar ratio of 0.18, MPP groups to the total [ OH^-1]In a molar ratio of 1: 2, H₂O and SiO₂In a molar ratio of 7: 1, stirring the mixed solution at 170 ℃ for reaction, cooling after reacting for 1 day to stop the reaction, filtering, washing with deionized water to be neutral, and drying at 90 ℃ overnight to obtain powder S4 (which is not required to be subjected to ammonium exchange treatment subsequently) of the IM-5 molecular sieve product.

The XRD measurement result of the molecular sieve product powder S4 is compared with the XRD spectrum of the IM-5 molecular sieve disclosed in the literature, "determination of the pore structure of the IM-5 molecular sieve by catalytic test reaction and hydrocarbon adsorption measurement", and S4 is determined to be the IM-5 molecular sieve. The relative crystallinity of this molecular sieve product powder S4 was 112%; according to TEM-EDX analysis, SiO at O position₂And Al₂O₃The molar ratio of (A) to (B) is 37, the S/O ratio is 4.2, and the O/M ratio is 1.5; the particle size distribution of the IM-5 powder is within the range of 100-200nm x 50-100nm as determined by scanning electron microscope measurement.

Example 5

(2) The procedure of example 1 was used to synthesize a coarse powder of H-IM-5 molecular sieve.

(3) Synthesis of IM-5 molecular sieve:

the H-IM-5 molecular sieve, a NaOH solution with the concentration of 10mol/L and MPP (Br) with the concentration of 2.07mol/L are put into a sealed condition₂Mixing to form a mixed solution, wherein the total [ OH ] in the mixed solution^-1]With SiO₂In a molar ratio of 0.24:1, MPP groups to the total [ OH ]^-1]In a molar ratio of 1: 2.2, H₂O and SiO₂In a molar ratio of 8: 1, stirring the mixed solution at 175 ℃ for reaction, cooling after reacting for 1 day to stop the reaction, filtering, and washing with deionized water until the temperature is reducedAnd (4) drying the mixture at the temperature of 90 ℃ overnight to obtain powder S5 of the IM-5 molecular sieve product.

The XRD measurement result of the molecular sieve product powder S5 is compared with the XRD spectrum of the IM-5 molecular sieve disclosed in the literature, "determination of the pore structure of the IM-5 molecular sieve by catalytic test reaction and hydrocarbon adsorption measurement", and S5 is determined to be the IM-5 molecular sieve. The relative crystallinity of this molecular sieve product powder S5 was 108%; according to TEM-EDX analysis, SiO at O position₂And Al₂O₃The molar ratio of (A) to (B) is 37, the S/O ratio is 4.1, and the O/M ratio is 1.5; the particle size distribution of the IM-5 powder is within the range of 150-250nm x 50-100nm as measured by a scanning electron microscope.

Example 6

(3) synthesis of IM-5 molecular sieves using the method of example 1: with the difference that the total [ OH ] in the mixed solution^-1]With SiO₂In a molar ratio of 0.39, MPP groups to the total [ OH^-1]In a molar ratio of 1: 3, H₂O and SiO₂In a molar ratio of 15:1, obtaining IM-5 molecular sieve product powder S6.

The XRD measurement result of the molecular sieve product powder S6 is compared with the XRD spectrum of the IM-5 molecular sieve disclosed in the literature, "determination of the pore structure of the IM-5 molecular sieve by catalytic test reaction and hydrocarbon adsorption measurement", and S6 is determined to be the IM-5 molecular sieve. The relative crystallinity of this molecular sieve product powder S6 was 98%; according to TEM-EDX analysis, SiO at O position₂And Al₂O₃The molar ratio of (A) to (B) is 35, the S/O ratio is 3.3, and the O/M ratio is 2.5; the particle size distribution of the IM-5 powder is in the range of 150-200nm x 50-100nm as measured by a scanning electron microscope.

Example 7

This example illustrates the synthesis of the IM-5 molecular sieves of the invention

Synthesis of IM-5 molecular Sieve synthesized IM-5 product S7 by the method of example 1, except that preparationIM-5 molecular sieve coarse powder A2 synthesized in example 2 was used as IM-5 molecular sieve coarse powder. TEM-EDX analysis of the IM-5 molecular sieve coarse powder A2 shows that SiO at the position of O₂And Al₂O₃Has a molar ratio of 56, an S/O ratio of 1.0, and an O/M ratio of 1.0.

The XRD measurement result of the molecular sieve product powder S7 is compared with the XRD spectrum of the IM-5 molecular sieve disclosed in the literature, "determination of the pore structure of the IM-5 molecular sieve by catalytic test reaction and hydrocarbon adsorption measurement", and S7 is determined to be the IM-5 molecular sieve. The relative crystallinity of this molecular sieve product powder S7 was 109%; according to TEM-EDX analysis, SiO at O position₂And Al₂O₃The molar ratio of (A) to (B) is 57, the S/O ratio is 7.1, and the O/M ratio is 1.7; the particle size distribution of the IM-5 powder is in the range of 150-200nm x 50-80nm as measured by a scanning electron microscope.

Example 8

IM-5 molecular Sieve synthesized IM-5 molecular Sieve product S8 was synthesized by the method in example 1, except that IM-5 molecular sieve coarse powder A3 synthesized in preparation example 3 was used as IM-5 molecular sieve coarse powder. TEM-EDX analysis of the IM-5 molecular sieve coarse powder A3 shows that SiO at the position of O₂And Al₂O₃The molar ratio of (A) to (B) was 71, S/O was 1.0, and O/M was 1.0.

The XRD measurement result of the molecular sieve product powder S8 is compared with the XRD spectrum of the IM-5 molecular sieve disclosed in the literature, "determination of the pore structure of the IM-5 molecular sieve by catalytic test reaction and hydrocarbon adsorption measurement", and S8 is determined to be the IM-5 molecular sieve. The relative crystallinity of this molecular sieve product powder S8 was 108%; according to TEM-EDX analysis, SiO at O position₂And Al₂O₃The molar ratio of (A) to (B) is 70, the S/O ratio is 6.2, and the O/M ratio is 1.5; the particle size distribution of the IM-5 powder is within the range of 150-250nm x 50-100nm as measured by a scanning electron microscope.

Example 9

Synthesis of IM-5 molecular Sieve synthesized IM-5 product S9 by the method in example 1, except that the molecular sieve synthesized in preparation example 4 was usedIM-5 molecular sieve coarse powder A4 was used as IM-5 molecular sieve coarse powder. TEM-EDX analysis of the IM-5 molecular sieve coarse powder A4 shows that SiO at the position of O₂And Al₂O₃Has a molar ratio of 37, S/O of 1.0 and O/M of 1.0.

The XRD measurement result of the molecular sieve product powder S9 is compared with the XRD spectrum of the IM-5 molecular sieve disclosed in the literature, "determination of the pore structure of the IM-5 molecular sieve by catalytic test reaction and hydrocarbon adsorption measurement", and S9 is determined to be the IM-5 molecular sieve. The relative crystallinity of this molecular sieve product powder S9 was 129%; according to TEM-EDX analysis, SiO at O position₂And Al₂O₃The molar ratio of (A) to (B) is 37, the S/O is 7.0, and the O/M is 1.5; the particle size distribution of the IM-5 powder is within the range of 150-200nm x 50-100nm as measured by a scanning electron microscope.

Example 10

IM-5 molecular sieve synthesized product S10 of IM-5 molecular sieve synthesized by the method in example 1 was used except that IM-5 molecular sieve coarse powder A8 synthesized in preparation example 8 was used as IM-5 molecular sieve coarse powder. TEM-EDX analysis of the IM-5 molecular sieve coarse powder A8 shows that SiO at the position of O₂And Al₂O₃Has a molar ratio of 35, an S/O ratio of 1.1 and an O/M ratio of 1.0.

The XRD measurement result of the molecular sieve product powder S10 is compared with the XRD spectrum of the IM-5 molecular sieve disclosed in the literature, "the pore structure of the IM-5 molecular sieve is determined through catalytic test reaction and hydrocarbon adsorption measurement", and the S11 is determined to be the IM-5 molecular sieve. The relative crystallinity of this molecular sieve product powder S11 was 110%; according to TEM-EDX analysis, SiO at O position₂And Al₂O₃The molar ratio of (A) to (B) is 36, the S/O ratio is 7.2, and the O/M ratio is 1.9; the particle size distribution of the IM-5 powder is in the range of 150-250nm x 50-80nm as measured by a scanning electron microscope.

Example 11

This comparative example is used to illustrate the synthesis of the IM-5 molecular sieve of the invention with reference to the following examples.

Synthesis of IM-5 molecular Sieve product S11 from IM-5 molecular Sieve by the method in example 1, except that IM-5 synthesized in the comparative example was usedMolecular sieve coarse powder A0 was used as IM-5 molecular sieve coarse powder. TEM-EDX analysis of the IM-5 molecular sieve coarse powder A0 shows that SiO at the position of O₂And Al₂O₃The molar ratio of (A) to (B) was 58, S/O was 1.0, and O/M was 1.0.

The XRD measurement result of the molecular sieve product powder S11 is compared with the XRD spectrum of the IM-5 molecular sieve disclosed in the literature, "determination of the pore structure of the IM-5 molecular sieve by catalytic test reaction and hydrocarbon adsorption measurement", and S11 is determined to be the IM-5 molecular sieve. The relative crystallinity of this molecular sieve product powder S11 was 113%; according to TEM-EDX analysis, SiO at O position₂And Al₂O₃The molar ratio of (A) to (B) is 58, the S/O ratio is 5.7, and the O/M ratio is 1.6; the particle size distribution of the IM-5 powder is in the range of 300-600nm multiplied by 100-150nm as measured by a scanning electron microscope.

Comparative example 1

The IM-5 molecular sieve product D1 synthesized by the IM-5 molecular sieve synthesized by the method in the example 1 is different in that in the step of synthesizing the IM-5 molecular sieve by taking the H-IM-5 molecular sieve as a raw material, the mixed solution is stirred and reacts at 120 ℃ to prepare the IM-5 molecular sieve product powder D1.

The XRD measurement result of the molecular sieve product powder D1 is compared with the XRD spectrum of the IM-5 molecular sieve disclosed in the literature, "determination of the pore structure of the IM-5 molecular sieve by catalytic test reaction and hydrocarbon adsorption measurement", and D1 is determined to be the IM-5 molecular sieve. The relative crystallinity of this molecular sieve product powder D1 was 94%; according to TEM-EDX analysis, SiO at O position₂And Al₂O₃The molar ratio of (A) to (B) is 35, the S/O ratio is 1.0, and the O/M ratio is 1.0; the particle size distribution of the IM-5 powder is within the range of 100-200nm x 50-80nm as determined by scanning electron microscope measurement.

Test example

For evaluating the catalytic performance of the IM-5 molecular sieve of the invention in a benzene/methanol alkylation reaction. The molecular sieve IM-5 powder prepared in comparative example, preparation example 1, and examples 1 to 11, and comparative example 1 was subjected to ammonium exchange treatment (ion exchange was performed 3 times with a 0.5mol/L ammonium nitrate solution at 80 ℃ C. for 2 hours each at a solid-to-liquid ratio (g/ml) of 1: 8; the molecular sieve obtained after the exchange was washed with deionized water), followed by calcination at 550 ℃ for 4 hours to obtain a molecular sieve IM-5 catalyst.

On the fixed bed reactor, 4.0gIM-5 molecular sieve catalyst is filled and N is used₂As a carrier, according to the weight ratio of benzene: the molar ratio of methanol is 1: 1 (or the molar ratio of the toluene to the methanol is 2: 1) and benzene (or toluene) and methanol are introduced at 440 ℃, 0.28MPa and the feeding mass space velocity of 2h^-1Carrier gas N₂The reaction was carried out at a molar ratio of 10 to the mixed raw materials, and the results are shown in Table 2.

Benzene conversion rate ═ [ (moles of benzene in the reaction product-moles of benzene in the product)/moles of benzene in the reaction product ] × 100%;

toluene conversion ═ 100% (mole of toluene in the reaction-mole of toluene in the product)/mole of toluene in the reaction ] ×;

p-xylene selectivity (moles of p-xylene in the product/moles of xylene in the product) x 100%.

Table 2.

Conversion at 4h of reaction

As can be seen from the data in Table 2, the IM-5 molecular sieve and the synthesis method thereof of the invention are applied by pre-synthesizing H-IM-5 molecular sieve or NH₄-IM-5 molecular sieves with MPP (OH)₂And/or MPP (Br)₂The crystal is contacted with the IM-5 molecular sieve in the specific environment of the alkaline aqueous solution for secondary crystallization, which is not only beneficial to improving the crystallinity of the synthesized IM-5 molecular sieve, but also beneficial to improving the IM-5 molecular sieve crystal in a microscopic sense to ensure that the surface of the IM-5 molecular sieve crystal is rich in silicon, and further can effectively reduce the acid center of the outer surface on the premise of not reducing the orifice size of the molecular sieve, thereby improving the shape selective effect of the molecular sieve and improving the selectivity of p-xylene.

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, several simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the present disclosure, and all fall within the scope of the invention.

Claims

1. An IM-5 molecular sieve, wherein the single crystal particles of the IM-5 molecular sieve are compared at S at the outer surface, at O at the center point, and at M intermediate the S and O, wherein SiO is in the S position₂And Al₂O₃Has the largest molar ratio of (A) to (B), SiO being in the S and O sites₂And Al₂O₃The ratio of the mole ratio of (A) to (B) is 3-10: 1.

2. the IM-5 molecular sieve of claim 1, wherein the SiO in S and O sites₂And Al₂O₃The ratio of the mole ratio of (A) to (B) is 4-10: 1.

3. the IM-5 molecular sieve of claim 1, wherein the SiO in O and M is₂And Al₂O₃The ratio of the molar ratio of (A) to (B) is 1-3: 1.

4. the IM-5 molecular sieve of claim 1, wherein the SiO in O and M is₂And Al₂O₃The ratio of the molar ratio of (A) to (B) is 1.5-3: 1.

5. the IM-5 molecular sieve of claim 1, wherein the SiO in O₂And Al₂O₃The molar ratio of (A) is 30-100.

6. The IM-5 molecular sieve of claim 1, wherein the SiO in O₂And Al₂O₃The molar ratio of (b) is 30-80.

7. The IM-5 molecular sieve of claim 1, wherein the SiO in O₂And Al₂O₃In a molar ratio of30-70。

8. A synthesis method of an IM-5 molecular sieve is characterized by comprising the following steps:

s1, mixing and contacting inorganic alkali, an aluminum source, a template agent, a silicon source and water, and then carrying out hydrothermal crystallization to form IM-5 molecular sieve coarse powder;

s2, preparing the IM-5 molecular sieve into H-IM-5 or NH₄-IM-5 molecular sieve;

s3, adding the H-IM-5 or NH₄-IM-5 molecular sieves with MPP (OH)₂And/or MPP (Br)₂The alkaline aqueous solution is subjected to contact reaction at the temperature of 160-175 ℃ to form the IM-5 molecular sieve;

the S3 converts the H-IM-5 or NH₄-IM-5 molecular sieves with MPP (OH)₂And/or MPP (Br)₂In the step of contacting with the aqueous alkaline solution, MPP groups in the system are in contact with total [ OH ]^-1]In a molar ratio of 1: 2-3;

the silicon source is solid silica gel, the particle size of the solid silica gel is 40-200 meshes, the bulk density is 500g/L, and the specific surface area is 410-520m²The pore volume is 0.88-1.15 mL/g.

9. The method of claim 8, wherein said S3 includes MPP (OH)₂And/or MPP (Br)₂The alkaline aqueous solution of (1) comprises MPP (OH)₂And/or MPP (Br)₂And contain [ OH^-1]The basic substance of (1), wherein [ OH ] is contained^-1]The alkaline substance is one or more selected from sodium hydroxide, ammonia water and potassium hydroxide.

10. The method of claim 8, wherein said S3 combines said H-IM-5 or NH₄-IM-5 molecular sieves with MPP (OH)₂And/or MPP (Br)₂In the step of contacting with an aqueous alkaline solution, the total [ OH ] in the system^-1]With SiO₂In a molar ratio of 0.05-0.4: 1, MPP group and the total [ OH^-1]In a molar ratio of 1: 2-3.

11. The method of claim 8Wherein said S3 converts said H-IM-5 or NH₄-IM-5 molecular sieves with MPP (OH)₂And/or MPP (Br)₂In the step of contacting with an aqueous alkaline solution, the total [ OH ] in the system^-1]With SiO₂In a molar ratio of 0.08-0.25: 1.

12. the method of claim 8, wherein said S3 combines said H-IM-5 or NH₄-IM-5 molecular sieves with MPP (OH)₂And/or MPP (Br)₂In the step of contacting the aqueous alkaline solution, MPP groups in the system are in contact with the total [ OH ]^-1]In a molar ratio of 1: 2-2.4.

13. The process of claim 8, wherein said S3 further comprises contacting said H-IM-5 molecular sieve with a compound containing MPP (OH)₂And/or MPP (Br)₂In the step of contacting with an aqueous alkaline solution, H in the system₂O and SiO₂In a molar ratio of 5-20: 1.

14. the process of claim 8, wherein said S3 further comprises contacting said H-IM-5 molecular sieve with a compound containing MPP (OH)₂And/or MPP (Br)₂In the step of contacting with an aqueous alkaline solution, H in the system₂O and SiO₂In a molar ratio of 7-10: 1.

15. the method according to claim 8, wherein the S1 includes:

s11, dissolving inorganic alkali, an aluminum source and a template agent in water, and mixing to prepare a mixed solution;

s12, under the stirring condition, contacting the mixed solution with solid silica gel, and mixing to prepare colloid or a solid-liquid mixture;

s13, carrying out hydrothermal crystallization on the colloid or the solid-liquid mixture under the crystallization reaction condition.

16. The method as claimed in claim 8, wherein the solid silica gel has a particle size of 40-180 mesh, a bulk density of 380-500g/L, a specific surface area of 430-480m²The pore volume is 1.01-1.10 mL/g.

17. The method of claim 8, wherein the solid silica gel has a water content of less than 10 wt%; the pores of the solid silica gel are distributed in the range of 2.5-22.5 nm.

18. The method of claim 8, wherein the solid silica gel has a water content of 6-10 wt%; the pore distribution of the solid silica gel is in the range of 3.5-18.0 nm.

19. The method of claim 15, wherein the feeding of solid silica gel, the aluminum source, the inorganic base, the templating agent, and water in S1 results in the composition of the colloid or solid-liquid mixture being SiO on a molar basis₂：Al₂O₃：M₂O：SDA：H₂O100: (0.5-10): (15-30): (6-15): (500-1400), wherein the solid silica gel is SiO₂The aluminum source is calculated as Al₂O₃Calculated as M, the inorganic base₂And O, the SDA is the template.

20. The method of claim 15, wherein the composition of the colloid or solid-liquid mixture is, on a molar basis: SiO 2₂：Al₂O₃：M₂O：SDA：H₂O＝100：(1-6)：(17.5-25)：(8-12)：(800-1200)。

21. The method of claim 15, wherein the crystallization reaction conditions in S13 comprise: the hydrothermal crystallization temperature is raised to 150 ℃ below zero and 120 ℃ for 1 to 3 days, and then the hydrothermal crystallization temperature is raised to 200 ℃ below zero and 160 ℃ for 2 to 4 days.

22. The method of claim 15, wherein the crystallization reaction conditions in S13 comprise: the hydrothermal crystallization temperature is raised to 140 ℃ for 1 to 3 days, and then raised to 180 ℃ for 170 ℃ and continued for 2 to 4 days.

23. The method according to any one of claims 8 to 22, wherein in S1,

the aluminum source is one or more of sodium metaaluminate, aluminum sulfate, aluminum chloride and aluminum nitrate;

the template agent is biquaternary ammonium salt;

the inorganic base is NaOH and/or KOH.

24. The method of claim 23, wherein, in S1, the template is MPP (Br)₂。

25. An IM-5 molecular sieve synthesized by the method of any one of claims 8 to 24.