CN113578377A - Synthetic method of pore-enlarging Ti-MWW molecular sieve - Google Patents

Synthetic method of pore-enlarging Ti-MWW molecular sieve Download PDF

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CN113578377A
CN113578377A CN202110788438.0A CN202110788438A CN113578377A CN 113578377 A CN113578377 A CN 113578377A CN 202110788438 A CN202110788438 A CN 202110788438A CN 113578377 A CN113578377 A CN 113578377A
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titanium
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陈晓晖
楚吉东
胡晖
黄清明
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Fuzhou University
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Abstract

The invention discloses a synthetic method of a pore-enlarging Ti-MWW molecular sieve. The method comprises the following steps: (1) mixing a boron-containing MWW molecular sieve carrier ERB-1-P synthesized by a steam transmission method, an inorganic titanium source, a fluorine source and acid, and then condensing and refluxing for a plurality of hours; (2) filtering, washing and drying the solid-liquid mixture obtained in the step (1) to obtain carrier powder; (3) and (3) placing the powder in the step (2) in an alkaline solution containing a surfactant for constant-temperature treatment for several hours, and then washing, drying and roasting to obtain the pore-expanding Ti-MWW molecular sieve. Compared with the traditional steam transmission method, the catalyst synthesized by the method has larger specific surface area and higher activity in olefin epoxidation, the synthesis period is shortened by 58%, the acid consumption is reduced by 70%, the titanium feeding process is more efficient and controllable, and the method is favorable for industrial production.

Description

Synthetic method of pore-enlarging Ti-MWW molecular sieve
Technical Field
The invention relates to a preparation method of a pore-enlarging Ti-MWW molecular sieve, belonging to the field of inorganic synthesis.
Background
In 2001, Wu et al (Journal of Physical Chemistry B, 2001, 105(150): 2897-. This synthesis method requires the addition of large amounts of templating agent and boric acid, but the boric acid is poorly utilized and generates large amounts of wastewater. In 2002, Wu et al (Chemical Communications,2002,10: 1026-. The synthesis method needs to firstly synthesize the boron-containing ERB-1 carrier by a hydrothermal method, then remove boron and carry out secondary hydrothermal titanium feeding, and has the advantages of long synthesis period, complex operation and large template agent consumption.
In 2004, Wu et al (Journal of Physical Chemistry B,2004,108(50):19126-19131) used a surfactant based on the secondary hydrothermal synthesis method to obtain a Del-Ti-MWW molecular sieve with a high specific surface area. In 2005, Wu et al (Catalysis Today,2005,99(1-2):233-240) successfully synthesized Ti-MWW molecular sieves for the first time by a dry gel method, which basically comprises the steps of uniformly mixing a silicon source, a titanium source and boric acid to obtain dry gel, and then crystallizing under the action of piperidine or hexamethyleneimine steam. The method can realize crystallization only by needing little water and template agent, but the method also has the problems that the titanium is low in efficiency, the grain diameter of the synthesized molecular sieve crystal is generally larger than that of the synthesized molecular sieve crystal by a classical hydrothermal method, the activity in hexene epoxidation reaction is lower, and the like.
In 2018, Ge and the like (Applied Catalysis A-General,2018,564:218-225) successfully synthesized an ERB-1 carrier with boron removed by a dry glue method for hydrothermal reaction, and then coated with titanium to obtain a Ti-MWW molecular sieve with catalytic activity equivalent to that of the conventional hydrothermal method. However, the method also has the problems of too long pickling and boron removal time and too high temperature, and the problem of too much template agent and solvent in the traditional secondary hydrothermal synthesis is still not solved by titanium in the secondary hydrothermal process.
CN106517234A discloses a dynamic hydrothermal method for synthesizing a peel-off MWW molecular sieve, and a Ti-MWW molecular sieve with a peel-off structure is obtained through one-step hydrothermal synthesis, so that the operation steps are greatly reduced, but the whole synthesis period is prolonged due to the fact that the crystallization time is still too long, and the reduction of the industrial production cost is not facilitated.
At present, a method for synthesizing the Ti-MWW molecular sieve, which can simultaneously solve the problems of long synthesis period, low efficiency of titanium addition, poor catalytic performance and large use amount of an organic template agent, does not exist. The method can simultaneously solve the problems of long synthesis period of the classical hydrothermal method, low catalytic activity of the traditional dry gel method and low efficiency of the titanium-loading mode in the secondary synthesis method. The method is convenient for synthesizing the reaming Ti-MWW molecular sieve with high catalytic performance more efficiently, and is beneficial to large-scale industrial production.
Disclosure of Invention
The invention aims to provide a method for efficiently and quickly synthesizing a chambered Ti-MWW molecular sieve. The method is characterized in that ERB-1-P containing boron is synthesized by a steam transmission method and used as a carrier, and the carrier is mixed with an inorganic titanium source, a fluorine source and acid at a certain temperature to obtain a Ti-MWW precursor; and then fully mixing the Ti-MWW precursor with an alkali solution containing a surfactant at a certain temperature, and then washing, drying and roasting to obtain the pore-expanding Ti-MWW molecular sieve.
The invention relates to a method for synthesizing a chambering Ti-MWW molecular sieve, which comprises the following steps:
(1) preparation of the carrier: preparing boron-containing MWW carrier (Applied Catalysis A-General,2018(564):218-225) by dry gel method, mixing silicon source, boron source, seed crystal and water according to molar ratio SiO2/B2O3＝3～20、SiO2/H20.01 to 0.1 mass% of SiO2Fully mixing and aging the seed crystal 5-100 for 0.5-4 hours, and evaporating to dryness to obtain dry powder; putting the dry powder into a pressure container with organic amine template and water for static crystallization at constant temperature, and then washing and drying the crystallized solid to obtain the boron-containing MWW molecular sieve carrier ERB-1-P;
(2) preparation of Ti-MWW molecular sieve precursor: adding the molecular sieve carrier ERB-1-P obtained in the step (1) into a normal-pressure container, adding an inorganic titanium source, a fluorine source and strong acid, mixing, and refluxing titanium at a certain temperature for a certain time, wherein the molar ratio of silicon to fluorine is 1-40, and the molar ratio of silicon to titanium is 2-80; and then washing, drying and grinding the solid after the titanium is coated to obtain the Ti-MWW molecular sieve precursor.
(3) Preparing a pore-enlarging Ti-MWW molecular sieve: adding the Ti-MWW molecular sieve precursor obtained in the step (2) into a polytetrafluoroethylene container, then adding an alkaline solution containing a surfactant, uniformly mixing, carrying out reflux treatment at 30-120 ℃ for a period of time, and then washing, drying and roasting the obtained solid to obtain the expanded Ti-MWW molecular sieve; wherein the mass fraction of solute components in the alkaline solution is 5-25%, and the mass ratio of the carrier, the surfactant and the alkaline solution is 1 (1-10) to (10-25).
In the step (1), the silicon source is one or more of tetraethyl orthosilicate, white carbon black, silica gel and silica sol; the seed crystal is one or more of ITQ-1, boron-containing MWW (B-MWW) and boron-removed MWW (DB-MWW); the organic amine template agent is one or more of piperidine, hexamethyleneimine and ethylenediamine.
In the step (2), the inorganic titanium source is one or more of titanium tetrachloride, titanium sulfate, ammonium fluotitanate and fluotitanic acid; the fluorine source is one or more of hydrofluoric acid, ammonium fluoride and ammonium bifluoride; the strong acid is one or more of hydrochloric acid, sulfuric acid and nitric acid; the acid concentration is 0.5-4 mol/L; the reflux temperature is 50-120 ℃, and the reflux time is 0.5-10 hours.
The surfactant in the step (3) is one or more of sodium dodecyl sulfate, hexadecyl ammonium bromide and hexadecyl ammonium hydroxide; the alkaline solution is one or more of sodium hydroxide solution, ammonia water, tetraethyl ammonium hydroxide solution, tetrapropyl ammonium hydroxide solution and tetrabutyl ammonium hydroxide solution; the reflux treatment time is 1-20 hours, and the reflux treatment temperature is 45-95 ℃; the roasting temperature is 450-650 ℃, and the roasting time is 3-15 hours.
The reaming Ti-MWW molecular sieve prepared by the synthesis method provided by the invention can be applied to selective oxidation reaction of allyl alcohol, n-pentene, n-hexene, n-heptene and cyclohexene. Wherein, the yield in the n-hexylene epoxidation reaction is fourteen times of that of the traditional dry gel method.
Compared with the prior art, the invention has the following remarkable advantages:
1. compared with the traditional dry glue method, the acid washing is carried out while the acid washing is carried out, the artificial control of the titanium adding amount is realized by controlling the acid washing time, the problems that the titanium adding efficiency is low and the process is uncontrollable in the dry glue method are solved, the acid washing time of the traditional dry glue method is 20 hours, the acid washing time of the acid washing method is only 0.5-10 hours, and the acid washing time after the crystallization of the Ti-MWW molecular sieve is greatly shortened.
2. In the traditional synthesis process, a titanium source, a silicon source, an organic amine template and a solvent are fully mixed and then crystallized, anatase and six-coordination non-framework titanium are generated due to instability of the titanium source in the process, so that the content of four-coordination framework titanium is very low, and further negative influence is generated on the catalytic activity of the Ti-MWW molecular sieve. The invention uses the boron-containing MWW layered precursor as a carrier, while ERB-1-P has a unique layered structure, which is beneficial to the titanium entering into the MWW framework in the titanium feeding process, and the strong acid environment can effectively inhibit the titanium source from decomposing into anatase or changing into six-coordination non-framework titanium.
3. Compared with a secondary hydrothermal synthesis method, the method has the advantages that the used organic amine template agent and water are greatly reduced, long-time acid pickling for boron removal is not needed, the used acid amount is 0.5-4 mol/L, and the secondary hydrothermal method at least needs 6mol/L for acid pickling; the secondary hydrothermal synthesis method needs to perform long-time acid washing and boron removal on the MWW molecular sieve containing the boron three-dimensional structure, and then an organic amine template, a titanium source and a solvent are added to convert the three-dimensional MWW molecular sieve into the two-dimensional layered MWW molecular sieve, and a large amount of template is needed in the process. The method directly uses the layered carrier to carry out titanium feeding at normal pressure and lower temperature, saves the step of converting the three-dimensional MWW molecular sieve into the two-dimensional MWW molecular sieve, avoids high temperature and high pressure required by hydrothermal synthesis, and is a green, efficient and safe synthesis method.
Drawings
FIG. 1 is the XRD spectrum of the pore-enlarged Ti-MWW molecular sieve of the product obtained in example 1.
Detailed Description
The invention is further illustrated by the following specific examples. Each example lists only technical data in each step.
Example 1:
the first step is as follows: preparation of the support
Taking 20g of white carbon black (Shanghai Bing Kogyo Co., Ltd.), 1.03g of boric acid (national drug group chemical reagent Co., Ltd.), 1g of seed crystal and 500g of water, fully mixing, aging for 1 hour, evaporating to dryness at 80 ℃, grinding to obtain dry powder, and placing the dry powder in a small container; then 16g of piperidine (national drug group chemical Co., Ltd.) and 10g of water were put into a high-pressure reaction vessel with a polytetrafluoroethylene liner and a small vessel was placed therein. Then statically crystallizing at 160 ℃ for 24 hours, taking out, washing to be neutral by using deionized water, then drying overnight, and grinding to obtain the carrier ERB-1-P. Wherein the molar ratio of silicon to boron in the preparation process of the dry powder is 20, the molar ratio of silicon to water is 0.012, the seed crystal is DB-MWW, and the mass of the seed crystal is 10 percent of that of the silicon source; the molar ratio of silicon to templating agent during crystallization was 1.774.
The second step is that: preparation of Ti-MWW molecular sieve precursor
10g of the ERB-1-P carrier obtained in the first step, 2g of titanium sulfate (national chemical group chemical Co., Ltd.), 0.43g of ammonium bifluoride (national chemical group chemical Co., Ltd.), and 200ml of 2mol/L nitric acid were mixed and added to a normal pressure vessel, and refluxed at 80 ℃ for 1 hour. And after the titanium is coated, washing the obtained solid to be neutral by using deionized water, drying overnight, and grinding to obtain the Ti-MWW molecular sieve precursor. Wherein the mixture has a silicon-titanium molar ratio of 20 and a silicon-fluorine molar ratio of 20.
The third step: preparation of reaming Ti-MWW molecular sieve
Adding 8g of the Ti-MWW molecular sieve precursor obtained in the second step into a polytetrafluoroethylene container, then adding 22.4g of cetyl ammonium bromide (CTAB) and 120g of ammonia water with the mass fraction of 10%, uniformly mixing, refluxing at 60 ℃ for 12 hours, washing the obtained solid to be neutral by using deionized water, drying overnight, grinding, and then roasting at 570 ℃ for 8 hours to obtain the pore-expanding Ti-MWW molecular sieve. Wherein the mass ratio of the molecular sieve precursor to CTAB to ammonia water is 1:2.8: 15.
Example 2: the same as example 1, except that the silicon source in the first step is tetraethyl orthosilicate, the seed crystal is ITQ-1, the aging time is 0.5 hour, the evaporation temperature is 70 ℃, the organic template agent is hexamethyleneimine, the static crystallization time is 36 hours, and the crystallization temperature is 140 ℃; wherein the molar ratio of the silicon source, the boron source and the water in the preparation process of the dry powder is 1:0.2:60, and the mass of the seed crystal is 1% of that of the silicon source. In the second step, the inorganic titanium source is titanium tetrachloride, the fluorine source is hydrofluoric acid, the strong acid is hydrochloric acid of 1mol/L, the reflux temperature is 65 ℃, the reflux time is 0.5 hour, and the molar ratio of Si, the inorganic titanium source and the fluorine source in the carrier is 1:0.1: 0.1. In the third step, the surfactant is cetyl ammonium hydroxide, the alkali solution is 5% tetrabutyl ammonium hydroxide solution, the reflux temperature is 80 ℃, the reflux time is 16 hours, the roasting temperature is 550 ℃, and the roasting time is 10 hours. Wherein the mass ratio of the molecular sieve precursor to the surfactant to the alkali solution is 1:5.6: 13.5.
Example 3: the same as example 1, except that the silicon source in the first step is silica gel, the seed crystal is B-MWW, the aging time is 2 hours, the evaporation temperature is 90 ℃, the organic template agent is ethylenediamine, the static crystallization time is 48 hours, and the crystallization temperature is 180 ℃; wherein the molar ratio of the silicon source to the boron source to the water in the preparation process of the dry powder is 1:0.1: 80, the mass of the seed crystal is 5 percent of the mass of the silicon source. In the second step, the inorganic titanium source is ammonium fluotitanate, the fluorine source is ammonium fluoride, the strong acid is 2mol/L sulfuric acid, the reflux temperature is 75 ℃, the reflux time is 2 hours, and the molar ratio of Si, the inorganic titanium source and the fluorine source in the carrier is 1:0.2: 0.1. In the third step, the surfactant is sodium dodecyl sulfate, the alkali solution is 10% tetraethyl ammonium hydroxide solution, the reflux temperature is 95 ℃, the reflux time is 10 hours, the roasting temperature is 550 ℃, and the roasting time is 6 hours. Wherein the mass ratio of the molecular sieve precursor to the surfactant to the alkali solution is 1:1.4: 15.
Example 4: the same as example 1, except that the first step silicon source is silica sol, the seed crystal is B-MWW, the aging time is 4 hours, the evaporation temperature is 100 ℃, the organic template agent is ethylenediamine, the static crystallization time is 12 hours, and the crystallization temperature is 200 ℃; wherein the molar ratio of the silicon source, the boron source and the water in the preparation process of the dry powder is 1:0.2:40, and the mass of the seed crystal is 20% of that of the silicon source. In the second step, the inorganic titanium source is fluotitanic acid, the fluorine source is ammonium fluoride, the strong acid is 1mol/L nitric acid, the reflux temperature is 100 ℃, the reflux time is 4 hours, and the molar ratio of Si, the inorganic titanium source and the fluorine source in the carrier is 1:0.02: 0.05. In the third step, the surfactant is sodium dodecyl sulfate, the alkali solution is 15% tetrapropyl ammonium hydroxide solution, the reflux temperature is 90 ℃, the reflux time is 6 hours, the roasting temperature is 600 ℃, and the roasting time is 10 hours. Wherein the mass ratio of the molecular sieve precursor to the surfactant to the alkali solution is 1:1: 20.
Example 5: the same as example 1, except that the silicon source in the first step is silica gel, the seed crystal is ITQ-1, the aging time is 2 hours, the evaporation temperature is 110 ℃, the organic template agent is hexamethyleneimine, the static crystallization time is 56 hours, and the crystallization temperature is 170 ℃; wherein the molar ratio of the silicon source, the boron source and the water in the preparation process of the dry powder is 1:0.1:30, and the mass of the seed crystal is 1 percent of that of the silicon source. In the second step, the inorganic titanium source is titanium tetrachloride, the fluorine source is hydrofluoric acid, the strong acid is sulfuric acid with the concentration of 1mol/L, the reflux temperature is 110 ℃, the reflux time is 3 hours, and the molar ratio of Si, the inorganic titanium source and the fluorine source in the carrier is 1:0.04: 0.1. In the third step, the surfactant is sodium dodecyl sulfate, the alkali solution is 10% tetraethyl ammonium hydroxide solution, the reflux temperature is 80 ℃, the reflux time is 1 hour, the roasting temperature is 580 ℃, and the roasting time is 6 hours. Wherein the mass ratio of the molecular sieve precursor to the surfactant to the alkali solution is 1:10: 25.
Example 6: the same as example 1, except that the silicon source in the first step is tetraethyl orthosilicate, the seed crystal is B-MWW, the aging time is 3 hours, the evaporation temperature is 70 ℃, the organic template agent is hexamethyleneimine, the static crystallization time is 48 hours, and the crystallization temperature is 180 ℃; wherein the molar ratio of the silicon source, the boron source and the water in the preparation process of the dry powder is 1:0.05:80, and the mass of the seed crystal is 5% of that of the silicon source. In the second step, the inorganic titanium source is ammonium fluotitanate, the fluorine source is ammonium fluoride, the strong acid is 4mol/L nitric acid, the reflux temperature is 90 ℃, the reflux time is 2 hours, and the molar ratio of Si, the inorganic titanium source and the fluorine source in the carrier is 1:0.1: 0.02. In the third step, the surfactant is cetyl ammonium hydroxide, the alkali solution is 5% tetrapropyl ammonium hydroxide solution, the reflux temperature is 40 ℃, the reflux time is 4 hours, the roasting temperature is 550 ℃, and the roasting time is 10 hours. Wherein the mass ratio of the molecular sieve precursor to the surfactant to the alkali solution is 1:5.6: 15.
Comparative example 1
This comparison illustrates the synthesis of Ti-MWW molecular sieves according to the conventional dry gel process proposed by Wu et al (Catalysis Today,2005,99(1-2): 233-. Preparing the Ti-MWW molecular sieve according to a one-time dry glue method, firstly putting 50mL of water into a normal-pressure container, then sequentially adding white carbon black, boric acid, seed crystal and titanium sulfate, fully mixing, aging for 1 hour, and then evaporating to dryness at 80 ℃ to obtain the dry glue. And then the dry glue is placed in piperidine steam for static crystallization for 168 hours at 170 ℃ to obtain the Ti-MWW molecular sieve. Wherein the seed crystal is DB-MWW, the mol ratio of Si/Ti is 30, Si/B is 2, SiO2:PI:H2O is 1:0.69:2.5, and the seed amount is 10% of the mass of the silicon source.
Comparative example 2
This comparison shows a Del-Ti-MWW molecular sieve synthesized based on the secondary hydrothermal synthesis method as proposed by Wu et al (Journal of Physical Chemistry B,2004,108(50): 19126-19131). Firstly, treating a mixed solution of a highly deboronated MWW molecular sieve synthesized by a hydrothermal method, tetrabutyl titanate (TBOT) and piperidine at 170 ℃ for 7 days, and then using 2mol/L nitric acid for pickling for 18 hours to remove non-framework titanium to obtain a Ti-MWW layered precursor; and fully mixing the obtained Ti-MWW precursor, hexadecylammonium bromide, tetrapropylammonium hydroxide and water, treating at 80 ℃ for 16 hours, and finally washing, drying and roasting to obtain the Del-Ti-MWW molecular sieve. Wherein SiO is2:TiO2:PI:H2O ═ 1:0.02:1.4: 19; the mass ratio of the Ti-MWW precursor to the hexadecyl ammonium bromide to the tetrapropyl ammonium hydroxide to the water is 1:5.6 (5.0-6.5): 12.
The catalysts obtained in examples 1 to 6 and the catalysts of comparative examples 1 to 2 were subjected to activity tests, and epoxidation of 1-hexene was carried out as a probe reaction under the conditions: 10mmol of 1-hexene, 10mmol of hydrogen peroxide, 10ml of solvent, 0.5g of internal standard cyclohexanone and 0.05g of catalyst, the reaction temperature is 60 ℃, and the reaction time is 2 h.
The chromatographic analysis method comprises the following steps: the chromatographic type is as follows: agilent 6890, chromatography column; the capillary column model: agilent 19091J-413. Gas conditions: hydrogen flow rate: 40 mL/min; air flow rate: 450 mL/L; the split ratio was 3. The temperature is programmed to have an initial temperature of 50 ℃, a retention time of 2min, a temperature rise rate of 5 ℃/min, a termination temperature of 250 ℃ and a retention time of 1 min.
The catalytic results of the catalysts of examples 1-6 and comparative examples 1-2 in the n-hexene epoxidation reaction are shown in table 1.
The XRD patterns of examples 2-6 are consistent with those of FIG. 1, and are typical pore-expanded Ti-MWW molecular sieves.
In fig. 1, the molecular sieve has typical MWW structure characteristic peaks 2 θ of 7.22 °,7.90 °,9.54 °,14.42 °,16.14 °,22.64 °,23.72 °,26.14 °; the 2 θ of 0.81 ° corresponds to a diffraction peak of the (001) plane of MWW in a layered structure. X-ray powder diffractometer (XRD, PANALYTICAL Axios Petro diffractometer) uses Cu-K alpha as a radiation source, and the test conditions are as follows: the voltage is 45kV, the current is 40mA, the scanning range is 0-45 degrees, and the scanning speed is 0.1313 degrees/s.
The above examples describe only the most representative embodiments of the present invention in detail, but the present invention is not limited to the details of the above embodiments. On the basis of the technical idea of the invention, a person skilled in the art can combine the various embodiments of the invention at will. Therefore, several modifications based on the technical idea of the present invention should be covered within the protective scope of the present invention. In order to avoid unnecessary repetition, the technical features described in the embodiments above may be combined in any suitable manner, and the invention will not be further described in any possible combination.
TABLE 1
Figure RE-GDA0003267061570000121
。

Claims (10)

1. A synthetic method of a reaming Ti-MWW molecular sieve is characterized by comprising the following steps:
(1) preparation of the carrier: preparing a boron-containing MWW carrier ERB-1-P by using a dry glue method, fully mixing a silicon source, a boron source, a seed crystal and water, aging for 0.5-4 hours, evaporating to dryness at 50-110 ℃ to obtain dry powder, putting the dry powder into a pressure container of an organic amine template and water, statically crystallizing for 0.5-3 days at a constant temperature, wherein the crystallization temperature is 140-210 ℃, and washing and drying a solid obtained after crystallization to obtain the boron-containing MWW molecular sieve carrier ERB-1-P; wherein the molar ratio of the silicon source to the boron source in the preparation process of the dry powder is as follows: 3-20; the molar ratio of the silicon source to the water is 0.01-0.1; the mass ratio of the silicon source to the seed crystal is 5-100;
(2) preparation of Ti-MWW molecular sieve precursor: placing the carrier obtained in the step (1) in a normal-pressure container, and then adding a fluorine source, an inorganic titanium source and 0.5-4 mol/L strong acid, wherein the molar ratio of silicon to fluorine is 1-40, and the molar ratio of silicon to titanium is 2-80; refluxing at 50-120 ℃, feeding titanium for 0.5-10 hours, filtering or centrifuging to obtain a solid after acid washing and titanium feeding, washing to be neutral, drying and grinding to obtain a Ti-MWW molecular sieve precursor;
(3) preparing a pore-enlarging Ti-MWW molecular sieve: and (3) placing the Ti-MWW molecular sieve precursor obtained in the step (2) into a polytetrafluoroethylene container, then adding an alkaline solution containing a surfactant, performing reflux treatment for 1-20 hours, then centrifuging or filtering out a solid, washing to be neutral, drying, roasting and grinding to obtain the pore-expanding Ti-MWW molecular sieve.
2. The method of preparing a reamed Ti-MWW molecular sieve as claimed in claim 1, characterized in that: in the step (1), the silicon source is one or more of tetraethyl orthosilicate, white carbon black, silica gel and silica sol; the seed crystal is one or more of ITQ-1, boron-containing MWW and boron-removed MWW.
3. The method of preparing a reamed Ti-MWW molecular sieve as claimed in claim 1, characterized in that: in the step (1), the organic amine template agent is one or more of piperidine, hexamethyleneimine and ethylenediamine.
4. The method of preparing a reamed Ti-MWW molecular sieve as claimed in claim 1, characterized in that: in the step (2), the fluorine source is one or more of hydrofluoric acid, ammonium fluoride and ammonium bifluoride.
5. The method of preparing a reamed Ti-MWW molecular sieve as claimed in claim 1, characterized in that: in the step (2), the inorganic titanium source is one or more of titanium tetrachloride, titanium sulfate, ammonium fluotitanate and fluotitanic acid.
6. The method of preparing a reamed Ti-MWW molecular sieve as claimed in claim 1, characterized in that: in the step (2), the strong acid is one or more of hydrochloric acid, sulfuric acid and nitric acid.
7. The method of preparing a reamed Ti-MWW molecular sieve as claimed in claim 1, characterized in that: the surfactant in the step (3) is one or more of sodium dodecyl sulfate, hexadecyl ammonium bromide and hexadecyl ammonium hydroxide; the alkaline solution is one or more of sodium hydroxide solution, ammonia water, tetraethylammonium hydroxide solution, tetrapropylammonium hydroxide solution and tetrabutylammonium hydroxide solution.
8. The method of preparing a reamed Ti-MWW molecular sieve as claimed in claim 1, characterized in that: in the step (3), the mass fraction of solute components in the alkaline solution is 5-25%; the mass ratio of the carrier, the surfactant and the alkaline solution is 1: (1-10) and (10-25).
9. The method of preparing a reamed Ti-MWW molecular sieve as claimed in claim 1, characterized in that: the reflux treatment temperature in the step (3) is 45-95 ℃.
10. The method of preparing a reamed Ti-MWW molecular sieve as claimed in claim 1, characterized in that: in the step (3), the roasting temperature is 450-650 ℃, and the roasting time is 3-15 hours.
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CN115770611A (en) * 2022-12-12 2023-03-10 大连龙缘化学有限公司 Preparation method and application of mesitylene catalyst prepared by isomerizing pseudocumene

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115770611A (en) * 2022-12-12 2023-03-10 大连龙缘化学有限公司 Preparation method and application of mesitylene catalyst prepared by isomerizing pseudocumene
CN115770611B (en) * 2022-12-12 2024-02-06 大连龙缘化学有限公司 Preparation method and application of catalyst for preparing mesitylene by pseudocumene isomerization

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