WO2020227886A1

WO2020227886A1 - Method for rapidly preparing high crystallinity ecr-1 molecular sieve

Info

Publication number: WO2020227886A1
Application number: PCT/CN2019/086618
Authority: WO
Inventors: 王磊; 郭鹏; 樊栋; 田鹏; 刘中民
Original assignee: 中国科学院大连化学物理研究所
Priority date: 2019-05-13
Filing date: 2019-05-13
Publication date: 2020-11-19

Abstract

Disclosed in the present application is a method for rapidly preparing a high crystallinity ECR-1 molecular sieve, comprising the following steps: mixing raw materials containing a T element source, an A element source, an alkali source OH^-, an organic template agent R, and water to obtain an initial mixture; and (2) hydrothermally crystallising the initial mixture obtained in step (1) to obtain an ECR-1 molecular sieve; the T element source is at least one of IV A group elements; the A element source is at least one of III A group elements; the alkali source OH^- is an alkali metal source and/or an alkali earth metal source; and the organic template agent R is at least one of the compounds having the chemical structures represented by formula I and formula II. The present preparation method is simple, has convenient operation, good repeatability, and high efficiency, can rapidly synthesise an ECR-1 molecular sieve, and is suitable for industrial production.

Description

A method for quickly preparing ECR-1 molecular sieve with high crystallinity

Technical field

The invention belongs to the technical field of inorganic materials, and specifically relates to a method for preparing ECR-1 molecular sieve.

Background technique

ECR-1 (molecular sieve structure code: EON) molecular sieve is a microporous crystalline silica-alumina molecular sieve. It has a two-dimensional twelve-membered ring and eight-membered ring pore structure. The composition structure can be disassembled into MOR molecular sieve crystal layer and MAZ Molecular sieve crystal layer. At the same time, ECR-1 molecular sieve and molecular sieve have high thermal stability, hydrothermal stability and adjustable acidity. Therefore, ECR-1 molecular sieve shows high practical value in the shape-selective catalysis of small molecules, carbonylation, dimethyl ether carbonyl, aromatic alkylation, toluene disproportionation and long-chain alkane isomerization.

ECR-1 molecular sieve has been reported to be relatively difficult to synthesize. The reported synthetic difficulties are mainly reflected in: 1) The use of expensive organic templates such as dimethyl-diethylammonium (US4657748A), methyl- Triethylammonium (US5206005A) or double-headed quaternary ammonium salt containing adamantane 2) even when using cheap organic template tetramethylammonium hydroxide (Chem Mater, 18, 76, 2006) or template-free synthesis (reaction time It takes 5-13 days to improve the expensive raw materials used and shorten the synthesis time is an effective way to expand the practical use of ECR-1 molecular sieve molecular sieve materials. Compared with the conventional and complicated ECR-1 preparation method, the template used in this method is cheap And the repeatability is better, the time is shortened from the original 7-15 days to 1-3 days, and the silicon-to-aluminum ratio of the obtained molecular sieve is increased from 3.5 to 5.0.

Summary of the invention

According to one aspect of the present application, a method for preparing ECR-1 molecular sieve with good repeatability and high efficiency is provided. The preparation method is simple, easy to operate, can quickly synthesize ECR-1 molecular sieve, and is suitable for industrial production.

The method for rapidly preparing ECR-1 molecular sieve with high crystallinity is characterized in that it comprises the following steps:

(1) containing the source of element T, A element source, an alkali source of OH ^- mixing, the organic template R a raw material and water to obtain an initial mixture;

(2) Hydrothermally crystallize the initial mixture obtained in step (1) to obtain the ECR-1 molecular sieve;

Wherein, the source of the T element is selected from at least one of group IV and A elements;

The source of the A element is selected from at least one of group III and A elements;

The alkali source OH ^- is an alkali metal source and/or alkaline earth metal source;

The organic template R is selected from at least one compound having the chemical structural formula shown in Formula I and Formula II:

In formula I, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ , and R _{9 are} independently selected from at least one of H and C ₁ to C ₁₀ hydrocarbon groups.

In formula I, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ , and R _{9 are} independently selected from at least one of H and C ₁ to C ₅ hydrocarbon groups.

Optionally, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ , and R _{9 are} independently selected from at least one of H, C ₁ ～C ₁₀ branched alkyl groups Kind.

Optionally, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ , and R _{9 are} independently selected from H, C ₁ ～C ₁₀ branched alkyl groups At least one of.

Optionally, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ , and R _{9 are} independently selected from at least one of H, C ₁ ～C ₅ branched alkyl groups Kind.

Optionally, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ , and R _{9 are} independently selected from H, C ₁ ～C ₅ branched alkyl groups At least one of.

Optionally, the molar ratio of the T element source, A element source, alkali source OH ⁻ , organic template R and H ₂ O in the initial mixture is:

TO ₂ /A ₂ O ₃ is 10～999,

OH ^- / TO ₂ 0.01 to 1.0,

H ₂ O/TO ₂ is 3～4000,

R/TO ₂ is 0.05～1.0;

Among them, the source of T element is calculated by the number of moles of TO ₂ , the source of A element is calculated by the number of moles of A ₂ O ₃ , the alkali metal source OH ^- is calculated by the number of moles of OH ^- element contained, and the organic template R is calculated by itself H ₂ O is calculated by its own moles.

Optionally, the lower limit of the range of the molar ratio of R/TO ₂ in the initial mixture is selected from 0.06:1, 0.07:1, 0.08:1, 0.09:1, 0.1:1, or 0.12:1, and the upper limit is selected from 0.15: 1. 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1 or 1.0:1.

Optionally, the molar ratio of R/TO ₂ in the initial mixture is 0.08-0.8:1.

Alternatively, the initial mixture of OH ^- / TO ₂ molar ratio in the range of the lower limit of 0.01 is selected from: 1,0.02: 0.03,0.04: 1,0.045: 1 or 0.05: 1, the upper limit of 0.5 is selected from: 1, 0.6 :1, 0.65:1, 0.7:1 or 0.8:1.

Optionally, the lower limit of the molar ratio range of TO ₂ /A ₂ O ₃ in the initial mixture is selected from 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 120, 150, 180, 200, 250, 300, 400, 500, 600, 700, 800 or 900; the upper limit is selected from 20, 30, 40, 50, 60, 70, 80, 90, 100, 120, 150, 180, 200, 250, 300 , 400, 500, 600, 700, 800, 900, or 999.

Optionally, the lower limit of the molar ratio range of H ₂ O/TO ₂ in the initial mixture is selected from 3, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 150 , 200, 500, 800, 1000, 1500, 2000, 3000 or 4000; the upper limit is selected from 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 150, 200, 500, 800, 1000, 1500, 2000 or 3000.

Specifically, the method includes the following steps:

(1) The oxide of tetravalent TO _2, trivalent oxide Y ₂ O _3, an alkali source OH ^-, an organic templating agent R1, R2, and mixed water obtained preliminary mixing thereof;

(2) Place the mixture obtained in step (1) for a hydrothermal crystallization reaction at 140-200°C for 24-480 hours to obtain the ECR-1 molecular sieve;

Among them, the organic template is one or two of R1 or R2;

Wherein, the molar ratio of TO ₂ , Y ₂ O ₃ , R1, R2 and H ₂ O in the initial mixture is:

TO ₂ /Y ₂ O ₃ is 10～999,

OH ^- / TO ₂ 0.01 to 1.0,

H ₂ O/TO ₂ is 3～4000,

R1+R2/TO ₂ is 0.05～1.0;

R1 is selected from at least one compound having the chemical structural formula shown in Formula I:

R2 is selected from at least one of compounds having the chemical structural formula shown in Formula II and compounds having the chemical structural formula shown in Formula II:

Among them, n is 0-7.

Optionally, the source of T element is selected from at least one of a silicon source, a germanium source, and a tin source;

The source of element A is selected from at least one of an aluminum source, a boron source, and a gallium source;

The alkali source OH ^-is selected from at least one of alkali metal hydroxides and alkaline earth metal hydroxides.

Optionally, the silicon source is selected from at least one of ethyl orthosilicate, silica gel, silicic acid, white carbon black, silica sol, water glass, and diatomaceous earth;

The germanium source is germanium oxide;

The tin source is selected from at least one of tin oxide and tin chloride;

The aluminum source is selected from at least one of aluminum isopropoxide, sodium aluminate, aluminum foil, aluminum sulfate, aluminum chloride, aluminum nitrate, aluminum hydroxide, boehmite, and pseudo-boehmite;

The boron source is selected from at least one of boric acid, sodium borate, and boron oxide;

The gallium source is selected from at least one of gallium nitrate and gallium trichloride;

The alkali source OH ^-is selected from at least one of sodium hydroxide, potassium hydroxide and cesium hydroxide.

Optionally, in formula I, R _{1 is} selected from at least one of C ₁ to C ₄ hydrocarbon groups; R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ , and R ₉ are H .

Optionally, the organic template R is pyrrolidine and/or butylpyrrolidine.

Optionally, the organic template R is pyrrolidine.

Optionally, the organic template R is butylpyrrolidine.

Optionally, the organic template R is a mixture of pyrrolidine and butylpyrrolidine, and the molar ratio of pyrrolidine to butylpyrrolidine is 10-100:0-90.

Optionally, the molar ratio of the pyrrolidine and butylpyrrolidine is 10:90, 20:80, 30:70, 40:60, 50:50, 60:90, 70:90, 80:90, 90 : Any ratio of 90, 100:0 and the range value between any two ratios.

Optionally, step (1) includes: adding a T element source to a mixture of A element source, alkali source OH ⁻ , organic template R and water, and mixing to obtain an initial mixture.

Optionally, the conditions for the hydrothermal crystallization are: hydrothermal crystallization reaction at 100-200°C for 24 to 480 hours.

Optionally, the conditions for the hydrothermal crystallization are: hydrothermal crystallization reaction at 100-200°C for 24 to 72 hours.

Optionally, step (2) includes: placing the initial mixture obtained in step (1) for a hydrothermal crystallization reaction at 100-200°C for 24-480 hours, and the obtained product is separated, washed, and dried to obtain the ECR-1 molecular sieve.

Another aspect of the present application provides an ECR-1 molecular sieve, characterized in that it is prepared according to any one of the above methods; the ECR-1 molecular sieve has an atomic ratio of silicon to aluminum of 3.5-8.

Optionally, the lower limit of the silicon to aluminum atomic ratio of the ECR-1 molecular sieve is selected from 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.5, 5, 5.1, 5.2, 5.3, 5.4, 5.5, 5.8, 6, 6.5 , 7 or 7.5; the upper limit is selected from 3.6, 3.7, 3.8, 3.9, 4, 4.5, 5, 5.1, 5.2, 5.3, 5.4, 5.5, 5.8, 6, 6.5, 7, 7.5 or 8.

Optionally, the ECR-1 molecular sieve is regular rod-shaped particles with a particle size of 10-15 μm and a width of 1-3 μm.

Optionally, the ECR-1 molecular sieve has a molecular sieve molecular sieve structure containing directional distribution.

Optionally, the XRD spectrum of the ECR-1 molecular sieve includes diffraction peaks at the following positions:

2θ=5.90-5.95,

2θ=6.70-6.80,

2θ=8.3-8.36,

2θ=9.70-9.77,

2θ=10.15-10.30,

2θ=10.30-10.35,

2θ=12.15-12.18,

2θ=13.10-13.13,

2θ=15.04-15.08,

All conditions related to the numerical range in this application can be independently selected from any point value within the numerical range.

In this application, "C ₁ to C ₁₀ "and the like all refer to the number of carbon atoms contained in the group.

In this application, "alkyl" is a group formed by the loss of any hydrogen atom on the molecule of an alkane compound.

In this application, "hydrocarbon group" refers to a group formed after a hydrogen atom on a carbon atom is lost in a hydrocarbon molecule. The hydrocarbons are carbohydrates, for example, alkanes, alkenes and alkynes are all hydrocarbons.

The beneficial effects that this application can produce include:

1) The preparation method of ECR-1 molecular sieve provided by this application is simple, convenient to operate, reproducible, high-efficiency, rapid synthesis of ECR-1 molecular sieve, and suitable for industrial production.

2) The ECR-1 molecular sieve provided by this application not only has a regular appearance and has a molecular sieve pore structure with directional distribution, but the extremely high crystallinity and relatively abundant contact area improve the screening utilization efficiency of this type of molecular sieve.

Description of the drawings

Figure 1 shows the XRD spectrum of the sample of Example 1.

Figure 2 is a scanning electron micrograph of the sample of Example 1.

Figure 3 is a scanning electron microscope photograph of a sample of Comparative Example 1.

Detailed ways

The application will be described in detail below with reference to the embodiments, but the application is not limited to these embodiments.

Unless otherwise specified, the raw materials in the examples of this application are all purchased through commercial channels.

In the examples, the product silicon-to-aluminum molar ratio is Si/Al atomic ratio.

The analysis method in the embodiment of the present invention is as follows:

X'Pert PRO X-ray diffractometer [Cu target, Kα radiation source (λ=0.15418nm), voltage 40KV, current 40mA] from PANalytical, the Netherlands, was used for X-ray powder diffraction phase analysis (XRD).

Hitachi (SU8020) scanning electron microscope was used for SEM topography analysis.

Example 1

Molar ratio of the initial gel formulation _{_{_{below: SiO 2 / Al 2 O 3}}} = 30, OH - / SiO 2 = 0.8, (R1 + R2) / SiO 2 = 0.2, H 2 O / SiO ₂ ratio = 30 Pseudo-boehmite, sodium hydroxide, pyrrolidine and butylpyrrolidine (the molar ratio of pyrrolidine to butylpyrrolidine is 50:50) were dissolved in deionized water, and then the silica sol was added under constant stirring . Then, the above mixture was put into a 100ml crystallization kettle and reacted at 150°C for 72 hours.

The cooled reaction solution was allowed to stand in a water bath for 2 hours, and after obvious stratification occurred, the off-white solid in the lower layer was ECR-1 molecular sieve molecular sieve, which was separated, washed, dried, and roasted (calcination temperature 550℃, After calcination time (8 hours), XRD analysis and SEM characterization were carried out. The XRD spectrum is shown in Figure 1, and the SEM images are shown in Figures 2 and 3. Figures 1 to 3 confirm that the synthesized product is a regular rod-shaped ECR-1 molecular sieve with a molar ratio of silicon to aluminum of 5.0; the particle size is 10μm, the width is about 2μm, and the number is ECR-1-1. The yield of ECR-1-1 is 70% based on the weight of silica.

Example 2-9

The specific ingredient ratio and crystallization conditions are shown in Table 1, and the specific ingredient process is the same as in Example 1.

The prepared sample was subjected to XRD analysis, and the data results were close to Table 2, that is, the peak position and shape were the same, and the relative kurtosis of the peak fluctuated within ±10% depending on the preparation conditions, indicating that the prepared product had the characteristics of ECR-1 structure.

Table 1 Ingredients and crystallization conditions for molecular sieve preparation

Table 2 XRD results of the sample of Example 1

Comparative example 1

Sodium hydroxide, tetramethylammonium hydroxide, sodium aluminate water, white carbon were mixed, prepared according to the following molar _{_{_{ratio: SiO 2 / Al 2 O 3}}} = 20, OH - / SiO 2 = 0.6, R / SiO ₂ =0.6, H ₂ O/SiO ₂ =40. Then the mixture was stirred in a 50°C water bath to a uniform gel, and was aged for 12 hours while stirring. Then the gel is transferred to a hydrothermal crystallization kettle, heated to 160 degrees, hydrothermally crystallized for 168 hours, then cooled naturally, filtered and dried to obtain the original molecular sieve molecular sieve powder. XRD test confirmed that it is ECR-1 molecular sieve molecular sieve, the molar ratio of silicon to aluminum is 3.5, and the morphology observed by low magnification SEM is rod-shaped small crystal aggregates (Figure 3), the particle size is 0.1-3μm. Based on the weight of the charged silica, the yield of the ECR-1 molecular sieve is 50%.

Comparative Example 1 shows that the synthesis and preparation of EON zeolite by the method publicly reported earlier in the literature takes a long time, the crystallinity is low, and the yield is also low.

The above are only a few embodiments of the application, and do not limit the application in any form. Although the application is disclosed as above with preferred embodiments, it is not intended to limit the application. Anyone familiar with the profession, Without departing from the scope of the technical solution of the present application, making some changes or modifications using the technical content disclosed above is equivalent to an equivalent implementation case and falls within the scope of the technical solution.

Claims

A method for quickly preparing ECR-1 molecular sieve with high crystallinity, which is characterized in that it comprises the following steps:

(1) containing the source of element T, A element source, an alkali source of OH - mixing, the organic template R a raw material and water to obtain an initial mixture;

(2) Hydrothermally crystallize the initial mixture obtained in step (1) to obtain the ECR-1 molecular sieve;

Wherein, the source of T element is selected from at least one of group IV and A elements;

The source of the A element is selected from at least one of group III and A elements;

The alkali source OH - is an alkali metal source and/or alkaline earth metal source;

The organic template R is selected from at least one compound having the chemical structural formula shown in Formula I and Formula II:

In formula I, R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , and R 9 are independently selected from at least one of H and C 1 to C 10 hydrocarbon groups.
The method according to claim 1, wherein, T element source of the initial mixture, A element source, an alkali source of OH -, and the organic template R a molar ratio of H 2 O:

TO 2 /A 2 O 3 is 10～999,

OH - / TO 2 0.01 to 1.0,

H 2 O/TO 2 is 3～4000,

R/TO 2 is 0.05～1.0;

Wherein, T element source to the TO 2 moles, A element source to moles of A 2 O 3, the alkali source OH - OH contained in its - in moles of the organic templating agent in its own molar R Count, H 2 O is counted by its own moles.
The method according to claim 1, wherein the source of T element is selected from at least one of a silicon source, a germanium source, and a tin source;

The source of element A is selected from at least one of an aluminum source, a boron source, and a gallium source;

The alkali source OH -is selected from at least one of alkali metal hydroxides and alkaline earth metal hydroxides.
The method according to claim 3, wherein the silicon source is selected from at least one of tetraethyl orthosilicate, silica gel, silicic acid, white carbon black, silica sol, water glass, and diatomaceous earth;

The germanium source is germanium oxide;

The tin source is selected from at least one of tin oxide and tin chloride;

The aluminum source is selected from at least one of aluminum isopropoxide, sodium aluminate, aluminum foil, aluminum sulfate, aluminum chloride, aluminum nitrate, aluminum hydroxide, and pseudo-boehmite;

The boron source is selected from at least one of boric acid, sodium borate, and boron oxide;

The gallium source is selected from at least one of gallium nitrate and gallium trichloride;

The alkali source OH -is selected from at least one of sodium hydroxide, potassium hydroxide and cesium hydroxide.
The method according to claim 1, wherein in formula I, R 1 is selected from at least one of C 1 to C 4 hydrocarbon groups; R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 and R 9 are H.
The method according to claim 1, wherein the organic template R is pyrrolidine and/or butylpyrrolidine.
The method according to claim 1, wherein the organic template R is a mixture of pyrrolidine and butylpyrrolidine, and the molar ratio of pyrrolidine to butylpyrrolidine is 10-100:0-90.
The method according to claim 1, wherein step (1) comprises: adding a T element source to a mixture of A element source, alkali source OH − , organic template R and water, and mixing to obtain an initial mixture.
The method of claim 1, wherein the hydrothermal crystallization conditions are: hydrothermal crystallization at 100-200°C for 24-480 hours.
The method according to claim 1, wherein the conditions of the hydrothermal crystallization are: hydrothermal crystallization at 100-200°C for 24-72 hours.
An ECR-1 molecular sieve, characterized in that it is prepared according to the method of any one of claims 1 to 9;

The silicon-to-aluminum atomic ratio of the ECR-1 molecular sieve is 3.5-8.
The ECR-1 molecular sieve according to claim 11, wherein the ECR-1 molecular sieve is regular rod-shaped or needle-shaped particles with a particle size of 10-15 μm and a width of 1-3 μm.