Preparation method and application of micron-sized GM-1 material

Abstract

The invention discloses a preparation method and application of a micron-sized GM-1 material. The preparation method of the material comprises the following steps: putting AlCl3 and 1H-pyrrole-2, 5-dicarboxylic acid into a reaction kettle, adding sodium formate and water, and uniformly mixing and stirring to obtain a reaction mixture; and heating the reaction mixture to react for 20-30 hours to obtain a white micron material, cooling to room temperature, filtering, washing and drying to obtain the hierarchical pore micron material. The synthesized material is used as a stationary phase in a capillary chromatographic column, and the separation degree of xylene isomer separation time site / para-site is up to 21.9. The synthesized material is used in a stainless steel packed column to obtain a gas-phase packed column, and the meta-position / para-position penetration separation degree of xylene isomers is up to 4.5. The invention provides a new solution for trace detection and efficient penetration separation of xylene isomers.

Description

Technical Field

[0001] The invention belongs to the technical field of chromatographic separation materials, and in particular relates to a preparation method and application of a micron-grade GM-1 material. Background Art

[0002] Xylene isomers include para-xylene, meta-xylene and ortho-xylene, which are important components of pyrolysis gasoline and catalytic reforming oil, and are commonly used in toluene disproportionation processes and as separate petrochemical feedstocks. In particular, para-xylene is the most valuable monomer in industry because it is used to make polyethylene terephthalate and polybutylene terephthalate, which are the basis for the production of polyester plastics and polyester fibers. Based on this, the industry has strict requirements on the purity of xylene isomers and the efficient separation of xylene isomers. Ortho-xylene isomers can be separated by distillation, so the challenge lies in the separation of para-xylene and meta-xylene. Therefore, the separation of xylene isomers is of great significance in the industrial field.

[0003] Separation of xylene isomers by distillation is an energy-intensive process because the boiling points of xylene isomers are almost the same. Currently, adsorption separation is an effective alternative method for separating xylene isomers, and zeolites play a leading role in the industry. However, due to limited porosity, structural adjustability and rigidity, traditional adsorbents have low selectivity and absorption capacity, and require the use of complex simulated moving bed technology with multiple bed lines and rotary valves. In addition, the high energy consumption of zeolite adsorbent regeneration is another disadvantage. The development of stable and high-performance adsorbents is an important research area for the effective separation of xylene isomers. Therefore, there is an urgent need to develop a porous material that is sensitive to xylene isomer molecules to achieve efficient detection and separation of xylene isomers. Summary of the invention

[0004] Purpose of the invention: To solve the above technical problems, the present invention provides a preparation method and application of a micron-sized GM-1 material, which can be used to achieve both trace detection of xylene isomers and large-scale separation of xylene isomers.

[0005] Technical solution: The method for preparing a micron-sized GM-1 material according to the present invention comprises the following steps:

[0006] (1) AlCl 3 and 1H-pyrrole-2,5-dicarboxylic acid are placed in a reaction kettle, sodium formate and water are added, and the mixture is mixed and stirred to obtain a reaction mixture;

[0007] (2) The reaction mixture in step (1) is heated to react for 20-30 hours to obtain a white micron material, which is then cooled to room temperature and filtered, washed, and dried to obtain a multi-level porous micron-sized GM-1 material.

[0008] Preferably, the concentration of aluminum chloride in the reaction mixture described in step (1) is 9 mg / mL to 11 mg / mL, the concentration of 1H-pyrrole-2,5-dicarboxylic acid is 9 mg / mL to 11 mg / mL, and the concentration of sodium formate is 9 mg / mL to 11 mg / mL.

[0009] Preferably, the temperature rising reaction in step (2) is a condensation reflux reaction heated to 100° C. in an oil bath.

[0010] Preferably, the reaction time in step (2) is 24 h.

[0011] Preferably, the washing process in step (2) is to first wash with DMF and then wash with ethanol. More preferably, the two detergents are used for washing three times each.

[0012] Preferably, the drying in step (2) is natural evaporation drying at room temperature.

[0013] The present invention also provides the use of micron-grade GM-1 material in the preparation of a capillary chromatographic column. The method for preparing the capillary chromatographic column comprises the following steps:

[0014] (1) ultrasonically dispersing the multi-level porous micron-sized GM-1 material in an organic solvent to obtain a mixed solution;

[0015] (2) using a syringe pump to push the mixed solution into the pretreated capillary column at a uniform speed to dynamically coat the inner wall of the capillary column;

[0016] (3) The capillary column is subjected to a programmed temperature aging treatment under an inert atmosphere, and after cooling to room temperature, a capillary gas chromatography column is obtained.

[0017] The capillary gas chromatography column is installed in a gas chromatograph and can perform sensitive detection and efficient separation of xylene isomers.

[0018] Preferably, the organic solvent in step (1) is methanol.

[0019] Preferably, the inert atmosphere in step (3) is one of nitrogen, helium or argon, or an atmosphere formed by mixing several of them in any proportion.

[0020] Preferably, the specific method of the programmed temperature aging treatment in step (3) is: the initial temperature is 20-50 degrees Celsius, the temperature is increased to 250 degrees Celsius at a rate of 2-10 degrees Celsius / minute, and maintained for 2-8 hours.

[0021] The present invention also provides an application of the micron-sized GM-1 material in the preparation of a gas-phase filling column. The preparation method of the gas-phase filling column comprises the following steps:

[0022] (1) subjecting the multi-level porous micron-sized GM-1 material to high-temperature vacuum degassing;

[0023] (2) sieving the degassed material using a sieve to obtain adsorbent particles of uniform size;

[0024] (3) Use a funnel to fill the particles into a stainless steel filling column and seal the end;

[0025] (4) The stainless steel filled column is subjected to a programmed temperature aging treatment under an inert atmosphere, and then cooled to room temperature to obtain the gas phase filled column.

[0026] The prepared gas phase filling column is installed at the rear end of the xylene isomer mixed steam, and can perform large-scale and efficient separation of xylene isomers.

[0027] Preferably, the inert atmosphere in step (4) is one of nitrogen, helium or argon, or an atmosphere formed by mixing several of them in any proportion.

[0028] Preferably, the specific method of the programmed temperature aging treatment in step (4) is: the initial temperature is 20-50°C, the temperature is increased to 150°C at a rate of 2°C / min to 10°C / min, and maintained for 12-18h.

[0029] Connect the capillary chromatography gas chromatography column to the gas chromatograph, connect the stainless steel gas phase filling column to the front end of the gas chromatograph and the rear end of the xylene isomer mixed vapor, set the gas chromatograph oven temperature and its retention time, carrier gas flow rate and filling column oil bath temperature, use the flow controller to carry the separation target into the filling column by the carrier gas, and the tail gas enters the gas chromatograph. Click to start the test and a few minutes later, the chromatographic peaks of the corresponding separations of xylene isomers can be obtained.

[0030] Beneficial effects: Compared with the prior art, the technical solution of the present invention has the following significant advantages: (1) The micron-sized GM-1 material prepared by the present invention as an adsorbent filled column achieves extremely high penetration separation of meta-xylene and para-xylene, with a meta / para separation of up to 4.5; as a stationary phase, it also achieves baseline separation of the three xylene isomers, with a meta / para separation of up to 21.9, and the prepared gas chromatography column and stainless steel filled column have extremely high stability and repeatability; (2) The micron-sized GM-1 material has a good penetration separation of meta-xylene and para-xylene. The second-order adsorption characteristics show that the adsorption of m-xylene at 30°C is a record high of 4.0 mmol / g; (3) The material particles have a large specific surface area, which is conducive to the adsorption of the target. The material size is suitable and uniform, and can be used as a stationary phase of a gas chromatography column or as a filling adsorbent for a gas phase filling column. It can be used to achieve both trace detection of xylene isomers and large-scale separation of xylene isomers. It has a wide range of applications and is a very promising material for the detection and separation of xylene isomers. It is of great significance in the fields of industry and environmental science. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a scanning electron microscope image of the micron-sized GM-1 material in Example 1 of the present invention;

[0032] Figure 2 This is the powder XRD pattern of the micron-sized GM-1 material in Example 2 of the present invention;

[0033] Figure 3 This is a scanning electron microscope image of a chromatographic column coated with a micron-sized GM-1 material in Example 3 of the present invention;

[0034] Figure 4 This is a single component vapor adsorption diagram of m-xylene of the micron-sized GM-1 material in Example 5 of the present invention;

[0035] Figure 5 It is a chromatographic separation diagram of the micron-sized GM-1 stationary phase in Example 3 of the present invention and a penetration separation diagram of the adsorbent-filled column in Example 6;

[0036] Figure 6 The gas chromatogram obtained by separating xylene isomers using the capillary gas chromatographic column prepared in Example 3 of the present invention and the penetration separation graph obtained by penetrating and separating xylene isomers using the stainless steel gas phase filling column prepared in Example 5; wherein Figure 6 a The penetration separation diagram obtained by separating p-xylene and m-xylene. Figure 6 b The penetration separation diagram obtained by separating m-xylene and o-xylene. Figure 6 c is the penetration separation diagram obtained by separating p-xylene and o-xylene. Figure 6d is a gas chromatogram obtained by performing gas chromatography separation of xylene isomers using the capillary chromatographic column prepared in Example 3. DETAILED DESCRIPTION

[0037] The technical solution of the present invention is further described in detail below through specific examples, but it is necessary to point out that the following examples are only used to describe the content of the invention and do not constitute a limitation on the protection scope of the present invention. The gas chromatograph used in the present invention is Agilent GC7890B, and the reagents used are analytical grade or chromatographic grade.

[0038] Example 1

[0039] A method for preparing a micron-sized GM-1 material comprises the following steps:

[0040] (1) In a 50 mL round-bottom flask, add 133 mg aluminum chloride, 128 mg H 2 PyDC, 120 mg of sodium formate and 15 ml of water, the mixture was sonicated until clear and transparent, the oil bath was heated to 100 ° C, and condensed and refluxed at this temperature for 24 hours, then the oil bath was stopped and the round-bottom flask was cooled to room temperature;

[0041] (2) The obtained product was first washed three times with DMF, then washed three times with ethanol, and then naturally evaporated and dried at room temperature to obtain a micron-sized GM-1 material.

[0042] Figure 1 This is a scanning electron microscope image of micron-sized GM-1 material. From the image, we can see that the width of the material is several microns and the morphology is square;

[0043] Figure 5 This is the single component vapor adsorption diagram of m-xylene of micron-sized GM-1 material. It can be seen from the figure that micron-sized GM-1 has second-order adsorption characteristics for m-xylene, and the adsorption amount is as high as 4.0mmol / g

[0044] Example 2

[0045] A method for preparing a micron-sized GM-1 material comprises the following steps:

[0046] (3) In a 50 mL round-bottom flask, 125 mg of aluminum chloride, 130 mg of H2PyDC, 130 mg of sodium formate and 18 ml of water were added, the mixture was sonicated until clear and transparent, the oil bath was heated to 100°C, and condensation reflux was maintained at this temperature for 20 hours, then the oil bath was stopped and the round-bottom flask was cooled to room temperature;

[0047] (4) The obtained product was first washed three times with DMF, then washed three times with ethanol, and then naturally evaporated and dried at room temperature to obtain a micron-sized GM-1 material.

[0048] Figure 2 This is the powder XRD diagram of micron-sized GM-1 material. It can be seen from the figure that the synthesized micron-sized GM-1 has a high degree of crystallinity, which is consistent with the simulated structure, proving the successful synthesis of GM-1.

[0049] Example 3

[0050] The application of micron-sized GM-1 material in the preparation of capillary chromatographic columns comprises the following steps:

[0051] (1) ultrasonically dispersing the porous micron material in methanol to obtain a mixed solution;

[0052] (2) using a syringe pump to push the mixed solution into the pretreated capillary column at a uniform speed to dynamically coat the inner wall of the capillary column;

[0053] (3) The capillary column was subjected to a programmed temperature aging treatment in a nitrogen inert atmosphere. The specific parameters of the programmed temperature were as follows: an initial temperature of 20 degrees Celsius, a temperature increase of 10 degrees Celsius / minute to 250 degrees Celsius, and a holding temperature of 8 hours. After cooling to room temperature, a capillary gas chromatography column was obtained.

[0054] Figure 3 This is a scanning electron microscope image of the micron-sized GM-1 material. It can be seen from the image that the micron-sized GM-1 is evenly coated on the inner wall of the capillary, and the coating process does not affect the size and morphology of the micron-sized GM-1. The capillary gas chromatography column is installed in a gas chromatograph, which can perform sensitive detection and efficient separation of xylene isomers.

[0055] Example 4

[0056] The application of micron-sized GM-1 material in the preparation of capillary chromatographic columns comprises the following steps:

[0057] (1) ultrasonically dispersing the multi-level porous micron-sized GM-1 material in methanol to obtain a mixed solution;

[0058] (2) using a syringe pump to push the mixed solution into the pretreated capillary column at a uniform speed to dynamically coat the inner wall of the capillary column;

[0059] (3) The capillary column was subjected to a programmed temperature aging treatment in a helium inert atmosphere. The specific parameters of the programmed temperature were as follows: an initial temperature of 50 degrees Celsius, a temperature increase of 2 degrees Celsius / minute to 250 degrees Celsius, and a holding temperature of 2 hours. After cooling to room temperature, a capillary gas chromatography column was obtained.

[0060] The capillary gas chromatography column is installed in a gas chromatograph and can perform sensitive detection and efficient separation of xylene isomers.

[0061] Example 5

[0062] The application of micron-sized GM-1 material in the preparation of gas phase filling column, the preparation method of gas phase filling column comprises the following steps:

[0063] (1) subjecting the multi-level porous micron-sized GM-1 material to high-temperature vacuum degassing;

[0064] (2) sieving the degassed material using a sieve to obtain adsorbent particles of uniform size;

[0065] (3) Use a funnel to fill the particles into a stainless steel filling column and seal the end;

[0066] (4) The stainless steel packed column is subjected to a programmed temperature aging treatment in a nitrogen inert atmosphere, wherein the specific parameters of the programmed temperature are as follows: an initial temperature of 20° C., the temperature is increased to 150° C. at a rate of 10° C. / min, maintained for 18 h, and then cooled to room temperature to obtain the gas phase packed column.

[0067] The prepared gas phase filling column is installed at the rear end of the xylene isomer mixed steam, and can perform large-scale and efficient separation of xylene isomers.

[0068] Example 6

[0069] The application of micron-sized GM-1 material in the preparation of gas phase filling column, the preparation method of gas phase filling column comprises the following steps:

[0070] (1) subjecting the multi-level porous micron-sized GM-1 material to high-temperature vacuum degassing;

[0071] (2) sieving the degassed material using a sieve to obtain adsorbent particles of uniform size;

[0072] (3) Use a funnel to fill the particles into a stainless steel filling column and seal the end;

[0073] (4) The stainless steel filling column is subjected to a programmed temperature aging treatment in an inert atmosphere of a mixture of nitrogen and argon. The specific parameters of the programmed temperature are as follows: an initial temperature of 50° C., heating to 150° C. at a rate of 2° C. / min, maintaining for 12 h, and then cooling to room temperature to obtain the gas phase filling column.

[0074] The prepared gas phase filling column is installed at the rear end of the xylene isomer mixed steam, and can perform large-scale and efficient separation of xylene isomers.

[0075] Figure 5The chromatographic separation diagram of the micron-sized GM-1 stationary phase in Example 3 of the present invention and the penetration separation diagram as an adsorbent in Example 6 show that the micron-sized GM-1 is used as a gas chromatography separation stationary phase, and the chromatographic peaks obtained by separation are narrow and sharp, which can completely separate the xylene isomers. The micron-sized GM-1 is used as an adsorbent, and the separation window of the penetration separation diagram obtained by separation is very large, which can efficiently separate xylene isomers in large quantities. This shows that the micron-sized GM-1 material synthesized by the present invention has good application prospects in the fields of gas chromatography and penetration separation;

[0076] The micron-sized materials prepared in the above examples were physically characterized by SEM and single-component vapor adsorption. Figure 1 ) It is known that the material has uniform size and is three-dimensional particles at the micron level. The cross-sectional SEM image of the column ( Figure 3 ) shows that the multi-level micron particles are evenly embedded in the inner wall of the capillary column. Figure 4 The nitrogen adsorption spectrum shows that the material has a large specific surface area and high porosity, and the BET specific surface area value is 1073.79m 2 / g, strong adsorption capacity. Single component vapor adsorption spectrum ( Figure 5 ) shows that this micron material has a strong adsorption capacity for xylene isomers, and the material has a second-order adsorption characteristic for meta-xylene isomers with a large adsorption capacity. Figure 6 The gas chromatogram obtained by separating a xylene mixture using the capillary gas chromatographic column prepared in Example 3 and the penetration separation diagram obtained by penetrating and separating a xylene mixture using the stainless steel gas phase packed column prepared in Example 5, the meta / para chromatographic separation is as high as 21.9, and the meta / para penetration separation is as high as 4.5. The above results all indicate that the material can be used to achieve both trace detection of xylene isomers and large-scale separation of xylene isomers, and has a good application prospect for separating isomers.

[0077] In summary, the present invention provides a method for preparing a micron-sized GM-1 material. The present invention applies micron-sized GM-1 to gas chromatography separation and penetration separation for the first time. The particle size of micron-sized GM-1 is small and uniform, and it can be used as a capillary chromatographic column stationary phase and as a stainless steel meteorological filling column filling adsorbent. The thermodynamic forces and diffusion rates of xylene isomers in the micron-sized GM-1 stationary phase are significantly different. Micron-sized GM-1 exhibits good separation performance in gas chromatography separation. The adsorption amounts of xylene isomers in the micron-sized GM-1 adsorbent vary greatly, so it exhibits excellent penetration separation performance. The present invention uses a solvent thermal synthesis method, and the equipment is simple, which can be used as a reference for the synthesis of other micron-sized MOFs. The resulting material is small in size, and has uniform morphology and size, and is a very potential gas chromatography stationary phase.

Claims

1. A method for preparing micron-sized GM-1 material, characterized in that: The following steps are involved: (1) placing AlCl3 and 1H-pyrrole-2,5-dicarboxylic acid in a reaction kettle, adding sodium formate and water, and mixing and stirring to obtain a reaction mixture; (2) The reaction mixture in step (1) is heated to react for 20-30 hours to obtain a white micron material, which is then cooled to room temperature and filtered, washed, and dried to obtain a multi-level porous micron-sized GM-1 material.

2. The method for preparing the micron-sized GM-1 material according to claim 1, characterized in that: The concentration of aluminum chloride in the reaction mixture described in step (1) is 9 mg / mL to 11 mg / mL, the concentration of 1H-pyrrole-2,5-dicarboxylic acid is 9 mg / mL to 11 mg / mL, and the concentration of sodium formate is 9 mg / mL to 11 mg / mL.

3. The method for preparing the micron-sized GM-1 material according to claim 1, characterized in that: The temperature-raising reaction in step (2) is a condensation reflux reaction in which the oil bath is heated to 100°C.

4. The method for preparing the micron-sized GM-1 material according to claim 1, characterized in that: The washing process described in step (2) is to first wash with DMF and then wash with ethanol. More preferably, the two detergents are used for washing three times each.

5. The method for preparing the micron-sized GM-1 material according to claim 1, characterized in that: The drying in step (2) is natural evaporation drying at room temperature.

6. Use of the micron-sized GM-1 material according to claim 1 in the preparation of a capillary chromatographic column, characterized in that: Capillary column preparation includes the following steps: (1) ultrasonically dispersing the multi-level porous micron-sized GM-1 material in methanol to obtain a mixed solution; (2) using a syringe pump to push the mixed solution into the pretreated capillary column at a uniform speed to dynamically coat the inner wall of the capillary column; (3) The capillary column is subjected to a programmed temperature aging treatment under an inert atmosphere, and after cooling to room temperature, a capillary gas chromatography column is obtained.

7. The use of the micron-sized GM-1 material according to claim 6 in the preparation of a capillary chromatographic column, characterized in that: The inert atmosphere in step (3) is one of nitrogen, helium or argon, or a mixture of several of them in any proportion.

8. The use of the micron-sized GM-1 material according to claim 6 in the preparation of a capillary chromatographic column, characterized in that: The specific method of the programmed temperature aging treatment in step (3) is: the initial temperature is 20-50 degrees Celsius, and the temperature is increased to 250 degrees Celsius at a rate of 2-10 degrees Celsius / minute, and maintained for 2-8 hours.

9. Use of the micron-sized GM-1 material according to claim 1 in the preparation of a gas phase filling column, characterized in that: The preparation of the gas phase packed column comprises the following steps: (1) High temperature vacuum degassing of the multi-level porous micron-sized GM-1 material; (2) sieving the degassed material using a sieve to obtain adsorbent particles of uniform size; (3) Use a funnel to fill the particles into a stainless steel filling column and seal the end; (4) The stainless steel filled column is subjected to a programmed temperature aging treatment under an inert atmosphere, and then cooled to room temperature to obtain the gas phase filled column.

10. The use of the micron-sized GM-1 material according to claim 9 in the preparation of a gas phase filling column, characterized in that: The specific method of the programmed temperature aging treatment in step (4) is: the initial temperature is 20-50°C, the temperature is increased to 150°C at a rate of 2°C / min to 10°C / min, and maintained for 12-18h.

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