Preparation method and application of micrometer-scale GM-1 material

Abstract

The application discloses a preparation method and application of a micrometer-scale GM-1 material. The material preparation steps are as follows: AlCl3 and 1H-pyrrole-2,5-dicarboxylic acid are placed in a reaction kettle, sodium formate and water are added, and the mixture is uniformly stirred to obtain a reaction mixture; then the reaction mixture is warmed and reacted for 20-30 hours to obtain a white micrometer material, and after cooling to room temperature, the micrometer material is filtered, washed and dried to obtain a multi-stage micrometer material. The material obtained by synthesis is used in a capillary chromatographic column as a stationary phase, and the ortho / para separation degree of xylene isomers is up to 21.9. The material obtained by synthesis is used in a stainless steel packed column to obtain a gas phase packed column, and the meta / para penetration separation degree of xylene isomers is up to 4.5. The application provides a new solution for the trace detection and high-efficiency penetration separation of xylene isomers.

Description

Technical Field

[0001] This invention belongs to the field of chromatographic separation materials technology, specifically relating to a method for preparing and applying a micron-sized GM-1 material. Background Technology

[0002] Xylene isomers, including para-xylene, m-xylene, and o-xylene, are important components of pyrolysis gasoline and catalytic reforming oils, commonly used in toluene disproportionation processes and as standalone petrochemical feedstocks. Para-xylene, in particular, is the most valuable monomer industrially because it is used in the manufacture of polyethylene terephthalate (PET) and polybutylene terephthalate (PET), the basis for the production of polyester plastics and polyester fibers. Therefore, the industry has stringent requirements for the purity of xylene isomers and the efficient separation of xylene isomers. While o-xylene isomers can be separated by distillation, the challenge lies in separating para-xylene and m-xylene. Thus, the separation of xylene isomers is of great significance in the industrial field.

[0003] Distillation separation of xylene isomers is an energy-intensive process because the boiling points of xylene isomers are almost identical. Currently, adsorption separation is an effective alternative, with zeolites playing a dominant role in industry. However, traditional adsorbents suffer from low selectivity and absorption capacity due to limited porosity, structural tunability, and rigidity, requiring complex simulated moving bed technology with multiple bed lines and rotary valves. Furthermore, the high energy consumption of zeolite adsorbent regeneration is another drawback. Developing stable and high-performance adsorbents is an important research area for the efficient separation of xylene isomers. Therefore, there is an urgent need to develop porous materials 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-mentioned technical problems, the present invention provides a method for preparing and applying micron-sized GM-1 material, which can be used for both trace detection of xylene isomers and large-scale separation of xylene isomers.

[0005] Technical solution: The present invention provides a method for preparing micron-sized GM-1 material, comprising the following steps:

[0006] (1) Place AlCl3 and 1H-pyrrole-2,5-dicarboxylic acid in a reaction vessel, add sodium formate and water, mix and stir until homogeneous to obtain a reaction mixture;

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

[0008] Preferably, the concentration of aluminum trichloride 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 heating reaction in step (2) is a reflux reaction with oil bath heating to 100°C.

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

[0011] Preferably, the washing process in step (2) involves washing with DMF first, followed by washing with ethanol. More preferably, each detergent is used for three washes.

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

[0013] This invention also provides the application of micron-sized GM-1 material in the preparation of capillary chromatography columns. The method for preparing capillary chromatography columns includes the following steps:

[0014] (1) The above-mentioned hierarchical porous micron-sized GM-1 material was ultrasonically dispersed in an organic solvent to obtain a mixture;

[0015] (2) Use an injection pump to push the mixture into the pretreated capillary column at a constant speed and dynamically coat it onto the inner wall of the capillary column.

[0016] (3) The capillary column is aged under an inert atmosphere by programmed temperature increase and then cooled to room temperature to obtain the capillary gas chromatography column.

[0017] This 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 an atmosphere composed of one or more of nitrogen, helium or argon in any proportion.

[0020] Preferably, the specific method of the programmed temperature rise aging treatment in step (3) is as follows: 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] This invention also provides the application of micron-sized GM-1 material in the preparation of vapor-phase packed columns. The preparation method of the vapor-phase packed column includes the following steps:

[0022] (1) The above-mentioned multi-level porous micron-sized GM-1 material was degassed under high temperature vacuum.

[0023] (2) The degassed material is sieved through a sieve to obtain adsorbent particles of uniform size;

[0024] (3) Use a funnel to fill the granules into the stainless steel packed column and seal the ends;

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

[0026] The prepared gas-phase packed column is installed at the back end of the xylene isomer mixed vapor, which enables large-scale and efficient separation of xylene isomers.

[0027] Preferably, the inert atmosphere in step (4) is an atmosphere composed of one or more of nitrogen, helium or argon in any proportion.

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

[0029] Connect the capillary gas chromatography column to the gas chromatograph, and connect the stainless steel gas chromatograph packing column to the front end of the gas chromatograph and the back end of the xylene isomer mixed vapor. After setting the oven temperature and retention time, carrier gas flow rate and oil bath temperature of the packing column, use the flow controller to carry the target analyte into the packing column by the carrier gas. The tail gas enters the gas chromatograph. After clicking start test, the chromatographic peaks of the corresponding xylene isomers can be obtained after a few minutes.

[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 in this invention, as an adsorbent, achieves extremely high penetration separation of p-m-xylene and p-xylene in the packed column, with a meta / para separation degree as high as 4.5; as a stationary phase, it also achieves baseline separation of the three xylene isomers, with a meta / para separation degree as high as 21.9, and the prepared gas chromatography column and stainless steel packed column have extremely high stability and repeatability; (2) The micron-sized GM-1 material has p-m-xylene Second-order adsorption characteristics, with a record adsorption of 4.0 mmol / g for m-xylene at 30℃; (3) The material particles have a large specific surface area, which is conducive to the adsorption of target substances. The material size is suitable and uniform. It can be used as a stationary phase for gas chromatography columns or as a packing adsorbent for gas chromatography packed columns. It can be used to realize trace detection of xylene isomers as well as large-scale separation of xylene isomers. It has a wide range of applications and is a highly promising material for the detection and separation of xylene isomers. It is of great significance in the fields of industry and environmental science. Attached Figure Description

[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 The image shows the powder XRD pattern of the micron-sized GM-1 material in Example 2 of this invention.

[0033] Figure 3 This is a scanning electron microscope image of the chromatographic column coated with 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 in the micron-sized GM-1 material of Example 5 of the present invention;

[0035] Figure 5 The chromatograms are those of the micron-sized GM-1 stationary phase in Example 3 and the breakthrough separation diagram of the adsorbent-packed column in Example 6 of this invention.

[0036] Figure 6 The images show gas chromatograms obtained by separating xylene isomers using the capillary gas chromatography column prepared in Example 3 of this invention, and breakthrough separation chromatograms obtained by breaking through xylene isomers using the stainless steel gas chromatographic packed column prepared in Example 5; wherein... Figure 6 a. Breakthrough separation diagram obtained from the separation of p-xylene and m-xylene Figure 6 b. Breakthrough separation diagram obtained from the separation of m-xylene and o-xylene. Figure 6 c is the breakthrough separation diagram obtained from the separation of p-xylene and o-xylene. Figure 6d is the gas chromatogram obtained by gas chromatography separation of xylene isomers using the capillary column prepared in Example 3. Detailed Implementation

[0037] The technical solution of the present invention will be further described in detail below through specific embodiments. However, it should be noted that the following embodiments are only used to describe the content of the invention and do not constitute a limitation on the scope of protection of the present invention. The gas chromatograph used in the present invention is an Agilent GC7890B, and the reagents used are analytical grade or chromatographic grade.

[0038] Example 1

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

[0040] (1) In a 50 mL round-bottom flask, add 133 mg aluminum trichloride, 128 mg H2PyDC, 120 mg sodium formate and 15 mL water. Sonicate the mixture until it is clear and transparent. Heat it in an oil bath to 100 °C and keep it under reflux for 24 hours. Then stop the oil bath and cool the round-bottom flask to room temperature.

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

[0042] Figure 1 This is a scanning electron microscope image of the micron-sized GM-1 material. The image shows that the material has a width of several micrometers and a blocky shape.

[0043] Figure 5 The figure shows the single-component vapor adsorption diagram of m-xylene for micron-sized GM-1 material. It can be seen from the figure that micron-sized GM-1 exhibits second-order adsorption characteristics for m-xylene, with an adsorption capacity as high as 4.0 mmol / g.

[0044] Example 2

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

[0046] (3) In a 50 mL round-bottom flask, add 125 mg aluminum trichloride, 130 mg H2PyDC, 130 mg sodium formate and 18 mL water. Sonicate the mixture until it is clear and transparent. Heat it in an oil bath to 100 °C and keep it under reflux for 20 hours. Then stop the oil bath and cool the round-bottom flask to room temperature.

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

[0048] Figure 2 The image shows the powder XRD pattern of the micron-sized GM-1 material. It can be seen from the image 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] Application of micron-sized GM-1 material in the preparation of capillary chromatography columns. The preparation method of capillary chromatography columns includes the following steps:

[0051] (1) The above porous micron material was ultrasonically dispersed in methanol to obtain a mixture;

[0052] (2) Use an injection pump to push the mixture into the pretreated capillary column at a constant speed and dynamically coat it onto the inner wall of the capillary column.

[0053] (3) The capillary column was aged under a nitrogen inert atmosphere by programmed temperature increase. The specific parameters of the programmed temperature increase were: initial temperature 20 degrees Celsius, temperature increase to 250 degrees Celsius at a rate of 10 degrees Celsius / minute, hold for 8 hours, and then cool to room temperature to obtain the capillary gas chromatography column.

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

[0055] Example 4

[0056] Application of micron-sized GM-1 material in the preparation of capillary chromatography columns. The preparation method of capillary chromatography columns includes the following steps:

[0057] (1) The above-mentioned hierarchical porous micron-sized GM-1 material was ultrasonically dispersed in methanol to obtain a mixture;

[0058] (2) Use an injection pump to push the mixture into the pretreated capillary column at a constant speed and dynamically coat it onto the inner wall of the capillary column.

[0059] (3) The capillary column was aged under a helium inert atmosphere by programmed temperature increase. The specific parameters of the programmed temperature increase were: initial temperature 50 degrees Celsius, temperature increase to 250 degrees Celsius at a rate of 2 degrees Celsius / minute, hold for 2 hours, and then cool to room temperature to obtain the capillary gas chromatography column.

[0060] This 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] Application of micron-sized GM-1 material in the preparation of vapor-phase packed columns. The preparation method of vapor-phase packed columns includes the following steps:

[0063] (1) The above-mentioned multi-level porous micron-sized GM-1 material was degassed under high temperature vacuum.

[0064] (2) The degassed material is sieved through a sieve to obtain adsorbent particles of uniform size;

[0065] (3) Use a funnel to fill the granules into the stainless steel packed column and seal the ends;

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

[0067] The prepared gas-phase packed column is installed at the back end of the xylene isomer mixed vapor, which enables large-scale and efficient separation of xylene isomers.

[0068] Example 6

[0069] Application of micron-sized GM-1 material in the preparation of vapor-phase packed columns. The preparation method of vapor-phase packed columns includes the following steps:

[0070] (1) The above-mentioned multi-level porous micron-sized GM-1 material was degassed under high temperature vacuum.

[0071] (2) The degassed material is sieved through a sieve to obtain adsorbent particles of uniform size;

[0072] (3) Use a funnel to fill the granules into the stainless steel packed column and seal the ends;

[0073] (4) The stainless steel packed column is subjected to a programmed temperature aging treatment in an inert atmosphere composed of nitrogen and argon. The specific parameters of the programmed temperature are: initial temperature 50℃, temperature increased to 150℃ at a rate of 2℃ / min, held for 12h, and then cooled to room temperature to obtain the gas phase packed column.

[0074] The prepared gas-phase packed column is installed at the back end of the xylene isomer mixed vapor, which enables large-scale and efficient separation of xylene isomers.

[0075] Figure 5The figures show the chromatographic separation diagrams of the micron-sized GM-1 stationary phase in Example 3 and the breakthrough separation diagram of the stationary phase used as an adsorbent in Example 6. As can be seen from the figures, the micron-sized GM-1, as a gas chromatography stationary phase, produces narrow and sharp chromatographic peaks, enabling complete separation of xylene isomers. As an adsorbent, the micron-sized GM-1 produces a large breakthrough separation window, allowing for the efficient and large-scale separation of xylene isomers. This indicates that the micron-sized GM-1 material synthesized in this invention has promising application prospects in gas chromatography and breakthrough separation.

[0076] The micron-sized materials prepared in the above examples were physically characterized using methods such as SEM and single-component vapor adsorption. SEM analysis of porous micron-sized materials... Figure 1 It was learned that the material has uniform size, consisting of three-dimensional particles at the micrometer level. (SEM image of the column cross-section) Figure 3 This shows that hierarchical porous microparticles are uniformly 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, with a BET specific surface area of ​​1073.79 m². 2 / g, with strong adsorption capacity. Single-component vapor adsorption spectrum ( Figure 5 The results show that this micron-sized material has an extremely strong adsorption capacity for xylene isomers, and the material has a second-order adsorption characteristic for m-xylene isomers, with a large adsorption capacity. Figure 6 The images show gas chromatograms obtained from separating xylene mixtures using the capillary gas chromatography column prepared in Example 3, and breakthrough separation chromatograms obtained from breaking down xylene mixtures using the stainless steel packed gas chromatography column prepared in Example 5. The meta / para chromatographic resolution is as high as 21.9, and the meta / para breakthrough resolution is as high as 4.5. These results demonstrate that this material can be used for both trace detection and large-scale separation of xylene isomers, showing great promise for isomer separation.

[0077] In summary, this invention provides a method for preparing micron-sized GM-1 materials. This invention is the first to apply micron-sized GM-1 to gas chromatography and breakthrough separation. The micron-sized GM-1 particles are small and uniform in size, making them suitable as both capillary column stationary phases and stainless steel gas chromatography packed columns. The thermodynamic forces and diffusion rates of xylene isomers differ significantly in the micron-sized GM-1 stationary phase. Micron-sized GM-1 exhibits excellent separation performance in gas chromatography. The adsorption amounts of xylene isomers vary considerably in the micron-sized GM-1 adsorbent, thus demonstrating excellent breakthrough separation performance. This invention uses a solvothermal synthesis method with simple equipment, which can be applied to the synthesis of other micron-sized MOFs. The resulting material has small size and uniform morphology, making it a highly promising gas chromatography stationary phase.

Claims

1. A method for preparing micron-sized GM-1 material, characterized in that, Includes the following steps: (1) Place AlCl3 and 1H-pyrrole-2,5-dicarboxylic acid in a reaction vessel, add sodium formate and water, mix and stir until homogeneous to obtain the reaction mixture; (2) The reaction mixture in step (1) is heated and reacted for 20-30 hours to obtain white micron material. After cooling to room temperature, it is filtered, washed and dried to obtain multi-level porous micron-scale GM-1 material. The concentration of aluminum trichloride 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. The heating reaction described in step (2) is to heat the oil bath to 100°C. o C condensation and reflux reaction; The washing process described in step (2) is to first wash with DMF and then with ethanol, and each detergent is used to wash three times. The drying process described in step (2) is to allow the product to evaporate naturally at room temperature.

2. The application of the micron-sized GM-1 material prepared by the method according to claim 1 in the preparation of capillary chromatography columns, characterized in that, The preparation of capillary chromatography columns includes the following steps: (1) The multi-level porous micron-sized GM-1 material was ultrasonically dispersed in methanol to obtain a mixture; (2) Use an injection pump to push the mixture into the pretreated capillary column at a constant speed and dynamically coat it onto the inner wall of the capillary column. (3) The capillary column is aged under an inert atmosphere by programmed temperature increase and cooled to room temperature to obtain the capillary gas chromatography column.

3. The application of the micron-sized GM-1 material according to claim 2 in the preparation of capillary chromatography columns, characterized in that, The inert atmosphere mentioned in step (3) is an atmosphere composed of one or more of nitrogen, helium or argon in any proportion.

4. The application of the micron-sized GM-1 material according to claim 2 in the preparation of capillary chromatography columns, characterized in that, The specific method of the programmed temperature aging treatment in step (3) is as follows: 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.

5. The application of the micron-sized GM-1 material prepared by the method according to claim 1 in the preparation of vapor-phase packed columns, characterized in that, The preparation of a vapor-phase packed column includes the following steps: (1) High-temperature vacuum degassing of multi-level porous micron-sized GM-1 material; (2) The degassed material is sieved through a sieve to obtain adsorbent particles of uniform size; (3) Fill the stainless steel packed column with the granules using a funnel and seal the ends; (4) The stainless steel packed column is subjected to a programmed temperature aging treatment in an inert atmosphere, and then cooled to room temperature to obtain the gas phase packed column.

6. The application of the micron-sized GM-1 material according to claim 5 in the preparation of vapor-phase packed columns, characterized in that, The specific method of the programmed temperature aging treatment in step (4) is as follows: the initial temperature is 20-50 ℃, and the temperature is increased to 150 ℃ at a rate of 2°C / min ~ 10 °C / min, and held for 12-18 h.

Images