A hydrogen-bonded organic framework UPC-HOF-6 derived carbon molecular sieve membrane for gas separation, its preparation method and its application

Abstract

This invention relates to a hydrogen-bonded organic framework (UPC-HOF-6) derived carbon molecular sieve membrane for gas separation, its preparation method, and its application, belonging to the field of gas separation technology. The invention first prepares the UPC-HOF-6 monomer NBP-DAT, then prepares a UPC-HOF-6 precursor membrane, and finally prepares a hydrogen-bonded organic framework (UPC-HOF-6) derived carbon molecular sieve membrane at different carbonization temperatures. This carbon molecular sieve membrane can be applied in carbon dioxide / methane separation. Compared with the UPC-HOF-6 precursor membrane, the carbon molecular sieve membrane prepared by this invention has a narrower pore size distribution, enhanced gas sieving capacity, and significantly improved gas separation performance. The method of this invention is simple, effectively reduces the use of organic reagents, reduces pollution, is easier to prepare on a large scale, and provides a new approach to the selection of carbon molecular sieve membrane precursors.

Description

Technical Field

[0001] This invention belongs to the field of gas separation technology, specifically relating to a hydrogen-bonded organic framework UPC-HOF-6 derived carbon molecular sieve membrane for gas separation, its preparation method, and its application in carbon dioxide / methane separation. Background Technology

[0002] Natural gas is widely recognized as a high-quality, high-efficiency energy source due to its versatility, availability, and high calorific value. However, natural gas produced from oil and gas fields is a mixture containing methane (CH4) and residues such as carbon dioxide (CO2), water, and hydrogen sulfide. These impurities must be removed because they corrode and damage oil pipelines and affect the calorific value. Traditional carbon dioxide removal technologies include amine absorption, cryogenic separation, and membrane separation. Currently, the most advanced and accurate method for carbon dioxide removal is amine absorption, but it suffers from high equipment investment, high energy consumption, and environmental pollution. Membrane separation technology is considered one of the emerging separation technologies of this century because of its good energy efficiency, flexibility, and small footprint. Various types of membrane materials, including polymer membranes, inorganic-based membranes such as zeolites, metal-organic frameworks, and carbon molecular sieve (CMS) membranes, have been developed for the efficient removal of carbon dioxide from natural gas. Among all these known membranes, polymer membranes have received the most attention due to their excellent performance in natural gas separation. However, the trade-off between permeability and selectivity, as well as the plasticizing and aging behavior of polymer membranes, limits their application in CO2 / CH4 separation. Although zeolite and metal-organic framework membranes have shown superior performance compared to polymer membranes, their industrial application is significantly hindered by high cost and complex manufacturing processes. Therefore, developing membranes with efficient and achievable CO2 / CH4 separation performance is crucial.

[0003] CMS membranes are high-performance carbon-based porous membranes, typically prepared from pyrolytic polymer precursors. Due to the unique combination of highly permeable micropores and molecular sieve ultrapores, CMS membranes exhibit excellent gas permeability and separation selectivity. Choosing a suitable precursor is considered a key factor in constructing high-performance CMS membranes. The first CMS membrane was prepared by Koresh and Soffer (Sep. Sci. Technol. 18, 723-734) in 1983 using a pyrolytic polymer precursor. Since then, extensive research has been conducted on CMS membranes to reveal the influence of polymer precursors on the final CMS membrane. Currently, the most commonly used precursors are thermosetting polymers, which do not melt during heat treatment and maintain the membrane morphology and pore structure, such as polyimides, polyfurfural, phenolic resins, cellulose derivatives, and polymers with inherent micropores (PIMs).

[0004] Polyimides, typically composed of dianhydrides and diamines, are among the most studied precursor materials, exhibiting a wide variety of molecular structures. Koros et al. (J.Membr.Sci.487,60-73) prepared a series of highly permeable CMSs using polyimides containing 6 FDA units. Centeno et al. (J.Membr.Sci.160,201-211) investigated phenolic resin-based CMS membranes coated on ceramic tubular supports, demonstrating excellent separation capabilities for CO2 / CH4 and CO2 / N2. Pinnau et al. (J.Membr.Sci.504,133-140) studied the gas separation performance of CMS membranes derived from trapezoidal PIMs such as PIM-1, demonstrating that the inherent microporosity of the polymer precursor significantly influences the derivation of the final microporous structure of the CMS membrane. These studies indicate that the development of CMS membranes with high gas permeability and selectivity will benefit from precursors exhibiting high thermal stability, carbon residue, and porosity with favorable film-forming properties.

[0005] Besides polymer precursors, exploring other microporous precursors is crucial for the preparation of high-performance CMS membranes. Hydrogen-bonded organic frameworks (HOFs) are a unique class of crystalline porous materials, typically self-assembled from organic units through intermolecular hydrogen bonding. In addition to possessing an ordered and designable pore structure like other crystalline porous materials, HOFs also exhibit polymer solubility, making their conversion into membranes straightforward. HOFs with ordered pores hold great promise for conversion into CMS membranes with narrow pore distributions. However, research using HOFs as precursors to prepare CMS membranes has not yet been reported.

[0006] Based on the above, this invention utilizes a UPC-HOF-6 polycrystalline film (Angew. Chem. Int. Ed. 59, 3840-3845), which can be prepared by solution processing of polymer films, as a precursor film to prepare CMS, while avoiding the additional complex modification process required to prepare highly selective CMS films. The HCMS film prepared by high-temperature carbonization of UPC-HOF-6 exhibits improved selectivity compared to the untreated UPC-HOF-6 precursor film material. Summary of the Invention

[0007] To address the problems existing in the prior art, this invention provides a hydrogen-bonded organic framework UPC-HOF-6 derived carbon molecular sieve membrane (HCMS) for gas separation, a high-temperature carbonization preparation method, and its application in carbon dioxide / methane separation. Compared with the UPC-HOF-6 precursor membrane, the HCMS membrane prepared by this invention has a narrower pore size distribution, enhanced gas sieving capacity, and significantly improved gas separation performance.

[0008] This invention employs a high-temperature carbonization method to process the precursor UPC-HOF-6 polycrystalline membrane material prepared by conventional methods, thereby obtaining a defect-free carbon molecular sieve membrane material. The preparation steps are as follows:

[0009] (1) Preparation of UPC-HOF-6 monomer NBP-DAT:

[0010] Under a nitrogen atmosphere, 4-cyanobenzoic acid, tris(4-bromophenyl)amine, and anhydrous N,N-dimethylformamide (DMF) were stirred and mixed thoroughly. Deionized water and K₂CO₃ solution were then added and stirred until homogeneous. Tetra(triphenylphosphine)palladium was then added and stirred until homogeneous. The molar ratio of 4-cyanobenzoic acid, tris(4-bromophenyl)amine, DMF, deionized water, K₂CO₃, and tetra(triphenylphosphine)palladium was 52.5:12.5:2689:3950:71.1:1. The reaction system was then heated to... The mixture was stirred at 85–95 °C under a nitrogen atmosphere for 40–60 hours. After the reaction was completed, it was cooled to room temperature, and the mixture was dissolved in dichloromethane and filtered to remove impurities. The organic phase was then extracted with deionized water 3–5 times, and the volatiles were removed by rotary evaporation to obtain the crude product. The crude product was dried at 80–100 °C for 10–12 hours, and then purified by silica gel column chromatography with dichloromethane as the eluent to obtain a pale yellow product, namely 4,4',4”-iminetris([1,1'-biphenyl]-4-cyano), with a yield of 70–80%.

[0011] 4,4',4”-iminetris([1,1'-biphenyl]-4-cyano), dicyandiamide, ethylene glycol methyl ether, and KOH were mixed in a molar ratio of 1:6.7:572:1.7 and stirred at room temperature for 30–60 minutes under a nitrogen atmosphere. The reaction temperature was then raised to 120–130 °C and reacted for 25–30 hours. After the reaction was completed, the mixture was cooled to room temperature and filtered. The filtered product was then dried at 80–100 °C for 20–30 hours to obtain a yellow product, namely 4,4,4-tris(2,4-diamino-1,3,5-triazinylphenyl)aniline (NBP-DAT), with a yield of 75–80%.

[0012] (2) Preparation of UPC-HOF-6 precursor membrane

[0013] The NBP-DAT prepared in step (1) was added to dimethyl sulfoxide (DMSO) and heated at 150–160 °C for 10–15 minutes to dissolve it, preparing a solution with a concentration of 100–150 mg / mL. -1The mother liquor was then cooled to room temperature. 100 μL of the mother liquor was then spin-coated onto a circular porous Al2O3 substrate (15–20 mm in diameter, 1 mm thick, purchased from Yirun Jingtao New Materials Co., Ltd.) at a speed of 800–1200 r / s for 20–40 seconds. Immediately afterwards, it was heated at 80–90 °C for 10–15 minutes to evaporate the solvent, causing UPC-HOF-6 crystals to precipitate and form a thin film. By repeating the above "spin-coating-heating" process 8–12 times, a UPC-HOF-6 precursor film was obtained.

[0014] (3) Preparation of HCMS membrane

[0015] The UPC-HOF-6 precursor membrane obtained in step (2) was subjected to programmed temperature rise under a nitrogen atmosphere, i.e., first at 1-2 °C / min. -1 The heating rate is increased to 280–320℃ and held for 1.5–3.0 hours, then increased by 1–2℃ per minute. -1 The temperature is increased to 550–650°C and maintained for 2–4 hours, then decreased by 1–2°C per minute. -1 The membranes were cooled to room temperature at a decreasing rate to obtain hydrogen-bonded organic framework UPC-HOF-6 derived carbon molecular sieve membranes (HCMS) with different final carbonization temperatures as described in this invention for gas separation. The membranes were stored in a constant temperature and humidity chamber before gas permeability testing.

[0016] The HCMS membrane material described in this invention can be used for gas separation, especially for the separation of carbon dioxide and methane. Single-component gas permeation experiments were conducted using the Wicke-Kallenbach permeation technique, with argon as the purge gas at a flow rate of 100 mL / min. The components of the permeated gas were analyzed using a gas chromatograph (SHIMADZUGC-2014C).

[0017] The beneficial effects of this invention are as follows:

[0018] This invention utilizes a high-temperature carbonization method to carbonize a hydrogen-bonded organic framework (UPC-HOF-6) membrane prepared by solvent evaporation into a carbon molecular sieve membrane. The narrowed pore size distribution of the membrane improves gas separation performance. This method is simple, effectively reduces the use of organic reagents, minimizes pollution, facilitates large-scale preparation, and provides a new approach to the selection of preconditions for carbon molecular sieve membranes.

[0019] The relevant test conditions and methods involved in this invention are as follows:

[0020] Scanning electron microscopy (SEM) testing: The morphology of the membrane samples prepared in Examples 1-3 and Comparative Example 1 was characterized using a Hitachi Regulus 8100 field emission scanning electron microscope.

[0021] X-ray electron diffraction (XRD) test: The film materials obtained in Examples 1-3 and Comparative Example 1 were characterized using a Rigaku MiniFlex 600 X-ray diffractometer (Japan). Cu emission field was used, and the scanning 2θ range was 5-50°.

[0022] Pore ​​size distribution test: The test was conducted using an Autosorb-iQ fully automated gas adsorption analyzer from the American company Quanta at 273 K with CO2.

[0023] The gas separation test was performed using the Wicke-Kallenbach Technique apparatus (Angew. Chem. Int. Ed. 2006, 45, 7053-7056). The flow rates of carbon dioxide, methane, and carrier gas Ar were controlled by a mass flow controller. The feed gas permeating the membrane was purged by the carrier gas and entered the gas chromatograph. The content of different gases was measured to finally determine the separation effect.

[0024] Gas chromatography (GC) analysis: Shimadzu GC2014; column temperature: 50℃; detector: TCD; the gas mixture consisted of carbon dioxide and methane in a 1:1 volume ratio. Attached Figure Description

[0025] Figure 1 XRD patterns of the UPC-HOF-6 precursor membranes prepared in Examples 1-3 and Comparative Example 1;

[0026] like Figure 1 As shown in the figure, by comparing the simulated XRD diffraction pattern (UPC-HOF-6 simulation), it can be seen that the present invention successfully obtained a polycrystalline film with a UPC-HOF-6 structure through solvent evaporation.

[0027] Figure 2 XRD diffraction patterns of HCMS film materials prepared at different carbonization temperatures in Examples 1-3;

[0028] like Figure 2 As shown, to compare the effects of carbonization temperature on the gas permeability and selectivity of HCMS membranes, this invention prepared carbon molecular sieve membranes carbonized at different temperatures. XRD diffraction patterns indicate that high-temperature carbonization transformed HOF into an amorphous carbon structure, successfully preparing the carbon molecular sieve membrane material.

[0029] Figure 3 Pore ​​size distribution diagrams of HCMS membrane materials prepared at different carbonization temperatures in Examples 1-3;

[0030] like Figure 3 As shown, the HCMS membrane prepared by this invention has a narrower pore size distribution, which is beneficial for gas sieving.

[0031] Figure 4 SEM images of HCMS membrane materials prepared at different carbonization temperatures in Examples 1-3;

[0032] like Figure 4 As shown, this invention has produced a continuous carbon molecular sieve membrane material without obvious defects. Detailed Implementation

[0033] Example 1:

[0034] (1) Preparation of UPC-HOF-6 monomer NBP-DAT:

[0035] The reaction was carried out entirely under a nitrogen atmosphere. 70.9 mmol of 4-cyanobenzoic acid, 16.9 mmol of tris(4-bromophenyl)amine, and 300 mL of anhydrous N,N-dimethylformamide (DMF) were mixed and stirred for 30 minutes in a 500 mL three-necked flask. Then, 48 mL of deionized water and 48 mL of 2 mol / L... -1 A K₂CO₃ solution was added to a flask and stirred for 30 minutes. Then, 1.35 mmol of tetrakis(triphenylphosphine)palladium was added to the reaction system and stirred for another 30 minutes. Finally, the reaction system was heated to 90 °C and stirred continuously under a nitrogen atmosphere for 48 hours. After the reaction was complete, the mixture was cooled to room temperature, dissolved in dichloromethane, and filtered to remove impurities. The organic phase was then extracted three times with deionized water, and volatiles were removed by rotary evaporation. The crude product was dried at 80 °C for 10 hours and then purified by silica gel column chromatography using dichloromethane as the eluent, finally yielding a pale yellow product, 4,4',4”-iminetris([1,1'-biphenyl]-4-cyano), in 75% yield.

[0036] 3.2 mmol of 4,4',4”-iminetris([1,1'-biphenyl]-4-cyano), 21.4 mmol of dicyandiamide, and 150 mL of ethylene glycol methyl ether were mixed in a 500 mL three-necked flask at room temperature. After stirring under a nitrogen atmosphere for 30 minutes, 5.4 mmol of KOH was added to the reaction solution, and the mixture was stirred for another 30 minutes. The reaction temperature was then raised to 125 °C and reacted for 24 hours. After the reaction was completed and cooled to room temperature, the mixture was filtered, and the filtered product was dried at 80 °C for 24 hours to give the yellow product 4,4,4-tris(2,4-diamino-1,3,5-triazinylphenyl)aniline (NBP-DAT) in 78% yield.

[0037] (2) Preparation of UPC-HOF-6 precursor membrane

[0038] Accurately weigh 120 mg of the monomer NPB-DAT prepared in step (1) and dissolve it in 1 mL of DMSO. After heating at 150 °C for 15 minutes, a concentration of 120 mg / mL is obtained. -1The UPC-HOF-6 mother liquor was used. After cooling to room temperature, 100 μL of the mother liquor was sprayed onto a circular porous Al2O3 substrate (substrate area 2.5434 cm²) at a speed of 1000 r / s. 2 Spin-coating for 30 seconds, then immediately transferring to an 80°C oven and heating for 15 minutes to evaporate the solvent, causing UPC-HOF-6 crystals to precipitate and form a thin film. By repeating the above "spin-coating-heating" process 10 times, a UPC-HOF-6 precursor film with a thickness of 16.4 μm was obtained.

[0039] (3) Preparation of HCMS membrane

[0040] The UPC-HOF-6 precursor membrane obtained in step (2) was placed in a tube furnace and subjected to programmed temperature rise under a nitrogen atmosphere. Initially, the temperature was increased at 1°C / min. -1 The heating rate was increased to 300℃ and held for 2 hours, then increased at 1℃ / min. -1 The temperature was increased to 550℃ and held for 3 hours, then increased at a rate of 1℃ / min. -1 The HCMS membrane was prepared by cooling to room temperature at a cooling rate of M1.

[0041] (4) Characterization of membranes

[0042] The UPC-HOF-6 precursor membrane was subjected to XRD analysis, and the prepared membrane was characterized by SEM, pore size distribution testing, and CO2 / CH4 separation performance testing. The separation performance results are shown in Table 1.

[0043] Table 1: CO2 / CH4 gas flux and CO2 / CH4 separation factor at 25℃ and 1.4 bar.

[0044]

[0045]

[0046] Flux is the volume of gas permeating per unit time per unit membrane area, expressed in P (unit: GPU: 3.35*10). -10 mol m -2 s - 1 Pa -1 To represent, N i (mol s -1 Let ΔP be the permeation rate of the permeating gas i. i (Pa) represents the transmembrane pressure difference of the permeating gas i, A(m 2 The effective membrane area is represented by the separation factor. The separation performance of a membrane is reflected in its separation factor. Example 2:

[0047] (1) Prepare UPC-HOF-6 monomer NBP-DAT according to step (1) of Example 1.

[0048] (2) Prepare UPC-HOF-6 precursor membrane according to step (2) of Example 1.

[0049] (3) Preparation of HCMS membrane

[0050] The UPC-HOF-6 precursor membrane obtained in step (2) was placed in a tube furnace and subjected to programmed temperature rise under a nitrogen atmosphere. Initially, the temperature was increased at 1°C / min. -1 The heating rate was increased to 300℃ and held for 2 hours, then increased at 1℃ / min. -1 The temperature was increased to 600℃ and held for 3 hours, then increased at a rate of 1℃ / min. -1 The HCMS membrane was prepared by cooling to room temperature at a cooling rate of M2.

[0051] (4) Characterization of membranes

[0052] The UPC-HOF-6 precursor membrane was subjected to XRD analysis, and the prepared membrane was characterized by SEM, pore size distribution testing, and CO2 / CH4 separation performance testing. The separation performance results are shown in Table 2.

[0053] The separation performance test results are shown in Table 2.

[0054] Table 2: CO2 / CH4 gas flux and CO2 / CH4 separation factor at 25℃ and 1.4 bar.

[0055] ID <![CDATA[CO2(GPU)]]> <![CDATA[CH4(GPU)]]> <![CDATA[CO2 / CH4 separation factor]]> M2 47.64 0.37 128.76

[0056] Flux is the volume of gas permeating per unit time per unit membrane area, expressed in P (unit: GPU: 3.35*10). -10 mol m -2 s - 1 Pa -1 To represent, N i (mol s -1 Let ΔP be the permeation rate of the permeating gas i. i (Pa) represents the transmembrane pressure difference of the permeating gas i, A(m 2 The effective membrane area is represented by the separation factor. The separation performance of a membrane is reflected in its separation factor. Example 3:

[0057] (1) Prepare UPC-HOF-6 monomer NBP-DAT according to step (1) of Example 1.

[0058] (2) Prepare UPC-HOF-6 precursor membrane according to step (2) of Example 1.

[0059] (3) Preparation of HCMS membrane

[0060] The UPC-HOF-6 precursor membrane obtained in step (2) was placed in a tube furnace and subjected to programmed temperature rise under a nitrogen atmosphere. Initially, the temperature was increased at 1°C / min. -1 The heating rate was increased to 300℃ and held for 2 hours, then increased at 1℃ / min. -1 The temperature was increased to 650℃ and held for 3 hours, then increased at a rate of 1℃ / min. -1 The HCMS membrane was prepared by cooling to room temperature at a cooling rate of M3.

[0061] (4) Characterization of membranes

[0062] The UPC-HOF-6 precursor membrane was subjected to XRD analysis, and the prepared membrane was characterized by SEM, pore size distribution testing, and CO2 / CH4 separation performance testing. The separation performance results are shown in Table 3.

[0063] Table 3: CO2 / CH4 gas flux and CO2 / CH4 separation factor at 25℃ and 1.4 bar.

[0064] ID <![CDATA[CO2(GPU)]]> <![CDATA[CH4(GPU)]]> <![CDATA[CO2 / CH4 separation factor]]> M3 41.31 0.36 114.75

[0065] Flux is the volume of gas permeating per unit time per unit membrane area, expressed in P (unit: GPU: 3.35*10). -10 mol m -2 s - 1 Pa -1 To represent, N i (mol s -1 Let ΔP be the permeation rate of the permeating gas i. i (Pa) represents the transmembrane pressure difference of the permeating gas i, A(m 2 The effective membrane area is represented by the separation factor. The separation performance of a membrane is reflected in its separation factor. Comparative Example 1:

[0066] (1) Prepare UPC-HOF-6 monomer NBP-DAT according to step (1) of Example 1.

[0067] (2) Prepare the UPC-HOF-6 precursor membrane according to step (2) of Example 1, and designate it as M4.

[0068] (3) Characterization of membranes

[0069] The prepared M4 was subjected to XRD tests and CO2 / CH4 separation performance tests. The separation performance results are shown in Table 4.

[0070] Table 4: CO2 / CH4 gas flux and CO2 / CH4 separation factor at 25℃ and 1.4 bar.

[0071]

[0072] Flux is the volume of gas permeating per unit time per unit membrane area, expressed in P (unit: GPU: 3.35*10). -10 mol m -2 s - 1 Pa -1 To represent, N i (mol s -1 Let ΔP be the permeation rate of the permeating gas i. i (Pa) represents the transmembrane pressure difference of the permeating gas i, A(m 2 The effective membrane area is represented by the separation factor. The separation performance of a membrane is reflected in its separation factor.

[0073] Comparing the carbon dioxide / methane separation performance data of HCMS membrane and UPC-HOF-6 membrane in Example 2 and Comparative Example 1, the results show that using UPC-HOF-6 as a precursor membrane material for carbon molecular sieves does indeed significantly improve the gas separation performance of the membrane.

Claims

1. A method for preparing a hydrogen-bonded organic framework UPC-HOF-6 derived carbon molecular sieve membrane for gas separation, the preparation steps of which are as follows: (1) Preparation of UPC-HOF-6 monomer NBP-DAT: Under a nitrogen atmosphere, 4-cyanobenzoic acid, tris (4-bromophenyl) amine and anhydrous N, N-dimethylformamide are stirred and mixed uniformly, deionized water and a K2CO3 solution are added and stirred and mixed uniformly, and then tetrakis (triphenylphosphine) palladium is added and stirred and mixed uniformly;Then, the reaction system is heated to 85-95℃ and stirred and reacted under a nitrogen atmosphere for 40-60 hours;After the reaction is completed, it is cooled to room temperature, the mixture is dissolved in dichloromethane to remove impurities by filtration, and then the organic phase is extracted with deionized water 3-5 times, and volatile matter is removed by rotary evaporation to obtain a crude product;The obtained crude product is dried at 80-100℃ for 10-12 hours, and then purified by silica gel column chromatography with dichloromethane as the eluent to obtain a light yellow product, i.e. 4, 4', 4"-iminotris ([1, 1'-biphenyl]-4-cyanide); 4, 4', 4"-iminotris ([1, 1'-biphenyl]-4-cyanide), dicyandiamide, ethylene glycol methyl ether and KOH are mixed at room temperature and stirred for 30-60 minutes under a nitrogen atmosphere, and then the reaction temperature is raised to 120-130℃ and reacted for 25-30 hours;After the reaction is completed and cooled to room temperature, it is filtered, and the filtered product is dried at 80-100℃ for 20-30 hours to obtain a yellow product, i.e. 4, 4, 4-tris (2, 4-diamino-1, 3, 5-triazinylphenyl) aniline, i.e. UPC-HOF-6 monomer NBP-DAT; (2) Preparation of UPC-HOF-6 precursor membrane The NBP-DAT prepared in step (1) was added to dimethyl sulfoxide and dissolved by heating at 150-160 °C for 10-15 minutes to prepare a UPC-HOF-6 mother liquor with a concentration of 100-150 mg / mL -1 The UPC-HOF-6 mother liquor was then cooled to room temperature and spin-coated on a circular porous Al2O3 substrate at a rotation speed of 800-1200 r / s for 20-40 seconds, and then heated at 80-90 °C for 10-15 minutes to evaporate the solvent and form a UPC-HOF-6 crystal film. The above "spin-coating-heating" process was repeated 8-12 times to obtain a UPC-HOF-6 precursor film. (3) Preparation of HCMS membrane The UPC-HOF-6 precursor membrane obtained in step (2) is subjected to temperature programmed under nitrogen atmosphere, i.e. first increasing to 280-320°C at a rate of 1-2°C / min -1 and keeping for 1.5-3.0 hours, then increasing to 550-650°C at a rate of 1-2°C / min -1 and keeping for 2-4 hours, and finally cooling to room temperature at a rate of 1-2°C / min -1 , thereby obtaining the hydrogen-bonded organic framework UPC-HOF-6 derived carbon molecular sieve membrane for gas separation.

2. A process for the preparation of hydrogen bonded organic framework, UPC-HOF-6 derived carbon molecular sieve membrane for gas separation as claimed in claim 1, wherein: In step (1), the molar ratio of 4-cyanobenzoic acid, tris (4-bromophenyl) amine, N, N-dimethylformamide, deionized water, K2CO3, tetrakis (triphenylphosphine) palladium is 52.5:12.5:2689:3950:71.1:1;The molar ratio of 4, 4', 4"-iminotris ([1, 1'-biphenyl]-4-cyanide), dicyandiamide, ethylene glycol methyl ether and KOH is 1:6.7:572:1.

7.

3. A hydrogen bonded organic framework, UPC-HOF-6 derived carbon molecular sieve membrane for gas separation, characterized by: is prepared by the method of claim 1 or 2.

4. The hydrogen-bonded organic framework UPC-HOF-6 derived carbon molecular sieve membrane for gas separation of claim 3 is used in carbon dioxide / methane separation.

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