A cu(i)-mof hybrid matrix membrane, a preparation method, and a photocatalysis-separation integrated device using the same and applications

Abstract

The application belongs to the field of membrane catalysis and separation technology, and particularly relates to a Cu(I)-MOF mixed matrix membrane, a preparation method, a photocatalysis-separation integrated device using the same and application. The mixed matrix membrane is prepared by mixing Cu(I)-MOF and a PEGBEM-POEM copolymer solution according to a specific mass ratio to obtain a casting solution, and then performing blade casting and drying; wherein the Cu(I)-MOF is synthesized from Hdmtz, Hdetz and copper oxide nanoparticles. The integrated device comprises a reactor shell provided with multiple parallel baffle assemblies, the mixed matrix membrane is fixed in the baffle assemblies, the internal space is divided into reaction-separation units in series, and a light source is arranged. After humid CO2 is introduced into the device, a photocatalytic reduction reaction occurs on the surface of the membrane under light to generate CO, and the high selectivity of the membrane to CO is used to realize in-situ separation and multi-stage purification of CO and O2. The application realizes efficient conversion and separation of CO2 into high-purity CO.

Description

Technical Field

[0001] This invention belongs to the field of membrane catalysis and separation technology, specifically relating to a Cu(I)-MOF mixed matrix membrane, its preparation method, and an integrated photocatalytic-separation device and application using it. Background Technology

[0002] The photocatalytic reduction of CO2 to CO produces a mixture of CO and O2 gases. Due to the high similarity in their physicochemical properties, traditional separation techniques struggle to achieve efficient separation, resulting in low product purity, high subsequent purification costs, and the strong oxidizing properties of O2 easily causing catalyst deactivation. This severely restricts the practical application and economic feasibility of this technology. To obtain high-purity CO, existing O2 and CO separation methods either face challenges such as high energy consumption and large investment (e.g., cryogenic separation), environmental pollution and equipment corrosion risks (e.g., chemical absorption), or limitations imposed by adsorbent / membrane material performance bottlenecks and process complexity (e.g., pressure swing adsorption and membrane separation). Therefore, there is an urgent need to develop a novel oxygen and CO separation technology that is highly efficient, low-energy, easy to operate, environmentally friendly, and applicable to a wide concentration range to overcome the shortcomings of existing technologies.

[0003] Combining photocatalytic CO2 reduction to CO with high-efficiency membrane separation of CO / O2, this integrated reaction-separation system achieves synergistic enhancement from feedstock conversion to product purification. This integrated strategy enables simultaneous photo-driven CO2 conversion and highly selective CO enrichment under mild conditions, significantly improving the purity and yield of the target product. Furthermore, in-situ separation effectively suppresses the risk of catalyst deactivation by the byproduct O2, ensuring the long-term operational stability and overall energy efficiency of the reaction system. This technological approach overcomes the inherent bottlenecks of complex processes and high energy consumption in traditional stepwise processes, providing a promising solution for the continuous, low-energy, and high-value utilization of carbon resources.

[0004] Metal-organic frameworks (MOFs) exhibit unique advantages in structural designability and functional integration in photocatalysis, providing an ideal molecular platform for efficient photogenerated charge separation, broad-spectrum absorption, and precise construction of catalytic active sites. Through precise control of framework composition and pore environment, the selectivity and efficiency of photocatalytic processes can be optimized, providing a key material foundation for innovative pathway design of a series of photodriven reactions. Simultaneously, as a novel type of highly designable porous material, MOFs demonstrate unique comprehensive advantages in gas separation. Through precise pore engineering and functional modification, they can achieve high-capacity and high-selectivity adsorption of specific gas molecules, breaking through the inherent balance limitations between separation performance and stability inherent in traditional porous materials. Introducing MOFs into a highly efficient separation and photocatalytic conversion system for CO and O2 achieves integrated enhancement of the selective adsorption of CO and the photodriven conversion process. This strategy utilizes the tunable pore structure and unsaturated metal sites of MOFs to efficiently capture CO while suppressing competitive adsorption of O2, and then directionally converts the enriched CO into high-value-added products through in-situ photocatalysis, thereby constructing a synergistic pathway integrating adsorption and conversion.

[0005] Based on the above design strategy, this invention designed and synthesized a Cu(I)-MOF hybrid matrix membrane, and successfully installed it in a photocatalytic separation system, realizing the photocatalytic generation of CO from CO and its efficient separation from O2. Summary of the Invention

[0006] The first objective of this invention is to provide a method for preparing a Cu(I)-MOF hybrid matrix membrane, comprising the following steps:

[0007] (1) 3,5-dimethyl-1,2,4-triazole (Hdmtz) and 3,5-diethyl-1,2,4-triazole (Hdetz) were dissolved in ethanol, copper oxide nanoparticles dispersed in ethanol were added, and the mixture was refluxed for 3 days under the condition of passing N2 to obtain Cu(I)-MOF;

[0008] (2) Methyl methacrylate and poly(ethylene glycol) dodecyl ether methacrylate (PEGBEM) were mixed at a mass ratio of 7:3 and dissolved in ethyl acetate containing azobisisobutyronitrile (AIBN). After being purged with N2, the mixture was reacted at 70 °C for 24 hours to obtain a polymer solution. Subsequently, excess hexane was added to precipitate the homogeneous solution. This precipitation process was repeated to remove byproducts. The product was completely dried overnight in a vacuum oven at room temperature to obtain the PEGBEM-POEM copolymer.

[0009] (3) Mix the PEGBEM-POEM copolymer obtained in step (2) with water and stir for 12 hours to obtain a PEGBEM-POEM copolymer solution.

[0010] (4) Mix the Cu(I)-MOF obtained in step (1) with the PEGBEM-POEM copolymer solution obtained in step (3) and stir to obtain a casting solution;

[0011] (5) Using a 200 μm scraper, the casting solution was uniformly scraped onto a glass plate with the PAN substrate film attached. Then, it was dried in a constant temperature and humidity chamber at 30℃ and 40 RH for 24 h to finally obtain the Cu(I)-MOF mixed matrix film.

[0012] Furthermore, in step (1), the molar ratio of Hdmtz to Hdetz is 3:2; the total amount of Hdmtz and Hdetz and the molar ratio of copper oxide nanoparticles are 4:1.

[0013] Furthermore, in step (2), the mass ratio of methyl methacrylate to poly(ethylene glycol) dodecyl ether methacrylate (PEGBEM) is 7:3, and the mass ratio of azobisisobutyronitrile to the total amount of monomers is 0.01:10.

[0014] Furthermore, in step (3), the mass concentration of the PEGBEM-POEM copolymer solution is 5%.

[0015] Furthermore, in step (4), the mass ratio of Cu(I)-MOF to PEGBEM-POEM copolymer is 3:7.

[0016] The present invention also provides a Cu(I)-MOF mixed matrix membrane prepared by the preparation method described above.

[0017] The present invention also provides the application of the Cu(I)-MOF hybrid matrix membrane in the photocatalytic generation of CO from CO2 and its efficient separation from O2.

[0018] This invention also provides an integrated photocatalysis-separation device, comprising a reactor shell. One side of the reactor shell has an inlet for introducing CO2 feed gas, and the other side has an outlet for discharging the separated and purified high-purity CO product. The shell contains multiple parallel baffle assemblies, each containing a Cu(I)-MOF mixed matrix membrane. The baffle assemblies are evenly spaced and parallel to the inner wall of the shell, dividing the internal space into multiple continuous, series-connected small chambers, which constitute continuous reaction-separation units. Between adjacent baffle assemblies, on the front side of the first baffle assembly, and on the rear side of the last baffle assembly, and between the front and rear sidewalls of the device, vertically arranged lamps are installed to simulate solar xenon lamps or LEDs of specific wavelengths. The sidewalls of the device also have a vacuum port for connecting a vacuum pump to evacuate the device before the reaction.

[0019] Furthermore, the partition assembly includes an outer frame, a sealing ring, a pressure plate, and a mixing matrix membrane; the outer frame is a U-shaped frame with a central through-hole and positioning grooves on its outer periphery; the U-shaped frame has mounting holes; the sealing ring is a square annular structure made of elastic material, and is placed in the positioning groove of the outer frame; the mixing matrix membrane is laid flat and covers the sealing ring, completely covering the central opening of the outer frame; the pressure plate is a U-shaped plate structure adapted to the shape of the outer frame, and has multiple through holes corresponding to the outer frame; bolts are sequentially passed through the through holes on the pressure plate, the area of ​​the mixing matrix membrane corresponding to the sealing ring, and the mounting holes on the outer frame, and finally tightened with nuts.

[0020] The present invention also provides a working process for the integrated photocatalysis-separation device, comprising the following steps:

[0021] Step 1: Pretreatment: First, close the inlet and outlet of the gas, connect the vacuum pump through the vacuum interface, and evacuate the entire cavity of the device to avoid side reactions and catalyst deactivation.

[0022] Step 2: Raw material gas introduction and reaction: Open the gas inlet and introduce moist CO2 gas into the shell at a certain flow rate;

[0023] Step 3: In-situ reaction and separation: Under the illumination of the lamp and the action of Cu(I)-MOF, a photoreduction reaction occurs, generating CO and O2. The mixed gas (CO / O2) generated by the reaction passes through the first mixed matrix membrane for the first separation.

[0024] Step 4: Multi-stage purification and product collection. The gas that has been initially enriched with CO through the first mixed matrix membrane enters the next chamber. The incompletely converted CO2 is further catalyzed and converted into CO in the second mixed matrix membrane, and then separated again. This process is repeated in multiple stages, with carbon dioxide being converted step by step and CO being purified step by step. Finally, high-purity CO gas escapes from the outlet.

[0025] The present invention also provides the application of the photocatalysis-separation integrated device in the photocatalytic generation of CO from CO and the separation of CO / O2.

[0026] The beneficial technical effects of this invention are as follows: During the synthesis process, the nano-confined space formed by the copolymer micelles precisely guides the nucleation and growth of Cu(I)-MOF, thereby controllably synthesizing uniformly sized and highly dispersed ultrafine nanocrystals, greatly increasing the exposed area of ​​active sites and shortening the gas diffusion path. More importantly, the local hydrophobic microenvironment provided by the copolymer effectively isolates water and oxygen, stabilizing the easily oxidized Cu(I) active centers and ensuring the material's intrinsic high selective adsorption capacity. Furthermore, the polymer chains attached to the MOF surface act like flexible "molecular hinges," not only improving particle dispersibility and interfacial compatibility during subsequent film formation, but also assisting in regulating the local flexibility of the MOF framework through dynamic conformational changes, thereby optimizing its recognition, adaptation, and dynamic adsorption process of CO molecules. Finally, this polymer protective shell also enhances the material's physical and chemical stability and extends its service life.

[0027] This invention successfully loads MOF materials onto a membrane, constructing a novel mixed matrix membrane with high CO / O2 selectivity. Leveraging the ease of membrane separation integration, it is combined with a photocatalytic device for efficient separation of O2 and CO. The developed catalyst is uniformly distributed on the mixed matrix membrane. Utilizing the affinity between Cu(I) sites and CO molecules, preferential CO transport within the membrane is promoted, achieving efficient separation of the target product CO. At the start of the reaction, moist CO2 enters the device through the inlet. In the first membrane layer, CO2 is catalytically converted to CO under the action of the surface catalyst, while the membrane performs preliminary separation of the mixed gas. Subsequently, incompletely converted CO2 continues to be catalytically converted to CO in the second membrane layer, achieving further separation and purification. Through this stepwise conversion and separation mechanism, high-purity CO is discharged from the outlet, realizing the efficient conversion and separation of CO2 to CO. Attached Figure Description

[0028] Figure 1 XRD pattern of Cu(I)-MOF;

[0029] Figure 2 The adsorption isotherms of Cu(I)-MOF for CO, CO2, and O2 are shown.

[0030] Figure 3 This is a scanning electron microscope image of a hybrid matrix membrane.

[0031] Figure 4 This is a schematic diagram of the integrated photocatalysis-separation device;

[0032] Figure 5 This is a top view of the photocatalysis-separation integrated device;

[0033] Figure 6 This is a mechanism diagram of a photocatalysis-separation integrated device;

[0034] Figure 7 This is a structural schematic diagram of the partition assembly;

[0035] Figure 8 The results of CO and O2 separation tests were performed on the mixed matrix membranes prepared in Examples 1-5 and Comparative Example 1.

[0036] Figure 9 This is a comparison of the selectivity of the photocatalysis-separation integrated device for CO and O2 with and without the mixed matrix membrane.

[0037] In the diagram: 1. Reactor shell; 2. Air inlet; 3. Air outlet; 4. Baffle assembly; 5. Mixing matrix membrane; 6. Lamp tube; 7. Vacuum interface. Detailed Implementation

[0038] The invention will now be further described with reference to the accompanying drawings.

[0039] Example 1: A method for preparing a Cu(I)-MOF hybrid matrix membrane:

[0040] S1. Dissolve 3,5-dimethyl-1,2,4-triazole Hdmtz (0.780 mmol) and 3,5-diethyl-1,2,4-triazole Hdetz (0.520 mmol) in a small amount of ethanol in a 2 L round-bottom flask, and add copper oxide nanoparticles (0.325 mmol) dispersed in ethanol in batches; at the same time, N2 bubbles are bubbled into the solution, and the mixture is refluxed for 3 days to finally obtain the product Cu(I)-MOF.

[0041] S2. Preparation of PEGBEM-POEM copolymer: The total amount of monomer was controlled at 10 g. Methyl methacrylate (MA) and poly(ethylene glycol) dodecyl ether methacrylate (PEGBEM) in a mass ratio of 7:3 were dissolved in 50 mL of ethyl acetate containing 0.01 g of azobisisobutyronitrile (AIBN). After purging with nitrogen at room temperature for 1 hour, the polymer solution was heated in an oil bath at 70 °C for 24 hours. Subsequently, the resulting homogeneous solution was precipitated by adding excess hexane. This precipitation process was repeated to remove byproducts. The product was completely dried overnight in a vacuum oven at room temperature to obtain the PEGBEM-POEM copolymer.

[0042] S3. Mix 1g of copolymer with 19g of water and stir for 12h to obtain copolymer solution. Mix PEGBEM-POEM copolymer solution and Cu(I)-MOF to obtain Cu(I)-MOF\PEGBEM-POEM casting solution. The mass ratio of Cu(I)-MOF to PEGBEM-POEM copolymer is 3:7. Use a 200 μm doctor blade to uniformly scrape the Cu(I)-MOF\PEGBEM-POEM casting solution onto a glass plate with a PAN base film. Then dry in a constant temperature and humidity chamber at 30 ℃ and 40 RH for 24 h to finally obtain Cu(I)-MOF mixed matrix film.

[0043] The Cu(I)-MOF of Example 1 was characterized by XRD, and the results are shown in the figure. Figure 1 The XRD pattern shows that Cu(I)-MOF has high crystallinity, with the main diffraction peaks located in the low-angle region, consistent with its three-dimensional porous structure. The pattern is consistent with the known Cu(I)-MOF structure, and no obvious impurity peaks were observed, indicating that the sample has high purity.

[0044] Adsorption isotherms of Cu(I)-MOF for CO, CO2, and O2 are as follows: Figure 2 As shown, the high selective adsorption performance of Cu(I)-MOF for CO is clearly demonstrated. This material exhibits excellent selective adsorption performance for CO in the pressure range of 0 to 1 bar. Under the same pressure conditions, the equilibrium adsorption capacity of CO is significantly higher than that of CO2 and O2. The CO adsorption isotherm shows a sharp upward trend in the low-pressure region (0-0.4 bar) and tends to reach adsorption saturation after about 0.6 bar, indicating the existence of strong adsorption sites in the material that specifically interact with CO molecules. Its adsorption mechanism conforms to typical chemisorption characteristics, and the maximum adsorption capacity can reach approximately 4.5 mmol·g⁻¹. -1 In contrast, the adsorption capacity of CO2 increased approximately linearly with increasing pressure, indicating that its adsorption with the material was mainly weak physical adsorption, with an adsorption capacity of less than 1 mmol·g at 1 bar. -1 The adsorption of O2 across the entire test pressure range was negligible, indicating that it was essentially not adsorbed by the material. This demonstrates that the material can achieve highly selective capture of CO in a mixed gas environment while effectively suppressing the competitive adsorption of CO2 and O2.

[0045] The obtained hybrid matrix film was characterized by scanning electron microscopy, and the results are as follows: Figure 3 This indicates that Cu(I)-MOF has been loaded onto the membrane.

[0046] Example 2

[0047] The difference between Example 2 and Example 1 is that the mass ratio of Cu(I)-MOF to PEGBEM-POEM copolymer is 5:5; all other conditions are exactly the same.

[0048] Example 3

[0049] The difference between Example 3 and Example 1 is that the mass ratio of Cu(I)-MOF to PEGBEM-POEM copolymer is 4:6; all other conditions are exactly the same.

[0050] Example 4

[0051] The difference between Example 4 and Example 1 is that the mass ratio of Cu(I)-MOF to PEGBEM-POEM copolymer is 2:8; all other conditions are exactly the same.

[0052] Example 5

[0053] The difference between Example 5 and Example 1 is that the mass ratio of Cu(I)-MOF to PEGBEM-POEM copolymer is 1:9; all other conditions are exactly the same.

[0054] Comparative Example 1: Preparation of PEBAX / Cu(I)-MOF membrane

[0055] PEBAX resin solution and Cu(I)-MOF were mixed and stirred to obtain Cu(I)-MOF\PEBAX casting solution, wherein the mass ratio of Cu(I)-MOF to PEBAX was 3:7. The Cu(I)-MOF\PEBAX casting solution was uniformly scraped onto a glass plate with a base film attached using a 200 μm doctor blade. Then, it was dried in a constant temperature and humidity chamber at 30 ℃ and 40 RH for 24 h to finally obtain Cu(I)-MOF mixed matrix film.

[0056] Example 6

[0057] like Figure 4-6 As shown, an integrated photocatalytic separation device includes a reactor shell 1. An inlet 2 is provided on one side of the reactor shell 1 for introducing raw material gas CO2. An outlet 3 is provided on the other side for discharging the separated and purified product, high-purity CO.

[0058] The shell contains multiple parallel partition assemblies 4, in which a mixing matrix membrane 5 is fixed. The partition assemblies 4 are fixed at equal intervals and parallel to the inner wall of the shell. The partition assemblies 4 divide the internal space of the device into multiple continuous, series-connected small chambers, which are continuous reaction-separation units.

[0059] Between adjacent partition assemblies 4, on the front side of the first partition assembly 4, and on the rear side of the last partition assembly 4, lamp tubes 6 are installed vertically between the front and rear sidewalls of the device to simulate solar xenon lamps or LED lamps of a specific wavelength.

[0060] The device is also provided with a vacuum port 7 on its side wall for connecting a vacuum pump to evacuate the system before the reaction.

[0061] See Figure 7 The partition assembly 4 includes an outer frame, a sealing ring, a pressure plate, and a mixing matrix membrane 5. The outer frame is a U-shaped frame with a central through-hole and positioning grooves on its outer edges. The U-shaped frame has mounting holes. The sealing ring is a square ring structure made of elastic material and is placed in the positioning groove of the outer frame. The mixing matrix membrane 5 is laid flat and covers the sealing ring, completely covering the central opening of the outer frame. The pressure plate is a U-shaped plate structure adapted to the shape of the outer frame and has multiple through holes corresponding to the outer frame. Bolts are passed sequentially through the through holes on the pressure plate, the area of ​​the mixing matrix membrane 5 corresponding to the sealing ring, and the mounting holes on the outer frame, and finally tightened with nuts.

[0062] The working process of the integrated photocatalysis-separation device system is as follows:

[0063] Step 1: System pretreatment: First, close the inlet 2 and outlet 3, and connect the vacuum pump through the vacuum port 7 to evacuate the entire system cavity to avoid side reactions and catalyst deactivation.

[0064] Step 2: Raw material gas introduction and reaction: Open gas inlet 2, and humid CO2 gas is introduced into the shell at a certain flow rate;

[0065] Step 3: In-situ reaction and separation: Under the illumination of lamp 6 and the action of Cu(I)-MOF, a photoreduction reaction occurs, generating CO and O2. The mixed gas (CO / O2) generated by the reaction passes through the first mixed matrix membrane 5 for the first separation.

[0066] Step 4: Multi-stage purification and product collection. The gas, preliminarily enriched with CO, passing through the first mixed matrix membrane 5, enters the next chamber. Incompletely converted CO2 continues to be catalytically converted to CO in the second mixed matrix membrane 5, and then separated again. This process is repeated in multiple stages, with carbon dioxide being converted and CO purified step by step. Finally, high-purity CO gas escapes from the outlet 3.

[0067] Example 7: Separation test of mixed matrix membrane for CO and O2

[0068] Using the photocatalysis-separation integrated device of Example 6, the separation of CO and O2 in the mixed matrix membranes prepared in Examples 1-5 and Comparative Example 1 was tested, and the results are as follows: Figures 8-9 As shown, under a CO2 inlet pressure of 2 atm, the system using a PEGBEM-POEM\Cu(I)-MOF (7:3) mixed matrix membrane can significantly increase the CO / O2 ratio from the initial 2:1 to 50:1, effectively promoting the forward reaction, and its separation effect is far superior to that of mixed matrix membranes with other ratios. Figure 9 As shown, the selectivity of CO / O2 is significantly improved after the mixed matrix membrane is added to the device.

[0069] The photocatalysis-separation integrated device is versatile and can be further extended to plasma-catalyzed CO2 conversion processes. In this system, plasma converts CO2 into a CO / O2 mixture with a ratio of approximately 2:1, and then the mixed matrix membrane prepared in this invention is used to achieve efficient separation of the products.

[0070] The key to the efficient CO separation of the Cu(I)-MOF lies in its unique "dynamic response" framework. In the presence of CO molecules, the material's framework undergoes reversible local structural deformation, driving a dynamic change in the geometric configuration of the coordinatingly unsaturated Cu(I) centers. Specifically, the framework's flexibility allows the Cu(I) ion's geometry to reversibly transform into a distorted tetrahedral geometry. This configurational change essentially provides Cu(I) with a new, usable coordination site, thereby achieving strong and specific adsorption of CO. These strong chemisorption sites, induced by the guest molecule (CO) and specific to CO, enable the material to efficiently and selectively capture CO at room temperature, thus achieving excellent separation performance.

[0071] The device contains multiple partition components 4 and lamps 6, which enable photocatalysis and separation to be carried out multiple times, thereby continuously producing the product gas CO and greatly improving the separation efficiency. It makes full use of the affinity between Cu(I) sites and CO molecules to promote the preferential transfer of CO in the membrane, so that the catalytically generated CO can efficiently pass through the mixed matrix membrane, while O2 is enriched on the reaction side, achieving highly selective collection of the target product CO.

Claims

1. A method for preparing a Cu-MOF hybrid matrix membrane, characterized in that: Cu in Cu-MOF is monovalent; The preparation method includes the following steps: (1) Dissolve 3,5-dimethyl-1,2,4-triazole and 3,5-diethyl-1,2,4-triazole in ethanol, add copper oxide nanoparticles dispersed in ethanol, and reflux for 3 days under N2 conditions to obtain Cu-MOF. In step (1), the molar ratio of 3,5-dimethyl-1,2,4-triazole to 3,5-diethyl-1,2,4-triazole is 3:2; the molar ratio of the total amount of 3,5-dimethyl-1,2,4-triazole to 3,5-diethyl-1,2,4-triazole and the molar ratio of copper oxide nanoparticles is 4:

1. (2) Methyl methacrylate and poly(ethylene glycol) dodecyl ether methacrylate PEGBEM were mixed and dissolved in ethyl acetate containing azobisisobutyronitrile (AIBN). After being purged with N2, the mixture was reacted at 70 °C for 24 hours to obtain a polymer solution. Then, excess hexane was added to precipitate the homogeneous solution. This precipitation process was repeated to remove byproducts. The product was dried overnight in a vacuum oven to obtain the PEGBEM-POEM copolymer. (3) Mix the PEGBEM-POEM copolymer obtained in step (2) with water and stir for 12 hours to obtain a PEGBEM-POEM copolymer solution. (4) Mix the Cu-MOF obtained in step (1) with the PEGBEM-POEM copolymer solution obtained in step (3) and stir to obtain a casting solution. The mass ratio of Cu-MOF to PEGBEM-POEM copolymer is 3:

7. (5) Using a 200 μm scraper, the casting solution was uniformly scraped onto a glass plate with a PAN substrate film attached. Then, it was dried in a constant temperature and humidity chamber at 30 °C and 40% RH for 24 h to finally obtain a Cu-MOF mixed matrix film. The Cu-MOF hybrid matrix membrane can separate CO / O2.

2. The method for preparing Cu-MOF hybrid matrix membrane according to claim 1, characterized in that: In step (2), the mass ratio of methyl methacrylate to PEGBEM is 7:3, and the mass ratio of the total mass of methyl methacrylate and PEGBEM to the mass ratio of azobisisobutyronitrile (AIBN) is 10:0.

01.

3. The method for preparing Cu-MOF hybrid matrix membrane according to claim 1, characterized in that: In step (3), the mass concentration of the PEGBEM-POEM copolymer solution is 5%.

4. A Cu-MOF hybrid matrix membrane prepared by the preparation method according to any one of claims 1-3.

5. A photocatalysis-separation integrated device, characterized in that: It includes a reactor shell, with an air inlet on one side for introducing raw material gas CO2 and an air outlet on the other side for discharging the separated and purified product high-purity CO. The shell contains multiple parallel partition assemblies, in which the Cu-MOF mixed matrix membrane of claim 4 is fixed. The partition assemblies are fixed at equal intervals and parallel to the inner wall of the shell. The partition assemblies divide the internal space of the device into multiple continuous, series-connected small chambers. These continuous small chambers are continuous reaction-separation units. Between adjacent partition assemblies, on the front side of the first partition assembly, and on the rear side of the last partition assembly, lamp tubes are installed vertically between the front and rear sidewalls of the device to simulate solar xenon lamps or LED lamps of a specific wavelength. The device is also equipped with a vacuum port on its side wall for connecting a vacuum pump to evacuate the device before the reaction.

6. The photocatalysis-separation integrated device according to claim 5, characterized in that: The workflow of the integrated photocatalysis-separation device includes the following steps: Step 1: Pretreatment: First, close the inlet and outlet of the gas, connect the vacuum pump through the vacuum interface, and evacuate the entire cavity of the device to avoid side reactions and catalyst deactivation. Step 2: Raw material gas introduction and reaction: Open the gas inlet and introduce moist CO2 gas into the shell at a certain flow rate; Step 3: In-situ reaction and separation: Under the illumination of the lamp and the action of Cu-MOF, a photoreduction reaction occurs to generate CO and O2. The mixed gas CO / O2 generated by the reaction is separated for the first time through the first mixed matrix membrane. Step 4: Multi-stage purification and product collection: The gas that has been initially enriched with CO through the first layer of mixed matrix membrane enters the next chamber. The incompletely converted CO2 is further catalyzed and converted into CO in the second layer of mixed matrix membrane, and then separated again. This process is repeated in multiple stages, with CO2 being converted step by step and CO being purified step by step. Finally, high-purity CO gas escapes from the outlet.

7. The application of the photocatalysis-separation integrated device as described in claim 5 in the photocatalytic generation of CO from CO and the separation of CO / O2.

Images