Porous bipolar membrane as well as preparation method and application thereof
By loading cationic ionomer materials onto a porous substrate to form a porous bipolar membrane, the stability and catalytic activity issues of commercial bipolar membranes in the electrocatalytic carbon dioxide reduction process were solved, and a highly efficient carbon dioxide reduction reaction was achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-08
- Publication Date
- 2026-03-10
AI Technical Summary
Commercial bipolar membranes suffer from poor stability and limited enhancement of catalytic activity and selectivity by the anion exchange layer during electrocatalytic carbon dioxide reduction.
A porous bipolar membrane is formed by loading cationic ionomer materials with anion exchange capacity onto a porous substrate and regulating them with ionomer functionalization groups to improve the cathode pH inhibition of hydrogen evolution and optimize the interfacial activity and selectivity of the electrocatalytic carbon dioxide reduction reaction.
It significantly improves the stability and catalytic performance of bipolar membranes, provides efficient material transport channels, and achieves highly selective and efficient carbon dioxide reduction reactions.
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Figure CN121629464A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the technical field of ion exchange membranes and membrane electrode assemblies, specifically relating to a porous anion exchange layer coated composite bipolar membrane, its preparation method, and its application in electrocatalytic carbon dioxide reduction. Background Technology
[0002] Carbon dioxide resource utilization technology has become an important pathway for mitigating climate change and promoting the transition to clean energy. Electrocatalytic carbon dioxide reduction (COD) converts carbon dioxide into high-value-added chemicals such as carbon monoxide, methanol, and ethylene using renewable electricity, which not only helps reduce greenhouse gas emissions but also provides carbon source support for "green chemistry." Compared to thermochemical and biological conversion pathways, electrochemical methods offer advantages such as milder conditions, cleaner pathways, and high compatibility with the power grid, making them a key technology for achieving closed-loop carbon dioxide utilization. However, electrocatalytic COD reduction faces unique challenges under different electrolysis environments: while alkaline systems are beneficial for improving reaction selectivity, carbon dioxide readily reacts with hydroxides to form bicarbonate / carbonate, causing carbon loss and salting out, and carbon dioxide separation in the tail gas is difficult; while acidic environments, although industrially compatible, suffer from severe hydrogen evolution side reactions and poor electrode stability. These factors collectively limit the overall energy efficiency and application feasibility of electrocatalytic COD reduction systems. Developing membrane electrode systems with strong adaptability, tunable interfacial environments, and both mass transfer and charge control capabilities has become a core scientific issue driving the practical application of electrocatalytic COD reduction.
[0003] Membrane electrode electrolyzers based on bipolar membranes hold promise for achieving highly selective and high-conversion electrocatalytic carbon dioxide reduction. The bipolar membrane consists of an anion exchange layer with cation conductivity and a cation exchange layer with anion conductivity. As a membrane structure that also provides acid / base isolation, the bipolar membrane, when forward biased, has the anion exchange layer facing the cathode and the cation exchange layer facing the anode. This allows the anion exchange layer to increase the cathode pH and suppress hydrogen evolution, while the cation exchange layer inhibits carbonate / bicarbonate formation and shuttling. This approach is expected to overcome the challenges of low product selectivity in acidic electrolyzers and low carbon dioxide utilization in alkaline electrolyzers. Based on these advantages, bipolar membranes have been applied in carbon dioxide electrolysis and liquid product separation systems.
[0004] During the operation of bipolar membrane electrolyzers, the cathode electrocatalytic carbon dioxide reduction reaction is often accompanied by the generation and migration of carbonate (hydrocarbonate) ions to the anion exchange layer-cation exchange layer interface. Carbon dioxide precipitation or salt deposition occurs at the interface, leading to membrane peeling and decreased stability. Researchers have attempted to alleviate these problems by perforating the anion exchange layer and etching micropores in the cation exchange layer, but precise control of the pore distribution is difficult, and there is a lack of structural continuity and scale-up potential. Furthermore, since electrocatalytic carbon dioxide reduction occurs at the catalyst-anion exchange layer interface, the chemical composition of the anion exchange layer determines the catalytic interface structure and microenvironment, which has a crucial impact on the catalytic activity and selectivity of electrocatalytic carbon dioxide reduction. Commercially available bipolar membranes are limited in variety, and systematic research on the influence of the anion exchange layer on the catalytic activity and selectivity of electrocatalytic carbon dioxide reduction is lacking. Summary of the Invention
[0005] The purpose of this invention is to overcome the defects in the prior art, solve the problems of poor stability and limited improvement of the catalytic activity and selectivity of the bipolar membrane anion exchange layer on the electrocatalytic carbon dioxide reduction in current commercial bipolar membranes, and provide a porous bipolar membrane, its preparation method and application.
[0006] This invention utilizes an anion exchange layer to increase the cathode pH and suppress hydrogen evolution by loading a cationic ion polymer material with anion exchange capacity onto a porous substrate. Furthermore, it combines the functional groups of the ionomer to regulate and improve the interfacial activity and catalytic selectivity of the electrocatalytic carbon dioxide reduction reaction. At the same time, the introduction of the porous structure provides an efficient transport channel to alleviate gas-liquid aggregation and mass migration, significantly improving the stability of the bipolar membrane in use.
[0007] The specific technical solution adopted in this invention is as follows: In a first aspect, the present invention provides a method for preparing a porous bipolar film, as detailed below: S1: Dissolve the cationic ionomer material with anionic conductivity in alcohol to obtain a first solution; disperse the porous substrate in an aqueous phase or an organic solvent to obtain a second solution; mix the first solution and the second solution at a volume percentage of (40-10):(60-90), and then add solvent to form a homogeneous slurry; S2: The slurry is loaded onto one side of the first substrate material, and then the second substrate material is fixed on that side to obtain a porous bipolar membrane.
[0008] Preferably, the cationic ionomer material is one or more of quaternary ammonium salt ionomers, pyridine ionomers, imidazole ionomers, piperidine ionomers, pyrrole ionomers, or spirocyclic ionomers; the concentration of the cationic ionomer material in the first solution is 2.5 wt%-20 wt%.
[0009] Preferably, the porous substrate is a monodisperse spherical material or a membrane material with a porous structure, with a pore size of 20 nm-100 μm and a porosity of 50%-90%; in the second solution, the concentration of the porous substrate is 5-50 mg / mL; The monodisperse spherical material is one or more of polystyrene microspheres, polymethyl methacrylate microspheres, polyvinyl chloride microspheres, polypropylene microspheres, or titanium dioxide microspheres. The porous membrane material is one or more of polytetrafluoroethylene, polyethersulfone, polypropylene, polyphenylene sulfide, or polyester porous membrane.
[0010] Preferably, the solvent is one or more of water, N-methylpyrrolidone, acetone, acetonitrile, methanol, ethanol, isopropanol, and N,N-dimethylformamide.
[0011] Preferably, S2 is as follows: First, the slurry is coated onto the first substrate material by spraying, spin coating or scraping, and then dried and cured at 40-100 ℃ for 5-120 min; then, it is transferred to the second substrate material to form an integrated membrane electrode assembly, thus obtaining a porous bipolar membrane.
[0012] Preferably, the first substrate material is an electrode substrate and the second substrate material is a commercially available counter electrode film; or the first substrate material is a commercially available counter electrode film and the second substrate material is an electrode substrate.
[0013] Furthermore, the electrode substrate is carbon paper, carbon cloth, or metal foam, and the commercially available counter electrode film is one or any combination of Nafion®, 3M™ PFSA Membranes, Flemion®, Aquivion®, and GORE-SELECT®.
[0014] Preferably, the thickness of the slurry coating loaded on the first substrate material is 0.5~50 µm.
[0015] In a second aspect, the present invention provides a porous bipolar membrane obtained by the preparation method described in any one of the first aspects.
[0016] Thirdly, the present invention provides an application of the porous bipolar membrane described in the first aspect in a membrane electrode system, wherein the porous bipolar membrane is placed between the cathode and anode of an electrocatalytic carbon dioxide reduction membrane electrode electrolytic cell and used for carbon dioxide reduction reaction under forward bias conditions; the electrolyte used is pure water or an aqueous solution containing 0-3 M potassium ions.
[0017] Compared with the prior art, the present invention has the following advantages: (1) The porous structure has high porosity, which can alleviate gas-liquid accumulation and provide an efficient transport channel for material migration.
[0018] (2) Designing and screening cationic ionomers with different functional groups, charge densities and main chain structures can systematically study the performance of improving the selectivity, single-pass conversion efficiency and long-term operation stability of electrocatalytic carbon dioxide reduction products. Attached Figure Description
[0019] Figure 1 This is a scanning electron microscope image of the porous bipolar membrane prepared in Example 1.
[0020] Figure 2 This is the electrocatalytic selectivity diagram of Example 1.
[0021] Figure 3 This is the electrocatalytic selectivity diagram for Example 2.
[0022] Figure 4 This is the electrocatalytic selectivity diagram for Example 3.
[0023] Figure 5 This is the electrocatalytic selectivity diagram for Example 4.
[0024] Figure 6 This is the electrocatalytic stability diagram of Example 1.
[0025] Figure 7 This is the electrocatalytic stability diagram of Example 2.
[0026] Figure 8 This is the potential-time diagram of Example 2 under multi-step constant current testing, with a current density difference of 50 mA / cm² per step. -2 Each step is maintained for 600 seconds.
[0027] Figure 9 This is a potential-time graph under a comparative multi-step constant current test, with a current density of 20 mA cm⁻¹ in the first step. -2 The current density in the second step is 60 mA cm⁻¹ -2 .
[0028] Figure 10 This is a comparative electrocatalytic performance graph. Detailed Implementation
[0029] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below. Technical features in various embodiments of the present invention can be combined accordingly without mutual conflict.
[0030] This invention provides a method for preparing a porous bipolar membrane, as detailed below: S11: Dissolve the cationic ionomer material with anionic conductivity in alcohol to obtain the first solution.
[0031] As a preferred embodiment of the present invention, the cationic ionomer material may be one or more of the following: quaternary ammonium salt ionomer, pyridine ionomer, imidazole ionomer, piperidine ionomer, pyrrole ionomer, or spirocyclic ionomer.
[0032] Specifically, the structure and source of the cationic ionomer materials used are shown in Table 1.
[0033] Table 1 In a preferred embodiment of the present invention, the concentration of the cationic ionomer material in the first solution is 2.5 wt%-20 wt%.
[0034] S12: Disperse the porous substrate in an aqueous phase or an organic solvent to obtain a second solution.
[0035] As a preferred embodiment of the present invention, the porous substrate can be a monodisperse spherical material or a membrane material with a porous structure, with a pore size of 20 nm-100 μm and a porosity of 50%-90%.
[0036] Specifically, monodisperse spherical materials can be one or more of polystyrene microspheres, polymethyl methacrylate microspheres, polyvinyl chloride microspheres, polypropylene microspheres, or titanium dioxide microspheres. Membrane materials with porous structures can be one or more of polytetrafluoroethylene, polyethersulfone, polypropylene, polyphenylene sulfide, or polyester porous membranes.
[0037] In a preferred embodiment of the present invention, the concentration of the porous substrate in the second solution is 5-50 mg / mL.
[0038] S13: Mix the first solution obtained in S11 with the second solution obtained in S12 at a volume percentage of (40-10):(60-90), and then add solvent to form a uniform slurry.
[0039] As a preferred embodiment of the present invention, the solvent may be one or more of water, N-methylpyrrolidone (NMP), acetone, acetonitrile, methanol, ethanol, isopropanol, and N,N-dimethylformamide.
[0040] S2: Load the slurry obtained in S13 onto one side of the first substrate material, and then fix the second substrate material on that side to obtain a porous bipolar membrane.
[0041] In a preferred embodiment of the present invention, the thickness of the slurry coating loaded on the first substrate material is 0.5~50 µm.
[0042] In a preferred embodiment of the present invention, the steps are as follows: First, the slurry is coated onto the first substrate material by spraying, spin coating, scraping or direct mechanical bonding, and then dried and cured at a temperature of 40-100 ℃ for 5-120 min. Next, it is formed into an integrated membrane electrode assembly with the second substrate material by transfer method (e.g., hot pressing or mechanical clamping), and after drying, a porous bipolar membrane is obtained.
[0043] Specifically, when using the hot pressing method, the hot pressing assembly conditions are 60-120 ℃, 0.3-1 MPa, and 5-15 min.
[0044] In a preferred embodiment of the present invention, the first substrate material is an electrode substrate, and the second substrate material is a commercially available counter electrode film; or the first substrate material is a commercially available counter electrode film, and the second substrate material is an electrode substrate.
[0045] Specifically, the electrode substrate can be carbon paper, carbon cloth, or metal foam, such as the Sigrette® series from SGL Carbon, Toray Carbon Paper, Freudenberg carbon paper, AvCarb® carbon paper, CeTech carbon cloth, Spectracarb® carbon paper, or equivalents. Commercial counter electrode films can be Nafion®, 3M™ PFSAMembranes, Flemion®, Aquivion®, GORE-SELECT®, or equivalents, or any combination thereof.
[0046] The porous bipolar membrane obtained by the above preparation method can be applied to membrane electrode systems. Taking the carbon dioxide reduction reaction as an example, the specific application method is as follows: S1: The porous bipolar membrane of the present invention is placed between the cathode and anode of the electrocatalytic carbon dioxide reduction membrane electrode electrolysis cell.
[0047] S2: Assemble the electrolytic cell, connect the gas and liquid pipelines and circuits, and start the test after ensuring that the device is leak-proof. It is used for carbon dioxide reduction under forward bias conditions. During the carbon dioxide reduction reaction, the electrolyte used is pure water or an aqueous solution containing 0-3 M potassium ions, and the pH can be acidic, neutral, or alkaline.
[0048] In practical applications, the first ion exchange layer of the bipolar membrane, also known as the anion exchange layer, is in direct contact with the cathode of the electrolytic cell, while the second ion exchange layer, also known as the proton exchange layer, is in direct contact with the anode of the electrolytic cell. The anode can be selected from platinum, iridium, ruthenium, palladium, and their oxides or alloys, supported by titanium fiber felt or carbon paper.
[0049] The porous bipolar membrane prepared by this invention has good catalytic performance and electrolytic stability. At the same time, the porous channels can alleviate gas-liquid accumulation and mass migration, providing an efficient transport channel. Furthermore, the introduction of various cationic polymers with anion exchange capacity enables the regulation of catalytic performance.
[0050] The preparation method of the present invention and the performance of the obtained porous bipolar membrane will be specifically illustrated below through examples and comparative examples.
[0051] Example 1 In this embodiment, a porous bipolar membrane was prepared and applied to a carbon dioxide reduction reaction, as detailed below: (1) Mix 1 mL QAPEEK (i.e., quaternary ammonium polyether ether ketone, 5 wt%, ethanol solution) and 400 uL monodisperse polystyrene microspheres (10 mg, aqueous solution), add 1 mL ethanol solution, and shake for 3 min in an ice-water mixture at 0 ℃ to obtain a uniform slurry.
[0052] (2) The slurry from step (1) was uniformly sprayed onto the gas diffusion electrode (YLS-30T, 2.5 cm * 2.5 cm) supported on the silver catalyst using a spraying method. After final drying, the slurry loading was 2.2-3 mg / cm³. 2 .
[0053] (3) The electrode obtained in step (2) is used as the cathode to assemble a membrane electrode electrolytic cell. The diaphragm used is a Nafion® N117 proton exchange membrane (i.e., the second substrate material). High-purity CO2 is continuously introduced into the back of the gas diffusion electrode at a flow rate of 40 mL / min. The anode electrode is an iridium-plated titanium felt and a peristaltic pump is used to circulate 0.01 M potassium bicarbonate electrolyte.
[0054] (4) During the electrolysis process in step (3), an electrochemical workstation is used to record electrochemical parameters, and online gas chromatography is used to detect reaction products.
[0055] The scanning electron microscope for the electrodes obtained in step (2) is as follows: Figure 1 As shown in the figure, the porous anion exchange layer is uniformly coated on the surface of the gas diffusion electrode, and the coating has no obvious cracks.
[0056] Figure 2 The image shows the electrocatalytic carbon dioxide reduction selectivity of the prepared porous bipolar membrane. Experimental results indicate that the prepared porous bipolar membrane exhibits high carbon monoxide selectivity across a wide current density range. Figure 6 Example 1 at 150 mAcm -2 The system stability diagram shows that the prepared porous bipolar membrane has the ability to operate efficiently for a long time at industrial-grade current densities.
[0057] Example 2 In this embodiment, a porous bipolar membrane was prepared and applied to a carbon dioxide reduction reaction, as detailed below: (1) Mix 150 uL QAPEEK (5 wt%, ethanol solution) and 400 uL monodisperse polystyrene microspheres (10 mg, aqueous solution), add 1 mL ethanol solution, and shake for 3 min in an ice-water mixture at 0 ℃ to obtain a uniform slurry.
[0058] (2) The slurry from step (1) was uniformly sprayed onto a gas diffusion electrode (YLS-30T, 2.5 cm * 2.5 cm) loaded with silver catalyst using a spraying method. After final drying, the slurry loading was 1.5-2.5 mg / cm³. 2 .
[0059] (3) Assemble a membrane electrode electrolytic cell using the electrode in step (2) as the cathode. The membrane used is a Nafion® N117 proton exchange membrane. High-purity CO2 is continuously introduced into the back of the gas diffusion electrode at a flow rate of 40 mL / min. The anode electrode is an iridium-plated titanium felt, and a peristaltic pump is used to circulate 0.1 M sulfuric acid electrolyte.
[0060] (4) During the electrolysis process in step (3), an electrochemical workstation is used to record electrochemical parameters, and online gas chromatography is used to detect reaction products.
[0061] Figure 3 The graph shows the selectivity of the prepared porous bipolar membrane for electrocatalytic carbon dioxide reduction. Figure 8 This corresponds to the potential-time plot; and Figure 9 Comparative potential-time plot and Figure 10 Compared with the experimental results, the selected carbon dioxide reduction selectivity of the commercial bipolar membrane electrocatalysis was compared with that of the prepared porous bipolar membrane. Under the same conditions, the prepared porous bipolar membrane has higher carbon monoxide product selectivity, operational stability and lower interfacial impedance.
[0062] Figure 7 Example 2 at 100 mA cm -2 System stability diagram; and Figure 9 Comparative potential-time plot and Figure 10 Compared with the experimental results, the selected carbon monoxide reduction profile of the commercial bipolar membrane electrocatalysis shows that the prepared porous bipolar membrane exhibits higher carbon monoxide product selectivity under the same conditions, and the bipolar membrane structure stability is significantly improved. Figure 7 The system at 100 mA cm -2 It operated stably for 7 hours at current density, while the comparative example Figure 9 The potential increases sharply in less than 20 minutes due to the peeling of the bipolar membrane.
[0063] Example 3 In this embodiment, a porous bipolar membrane was prepared and applied to a carbon dioxide reduction reaction, as detailed below: (1) Mix 150 uL QAPPT (5 wt%, a mixed solution of ethanol and DMSO) and 400 uL monodisperse polystyrene microspheres (10 mg, aqueous solution), add 1 mL of ethanol solution, and shake for 3 min in an ice-water mixture at 0 ℃ to obtain a homogeneous slurry.
[0064] (2) The slurry from step (1) was uniformly sprayed onto a gas diffusion electrode (YLS-30T, 2.5 cm * 2.5 cm) loaded with silver catalyst using a spraying method. After final drying, the slurry loading was 1.5-2.5 mg / cm³. 2 .
[0065] (3) Assemble a membrane electrode electrolytic cell using the electrode in step (2) as the cathode. The membrane used is a Nafion® N117 proton exchange membrane. High-purity CO2 is continuously introduced into the back of the gas diffusion electrode at a flow rate of 40 mL / min. The anode electrode is an iridium-plated titanium felt, and 0.1 M sulfuric acid electrolyte is circulated through it using a peristaltic pump.
[0066] (4) During the electrolysis process in step (3), an electrochemical workstation is used to record electrochemical parameters, and online gas chromatography is used to detect reaction products.
[0067] Figure 4 The graph shows the selectivity of the prepared porous bipolar membrane for electrocatalytic carbon dioxide reduction. Experimental results are consistent with... Figure 3 The comparison shows that porous bipolar membranes prepared using different cationic ionomers can all achieve high carbon monoxide selectivity.
[0068] Example 4 In this embodiment, a porous bipolar membrane was prepared and applied to a carbon dioxide reduction reaction, as detailed below: (1) Mix 150 uL PiperION (5 wt%, ethanol solution) and 400 uL monodisperse polystyrene microspheres (10 mg, aqueous solution), add 1 mL ethanol solution, and shake for 3 min in an ice-water mixture at 0 ℃ to obtain a homogeneous slurry.
[0069] (2) The slurry from step (1) was uniformly sprayed onto a gas diffusion electrode (YLS-30T, 2.5 cm * 2.5 cm) loaded with silver catalyst using a spraying method. After final drying, the slurry loading was 1.5-2.5 mg / cm³. 2 .
[0070] (3) Assemble a membrane electrode electrolytic cell using the electrode in step (2) as the cathode. The membrane used is a Nafion® N117 proton exchange membrane. High-purity CO2 is continuously introduced into the back of the gas diffusion electrode at a flow rate of 40 mL / min. The anode electrode is an iridium-plated titanium felt, and 0.1 M sulfuric acid electrolyte is circulated through it using a peristaltic pump.
[0071] (4) During the electrolysis process in step (3), an electrochemical workstation is used to record electrochemical parameters, and online gas chromatography is used to detect reaction products.
[0072] Figure 5 The graph shows the selectivity of the prepared porous bipolar membrane for electrocatalytic carbon dioxide reduction.
[0073] Comparative Example This comparative example uses a commercially purchased FuMA-Tech Fumasep FBM-PK bipolar membrane in a carbon dioxide reduction reaction, as detailed below: (1) Under forward bias conditions, FuMA-Tech Fumasep FBM-PK bipolar membrane is used, that is, the anion exchange layer is in direct contact with the cathode of the electrolytic cell, and the proton exchange layer is in direct contact with the anode of the electrolytic cell.
[0074] (2) Assemble the membrane electrode electrolytic cell. High-purity CO2 is continuously introduced into the back of the gas diffusion electrode at a flow rate of 40 mL / min. 0.1 M sulfuric acid electrolyte is circulated into the anode using a peristaltic pump.
[0075] (3) Electrochemical parameters were recorded using an electrochemical workstation during the electrolysis process; and reaction products were detected using online gas chromatography.
[0076] This invention focuses on the composition and structure regulation of bipolar membrane anion exchange layers, designing a controllable porous support-ionomer composite structure. This structure enhances interfacial stability while achieving precise control of gas-liquid transport and local environment, thereby improving the carbon dioxide conversion efficiency and stability of bipolar membrane electrode electrolyzers. The introduction of the porous structure provides an efficient transport channel to alleviate gas-liquid aggregation and mass migration. Combined with the regulation by functionalized groups in the ionomer, it is expected to achieve high conversion efficiency and long-term stability in bipolar membrane electrode electrolyzers.
[0077] The bipolar membrane of this invention can be used for electrocatalytic carbon dioxide reduction under forward bias conditions, effectively regulating the microenvironment at the cathode interface, suppressing hydrogen evolution side reactions, and alleviating gas-liquid aggregation and ion migration resistance. This invention has advantages such as simple integrated membrane-electrode assembly, low interfacial impedance, high operational stability, and good product selectivity, making it suitable for clean energy conversion and carbon resource utilization.
[0078] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the invention. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, all technical solutions obtained through equivalent substitution or transformation fall within the protection scope of the present invention.
Claims
1. A method for producing a porous bipolar membrane, characterized by, Specifically as follows: S1: dissolving a cationic ionomer material with anion conduction ability in alcohol to obtain a first solution; dispersing a porous substrate in an aqueous phase or an organic solvent to obtain a second solution; mixing the first solution and the second solution according to a volume percentage ratio of (40-10):(60-90), and then adding a solvent to form a uniform slurry; S2: loading the slurry on one side of a first substrate material, and then fixing a second substrate material on the side to obtain a porous bipolar membrane.
2. A method for preparing a porous bipolar membrane according to claim 1, characterized in that, The cationic ionomer material is one or more of a quaternary ammonium salt type ionomer, a pyridine type ionomer, an imidazole type ionomer, a piperidine type ionomer, a pyrrole type ionomer, or a spiro type ionomer; in the first solution, the concentration of the cationic ionomer material is 2.5 wt%-20 wt%.
3. The method for preparing a porous bipolar membrane according to claim 1, wherein The porous substrate is a monodisperse particle size spherical material or a membrane material with a porous structure, the pore size is 20 nm-100 μm, and the porosity is 50%-90%; in the second solution, the concentration of the porous substrate is 5-50 mg / mL; The monodisperse particle size spherical material is one or more of polystyrene microspheres, polymethyl methacrylate microspheres, polyvinyl chloride microspheres, polypropylene microspheres, or titanium dioxide microspheres; The membrane material with a porous structure is one or more of polytetrafluoroethylene, polyether sulfone, polypropylene, polyphenylene sulfide, or polyester porous membrane.
4. The method for preparing a porous bipolar membrane according to claim 1, characterized in that, The solvent is one or more of water, N-methyl pyrrolidone, acetone, acetonitrile, methanol, ethanol, isopropanol, and N,N-dimethylformamide.
5. The method for preparing a porous bipolar membrane according to claim 1, characterized in that, S2 is specifically as follows: First, the slurry is coated on the first substrate material in a spraying, spin coating, or blade coating manner, and then dried and cured at 40-100 ℃ for 5-120 min; then, the membrane electrode integrated assembly is formed with the second substrate material by transfer printing to obtain a porous bipolar membrane.
6. The method for preparing a porous bipolar membrane according to claim 1, characterized by, The first substrate material is an electrode substrate, and the second substrate material is a commercial counter electrode membrane; Or the first substrate material is a commercial counter electrode membrane, and the second substrate material is an electrode substrate.
7. A method for preparing a porous bipolar membrane according to claim 6, characterized in that, The electrode substrate is one or any combination of carbon paper, carbon cloth, or metal foam, and the commercial counter electrode membrane is one or any combination of Nafion®, 3M™ PFSA Membranes, Flemion®, Aquivion®, and GORE-SELECT®.
8. The method of claim 1, wherein the porous bipolar membrane is prepared by the steps of: The thickness of the slurry coating layer loaded on the first substrate material is 0.5-50 μm.
9. A porous bipolar membrane prepared by the method of any one of claims 1-8.
10. Use of the porous bipolar membrane according to claim 9 in a membrane electrode assembly, characterized in that The porous bipolar membrane is placed between the cathode and the anode of an electrocatalytic carbon dioxide reduction membrane electrode electrolytic cell and used for carbon dioxide reduction reaction under a positive bias condition; the electrolyte used is pure water or an aqueous solution containing 0-3 M potassium ions. The porous bipolar membrane is placed between the cathode and the anode of an electrocatalytic carbon dioxide reduction membrane electrode electrolytic cell and used for carbon dioxide reduction reaction under a positive bias condition; the electrolyte used is pure water or an aqueous solution containing 0-3 M potassium ions.