Porous electrode-supported electrolyte membrane and method for producing the same

Abstract

Provided is a porous electrode-supporting electrolyte membrane 20 to be used in a gas reduction device for reducing carbon dioxide, the porous electrode-supporting electrolyte membrane 20 having an electrolyte membrane 6 and a porous reduction electrode 5 embedded in the electrolyte membrane 6, wherein part of the porous reduction electrode 5 is exposed at a prescribed surface of the porous electrode-supporting electrolyte membrane 20.

Description

[Technical Field]

[0001] The present invention relates to a porous electrode-supported electrolyte membrane and a method for producing a porous electrode-supported electrolyte membrane. [Background technology]

[0002] Carbon dioxide reduction technology has attracted attention from the perspectives of preventing global warming and ensuring a stable energy supply. Devices related to carbon dioxide reduction technology include reduction devices using artificial photosynthesis technology and reduction devices using electrolytic reduction technology. Artificial photosynthesis technology promotes the oxidation of water and the reduction of carbon dioxide by irradiating an oxidation electrode made of a photocatalyst with light. Electrolytic reduction technology promotes the oxidation of water and the reduction of carbon dioxide by applying a voltage between an oxidation electrode made of a metal and a reduction electrode. Artificial photosynthesis technology using sunlight and electrolytic reduction technology using electricity derived from renewable energy have attracted attention as technologies that can recycle carbon dioxide into carbon monoxide, formic acid, hydrocarbons such as ethylene, and alcohols such as methanol and ethanol, and have been actively researched in recent years.

[0003] Artificial photosynthesis technology and carbon dioxide electrolytic reduction technology have used a reaction system in which a reduction electrode is immersed in an aqueous solution and carbon dioxide dissolved in the solution is supplied to the reduction electrode for reduction (see Non-Patent Documents 1 and 2). However, in this carbon dioxide reduction method, there are limitations to the concentration of carbon dioxide dissolved in the aqueous solution and the diffusion coefficient of carbon dioxide in the aqueous solution, which limits the amount of carbon dioxide that can be supplied to the reduction electrode.

[0004] To address this issue, research is being conducted into supplying gaseous carbon dioxide to the reduction electrode in order to increase the amount of carbon dioxide supplied to the reduction electrode. According to Non-Patent Document 3, by using a reaction device having a structure that can supply gaseous carbon dioxide to the reduction electrode, the amount of carbon dioxide supplied to the reduction electrode is increased, and the carbon dioxide reduction reaction is promoted. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] Satoshi Yotsuhashi and 6 others, “CO2 Conversion with Light and Water by GaN Photoelectrode”, Japanese Journal of Applied Physics, 51, 2012, p.02BP07-1-p.02BP07-3 [Non-patent document 2] Yoshio Hori and others, “Formation of Hydrocarbons in the Electrochemical Reduction of Carbone Dioxide at a Copper Electrode in Aqueous Solution”, Journal of the Chemical Society, 85(8), 1989, p.2309-p.2326 [Non-patent document 3] Qingxin Jia and 2 others, “Direct Gas-phase CO2Reduction for Solar Methane Generation Using a Gas Diffusion Electrode with a BiVO4:Mo and a Cu-In-Se Photoanode”, Chemistry Letter, 47, 2018, p.436-439 Summary of the Invention [Problem to be solved by the invention]

[0006] The carbon dioxide reduction reaction shown in formulas (1) to (4) proceeds in combination with the water oxidation reaction shown in formula (5).

[0007] CO2+ 2H + + 2e - → CO + HO (1) CO2+ 2H + + 2e - → HCOOH (2) CO2+ 6H + + 6e - → CH3OH + H2O (3) CO2+ 8H + + 8e - → CH4+ 2H2O (4) 2H2O + 4h + → O2+ 4H + (5) In the gas-phase carbon dioxide reduction device, the aqueous solution in the reduction tank is removed and gas-phase carbon dioxide is filled in, but simply filling the tank with gas-phase carbon dioxide does not result in the generation of protons (H + ) cannot move in the gas phase, so it is necessary to join the electrolyte membrane and the reduction electrode. Furthermore, simply joining a plate-shaped reduction electrode to the electrolyte membrane does not allow the gas phase carbon dioxide to reach the interface between the reduction electrode and the electrolyte membrane, so a three-phase interface consisting of the reduction electrode / electrolyte membrane / gas phase carbon dioxide is required to supply carbon dioxide to the interface between the reduction electrode and the electrolyte membrane.

[0008] To create this three-phase interface, research has been conducted on electrode-supported electrolyte membranes, in which a porous reduction electrode and an electrolyte membrane are stacked and bonded together. During the carbon dioxide reduction reaction, such electrolyte membranes gradually swell due to the influence of the aqueous solution in the oxidation vessel that contacts the electrolyte membrane, causing the aqueous solution to permeate into the reduction electrode.

[0009] As a result, the surface of the porous reduction electrode, to which gaseous carbon dioxide should be supplied, is covered with the aqueous solution, resulting in a decrease in the period (lifespan) during which the porous reduction electrode and electrolyte membrane can maintain their carbon dioxide reduction performance.

[0010] The present invention has been made in view of the above, and aims to suppress seepage of an aqueous solution through an electrolyte membrane into a porous reduction electrode, thereby extending the period during which the porous reduction electrode and the electrolyte membrane can maintain their carbon dioxide reduction performance. [Means for solving the problem]

[0011] One aspect of the present invention is a porous electrode-supported electrolyte membrane used in a gas-phase reduction device that reduces carbon dioxide, the porous electrode-supported electrolyte membrane having an electrolyte membrane and a porous reduction electrode embedded in the electrolyte membrane, wherein a portion of the porous reduction electrode is exposed on a predetermined surface of the porous electrode-supported electrolyte membrane.

[0012] One aspect of the present invention is a method for manufacturing a porous electrode-supported electrolyte membrane used in a gas-phase reduction device that reduces carbon dioxide, the method comprising the steps of: impregnating a porous reduction electrode in an electrolyte membrane dispersion; drying the electrolyte membrane dispersion to produce an electrolyte membrane in which the porous reduction electrode is embedded; and scraping the surface of the electrolyte membrane to expose a portion of the porous reduction electrode. [Effects of the Invention]

[0013] According to the present invention, it is possible to suppress the seepage of an aqueous solution through an electrolyte membrane into a porous reduction electrode, thereby extending the period during which the porous reduction electrode and the electrolyte membrane can maintain their carbon dioxide reduction performance. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a cross-sectional view showing an example of the configuration of a porous electrode-supported electrolyte membrane according to this embodiment. [Figure 2] FIG. 2 is a flowchart showing an example of a method for producing a porous electrode-supported electrolyte membrane. [Figure 3] FIG. 3 is an explanatory diagram for explaining the step of scraping the surface of the porous electrode-supported electrolyte membrane. [Figure 4] FIG. 4 is a diagram showing an example of the configuration of a gas-phase carbon dioxide reduction device equipped with a porous electrode-supported electrolyte membrane. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The present invention is not limited to the embodiments described below, and modifications may be made without departing from the spirit of the present invention.

[0016] [Configuration of porous electrode-supported electrolyte membrane] The porous electrode-supported electrolyte membrane 20 of this embodiment will be described with reference to the cross-sectional view of Figure 1. The porous electrode-supported electrolyte membrane 20 of this embodiment includes an electrolyte membrane 6 and a porous reduction electrode 5 embedded in the electrolyte membrane 6.

[0017] The illustrated porous electrode-supported electrolyte membrane 20 has a porous reduction electrode 5 embedded inside an electrolyte membrane 6. A portion of the embedded porous reduction electrode 5 is exposed on a predetermined surface (one side) of the electrolyte membrane 6. The porous reduction electrode 5 is formed using a porous body (porous material) having a plurality of fine pores (air pores). The pores of the porous reduction electrode 5 include interconnected pores that allow carbon dioxide to pass through the porous reduction electrode 5 and reach the interface with the electrolyte membrane 6. The porous reduction electrode 5 may also include closed pores. The cross-sectional shape of the pores is not limited to the circle shown in FIG. 1 and may be various shapes. The porous reduction electrode 5 may also be made of a porous metal with a mesh structure.

[0018] As shown in the enlarged view 200 of Fig. 1, the pores of the porous reduction electrode 5 of this embodiment are filled with an electrolyte membrane 6. This forms a three-phase interface consisting of [electrolyte membrane - porous reduction electrode - gas-phase carbon dioxide]. Note that the porous reduction electrode 5 may include pores that are not filled with the electrolyte membrane 6, such as isolated pores.

[0019] The porous reduction electrode 5 does not need to be entirely exposed, but only needs to be partially exposed on a predetermined face (surface). The predetermined face of the porous electrode-supported electrolyte membrane 20 is placed in the gas-phase reduction device 100 so as to face the reduction tank 4 side of the gas-phase reduction device 100, which will be described later.

[0020] The porous reduction electrode 5 is an electrode using a porous body (porous material). For example, the porous reduction electrode 5 may be a porous body containing copper, platinum, gold, silver, indium, palladium, gallium, nickel, tin, cadmium, or an alloy thereof; a porous body containing silver oxide, copper oxide, copper(II) oxide, nickel oxide, indium oxide, tin oxide, tungsten oxide, tungsten(VI) oxide, copper oxide, or the like; or a porous body containing a porous metal complex having a metal ion and an anionic ligand.

[0021] For the electrolyte membrane 6, for example, Nafion (registered trademark), Forblue, Aquivion, or the like, which is a perfluorocarbon material having a skeleton made of carbon and fluorine, can be used.

[0022] [Method of manufacturing a porous electrode-supported electrolyte membrane] A method for manufacturing the porous electrode-supported electrolyte membrane 20 of this embodiment will be described with reference to the flowchart of FIG.

[0023] In step S1, the porous reduction electrode 5 is immersed in an electrolyte dispersion liquid.

[0024] In step S2, the electrolyte dispersion liquid in which the porous reduction electrode 5 is impregnated is dried to produce an electrolyte membrane 6 in which the porous reduction electrode 5 is embedded.

[0025] In step S3, one surface of the electrolyte membrane 6 in which the porous reduction electrode 5 is embedded is scraped to expose a part of the porous reduction electrode 5. Specifically, as shown in Fig. 3 , the surface of the electrolyte membrane 6 in which the porous reduction electrode 5 is embedded is cut to form a surface on which the porous reduction electrode 5 is exposed, thereby producing a porous electrode-supported electrolyte membrane 20.

[0026] Methods for scraping the surface of the electrolyte membrane 6 include polishing with an abrasive (sandpaper, grindstone, etc.), sandblasting, chemical etching, laser processing, and the like.

[0027] [Gas-phase reduction device (artificial photosynthesis)] Next, a gas-phase reduction device 100 for carbon dioxide will be described with reference to Fig. 4. The gas-phase reduction device 100 includes a porous electrode-supported electrolyte membrane 20 of this embodiment. The gas-phase reduction device 100 shown in Fig. 4 is a reduction device that uses artificial photosynthesis technology to reduce carbon dioxide by light irradiation.

[0028] The gas-phase reduction device 100 includes an oxidation vessel 1 and a reduction vessel 4 formed by dividing the internal space of a housing in two by a porous electrode-supported electrolyte membrane 20. That is, the porous electrode-supported electrolyte membrane 20 is disposed between the oxidation vessel 1 and the reduction vessel 4. The porous electrode-supported electrolyte membrane 20 is disposed with the surface on which the porous reduction electrode 5 is exposed facing the reduction vessel 4.

[0029] An oxidation vessel 1 is filled with an aqueous solution 3. An oxidation electrode 2 made of a semiconductor or a metal complex is inserted into the aqueous solution 3.

[0030] The oxidation electrode 2 can be made of a compound exhibiting photoactivity and redox activity, such as a nitride semiconductor, titanium oxide, amorphous silicon, a ruthenium complex, or a rhenium complex. The oxidation electrode 2 is electrically connected to the porous reduction electrode 5 by a conducting wire 7.

[0031] Examples of aqueous solution 3 that can be used include an aqueous potassium hydrogen carbonate solution, an aqueous sodium hydrogen carbonate solution, an aqueous potassium chloride solution, an aqueous sodium chloride solution, an aqueous sodium hydroxide solution, an aqueous potassium hydroxide solution, an aqueous rubidium hydroxide solution, and an aqueous cesium hydroxide solution. During the reduction reaction, helium gas is supplied to aqueous solution 3 through tube 8.

[0032] Carbon dioxide is supplied from a gas inlet 10 to the reduction tank 4, and the reduction tank 4 is filled with carbon dioxide or a gas containing carbon dioxide.

[0033] The light source 9 is disposed opposite the oxidation electrode 2 to drive the gas-phase reduction device 100. That is, the light source 9 is disposed so as to irradiate the oxidation electrode 2 with light. The light source 9 is, for example, a xenon lamp, a solar simulator, a halogen lamp, a mercury lamp, sunlight, or the like. The light source 9 may also be configured using a combination of these.

[0034] In FIG. 4, light energy is used as the energy for operating the gas phase reduction reaction apparatus 100, but the energy is not limited to this, and electrical energy, thermal energy, or renewable energy may also be used.

[0035] [Example of porous electrode-supported electrolyte membrane] Examples 1-4 were prepared as the porous electrode-supported electrolyte membrane 20 to be placed in the gas-phase reduction device 100, with the pore diameter of the porous reduction electrode 5 being varied, and a gas-phase reduction test, which will be described later, was carried out. The porous electrode-supported electrolyte membrane of Example 1-4 will now be described.

[0036] Example 1 In Example 1, a porous copper metal plate with a thickness of 0.2 mm, a pore diameter of 5 μm, and a porosity of 50% was used as the porous reduction electrode 5. A 5.0 wt % Nafion dispersion liquid manufactured by Sigma Aldrich was used as the electrolyte dispersion liquid.

[0037] A porous metal plate was formed into a predetermined size (30 mm x 30 mm) to prepare a porous reduction electrode 5. Then, this porous reduction electrode 5 was fitted into a rectangular parallelepiped mold (internal dimensions 30 mm x 30 mm x 1 mm).

[0038] In step S1, Nafion solution was added at a concentration of 460 μl / cm 3 so as to completely cover the porous reduction electrode 5. 2 As a result, the porous reduction electrode 5 was impregnated with the Nafion solution (electrolyte dispersion solution), and the pores of the porous reduction electrode 5 were filled with the electrolyte membrane 6.

[0039] In step S2, the rectangular parallelepiped with the porous reduction electrode 5 immersed in the Nafion solution was left to stand for 10 hours at 25°C under saturated vapor pressure of ethanol to dry the Nafion solution, thereby obtaining an electrolyte membrane 6 (Nafion membrane) with the porous reduction electrode 5 embedded therein.

[0040] In step S3, as shown in FIG. 3, one side of the electrolyte membrane 6 with the porous reduction electrode 5 embedded therein was scraped with sandpaper to expose the porous reduction electrode 5 on the surface, thereby producing a porous electrode-supported electrolyte membrane 20 as shown in FIG. 1.

[0041] <Example 2> In Example 2, a porous copper body having a thickness of 0.2 mm, a pore diameter of 10 μm, and a porosity of 50% was used as the porous reduction electrode 5. Other conditions were the same as in Example 1.

[0042] Example 3 In Example 3, a porous copper body having a thickness of 0.2 mm, a pore diameter of 50 μm, and a porosity of 50% was used as the porous reduction electrode 5. Other conditions were the same as in Example 1.

[0043] Example 4 In Example 4, a porous copper body having a thickness of 0.2 mm, a pore diameter of 500 μm, and a porosity of 50% was used as the porous reduction electrode 5. Other conditions were the same as in Example 1.

[0044] [Electrochemical measurements and gas and liquid production measurements] Each of the porous electrode-supported electrolyte membranes 20 of Examples 1 to 4 was attached to the gas-phase reduction device 100 of FIG. 4, and the following reduction reaction test was carried out.

[0045] The oxidation tank 1 was filled with the aqueous solution 3. The aqueous solution 3 was a 1.0 mol / L aqueous potassium hydroxide solution.

[0046] The oxidation electrode 2 was placed in the oxidation tank 1 so that it was submerged in the aqueous solution 3. A semiconductor photoelectrode prepared as follows was used for the oxidation electrode 2. A thin film of GaN, an n-type semiconductor, and AlGaN were epitaxially grown in this order on a sapphire substrate, and Ni was vacuum-deposited on the AlGaN, followed by heat treatment to form a NiO promoter thin film, thereby preparing a semiconductor photoelectrode.

[0047] The light source 9 is a 300W high-pressure xenon lamp (cutting wavelengths of 450nm or more, illuminance 6.6mW / cm 2 The light source 9 was fixed so that the surface of the oxidation electrode 2 on which the oxidation promoter was formed was the irradiated surface. The light irradiation area of ​​the oxidation electrode 2 was 3.6 cm 2 It was decided.

[0048] Helium (He) was fed into the oxidation vessel 1 through tube 8, and carbon dioxide (CO2) was fed into the reduction vessel 4 through gas inlet 10 at a flow rate of 5 ml / min. In this system, the reduction reaction of carbon dioxide can proceed at the three-phase interface consisting of [electrolyte membrane-copper-gas phase carbon dioxide] within the porous electrode-supported electrolyte membrane 20.

[0049] After the oxidation tank 1 and reduction tank 4 were thoroughly replaced with helium and carbon dioxide, light was uniformly irradiated onto the oxidation electrode 2 using a light source 9. Electrons flow between the oxidation electrode 2 and the porous reduction electrode 5 due to the light irradiation.

[0050] The current value between the oxidation electrode 2 and the porous reduction electrode 5 during light irradiation was measured using an electrochemical measurement device (Solartron, Model 1287 potentiogalvanostat). In addition, gas and liquid samples were collected from the oxidation tank 1 and the reduction tank 4 at any time during light irradiation, and the reaction products were analyzed using a gas chromatograph, a liquid chromatograph, and a gas chromatograph mass spectrometer. As a result, it was confirmed that oxygen was produced in the oxidation tank 1, and hydrogen, carbon monoxide, formic acid, methanol, and ethanol were produced in the reduction tank 4.

[0051] The test results of Examples 1-4 will be described later together with the test results of Comparative Example 1.

[0052] [Example of comparison] In Comparative Example 1, a porous electrode-supported electrolyte membrane was produced by thermocompression bonding an electrolyte membrane 6 and a porous reduction electrode 5. This Comparative Example 1 was placed as the porous electrode-supported electrolyte membrane 20 in the gas-phase reduction device 100 of FIG. 4, and tests similar to those in Examples 1-4 were performed.

[0053] <Comparative example 1> In Comparative Example 1, the porous reduction electrode 5 was a copper porous body having a thickness of 0.2 mm, a pore diameter of 500 μm, and a porosity of 50%, and the electrolyte membrane 6 was a Nafion proton exchange membrane.

[0054] The porous reduction electrode 5 was placed on top of the electrolyte membrane 6 and placed between two copper plates. This sample was then placed between a thermocompression bonding device (hot press) and thermocompression bonded by applying pressure perpendicular to the surface of the porous reduction electrode 5 at a heating temperature of 100°C, and left for 3 minutes. The sample was then quickly cooled and removed, yielding a porous electrode-supported electrolyte membrane in which the electrolyte membrane 6 and the porous reduction electrode 5 were bonded.

[0055] [Evaluation of Examples and Comparative Examples] Next, the test results for the Examples and Comparative Examples are described. Table 1 shows the Faraday efficiencies of the carbon dioxide reduction reaction after 1 hour and the Faraday efficiency maintenance rates of the carbon dioxide reduction reaction after 100 hours for Examples 1-4 and Comparative Example 1.

[0056] [Table 1]

[0057] As shown in formula (6), the Faraday efficiency indicates the ratio of the current value used in each reduction reaction to the current value that flows between the electrodes when irradiated with light or when a voltage is applied.

[0058] Faraday efficiency of each reduction reaction [%] = (charge consumed in each reduction reaction) / (charge flowing between the oxidation electrode and reduction electrode) × 100 (6) Here, the "charge consumed in each reduction reaction" in equation (6) can be calculated by converting the measured amount of reaction product for each reduction reaction into the charge required for that reduction reaction. When the amount of reaction product for each reduction reaction is A [mol], the number of electrons required for the reduction reaction is Z, and the Faraday constant is F [C / mol], the "charge consumed in each reduction reaction" can be calculated using equation (7).

[0059] Charge consumed in each reduction reaction [C] = A × Z × F (7) Further, the faradaic efficiency maintenance rate of each reduction reaction after 100 hours was defined and calculated according to the following formula (8).

[0060] Faraday efficiency maintenance rate [%] of each reduction reaction after 100 hours = (Faraday efficiency of each reduction reaction after 100 hours) / (Faraday efficiency of each reduction reaction after 1 hour) × 100 (8) The Faraday efficiency maintenance rate of the carbon dioxide reduction reaction after 100 hours is compared between Examples 1-4 and Comparative Example 1. The Faraday efficiency maintenance rate of the carbon dioxide reduction reaction after 100 hours was higher in the Examples than in the Comparative Example.

[0061] In Comparative Example 1, after 100 hours, liquid was collected from the exposed surface of the porous reduction electrode 5 and from inside the reduction tank 4 and analyzed for components. It was found that approximately 0.14 to 0.15 mL of the aqueous solution in the oxidation tank 1 had leaked out. This is thought to be due to swelling of the electrolyte membrane 6, as the porous reduction electrode 5 was not embedded in the electrolyte membrane 6.

[0062] In this case, the electrolyte membrane 6 becomes swollen due to excess moisture, and the aqueous solution in the oxidation vessel 1 permeates through the electrolyte membrane 6 into the reduction vessel 4. The aqueous solution then covers the surface of the porous reduction electrode 5, to which gaseous carbon dioxide should be supplied, and this is thought to have shortened the life of the carbon dioxide reduction reaction.

[0063] On the other hand, it was found that in Example 1-4, the seepage of the aqueous solution in the oxidation vessel 1 was suppressed to approximately 0.03 to 0.05 mL. This suggests that the structure in which the porous reduction electrode 5 is embedded in the electrolyte membrane 6 suppresses swelling of the electrolyte membrane 6, suppresses permeation of the aqueous solution, and improves the maintenance rate of the carbon dioxide reduction reaction.

[0064] From the above, by using a porous electrode-supported electrolyte membrane 20 having a structure in which the porous reduction electrode 5 is embedded in the electrolyte membrane 6 and the porous reduction electrode 5 is exposed on one side thereof, it is possible to suppress the seepage of the aqueous solution from the oxidation vessel 1 through the electrolyte membrane 6, and to improve the lifespan of the gas-phase reduction of carbon dioxide.

[0065] As described above, the porous electrode-supported electrolyte membrane 20 of this embodiment is used in a gas-phase reduction device that reduces carbon dioxide, and has an electrolyte membrane 6 and a porous reduction electrode 5 embedded in the electrolyte membrane 6, and a portion of the porous reduction electrode 5 is exposed on a predetermined surface of the porous electrode-supported electrolyte membrane 20.

[0066] Furthermore, the method for manufacturing a porous electrode-supported electrolyte membrane of this embodiment is used in a gas-phase reduction device that reduces carbon dioxide, and includes the steps of: impregnating a porous reduction electrode 5 in an electrolyte membrane dispersion (step S1); drying the electrolyte membrane dispersion to produce an electrolyte membrane 6 in which the porous reduction electrode 5 is embedded (step S2); and scraping the surface of the electrolyte membrane 6 to expose a portion of the porous reduction electrode 5 (step S3).

[0067] As a result, in this embodiment, it is possible to suppress the seepage of the aqueous solution in the oxidation vessel 1 through the electrolyte membrane 6, and it is possible to improve the life of the gas phase reduction reaction of carbon dioxide.

[0068] Specifically, the porous reduction electrode 5 is embedded in the electrolyte membrane 6, and the porous reduction electrode 5 acts as a template to suppress swelling of the electrolyte membrane 6. In this case, if the porous reduction electrode 5 is completely embedded in the electrolyte membrane 6, gas-phase carbon dioxide is not supplied to the surface of the porous reduction electrode 5, and the carbon dioxide reduction reaction does not proceed. Therefore, a porous electrode-supported electrolyte membrane 20 is fabricated in which the porous reduction electrode 5 is exposed on one side of the electrolyte membrane 6. The porous electrode-supported electrolyte membrane 20 is then placed in the gas-phase reduction device 100 with the exposed surface of the porous reduction electrode 5 facing the reduction tank 4. This suppresses expansion of the electrolyte membrane 6 due to the aqueous solution in the oxidation tank, and improves the life of the gas-phase reduction reaction of carbon dioxide.

[0069] The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the present invention. [Explanation of symbols]

[0070] 20:Porous electrode supported electrolyte membrane 5: Porous reduction electrode 6: Electrolyte membrane

Claims

1. A porous electrode-supported electrolyte membrane used in a gas-phase reduction device for reducing carbon dioxide, comprising: an electrolyte membrane; a porous reduction electrode embedded in the electrolyte membrane, a predetermined surface of the porous electrode-supported electrolyte membrane in which only a portion of the porous reduction electrode is exposed; At least some of the pores of the porous reduction electrode are filled with the electrolyte membrane. Porous electrode supported electrolyte membrane.

2. The gas-phase reduction device is arranged so that the predetermined surface faces the reduction tank side of the gas-phase reduction device. The porous electrode-supported electrolyte membrane according to claim 1 .

3. A method for producing a porous electrode-supported electrolyte membrane used in a gas-phase reduction device that reduces carbon dioxide, comprising: impregnating a porous reduction electrode with an electrolyte membrane dispersion; drying the electrolyte membrane dispersion to prepare an electrolyte membrane having the porous reduction electrode embedded therein; scraping the surface of the electrolyte membrane to expose a portion of the porous reduction electrode. A method for producing a porous electrode-supported electrolyte membrane.

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