Electrolysis equipment

Abstract

To provide an electrolytic device with excellent electrolysis efficiency. [Solution] According to the embodiment, an electrolytic device is provided comprising: a cathode for reducing a target to reduce and producing a reduction product; an anode for oxidizing a target to oxidize and producing an oxidation product; an electrolyte layer located between the cathode and the anode, containing at least one of the group consisting of a heat-resistant polymer, a solid acid, a solid salt, and a molten salt; and an electrolyte layer having a first ion-conducting material; and at least one of the two locations between the cathode and the electrolyte layer, or between the anode and the electrolyte layer, comprising: a porous material; and a control layer on which a second ion-conducting material is supported in at least a portion of the pores of the porous material; wherein the area of ​​the second ion-conducting material on the cathode side and / or anode side surface of the control layer is A, and the area on the electrolyte layer side surface of the control layer is B, such that 0 ≤ A ≤ B.

Description

[Technical Field]

[0001] Embodiments of the present invention relate to an electrolytic device. [Background technology]

[0002] In recent years, concerns about the depletion of fossil fuels such as oil and coal have led to increased expectations for sustainably usable renewable energy. From the perspective of such energy and environmental issues, development is progressing on power-to-chemical technology, which uses renewable energy sources such as solar power to electrochemically reduce carbon dioxide (CO2) and nitrogen (N2) to create a storable chemical energy source.

[0003] Electrolytic devices that realize power-to-chemical technology include, for example, an anode that oxidizes water (H2O) to produce oxygen (O2) and a cathode that reduces CO2 to produce carbon compounds such as carbon monoxide (CO), with an ion-conductive electrolyte layer placed between the cathode and the anode. When the material of the electrolyte layer leaches from the electrolyte layer to the electrodes, effects such as a reduction in the voltage required for the electrode reaction and an improvement in the selectivity of the target product can be obtained. On the other hand, if leaching occurs excessively, an increase in overpotential and side reactions become dominant, hindering the improvement of electrolysis efficiency. For example, this tendency is particularly pronounced when operating the electrolytic device in the temperature range of 100°C to 500°C. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. 2019 / 048016 [Overview of the project] [Problems that the invention aims to solve]

[0005] The problem that this invention aims to solve is to provide an electrolytic apparatus with excellent electrolytic efficiency. [Means for solving the problem]

[0006] According to the embodiment, an electrolytic device is provided comprising: a cathode for reducing a target to reduce and producing a reduction product; an anode for oxidizing a target to oxidize and producing an oxidation product; an electrolyte layer located between the cathode and the anode, containing at least one of the group consisting of a heat-resistant polymer, a solid acid, a solid salt, and a molten salt; and an electrolyte layer having a first ion-conducting material; and at least one of the two locations between the cathode and the electrolyte layer, or between the anode and the electrolyte layer, comprising: a porous material; and a control layer on which a second ion-conducting material is supported in at least a portion of the pores of the porous material; wherein the area of ​​the second ion-conducting material on the cathode side and / or anode side surface of the control layer is A, and the area on the electrolyte layer side surface of the control layer is B, such that 0 ≤ A ≤ B. [Brief explanation of the drawing]

[0007] [Figure 1] A cross-sectional view showing an example of the configuration of an electrolytic apparatus according to the embodiment. [Figure 2] A schematic diagram showing a portion of the configuration of the electrolytic apparatus according to the embodiment. [Figure 3] A schematic diagram showing a portion of the configuration of the electrolytic apparatus according to the embodiment. [Figure 4] Cross-sectional view of the electrolyte layer and control layer relating to the function of the control layer. [Figure 5] A cross-sectional view showing a modified configuration of the electrolytic apparatus according to the embodiment. [Figure 6] A schematic diagram showing a portion of the configuration of the electrolytic apparatus according to the embodiment. [Modes for carrying out the invention]

[0008] Hereinafter, embodiments will be described with reference to the drawings. In the following description, components that exhibit the same or similar functions are given the same reference numerals throughout all the drawings, and redundant descriptions are omitted. Also, each drawing is a schematic diagram for facilitating the description and understanding of the embodiments, and there are differences in its shape, dimensions, ratios, etc. from the actual device, but these can be appropriately designed and changed in consideration of the following description and known techniques.

[0009] In this specification, the cathode and anode may be collectively referred to as electrodes. Also, the cathode catalyst and anode catalyst may be collectively referred to as electrode catalysts. Further, the supply fluid and discharge fluid may be collectively referred to as fluids.

[0010] In the electrolyzer according to the embodiment, when the electrolyte containing an ion-conductive material leaches into the electrodes, an ion conduction path, an electron conduction path, and a movement path for reactants and products are simultaneously ensured within the electrodes, forming a good reaction field, and the main reaction at the electrodes, for example, the reduction reaction of carbon dioxide proceeds at the cathode. If the leaching of the electrolyte is excessive, side reactions at the electrodes, for example, the generation of hydrogen becomes dominant at the cathode and the electrolysis efficiency is poor. Therefore, in the present invention, by adjusting the leaching of the electrolyte to an appropriate amount, an electrolyzer with excellent electrolysis efficiency is provided. Hereinafter, leaching refers to leaching from the electrolyte.

[0011] (First Embodiment) According to an embodiment, an electrolysis device according to the embodiment includes a cathode for reducing a reduction target to generate a reduction product, an anode for oxidizing an oxidation target to generate an oxidation product, an electrolyte layer material disposed between the cathode and the anode and containing at least one of a heat-resistant polymer, a solid acid, a solid acid salt, and a molten salt, and an electrolyte layer having a first ion-conductive material. At least one of between the cathode and the electrolyte layer or between the anode and the electrolyte layer includes a porous material and a control layer in which a second ion-conductive material is supported on at least a part of pores of the porous material. When the area of the second ion-conductive material on the surface of the cathode side or / and the anode side of the control layer is A, and the area on the surface of the electrolyte layer side of the control layer is B, 0 ≦ A ≦ B.

[0012] This will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing an example of the configuration of an electrolysis device according to an embodiment. In the embodiment, the electrolysis device 1 has an electrolysis unit 10. The electrolysis unit 10 has an electrolytic cell 20. The electrolytic cell 20 has an electrolyte layer 30, a control layer 40, a cathode section 50, and an anode section 60. The cathode section 50 has a cathode 51, a cathode flow path 52, a cathode flow path plate 53, and a cathode current collector plate 54. The cathode supply fluid 55 contains a reduction target and is connected via an inlet (not shown) so as to be supplied to the cathode flow path 52. The cathode discharge fluid 56 contains a reduction product and is connected via an outlet (not shown) so as to be discharged from the cathode flow path 52. The anode section 60 has an anode 61, an anode flow path 62, an anode flow path plate 63, and an anode current collector plate 64. The anode supply fluid 65 contains an oxidation target and is connected via an inlet (not shown) so as to be supplied to the anode flow path 62. The anode discharge fluid 66 contains an oxidation product and is connected via an outlet (not shown) so as to be discharged from the anode flow path 62. The electrolysis device 1 may further include a power source 70. The power source 70 is electrically connected to the cathode current collector plate 54 of the cathode section 50 and the anode current collector plate 64 of the anode section 60.

[0013] The electrolyte layer 30, cathode 51, anode 61, and control layer 40 may be stacked to form a membrane electrode assembly. The electrolyte layer 30, cathode 51, anode 61, and control layer 40 may be further stacked together with other components to form an electrolytic cell 20.

[0014] The cathode section 50, anode section 60, electrolyte layer 30, control layer 40, and power supply 70 will be described below.

[0015] (Cathode section) The cathode 51 has a first surface in contact with the cathode channel 52 and the cathode channel plate 53, and a second surface on the opposite side of the first surface in contact with the control layer 40. The cathode 51 is a reduction electrode for carrying out a reduction reaction of at least one substance to be reduced to produce reduction products. Examples of substances to be reduced are carbon dioxide and nitrogen. Reduction products are compounds after the reduction reaction of the substance to be reduced, such as carbon compounds and nitrogen compounds. The cathode 51 reduces carbon dioxide to produce carbon compounds, or reduces nitrogen to produce nitrogen compounds. Examples of carbon compounds include carbon monoxide, formic acid, methanol, methane, ethanol, ethane, ethylene, formaldehyde, ethylene glycol, acetic acid, and propanol. Examples of nitrogen compounds include ammonia and hydrazine. The cathode 51 can also simultaneously reduce carbon dioxide and nitrogen to produce urea, etc. Along with the reduction reaction of carbon dioxide and nitrogen, the cathode 51 may produce a side reaction in which hydrogen is generated by the reduction reaction of water.

[0016] The cathode 51 is preferably shaped to allow the movement of ions and water between the electrolyte layer 30 and the cathode channel 52. The cathode 51 can be made of various shapes, such as a plate, mesh, wire, punched, particulate, porous, thin film, or island, or it can be made of a sintered metal fiber. The material of the cathode 51 can be the same as the material of the cathode catalyst layer described later.

[0017] The cathode 51, although not shown, may have a cathode catalyst layer and a gas diffusion layer. Preferably, the cathode catalyst layer is located on the electrolyte layer 30 side, and the gas diffusion layer is located on the cathode flow channel plate 53 side. The cathode catalyst layer may be embedded within the gas diffusion layer. The cathode 51 may also have a porous layer between the gas diffusion layer and the cathode catalyst layer that is denser than the gas diffusion layer. The presence of a cathode catalyst layer and / or a gas diffusion layer in the cathode 51 promotes the supply of the cathode supply fluid 55 to the cathode 51, thereby improving the reaction rate of the reduction reaction.

[0018] The cathode catalyst layer contains a cathode catalyst that promotes the reduction reaction that reduces the target substance. The cathode catalyst layer is formed using a material that reduces the activation energy required to reduce the target substance. In other words, the cathode catalyst layer is formed using a material that lowers the overpotential when reduction products are generated by the reduction reaction of the target substance. The cathode catalyst layer can be made of metals such as gold (Au), silver (Ag), copper (Cu), platinum (Pt), palladium (Pd), nickel (Ni), cobalt (Co), iron (Fe), manganese (Mn), titanium (Ti), cadmium (Cd), zinc (Zn), indium (In), gallium (Ga), lead (Pb), tin (Sn), or metallic materials such as alloys or intermetallic compounds containing at least one of these metals. The cathode catalyst layer can also be made of carbon materials such as carbon (C), graphene, CNT (carbon nanotube), fullerene, and Ketjenblack, or metal complexes such as ruthenium (Ru) complexes and rhenium (Re) complexes. To enhance the reduction reaction, the cathode catalyst layer preferably has the shape of nanoparticles, nanostructures, or nanowires. A nanostructure is a structure in which nanoscale irregularities are formed on the surface of the catalyst material.

[0019] The gas diffusion layer diffuses the cathode supply fluid 55 so that it is uniformly supplied from the cathode channel 52 to the cathode catalyst layer. The gas diffusion layer also plays a role in discharging the products of the reduction reaction generated in the cathode catalyst layer and in conducting electrons. The gas diffusion layer is made of, for example, carbon paper or carbon cloth with excellent electron conductivity and is treated with a water-repellent coating. The water-repellent properties of the gas diffusion layer suppress the accumulation of moisture and maintain the activity of the cathode 51.

[0020] In the gas diffusion layer, cathode supply fluid 55 is supplied from the cathode channel 52, and reduction products are discharged. The reduction reaction occurs near the boundary between the gas diffusion layer and the cathode catalyst layer, and the reduction products are discharged outside the electrolytic unit 10 through the cathode channel 52 via the gas diffusion layer.

[0021] The cathode channel plate 53 has a first surface in contact with the cathode current collector plate 54 and a second surface on the opposite side of the first surface in contact with the cathode 51. The cathode channel plate 53 forms a cathode channel 52 through which the cathode supply fluid 55 is reduced at the cathode 51. Figure 2 is a view of the cathode channel plate 53 in the electrolytic device 1 from the stacking direction. The cathode channel 52 and cathode channel plate 53 in Figure 1 represent cross-sections when cut along the dashed line A-A' in Figure 2. Figure 3 is a diagram of the cathode channel plate 53 extracted from the electrolytic device, showing the cathode channel plate 53 in three dimensions. Figure 3 shows the cathode channel plate 53 on an enlarged scale for easier understanding. The arrows in Figures 2 and 3 indicate the main movement path of the fluid as it moves through the cathode channel 52. The cathode channel plate 53 has a cathode channel 52 through which the cathode supply fluid 55 and cathode discharge fluid 56 pass, an inlet 102 for supplying the cathode supply fluid 55 to the cathode channel 52, and an outlet 103 for discharging the cathode discharge fluid 56 from the cathode channel 52. The shapes of the cathode channel 52 and the cathode channel plate 53 will be described in conjunction with Figure 1. The cathode channel 52 is a space (also called a groove or pit) created by processing the cathode channel plate 53. The cathode channel plate 53 has irregularities with respect to the stacking direction of the electrolytic device 1. In Figure 2, the cathode channel 52 is recessed toward the back of the paper. The inlet 102 and outlet 103 may be connected to other components via piping or the like.

[0022] The cathode channel 52 is positioned so that the substance to be reduced can react with ions and electrons at the cathode 51. It is desirable to ensure that the cathode channel 52 is long enough to carry out the reduction reaction efficiently. The cathode channel plate 53 can be provided with lands 101, for example, as shown in Figure 2. The lands 101 are provided for mechanical retention and electrical conductivity. It is desirable that the lands 101 be arranged alternately to homogenize the fluid flow. As a result, the cathode supply fluid 55 supplied from the inlet 102 passes through the cathode channel 52 in a meandering manner, and the cathode discharge fluid 56 is discharged from the outlet 103. The cathode channel 52 only needs to be positioned so that the substance to be reduced is in contact with the cathode 51; for example, the cathode 51 may be placed inside the cathode channel 52. The cathode supply fluid 55 and the cathode discharge fluid 56 may flow outside the cathode channel 52. The fluid may move from, for example, one portion of the cathode channel 52 that is in contact with the cathode 51 to the cathode 51, pass through the portion of the cathode 51 that is in contact with the land 101, and then flow to another portion of the cathode 51 that is in contact with the cathode channel 52. In this way, a fluid flow is generated that shortcuts the meandering channel through the porous structure of the cathode 51 that is in contact with the land 101, thereby effectively utilizing the cathode catalyst in the portion of the cathode 51 that is in contact with the land 101.

[0023] The cathode channel plate 53 is formed using a material with low chemical reactivity and high conductivity. Examples of such materials include metallic materials such as titanium and SUS (stainless steel), and carbon materials. A packing or other component, not shown in the illustration, may be inserted between the cathode channel plate 53 and adjacent components as needed.

[0024] The cathode supply fluid 55 is a fluid containing the substance to be reduced and is supplied to the cathode channel 52. The cathode supply fluid 55 reacts with water, ions, or electrons in the cathode 51 after passing through the cathode channel 52, thereby changing the composition of the substance to be reduced. It is preferable that the cathode supply fluid 55 exists as a gas at the temperature and pressure inside the cathode channel 52. In other words, when operating the electrolytic device 1, it is preferable to adjust the temperature and pressure inside the cathode channel 52 so that the cathode supply fluid 55 exists as a gas.

[0025] The cathode discharge fluid 56 is a fluid containing reduction products and is discharged from the cathode channel 52. The cathode discharge fluid 56 contains reduction products, which are compounds resulting from the reaction of the substances to be reduced. In other words, a portion of the substances to be reduced is converted into reduction products in the cathode channel 52. The reduction products in the cathode discharge fluid 56 are separated and recovered as needed. As a method of separation and recovery, for example, the cathode discharge fluid 56 can be separated into gas and liquid phases, and a portion of the gas phase can be joined to the cathode supply fluid 55. This method is particularly effective when the cathode discharge fluid 56 contains unreacted substances to be reduced, and it is possible to increase the conversion rate of the substances to be reduced. Alternatively, the cathode discharge fluid 56 can be separated into gas and liquid phases, and a portion or all of the liquid phase can be joined to the anode supply fluid 65.

[0026] The selectivity of the reduction reaction in cathode 51 can change depending on the acidity and basicity of the reaction site vicinity. For example, to suppress hydrogen production and selectively promote the reduction of carbon dioxide, it is preferable that the reaction site vicinity be in a basic environment. However, since many ionic conductors are acidic, if the electrolyte layer 30 contains ionic conductors, the cathode from which components of the electrolyte layer 30 leach out may also become an acidic environment, which may hinder the progress of the reduction reaction of carbon dioxide. To address this, a basic compound can be included in cathode 51. Examples of basic compounds include, but are not limited to, alkali metal salts or alkaline earth metal salts. By including a basic compound in cathode 51, it is possible to locally suppress acidity and increase basicity near the cathode reaction site, thereby promoting the reduction reaction of carbon dioxide. Methods for including a basic compound in cathode 51 include, but are not limited to, mixing the basic compound with the raw materials when preparing the cathode catalyst layer, or impregnating the cathode catalyst layer with a solution containing the basic compound after preparation.

[0027] (Anode) The anode 61 has a first surface in contact with the anode channel 62 and the anode channel plate 63, and a second surface on the opposite side of the first surface in contact with the control layer 40. The anode 61 is an oxidation electrode for carrying out an oxidation reaction of at least one oxidizing agent (substance to be oxidized) to produce oxidation products. The oxidizing agent is a hydrogen-containing compound. Examples of hydrogen-containing compounds include water, ammonia, and methane. The anode 61 oxidizes water, for example, to produce oxygen and hydrogen ions (protons: H + ) generates.

[0028] The anode 61 is preferably shaped to allow the movement of ions and water between the electrolyte layer 30 and the anode channel 62. The anode 61 can be shaped in various ways, such as mesh, wire, perforated, particulate, porous, thin film, or island, or it can be made of a sintered metal fiber.

[0029] The material for the anode 61 can be a metal such as titanium (Ti), iron (Fe), or an alloy containing at least one of these metals (e.g., SUS). The material for the anode 61 can be the material for the anode catalyst layer described later.

[0030] The anode 61, although not shown, may have an anode catalyst layer and a gas diffusion layer. Preferably, the anode catalyst layer is located on the electrolyte layer 30 side, and the gas diffusion layer is located on the anode flow channel plate 63 side. The anode catalyst layer may be embedded within the gas diffusion layer. The anode 61 may also have a porous layer between the gas diffusion layer and the anode catalyst layer that is denser than the gas diffusion layer. By having an anode catalyst layer or a gas diffusion layer in the anode 61, the supply of the anode supply fluid 65 is promoted, and the reaction rate of the oxidation reaction can be improved.

[0031] The anode catalyst layer contains an anode catalyst that promotes the oxidation reaction that oxidizes the target substance. The anode catalyst layer is formed using a material that reduces the activation energy required to oxidize the target substance. In other words, the anode catalyst layer is formed using a material that reduces the overpotential generated when oxidation products are produced by the oxidation reaction of the target substance. The anode catalyst layer can be made of metals such as platinum (Pt), palladium (Pd), iridium (Ir), nickel (Ni), or alloys or intermetallic compounds containing at least one of these metals. The anode catalyst layer can be made of binary metal oxides such as manganese oxide (Mn-O), iridium oxide (Ir-O), nickel oxide (Ni-O), cobalt oxide (Co-O), iron oxide (Fe-O), tin oxide (Sn-O), indium oxide (In-O), ruthenium oxide (Ru-O), lithium oxide (Li-O), and lanthanum oxide (La-O), or ternary metal oxides such as Ni-Co-O, Ni-Fe-O, La-Co-O, Ni-La-O, and Sr-Fe-O, or quaternary metal oxides such as Pb-Ru-Ir-O and La-Sr-Co-O, or metal complexes such as Ru complexes and Fe complexes. The anode catalyst layer preferably has the shape of nanoparticles, nanostructures, or nanowires to enhance the oxidation reaction. When an oxide is used as the anode catalyst layer, it is preferable to form the anode catalyst layer by attaching or laminating the oxide on the surface of a substrate made of the above-mentioned metal material.

[0032] The gas diffusion layer is the same as the gas diffusion layer in cathode 51 described above.

[0033] The anode channel plate 63 has a first surface that contacts the anode current collector plate 64 and a second surface that is opposite the first surface and contacts the anode 61. The anode channel plate 63 forms an anode channel 62 in which the anode supply fluid 65 is oxidized at the anode 61. Since the anode channel plate 63 has the same shape and material as the cathode channel plate 53, the cathode channel 52 and cathode channel plate 53 in Figures 2 and 3 will be described by substituting them with the anode channel 62 and anode channel plate 63. Furthermore, descriptions common to both the anode channel plate 63 and the cathode channel plate 53 will be omitted.

[0034] The anode channel 62 is positioned so that the substance to be oxidized is oxidized at the anode 61. It is desirable to ensure that the anode channel 62 is long enough to allow the oxidation reaction to proceed efficiently. The anode channel 62 only needs to be positioned so that the substance to be oxidized is in contact with the anode 61; for example, the anode 61 may be located within the anode channel 62.

[0035] The anode supply fluid 65 is a fluid containing the substance to be oxidized and is supplied to the anode channel 62. The anode supply fluid 65 reacts with the anode 61 via the anode channel 62, thereby changing the composition of the substance to be oxidized. It is preferable that the anode supply fluid 65 exists as a gas at the temperature and pressure within the anode channel 62. In other words, when operating the electrolytic device 1, it is preferable to adjust the temperature and pressure within the anode channel 62 so that the anode supply fluid 65 exists as a gas.

[0036] The anode discharge fluid 66 is a fluid containing oxidation products and is discharged from the anode channel 62. The anode discharge fluid 66 contains oxidation products, which are compounds resulting from the reaction of the substance to be oxidized. In other words, a portion of the substance to be oxidized is transformed into oxidation products in the anode channel 62. The oxidation products in the anode discharge fluid 66 are separated and recovered as needed. As a method of separation and recovery, for example, the anode discharge fluid 66 may be separated into gas and liquid phases, and part or all of the liquid phase may be joined to the anode supply fluid 65. In particular, the amount of water used can be reduced by cooling the anode discharge fluid 66 to recover the liquid water and joining it to the anode supply fluid 65.

[0037] The cathode current collector plate 54 is laminated on the first surface of the cathode flow channel plate 53 and electrically connected. The anode current collector plate 64 is laminated on the first surface of the anode flow channel plate 63 and electrically connected. The cathode current collector plate 54 and the anode current collector plate 64 are electrically connected to the power supply 70. It is preferable that the cathode current collector plate 54 and the anode current collector plate 64 be formed using a material with high conductivity.

[0038] The electrolytic cell 20 is sandwiched between a pair of support plates (not shown) and further secured with bolts or the like. The electrolytic cell 20 may be arranged so that each stacked component is horizontal, or it may be arranged so that it is vertical. When each stacked component is horizontal, it does not matter whether the cathode 51 or the anode 61 is on top.

[0039] (electrolyte layer) The electrolyte layer 30 is located between the cathode 51 and the anode 61 and conducts ions. The electrolyte layer 30 has a first surface that contacts the control layer 40 on the cathode 51 side, and a second surface that is on the opposite side of the first surface and contacts the control layer 40 on the anode 61 side. The electrolyte layer 30 comprises an electrolyte layer material and a first ion-conducting material.

[0040] The electrolyte layer material is a material contained in the electrolyte layer 30, and the first ion-conducting material is an ion-conducting material present in the electrolyte layer 30. The electrolyte layer material is at least one of a heat-resistant polymer, a solid acid, a solid salt, and a molten salt. The first ion-conducting material is one of a solid acid, a solid salt, a molten salt, a liquid acid, an ionic liquid, and an ion-conducting polymer. The electrolyte layer material may be an ion-conducting material or a non-ion-conducting material. Therefore, the electrolyte layer material contained in the electrolyte layer 30 may be the same material as the first ion-conducting material or may be different. Multiple of the above materials may be used for the electrolyte layer material and the first ion-conducting material, or one of them may be used alone.

[0041] Next, the materials that may be included in the electrolyte layer 30 will be described. The heat-resistant polymer is, for example, in the form of a film. Hereafter, the heat-resistant polymer will be described as a film, or a heat-resistant polymer film. Examples of polymers that constitute a heat-resistant polymer film include, but are not limited to, polybenzimidazole (PBI), perfluorosulfonic acid (PFSA), polytetrafluoroethylene (PTFE), ethylene-tetrafluoroethylene copolymer (ETFE), and sulfurized polyetherketone. These polymers may or may not have ionic conductivity. The function of the heat-resistant polymer film can be enhanced by adding substances other than polymers. For example, ionic conductivity can be imparted to a non-ionic conductive heat-resistant polymer film, the ionic conductivity of an ionic conductive heat-resistant polymer film can be enhanced, or the heat resistance of the heat-resistant polymer film can be enhanced. Liquid acids, solid acids, and solid salts described later can be added to the heat-resistant polymer film to impart or enhance ionic conductivity. To enhance heat resistance, oxides such as silicon dioxide, zirconium oxide, and titanium oxide can be added to the heat-resistant polymer film. Methods for adding such functional materials to the heat-resistant polymer film include, for example, mixing the substance to be added or its precursor with the raw material of the heat-resistant polymer before forming the film, or adding the functional material or its precursor after the heat-resistant polymer film has been formed by impregnation or drying.

[0042] Solid acids and solid salts exist as solids at room temperature and pressure. During operation of an electrolytic device, solid acids and solid salts may undergo a phase change compared to their state at room temperature and pressure. Examples of solid acids and solid salts include oxo salts, pyrophosphates, and heteropoly acids. For example, oxo salts have the compositional formula M x H y (AO4) zIt is represented by M. M is lithium (Li), sodium (Na), potassium (K), cesium (Cs), rubidium (Rb), ammonium (NH4), etc., and M may have defects. A is an element such as sulfur (S), selenium (Se), arsenic (As), phosphorus (P), etc. The pyrophosphate is represented by, for example, the composition formula MP2O7. M is silicon (Si), zirconium (Zr), tin (Sn), titanium (Ti), germanium (Ge), cerium (Ce), tungsten (W), etc., and M may have defects. Also, M may be doped with other elements. Examples of the elements to be doped include indium (In), aluminum (Al), antimony (Sb), scandium (Sc), ytterbium (Yb), gallium (Ga), zinc (Zn), magnesium (Mg), manganese (Mn), etc. Another example of the pyrophosphate is the composition formula A 0.5 B 0.5 P2O7. A is a trivalent metal, and indium (In), aluminum (Al), antimony (Sb), gallium (Ga), iron (Fe), yttrium (Y), bismuth (Bi), samarium (Sm), etc. are applicable. B is a pentavalent metal, and antimony (Sb), niobium (Nb), tantalum (Ta), etc. are applicable. The heteropoly acid is represented by, for example, the composition formula H x AM 12 O 40 . A is phosphorus (P), silicon (Si), etc., and M is tungsten (W), molybdenum (Mo), etc.

[0043] The molten salt is an alkali molten salt or a molten carbonate. The alkali molten salt is, for example, sodium hydroxide or potassium hydroxide. The molten carbonate is, for example, lithium carbonate or sodium carbonate. The alkali molten salt and the molten carbonate may be used by mixing them with each molten salt.

[0044] The liquid acid exists as a liquid at normal temperature and pressure. The liquid acid is, for example, phosphoric acid.

[0045] For the ionic liquid and the ion-conductive polymer, those of ion-conductive materials can be used.

[0046] The first ion-conducting material may be mixed with the matrix material. The matrix material is a material used to increase the mechanical strength of the electrolyte layer, and the matrix material may or may not have ion conductivity. Examples of matrix materials include, but are not limited to, polymers, oxides such as silicon dioxide and zirconium oxide, and pyrophosphates such as silica pyrophosphate. The matrix material can take the form of, for example, a film, powder, or porous material.

[0047] The aforementioned example of adding solid acids, solid acid salts, or liquid acids to a heat-resistant polymer film can be interpreted as the heat-resistant polymer film functioning as a matrix material for the ion-conducting materials, namely the solid acid, solid acid salt, and liquid acid. While the matrix material contributes to increasing the mechanical strength of the electrolyte layer, it can also provide other functions. For example, it is known that a reaction occurs at the interface between the solid acid salt and the matrix material, creating a new ion-conducting layer that can result in ion conductivity exceeding that of the original solid acid salt.

[0048] Heat-resistant polymer films, solid acids, and solid salts typically exhibit high ionic conductivity in the temperature range of 100°C to 500°C. Therefore, an electrolytic device 1 using a heat-resistant polymer film, solid acid, or solid salt in the electrolyte layer 30 is preferably used in the temperature range of 100°C to 500°C. The desirable temperature range varies depending on the material, but for heat-resistant polymer films, a temperature range of 120°C to 200°C is preferred. For solid acids and solid salts, a temperature range of 150°C to 350°C is preferred. In actual operation, the electrolyte layer 30 can be controlled to a predetermined temperature by heating or cooling the electrolytic unit 10 of the electrolytic device 1. For temperature control, it is desirable to equip the electrolytic unit 10 with a heater, electric furnace, constant temperature bath, heat exchanger, etc.

[0049] Furthermore, operating the electrolytic device 1 in the temperature range of 100°C to 500°C has the effect of producing a variety of products at high reaction rates. Generally, the reactivity of the substance to be reduced increases with higher operating temperatures, but at high temperatures exceeding 500°C, the formation of reduction products such as alcohols, aldehydes, carboxylic acids, and other oxygen-containing compounds, as well as hydrocarbons with two or more carbon atoms and ammonia, becomes thermodynamically difficult. The temperature range of 100°C to 500°C is suitable for obtaining a variety of reduction products while increasing the reactivity of the substance to be reduced. In addition, it is known that most of the waste heat generated in the industrial field is below 300°C, and when operating the electrolytic device 1, especially in the temperature range of 100°C to 300°C, it is possible to reduce energy consumption by utilizing this waste heat. For this reason, among the materials that can be included in the electrolyte layer 30, heat-resistant polymer films, solid acids, and solid salts are desirable in that they exhibit characteristic effects in the above-mentioned temperature range. Solid acids and solid salts are even more desirable.

[0050] Some of the materials contained in the electrolyte layer 30 exist as a liquid during the operation of the electrolytic device 1. An example is phosphoric acid impregnated in a heat-resistant polymer film. In addition, many solid acids and solid salts remain in a solid state under the temperature and pressure conditions in which they act as ion conductors, but low-melting-point substances may be newly generated at the interface with the matrix material, and these may exist as a liquid. For example, when cesium dihydrogen phosphate, which is an ion conductor, is mixed with silica pyrophosphate as the matrix material, cesium pentahydrogen diphosphate may be generated at the interface between the two in the electrolyte layer 30 as a component derived from the solid acid. However, since the melting point of cesium pentahydrogen diphosphate is around 150°C, cesium pentahydrogen diphosphate exists as a liquid depending on the operating conditions of the electrolytic device 1.

[0051] Components present in the electrolyte layer 30 may partially seep into the cathode 51 or anode 61 due to driving forces such as capillary action, electrophoresis, or convection caused by pressure differences. Furthermore, water vapor in the cathode supply fluid 55 and anode supply fluid 65 may condense in the cathode 51 and anode 61, respectively, forming liquid water, into which liquid acids, solid acids, solid salts, etc., may dissolve. Condensation of water vapor is particularly likely to occur if the cathode 51 or anode 61 has a porous structure.

[0052] Components that leach from the electrolyte layer 30 to the electrode often possess ionic conductivity. Therefore, the leaching of components from the electrolyte layer 30 to the electrode increases the contact area between the electrode catalyst and the ionic conductor, thereby increasing the number of reaction sites contributing to the catalytic reaction. This can lead to a reduction in the voltage required for the electrode reaction and an improvement in the selectivity of the reduction product. On the other hand, if excessive leaching of components to the electrode occurs, the pore structure in the electrode may be blocked by the components, or the catalyst surface may be covered with the leached components, causing it to lose its function as a reaction active site. As a result, problems such as increased overpotential due to inhibited gas diffusion and decreased catalytic reaction activity may occur. These are undesirable because they lead to an increase in the power required by the electrolytic device 1 and a decrease in the selectivity of the reduction product. Therefore, there is a desirable range for the degree to which some of the components of the electrolyte layer 30 leach to the electrode, and it is desirable to appropriately control this range so that it remains within the desirable range. The desirable range varies depending on the material and shape of the electrolyte layer 30 and electrode used, the operating conditions of the electrolytic unit 10, etc.

[0053] (Control layer) The control layer 40 is provided between the electrolyte layer 30 and the cathode 51 of the electrolytic unit 10, or between the electrolyte layer 30 and the anode 61, or both. Preferably, the control layer 40 is located at least between the electrolyte layer 30 and the cathode 51 of the electrolytic unit 10. The control layer 40 comprises a porous material and a second ion conductive material. The role of the control layer 40 is to control the amount of electrolyte layer components that leach into the cathode 51 or anode 61. By using an appropriate control layer 40, it is possible to adjust the degree to which components of the electrolyte layer 30 move to the electrodes to a desirable range.

[0054] Porous materials have pores. These pores may be distributed in the thickness direction of the porous material. Porous materials are, for example, non-ionic conductive materials. As will be discussed later, porous materials may contain ionic conductive materials in part.

[0055] The second ion-conducting material is an ion-conducting material present in the control layer 40. The second ion-conducting material is one of the following materials: a solid acid, a solid salt, a molten salt, a liquid acid, an ionic liquid, or an ion-conducting polymer. The second ion-conducting material may contain one or more first ion-conducting materials. The second ion-conducting material is supported in at least some of the pores of the porous material, extending from the electrolyte layer 30 toward the electrode. The presence of the second ion-conducting material in the pores of the porous material forms an ion conduction path from the electrolyte layer 30 toward the electrode.

[0056] The first ion-conducting material and the second ion-conducting material can be materials with different ion conductivity. In other words, the second ion-conducting material can be a material with an ion conductivity other than the material selected for the first ion-conducting material. As an example, consider the case where the first ion-conducting material is a solid acid. By impregnating a porous material of non-ion-conducting material with liquid acid, the control layer 40 becomes ion-conductive. In this case, even if leaching from the electrolyte layer 30 to the control layer 40 does not occur, a path for ions to move from the electrolyte layer 30 to the electrode is provided. Also, in this case, the second ion-conducting material is a liquid acid, which is a different material from the first ion-conducting material.

[0057] A portion of the porous material may be an ion-conducting material. The control layer 40 does not need to exhibit ion conductivity when the electrolytic device 1 is not in operation, but it should be ion-conductive when the electrolytic device 1 is in operation and provide a path for ions to move between the electrolyte layer 30 and the electrodes. The porous material may be entirely an ion-conducting material.

[0058] As described above, the control layer 40 does not need to exhibit ionic conductivity when the electrolytic device 1 is not in operation. However, during operation of the electrolytic device 1, the control layer 40 needs to exhibit ionic conductivity and provide a pathway for ions to move between the electrolyte layer 30 and the electrodes. If the porous material does not contain ionic conductive material during the manufacturing stage of the electrolytic device 1, the control layer 40 needs to acquire ionic conductivity as a result of pre-operation treatment or the operation itself. Specifically, the control layer 40 can exhibit ionic conductivity by allowing components containing ionic conductive material to leach from the electrolyte layer 30 into the pores of the porous material of the control layer 40. On the other hand, if only components from the electrolyte layer 30 leach out, the ionic conductivity of the control layer 40 during operation of the electrolytic device 1 may be insufficient or non-uniform. Therefore, an ionic conductor may be included in the control layer 40 during the manufacturing stage of the electrolytic device 1.

[0059] By altering the properties of the porous material, it is possible to adjust the degree to which the components of the electrolyte layer 30 move to the electrodes. Here, we will explain the porosity and pore diameter of the porous material.

[0060] The porosity of porous materials should ideally be between 20% and 80%. This allows an appropriate amount of secondary ion-conducting material to be retained within the pores. If the porosity is less than 20%, sufficient ion conduction pathways to the electrodes will not be formed. Conversely, if the porosity is greater than 80%, the strength of the porous material will be insufficient.

[0061] The porosity can be measured from a cross-section of the control layer 40. Specifically, the control layer 40 is removed from the electrolytic device 1 and washed to remove materials such as the second ion conductive material supported on the porous material. Next, the elemental distribution is measured using scanning electron microscope energy dispersive X-ray spectrometry (SEM-EDX) at a cross-section 10% from each surface toward the opposite surface on both the electrode-side surface and the electrolyte layer 30-side surface of the control layer 40. This allows for the distinction between the porous material and other materials, and the ratio of the pore area to the area of ​​the porous material is calculated. The porosity of the porous material can then be calculated by taking the average of the porosities at the two locations. Alternatively, the porosity can be determined after identifying the chemical composition of the control layer 40 using X-ray diffraction (XRD).

[0062] The pore diameter of the porous material is 1 mm or less, preferably 0.1 mm or less. This increases the pressure loss when liquid components move within the pores, thus suppressing their movement. The lower limit can be adjusted depending on the material used and the desired amount of seepage. The pore diameter can be calculated by measuring the cross-section of the porous material in the same way as measuring the porosity of the porous material described above.

[0063] Furthermore, porous materials can be hydrophobic in order to control the behavior of components of the electrolyte layer 30 leaching out to the electrodes. As an indicator of hydrophobicity, the water contact angle of the porous material is, for example, 45 degrees or more.

[0064] By changing the thickness of the control layer 40, it is possible to adjust the degree to which some of the components of the electrolyte layer 30 move to the electrodes. From the viewpoint of electrolytic cell fabrication, it is preferable that the thickness of the control layer 40 be approximately the same as the thickness of each layer, the anode 61, the cathode 51, and the electrolyte layer 30. The thickness of the control layer 40 is, for example, 1 mm or less.

[0065] The control of leaching in the control layer 40 will be described. Let the area of the second ion-conductive material on the surface of the cathode 51 or / and anode 61 side of the control layer 40 be A, and the area of the second ion-conductive material on the surface of the control layer 40 on the electrolyte layer 30 side be B. At this time, 0≦A≦B. That is, the area of the second ion-conductive material on the electrode-side surface of the control layer 40 is not less than zero and not more than the area of the surface on the electrolyte layer 30 side. By being within this range, the control layer 40 can suppress the leaching from the electrolyte layer 30 to the electrode, and an electrolytic device with excellent electrolytic efficiency can be provided. From the perspective of electrolytic efficiency, it is desirable to have a certain degree of leaching, and 0<A<B is desirable. It is more desirable that A is about half of B, that is, the leaching can be controlled to about 50%.

[0066] The boundary conditions will be described. When 0 = A, that is, when it is confirmed that the second ion-conductive material does not exist on the surface of the cathode 51 or / and anode 61 side, it is a case where the porous material has an ion-conductive material. When ions move from the electrolyte layer 30 to the electrode side, they move through the porous material at least near the interface on the electrode side in the movement path. When A = B, that is, when the same amount of the second ion-conductive material exists on the cathode 51 or / and anode 61 side and the electrolyte layer 30 side, it is a case where the amount of the ion-conductive material moving from the electrolyte layer 30 to the control layer 40 is small. When 0 = A = B, ions move through the porous material at least near the interface on the electrode side and near the interface on the electrolyte layer 30 side.

[0067] Let the area of the first ion-conductive material on the surface of the electrolyte layer 30 on the control layer 40 side be C, then B≦C. From the perspective of controlling leaching, preferably B<C. When B = C, that is, when the same amount of the second ion-conductive material on the cathode 51 or / and anode 61 side and the first ion-conductive material on the surface of the electrolyte layer 30 on the control layer 40 side exists, it is a case where leaching is suppressed within the control layer 40.

[0068] Whether the control layer 40 suppresses leakage can be determined by whether the relationship between A and B described above is satisfied. This will be explained using Figure 4. Figure 4 is a cross-sectional view of the electrolyte layer 30 and the control layer 40 extracted from the electrolytic device 1, drawn spaced apart from each other. In Figure 4, the positions for measuring A, B, and C are described as area A, area B, and area C, respectively. The measurement method will now be explained. First, the material between the cathode 51 and the anode 61 is removed from the electrolytic device 1, and the surface in contact with the electrodes is divided into two equal parts. The position of the control layer 40 is identified from the cross-section of the removed material, and the elemental distribution is measured using EDX at cross-sections at positions 5%, 10%, and 15% from each surface toward the opposite surface on the electrode side surface and the electrolyte layer 30 side surface of the control layer 40, and the average of the three is calculated. This allows for the distinction between porous material and secondary ion conductive material, and the area of ​​secondary ion conductive material can be calculated. If elemental distribution cannot be measured with EDX, XPS is used in combination.

[0069] When A=B, compare the area C of the first ion-conducting material in the electrolyte layer 30 with B. First, measure the elemental distribution of cross-sections at 5%, 10%, and 15% from the surface on the control layer 40 side of the electrolyte layer 30 toward the opposite side using EDX, and calculate the average of the three measurements. If elemental distribution cannot be measured with EDX, use XPS in combination.

[0070] If the area of ​​the first ion-conducting material and the second ion-conducting material B are compared and the area of ​​the second ion-conducting material is smaller, then A = B may be acceptable.

[0071] The method of manufacturing the control layer 40 is not limited, but for example, it can be manufactured in advance as a separate component and then laminated during the assembly of an electrolytic cell or a cell stack formed by stacking multiple electrolytic cells. The control layer 40 may be manufactured in advance in a manner that is in contact with the surface of the electrolyte layer 30 so as to be integrated with the electrolyte layer 30, and then laminated during the assembly of the electrolytic cell 20 or cell stack. The control layer 40 may also be manufactured in advance in a manner that is in contact with the surface of the electrode so as to be integrated with the electrode, and then laminated during the assembly of the electrolytic cell or cell stack.

[0072] (power supply) The power supply 70 can, for example, supply power to the electrolytic unit 10. The power supply 70 is electrically connected to the cathode 51 and anode 61 via, for example, the cathode channel plate 53, the anode channel plate 63, the cathode current collector plate 54, and the anode current collector plate 64. The power supply 70 can supply power to the electrolytic unit 10 to cause electrolytic reactions such as oxidation and reduction reactions. The reduction reaction at the cathode 51 and the oxidation reaction at the anode 61 are carried out using the electrical energy supplied from the power supply 70. The power supply 70 is connected to the cathode current collector plate 54 and the anode current collector plate 64 by, for example, wiring. Electrical equipment such as an inverter, converter, and battery may be installed between the electrolytic unit 10 and the power supply 70 as needed. The driving method for the electrolytic unit 10 is, for example, a constant voltage method or a constant current method, but is not limited to these.

[0073] The power source 70 may be a normal commercial power source or a battery, or it may be a power source that converts renewable energy into electrical energy and supplies it. Examples of such power sources include power sources that convert kinetic energy or potential energy such as wind power, hydropower, geothermal energy, and tidal power into electrical energy; power sources such as solar cells that have a photoelectric conversion element that converts light energy into electrical energy; power sources such as fuel cells and storage batteries that convert chemical energy into electrical energy; and power sources such as devices that convert vibration energy such as sound into electrical energy. The photoelectric conversion element has the function of separating charges using the energy of light such as irradiated sunlight. Examples of photoelectric conversion elements include pin junction solar cells, pn junction solar cells, amorphous silicon solar cells, multi-junction solar cells, monocrystalline silicon solar cells, polycrystalline silicon solar cells, dye-sensitized solar cells, and organic thin-film solar cells. The photoelectric conversion element may also be stacked with at least one of the cathode 51 and anode 61 inside the electrolytic unit 10.

[0074] Next, we will explain the operation of the electrolytic device 1 shown in Figure 1. Here, we will mainly explain the case where carbon monoxide (CO) is produced as the carbon compound.

[0075] First, mainly hydrogen ions (H+ The reaction process when ) contributes to the reaction is described below. When current is supplied from the power supply 70 between the anode 61 and the cathode 51, an oxidation reaction of water occurs at the anode 61 in contact with the anode supply fluid 65. Specifically, as shown in equation (1) below, the H2O contained in the anode supply fluid 65 is oxidized to oxygen (O2) and hydrogen ions (H + ) and are generated. 2H2O → 4H + +O2+4e - …(1)

[0076] H generated at anode 61 + These electrons move within the electrolyte layer 30 and control layer 40, reaching the vicinity of the cathode 51. Electrons (e) are generated based on the current supplied from the power supply 70 to the cathode 51. - ) and H moved near cathode 51 + This leads to a reduction reaction of carbon dioxide. Specifically, as shown in equation (2) below, CO2 supplied from cathode channel 52 to cathode 51 is reduced to produce CO. Also, as shown in equation (3) below, hydrogen ions (H + Hydrogen is produced when ) accepts an electron. At this time, hydrogen may be produced simultaneously with carbon monoxide. 2CO2 + 4H + +4e - → 2CO + 2H2O …(2) 2H + +2e - → H2…(3) When producing methane (CH4) as a carbon compound, the following reaction proceeds at the cathode. CO2 + 8H + +8e - → CH4 + 2H2O …(x) In this case, methane may be produced simultaneously with carbon monoxide and hydrogen.

[0077] Next, mainly hydroxide ions (OH) -The reaction process when ) contributes to the reaction is described below. When current is supplied from the power supply 70 between the anode 61 and the cathode 51, water and carbon dioxide are reduced near the cathode 51, as shown in equation (4) below, to produce carbon monoxide and hydroxide ions. In addition, hydrogen is produced when water accepts electrons, as shown in equation (5) below. At this time, hydrogen may be produced at the same time as carbon monoxide. The hydroxide ions produced by these reactions diffuse near the anode 61, and as shown in equation (6) below, the hydroxide ions are oxidized to produce oxygen (O2). 2CO2 + 2H2O + 4e - → 2CO + 4OH - …(4) 2H2O + 2e - → H2 + 2OH - …(5) 4OH - → 2H2O + O2 + 4e - …(6)

[0078] (Second embodiment) The case where the electrolytic device 1 has a cell stack structure will be described. Figure 5 is a schematic cross-sectional view showing a modified configuration of the electrolytic device according to the embodiment. The cell stack 80 has, in addition to the electrolytic cell 20 of the first embodiment, a bipolar plate 900, a cathode 951, a cathode channel 952, an anode 961, and an anode channel 962. By employing a cell stack in the electrolytic device 1, the amount of the substance to be reduced per unit floor area required for the installation of the electrolytic unit 10 increases, and thus the amount of reduction product produced can be increased. The number of stacked electrolytic cells is preferably, for example, 10 to 150.

[0079] If the electrolytic unit 10 has multiple electrolytic cells, the cathode supply fluid 55 and anode supply fluid 65 supplied to each electrolytic cell can be supplied from the same number of pipes as the number of electrolytic cells. If the number of pipes is less than the number of electrolytic cells, the fluids can be supplied by distributing the pipes.

[0080] Furthermore, the cathode discharge fluid 56 and anode discharge fluid 66 discharged from each electrolytic cell can be discharged through the same number of pipes as the number of electrolytic cells. If the number of pipes is less than the number of electrolytic cells, the pipes can be merged and the fluids discharged through them. The distribution of the cathode supply fluid 55 and anode supply fluid 65, and the merging of the cathode discharge fluid 56 and anode discharge fluid 66 may be performed outside the electrolytic unit 10 or inside the electrolytic unit 10. Here, the inside of the electrolytic unit 10 refers to the area in which multiple electrolytic cells are sandwiched between a pair of support plates and further tightened with bolts or the like.

[0081] The bipolar plate 900 has a first surface that contacts the anode 961 and a second surface that is opposite the first surface and contacts the cathode 951. The bipolar plate 900 may be electrically connected to the cathode 951 and the anode 961.

[0082] The bipolar plate 900 has a cathode channel 952 and an anode channel 962. Figure 6 is a diagram of the bipolar plate 900 extracted from the electrolytic device 1, and shows the bipolar plate 900 in three dimensions. Its main shape is the same as the cathode channel plate 53 described in Figure 3. The anode channel 962 and the cathode channel 952 are joined together, but are shown separately here for clarity. The arrows in Figure 6 indicate the main fluid movement paths when moving through the anode channel 962 and the cathode channel 952.

[0083] The bipolar plate 900 is provided between multiple membrane electrode assemblies to separate multiple electrolytic cells. Adjacent cathodes 951 and anodes 961 may be electrically connected via the bipolar plate 900. The cathode channel 952 of the bipolar plate 900 is provided, for example, on a first surface of the bipolar plate 900 and faces one cathode 951 of the multiple membrane electrode assemblies. The anode channel 962 of the bipolar plate 900 is provided, for example, on a second surface opposite the first surface of the bipolar plate 900 and faces another anode 961 of the multiple membrane electrode assemblies.

[0084] Multiple electrolytic cells are stacked, sandwiched between a pair of support plates, and further secured by tightening with bolts or the like. The cell stack may be installed with each stacked component positioned horizontally or vertically. When each stacked component is positioned horizontally, either the cathode or the anode may be placed on the top surface of the cell stack.

[0085] The bipolar plate 900 can be formed from the same material as the cathode channel plate 53 and anode channel plate 63 described above.

[0086] The invention of the embodiment is described below.

[0087] <1> A cathode for reducing the target substance and generating reduction products, An anode for oxidizing a target substance and producing oxidation products, An electrolyte layer having an electrolyte layer material between the cathode and the anode, containing at least one from the group consisting of a heat-resistant polymer, a solid acid, a solid salt, and a molten salt, and a first ion conductive material, Between the cathode and the electrolyte layer, or between the anode and the electrolyte layer, at least one of these is a porous material and a control layer in which a second ion conductive material is supported in at least a portion of the pores of the porous material. Equipped with, If A is the area of ​​the second ion-conducting material on the cathode side and / or the anode side surface of the control layer, and B is the area on the electrolyte layer side surface of the control layer, then 0 ≤ A ≤ B. Electrolyzer.

[0088] <2> If C is the area of ​​the first ion-conducting material on the surface of the electrolyte layer on the control layer side, then B <Cである、 <1> The electrolytic device described above.

[0089] <3> The first ion-conducting material comprises at least one of a solid acid, a solid salt, a molten salt, a liquid acid, an ionic liquid, and an ion-conducting polymer. <1> or <2> The electrolytic device described above.

[0090] <4> The second ion-conducting material comprises one or more of the first ion-conducting materials. <1> from <3> An electrolytic device as described in any one of the items.

[0091] <5> The first ion-conducting material and the second ion-conducting material are different materials from each other. <1> from <3> An electrolytic device as described in any one of the items.

[0092] <6> The porous material is a nonionic conductive material. <1> from <5> An electrolytic device as described in any one of the items.

[0093] <7> The porosity of the porous material is 20% or more and 80% or less. <1> from <6> An electrolytic device as described in any one of the items.

[0094] <8> The diameter of the aforementioned pore is 1 mm or less. <1> from <7> An electrolytic device as described in any one of the items.

[0095] <9> The electrolyte layer contains a matrix material. <1> from <8> An electrolytic device as described in any one of the items.

[0096] <10> The water contact angle in the control layer is 45 degrees or more. <1> from <9> An electrolytic device as described in any one of the items.

[0097] <11> The temperature of the electrolyte layer during operation of the electrolytic device is between 100°C and 500°C. <1> from <10> An electrolytic device as described in any one of the items.

[0098] <12> The cathode contains a basic compound. <1> from <11> An electrolytic device as described in any one of the items.

[0099] <13> The basic compound is an alkali metal salt or an alkaline earth metal salt. <12> The electrolytic device described above. [Explanation of Symbols]

[0100] 1 Electrolyzer 10 Electrolytic section 20 electrolytic cells 30 Electrolyte layer 40 Control Layer 50 Cathode section 51 Cathode 52 Cathode channel 53 Cathode flow channel plate 54 Cathode Current Collector Plate 55 Cathode Supply Fluid 56 Cathode discharge fluid 60 Anode section 61 Anodes 62 Anode channel 63 Anode channel plate 64 Anode current collector plate 65 Anode supply fluid 66 Anode discharge fluid 70 Power supply 80-cell stack 101 Land 102 Entrance 103 Exit 900 bipolar plates 951 Cathode 952 Cathode channel 961 Anode 962 Anode channel

Claims

1. A cathode for reducing the target substance and generating reduction products, An anode for oxidizing a target substance and producing oxidation products, An electrolyte layer having an electrolyte layer material between the cathode and the anode, containing at least one from the group consisting of a heat-resistant polymer, a solid acid, a solid salt, and a molten salt, and a first ion conductive material, A control layer is located between the cathode and the electrolyte layer, or between the anode and the electrolyte layer, and comprises a porous material and a second ion-conducting material supported in at least a portion of the pores of the porous material. Equipped with, If A is the area of ​​the second ion-conducting material on the cathode side and / or anode side surface of the control layer, and B is the area on the electrolyte layer side surface of the control layer, then 0 ≤ A ≤ B. Electrolyzer.

2. If C is the area of ​​the first ion-conducting material on the surface of the electrolyte layer on the control layer side, then B ≤ C. The electrolytic apparatus according to claim 1.

3. The first ion-conducting material comprises at least one of a solid acid, a solid salt, a molten salt, a liquid acid, an ionic liquid, and an ion-conducting polymer. The electrolytic apparatus according to claim 1.

4. The second ion-conducting material comprises one or more of the first ion-conducting materials. The electrolytic apparatus according to claim 1.

5. The first ion-conducting material and the second ion-conducting material are different materials from each other. The electrolytic apparatus according to claim 1.

6. The porous material includes a nonionic conductive material. The electrolytic apparatus according to claim 1.

7. The porosity of the porous material is 20% or more and 80% or less. The electrolytic apparatus according to claim 1.

8. The diameter of the aforementioned pore is 1 mm or less. The electrolytic apparatus according to claim 1.

9. The electrolyte layer contains a matrix material. The electrolytic apparatus according to claim 1.

10. The contact angle of water with the porous material is 45 degrees or more. The electrolytic apparatus according to claim 1.

11. The temperature of the electrolyte layer during operation of the electrolytic device is 100°C or higher and 500°C or lower. The electrolytic apparatus according to claim 1.

12. The cathode contains a basic compound. The electrolytic apparatus according to claim 1.

13. The basic compound is an alkali metal salt or an alkaline earth metal salt. The electrolytic apparatus according to claim 12.

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