Catalyst for oxygen evolution reaction in water electrolysis cell and production method therefor, and membrane-electrode assembly for water electrolysis cell and water electrolysis, each cell comprising catalyst

Abstract

Provided is a catalyst for an oxygen evolution reaction in a water electrolysis cell, the catalyst comprising: a carrier containing a fluorine-doped metal oxide; and water electrolysis catalyst particles located on the surface of the carrier and containing a fluorine-doped noble metal oxide, wherein in the entire fluorine-doped metal oxide, the content of fluorine is 1 at% to 20 at% relative to a total of 100 at% of the components as measured by high-resolution TEM, energy-dispersive X-ray spectroscopy analysis, and in the entire fluorine-doped noble metal oxide, the content of fluorine is 1 at% to 20 at% relative to a total of 100 at% of the components as measured by high-resolution TEM, energy-dispersive X-ray spectroscopy analysis.

Description

Catalyst for oxygen generation reaction in electrolytic cell and method for producing same, and membrane-electrode assembly and electrolytic cell for electrolytic cell including same

[0001] The present invention relates to a catalyst for an oxygen generation reaction in a water electrolysis cell and a method for producing the same, and a membrane-electrode assembly and a water electrolysis cell including the same.

[0002] This research was supported by the Ministry of Trade, Industry and Energy (MOTIE) and the Korea Institute of Energy Technology Evaluation and Planning (KETEP). (Project ID: 20223030040220)

[0003] Recent energy demands and environmental concerns demand sustainable supply, environmental friendliness, and high efficiency, and among these, hydrogen is attracting attention as a raw material for renewable energy.

[0004] Hydrogen energy is categorized as gray, blue, and green hydrogen depending on its production method. Gray and blue hydrogen use fossil fuels, which generate carbon dioxide during production and pose the problem of not being able to completely eliminate it. Green hydrogen is produced through water electrolysis. Because it produces no carbon dioxide, it is attracting attention as the ultimate eco-friendly energy source. Water electrolysis technology is required to produce green hydrogen.

[0005] Water electrolysis is an electrochemical technology that generates hydrogen and oxygen by electrolyzing water and transporting ions across a membrane. Water electrolysis can be divided into two half-cell reactions: the hydrogen evolution reaction (HER), which occurs at the reduction electrode, and the oxygen evolution reaction (OER), which occurs at the oxidation electrode.

[0006] Regarding catalysts for water electrolysis, especially for oxygen evolution electrodes of polymer electrolyte membrane (PEM) water electrolysis, iridium black and iridium oxide powder have been used as oxygen evolution reaction catalysts for conventional PEM water electrolysis oxygen evolution electrodes, but improvements are required for their low dispersibility, low electrical conductivity, and instability.

[0007] The present invention provides a catalyst for oxygen evolution reaction in electrolysis cells that can exhibit high electrochemical durability and conductivity even in high-voltage and low-pH electrolysis operation environments by applying it to electrolysis cell electrodes while reducing the amount of precious metals used.

[0008] In one embodiment, a catalyst for an oxygen evolution reaction in a water electrolysis cell is provided, comprising: a support containing a fluorine-doped metal oxide; and electrolysis catalyst particles located on a surface of the support and containing a fluorine-doped noble metal or a fluorine-doped noble metal oxide; wherein the fluorine content is 1 at% to 20 at% with respect to 100 at% of the total sum of components as measured by high-resolution TEM energy discharge X-ray spectral analysis in the entire fluorine-doped metal oxide, and wherein the fluorine content is 1 at% to 20 at% with respect to 100 at% of the total sum of components as measured by high-resolution TEM energy discharge X-ray spectral analysis in the entire fluorine-doped noble metal or fluorine-doped noble metal oxide.

[0009] In another embodiment, an oxygen generation electrode including a catalyst for an oxygen generation reaction of the above-described electrolysis cell is provided.

[0010] In another embodiment, a method for manufacturing an oxygen generation electrode is provided, comprising: (i) mixing a metal oxide into a solution containing a precious metal oxide precursor, and then drying the mixture to prepare a dried product; and (ii) mixing the dried product and a fluorine precursor, and then heat-treating the mixture to prepare a catalyst for an oxygen generation reaction of a water electrolysis cell; (iii) mixing the catalyst for an oxygen generation reaction of the water electrolysis cell and an ionomer to prepare a slurry; and (iv) dispersing the slurry.

[0011] In another embodiment, a membrane-electrode assembly for a water electrolysis cell is provided, comprising: a polymer electrolyte membrane; an oxygen generation electrode positioned on one side of the polymer electrolyte membrane; and a hydrogen generation electrode positioned on the other side of the polymer electrolyte membrane.

[0012] In another embodiment, a water electrolysis cell comprising a membrane-electrode assembly for the water electrolysis cell is provided.

[0013] A catalyst for oxygen evolution reaction of a water electrolysis cell manufactured according to an embodiment of the present invention can exhibit high electrochemical catalytic activity and conductivity even in a high-voltage, low-pH water electrolysis operating environment by applying it to a water electrolysis cell electrode while reducing the amount of precious metal used.

[0014] Figure 1 is a schematic diagram showing a membrane-electrode assembly (MEA) for a water electrolysis cell.

[0015] Figures 2 to 5 are high-resolution TEM images and energy discharge X-ray spectral analysis (EDS) mapping TEM images of Example 1.

[0016] Figure 6 is a graph showing the electrolysis performance of membrane-electrode assemblies manufactured in Example 1, Example 3, Comparative Example 1, and Comparative Example 2.

[0017] Below, specific implementation examples are described in detail to facilitate their implementation by those skilled in the art. However, the present invention may be implemented in various different forms and is not limited to the implementation examples described herein.

[0018] The terminology used herein is for the purpose of describing exemplary embodiments only and is not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise.

[0019] “Combination of these” means a mixture, laminate, composite, copolymer, alloy, blend, reaction product, etc. of the components.

[0020] It should be understood that terms such as "include," "comprise," or "have" are intended to specify the presence of a feature, number, step, component, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, components, or combinations thereof.

[0021] To clearly illustrate various layers and regions in the drawings, their thicknesses are enlarged, and similar parts are designated by the same drawing reference numerals throughout the specification. When an element such as a layer, film, region, or plate is said to be "over" or "on" another element, this includes not only the case where it is "directly over" the other element, but also the case where there are other elements in between. Conversely, when an element is said to be "directly over" another element, it means that there are no other elements in between.

[0022] “Layer” includes not only shapes formed on the entire surface when observed in a plan view, but also shapes formed on some surfaces.

[0023] The average particle size can be measured by methods well known to those skilled in the art, for example, by measuring with a particle size analyzer, or by measuring with transmission electron microscope images or scanning electron microscope images. Alternatively, the average particle size can be obtained by measuring using dynamic light scattering, performing data analysis, counting the number of particles for each particle size range, and calculating from the counted number. Unless otherwise defined, the average particle size is the diameter (D) of the particles in the particle size distribution that have a cumulative volume of 50% by volume. 50 ) can mean. In addition, unless otherwise defined, the average particle size is obtained by measuring the size (diameter or length of major axis) of about 20 particles randomly in a transmission electron microscope image to obtain a particle size distribution, and the diameter (D) of the particle having a cumulative volume of 50% by volume in the particle size distribution 50 ) may be taken as the average particle diameter.

[0024] “Or” is not interpreted as exclusive, for example, “A or B” is interpreted as including A, B, A+B, etc.

[0025] “Metal” is interpreted as a concept that includes common metals, transition metals, and metalloids (semi-metals).

[0026] Catalyst for oxygen evolution reaction

[0027] In this specification, a catalyst for oxygen evolution reaction means a catalyst applied to an electrode (hereinafter referred to as an oxygen evolution electrode) where an oxygen evolution reaction (OER) takes place. In other words, it means a catalyst included in an oxygen evolution electrode described below.

[0028] According to one embodiment, a catalyst for an oxygen evolution reaction of a water electrolysis cell comprises: a support containing a fluorine-doped metal oxide; and water electrolysis catalyst particles located on a surface of the support and containing a fluorine-doped noble metal or a fluorine-doped noble metal oxide, wherein the content of fluorine relative to 100 at% of the total sum of components measured by high-resolution TEM energy discharge X-ray spectroscopy (TEM-EDS) in the entire fluorine-doped metal oxide is 1 at% to 20 at%, and the content of fluorine relative to 100 at% of the total sum of components measured by high-resolution TEM energy discharge X-ray spectroscopy (TEM-EDS) in the entire fluorine-doped noble metal or fluorine-doped noble metal oxide is 1 at% to 20 at%.

[0029] The performance and durability of the above oxygen generation reaction catalyst can be improved depending on the type, shape, and content of the carrier and water electrolysis catalyst particles.

[0030] In polymer electrolyte membrane electrolysis cells, precious metals or precious metal oxides are used as oxygen evolution reaction catalysts, and active research is being conducted to support precious metal oxide catalysts on a support to reduce the content of expensive precious metal oxides and increase the specific surface area. However, there is a problem that a high content of precious metals must be supported due to the low electrical conductivity of the support, and in order to lower the content of precious metals, it is necessary to develop a support that can compensate for the low electrical conductivity. Accordingly, in one embodiment, a fluorine-doped noble metal or a fluorine-doped noble metal oxide is used as an oxygen evolution reaction catalyst, and a fluorine-doped metal oxide is used as a carrier, and the problem of difficulty in controlling the doping amount and uniform fluorine doping due to defluorination during a solvent synthesis process due to the reactivity of fluorine is solved, and a water electrolysis electrode having high electrical conductivity and electrochemical corrosion resistance is proposed, in which the uniformly fluorine-doped noble metal or fluorine-doped noble metal oxide reduces the energy of the rate-determining step of electrolysis due to fluorine doping, thereby improving electrochemical activity.

[0031] carrier

[0032] According to one embodiment, a support contains a fluorine-doped metal oxide, and the metal may include, for example, tungsten (W), titanium (Ti), nickel (Ni), ruthenium (Ru), tantalum (Ta), tin (Sn), cobalt (Co), or a combination thereof. Accordingly, the metal oxide may include tungsten oxide, titanium oxide, nickel oxide, ruthenium oxide, tantalum oxide, tin oxide, cobalt oxide, or a combination thereof, and preferably includes tin oxide. When the oxygen evolution reaction catalyst of a water electrolysis cell includes the support, there is an advantage in that it can exhibit high catalytic activity even if the content of the noble metal is low by compensating for the low electrical conductivity of the water electrolysis catalyst particles containing the noble metal oxide. In addition, since the metal oxide included in the support is doped with fluorine, it is possible to prevent the doped fluorine or the metal of the metal oxide from being eluted in the water electrolysis operating environment, thereby deteriorating the membrane electrode performance.

[0033] The carrier may have various shapes, for example, a sphere, a wire, or a rod, and preferably a sphere. The carrier may be in the form of secondary particles in which primary particles are aggregated, and the average particle diameter (D) of the primary particles 50 ) may be 0.005 ㎛ to 0.5 ㎛, for example 0.007 ㎛ to 0.4 ㎛, 0.009 ㎛ to 0.3 ㎛, or 0.01 ㎛ to 0.2 ㎛, and the average particle diameter (D of the secondary particles 50) may be 0.05 ㎛ to 1.0 ㎛, for example, 0.08 ㎛ to 0.9 ㎛, or 0.1 ㎛ to 0.8 ㎛. The primary particles may be crystalline particles or grains. A plurality of primary particles may form grain boundaries and aggregate with each other to form secondary particles, and the primary particles may have various shapes such as spherical or quasi-spherical (such as flake shapes). The average particle diameter is obtained by randomly measuring the size (diameter or length of major axis) of about 20 particles in a scanning electron microscope image of a carrier to obtain a particle size distribution, and the diameter (D) of particles having a cumulative volume of 50% by volume in the particle size distribution 50 ) may be taken as the average particle size. The catalyst for the oxygen generation reaction of the electrolysis cell according to one embodiment may be in the form of electrolysis catalyst particles, which will be described later, positioned on the surface of the carrier, thereby forming a conductive network to reduce the surface resistance of the electrode and improve the performance of the electrolysis cell.

[0034] In one embodiment, the carrier may be included in an amount of 20 wt% to 80 wt%, for example, 25 wt% to 65 wt%, or 30 wt% to 50 wt%, based on 100 wt% of the total of the carrier and electrolysis catalyst particles. When the content of the carrier and electrolysis catalyst particles is as described above, the oxygen evolution reaction catalyst of the electrolysis cell including the same may form a conductive network to reduce the surface resistance of the electrode and improve the performance of the electrolysis cell.

[0035] In one embodiment, the fluorine content relative to the total 100 at% of components measured by high-resolution TEM energy discharge X-ray spectroscopy (TEM-EDS) in the entire fluorine-doped metal oxide is 1 at% to 20 at%, for example, 1 at% to 15 at%, 1 at% to 12 at%, 4 at% to 12 at%, or 8 at% to 12 at%. When the fluorine content in the entire fluorine-doped metal oxide satisfies the above range, uniform fluorine doping becomes possible, which can reduce the sheet resistance of the electrode and improve the performance of the electrolysis cell.

[0036] Water electrolysis catalyst particles

[0037] In one embodiment, the electrolysis catalyst particles are positioned on the surface of the aforementioned carrier and contain a fluorine-doped precious metal or a fluorine-doped precious metal oxide. The precious metal may be a non-platinum-based precious metal, and for example, the non-platinum-based precious metal may include palladium (Pd), ruthenium (Ru), iridium (Ir), alloys thereof, or combinations thereof. The precious metal oxide according to one embodiment is IrO x (x is an integer from 1 to 3), RuO x (x is an integer from 1 to 3), PdO x (x is an integer from 1 to 3), IrMO x (M includes Ru, Sn, Ti, Te, Nb, or a combination thereof, and x is an integer from 1 to 3), or a combination thereof. When the electrolysis catalyst particle includes the noble metal oxide, it has the advantage of exhibiting high catalytic activity.

[0038] The average particle diameter (D) of the above electrolysis catalyst particles 50) may be 0.001 ㎛ to 0.015 ㎛, for example, 0.002 ㎛ to 0.012 ㎛, 0.004 ㎛ to 0.01 ㎛. The average particle diameter is obtained by randomly measuring the size (diameter or length of major axis) of about 20 particles in a scanning electron microscope image of a water electrolysis catalyst particle to obtain a particle size distribution, and the diameter (D) of the particle having a cumulative volume of 50% by volume in the particle size distribution 50 ) may be taken as the average particle size. The catalyst for the oxygen generation reaction of the electrolysis cell according to one embodiment may be in a form in which the electrolysis catalyst particles are positioned on the surface of the aforementioned carrier, thereby forming a conductive network to reduce the surface resistance of the electrode and improve the performance of the electrolysis cell.

[0039] With respect to the total 100 wt% of the carrier and electrolysis catalyst particles, the electrolysis catalyst particles may be included in an amount of 20 wt% to 80 wt%, for example, 40 wt% to 75 wt%, or 50 wt% to 70 wt%. When the content of the carrier and electrolysis catalyst particles is as described above, the oxygen evolution reaction catalyst including them can form a conductive network to reduce the surface resistance of the electrode and improve the performance of the electrolysis cell.

[0040] The fluorine content relative to the total 100 at% of components measured by high-resolution TEM energy discharge X-ray spectroscopy (EDS) in the entire fluorine-doped noble metal oxide is 1 at% to 20 at%, for example, 2 at% to 19 at%, or 3 at% to 10 at%. When the fluorine content in the entire fluorine-doped noble metal oxide satisfies the above range, uniform fluorine doping becomes possible, which reduces the energy of the rate-determining step of electrolysis, thereby improving electrochemical activity and enhancing the performance of the electrolysis cell.

[0041] According to one embodiment, a catalyst for an oxygen evolution reaction of a water electrolysis cell is produced by doping fluorine into a support containing a metal oxide and water electrolysis catalyst particles containing a noble metal or a noble metal oxide in a one-pot process, thereby improving catalytic activity and electrical conductivity by supporting the water electrolysis catalyst particles containing a noble metal or a noble metal oxide while maintaining the fluorine doping. On the other hand, if a support containing a fluorine-doped metal oxide is produced and then the water electrolysis catalyst particles are supported, the highly reactive fluorine dopant is defluorinated during the process of supporting the water electrolysis catalyst particles, and thus the fluorine doping is not maintained, resulting in loss of electrical conductivity and reduction in water electrolysis performance.

[0042] oxygen generation electrode

[0043] The above oxygen evolution electrode refers to an electrode where an oxygen evolution reaction (OER) occurs, and the oxygen evolution electrode may include a catalyst for the oxygen evolution reaction of the water electrolysis cell. Since the catalyst for the oxygen evolution reaction of the water electrolysis cell has been described above, a description thereof will be omitted.

[0044] The above oxygen generation electrode may contain 60 wt% to 95 wt% of the oxygen generation reaction catalyst relative to the total 100 wt% of the oxygen generation electrode, for example, 65 wt% to 85 wt%, or 70 wt% to 95 wt%.

[0045] The above oxygen generation electrode may further include an ion conductor to improve the adhesion of the catalyst and to transfer hydrogen ions, and the ion conductor may include a cation exchanger to secure ion conductivity. At this time, the oxygen generation electrode may include 1 wt% to 25 wt% of the ion conductor with respect to 100 wt% of the total oxygen generation electrode, for example, 2 wt% to 20 wt%, or 3 wt% to 18 wt%.

[0046] The above cation exchanger may be a sulfonic acid group, a carboxyl group, a boronic acid group, a phosphoric acid group, a phosphonic acid group, an imide group, a sulfonimide group, a sulfonamide group, or a sulfonic acid fluoride.

[0047] The above ion conductor may be a fluorine-based ion conductor, a hydrocarbon-based ion conductor, or a mixture thereof. The above fluorine-based ion conductor may be a fluorine-based polymer having the cation exchange group in the side chain and containing fluorine in the main chain, such as poly(perfluorosulfonic acid), poly(perfluorocarboxylic acid), etc. The hydrocarbon-based ion conductor is a hydrocarbon-based polymer having the cation exchange group in the side chain [e.g., sulfonated polyimide (S-PI), sulfonated polyarylethersulfone (S-PAES), sulfonated polyetheretherketone (SPEEK), sulfonated polybenzimidazole (SPBI), sulfonated polysulfone (S-PSU), sulfonated polystyrene (S-PS), sulfonated polyphosphazene, sulfonated polyquinoxaline, sulfonated polyketone, sulfonated polyphenylene oxide, sulfonated polyether sulfone, Sulfonated polyether ketone, sulfonated polyphenylene sulfone, sulfonated polyphenylene sulfide, sulfonated polyphenylene sulfide sulfone, sulfonated polyphenylene sulfide sulfone nitrile,It can be sulfonated polyarylene ether, sulfonated polyarylene ether nitrile, sulfonated polyarylene ether ether nitrile, sulfonated polyarylene ether sulfone ketone, etc.

[0048] The ion conductor according to one embodiment may have hydrogen ion conductivity. The ion conductor having the hydrogen ion conductivity may also have H substituted with Na, K, Li, Cs or tetrabutylammonium in the cation exchanger at the end of the side chain. When H is substituted with Na in the ion exchanger at the end of the side chain, NaOH is used during the preparation of the catalyst composition, and when H is substituted with tetrabutylammonium, tetrabutylammonium hydroxide is used. K, Li or Cs may also be substituted using an appropriate compound. Since this substitution method is widely known in the art, a detailed description thereof will be omitted.

[0049] The above ion conductor can be used as a single substance or in the form of a mixture, and can also be optionally used together with a non-conductive compound for the purpose of further improving adhesion to a polymer electrolyte membrane. The content of the non-conductive compound can be appropriately adjusted depending on the intended use. As the non-conductive compound, at least one selected from polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), ethylene / tetrafluoroethylene (ETFE), ethylene chlorotrifluoro-ethylene copolymer (ECTFE), polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer (PVdF-HFP), dodecylbenzenesulfonic acid, and sorbitol can be used.

[0050] Method for manufacturing an oxygen generation electrode

[0051] A method for manufacturing an oxygen generation electrode of a water electrolysis cell according to one embodiment includes: (i) a step of mixing a metal oxide into a solution containing a precious metal oxide precursor and then drying the mixture to prepare a dried product; (ii) a step of mixing the dried product and a fluorine precursor and then heat-treating the mixture to prepare a catalyst for an oxygen generation reaction of a water electrolysis cell; (iii) a step of mixing the catalyst for an oxygen generation reaction of the water electrolysis cell and an ionomer to prepare a slurry; and (iv) a step of dispersing the slurry.

[0052] According to a method for manufacturing an oxygen generation electrode of a water electrolysis cell according to one embodiment, a process of simultaneously doping a mixture of a support containing a metal oxide and a water electrolysis catalyst particle containing a precious metal oxide with fluorine, i.e., a one-pot process, is performed, whereby fluorine is simultaneously doped into the water electrolysis catalyst particle containing a precious metal or precious metal oxide and the support containing the metal oxide, thereby reducing the energy of the rate-determining step of electrolysis of the precious metal or precious metal oxide, thereby improving electrochemical activity, and a water electrolysis electrode having high electrical conductivity and electrochemical corrosion resistance can be manufactured through the support containing the fluorine-doped metal oxide. On the other hand, if a carrier containing a fluorine-doped metal oxide is manufactured and then electrolysis catalyst particles containing a noble metal or a noble metal oxide are supported, the highly reactive fluorine dopant may be defluorinated during the electrolysis catalyst particle support process, and the fluorine doping may not be maintained, resulting in loss of electrical conductivity and reduction in electrolysis performance. In addition, there is a problem that an additional process is required for fluorine doping on electrolysis catalyst particles containing a noble metal or a noble metal oxide.

[0053] In one embodiment, in the step of mixing a metal oxide into a solution containing a noble metal oxide precursor of step (i) and then drying the mixture to prepare a dried product, the type of the noble metal oxide precursor may include IrCl3, IrCl3 hydrate, IrCl4, H2Cl6Ir, Ir(CH3COO)3, or a combination thereof, and preferably IrCl3 hydrate. In addition, the type of the solvent required to prepare the solution is not limited as long as it can dissolve the noble metal oxide precursor. For example, the solvent may include water, alcohol, ethylene glycol, or a combination thereof, and the alcohol may be methanol, ethanol, butanol, or isopropanol.

[0054] The noble metal oxide precursor may be included in an amount of 25 wt% to 88 wt% relative to 100 wt% of the total noble metal oxide precursor and metal oxide of the above step (i), for example, 31 wt% to 84 wt%, or 57 wt% to 81 wt%. When the content of the noble metal oxide precursor is within the above range, the catalyst for the oxygen evolution reaction of the electrolysis cell including it may form a conductive network to reduce the sheet resistance of the electrode and improve the performance of the electrolysis cell.

[0055] In the above-mentioned dry material, the carrier containing the metal oxide may be a primary particle. At this time, the primary particle may have various shapes such as spherical or quasi-spherical (flake shape, etc.), and the average particle diameter (D) of the primary particle 50 ) may be from 0.005 μm to 0.5 μm, for example from 0.007 μm to 0.4 μm, from 0.009 μm to 0.3 μm, or from 0.01 μm to 0.2 μm.

[0056] In one embodiment, in the step of mixing the dried material and the fluorine precursor of step (ii) and then heat-treating them to prepare a catalyst for the oxygen evolution reaction of the electrolysis cell, the type of the fluorine precursor may include NH4F, NH4HF2, or a combination thereof, and preferably NH4F. At this time, the molar ratio of the dried material and the fluorine precursor may be included as 1:1 to 1:30, for example, 1:1 to 1:20, 1:2 to 1:20, 1:3 to 1:20, 1:8 to 1:20, 1:13 to 1:20, or 1:18 to 1:20. When the molar ratio of the dried material and the fluorine precursor is included in the above range, the amount of fluorine to be doped can be easily controlled, making it possible to uniformly dope with fluorine, thereby reducing the sheet resistance of the electrode and improving the performance of the electrolysis cell.

[0057] After the mixing process of the above-mentioned dry material and fluorine precursor is performed, a heat treatment process may be performed. The heat treatment may be performed in an inert gas atmosphere or a reducing gas atmosphere, the heat treatment temperature may be 80°C to 450°C, 100°C to 430°C, or 120°C to 400°C, and the time for the heat treatment process may be 4 hours to 8 hours, 4.5 hours to 7.5 hours, or 5 hours to 7 hours.

[0058] After mixing the above dry material and fluorine precursor and heat-treating, the carrier containing the fluorine-doped metal oxide in the oxygen generation reaction catalyst of the electrolysis cell may be a secondary particle. At this time, the secondary particle may be formed by agglomeration of a plurality of primary particles forming grain boundaries, and the average particle diameter (D) of the secondary particles 50 ) may be from 0.05 μm to 1.0 μm, for example from 0.08 μm to 0.9 μm, or from 0.1 μm to 0.8 μm.

[0059] In one embodiment, in the step of preparing a mixture by mixing the oxygen generation reaction catalyst and the ionomer of the electrolysis cell of step (iii), the ionomer may be a cation conductor having a cation exchange group capable of exchanging cations, or an anion conductor having an anion exchange group capable of exchanging anions such as hydroxy ions, carbonates, or bicarbonates.

[0060] The above cation exchange group may be any one selected from the group consisting of a sulfonic acid group, a carboxyl group, a boronic acid group, a phosphoric acid group, an imide group, a sulfonimide group, a sulfonamide group, and combinations thereof, and may generally be a sulfonic acid group or a carboxyl group.

[0061] The above cation conductor may include the above cation exchange group, and may include a fluorine-based polymer containing fluorine in the main chain; a hydrocarbon-based polymer such as benzimidazole, polyamide, polyamideimide, polyimide, polyacetal, polyethylene, polypropylene, acrylic resin, polyester, polysulfone, polyether, polyetherimide, polyester, polyethersulfone, polyetherimide, polycarbonate, polystyrene, polyphenylene sulfide, polyetheretherketone, polyetherketone, polyarylethersulfone, polyphosphazene or polyphenylquinoxaline; a partially fluorinated polymer such as a polystyrene-graft-ethylenetetrafluoroethylene copolymer or a polystyrene-graft-polytetrafluoroethylene copolymer; and a sulfone imide.

[0062] In addition, the cation conductor may substitute H in the cation exchange group at the end of the side chain with Na, K, Li, Cs or tetrabutylammonium. When replacing H in the cation exchange group at the end of the side chain with Na, NaOH is used during the preparation of the carbon structure composition, and when replacing H with tetrabutylammonium, tetrabutylammonium hydroxide is used. K, Li or Cs may also be substituted using an appropriate compound.

[0063] As the above anion conductor, a polymer doped with a metal hydroxide can generally be used, and specifically, a metal hydroxide doped poly(ethersulfone), polystyrene, a vinyl polymer, poly(vinyl chloride), poly(vinylidene fluoride), poly(tetrafluoroethylene), poly(benzimidazole), or poly(ethylene glycol) can be used.

[0064] The ionomer may be included in an amount of 10 to 45 wt% relative to 100 wt% of the total oxygen generation reaction catalyst and ionomer of the electrolysis cell, for example, 10 to 40 wt%, 10 to 35 wt%, or 10 to 33 wt%. When the content of the ionomer is within the above range, the performance of the electrolysis cell is improved, and at the same time, there is an advantage in that aggregation between ionomers due to an excess of ionomer can be suppressed.

[0065] In one embodiment, in the step of dispersing the slurry of step (iv), the slurry may be manufactured through any one of the following dispersion methods: ultrasonic dispersion, stirring, a three-roll mill, a ball mill, planetary stirring, high-pressure dispersion, and a mixture thereof.

[0066] Membrane-electrode assembly for electrolysis cell

[0067] A membrane-electrode assembly for a water electrolysis cell according to one embodiment comprises a polymer electrolyte membrane, an oxygen generation electrode positioned on one side of the polymer electrolyte membrane, and a hydrogen generation electrode positioned on the other side of the polymer electrolyte membrane.

[0068] The membrane-electrode assembly for the above-described electrolysis cell is illustrated in FIG. 1. The membrane-electrode assembly (20) for the electrolysis cell according to FIG. 1 includes a polymer electrolyte membrane (25); an oxygen generation electrode (21) positioned on one side of the polymer electrolyte membrane; and a hydrogen generation electrode (22) positioned on the other side of the polymer electrolyte membrane.

[0069] Since the oxygen generation electrode has been described above, a detailed description will be omitted, and the hydrogen generation electrode and the polymer electrolyte membrane will be described in detail.

[0070] The above hydrogen generation electrode refers to an electrode where a hydrogen evolution reaction (HER) occurs, and the hydrogen generation electrode may include a catalyst for the hydrogen evolution reaction. The hydrogen evolution reaction catalyst may include active particles and a carrier, and the active particles may include a noble metal, and the noble metal may be a platinum-based noble metal.

[0071] The platinum-based precious metal may be platinum (Pt) and / or a Pt-M alloy. The M may be palladium (Pd), ruthenium (Ru), iridium (Ir), osmium (Os), gallium (Ga), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), silver (Ag), gold (Au), zinc (Zn), tin (Sn), molybdenum (Mo), tungsten (W), lanthanum (La), or rhodium (Rh).

[0072] Specifically, the Pt-M alloy includes Pt-Pd, Pt-Sn, Pt-Mo, Pt-Cr, Pt-W, Pt-Ru, Pt-Ni, Pt-Co, Pt-Y, Pt-Ru-W, Pt-Ru-Ni, Pt-Ru-Mo, Pt-Ru-Rh-Ni, Pt-Ru-Sn-W, Pt-Ru-Ir-Ni, Pt-Co-Mn, Pt-Co-Ni, Pt-Co-Fe, Pt-Co-Ir, Pt-Co-S, Pt-Co-P, Pt-Fe, Pt-Fe-Ir, Pt-Fe-S, Pt-Fe-P, Pt-Au-Co, Pt-Au-Fe, Pt-Au-Ni, Pt-Ni, Pt-Ni-Ir, Pt-Cr, Pt-Cr-Ir, or these Mixtures can be used.

[0073] The above-mentioned carrier may be a carbon-based carrier. The carbon-based carrier may be graphite, super P, carbon fiber, carbon sheet, carbon black, Ketjen Black, Denka black, acetylene black, carbon nanotube (CNT), carbon sphere, carbon ribbon, fullerene, activated carbon, carbon nanofiber, carbon nanowire, carbon nanoball, carbon nanohorn, carbon nanocage, carbon nanoring, ordered nano- / meso-porous carbon, carbon aerogel, mesoporous carbon, graphene, stabilized carbon, activated carbon, or a combination thereof.

[0074] The above oxygen generation electrode and the hydrogen generation electrode may each include only a catalyst layer including an oxygen generation reaction catalyst and a hydrogen generation reaction catalyst, but may also include an electrode substrate together with the catalyst layer. At this time, the electrode substrate may serve to support the electrode and diffuse the fuel and oxidant to the catalyst layer. The electrode substrate is not specifically limited and any known electrode substrate may be used, but specifically, carbon paper, carbon cloth, carbon felt, or metal cloth (a porous film composed of a fiber-like metal cloth or a cloth formed of polymer fibers on which a metal film is formed on the surface) that can be used as a conductive substrate may be used. The electrode substrate may be one that has been water-repellent treated with a fluorine-based resin, in which case, the reactant diffusion efficiency may be prevented from being reduced by water generated during operation of the water electrolysis cell. As the above fluorine-based resin, polytetrafluoroethylene, polyvinylidene fluoride, polyhexafluoropropylene, polyperfluoroalkyl vinyl ether, polyperfluorosulfonyl fluoride, alkoxy vinyl ether, fluorinated ethylene propylene, polychlorotrifluoroethylene or a copolymer thereof can be used.

[0075] The above oxygen generation electrode and the above hydrogen generation electrode may include a microporous layer in addition to the above-described catalyst layer and electrode substrate. The microporous layer serves to enhance the reactant diffusion effect, and may generally include a conductive powder having a small particle size, such as carbon powder, carbon black, acetylene black, activated carbon, carbon fiber, fullerene, carbon nanotube, carbon nanowire, carbon nano-horn, or carbon nano ring.

[0076] polymer electrolyte membrane

[0077] The polymer electrolyte membrane has an ion exchange function that transfers hydrogen ions generated at an oxygen generation electrode to a hydrogen generation reaction catalyst. According to one embodiment, the polymer electrolyte membrane may include a porous support including a plurality of pores, and an ion conductor filling the pores of the porous support.

[0078] The porous support may be a fluorinated support or a nanoweb support. The fluorinated support may correspond to, for example, expanded polytetrafluoroethylene (e-PTFE) having a microstructure of polymer fibrils or a microstructure in which nodes are interconnected by fibrils. In addition, a film having a microstructure of polymer fibrils without nodes may also be used as the porous support.

[0079] The fluorinated support may include a perfluorinated polymer. The porous support may correspond to a more porous and stronger porous support obtained by extruding dispersion polymerized PTFE into a tape in the presence of a lubricant and stretching the material obtained thereby. In addition, the amorphous content of the PTFE may be increased by heat treating the e-PTFE at a temperature exceeding the melting point of the PTFE (about 342°C). The e-PTFE film manufactured by the method may have micropores with various diameters and a porosity. The e-PTFE film manufactured by the method may have at least 35% pores, and the diameter of the micropores may be about 0.01 to 1 μm (micrometer).

[0080] The above nano web support may be a non-woven fibrous web composed of a plurality of randomly oriented fibers. The non-woven fibrous web refers to a sheet having a structure of individual fibers or filaments that are interlaid, but not in the same manner as a woven fabric. The non-woven fibrous web may be manufactured by carding, garnetting, air-laying, wet-laying, melt blowing, spun bonding, or stitch bonding.

[0081] The fibers may comprise one or more polymeric materials, and any material that is generally used as a fiber-forming polymeric material may be used, and specifically, a hydrocarbon-based fiber-forming polymeric material may be used. For example, the fiber-forming polymeric material may comprise a polyolefin such as polybutylene, polypropylene, and polyethylene, a polyester such as polyethylene terephthalate and polybutylene terephthalate, a polyamide (nylon-6 and nylon-6,6), a polyurethane polybutene, polylactic acid, polyvinyl alcohol, polyphenylene sulfide, polysulfone, a fluid crystalline polymer, polyethylene-co-vinylacetate, polyacrylonitrile, a cyclic polyolefin, polyoxymethylene, a polyolefin-based thermoplastic elastomer, or a combination thereof.

[0082] The above nano web support may be a support in which nano fibers are integrated in the form of a non-woven fabric containing a large number of pores.

[0083] The above nanofibers exhibit excellent chemical resistance and have hydrophobicity, so hydrocarbon polymers that are free from moisture-induced deformation in high-humidity environments can be preferably used. Specifically, the hydrocarbon polymers may include nylon, polyimide, polyaramid, polyetherimide, polyacrylonitrile, polyaniline, polyethylene oxide, polyethylene naphthalate, polybutylene terephthalate, styrene butadiene rubber, polystyrene, polyvinyl chloride, polyvinyl alcohol, polyvinylidene fluoride, polyvinyl butylene, polyurethane, polybenzoxazole, polybenzimidazole, polyamideimide, polyethylene terephthalate, polyphenylene sulfide, polyethylene, polypropylene, copolymers thereof, or mixtures thereof.

[0084] The above nanoweb support is an aggregate of nanofibers manufactured by electrospinning and randomly arranged. At this time, the nanofibers may have an average diameter of 40 nm to 5000 nm when the average diameter of 50 fibers is measured using a scanning electron microscope (JSM6700F, JEOL) and calculated from the average, taking into account the porosity and thickness of the nanoweb. When the average diameter of the nanofibers is within the above range, the mechanical strength is excellent and an appropriate porosity can be secured.

[0085] The thickness of the nonwoven fibrous web may be 10 ㎛ to 50 ㎛ or 15 ㎛ to 43 ㎛. When the thickness of the nonwoven fibrous web is within the above range, the mechanical strength, weight reduction, and integration may be excellent. The nonwoven fibrous web may have a basic weight of 5 to 30 mg / cm. 2It can be. If the basis weight of the nonwoven fibrous web is less than the above numerical range, visible pores may be formed, making it difficult to function as a porous support, and if it exceeds the above numerical range, it may be manufactured in the form of paper or fabric in which pores are hardly formed. The porosity can be calculated by the ratio of the air volume in the porous support to the total volume of the porous support according to the following mathematical formula 1. At this time, the total volume is calculated by manufacturing a rectangular sample and measuring the width, length, and thickness, and the air volume can be obtained by measuring the mass of the sample and then subtracting the polymer volume calculated inversely from the density from the total volume.

[0086] [Mathematical Formula 1]

[0087] Porosity (%) = (air volume in porous support / total volume of porous support) X 100

[0088] For example, the porosity of the porous support may be 30 to 90%. When the porosity of the porous support is within the above range, problems such as a decrease in the impregnation property of the ion conductor or a problem of post-processing not proceeding smoothly due to a decrease in stability may not occur.

[0089] The above ion conductor is as described above. The ion conductor included in the polymer electrolyte membrane may be the same as or different from the ion conductor included in the oxygen generation electrode. For example, the ion conductor included in the polymer electrolyte membrane may be the same as the ion conductor included in the oxygen generation electrode.

[0090] Susan Haesel

[0091] In one embodiment, the electrolysis cell comprises a membrane-electrode assembly for the electrolysis cell.

[0092] The above electrolytic cell is the same as the known one except that it includes a membrane-electrode assembly according to the present application, and therefore a detailed description thereof is omitted.

[0093] Hereinafter, examples and comparative examples of the present invention are described. The following examples are merely illustrative of the present invention, and the present invention is not limited to the following examples.

[0094] Example 1

[0095] 1. Preparation of catalyst for oxygen generation reaction

[0096] 1 g of SnO2 powder is mixed with a solution of 0.3 g of iridium chloride hydrate dissolved in 0.5 ml of ethanol, and then dried at 60°C to prepare a dried product. The prepared dried product and 5 g of NH4F, a fluorine precursor, are mixed to design the molar ratio of SnO2 and NH4F to be 1:20, and then the powder is homogeneously mixed to a particle size of 150 μm or less to prepare a mixture. Here, the amount of fluorine doped can be controlled by adjusting the amounts of the fluorine precursor and the prepared dried product. The prepared mixture is heat-treated at a temperature of 400°C for 6 hours in an inert gas atmosphere or a reducing gas atmosphere, and the heat-treated powder is washed and filtered using ethanol and distilled water, and then dried at a temperature of 60°C for 12 hours to prepare a catalyst for an oxygen generation reaction.

[0097] 2. Manufacturing of a membrane-electrode assembly containing a catalyst for oxygen evolution reaction

[0098] The prepared oxygen evolution reaction catalyst and ionomer solution were mixed so that the ionomer / catalyst ratio was 0.3. The mixed catalyst slurry was dispersed and stirred for 24 hours to prepare a catalyst composition for the oxygen evolution reaction. The above-mentioned catalyst composition for the oxygen evolution reaction is referred to as the first catalyst composition.

[0099] A second catalyst composition was prepared by mixing a catalyst having a platinum particle content of 46 wt% and an ionomer solution on a graphite carrier so that the ionomer / carbon ratio was 1.0. The first catalyst composition was thinly applied to a transfer substrate by spraying, decaling, or ultrasonic spray coating to prepare a first electrode, and the second catalyst composition was applied to another transfer substrate to prepare a second electrode. Then, the first electrode was transferred to one side of a polymer electrolyte membrane, and the second electrode was transferred to the opposite side and bonded to form a membrane-electrode assembly.

[0100] Example 2

[0101] In the manufacture of the catalyst for oxygen evolution reaction, the catalyst for oxygen evolution reaction and the membrane-electrode assembly were manufactured in substantially the same manner as in Example 1, except that 1.5 g of NH4F, a fluorine precursor, was used and the molar ratio of SnO2 and NH4F was designed to be 1:6.

[0102] Example 3

[0103] In the manufacture of the catalyst for oxygen evolution reaction, the catalyst for oxygen evolution reaction and the membrane-electrode assembly were manufactured in substantially the same manner as in Example 1, except that 0.15 g of NH4F, a fluorine precursor, was used and the molar ratio of SnO2 and NH4F was designed to be 1:1.

[0104] Comparative Example 1

[0105] Tetradecylamine (C 14 H 31N)(95%) 1.28 g is dissolved in 22.5 ml of an aqueous ethanol solution (ethanol:water = 1:2.5), and then 20 ml of ethanol in which 4.8 g of tin tetrachloride (SnCl4) and 0.48 g of NH4F as a fluorine precursor are dissolved are added, and mixed for 1 hour. Next, the mixture is mixed in 200 ml of a 1.5 mM ammonia solution, and refluxed at 80°C for 72 hours, washed using centrifugation, and dried using a heat-drying or freeze-drying method. The dried powder is heat-treated in an air atmosphere at a temperature of 400°C for 3 hours to obtain a fluorine-doped SnO2 powder.

[0106] 1 g of the fluorine-doped SnO2 powder prepared above is dispersed in a solution of 0.074 g of iridium acetate (Ir(CH3COO)3) and 0.08 g of sodium hydroxide dissolved in 20 ml of ethylene glycol, and then the mixture is reacted at 160°C for 1 hour in an inert gas atmosphere, followed by cooling. Afterwards, the catalyst is washed using centrifugation and dried by heat or freeze drying to prepare the final catalyst.

[0107] Comparative Example 2

[0108] 1 g of SnO2 powder is dispersed in 22.5 ml of an aqueous ethanol solution (ethanol:water = 1:2.5), and 20 ml of ethanol in which 0.48 g of NH4F as a fluorine precursor is dissolved is added. Mixing is performed for 1 hour, followed by reflux reaction at 80°C for 72 hours, washing using centrifugation, and drying using a heat-drying or freeze-drying method. The dried powder is heat-treated in an air atmosphere at 400°C for 3 hours to obtain a fluorine-doped SnO2 powder.

[0109] 1 g of the fluorine-doped SnO2 powder prepared above is dispersed in a solution of 0.074 g of iridium acetate (Ir(CH3COO)3) and 0.08 g of sodium hydroxide dissolved in 20 ml of ethylene glycol, and then the mixture is reacted at 160°C for 1 hour in an inert gas atmosphere, followed by cooling. Afterwards, the catalyst is washed using centrifugation and dried by heat or freeze drying to prepare the final catalyst.

[0110]

[0111] Evaluation Example 1: Fluorine Content Analysis

[0112] In order to confirm the fluorine content of the fluorine-doped metal oxide in the carriers manufactured in the examples and comparative examples, the fluorine atoms were measured by high-resolution TEM energy discharge X-ray spectroscopy (TEM-EDS) to confirm the fraction in the entire fluorine-doped metal oxide, and the results are shown in Table 1.

[0113] Next, in order to confirm the fluorine content of the fluorine-doped noble metal oxide in the water electrolysis catalyst particles manufactured in the examples and comparative examples, the fluorine atoms measured by high-resolution TEM energy discharge X-ray spectroscopy (TEM-EDS) were confirmed as a fraction in the entire fluorine-doped noble metal oxide, and the results are shown in Table 1.

[0114] Fluorine content in carrier (at%) Fluorine content in water electrolysis catalyst particles (at%) Example 1 10.19.2 Example 26.34.0 Example 31.10.9 Comparative Example 10.10 Comparative Example 200

[0115] Referring to Table 1, SnO2 and IrO synthesized according to Examples 1 to 3 x It can be confirmed that the amount of fluorine doping can be controlled when fluorine doping is performed in a single pot in a mixture of SnO2 and IrO is added to the fluorine-doped SnO2 during the synthesis process. x Comparative Example 1, or doping fluorine into the synthesized SnO2, and adding IrO to the fluorine-doped SnO2x In the case of comparative example 2 containing fluorine, it can be confirmed that fluorine doping is not performed smoothly.

[0116] In order to confirm the structure of IrOx / FTO manufactured in one pot in Example 1, IrOx / FTO was observed using scanning transmission electron microscopy (STEM) and energy discharge X-ray spectroscopy (EDS) mapping analysis, and the results are shown in FIGS. 2 to 5.

[0117] Referring to FIGS. 2 to 5, the STEM image and energy discharge X-ray spectroscopy (EDS) mapping analysis of IrOx / FTO confirmed that fluorine was evenly distributed in IrOx / FTO through the one-pot process, and at the same time, it was confirmed that the Ir catalyst was well supported on tin (Sn) oxide.

[0118] Evaluation Example 2: Electrical Conductivity Evaluation

[0119] The first electrode manufactured in the examples and comparative examples was cut to 2 cm x 2 cm, and then electrodes were made with silver plates at both corners, and the surface resistance was measured using the van der pauw surface resistance measurement method to evaluate the electrical conductivity, and the results are shown in Table 2.

[0120] Electrical Conductivity (mS / cm) Example 1 16.26 Example 26.69 Example 33.38 Comparative Example 10.001 Comparative Example 20.0006

[0121] Referring to Table 2, SnO2 and IrO synthesized according to Examples 1 to 3 x In the case of performing fluorine doping in a one-pot manner in the mixture, fluorine is doped during the process of synthesizing SnO2, and IrO is added to the fluorine-doped SnO2. x Comparative Example 1 or fluorine-doped SnO2 containing IrO or fluorine-doped SnO2 x It can be confirmed that the electrical conductivity is superior compared to the case of comparative example 1 containing .

[0122] Evaluation Example 3: Water Electrolysis Performance Evaluation

[0123] The membrane-electrode assembly manufactured in the examples and comparative examples was supplied with distilled water at 80°C at a flow rate of 5 ml / min, and a protocol was applied to measure current and resistance at voltages up to 2 V using linear voltammetry at 10 mV / s to evaluate the water electrolysis performance, and the results are shown in Fig. 6.

[0124] Referring to Fig. 6, it can be confirmed that the electrolysis performance is improved in Examples 1 and 3, where the fluorine doping is performed smoothly, compared to Comparative Examples 1 and 2, where the fluorine doping is not performed smoothly. In addition, it can be confirmed that as the amount of fluorine doping increases, the electrolysis performance is improved in Example 1 compared to Example 3.

[0125] Although the preferred embodiments have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concepts defined in the following claims also fall within the scope of the present invention.

Claims

1. A carrier containing a metal oxide doped with fluorine; and A catalyst for oxygen generation reaction of a water electrolysis cell, comprising a water electrolysis catalyst particle located on the surface of the carrier and containing a fluorine-doped noble metal or a fluorine-doped noble metal oxide; The fluorine content is 1 at% to 20 at% with respect to the total 100 at% of the components measured by high-resolution TEM energy discharge X-ray spectrum analysis in the entire fluorine-doped metal oxide, A catalyst for oxygen evolution reaction in a water electrolysis cell having a fluorine content of 1 at% to 20 at% relative to 100 at% of the total components as measured by high-resolution TEM energy discharge X-ray spectral analysis in the entire fluorine-doped noble metal or fluorine-doped noble metal oxide.

2. In paragraph 1, The metal oxide is a catalyst for oxygen evolution reaction in a water electrolysis cell including tungsten oxide, titanium oxide, nickel oxide, ruthenium oxide, tantalum oxide, tin oxide, cobalt oxide, or a combination thereof.

3. In paragraph 1, The above metal oxide is a catalyst for the oxygen evolution reaction of a water electrolysis cell, which is tin oxide.

4. In paragraph 1, The above-mentioned carrier is a catalyst for oxygen generation reaction in a water electrolysis cell having a shape of a sphere, wire, or rod.

5. In paragraph 1, The above carrier is in the form of secondary particles in which primary particles are aggregated, The average particle diameter of the above primary particles (D 50 ) is 0.005 ㎛ to 0.5 ㎛, The average particle diameter of the above secondary particles (D 50 ) is a catalyst for oxygen generation reaction in a water electrolysis cell having a particle size of 0.05 ㎛ to 1.0 ㎛.

6. In paragraph 1, A catalyst for oxygen generation reaction in a water electrolysis cell, comprising 20 to 80 wt% of the carrier relative to 100 wt% of the total carrier and water electrolysis catalyst particles.

7. In paragraph 1, The above precious metal oxide is IrO x A catalyst for oxygen evolution reaction in a water electrolysis cell, wherein x is an integer from 1 to 3.

8. In paragraph 1, The average particle diameter (D) of the above water electrolysis catalyst particles 50 ) is a catalyst for oxygen generation reaction in a water electrolysis cell having a particle size of 0.001 ㎛ to 0.015 ㎛.

9. An oxygen generation electrode including a catalyst for oxygen generation reaction of a water electrolysis cell according to Article 1. 10.(ⅰ) A step of mixing a metal oxide into a solution containing a precious metal oxide precursor and then drying it to produce a dried product; (ⅱ) a step of mixing the above-mentioned dry material and fluorine precursor and then heat-treating them to produce a catalyst for oxygen generation reaction of a water electrolysis cell; (ⅲ) a step of preparing a slurry by mixing the oxygen generation reaction catalyst and ionomer of the above electrolysis cell; and (ⅳ) A method for manufacturing an oxygen generation electrode, comprising: a step of dispersing the above slurry.

11. In paragraph 10, A method for manufacturing an oxygen evolution electrode, wherein the noble metal oxide precursor comprises IrCl3, IrCl3 hydrate, IrCl4, H2Cl6Ir, Ir(CH3COO)3, or a combination thereof.

12. In paragraph 10, A method for manufacturing an oxygen evolution electrode, wherein the above fluorine precursor comprises NH4F, NH4HF2, or a combination thereof.

13. In paragraph 10, A method for manufacturing an oxygen generation electrode, wherein in the step (ii), the molar ratio of the drying agent and the fluorine precursor is 1:1 to 1:

30.

14. Polymer electrolyte membrane; An oxygen generation electrode according to claim 9 located on one side of the polymer electrolyte membrane; and A membrane-electrode assembly for a water electrolysis cell, comprising a hydrogen generation electrode positioned on the other side of the polymer electrolyte membrane.

15. A water electrolysis cell comprising a membrane electrode assembly according to Article 14.

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