Catalyst for oxygen evolution reaction of water electrolysis cell, and membrane-electrode assembly for water electrolysis cell and water electrolysis cell comprising same

Abstract

The present disclosure relates to: a catalyst for an oxygen evolution reaction of a water electrolysis cell; and a membrane-electrode assembly for a water electrolysis cell, and a water electrolysis cell, comprising same. By modifying the surfaces of core particles included in the catalyst for an oxygen evolution reaction of a water electrolysis cell, so as to be hydrophobic, durability against water during a reaction can be improved, and at the same time bonding with ion conductor side chains can be increased, thereby improving performance and durability.

Description

Catalyst for oxygen evolution reaction in electrolytic cell, membrane-electrode assembly for electrolytic cell including same, and electrolytic cell

[0001] The present disclosure relates to a catalyst for an oxygen evolution reaction in a water electrolysis cell, a membrane-electrode assembly for an water electrolysis cell including the same, and a water electrolysis cell, and more particularly, to a catalyst for an oxygen evolution reaction in a water electrolysis cell including the same, wherein durability against water during a reaction is improved by hydrophobicly modifying the surface of a core particle including a precious metal oxide, and at the same time, performance and durability can be improved by increasing bonding with an ion conductor side chain, and a membrane-electrode assembly for an water electrolysis cell including the same, and a water electrolysis cell.

[0002] This disclosure relates to the results of a project (Project ID: 20022451) carried out with the support of the Materials and Components Technology Development Project of the Ministry of Trade, Industry and Energy and the Korea Institute for Advancement of Technology (KEIT).

[0003] Recent energy demands and environmental concerns demand sustainable supply, environmental friendliness, and high efficiency, leading to a growing need for the development of new energy sources and energy-utilizing devices. Renewable energy sources, such as solar and wind power, are attracting significant attention due to their environmentally friendly and sustainable characteristics and advantages, as well as their potential to replace fossil fuels, which are causing environmental problems and are depleting.

[0004] However, the supply of these renewable energies is unstable due to unstable weather conditions, regional restrictions, and characteristics, which hinders their expansion as next-generation power sources.

[0005] To overcome this, hydrogen is attracting attention as a raw material for renewable energy.

[0006] Hydrogen energy is classified into gray, blue, and green hydrogen depending on the production method. Gray hydrogen refers to byproduct hydrogen produced as a byproduct of petrochemical or steelmaking processes and extracted hydrogen produced through a catalytic reaction using fossil fuels. Blue hydrogen refers to hydrogen that captures the carbon dioxide emitted when producing gray hydrogen and does not emit it into the atmosphere.

[0007] Gray and blue hydrogen have the problem that carbon dioxide is produced during the production process or cannot be completely removed because it uses fossil fuels.

[0008] Green hydrogen refers to hydrogen produced through the electrolysis of infinite water. Because the hydrogen production process produces no carbon dioxide, it is attracting attention as the ultimate eco-friendly energy source. Water electrolysis technology is necessary to produce green hydrogen.

[0009] 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.

[0010] The types of electrolysis mentioned above are, depending on the electrolyte membrane, representative ones such as polymer electrolyte membrane electrolysis (PEM), alkaline electrolysis (AEC), anion exchange membrane electrolysis (AEM), and solid oxide electrolysis (SOECs).

[0011] Among these, polymer electrolyte membrane (PEM) electrolysis utilizes a polymer electrolyte membrane as an electrolyte, such as a cation exchange membrane such as Nafion, which allows the movement of hydrogen ions. Polymer electrolyte electrolysis utilizes a platinum catalyst and a cation exchange membrane, enabling high current density operation and high energy efficiency, allowing for miniaturization of the device.

[0012] As a catalyst for such polymer electrolyte membrane electrolysis, a catalyst in which precious metal nanoparticles are supported on a carbon support is typically used. However, such a catalyst has the disadvantage of poor durability against water and has the problem of difficulty in binding to hydrophobic ion conductor catalyst chains.

[0013] According to one embodiment, a catalyst for oxygen evolution reaction of a water electrolysis cell is provided, in which durability against water is improved during a reaction by hydrophobicly modifying the surface of a core particle including a precious metal oxide, and at the same time, bonding with an ion conductor catalyst chain is increased, thereby improving performance and durability.

[0014] According to another embodiment, a membrane-electrode assembly for a water electrolysis cell and a water electrolysis cell including a catalyst for an oxygen generation reaction of the water electrolysis cell are provided.

[0015] A catalyst for an oxygen generation reaction in an electrolytic cell according to one embodiment comprises a composite active particle comprising a core particle including a precious metal oxide and having a hydrophobic surface including a fluorine group, a silane compound, a hydrophobic polymer, or a combination thereof.

[0016] The above composite active particles may have a contact angle with water within a range of 25° to 200°.

[0017] The oxide of the above precious metal is IrO x (wherein x is an integer from 1 to 3), RuO x (where x is an integer from 1 to 3), IrMO x(wherein M includes Ru, Sn, Ti, Te, Ta, Nb, Sb, Se, W, or a combination thereof, and x is an integer from 1 to 3), or may include a combination thereof.

[0018] The above composite active particles may contain the fluorine group in an amount ranging from 3 wt% to 20 wt% based on 100 wt% of the core particles.

[0019] The above composite active particle further comprises a hydrophobic surface layer positioned on the core particle, and the hydrophobic surface layer may comprise a fluorine group, the silane compound, the hydrophobic polymer, or a combination thereof.

[0020] The area of ​​the hydrophobic surface layer of the above composite active particle may be in the range of 50% to 100% of the total surface area of ​​the core particle.

[0021] The thickness of the hydrophobic surface layer may be 1 nm to 8 nm.

[0022] The above fluorine group is derived from an organic fluorine compound, and the hydrophobic surface layer including the fluorine group may further include an organic fluorine compound.

[0023] The silane compound may include methyltrimethoxysilane, trimethylethoxysilane, trimethylchlorosilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropylmethyldiethoxysilane, a combination thereof, or a condensate thereof.

[0024] The above composite active particles may contain the silane compound in an amount ranging from 5 wt% to 30 wt% based on 100 wt% of the core particles.

[0025] The hydrophobic polymer may include an acrylic polymer, an epoxy polymer, a polyamide polymer, a polyethylene polymer, an EVC polymer, a polyester polymer, a PVC polymer, a polyurethane, or a combination thereof.

[0026] The above composite active particles may contain the hydrophobic polymer in an amount ranging from 7 wt% to 40 wt% based on 100 wt% of the core particles.

[0027] The content of the above composite active particles may be 60 wt% or more with respect to 100 wt% of the oxygen generation reaction catalyst.

[0028] It further includes a carrier that supports the above composite active particles, and the carrier may include a metal oxide.

[0029] The carrier may be included in an amount of 10 to 200 parts by weight per 100 parts by weight of the composite active particles.

[0030] According to another embodiment, a membrane-electrode assembly for a water electrolysis cell comprises: a polymer electrolyte membrane; an oxygen evolution electrode positioned on one side of the polymer electrolyte membrane and including a catalyst for the oxygen evolution reaction; and a hydrogen evolution electrode positioned on the other side of the polymer electrolyte membrane.

[0031] The membrane-electrode assembly for the above-mentioned electrolysis cell may have a voltage increase rate of 7% or less, as expressed by the following equation 1.

[0032] [Formula 1]

[0033] Voltage increase rate (%) = (voltage after driving - initial voltage) / (initial voltage) × 100

[0034] According to another embodiment, a hydroelectric cell comprises the membrane-electrode assembly.

[0035] According to one embodiment, a catalyst for an oxygen generation reaction of a water electrolysis cell can have improved durability against water during a reaction by modifying its surface to be hydrophobic, and at the same time, performance and durability can be improved due to increased bonding with ion conductor side chains.

[0036] Figures 1 and 2 are side views showing composite active particles according to one embodiment.

[0037] FIG. 3 is a schematic diagram showing a membrane-electrode assembly (MEA) for a water electrolysis cell according to one embodiment.

[0038] Figure 4 is a photograph showing the results of measuring the contact angle of the oxygen generation reaction catalyst of the electrolysis cell manufactured in Examples 1 to 4 and Comparative Examples with respect to water.

[0039] Figure 5 is a graph showing the results of evaluating the IV characteristics of a membrane-electrode assembly including an oxygen evolution reaction catalyst of a water electrolysis cell manufactured in Examples 1 to 4 and a comparative example.

[0040] Hereinafter, embodiments of the present disclosure will be described in detail so that those skilled in the art can easily implement the present disclosure. However, the present disclosure may be implemented in various different forms and is not limited to the embodiments described herein.

[0041] As used herein, “combination thereof” means a mixture, laminate, composite, copolymer, alloy, blend, reaction product, etc. of the components.

[0042] It should be understood that the terms “include,” “comprising,” or “having” used in this specification 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.

[0043] Unless otherwise defined herein, "substitution" means that a hydrogen atom in a compound is replaced by a halogen atom (F, Cl, Br or I), a hydroxy group, an alkoxy group, a nitro group, a cyano group, an amino group, an azido group, an amidino group, a hydrazino group, a hydrazono group, a carbonyl group, a carbamyl group, a thiol group, an ester group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, a C1 to C20 alkyl group, a C2 to C20 alkenyl group, a C2 to C20 alkynyl group, a C6 to C30 aryl group, a C7 to C30 arylalkyl group, a C1 to C4 alkoxy group, a C1 to C20 heteroalkyl group, a C3 to C20 heteroarylalkyl group, a C3 to C30 cycloalkyl group, a C3 to C15 cycloalkenyl group, a C6 to C15 cycloalkynyl group, It means substituted with a substituent including a C2 to C20 heterocycloalkyl group or a combination thereof.

[0044] Unless otherwise defined herein, “alkyl group” means a straight or branched chain, saturated, monovalent hydrocarbon group (e.g., methyl group, ethyl group, propyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, iso-amyl group, hexyl group, etc.).

[0045] Unless otherwise defined herein, “alkenyl group” means a straight or branched chain, saturated, monovalent hydrocarbon group having at least one carbon-carbon double bond (e.g., an ethenyl group).

[0046] Unless otherwise defined herein, “alkoxy group” means an alkyl group linked through oxygen, for example, methoxy, ethoxy, and sec-butyloxy groups.

[0047]

[0048] 1. Catalyst for oxygen generation reaction in electrolysis cell

[0049] In this specification, the catalyst for oxygen evolution reaction means a catalyst applied to an electrode (hereinafter, “oxygen evolution electrode”) where an oxygen evolution reaction (OER) takes place. That is, it is a catalyst included in the oxygen evolution electrode described below.

[0050] A catalyst for an oxygen generation reaction in a water electrolysis cell according to one embodiment includes a core particle including a precious metal oxide, a composite active particle having a hydrophobic surface including a fluorine group, a silane compound, a hydrophobic polymer, or a combination thereof.

[0051] The above "surface" refers to the outer portion of the core particle, and in the present specification, the composite active particle means a core particle that has been modified with a hydrophobic surface to have a hydrophobic surface, or a core particle that has a hydrophobic surface and further includes a hydrophobic surface layer having a certain thickness range. The specific details of the hydrophobic surface layer are described below.

[0052] The composite active particles included in the oxygen generation reaction catalyst of the above electrolysis cell are described with reference to Fig. 1.

[0053] Fig. 1 is a side view illustrating a composite active particle according to one embodiment. Fig. 1 illustrates a composite active particle having only a hydrophobic surface.

[0054] In Fig. 1, the composite active particle (3) includes a core particle (1) containing a precious metal oxide, and has a hydrophobic surface (A) by modifying the core particle (1) into a hydrophobic surface. In Fig. 1, the entire surface of the core particle (1) is depicted as having a hydrophobic surface (A), but this is only for convenience and shows that the hydrophobic surface (A) can be formed on the surface of the core particle (1), and is not limited thereto.

[0055] The composite active particle having the above hydrophobic surface (A) can exhibit hydrophobicity, and the hydrophobicity at this time can be expressed as a contact angle with respect to water.

[0056] The above composite active particles may have a contact angle with water within a predetermined range. The method for measuring the contact angle with water is according to the method described in “Measurement of Contact Angle with Water” in Evaluation Example 1 of this specification.

[0057] For example, the lower limit of the contact angle of the composite active particles with water may be about 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, 85°, 90°, 95°, 100°, 105°, 110°, 115°, 120°, 130°, 140° or 150°, and the upper limit may be about 200°, 195°, 190°, 185°, 180°, 175°, 170°, 165°, 160°, 155°, 150°, 145°, 140°, 135°, 130°, It can be 125°, 120°, 115°, 110°, 105° or 100°.

[0058] The contact angle of the composite active particles with respect to water may be within a range of greater than or equal to any one of the lower limits described above; less than or equal to any one of the upper limits described above; or greater than or equal to any one of the lower limits described above and less than or equal to any one of the upper limits described above.

[0059] By including composite active particles having a contact angle for water within the above range, durability for water can be improved, and at the same time, performance and durability can be improved due to increased bonding with ion conductor side chains.

[0060] The hydrophobic surface includes a fluorine group, a silane compound, a hydrophobic polymer, or a combination thereof, as described above.

[0061] Hereinafter, each case in which the hydrophobic surface includes a fluorine group, a silane compound, or a hydrophobic polymer is described.

[0062] In one embodiment, the hydrophobic surface may include a fluorine group. In this case, the fluorine group may be attached to or substituted for the core particle.

[0063] For example, the fluorine group may be formed by (i) plasma treatment under a fluorine-containing gas or (ii) heat-treating a mixture obtained by mixing the core particle with a fluorine-containing precursor.

[0064] Below, plasma treatment and heat treatment are described respectively.

[0065] In one embodiment, the fluorine group may be formed by plasma treatment under a fluorine-containing gas. The plasma treatment may be performed by placing core particles into a plasma generating device and then generating plasma under a fluorine-containing gas.

[0066] As the above fluorine-containing gas, a fluorine-containing molecular gas may be used alone, or a mixed gas obtained by mixing the fluorine-containing molecular gas and a dilution gas may be used.

[0067] The above fluorine-containing molecular gas may include tetrafluoromethane (CF4), trifluoromethane (CHF3), dichlorodifluoromethane (CF2Cl2), chlorotrifluoromethane (CF3Cl), hexafluoroethane (C2F6), pentafluoroethane (CF3CHF2), 1,1,1,2-tetrafluoroethane (CF3CFH2), octafluoropropane (C3F8), 1,1,1,2,3,3,3-heptafluoropropane (CF3CHFCF3), 1,1,1,3,3-pentafluoropropane (CF3CH2CHF2), 1,1,1,3,3-pentafluorobutane (CF3CH2CF2CH3), nitrogen trifluoride (NF3), sulfur hexafluoride (SF6), or a combination thereof.

[0068] The above diluting gas may include nitrogen gas, helium gas, argon gas, neon gas, krypton gas, xenon gas, radon gas, or a combination thereof.

[0069] In one example, the fluorine-containing gas may be used alone as the fluorine-containing molecular gas.

[0070] During the above plasma treatment, the gas flow rate, temperature, power, and time can be appropriately adjusted to effectively promote the reaction between the core particles and the plasma.

[0071] For example, the gas flow rate may be within a range of 0.1 sccm to 300 sccm, the temperature may be within a range of 2 °C to 25 °C, the power may be within a range of 100 W to 2000 W, and the time may be within a range of 0.1 second to 10 minutes, but is not limited thereto.

[0072] In another embodiment, the fluorine group may be formed by placing a fluorine-containing precursor and a core particle in a reaction vessel, mixing them to obtain a mixture, and then performing a heat treatment on the mixture. In the present specification, the fluorine-containing precursor refers to a material that contains fluorine but is in a stage prior to attaching a fluorine group to the surface of the core particle.

[0073] As the above fluorine-containing precursor, an organic fluorine compound monomer or an inorganic fluorine compound can be used without using a fluorine-containing polymer.

[0074] When a fluorine-containing polymer is used as a precursor, the surface of the core particle is coated with the polymer. However, a thick polymer coating layer reduces the catalytic activity for the oxygen evolution reaction, and it is difficult to form a uniformly hydrophobic surface over the entire surface of the oxygen evolution reaction catalyst. Furthermore, after heat treatment, no fluorine groups are present on the surface of the oxygen evolution reaction catalyst, making it difficult to achieve the objectives of the present disclosure.

[0075] The above organic fluorine compound monomer is R'-F xmay include. The R' may be an alkyl group, an aryl group, a benzyl group, a vinyl group, or an acyl group, and the x may be an integer from 1 to 6. More specifically, the organic fluorine precursor may be, but is not limited to, C2H5F (ethyl fluoride), C7H7F (benzyl fluoride), CH3COF (acetyl fluoride), (CNF)3 (cyanuric fluoride), C2H3F (vinyl fluoride), (CH3)4NF (tetramethylammonium fluoride), or a mixture thereof.

[0076] In addition, the above inorganic fluorine compound is MF x may include. The M may be H, NH4, Ca, Si, P, B, Al or a compound thereof, and the x may be an integer from 1 to 6. More specifically, the inorganic fluorine compound may be, but is not limited to, HF, NH4F, CaF2, SiF6, PF3, PF5, (NH4)2SiF6, ClF6, NH4BF4, (NH4)2AlF6, or a mixture thereof. When HF is used as a fluorine-containing precursor, care must be taken in handling.

[0077] The above mixing can be performed according to a known method.

[0078] For example, the mixing can be performed using a homogeneous mixer, a high-pressure disperser, a ball mill, a powder mixer, or a resonant acoustic mixer.

[0079] The temperature and time during the above heat treatment process can be appropriately adjusted as needed.

[0080] In one example, the temperature may be in the range of 150°C to 300°C, and the time may be in the range of 2 hours to 4 hours, but is not limited thereto.

[0081] The above composite active particles may contain the fluorine group within a predetermined range to have a contact angle with water within the aforementioned range.

[0082] For example, the lower limit of the content of the fluorine group included in the composite active particle with respect to 100 wt% of the core particle may be about 3 wt%, 4 wt%, 5 wt%, 6 wt%, or 7 wt%, and the upper limit may be about 20 wt%, 18 wt%, 16 wt%, 14 wt%, 12 wt%, 10 wt%, 9 wt%, 8 wt%, or 7 wt%. The composite active particle may include the fluorine group in a range that is more than or exceeds any one of the lower limits described above; less than or less than any one of the upper limits described above; or more than or exceeds any one of the lower limits described above and less than or less than any one of the upper limits described above, with respect to 100 wt% of the core particle.

[0083] When the above fluorine group exists on the surface of the core particle within the above-mentioned range, a contact angle for water within the above-mentioned range can be secured, and thus durability for water can be improved, and at the same time, bonding with the side chain of the ion conductor can be increased, so that performance and durability can be improved.

[0084] In another embodiment, the composite active particle may have a hydrophobic surface comprising a silane compound, a hydrophobic polymer, or a combination thereof.

[0085] Figure 2 is a side view illustrating a composite active particle according to another embodiment. Figure 2 illustrates a composite active particle further including a hydrophobic surface layer positioned on a core particle together with a hydrophobic surface.

[0086] In FIG. 2, when the composite active particle (3) has a hydrophobic surface including the silane compound, hydrophobic polymer, or a combination thereof, the composite active particle (3) has a hydrophobic surface on the core particle (1) and may further include a hydrophobic surface layer (2) positioned on the core particle (1).

[0087] In one example, the composite active particle (3) further includes a hydrophobic surface layer (2) positioned on the core particle (1), and the hydrophobic surface layer (2) may include a fluorine group, the silane compound, a hydrophobic polymer, or a combination thereof.

[0088] The above hydrophobic surface layer (2) can be positioned on the core particle (1).

[0089] In order for the composite active particles to have the aforementioned contact angle with water, the area of ​​the hydrophobic surface layer can be appropriately controlled.

[0090] The lower limit of the area of ​​the hydrophobic surface layer of the composite active particle relative to the total surface area of ​​the core particle may be about 50%, 55%, 60%, 65%, 70%, 75%, 80% or 85%, and the upper limit thereof is not specifically limited, but may be about 100%, 95%, 90%, 85%, 80% or 75%. The area of ​​the hydrophobic surface layer of the composite active particle relative to the total surface area of ​​the core particle may be equal to or greater than any one of the lower limits described above, or may be within a range equal to or greater than any one of the lower limits described above, and equal to or less than any one of the upper limits described above.

[0091] By including a hydrophobic surface layer within the aforementioned range, the oxygen evolution reaction catalyst has improved durability against water, and at the same time, the bonding with the ion conductor side chain is increased, thereby providing an oxygen evolution reaction catalyst of a water electrolysis cell with improved performance and durability.

[0092] The thickness of the hydrophobic surface layer can be appropriately adjusted as needed, for example, the lower limit of the thickness of the hydrophobic surface layer can be about 1 nm, 1.5 nm, 2 nm, 2.5 nm, 3 nm, 3.5 nm, 4 nm, 4.5 nm or 5 nm, and the upper limit can be about 8 nm, 7 nm, 6 nm, 5 nm, 4 nm or 3 nm. The thickness of the surface layer can be more than or exceeding any one of the lower limits described above; less than or equal to any one of the upper limits described above; or more than or exceeding any one of the lower limits described above and less than or equal to any one of the upper limits described above.

[0093] In one embodiment, the hydrophobic surface layer may include a fluorine group. The fluorine group included in the hydrophobic surface layer may be formed by "(ii) heat-treating a mixture obtained by mixing the core particle with a fluorine-containing precursor," and this may particularly apply when the fluorine-containing precursor is an organic fluorine compound monomer.

[0094] For example, the fluorine group may be derived from an organic fluorine compound monomer. By mixing the core particle with a fluorine-containing precursor and heat-treating the resulting mixture, a fluorine group can be formed on the surface of the core particle, while simultaneously forming a hydrophobic surface layer containing the organic fluorine compound monomer.

[0095] That is, the hydrophobic surface layer may include an organic fluorine compound monomer together with a fluorine group derived from the organic fluorine compound monomer.

[0096] The types of the above organic fluorine compound monomers are as described above.

[0097] In one embodiment, the hydrophobic surface layer may comprise a silane compound.

[0098] The silane compound may include methyltrimethoxysilane, trimethylethoxysilane, trimethylchlorosilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropylmethyldiethoxysilane, a combination thereof, or a condensate thereof.

[0099] The above silane compound, when included within a predetermined range, can have the aforementioned contact angle for water, thereby achieving the purpose of the present disclosure.

[0100] With respect to 100 wt% of the core particles, the lower limit of the content of the silane compound may be about 5 wt%, 5.2 wt%, 5.4 wt%, 5.6 wt%, 5.8 wt%, 6 wt%, 6.2 wt%, 6.4 wt%, 6.6 wt%, 6.8 wt%, or 7 wt% or 7.2 wt%, and the upper limit may be about 30 wt%, 28 wt%, 26 wt%, 24 wt%, 22 wt%, 20 wt%, 18 wt%, 16 wt%, 14 wt%, 12 wt%, 10 wt%, or 8 wt%.

[0101] The silane compound may be included in a range that is equal to or greater than any one of the lower limits described above, or equal to or less than any one of the upper limits described above, based on 100 wt% of the core particles; or equal to or greater than any one of the lower limits described above and equal to or less than any one of the upper limits described above. When the content of the silane compound in the surface layer satisfies the above range, a contact angle with respect to water within the above range can be secured, thereby improving durability with respect to water, and at the same time, bonding with the side chain of the ion conductor can be increased, thereby improving performance and durability.

[0102] In another embodiment, the hydrophobic surface layer may comprise a hydrophobic polymer.

[0103] In this specification, the hydrophobic polymer excludes the condensate exemplified in the above silane compound.

[0104] The above hydrophobic polymer refers to a material that does not dissolve in water or other polar solvents, and may include, for example, an acrylic polymer, an epoxy polymer, a polyamide polymer, a polyethylene polymer, an EVC polymer, a polyester polymer, a PVC polymer, polyurethane, or a combination thereof.

[0105] Specifically, the hydrophobic polymer is polymethylmethacrylate, polycarbonate, polyurethane, tetrafluoroethylene, chlorotrifluoroethylene, vinylidenefluoride, vinylfluoride, hexafluoropropylene, perfluorovinylether, perfluoromethylvinylether, polyvinylidene fluoride, polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), polyvinylidenedifluoride (PVDF), fluorinated ethylene propylene copolymer (FEP), polyethylene-co-tetra fluoroethylene (ETFE). ethylene), polyethylene-chlorotrifluoroethylene (ECTFE, poly ethylene-co-chloro trifluoro ethylene), polytetrafluoroethylene-fluoro alkyl vinyl ether (PFA, poly tetra fluoro ethylene-co-fluoro alkyl vinyl ether), or combinations thereof.

[0106] The hydrophobic polymer, when included within a predetermined range, can have the aforementioned contact angle with respect to water, thereby achieving the purpose of the present disclosure.

[0107] With respect to 100 wt% of the core particles, the lower limit of the content of the hydrophobic polymer may be about 7 wt%, 7.5 wt%, 8 wt%, 8.5 wt%, 9 wt%, 9.5 wt% or 10 wt%, and the upper limit may be about 40 wt%, 35 wt%, 30 wt%, 25 wt%, 20 wt%, 18 wt%, 16 wt%, 14 wt%, 12 wt% or 10 wt%.

[0108] The hydrophobic polymer may be included in a range of at least one of the lower limits described above, or more than or more than the lower limit described above, or less than or less than the upper limit described above, or more than or more than the lower limit described above and less than or less than the upper limit described above, based on 100 wt% of the core particles. When the content of the hydrophobic polymer in the surface layer satisfies the range, a contact angle with respect to water within the range described above can be secured, thereby improving durability with respect to water, and at the same time, bonding with the side chain of the ion conductor can be increased, thereby improving performance and durability.

[0109] The above core particles may include a precious metal oxide.

[0110] For example, 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), osmium (Os), alloys thereof, or combinations thereof.

[0111] The above alloys may be, for example, Ir-Fe, Ir-Ru, Ir-Os, Co-Fe, Co-Ru, Co-Os, Rh-Fe, Rh-Ru, Rh-Os, Ir-Ru-Fe, Ir-Ru-Os, Rh-Ru-Fe, Rh-Ru-Os, or combinations thereof.

[0112] In one embodiment, the noble metal oxide is IrO x (wherein x is an integer from 1 to 3), RuO x (where x is an integer from 1 to 3), IrMO x (wherein M includes Ru, Sn, Ti, Te, Ta, Nb, Sb, Se, W, or a combination thereof, and x is an integer from 1 to 3), or may include a combination thereof.

[0113] More preferably, the noble metal oxide is IrO x (where x is an integer from 1 to 3), IrMO x (wherein M includes Ru, Sn, Ti, Te, Ta, Nb, Sb, Se, W, or a combination thereof, and x is an integer from 1 to 3) or a combination thereof, and more specifically, the IrMO x is IrRuO x It can be. The above noble metal oxide is ruthenium oxide (RuO x ) compared to iridium and ruthenium oxide (IrRuO x ) can improve durability, and iridium and ruthenium oxide (IrRuO x ) is iridium oxide (IrO x ) can perform equally well.

[0114] The content of the composite active particles may be 60 wt% or more with respect to 100 wt% of the oxygen generation reaction catalyst, for example, 60 wt% or more, 70 wt% or more, 80 wt% or more, or 90 wt% or more, and may be less than 100 wt%, 99.9 wt% or less, 90 wt% or less, 80 wt% or less, or 70 wt% or less. When the content of the composite active particles in the oxygen generation reaction catalyst satisfies the above range, performance and durability can be improved.

[0115] The oxygen generation reaction catalyst of the above electrolysis cell may further include a carrier that supports the composite active particles.

[0116] The carrier may be porous carbon, a conductive metal, a metal oxide, or a combination thereof.

[0117] The porous carbon may be activated carbon, carbon fiber, graphite fiber, graphene, or carbon nanotubes, the conductive metal may be tungsten, titanium, nickel, ruthenium, tantalum, tin, cobalt, niobium, or a combination thereof, and the metal oxide may be an oxide of metals including tungsten, titanium, nickel, ruthenium, tantalum, tin, cobalt, niobium, or a combination thereof.

[0118] For example, the carrier may be a metal oxide, for example titanium dioxide (TiO2) or tin dioxide (SnO2).

[0119] The carrier may be included in an amount of 10 to 200 parts by weight per 100 parts by weight of the composite active particles.

[0120]

[0121] 2. Membrane-electrode assembly for electrolysis cell

[0122] 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.

[0123] The membrane-electrode assembly for the above-described electrolysis cell is illustrated in FIG. 3. The membrane-electrode assembly (100) for the electrolysis cell according to FIG. 3 includes a polymer electrolyte membrane (30); an oxygen generation electrode (10) positioned on one side of the polymer electrolyte membrane; and a hydrogen generation electrode (20) positioned on the other side of the polymer electrolyte membrane.

[0124] The membrane-electrode assembly for the above-mentioned electrolysis cell can have excellent durability by including the above-mentioned oxygen evolution reaction catalyst.

[0125] For example, the durability of a membrane-electrode assembly can be expressed by a voltage increase rate. The voltage increase rate of the membrane-electrode assembly including the oxygen evolution reaction catalyst, as expressed by Equation 1 below, can be within a predetermined range. A specific method for measuring the voltage increase rate follows the method described in "Durability Evaluation" in Evaluation Example 3 of this specification.

[0126] [Formula 1]

[0127] Voltage increase rate (%) = (voltage after driving - initial voltage) / (initial voltage) × 100

[0128] The lower limit of the voltage increase rate may be about 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5% or 5.5%, and the upper limit may be about 7%, 6.5%, 6%, 5.5%, 5%, 4.5%, 4%, 3.5%, 3%, 2.5% or 2%.

[0129] The voltage increase rate of the membrane-electrode assembly may have a range that is less than or equal to any one of the upper limits described above; or greater than or exceeding any one of the lower limits described above, and less than or equal to any one of the upper limits described above.

[0130] Hereinafter, the oxygen generation electrode, the hydrogen generation electrode, and the polymer electrolyte membrane will be described in detail.

[0131] The above oxygen evolution electrode refers to an electrode where an oxygen evolution reaction (OER) occurs.

[0132] The above oxygen generation electrode includes a catalyst for the oxygen generation reaction of the water electrolysis cell.

[0133] The catalyst for the oxygen generation reaction of the above electrolysis cell is the same as that described in the item “1. Catalyst for the oxygen generation reaction of the electrolysis cell.”

[0134] The above oxygen generation electrode may contain an oxygen generation reaction catalyst within a predetermined range based on 100 wt% of the oxygen generation electrode. For example, the lower limit of the content of the oxygen generation reaction catalyst may be approximately 70 wt% or 72 wt%, and the upper limit may be approximately 98 wt% or 96 wt%.

[0135] The content of the catalyst for the oxygen generation reaction may be in a range of more than or exceeding any one of the lower limits described above; less than or equal to any one of the upper limits described above; or more than or exceeding any one of the lower limits described above and less than or equal to any one of the upper limits described above.

[0136] The above oxygen generation electrode may further include an ion conductor to improve the adhesion of the catalyst and transfer hydrogen ions.

[0137] The above ion conductor may include a cation exchanger to ensure ion conductivity.

[0138] 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.

[0139] The above ion conductor may be a fluorine-based ion conductor, a hydrocarbon-based ion conductor, or a mixture thereof.

[0140] 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, for example, poly(perfluorosulfonic acid), poly(perfluorocarboxylic acid), etc.

[0141] 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, sulfonated polyarylene ether, sulfonated polyarylene ether nitrile, sulfonated polyarylene ether ether nitrile,It may be polyarylene ether sulfone ketone, etc.

[0142] According to one embodiment, the ion conductor may have hydrogen ion conductivity.

[0143] The ion conductor having the above hydrogen ion conductivity can also substitute H with Na, K, Li, Cs or tetrabutylammonium in the cation exchanger at the end of the side chain. When substituting H 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 substituting H with tetrabutylammonium, tetrabutylammonium hydroxide is used. K, Li or Cs can also be substituted using an appropriate compound. Since this substitution method is widely known in the art, a detailed description thereof will be omitted herein.

[0144] The content of the ion conductor can be appropriately adjusted as needed. In one example, the lower limit of the content of the ion conductor relative to 100 parts by weight of the oxygen generation reaction catalyst can be about 2 parts by weight or 4 parts by weight, and the upper limit can be about 30 parts by weight or 28 parts by weight.

[0145] The ion conductor may have a range of at least or exceeding any one of the lower limits described above, relative to 100 parts by weight of the oxygen evolution reaction catalyst; or at most or exceeding any one of the upper limits described above, or at most or exceeding any one of the lower limits described above, and at most or less than any one of the upper limits described above. When the ion conductor is within the above range, the performance and durability are excellent.

[0146] The above ion conductor can be used as a single substance or as a mixture, and may also be optionally used together with a non-conductive compound for the purpose of further improving adhesion to the polymer electrolyte membrane. The content of the non-conductive compound can be appropriately adjusted depending on the intended use.

[0147] As the above 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.

[0148] The above hydrogen generation electrode refers to an electrode where a hydrogen evolution reaction (Hydrogen Evolution Reaction (HER)) occurs.

[0149] The above hydrogen generation electrode may include a catalyst for hydrogen generation reaction. The catalyst for hydrogen generation reaction may include active particles and a carrier.

[0150] The above active particles may include a precious metal.

[0151] For example, the precious metal may be a platinum-based precious metal.

[0152] 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).

[0153] 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.

[0154] The above carrier may be a carbon-based carrier.

[0155] 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.

[0156] The above oxygen generation electrode and the above hydrogen generation electrode may each include only a catalyst layer including an oxygen generation reaction catalyst and a hydrogen generation reaction catalyst, but may include an electrode substrate together with the catalyst layer.

[0157] At this time, the electrode substrate can play a role in supporting the electrode and diffusing the fuel and oxidant to the catalyst layer.

[0158] The electrode substrate may include a microporous layer, a porous diffusion layer, or a combination thereof.

[0159] The above microporous layer serves to enhance the diffusion effect of the reactant, and may generally include a conductive powder having a small particle size, for example, carbon powder, carbon black, acetylene black, activated carbon, metal oxide nanowire, carbon fiber, fullerene, carbon nanotube, carbon nanowire, carbon nano-horn, or carbon nano ring.

[0160] The above porous diffusion layer is made of porous titanium, carbon paper, carbon cloth, carbon felt or metal cloth (a porous film made of metal cloth in a fibrous state or a metal film formed on the surface of a cloth formed of polymer fibers).

[0161] The above microporous layer and the above porous diffusion layer may include known materials in addition to those exemplified above.

[0162] The above electrode substrate can be treated with a water-repellent fluorine resin, in which case the diffusion efficiency of reactants can be prevented from being reduced by water generated during operation of the electrolysis cell.

[0163] 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.

[0164] The above electrode substrate can improve conductivity by using platinum or the like and prevent corrosion of the porous diffusion layer by an ion conductor, thereby preventing deterioration of electrolysis performance.

[0165] The above polymer electrolyte membrane has an ion exchange function that moves hydrogen ions generated at an oxygen generation electrode to a catalyst for hydrogen generation reaction.

[0166] A polymer electrolyte membrane according to one embodiment may include a porous support including a plurality of pores, and an ion conductor filling the pores of the porous support.

[0167] The above porous support may be a fluorine-based support or a nano web support.

[0168] The fluorine-based 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.

[0169] 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.

[0170] The above ion conductor is as described above.

[0171] 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.

[0172]

[0173] 3. Susan Hae-cell

[0174] In one embodiment, the electrolysis cell comprises a membrane-electrode assembly for the electrolysis cell.

[0175] 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.

[0176] Hereinafter, embodiments of the present disclosure will be described in detail so that those skilled in the art can easily implement the present disclosure. However, the present disclosure may be implemented in various different forms and is not limited to the embodiments described herein.

[0177] Example 1

[0178] As a catalyst for the oxygen evolution reaction of a water electrolysis cell, 0.5 g of IrO2 (Alfa Aesar, 43396) was placed in a reaction vessel, and then a plasma treatment process was performed for 10 seconds under the conditions of 5°C and 800 W with 10% tetrafluoromethane (CF4) gas, a fluorine-containing gas, at a flow rate of 30 sccm to produce a composite active particle having a hydrophobic surface containing a fluorine group formed on the surface of IrO2 as a core particle.

[0179] At this time, the fluorine group in the composite active particle was included at 7 wt% with respect to 100 wt% of the core particle.

[0180]

[0181] Example 2

[0182] As a catalyst for the oxygen evolution reaction of the electrolysis cell, 0.5 g of IrO2 (Alfa Aesar, 43396) was placed in a reaction vessel, and then 0.1 g of NH4F was added as a fluorine-containing precursor. Then, a mixture was prepared by stirring the mixture for 5 minutes at a frequency of 60 Hz using a Resonant Acoustic Mixer (RAM) while applying a gravitational acceleration of 80 g. The mixture was heat-treated for 3 hours at a temperature of 200 ℃ in a nitrogen atmosphere using a tube furnace to prepare composite active particles having a hydrophobic surface including a fluorine group formed on the surface of IrO2 as a core particle.

[0183] At this time, the fluorine group in the composite active particle was included at 7 wt% with respect to 100 wt% of the core particle.

[0184]

[0185] Example 3

[0186] As a catalyst for the oxygen evolution reaction of a water electrolysis cell, 0.5 g of IrO2 (Alfa Aesar, 43396) was placed in a reaction vessel, and 100 ml of ethanol as a solvent and 0.5 g of 3-aminopropyltriethoxysilane from Sigma-Aldrich as a silane compound were added. The mixture was mixed using a homogeneous mixer in an atmosphere with a frequency of 60 Hz and a gravitational acceleration of 80 g for 5 minutes to perform a hydrolysis / condensation reaction, thereby manufacturing a composite active particle having a hydrophobic surface layer including a silane compound formed on the surface of IrO2 as a core particle.

[0187] At this time, the silane compound was included at 7 wt% with respect to 100 wt% of the core particles, the area of ​​the hydrophobic surface layer was approximately 85% of the total surface area of ​​the composite active particles, and the thickness of the hydrophobic surface layer was approximately 3 nm.

[0188]

[0189] Example 4

[0190] As a catalyst for the oxygen evolution reaction of a water electrolysis cell, 0.5 g of IrO2 (Alfa Aesar, 43396) was placed in a reaction vessel, 0.1 g of polyurethane (Sigma-Aldrich, Polyurethane solution) was added, and mixed using a homogeneous mixer to produce composite active particles in which a hydrophobic surface layer including polyurethane was formed on the surface of IrO2 as a core particle.

[0191] At this time, the hydrophobic polymer is the core particle It was included at 10 wt% with respect to 100 wt%, the area of ​​the hydrophobic surface layer was about 75% of the total surface area of ​​the composite active particle, and the thickness of the hydrophobic surface layer was about 5 nm.

[0192]

[0193] Comparative example

[0194] As a catalyst for the oxygen evolution reaction in the electrolysis cell, IrO2 (Alfa Aesar, 43396) was used alone without any separate surface treatment.

[0195]

[0196] Evaluation Example 1. Measurement of contact angle with water

[0197] The oxygen generation reaction catalysts of the electrolysis cells manufactured in Examples 1 to 4 and Comparative Examples were placed in an IR pellet manufacturing vessel and pressurized at 1,000 psi to manufacture pellets having a thickness of 400 μm and a diameter of 13 mm. Using a Theta Flex device from Biolin, 5 μL of water was dropped on the pellets at a rate of 1 μl / sec, and the contact angle with water was measured according to the tangent angle measurement method. The results at this time are shown in Table 1 and Fig. 4 below.

[0198] Contact angle for water (°) Example 1 11 14.5 Example 2 100 Example 3 130 Example 4 15 2.5 Comparative Example 18

[0199]

[0200] Evaluation Example 2. IV Characteristics

[0201] An electrode slurry was prepared by adding 20 parts by weight of an ion conductor dispersion and a solvent to 100 parts by weight of the oxygen generation reaction catalyst of the electrolysis cell manufactured in Examples 1 to 4 and Comparative Examples, and the electrode slurry was directly coated on a polymer electrolyte membrane (Chemours, NR212) and then dried at 90°C for 30 minutes to prepare a membrane-electrode assembly for an electrolysis cell.

[0202] The membrane-electrode assembly for the electrolysis cell manufactured above was applied inside a unit cell designed and manufactured for the electrolysis cell, and the voltage and resistance were measured at specific currents from 1 mA to 20 A under conditions of cell temperature 80 ℃, water temperature 80 ℃, and flow rate 5 ml / min, using a protocol for measuring the voltage and resistance, and the measurement was stopped at 2 V.

[0203] The result at this time is as shown in Fig. 5.

[0204]

[0205] Evaluation Example 3. Durability Evaluation

[0206] A membrane-electrode assembly was manufactured in the same manner as in Evaluation Example 2, and the manufactured membrane-electrode assembly was applied inside a unit cell designed and manufactured for a water electrolysis cell, and the activated cell was activated at a cell temperature of 80°C and a current density of 1 A / cm. 2 The initial voltage was measured under the conditions of cell temperature 80 ℃, current density 1 A / cm 2 After driving the constant current for 500 hours, the voltage was measured.

[0207] The above voltage was measured using a potentiostat from BioLogic, and the voltage increase rate was calculated using the measured voltage according to Equation 1 below. The results at this time are as shown in Table 2 below.

[0208] [Formula 1]

[0209] Voltage increase rate (%) = (voltage after operation - initial voltage) / (initial voltage) × 100

[0210] Voltage increase rate (%) Example 11.6 Example 21.7 Example 33.3 Example 45.5 Comparative example 8.2

[0211]

[0212] result

[0213] According to FIG. 4, it can be confirmed that the contact angle for water of the oxygen evolution reaction catalysts of Examples 1 to 4, in which the surface of the core particle was modified to be hydrophobic, is larger than that of the oxygen evolution reaction catalysts of the comparative examples, in which this was not done.

[0214] According to FIG. 5, it can be confirmed that the membrane-electrode assembly including the oxygen evolution reaction catalyst of Examples 1 to 4, in which the surface of the core particle is hydrophobically modified, exhibits improved performance by showing a higher current density at the same voltage compared to the comparative example in which this is not the case.

[0215] In addition, according to Table 2, it can be confirmed that the membrane-electrode assembly including the oxygen evolution reaction catalyst of Examples 1 to 4, in which the surface of the core particle was modified to be hydrophobic, has a significantly lower voltage increase rate compared to the comparative example in which this was not done, and thus has improved durability.

[0216]

[0217] Although the preferred embodiments of the present disclosure have been described in detail above, the scope of the present disclosure is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concepts of the present disclosure defined in the following claims also fall within the scope of the present disclosure.

[0218] [Explanation of symbols]

[0219] 1: Core particle

[0220] 2: Hydrophobic surface layer

[0221] 3: Composite active particles

[0222] A: Hydrophobic surface

[0223] 100: Membrane-electrode assembly for electrolysis cell

[0224] 10: Oxygen generation electrode

[0225] 20: Hydrogen generation electrode

[0226] 30: Polymer electrolyte membrane

Claims

1. Containing a core particle containing a precious metal oxide, Comprising a composite active particle having a hydrophobic surface comprising a fluorine group, a silane compound, a hydrophobic polymer or a combination thereof; Catalyst for oxygen evolution reaction in a water electrolysis cell.

2. In paragraph 1, The above composite active particles have a contact angle with water within the range of 25° to 200°. Catalyst for oxygen evolution reaction in a water electrolysis cell.

3. In paragraph 1, The above precious metal oxide is IrO x (wherein x is an integer from 1 to 3), RuO x (where x is an integer from 1 to 3), IrMO x (wherein M comprises Ru, Sn, Ti, Te, Ta, Nb, Sb, Se, W, or a combination thereof, and x is an integer from 1 to 3), or a combination thereof, Catalyst for oxygen evolution reaction in a water electrolysis cell.

4. In paragraph 1, The above composite active particles are Containing the fluorine group in a range of 3 wt% to 20 wt% with respect to 100 wt% of the core particles, Catalyst for oxygen evolution reaction in a water electrolysis cell.

5. In paragraph 1, The above composite active particle further comprises a hydrophobic surface layer positioned on the core particle, The hydrophobic surface layer comprises the fluorine group, the silane compound, the hydrophobic polymer, or a combination thereof. Catalyst for oxygen evolution reaction in a water electrolysis cell.

6. In paragraph 5, The area of ​​the hydrophobic surface layer of the above composite active particles is Within a range of 50% to 100% of the total surface area of ​​the core particle, Catalyst for oxygen evolution reaction in a water electrolysis cell.

7. In paragraph 5, The thickness of the hydrophobic surface layer is 1 nm to 8 nm. Catalyst for oxygen evolution reaction in a water electrolysis cell.

8. In paragraph 5, The above fluorine group is derived from an organic fluorine compound, The hydrophobic surface layer including the above fluorine group further includes an organic fluorine compound. Catalyst for oxygen evolution reaction in electrolysis cells.

9. In paragraph 5, The above silane compound is A compound comprising methyltrimethoxysilane, trimethylethoxysilane, trimethylchlorosilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropylmethyldiethoxysilane, a combination thereof, or a condensate thereof. Catalyst for oxygen evolution reaction in a water electrolysis cell.

10. In paragraph 5, The above composite active particles are With respect to 100 wt% of the core particles, the silane compound is included in a range of 5 wt% to 30 wt%. Catalyst for oxygen evolution reaction in a water electrolysis cell.

11. In paragraph 5, The hydrophobic polymer includes an acrylic polymer, an epoxy polymer, a polyamide polymer, a polyethylene polymer, an EVC polymer, a polyester polymer, a PVC polymer, a polyurethane, or a combination thereof. Catalyst for oxygen evolution reaction in a water electrolysis cell.

12. In paragraph 5, The above composite active particles are With respect to 100 wt% of the core particles, the hydrophobic polymer is included in a range of 7 wt% to 40 wt%. Catalyst for oxygen evolution reaction in a water electrolysis cell.

13. In paragraph 1, The content of the above composite active particles is 60 wt% or more with respect to 100 wt% of the oxygen generation reaction catalyst. Catalyst for oxygen evolution reaction in electrolysis cells.

14. In paragraph 1, Further comprising a carrier carrying the above composite active particles, The above carrier comprises a metal oxide, Catalyst for oxygen evolution reaction in a water electrolysis cell.

15. In paragraph 14, The carrier is included in an amount of 10 to 200 parts by weight per 100 parts by weight of the composite active particles. Catalyst for oxygen evolution reaction in a water electrolysis cell.

16. Polymer electrolyte membrane; An oxygen generation electrode positioned on one side of the polymer electrolyte membrane and including a catalyst for oxygen generation reaction of the water electrolysis cell according to claim 1; and A hydrogen generation electrode positioned on the other side of the polymer electrolyte membrane; Membrane-electrode assembly for a water electrolysis cell.

17. In paragraph 16, The voltage increase rate expressed by Equation 1 below is 7% or less, Membrane-electrode assembly for water electrolysis cell: [Formula 1] Voltage increase rate (%) = (voltage after driving - initial voltage) / (initial voltage) × 100 18. A water electrolysis cell comprising a membrane electrode assembly according to claim 17.

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