Catalyst for oxygen evolution reaction of water electrolysis cell, manufacturing method therefor, membrane-electrode assembly for water electrolysis cell including same, and water electrolysis cell

Abstract

The present disclosure relates to a catalyst for an oxygen evolution reaction of a water electrolysis cell, a manufacturing method therefor, a membrane-electrode assembly for a water electrolysis cell including same, and a water electrolysis cell. The catalyst for the oxygen evolution reaction of a water electrolysis cell includes a heterogeneous noble metal composite which has a nanowire shape and includes different first and second noble metal oxides in a node structure, whereby the catalyst can reduce the amount of the noble metals used while improving performance and can enhance performance and durability depending on the types and lengths of the noble metals forming the heterogeneous noble metal composite.

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 disclosure relates to a catalyst for an oxygen evolution reaction in a water electrolysis cell and a method for producing the same, and a membrane-electrode assembly for an electrolysis cell and an electrolysis cell including the same, and more particularly, to a catalyst for an oxygen evolution reaction in a water electrolysis cell and a method for producing the same, and a membrane-electrode assembly for an electrolysis cell including the same, and a electrolysis cell including the same, wherein the amount of precious metal used is reduced while the performance is improved by including a heterogeneous precious metal complex having a nanowire shape including different first and second precious metal oxides, and the performance and durability are improved according to the type and length of the precious metals forming the heterogeneous precious metal complex.

[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, and among these, hydrogen is attracting attention as a raw material for renewable energy.

[0004] Hydrogen energy is classified into gray, blue, and green hydrogen depending on the production method. Gray and blue hydrogen have the problem that carbon dioxide is generated during the production process or cannot be completely removed because they use fossil fuels.

[0005] 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.

[0006] 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.

[0007] This technology relates to a catalyst for electrolysis, particularly a catalyst for an oxygen evolution electrode of a polymer electrolyte membrane (PEM) electrolysis. Conventionally, iridium black and iridium oxide powder have been used as catalysts for oxygen evolution reactions in PEM electrolysis oxygen evolution electrodes, but improvements are required for their low dispersibility, low electrical conductivity, and instability.

[0008] Additionally, there is a need to reduce the use of iridium due to the high price of iridium raw materials.

[0009] According to one embodiment, a catalyst for an oxygen evolution reaction of a water electrolysis cell is provided, which includes a heterogeneous precious metal complex having a nanowire shape including different first and second precious metal oxides, thereby improving performance while reducing the amount of precious metal used, and improving performance and durability according to the type and length of precious metals forming the heterogeneous precious metal complex.

[0010] According to another embodiment, a method for producing a catalyst for oxygen generation reaction of the above-described electrolysis cell is provided.

[0011] According to another embodiment, a membrane-electrode assembly and a water electrolysis cell are provided, including an oxygen generation electrode including a catalyst for an oxygen generation reaction of the water electrolysis cell.

[0012] A catalyst for an oxygen generation reaction in an electrolytic cell according to one embodiment includes a heterogeneous precious metal complex including a first precious metal oxide and a second precious metal oxide different from the first precious metal oxide, and the heterogeneous precious metal complex has a nanowire shape.

[0013] The above first noble metal oxide is IrO x (x can be an integer from 1 to 3).

[0014] The above second precious metal oxide is MO x (The above M may include Ru, Pt, Sn, Se, Sb, Ta, Te, Nb, W, Zn, Au, or a combination thereof, and the above x may be an integer from 1 to 3).

[0015] The length of the above nanowire may be in the range of 100 nm to 1,000 nm.

[0016] The above first precious metal oxide may be included in a range of 10 wt% to 90 wt% relative to the total weight of the heterogeneous precious metal complex.

[0017] In the above heterogeneous precious metal complex, the weight ratio of the first precious metal oxide and the second precious metal oxide may be within the range of 1:9 to 9:1.

[0018] The above heterogeneous precious metal complex includes a first precious metal oxide layer including the first precious metal oxide, and a second precious metal oxide layer including the second precious metal oxide.

[0019] The above heterogeneous precious metal complex may have the first precious metal oxide layer and the second precious metal oxide layer alternately arranged in the longitudinal direction of the nanowire.

[0020] The first noble metal oxide layer and the second noble metal oxide layer are each independently the minimum repeating unit, and the heterogeneous noble metal complex may have two or more repeating units of the first noble metal oxide layer and one or more repeating units of the second noble metal oxide layer.

[0021] The above heterogeneous precious metal complex may include 2 to 10 layers of the first precious metal oxide and 1 to 9 layers of the second precious metal oxide.

[0022] The length of the first noble metal oxide layer may be in a range of 10 nm or more and less than 1,000 nm, and the length of the second noble metal oxide layer may be in a range of 10 nm or more and less than 1,000 nm.

[0023] The ratio of the length of the first noble metal oxide layer to the length of the second noble metal oxide layer may be within a range of 1:0.1 to 1:10.

[0024] A method for manufacturing a catalyst for an oxygen generation reaction of a water electrolysis cell according to another embodiment includes a step (S1) of injecting a precursor of a first noble metal oxide to fill a portion of a mold and performing an electroplating process; and a step (S2) of injecting a precursor of a second noble metal oxide different from the precursor of the first noble metal oxide to fill a portion of the mold and performing an electroplating process; wherein step S1, step S2, or both of these steps are repeated n times (wherein n is a natural number greater than or equal to 1).

[0025] The above mold is an anodic aluminum oxide membrane (AAO) including a substrate and a plurality of pores penetrating the substrate in the thickness direction, and the precursor of the first noble metal oxide and the precursor of the second noble metal oxide can be alternately filled in the pores.

[0026] The above electroplating process is 0.05 mA / cm 2 2.0 mA / cm 2 It can be performed for 10 to 300 minutes under current within the range.

[0027] The method may further include a step (S3) of removing the mold after repeating the above steps S1 and S2 n times (where n is a natural number greater than or equal to 1); and a step (S4) of performing a heat treatment process to form a heterogeneous precious metal complex including a first precious metal oxide and a second precious metal oxide different from the first precious metal oxide.

[0028] The above S3 step can utilize an alkaline solution.

[0029] 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.

[0030] The above membrane-electrode assembly has a current density of 2.0 A / cm measured at 1.7 V under conditions of cell temperature 80°C, water temperature 80°C, and flow rate 5 ml / min. 2 It could be strange.

[0031] According to another embodiment, a hydroelectric cell comprises the membrane-electrode assembly.

[0032] According to one embodiment, a catalyst for an oxygen generation reaction of a water electrolysis cell includes a heterogeneous precious metal complex having a nanowire shape including different first and second precious metal oxides in a node structure, thereby reducing the amount of precious metal used while improving performance, and performance and durability can be improved depending on the type and length of precious metals forming the heterogeneous precious metal complex.

[0033] Figure 1 is a schematic diagram showing a manufacturing process of a catalyst for oxygen generation reaction in a water electrolysis cell according to one embodiment.

[0034] Figures 2 and 3 are optical microscope photographs of the oxygen generation reaction catalyst of the electrolysis cell manufactured in Examples 1-1 and 2-1, respectively.

[0035] Figure 4 is a scanning electron microscope (SEM) photograph of the oxygen evolution reaction catalyst of the electrolysis cell manufactured in Comparative Example 1.

[0036] FIG. 5 is a schematic diagram showing a membrane-electrode assembly (MEA) for a water electrolysis cell according to one embodiment.

[0037] Figure 6 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 1-1, 2-1, 3, 4 and Comparative Example 1.

[0038] 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.

[0039] As used herein, “combination thereof” means a mixture, laminate, composite, copolymer, alloy, blend, reaction product, etc. of the components.

[0040] 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.

[0041] In this specification, terms are used solely to distinguish one component from another. Singular expressions include plural expressions unless the context clearly indicates otherwise.

[0042] 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.

[0043] 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.).

[0044] 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).

[0045] Unless otherwise defined herein, “alkoxy group” means an alkyl group linked through oxygen, for example, methoxy, ethoxy, and sec-butyloxy groups.

[0046] In this specification, the indications S1, S2, S3,…, Sn, etc. are for convenience only to refer to each step, and do not mean that each step proceeds in a chronological order or that no other additional steps are included between each step.

[0047]

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

[0049] A catalyst for an oxygen generation reaction in an electrolytic cell according to one embodiment includes a heterogeneous precious metal complex including a first precious metal oxide and a second precious metal oxide different from the first precious metal oxide, and the heterogeneous precious metal complex has a nanowire shape.

[0050] In this specification, “first” and “second” are only indicated as “first” and “second” to identify different types of precious metal oxides, and do not indicate the priority among the precious metal oxides.

[0051] The performance and durability of the oxygen generation reaction catalyst of the above electrolysis cell can be improved depending on the length of the nanowire and the types of the first noble metal oxide and the second noble metal oxide.

[0052] The length of the above nanowire may be within a predetermined range. A specific method for measuring the length of the above nanowire is to photograph the nanowire using a scanning electron microscope (SEM) and measure the length of the nanowire.

[0053] For example, the lower limit of the length of the nanowire may be about 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, or 800 nm, and the upper limit may be about 1,000 nm, 900 nm, 800 nm, 700 nm, 600 nm, 500 nm, 400 nm, or 300 nm.

[0054] The length of the nanowire may be 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.

[0055] In addition, the first noble metal oxide is IrO x (where x is an integer from 1 to 3) may be iridium oxide.

[0056] The second noble metal oxide may be a noble metal oxide other than iridium oxide, which is the first noble metal oxide. For example, the second noble metal oxide may be MO x (The above M may include Ru, Pt, Sn, Se, Sb, Ta, Te, Nb, W, Zn, Au, or a combination thereof, and the above x may be an integer from 1 to 3).

[0057] By including the above heterogeneous precious metal complex, it is possible to provide a catalyst for oxygen evolution reaction of a water electrolysis cell that improves performance and durability while reducing the amount of precious metal, particularly iridium, used.

[0058] The above first precious metal oxide may be included within a predetermined range relative to the total weight of the heterogeneous precious metal complex of the electrolytic cell.

[0059] For example, the lower limit of the content of the first precious metal oxide may be about 10 wt%, 20 wt%, 30 wt%, 40 wt%, 50 wt%, 60 wt%, 70 wt%, or 80 wt%, and the upper limit may be about 90 wt%, 80 wt%, 70 wt%, 60 wt%, 50 wt%, 40 wt%, 30 wt%, or 20 wt%.

[0060] The above first precious metal oxide may have a range of at least or exceeding any one of the lower limits described above, or at most or less than 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, relative to the total weight of the heterogeneous precious metal complex.

[0061] In the above heterogeneous precious metal complex, the weight ratio of the first precious metal oxide and the second precious metal oxide may be within a range of 1:9 to 9:1.

[0062] For example, the weight ratio of the first noble metal oxide and the second noble metal oxide may be 1:9, 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2, or 9:1.

[0063] For example, the hetero-precious metal composite may include a first precious metal oxide layer including the first precious metal oxide, and a second precious metal oxide layer including the second precious metal oxide. The first precious metal oxide layer may not include any other component other than the first precious metal oxide. That is, the first precious metal oxide layer may be made of the first precious metal oxide. In addition, the second precious metal oxide layer may not include any other component other than the second precious metal oxide. That is, the second precious metal oxide layer may be made of the second precious metal oxide.

[0064] The above heterogeneous precious metal complex may be one in which the first precious metal oxide layer and the second precious metal oxide layer are alternately arranged in the longitudinal direction of the nanowire. The meaning of the first precious metal oxide layer and the second precious metal oxide layer being alternately arranged may mean, for example, a structure in which the first precious metal oxide layer - the second precious metal oxide layer - the first precious metal oxide layer are alternately arranged.

[0065] Here, the first noble metal oxide layer and the second noble metal oxide layer are each independently in the form of layers and are the minimum repeating units in the heterogeneous noble metal complex, and the heterogeneous noble metal complex may have repeating units of two or more of the first noble metal oxide layers and may have repeating units of one or more of the second noble metal oxide layers.

[0066] Below, the first precious metal oxide layer and the second precious metal oxide layer, which are the minimum repeating units within the heterogeneous precious metal composite, are described in detail. It should be understood that the descriptions of the first precious metal oxide layer and the second precious metal oxide layer below are based on the minimum repeating units, and do not cover the entire first precious metal oxide layer or the entire second precious metal oxide layer within the heterogeneous precious metal composite.

[0067] For example, in the heterogeneous precious metal complex, the lower limit of the number of the first precious metal oxide layers may be about 2, 3, 4, 5, 6, 7, 8, or 9, and the upper limit may be about 10, 9, 8, 7, 6, 5, 4, or 3.

[0068] Additionally, within the heterogeneous precious metal complex, the lower limit of the number of the second precious metal oxide layers may be about 1, 2, 3, 4, 5, 6, 7, 8, or 9, and the upper limit may be about 9, 8, 7, 6, 5, 4, 3, or 2.

[0069] The number of the first noble metal oxide layer and the number of the second noble metal oxide layer may each be equal to or greater than any one of the lower limits described above; equal to or less than any one of the upper limits described above; 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.

[0070] The length of the first noble metal oxide layer or the length of the second noble metal oxide layer may be within a predetermined range. A specific method for measuring the length of the first noble metal oxide layer or the length of the second noble metal oxide layer is to photograph the nanowire using a scanning electron microscope (SEM) and measure the length of the first noble metal oxide layer or the length of the second noble metal oxide layer.

[0071] For example, the lower limit of the length of the first noble metal oxide layer or the length of the second noble metal oxide layer may be about 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm or 80 nm, and the upper limit may be about 100 nm, 90 nm, 80 nm, 70 nm, 60 nm, 50 nm, 40 nm or 30 nm.

[0072] The length of the first noble metal oxide layer or the length of the second noble metal oxide layer may be 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. In this case, it may be assumed that the length of the first noble metal oxide layer or the length of the second noble metal oxide layer is less than 100.

[0073] At this time, the ratio of the length of the first noble metal oxide layer to the length of the second noble metal oxide layer may be 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, or 1:10.

[0074] It is possible to provide a catalyst for oxygen generation reaction of a water electrolysis cell having improved performance and durability while including the first noble metal oxide and the second noble metal oxide within the above range.

[0075] The catalyst for the oxygen generation reaction of the above-mentioned electrolysis cell can achieve the purpose of the present disclosure if it includes the above-mentioned heterogeneous precious metal complex. If it includes the above-mentioned heterogeneous precious metal complex, it may further include other components.

[0076]

[0077] 2. Method for manufacturing a catalyst for oxygen generation reaction in a water electrolysis cell

[0078] A method for manufacturing an oxygen generation reaction catalyst of an electrolysis cell according to one embodiment includes a step (S1) of injecting a precursor of a first noble metal oxide to fill a portion of a mold and performing an electroplating process; and a step (S2) of injecting a precursor of a second noble metal oxide different from the precursor of the first noble metal oxide to fill a portion of the mold and performing an electroplating process; wherein steps S1 and S2 are repeated n times (n is a natural number greater than or equal to 1).

[0079] The method for manufacturing a catalyst for oxygen generation reaction of the above electrolysis cell is explained with reference to Figure 1.

[0080] The type of the above mold is not limited as long as it can form nanowires. For example, the above mold may be a polycarbonate membrane, a nylon membrane, a cellulose membrane, or an anodic aluminum oxide membrane (AAO).

[0081] In one embodiment, the mold may be an anodic aluminum oxide membrane (AAO membrane).

[0082] As illustrated in FIG. 1, the AAO film may include a substrate and a plurality of pores penetrating the substrate in the thickness direction. In FIG. 1, only seven pores are illustrated, but the number of pores may be adjusted as needed.

[0083] The diameter and length of the above pores can be within a predetermined range. The length of the pores is equal to the thickness of the AAO film. The method for measuring the diameter and length of the pores was to photograph the AAO film using a scanning electron microscope (SEM) and measure the diameter and length of the pores of the AAO film.

[0084] The lower limit of the diameter of the above pores may be about 10 nm or 15 nm, and the upper limit of the diameter may be about 200 nm or 190 nm. The diameter of the above pores may 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.

[0085] The lower limit of the length of the above pores may be about 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm or 900 nm, and the upper limit of the length may be about 1,500 nm, 1,400 nm, 1,300 nm, 1,200 nm, 1,100 nm, 1,000 nm or 900 nm.

[0086] The process of alternately injecting a precursor of a first noble metal oxide and a precursor of a second noble metal oxide into each pore of the AAO film is illustrated in FIG. 1. That is, the precursor of the first noble metal oxide and the precursor of the second noble metal oxide are alternately layered in each pore of the AAO film, and thereby, as described below, a catalyst for an oxygen evolution reaction of a water electrolysis cell having a structure in which the first noble metal oxide and the second noble metal oxide are alternately arranged in the longitudinal direction of a nanowire can be manufactured. The precursor of the first noble metal oxide refers to a material in a previous stage of the first noble metal oxide, which is the final product. As described above, "first" and "second" are merely indicated as "first" and "second", respectively, to identify different types of precursors of noble metal oxides, and do not indicate a priority between the precursors of the noble metal oxides.

[0087] The precursor of the above first noble metal oxide is not limited in type as long as it can produce iridium oxide.

[0088] For example, the precursor of the first noble metal oxide may include iridium (Ir) chloride, iridium acetate, iridium amine, or a combination thereof.

[0089] According to one embodiment, the first noble metal oxide precursor may be iridium (Ir) chloride, for example, IrCl4.

[0090] The above second noble metal oxide precursor refers to a material that is a precursor to the second noble metal oxide, which is the final product. The precursor of the second noble metal oxide is different from the precursor of the first noble metal oxide.

[0091] The precursor of the above second noble metal oxide is not limited in type as long as it produces an oxide of a noble metal other than iridium.

[0092] Precious metals other than the above iridium may be Ru, Pt, Sn, Se, Sb, Ta, Te, Nb, W, Zn, Au, or a combination thereof.

[0093] The precursor of the second noble metal oxide may include a chloride, acetate, amine, or combination thereof of a noble metal including Ru, Pt, Sn, Se, Sb, Ta, Te, Nb, W, Zn, Au, or a combination thereof.

[0094] For example, the precursor of the second noble metal oxide may be a chloride of a noble metal including Ru, Pt, Sn, Se, Sb, Ta, Te, Nb, W, Zn, Au, or a combination thereof, for example, RuCl4, SnCl4, NbCl4, or WCl4.

[0095] According to one embodiment, a catalyst for an oxygen evolution reaction in a water electrolysis cell comprises a precursor of the second noble metal oxide different from the precursor of the first noble metal oxide, thereby reducing the amount of noble metal, particularly iridium (Ir), used, and thereby improving performance. In addition, according to the embodiments and comparative examples of the present disclosure, it can be confirmed that performance is improved when different metals are used compared to when a single metal is used.

[0096] In the above step S1, a weak reducing agent may be further added together with the precursor of the first noble metal oxide, and / or in the above step S2, a weak reducing agent may be further added together with the precursor of the second noble metal oxide.

[0097] The above reducing agent may include formaldehyde, formic acid, oxalic acid, ascorbic acid, citric acid, urea, ethylenediamine, hexamethylenetetramine, or a combination thereof.

[0098] The amount of the reducing agent added in the above S1 step can be appropriately controlled. For example, in the S1 step, the reducing agent can be included in a weight part within a predetermined range relative to 100 weight parts of the precursor of the first noble metal oxide.

[0099] The lower limit of the content of the weak reducing agent relative to 100 parts by weight of the precursor of the first noble metal oxide may be about 200 parts by weight, 210 parts by weight, 220 parts by weight, 230 parts by weight, 240 parts by weight, 250 parts by weight, 260 parts by weight, 270 parts by weight, 280 parts by weight, or 285 parts by weight, and the upper limit may be about 400 parts by weight, 390 parts by weight, 380 parts by weight, 370 parts by weight, 360 parts by weight, 350 parts by weight, 340 parts by weight, 330 parts by weight, 320 parts by weight, 310 parts by weight, 300 parts by weight, 290 parts by weight, or 285 parts by weight.

[0100] The content of the above-described reducing agent may be in a range of more than or exceeding any one of the lower limits described above, or 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, relative to 100 parts by weight of the precursor of the first precious metal oxide.

[0101] Even in the above step S2, the amount of the reducing agent added can be appropriately controlled. For example, in the above step S2, the reducing agent can be included in a weight part within a predetermined range relative to 100 weight parts of the precursor of the second noble metal oxide.

[0102] The lower limit of the content of the weak reducing agent relative to 100 parts by weight of the precursor of the second noble metal oxide may be about 200 parts by weight, 210 parts by weight, 220 parts by weight, 230 parts by weight, 240 parts by weight, 250 parts by weight, 260 parts by weight, 270 parts by weight, 280 parts by weight, or 285 parts by weight, and the upper limit may be about 400 parts by weight, 390 parts by weight, 380 parts by weight, 370 parts by weight, 360 parts by weight, 350 parts by weight, 340 parts by weight, 330 parts by weight, 320 parts by weight, 310 parts by weight, 300 parts by weight, 290 parts by weight, or 285 parts by weight.

[0103] The content of the above-mentioned reducing agent may be in a range of more than or exceeding any one of the lower limits described above, or less than or equal to any one of the upper limits described above, relative to 100 parts by weight of the precursor of the second noble metal oxide, 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.

[0104] By performing an electroplating process on the precursor of the first noble metal oxide and the precursor of the second noble metal oxide in the above steps S1 and S2, the first noble metal oxide and the second noble metal oxide can be formed, respectively.

[0105] The above electroplating process can be performed by a method known in the art.

[0106] According to one embodiment, the electroplating process can be performed under a current within a predetermined range for a time within a predetermined range.

[0107] For example, the lower limit of the current is 0.05 mA / cm 2 , 0.1 mA / cm 2 , 0.15 mA / cm 2 or 0.2 mA / cm 2It can be of the order of 2.0 mA / cm, and its upper limit is 2.0 mA / cm 2 , 1.5 mA / cm 2 , 1.0 mA / cm 2 , 0.5 mA / cm 2 , 0.4 mA / cm 2 , 0.3 mA / cm 2 or 0.2 mA / cm 2 It could be the extent of it.

[0108] In addition, the lower limit of the above time may be about 10 minutes, 20 minutes, 30 minutes, 40 minutes, 50 minutes, 60 minutes, 70 minutes, 80 minutes, 90 minutes, 100 minutes, 110 minutes, 120 minutes, 130 minutes, 140 minutes, 150 minutes, 160 minutes, 170 minutes, 180 minutes, 190 minutes, 200 minutes, 210 minutes, 220 minutes, 230 minutes, 240 minutes, 250 minutes, 260 minutes, 270 minutes, and the upper limit may be about 300 minutes, 290 minutes, 280 minutes, 270 minutes, 260 minutes, 250 minutes, 240 minutes, 230 minutes, 220 minutes, 210 minutes, 200 minutes, 190 minutes. It can be 180 minutes, 170 minutes, 160 minutes, 150 minutes, 140 minutes, 130 minutes, 120 minutes, 110 minutes, 100 minutes, 90 minutes, 80 minutes, 70 minutes, 60 minutes, 50 minutes, 40 minutes, 30 minutes, or 20 minutes.

[0109] The current and time of the electroplating process may each have a range that is 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.

[0110] Depending on the time of the electroplating process, the amount of the first noble metal oxide and the second noble metal oxide formed may vary. For example, the longer the electroplating process time, the greater the amount of the first and second noble metal oxides formed, and the shorter the electroplating process time, the less the amount of the first and second noble metal oxides formed. Therefore, in order to form the appropriate amount of the noble metal oxide, it is necessary to appropriately adjust the time of the electroplating process within the above range.

[0111] The above electroplating process can be performed under a pH within a predetermined range. For example, the pH can be within the range of 8 to 11. When the pH is within the above range, the precursor of the noble metal oxide can be stably plated and grown. Accordingly, in the steps S1 and S2, after the precursor of the first noble metal oxide and the precursor of the second noble metal oxide are added to partially fill the mold, a base compound can be added before performing the electroplating process so that the pH value is within the above range.

[0112] The above basic compound refers to a chemically basic compound. The above basic compound can function as a pH regulator that adjusts the pH so that the pH value falls within the above range.

[0113] These basic compounds contain hydrogen ions (H + ) or accept hydroxide ions (OH - ) is not limited to the type of substance that can emit it.

[0114] In one embodiment, the base compound may be a carbonate metal salt. For example, the carbonate metal salt may include sodium carbonate (Na2CO3), sodium bicarbonate (NaHCO3), magnesium carbonate (MgCO3), calcium carbonate (CaCO3), potassium carbonate (K2CO3), or a combination thereof.

[0115] By including a heterometal composite manufactured according to the above-described method, the purpose according to the present disclosure can be achieved.

[0116] The method for manufacturing a catalyst for oxygen generation reaction of the above-mentioned electrolysis cell may further include, before the step S1, a step (S0) of depositing an electrode including gold (Au), copper (Cu), sodium (Na), aluminum (Al), silver (Au) or a combination thereof on one side of the mold.

[0117] By depositing the above electrodes on one side of the mold, current flows through the deposition surface, and the first noble metal oxide and the second noble metal oxide can be deposited alternately from the location where the electrodes are deposited.

[0118] In addition, the method for manufacturing a catalyst for oxygen generation reaction of the electrolysis cell may further include a step (S1') of removing unreacted substances of the precursor of the first noble metal oxide after the step S1; and a step (S2') of removing unreacted substances of the precursor of the second noble metal oxide after the step S2.

[0119] The above unreacted material refers to a material that forms a first noble metal oxide and a second noble metal oxide, respectively, after the precursor of the first noble metal oxide and the precursor of the second noble metal oxide perform an electroplating process, but at this time, the first noble metal oxide and the second noble metal oxide are not formed and remain as the first noble metal oxide precursor and the second noble metal oxide precursor.

[0120] That is, in the above steps S1' and S2', the unreacted material may be a precursor of the first noble metal oxide and a precursor of the second noble metal oxide, respectively, and the removal of the unreacted material may be performed by a known method. For example, the unreacted material may be removed by a washing method using distilled water.

[0121] In addition, the method for manufacturing a catalyst for an oxygen generation reaction of the electrolysis cell may further include a step (S3) of removing the mold after repeating the steps S1 and S2 n times (n is a natural number greater than or equal to 1); and a step (S4) of performing a heat treatment process to form a heterogeneous precious metal complex including a first precious metal oxide and a second precious metal oxide different from the first precious metal oxide.

[0122] In the above step S3, a known method can be used to remove the mold. In one embodiment, step S3 can use an alkaline solution.

[0123] If an electrode is deposited on one side of the mold according to the above step S0, the step S3 may further include a step (S3-1) of removing the electrode present on one side of the mold.

[0124] In the above step S3-1, the method for removing the electrode can utilize a known method. In one embodiment, step S3-1 can utilize an acid solution.

[0125] The above steps S3 and S3-1 may be performed simultaneously, or the S3 step may be performed first and then the S3-1 step may be performed, or the S3-1 step may be performed first and then the S3 step may be performed.

[0126] In the above step S4, a heterogeneous precious metal complex can be formed through a heat treatment process.

[0127] In the above step S4, the heat treatment process can be performed for a predetermined time at a temperature within a predetermined range.

[0128] For example, the lower limit of the temperature of the heat treatment process may be about 350°C, 360°C, 370°C, 380°C, 390°C, 400°C, 410°C, 420°C, 430°C, 440°C, or 450°C, and the upper limit may be about 600°C, 590°C, 580°C, 570°C, 560°C, 550°C, 540°C, 530°C, 520°C, 510°C, 500°C, 490°C, 480°C, 470°C, 460°C, or 450°C.

[0129] Additionally, the lower limit of the above time may be about 0.5 hours, 0.6 hours, 0.7 hours, 0.8 hours, 0.9 hours or 1 hour, and the upper limit may be about 4 hours, 3.5 hours, 3 hours, 2.5 hours, 2 hours or 1 hour.

[0130] The temperature and time of the heat treatment process may each have a range that is 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.

[0131] The above heterogeneous precious metal complex refers to a structure comprising different types of precious metals. The heterogeneous precious metal complex may comprise a first precious metal oxide and a second precious metal oxide different from the first precious metal oxide.

[0132] As shown on the far right of Fig. 1, a heterogeneous precious metal complex can be formed in which a first precious metal oxide, a second precious metal oxide, and a first precious metal oxide are alternately arranged from the bottom.

[0133] The above first noble metal oxide is a final product formed from a precursor of the above first noble metal oxide. The above second noble metal oxide is a final product formed from a precursor of the above second noble metal oxide. As described above, "first" and "second" are merely denoted as "first" and "second", respectively, to identify different types of noble metal oxides, and do not indicate a priority among the noble metal oxides.

[0134] The above heterogeneous precious metal complex has a nanowire shape, and the first precious metal oxide and the second precious metal oxide may be arranged alternately in the length direction.

[0135] By manufacturing a heterogeneous precious metal composite comprising different first and second precious metal oxides, the amount of precious metal, particularly iridium (Ir), used can be reduced, thereby improving performance. Furthermore, according to the examples and comparative examples of the present disclosure, it was confirmed that performance is improved when different heterogeneous metals are used compared to when a single metal is used.

[0136]

[0137] 3. Membrane-electrode assembly for electrolysis cell

[0138] 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.

[0139] The membrane-electrode assembly for the above-described electrolysis cell is illustrated in FIG. 5. The membrane-electrode assembly (100) for the electrolysis cell according to FIG. 5 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.

[0140] Hereinafter, the oxygen generation electrode, the hydrogen generation electrode, and the polymer electrolyte membrane will be described in detail.

[0141] The above oxygen evolution electrode refers to an electrode where an oxygen evolution reaction (OER) occurs.

[0142] The above oxygen generation electrode includes a catalyst for the oxygen generation reaction of the water electrolysis cell.

[0143] 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.”

[0144] The membrane-electrode assembly for the above electrolysis cell can have improved performance by including a catalyst for the oxygen evolution reaction of the electrolysis cell including the heterogeneous precious metal complex. The improved performance can be expressed as a current density measured at 1.7 V, as described in the "IV Measurement Method" section of Evaluation Example 1 below.

[0145] The membrane-electrode assembly for the above electrolytic cell can have a current density measured at 1.7 V within a predetermined range.

[0146] For example, the lower limit of the current density is 2.0 A / cm 2 , 2.05 A / cm 2 , 2.1 A / cm 2 , 2.15 A / cm 2 , 2.2 A / cm 2 , 2.25 A / cm 2 , 2.3 A / cm 2 , 2.35 A / cm 2 , 2.4 A / cm 2 , 2.45 A / cm 2 , 2.5 A / cm 2 , 2.55 A / cm 2 , 2.6 A / cm 2 or 2.65 A / cm 2 It can be of the order of 3.0 A / cm, but its upper limit is not limited. 2 , 2.9 A / cm2 , 2.8 A / cm 2 , 2.7 A / cm 2 , 2.6 A / cm 2 , 2.5 A / cm 2 , 2.4 A / cm 2 , 2.3 A / cm 2 , 2.2 A / cm 2 , 2.1 A / cm 2 or 2.05 A / cm 2 It could be the extent of it.

[0147] The current density may be greater than or equal to any one of the lower limits described above; or may be 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.

[0148] The above oxygen generation electrode may include an oxygen generation reaction catalyst within a predetermined range with respect to the total weight of the oxygen generation electrode.

[0149] For example, the lower limit of the content of the catalyst for the oxygen generation reaction may be about 70 wt% or 75 wt%, and the upper limit may be about 90 wt% or 95 wt%.

[0150] 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.

[0151] The above oxygen generation electrode may further include an ion conductor to improve the adhesion of the catalyst and transfer hydrogen ions.

[0152] The above ion conductor may include a cation exchanger to ensure ion conductivity.

[0153] 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.

[0154] The above ion conductor may be a fluorine-based ion conductor, a hydrocarbon-based ion conductor, or a mixture thereof.

[0155] 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.

[0156] 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.

[0157] According to one embodiment, the ion conductor may have hydrogen ion conductivity.

[0158] 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.

[0159] The content of the above ion conductor can be appropriately adjusted as needed. In one example, the lower limit of the content of the above ion conductor relative to 100 parts by weight of the oxygen generation reaction catalyst can be about 5 parts by weight or 10 parts by weight, and the upper limit can be about 30 parts by weight or 25 parts by weight.

[0160] 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.

[0161] 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 to further enhance adhesion to the polymer electrolyte membrane. The content of the non-conductive compound can be appropriately adjusted depending on the intended use.

[0162] 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.

[0163] The above hydrogen generation electrode refers to an electrode where a hydrogen evolution reaction (Hydrogen Evolution Reaction (HER)) occurs.

[0164] 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.

[0165] The above active particles may include a precious metal.

[0166] For example, the precious metal may be a platinum-based precious metal.

[0167] 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).

[0168] 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.

[0169] The above carrier may be a carbon-based carrier.

[0170] 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.

[0171] 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.

[0172] At this time, the electrode substrate can play a role in supporting the electrode and diffusing the fuel and oxidant to the catalyst layer.

[0173] The electrode substrate may include a microporous layer, a porous diffusion layer, or a combination thereof.

[0174] 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.

[0175] 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).

[0176] The above microporous layer and the above porous diffusion layer may include known materials in addition to those exemplified above.

[0177] 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.

[0178] 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.

[0179] 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.

[0180] 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.

[0181] The above porous support may be a fluorine-based support or a nano web support.

[0182] 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.

[0183] 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.

[0184] The above ion conductor is as described above.

[0185] 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.

[0186]

[0187] 4. Susan Hae-cell

[0188] In one embodiment, the electrolysis cell comprises a membrane-electrode assembly for the electrolysis cell.

[0189] 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.

[0190] Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement them. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein.

[0191] Example 1-1

[0192] (a) An electrode containing Ag was deposited on one surface of an AAO film including a substrate and a plurality of pores penetrating the substrate in the thickness direction, and the AAO film was connected to an electroplating device.

[0193] At this time, the diameter of the pore was 50 nm, and the length of the pore was about 900 nm.

[0194] (n) Approximately 10 ml of a mixture of 70 mg and 200 mg of IrCl4 from Sigma-Aldrich, a precursor of the first noble metal oxide, and oxalic acid from Sigma-Aldrich, a weak reducing agent, in 50 ml of water (H2O) was added to fill part of the AAO film.

[0195] (ㄷ) After adjusting the pH value to 10 by adding 0.5 ml of 1M Sigma-Aldrich K2CO3 as a base compound, 0.2 mA / cm 2 The first noble metal oxide was formed by performing an electroplating process for 1 hour under current.

[0196] (L) The unreacted precursor of the first noble metal oxide was removed from the AAO film by washing it with distilled water.

[0197] (ㅁ) About 10 ml of a mixture of 70 mg and 200 mg of RuCl4 from Sigma-Aldrich, a precursor of the second noble metal oxide, and oxalic acid, a weak reducing agent, in 50 ml of water (H2O) was added to fill a portion of the AAO film on top of the first noble metal oxide.

[0198] (ㅂ) After adjusting the pH value to 10 by adding 0.5 ml of 1M Sigma-Aldrich K2CO3 as a base compound, 0.2 mA / cm 2 The second noble metal oxide was formed by performing an electroplating process for 1 hour under current.

[0199] (ㅅ) The unreacted precursor of the second noble metal oxide was removed from the AAO film by washing it with distilled water.

[0200] After repeating the above (n) to (s) n times, the mold and the deposited Ag were removed with NaOH and HNO3, respectively, and then a heat treatment process was performed at 450°C for 1 hour to form a heterogeneous precious metal complex including a first precious metal oxide and a second precious metal oxide.

[0201] As shown in the optical microscope photograph of Fig. 2, the heterogeneous precious metal complex was in the form of a nanowire in which a first precious metal oxide of IrO2 and a second precious metal oxide of RuO2 alternately existed, and as a result of photographing and measuring the heterogeneous precious metal complex using a scanning electron microscope (SEM), the length of the nanowire was approximately 500 nm, and the weight ratio of the first precious metal oxide (IrO2) and the second precious metal oxide (RuO2) in the heterogeneous precious metal complex was 60:40.

[0202]

[0203] Example 1-2

[0204] A heterogeneous precious metal complex was formed in the same manner as in Example 1-1, except that the electroplating process of (d) was performed for 2 hours and the electroplating process of (b) was performed for 20 minutes.

[0205] At this time, the heterogeneous precious metal complex was in the form of a nanowire in which a first precious metal oxide of IrO2 and a second precious metal oxide of RuO2 alternately existed, and as a result of photographing and measuring the heterogeneous precious metal complex using a scanning electron microscope (SEM), the length of the nanowire was approximately 500 nm, and the weight ratio of the first precious metal oxide (IrO2) and the second precious metal oxide (RuO2) in the heterogeneous precious metal complex was 80:20.

[0206]

[0207] Example 1-3

[0208] A heterogeneous precious metal complex was formed in the same manner as in Example 1-1, except that the electroplating process of (d) was performed for 20 minutes and the electroplating process of (b) was performed for 2 hours.

[0209] At this time, the heterogeneous precious metal complex was in the form of a nanowire in which a first precious metal oxide of IrO2 and a second precious metal oxide of RuO2 alternately existed, and as a result of photographing and measuring the heterogeneous precious metal complex using a scanning electron microscope (SEM), the length of the nanowire was approximately 500 nm, and the weight ratio of the first precious metal oxide (IrO2) and the second precious metal oxide (RuO2) in the heterogeneous precious metal complex was 20:80.

[0210]

[0211] Example 1-4

[0212] A heterogeneous noble metal complex was formed in the same manner as in Example 1-1, except that the amounts of the first noble metal oxide precursor, the second noble metal oxide precursor, and the weak reducing agent of (n) and (m) above were each used in amounts only 2 / 3 of those in Example 1-1.

[0213] At this time, the heterogeneous precious metal complex was in the form of a nanowire in which a first precious metal oxide of IrO2 and a second precious metal oxide of RuO2 alternately existed, and as a result of photographing and measuring the heterogeneous precious metal complex using a scanning electron microscope (SEM), the length of the nanowire was approximately 300 nm, and the weight ratio of the first precious metal oxide (IrO2) and the second precious metal oxide (RuO2) in the heterogeneous precious metal complex was 60:40.

[0214]

[0215] Example 1-5

[0216] A heterogeneous noble metal complex was formed in the same manner as in Example 1-1, except that the amount of the first noble metal oxide precursor and the second noble metal oxide precursor and the weak reducing agent of (n) and (m) above were each used in an amount 1.5 times that of Example 1-1.

[0217] At this time, the heterogeneous precious metal complex was in the form of a nanowire in which a first precious metal oxide of IrO2 and a second precious metal oxide of RuO2 alternately existed, and as a result of photographing and measuring the heterogeneous precious metal complex using a scanning electron microscope (SEM), the length of the nanowire was approximately 800 nm, and the weight ratio of the first precious metal oxide (IrO2) and the second precious metal oxide (RuO2) in the heterogeneous precious metal complex was 60:40.

[0218]

[0219] Example 2-1

[0220] A dual noble metal complex was formed in the same manner as in Example 1-1, except that SnCl4 from Sigma-aldrich was used as a precursor of the second noble metal oxide.

[0221] As shown in the optical microscope photograph of Fig. 3, the heterogeneous precious metal complex was in the form of a nanowire in which a first precious metal oxide of IrO2 and a second precious metal oxide of SnO2 alternately existed, and as a result of photographing and measuring the heterogeneous precious metal complex using a scanning electron microscope (SEM), the length of the nanowire was approximately 500 nm, and the weight ratio of the first precious metal oxide (IrO2) and the second precious metal oxide (SnO2) in the heterogeneous precious metal complex was 70:30.

[0222]

[0223] Example 2-2

[0224] A heterogeneous precious metal complex was formed in the same manner as in Example 2-1, except that the electroplating process of (d) was performed for 30 minutes and the electroplating process of (b) was performed for 2.5 hours.

[0225] The above heterogeneous precious metal complex was in the form of a nanowire in which a first noble metal oxide of IrO2 and a second noble metal oxide of SnO2 alternately existed, and as a result of photographing and measuring the heterogeneous precious metal complex using a scanning electron microscope (SEM), the length of the nanowire was approximately 500 nm, and the weight ratio of the first noble metal oxide (IrO2) and the second noble metal oxide (SnO2) in the heterogeneous precious metal complex was 30:70.

[0226]

[0227] Example 2-3

[0228] A heterogeneous precious metal complex was formed in the same manner as in Example 2-1, except that the electroplating process of (d) was performed for 45 minutes and the electroplating process of (b) was performed for 1.5 hours.

[0229] The above heterogeneous precious metal complex was in the form of a nanowire in which a first precious metal oxide of IrO2 and a second precious metal oxide of SnO2 alternately existed, and when the heterogeneous precious metal complex was photographed and measured using a scanning electron microscope (SEM), the length of the nanowire was approximately 500 nm, and the weight ratio of the first precious metal oxide (IrO2) and the second precious metal oxide (SnO2) in the heterogeneous precious metal complex was 50:50.

[0230]

[0231] Example 2-4

[0232] A heterogeneous noble metal complex was formed in the same manner as in Example 2-1, except that the amounts of the first noble metal oxide precursor, the second noble metal oxide precursor, and the weak reducing agent of (n) and (m) above were used only 2 / 3 of the amounts of Example 2-1.

[0233] The above heterogeneous precious metal complex was in the form of a nanowire in which a first noble metal oxide of IrO2 and a second noble metal oxide of SnO2 alternately existed, and as a result of photographing and measuring the heterogeneous precious metal complex using a scanning electron microscope (SEM), the length of the nanowire was approximately 300 nm, and the weight ratio of the first noble metal oxide (IrO2) and the second noble metal oxide (SnO2) in the heterogeneous precious metal complex was 70:30.

[0234]

[0235] Example 2-5

[0236] A heterogeneous noble metal complex was formed in the same manner as in Example 2-1, except that the amounts of the first noble metal oxide precursor, the second noble metal oxide precursor, and the weak reducing agent of (n) and (m) above were each used in amounts 1.5 times greater than those in Example 2-1.

[0237] The above heterogeneous precious metal complex was in the form of a nanowire in which IrO2 metal oxide and SnO2 metal oxide alternately existed, and as a result of photographing and measuring the heterogeneous precious metal complex using a scanning electron microscope (SEM), the length of the nanowire was approximately 800 nm, and the weight ratio of the first noble metal oxide (IrO2) and the second noble metal oxide (SnO2) in the heterogeneous precious metal complex was 70:30.

[0238]

[0239] Example 3

[0240] A heterogeneous noble metal complex was formed in the same manner as in Example 1-1, except that NbCl4 from Sigma-aldrich was used as a precursor of the second noble metal oxide.

[0241] The above heterogeneous precious metal complex was in the form of a nanowire in which a first precious metal oxide of IrO2 and a second precious metal oxide of NbO2 alternately existed, and as a result of photographing and measuring the heterogeneous precious metal complex using a scanning electron microscope (SEM), the length of the nanowire was approximately 500 nm, and the weight ratio of the first precious metal oxide (IrO2) and the second precious metal oxide (NbO2) in the heterogeneous precious metal complex was 60:40.

[0242]

[0243] Example 4

[0244] A heterogeneous noble metal complex was formed in the same manner as in Example 1-1, except that WCl4 from Sigma-aldrich was used as a precursor of the second noble metal oxide.

[0245] The above heterogeneous noble metal complex was in the form of a nanowire in which a first noble metal oxide of IrO2 and a second noble metal oxide of WO2 alternately existed. As a result of photographing and measuring the heterogeneous noble metal complex using a scanning electron microscope (SEM), the length of the nanowire was approximately 500 nm, and the weight ratio of the first noble metal oxide (IrO2) and the second noble metal oxide (WO2) in the heterogeneous noble metal complex was 70:30.

[0246]

[0247] Comparative Example 1

[0248] A nanowire-shaped noble metal catalyst containing only IrO2 metal oxide was manufactured in the same manner as in Example 1-1, except that only the precursor of IrO2 metal oxide was added to fill the AAO film without adding the precursor of RuO2 metal oxide.

[0249] The SEM image before removing the mold to form the above precious metal catalyst is as shown in Fig. 4.

[0250] The length of the nanowire was measured by photographing the above noble metal catalyst using a scanning electron microscope (SEM) and was found to be approximately 500 nm.

[0251]

[0252] Evaluation Example 1. IV Characteristics

[0253] 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 evolution reaction catalyst of the electrolysis cell manufactured in Examples 1-1 to 1-5, 2-1 to 2-5, 3, 4 and Comparative Example 1, 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.

[0254] 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 a cell temperature of 80°C, a water temperature of 80°C, and a flow rate of 5 ml / min using a protocol for measuring the voltage and resistance, and the measurement was stopped at 2 V.

[0255]

[0256] The results at this time are shown in Table 1. And, the results for Example 1-1, Example 2-1, and Comparative Example 1 are as shown in Fig. 6.

[0257] Performance (A / cm) 2 @1.7V) Example 1-12.50 Example 1-22.36 Example 1-32.02 Example 1-42.33 Example 1-52.11 Example 2-12.68 Example 2-22.08 Example 2-32.31 Example 2-42.36 Example 2-52.24 Example 32.29 Example 42.22 Comparative Example 11.94

[0258]

[0259] result

[0260] As can be seen in Fig. 6, the membrane-electrode assembly including the oxygen evolution reaction catalyst manufactured according to Examples 1-1, 2-1, 3 and 4 in which different noble metal oxides are alternately arranged to form nanowires exhibits a higher current density at the same voltage compared to the membrane-electrode assembly including the oxygen evolution reaction catalyst manufactured according to Comparative Example 1 in which nanowires are formed of a single noble metal oxide, confirming improved performance.

[0261] In addition, as can be seen in Table 1, it can be confirmed that the membrane-electrode assembly including the oxygen evolution reaction catalyst manufactured according to Examples 1-1 to 1-5, 2-1 to 2-5, 3 and 4, in which different noble metal oxides are alternately arranged to form nanowires even when the length of the nanowires and the weight ratio of the first noble metal oxide and the second noble metal oxide are different, has superior performance compared to the membrane-electrode assembly including the oxygen evolution reaction catalyst manufactured according to Comparative Example 1, in which nanowires are formed of a single noble metal oxide.

[0262]

[0263] Although the preferred embodiments have been described in detail above, the scope of the rights 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 rights.

[0264] [Explanation of symbols]

[0265] 100: Membrane-electrode assembly for electrolysis cell

[0266] 10: Oxygen generation electrode

[0267] 20: Hydrogen generation electrode

[0268] 30: Polymer electrolyte membrane

Claims

1. A hetero-precious metal complex comprising a first precious metal oxide and a second precious metal oxide different from the first precious metal oxide, The above heterogeneous precious metal complex has a nanowire shape. Catalyst for oxygen evolution reaction in a water electrolysis cell.

2. In paragraph 1, The above first noble 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.

3. In paragraph 1, The above second precious metal oxide is MO x (The above M includes Ru, Pt, Sn, Se, Sb, Ta, Te, Nb, W, Zn, Au, or a combination thereof, and the above x is an integer from 1 to 3) A catalyst for oxygen evolution reaction in a water electrolysis cell.

4. In paragraph 1, A catalyst for oxygen evolution reaction in a water electrolysis cell, wherein the length of the above nanowires is in the range of 100 nm to 1,000 nm.

5. In paragraph 1, The above first precious metal oxide is included in a range of 10 wt% to 90 wt% based on the total weight of the heterogeneous precious metal complex. Catalyst for oxygen evolution reaction in a water electrolysis cell.

6. In paragraph 1, In the above heterogeneous precious metal complex, The weight ratio of the first noble metal oxide and the second noble metal oxide is within the range of 1:9 to 9:

1. Catalyst for oxygen evolution reaction in a water electrolysis cell.

7. In paragraph 1, The above heterogeneous precious metal complex is, A first noble metal oxide layer comprising the first noble metal oxide, and a second noble metal oxide layer comprising the second noble metal oxide, Catalyst for oxygen evolution reaction in a water electrolysis cell.

8. In paragraph 7, The above heterogeneous precious metal complex is, The first noble metal oxide layer and the second noble metal oxide layer are alternately arranged in the longitudinal direction of the nanowire. Catalyst for oxygen evolution reaction in a water electrolysis cell.

9. In paragraph 8, The first noble metal oxide layer and the second noble metal oxide layer are each independently a minimum repeating unit, The above hetero-precious metal complex has repeating units of two or more of the first precious metal oxide layers and has repeating units of one or more of the second precious metal oxide layers. Catalyst for oxygen evolution reaction in a water electrolysis cell.

10. In paragraph 9, The above heterogeneous precious metal complex is, Containing 2 to 10 layers of the first precious metal oxide, Containing 1 to 9 of the second precious metal oxide layers, Catalyst for oxygen evolution reaction in a water electrolysis cell.

11. In paragraph 9, The length of the first noble metal oxide layer is within a range of 10 nm to less than 1,000 nm, The length of the second noble metal oxide layer is within a range of 10 nm to less than 1,000 nm. Catalyst for oxygen evolution reaction in a water electrolysis cell.

12. In paragraph 9, The ratio of the length of the first noble metal oxide layer to the length of the second noble metal oxide layer is within the range of 1:0.1 to 1:

10. Catalyst for oxygen evolution reaction in a water electrolysis cell.

13. Step (S1) of injecting a precursor of the first precious metal oxide to fill part of the mold and performing an electroplating process; and A step (S2) of introducing a precursor of the first noble metal oxide and a precursor of a second noble metal oxide different from each other to fill a portion of the mold and performing an electroplating process; Including, Repeating the above steps S1, S2, or both of these steps n times (where n is a natural number greater than or equal to 1), A method for producing a catalyst for oxygen generation reaction in a water electrolysis cell.

14. In paragraph 13, The above mold is an AAO membrane (anodic aluminum oxide membrane) including a substrate and a plurality of pores penetrating the substrate in the thickness direction, The precursor of the first noble metal oxide and the precursor of the second noble metal oxide are alternately filled in the pores. A method for producing a catalyst for oxygen generation reaction in a water electrolysis cell.

15. In paragraph 13, The above electroplating process is 0.05 mA / cm 2 Within 2.0 mA / cm 2 , which is performed for 10 to 300 minutes under current within the range of A method for producing a catalyst for oxygen generation reaction in a water electrolysis cell.

16. In paragraph 13, After repeating the above steps S1 and S2 n times (n is a natural number greater than or equal to 1), Step (S3) of removing the above mold; and A step (S4) further comprising performing a heat treatment process to form a heterogeneous precious metal complex including a first precious metal oxide and a second precious metal oxide different from the first precious metal oxide. A method for producing a catalyst for oxygen generation reaction in a water electrolysis cell.

17. In paragraph 16, The above S3 step uses an alkaline solution, A method for producing a catalyst for oxygen generation reaction in a water electrolysis cell.

18. Polymer electrolyte membrane; An oxygen generation electrode positioned on one side of the polymer electrolyte membrane and including a catalyst for oxygen generation reaction for water electrolysis 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.

19. In Article 18, The current density measured at 1.7 V under the conditions of cell temperature 80℃, water temperature 80℃, and flow rate 5ml / min was 2.0 A / cm 2 Strange person, Membrane-electrode assembly for a water electrolysis cell.

20. A water electrolysis cell comprising a membrane electrode assembly according to claim 18.

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