US20200208277A1 - Apparatus for electrochemically generating oxygen - Google Patents

Apparatus for electrochemically generating oxygen Download PDF

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US20200208277A1
US20200208277A1 US16/634,104 US201816634104A US2020208277A1 US 20200208277 A1 US20200208277 A1 US 20200208277A1 US 201816634104 A US201816634104 A US 201816634104A US 2020208277 A1 US2020208277 A1 US 2020208277A1
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oxygen
cathode
water
anode
outer frame
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Yong Tae Kim
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Faraday O2 Inc
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Faraday O2 Inc
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Priority claimed from PCT/KR2018/008438 external-priority patent/WO2019022515A1/ko
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    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B1/00—Electrolytic production of inorganic compounds or non-metals
    • C25B1/01—Products
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    • C25B1/04—Hydrogen or oxygen by electrolysis of water
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    • C25B11/051—Electrodes formed of electrocatalysts on a substrate or carrier
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    • C25B11/073—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material
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    • C25B11/073—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material
    • C25B11/075—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of a single catalytic element or catalytic compound
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    • C25B11/073—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material
    • C25B11/075—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of a single catalytic element or catalytic compound
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    • C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
    • C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
    • C25B11/051—Electrodes formed of electrocatalysts on a substrate or carrier
    • C25B11/073—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material
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    • C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
    • C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
    • C25B11/051—Electrodes formed of electrocatalysts on a substrate or carrier
    • C25B11/073—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material
    • C25B11/091—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of at least one catalytic element and at least one catalytic compound; consisting of two or more catalytic elements or catalytic compounds
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B13/00—Diaphragms; Spacing elements
    • C25B13/04—Diaphragms; Spacing elements characterised by the material
    • C25B13/08—Diaphragms; Spacing elements characterised by the material based on organic materials
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B9/00—Cells or assemblies of cells; Constructional parts of cells; Assemblies of constructional parts, e.g. electrode-diaphragm assemblies; Process-related cell features
    • C25B9/17—Cells comprising dimensionally-stable non-movable electrodes; Assemblies of constructional parts thereof
    • C25B9/19—Cells comprising dimensionally-stable non-movable electrodes; Assemblies of constructional parts thereof with diaphragms
    • C25B9/23—Cells comprising dimensionally-stable non-movable electrodes; Assemblies of constructional parts thereof with diaphragms comprising ion-exchange membranes in or on which electrode material is embedded
    • C—CHEMISTRY; METALLURGY
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    • C25B9/00—Cells or assemblies of cells; Constructional parts of cells; Assemblies of constructional parts, e.g. electrode-diaphragm assemblies; Process-related cell features
    • C25B9/70—Assemblies comprising two or more cells
    • C25B9/73—Assemblies comprising two or more cells of the filter-press type
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/36—Hydrogen production from non-carbon containing sources, e.g. by water electrolysis

Definitions

  • the present invention relates to an electrochemical oxygen generator, and more particularly, to an electrochemical oxygen generator applicable to various fields such as in portable, domestic, medical, vehicular, or industrial oxygen generating devices, oxygen pumps, oxygen compressors, or oxygen concentrators.
  • oxygen is an essential element for the survival of humankind, and in various fields, technology for generating high purity oxygen as needed is being considered to be very important.
  • oxygen generators are applied to various fields such as in portable, domestic, medical, vehicular, or industrial oxygen generating devices, oxygen pumps, oxygen compressors, or oxygen concentrators.
  • Such an oxygen generator uses the conventional pressure swing adsorption (PSA) method, membrane separation method, or oxygen generating technology using an oxygen tank.
  • PSA pressure swing adsorption
  • the conventional oxygen generating technology such as the PSA method or the membrane separation method is highly expensive due to a large size of a system due to a complicated oxygen generating process and use of a large amount of an adsorbent or the like.
  • the conventional oxygen generating technology such as the PSA method or the membrane separation method is highly expensive due to a large size of a system due to a complicated oxygen generating process and use of a large amount of an adsorbent or the like.
  • noise and vibration inevitably occur.
  • the oxygen generator using the oxygen tank has advantages in that it is possible to lower the price of the oxygen generator, miniaturize the oxygen generator, and implement noise-free and vibration-free oxygen generation but has a problem in that the oxygen tank should be periodically filled with oxygen from a specialized gas company in accordance with the use of the oxygen generator. Furthermore, the oxygen generator has a problem in that it is very inconvenient to use the oxygen generator due to the usage time of the oxygen generator being limited to the size of the oxygen tank.
  • the present invention is directed to providing an electrochemical oxygen generator capable of generating oxygen without noise and vibration using an electrochemical method and being manufactured as a miniaturized device.
  • Oxygen (O 2 ) may be generated at the anode using the oxygen evolution reaction (OER), and water (H 2 O) may be generated at the cathode using the oxygen reduction reaction (ORR).
  • OER oxygen evolution reaction
  • ORR oxygen reduction reaction
  • an oxygen generator includes a membrane-electrode assembly including an anode connected to a first electrode of a power supply, a cathode connected to a second electrode of the power supply, and an electrolyte membrane provided between the anode and the cathode, a water supply source configured to supply water to the anode, and an air supply unit configured to supply oxygen to the cathode, wherein oxygen (O 2 ) is generated at the anode using an OER, and water (H 2 O) is generated at the cathode using an ORR.
  • a membrane-electrode assembly including an anode connected to a first electrode of a power supply, a cathode connected to a second electrode of the power supply, and an electrolyte membrane provided between the anode and the cathode, a water supply source configured to supply water to the anode, and an air supply unit configured to supply oxygen to the cathode, wherein oxygen (O 2 ) is generated at the anode using an OER,
  • the oxygen generator may further include a water collection line configured to collect water (H 2 O) generated at the cathode in the water supply source.
  • the oxygen generator may further include a first outer frame portion positioned outside the anode and a second outer frame portion positioned outside the cathode, wherein the first outer frame portion includes a first outer frame, a water inlet positioned at one side of the first outer frame, and an oxygen outlet positioned at the other side of the first outer frame, and the second outer frame portion includes a second outer frame, an oxygen inlet positioned at one side of the second outer frame, and a water outlet positioned at the other side of the second outer frame.
  • Water (H 2 O) supplied from the water supply source may be supplied to the anode through the water inlet, hydrogen ions (H + ), oxygen (O 2 ), and electrons may be generated by electrolyzing water (H 2 O) and the generated oxygen (O 2 ) may be discharged through the oxygen outlet at the anode, and oxygen (O 2 ) in air supplied from the oxygen inlet may react with hydrogen ions (H + ) being moved by passing through the electrolyte membrane to generate water (H 2 O) and the generated water (H 2 O) may be discharged through the water outlet at the cathode.
  • the anode may include a first support and a first catalyst layer positioned at one side of the first support, the first support may include carbon black, Ketjen black, acetylene black, an activated carbon powder, a carbon molecular sieve, carbon nanotubes, activated carbon having fine pores, mesoporous carbon, a conductive polymer, or a mixture thereof, and the first catalyst layer may include at least one catalyst for an OER selected from the group consisting of metals including platinum (Pt), iridium (Ir), ruthenium (Ru), nickel (Ni), manganese (Mn), cobalt (Co), iron (Fe), titanium (Ti), rhenium (Re), niobium (Nb), vanadium (V), sulfur (S), and molybdenum (Mo) and the metals combined with an oxide, a nitride, a carbide, a phosphide, and a sulfide.
  • the first support may include carbon black, Ke
  • the cathode may include a second support and a second catalyst layer positioned at one side of the second support, the second support may include at least one material selected from the group consisting of carbon or transition metals combined with an oxide, a nitride, a carbide, a phosphide, and a sulfide, and the second catalyst layer may include at least one catalyst for an ORR selected from the group consisting of platinum (Pt), palladium (Pd), iridium (Ir), gold (Au), silver (Ag), and alloys thereof.
  • the cathode may include a second support and a second catalyst layer positioned at one side of the second support, the second support may include at least one material selected from the group consisting of carbon or transition metals combined with an oxide, a nitride, a carbide, a phosphide, and a sulfide, and the second catalyst layer may include an Fe—N—C catalyst.
  • the Fe—N—C catalyst may inhibit a hydrogen evolution reaction and promote an ORR.
  • an oxygen generator for generating oxygen (O 2 ) using a simple configuration including a membrane-electrode assembly, a power supply capable of applying a certain amount of power, and a water supply source capable of supplying water to an anode of the membrane-electrode assembly.
  • FIG. 1 is a schematic diagram for describing a principle of an oxygen generator according to the present invention.
  • FIG. 2 is a schematic exploded perspective view illustrating an application example of an oxygen generator according to the present invention.
  • FIG. 3 is a partially assembled perspective view illustrating the application example of the oxygen generator according to the present invention.
  • FIG. 4 is a schematic view illustrating an assembled state of the application example of the oxygen generator according to the present invention excluding a gasket.
  • FIG. 5 is a graph showing a change in oxygen generation current density according to a voltage of Experimental Example 1.
  • FIG. 6 is a graph showing a change in oxygen generation current density according to a voltage of Experimental Example 2.
  • FIG. 7 is a graph showing a change in oxygen generation current density according to a voltage of Experimental Example 3.
  • FIG. 8 is a graph showing a change in oxygen generation current density according to a voltage of Experimental Example 4.
  • FIG. 9 is a graph showing a change in oxygen generation current density according to a flow rate of air of Experimental Example 5.
  • FIG. 10 is a graph showing a change in oxygen generation current density according to a voltage of Experimental Example 6.
  • FIG. 11 is a graph showing a change in oxygen generation current density according to a voltage of Experimental Example 7.
  • FIG. 12 is a graph showing a change in oxygen generation current density according to a voltage of Experimental Example 8.
  • spatially relative terms such as “below,” “beneath,” “lower,” “above,” “upper” and the like, may be used to easily describe relationships between one component and another component as shown in the drawings. It will be understood that the spatially relative terms are intended to encompass different orientations of components in use or in operation, in addition to the orientation depicted in the drawings. For example, if a component shown in the drawing is turned over, a component described as “below,” “beneath,” or “under” another component would then be oriented “above” another component. Thus, the exemplary term “below” can encompass both an orientation of above and below. Since a component may be oriented in another direction, the spatially relative terms may be interpreted in accordance with the orientation of the component.
  • an oxygen evolution reaction occurs at an anode
  • a hydrogen evolution reaction occurs at a cathode
  • an oxygen reduction reaction occurs at an anode
  • a hydrogen oxidation reaction occurs at a cathode
  • the following reactions occur in an anode and a cathode.
  • oxygen (O 2 ) is generated at the anode using an OER that is a water electrolysis reaction
  • water (H 2 O) is generated at the cathode using an ORR that is a fuel cell reaction.
  • FIG. 1 is a schematic diagram for describing a principle of an oxygen generator according to the present invention.
  • an oxygen generator 10 includes a membrane-electrode assembly 60 including an anode 30 connected to a first electrode of a power supply 20 , a cathode 40 connected to a second electrode of the power supply, and an electrolyte membrane 50 provided between the anode and the cathode.
  • the first electrode may be a positive electrode
  • the second electrode may be a negative electrode.
  • the oxygen generator 10 includes a water supply source 70 for supplying water to the anode 30 and an air supply unit 80 for supplying oxygen to the cathode 40 .
  • the air supply unit 80 may be for supplying oxygen to the cathode 40 and may supply general air to the cathode to supply oxygen to the cathode 40 .
  • the supply of oxygen by the air supply unit 80 may be understood to mean that air is supplied to the cathode 40 .
  • the air supply unit 80 may use a known fan, but a type of the air supply unit 80 is not limited thereto.
  • air may be forcibly supplied to the cathode 40 by operating the fan, thereby supplying oxygen to the cathode 40 .
  • the supply of oxygen through such a forcible method may be expressed as an air flow rate, which will be described below.
  • hydrogen ions (H + ) generated at the anode move to the cathode by passing through the electrolyte membrane 50 .
  • oxygen (O 2 ) in air supplied from the air supply unit 80 reacts with hydrogen ions (H + ) being moved by passing through the electrolyte membrane 50 to generate water (H 2 O).
  • oxygen (O 2 ) is generated using an OER
  • water (H 2 O) is generated using an ORR
  • the oxygen generator 10 may further include a water collection line 90 for collecting water (H 2 O) generated at the cathode 40 in the water supply source 70 .
  • a water collection line 90 for collecting water (H 2 O) generated at the cathode 40 in the water supply source 70 .
  • water (H 2 O) generated at the cathode 40 is illustrated as being collected in the water supply source 70 , but water (H 2 O) generated at the cathode 40 may be discharged through any discharge line.
  • water (H 2 O) generated at the cathode 40 may be collected in the water supply source 70 .
  • the oxygen generator for generating oxygen (O 2 ) at the anode.
  • oxygen (O 2 ) generated at the anode may be applied to various fields such as in portable, domestic, medical, vehicular, or industrial oxygen generating devices, oxygen pumps, oxygen compressors, or oxygen concentrators.
  • the oxygen generator for generating oxygen using a simple configuration including the membrane-electrode assembly 60 including the anode 30 , the cathode 40 , and the electrolyte membrane 50 provided between the anode and the cathode, the power supply 20 capable of applying a certain amount of power to the anode and the cathode, the water supply source 70 capable of supplying water to the anode, and the air supply unit 80 for supplying oxygen to the cathode 40 .
  • an oxygen generator using an oxygen tank has a problem in that the oxygen tank should be periodically filled with oxygen from a specialized gas company in accordance with the use of the oxygen generator.
  • the oxygen generator for generating oxygen (O 2 ) using a simple configuration including the membrane-electrode assembly 60 , the power supply 20 capable of applying a certain amount of power, the water supply source 70 capable of supplying water to the anode of the membrane-electrode assembly, and the air supply unit 80 for supplying oxygen to the cathode of the membrane-electrode assembly.
  • an electrochemical oxygen generator can be provided such that oxygen is generated without noise and vibration using an electrochemical method and the electrochemical oxygen generator is also miniaturized due to a simple device configuration.
  • FIG. 2 is a schematic exploded perspective view illustrating an application example of an oxygen generator according to the present invention.
  • FIG. 3 is a partially assembled perspective view illustrating the application example of the oxygen generator according to the present invention.
  • FIG. 4 is a schematic view illustrating an assembled state of the application example of the oxygen generator according to the present invention except for a gasket.
  • an application example 100 of an oxygen generator according to the present invention includes a membrane-electrode assembly 60 including an anode 30 connected to a first electrode of a power supply 20 , a cathode 40 connected to a second electrode of the power supply, and an electrolyte membrane 50 provided between the anode and the cathode.
  • the first electrode may be a positive electrode
  • the second electrode may be a negative electrode.
  • the application example 100 of the oxygen generator according to the present invention includes a water supply source 70 for supplying water to the anode 30 and an air supply unit 70 for supplying oxygen to the cathode 40 .
  • the air supply unit 70 may be for supplying oxygen to the cathode 40
  • the air supply unit 80 may supply general air to the cathode to supply oxygen to the cathode 40 .
  • the supply of oxygen by the air supply unit 80 may be understood to mean that air is supplied to the cathode 40 .
  • the air supply unit 80 may use a known fan, but a type of the air supply unit 80 is not limited thereto.
  • air may be forcibly supplied to the cathode 40 by operating the fan, thereby supplying oxygen to the cathode 40 .
  • the supply of oxygen through such a forcible method may be expressed as an air flow rate, which will be described below.
  • the application example 100 of the oxygen generator according to the present invention may further include a water collection line 90 for collecting water (H 2 O) generated at the cathode 40 in the water supply source 70 .
  • the application example 100 of the oxygen generator device according to the present invention includes a first outer frame portion 110 positioned outside the anode 30 and a second outer frame portion 120 positioned outside the cathode 40 .
  • the first outer frame portion 110 includes a first outer frame 111 , a water inlet 112 positioned at one side of the first outer frame 111 , and an oxygen outlet 113 positioned at the other side of the first outer frame 111 .
  • the second outer frame portion 120 includes a second outer frame 121 , an oxygen inlet 122 positioned at one side of the second outer frame 121 , and a water outlet 123 positioned at the other side of the second outer frame 121 .
  • oxygen may be supplied to the cathode 40 through the oxygen inlet 122 , oxygen (O 2 ) in air supplied from the air supply unit (not shown) reacts with hydrogen ions (H + ) being moved by passing through the electrolyte membrane 50 to generate water (H 2 O) at the cathode, and the generated water (H 2 O) may be discharged through the water outlet 123 .
  • water (H 2 O) generated at the cathode 40 may be collected in the water supply source 70 through the water collection line 90 or may be discharged through any discharge line.
  • the application example 100 of the oxygen generator according to the present invention includes a gasket 130 positioned between the first outer frame portion 110 and the second outer frame portion 120 .
  • the gasket 130 includes a gasket frame 131 coupled to the first outer frame portion 110 and the second outer frame portion 120 and a hollow portion 132 formed inside the gasket frame 131 .
  • the gasket frame 131 may be made of Teflon or silicon.
  • the membrane-electrode assembly 60 including the anode 30 , the cathode 40 , and the electrolyte membrane 50 provided between the anode and the cathode may be positioned in the hollow portion 132 .
  • the gasket 130 may support the membrane-electrode assembly 60 and may also prevent water supplied to the membrane-electrode assembly 60 or water generated in the membrane-electrode assembly 60 from flowing to the outside.
  • the anode 30 may include a first support, a first catalyst layer positioned at one side of the first support, and a first gas diffusion layer positioned at the other side of the first support.
  • the first support may include carbon black, Ketjen black, acetylene black, an activated carbon powder, a carbon molecular sieve, carbon nanotubes, activated carbon having fine pores, mesoporous carbon, a conductive polymer, or a mixture thereof.
  • the first catalyst layer may include at least one catalyst for an OER selected from the group consisting of metals including platinum (Pt), iridium (Ir), ruthenium (Ru), nickel (Ni), manganese (Mn), cobalt (Co), iron (Fe), titanium (Ti), rhenium (Re), niobium (Nb), vanadium (V), sulfur (S), and molybdenum (Mo) and the metals combined with an oxide, a nitride, a carbide, a phosphide, and a sulfide.
  • the first catalyst layer may be in a state of being supported on the first support.
  • the cathode 40 may include a second support, a second catalyst layer positioned at one side of the second support, and a second gas diffusion layer positioned at the other side of the second support.
  • the second support may include at least one material selected from the group consisting of carbon or transition metals combined with an oxide, a nitride, a carbide, a phosphide, and a sulfide.
  • the second catalyst layer may include at least one catalyst for an ORR selected from the group consisting of Pt, palladium (Pd), Ir, gold (Au), silver (Ag), and an alloy thereof.
  • the second catalyst layer may be in a state of being supported on the second support.
  • the alloy of Pt, Pd, Ir, Au, and Ag may be an alloy of a metal selected from the group consisting of Pt, Pd, Ir, Au, and Ag with a transition metal, an alkali metal, or a lanthanide group metal.
  • the transition metal may be at least one selected from the group consisting of scandium (Sc), Ti, V, chromium (Cr), Mn, Fe, Co, Ni, copper (Cu), zinc (Zn), zirconium (Zr), Nb, Mo, technetium (Tc), Ru, rhodium (Rh), hafnium (Hf), tantalum (Ta), tungsten (W), Re, and osmium (Os).
  • the alkali metal may be at least one selected from the group consisting of potassium (K), rubidium (Rb), cesium (Cs), beryllium (Be), magnesium (Mg), calcium (Ca), chromium (Cr), barium (Ba), and radium (Ra).
  • the lanthanide group metal may be at least one selected from the group consisting of lanthanum (La), yttrium (Y), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), ytterbium (Yb), and lutetium (Lu).
  • La lanthanum
  • Y cerium
  • Pr praseodymium
  • Nd neodymium
  • Pm promethium
  • Sm samarium
  • Eu europium
  • Gd gadolinium
  • Tb terbium
  • Dy dysprosium
  • Yb ytterbium
  • Lu lutetium
  • the second catalyst layer which includes a catalyst for a cathode, may use an Fe—N—C catalyst, and the Fe—N—C catalyst may inhibit an HER and promote an ORR, that is, an HER may not occur.
  • the Fe—N—C catalyst may be used throughout a wide range of potentials.
  • the first gas diffusion layer and the second gas diffusion layer function to allow a reaction gas to easily access the catalyst layer.
  • the first gas diffusion layer of the anode should function to allow water supplied from the water supply unit to pass therethrough
  • the second gas diffusion layer of the cathode should function to allow oxygen supplied from the air supply unit to pass therethrough.
  • the gas diffusion layer is not particularly limited, and for example, the gas diffusion layer may include carbon paper, carbon cloth, or a metal sheet having in a mesh form.
  • the metal sheet in the mesh form may be a stainless steel-based mesh, a titanium-based mesh, or a nickel-based mesh.
  • the materials of the first gas diffusion layer and the second gas diffusion layer are not limited in the present invention.
  • the electrolyte membrane 50 may include at least one selected from the group consisting of a perfluoro-based proton conductive polymer membrane, a sulfonated polysulfone copolymer, a sulfonated poly(ether-ketone)-based polymer, a perfluorinated sulfonic acid group-containing polymer, a sulfonated polyether ether ketone-based polymer, a polyimide-based polymer, a polystyrene-based polymer, a polysulfone-based polymer, and a clay-sulfonated polysulfone nanocomposite.
  • the electrolyte membrane may include an aqueous solvent, and the aqueous solvent may be at least one selected from H 2 SO 4 , HClO 4 , K 2 SO 4 , Na 2 SO 4 , H 3 PO 4 , H 4 P 2 O 7 , K 2 PO 4 , Na 3 PO 4 , K 3 PO 4 , HNO 3 , KNO 3 , and NaNO 3 .
  • the bonding of the anode, the cathode, and the electrolyte membrane is required, and such bonding may be performed through a thermal pressing method or the like.
  • a thermal press bonding process may be performed at a temperature ranging from of 120° C. to 150° C. and a pressure ranging from 50 kgf/cm 2 to 200 kgf/cm 2 for 0.1 minutes to 10 minutes.
  • Pt/C as a catalyst was applied on a cathode, and an iridium oxide catalyst having a nanoporous structure was applied on an anode using a spray method, a decal method, or the like.
  • Pt/C—IrO 2 Air-Water
  • IrO 2 air-Water
  • a nafion electrolyte membrane platinum as a catalyst was applied on a cathode, and an iridium oxide catalyst having a nanoporous structure was applied on an anode using a spray method, a decal method, or the like.
  • unit cell evaluation was performed in the same manner as in Experiment Example 1 described above except that the supply of water to the anode through a water supply source was cut off and the supply of air to the cathode through an air supply unit was cut off.
  • Pt/C—IrO 2 Non Air-Water
  • Pt/C was used as a cathode catalyst
  • IrO 2 was used as an anode catalyst
  • the supply of water to the anode through the water supply source was cut off
  • the supply of air to the cathode through the air supply unit was cut off.
  • unit cell evaluation was performed in the same manner as in Experiment Example 1 described above except that the supply of air to the cathode through an air supply unit was cut off.
  • Pt/C—IrO 2 Non Air-Water
  • a nafion electrolyte membrane platinum as a catalyst was applied on a cathode, and an iridium oxide catalyst having a nanoporous structure was applied on an anode using a spray method, a decal method, or the like.
  • Water was supplied to the anode through a water supply source, but the supply of air to the cathode was cut off and a voltage was applied up to 1.8 V to perform unit cell evaluation.
  • FIG. 8 is a graph showing a change in oxygen generation current density according to a voltage of Experimental Example 4.
  • Experimental Example 4 showed a contrasting result with Example 1 in that when air was supplied to the cathode through the separate air supply unit and water was supplied to the anode through the separate water supply source, current density was obtained even when a voltage of 0.6 V or more was applied. In addition, it was confirmed that an OER occurred at the anode in Experimental Example 1 and an HER occurred at the cathode in Experimental Example 4.
  • FIG. 9 is a graph showing a change in oxygen generation current density according to a flow rate of air of Experimental Example 5.
  • a supply flow rate of air through the air supply unit may be 20 ccm or more.
  • FIG. 10 is a graph showing a change in oxygen generation current density according to a voltage of Experimental Example 6.
  • Unit cell evaluation was performed in the same manner as in Experimental Example 1 except that platinum as a catalyst was used at a cathode and the same platinum catalyst as the cathode was used at an anode.
  • unit cell evaluation was performed by being divided into a case (1) in which water was supplied to the anode through a water supply source and air was supplied to the cathode through an air supply unit (Air-Water) and a case (2) in which water was supplied to the anode through the water supply source but the air supply unit was blocked and thus air was not supplied to the cathode (Non Air-Water).
  • FIG. 11 is a graph showing a change in oxygen generation current density according to a voltage of Experimental Example 7.
  • Unit cell evaluation was performed in the same manner as in Experimental Example 1 except that platinum as a catalyst was used at a cathode and a ruthenium oxide catalyst was used at an anode.
  • water was supplied to the anode through a water supply source, and air was supplied to the cathode through an air supply unit to perform unit cell evaluation.
  • FIG. 12 is a graph showing a change in oxygen generation current density according to a voltage of Experimental Example 8.
  • an amount of oxygen generated at the anode may be increased by varying a catalyst of the anode.
  • an oxygen generator for generating oxygen (O 2 ) using a simple configuration including a membrane-electrode assembly 60 , a power supply 20 capable of applying a certain amount of power, a water supply source 70 capable of supplying water to an anode of the membrane-electrode assembly, and an air supply unit 80 for supplying oxygen to a cathode of the membrane-electrode assembly.
  • an electrochemical oxygen generator can be provided such that oxygen is generated without noise and vibration using an electrochemical method and the electrochemical oxygen generator is miniaturized due to a simple device configuration.

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114481213A (zh) * 2022-02-25 2022-05-13 同济大学 一种低温磷化铂镍纳米合金团簇/碳催化剂及制备与应用
US20220356096A1 (en) * 2021-05-06 2022-11-10 Prosper Technologies, Llc Systems of gas infusion for wastewater treatment

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109111012B (zh) * 2018-11-09 2021-05-28 济南大学 一种便携式净水器
JP2023529463A (ja) * 2020-06-10 2023-07-10 ネーデルランツェ・オルガニザーティ・フォール・トゥーヘパストナトゥールウェテンシャッペレイク・オンダーズーク・テーエヌオー プロトン交換膜型電解槽デバイス及び該デバイスを製造する方法
KR102437608B1 (ko) * 2020-10-13 2022-08-29 한국에너지기술연구원 중성 pH 영역에서 활성화 가능한 애노드 및 이의 제조방법 그리고 이를 포함하는 미생물 전기합성 시스템
CN114164439B (zh) * 2021-12-08 2022-11-29 嘉庚创新实验室 电化学反应装置及生产氧气的方法

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20180241047A1 (en) * 2015-09-11 2018-08-23 Centre National De La Recherche Scientifique P/metal-n-c hybrid catalyst
US20180358641A1 (en) * 2015-05-26 2018-12-13 3M Innovative Properties Company Electrode membrane assembly having an oxygen evolution catalyst electrodes, and methods of making and using the same

Family Cites Families (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1065005C (zh) * 1995-10-13 2001-04-25 武汉中山实业(集团)股份有限公司 电化学氧阴极制氧方法及其电解槽
JPH09155157A (ja) * 1995-12-11 1997-06-17 Opt D D Melco Lab:Kk 電気化学素子
DE10053546A1 (de) * 2000-10-27 2002-05-02 Angewandte Technik Mbh Greifsw Portabler elektrochemischer Sauerstoffgenerator
US6838205B2 (en) * 2001-10-10 2005-01-04 Lynntech, Inc. Bifunctional catalytic electrode
KR100717747B1 (ko) * 2005-10-25 2007-05-11 삼성에스디아이 주식회사 직접 산화형 연료 전지용 스택의 회복 방법
US8021525B2 (en) * 2007-05-16 2011-09-20 Commonwealth Scientific And Industrial Research Organisation PEM water electrolysis for oxygen generation method and apparatus
US8617770B2 (en) * 2007-09-12 2013-12-31 GM Global Technology Operations LLC Electrodes containing oxygen evolution reaction catalysts
KR101600963B1 (ko) * 2010-04-15 2016-03-08 충북대학교 산학협력단 고농도 산소 발생장치
KR101326120B1 (ko) * 2010-08-18 2013-11-06 (주)엘켐텍 전기분해모듈 및 이를 포함하는 산소 발생기
WO2013089026A1 (ja) * 2011-12-12 2013-06-20 パナソニック株式会社 炭素系材料、電極触媒、酸素還元電極触媒、ガス拡散電極、水溶液電解装置、並びに炭素系材料の製造方法
US9257705B2 (en) * 2014-03-25 2016-02-09 King Fahd University Of Petroleum And Minerals Method for producing Pt-free electrocatalysts for fuel cells and batteries
KR101564608B1 (ko) * 2014-04-10 2015-11-02 국립대학법인 울산과학기술대학교 산학협력단 수소 및 산소를 생성하는 고체 산화물 수전해 셀
GB201515869D0 (en) * 2015-09-08 2015-10-21 Johnson Matthey Fuel Cells Ltd Oxygen reduction reactor catalyst
JP7349354B2 (ja) * 2016-09-08 2023-09-22 セルセントリック・ゲーエムベーハー・ウント・コー・カーゲー 燃料電池システムのための氷点下始動方法

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20180358641A1 (en) * 2015-05-26 2018-12-13 3M Innovative Properties Company Electrode membrane assembly having an oxygen evolution catalyst electrodes, and methods of making and using the same
US20180241047A1 (en) * 2015-09-11 2018-08-23 Centre National De La Recherche Scientifique P/metal-n-c hybrid catalyst

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20220356096A1 (en) * 2021-05-06 2022-11-10 Prosper Technologies, Llc Systems of gas infusion for wastewater treatment
US20220356093A1 (en) 2021-05-06 2022-11-10 Prosper Technologies, Llc Systems of gas infusion for wastewater treatment
US11643344B2 (en) 2021-05-06 2023-05-09 Prosper Technologies, Llc Methods of gas infusion for wastewater treatment
US11697606B2 (en) 2021-05-06 2023-07-11 Prosper Technologies, Llc Systems of gas infusion for wastewater treatment
US11795081B2 (en) * 2021-05-06 2023-10-24 Prosper Technologies, Llc Systems of gas infusion for wastewater treatment
US12006239B2 (en) 2021-05-06 2024-06-11 Prosper Technologies, Llc Oxygen infusion module for wastewater treatment
CN114481213A (zh) * 2022-02-25 2022-05-13 同济大学 一种低温磷化铂镍纳米合金团簇/碳催化剂及制备与应用

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