WO2012160957A1 - Catalyseur d'électrode et procédé de production de celui-ci - Google Patents

Catalyseur d'électrode et procédé de production de celui-ci Download PDF

Info

Publication number
WO2012160957A1
WO2012160957A1 PCT/JP2012/061722 JP2012061722W WO2012160957A1 WO 2012160957 A1 WO2012160957 A1 WO 2012160957A1 JP 2012061722 W JP2012061722 W JP 2012061722W WO 2012160957 A1 WO2012160957 A1 WO 2012160957A1
Authority
WO
WIPO (PCT)
Prior art keywords
electrode
catalyst
polymer
metal
diaminopyridine
Prior art date
Application number
PCT/JP2012/061722
Other languages
English (en)
Japanese (ja)
Inventor
橋本　和仁
一哉 渡邉
勇 趙
和秀 神谷
周次 中西
理生 鈴鹿
亮 釜井
Original Assignee
国立大学法人東京大学
パナソニック株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 国立大学法人東京大学, パナソニック株式会社 filed Critical 国立大学法人東京大学
Publication of WO2012160957A1 publication Critical patent/WO2012160957A1/fr

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/16—Biochemical fuel cells, i.e. cells in which microorganisms function as catalysts
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
    • H01M4/88—Processes of manufacture
    • H01M4/8878—Treatment steps after deposition of the catalytic active composition or after shaping of the electrode being free-standing body
    • H01M4/8882—Heat treatment, e.g. drying, baking
    • H01M4/8885—Sintering or firing
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
    • H01M4/90—Selection of catalytic material
    • H01M4/9041—Metals or alloys
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
    • H01M4/90—Selection of catalytic material
    • H01M4/9091—Unsupported catalytic particles; loose particulate catalytic materials, e.g. in fluidised state
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/10—Fuel cells with solid electrolytes
    • H01M2008/1095—Fuel cells with polymeric electrolytes
    • 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
    • Y02E60/50—Fuel cells

Definitions

  • the present invention relates to an electrode catalyst and a production method thereof, a gas diffusion electrode containing the catalyst, and a fuel cell using the same.
  • Fuel cells are attracting attention as a new energy system that replaces conventional fossil fuels.
  • Fuel cells include hydrogen as an electron donor, such as polymer electrolyte fuel cells (hereinafter referred to as “PEFC”) and phosphoric acid fuel cells (hereinafter referred to as “PAFC”).
  • PEFC polymer electrolyte fuel cells
  • PAFC phosphoric acid fuel cells
  • MFC microbial fuel cell
  • An electrode catalyst is included in the cathode (air electrode), and hydrogen gas and / or oxygen gas is ionized by the catalytic action.
  • a platinum catalyst such as platinum (Pt) or a platinum alloy is generally known, and the catalyst component supported on a carbon carrier (platinum-supported carbon) is gas diffused. Widely used as an electrode (electrode for fuel cell).
  • Pt is an expensive and rare metal, it not only hinders the spread of fuel cells to consumer use, but also has a problem with the amount of resources that can be used for future mass production. is there.
  • Patent Documents 1 and 2 and Non-Patent Documents 1 and 2 disclose electrode catalysts based on metal complexes composed of a polymer and a catalyst metal as Pt substitute catalysts.
  • a catalyst component and an indole, isoindole, naphthopyrrole, pyrrolopyridine, benzimidazole, purine, carbazole, phenoxazine, and phenothiazine are selected as an electrocatalyst having a high catalytic activity and a long life.
  • An electrode catalyst comprising a non-platinum type conductive polymer metal complex comprising a conductive polymer having at least one repeating unit structure and a metal ion, and a gas diffusion electrode using the same are disclosed.
  • Patent Document 2 it has a high specific surface area, contains two or more chemical structures selected from —NH 2 , ⁇ NH, and ⁇ N— in the molecule, and has a planar structure and a metal.
  • a fuel cell catalyst obtained by heat-treating a coordination polymer metal complex having a porous skeleton structure is disclosed.
  • Non-Patent Document 1 discloses an invention in which an iron (II) phthalocyanine (FePc) and cobalt-tetramethoxyphenylporphyrin (Cobalt ⁇ ⁇ TetraMethoxyPhenylPorphyrin, hereinafter referred to as “CoTMPP”)-based oxygen reduction catalyst is used as an MFC cathode.
  • an iron (II) phthalocyanine (FePc) and cobalt-tetramethoxyphenylporphyrin (Cobalt ⁇ ⁇ TetraMethoxyPhenylPorphyrin, hereinafter referred to as “CoTMPP”)-based oxygen reduction catalyst is used as an MFC cathode.
  • Non-Patent Document 2 the performance of proton-conducting ion exchange membranes can be achieved by using Co-polypyrrole doped with 4-toluenesulfonic acid (Cobalt PolyPyrrole; hereinafter referred to as “CoPPy”) as a platinum substitute catalyst for the cathode of PEFC.
  • CoPPy Co-polypyrrole doped with 4-toluenesulfonic acid
  • Non-patent Document 2 In metal complexes, metal atoms are generally more easily coordinated with nitrogen atoms (N), and the greater the number of N atoms that can function as a ligand in the polymer, the more the catalyst activity improves. Attempts have been made to increase (Non-patent Document 2). However, in the metal complex of the above prior art, it cannot be said that the number of N atoms serving as a ligand in the polymer is necessarily large due to the structure of the monomer constituting the polymer.
  • the present invention has an oxygen reduction reaction (Oxygen Reduction Reaction; hereinafter referred to as “ORR”) catalytic activity, durability and corrosion resistance equivalent to or higher than that of a Pt-based catalyst, and is inexpensive and stable. It is an object of the present invention to provide an electrocatalyst that can be supplied automatically, a gas diffusion electrode using the electrode catalyst, and a fuel cell having the energy conversion efficiency, long life, and low cost provided with the electrode.
  • ORR oxygen reduction reaction
  • the present inventors have developed a new electrode catalyst in order to solve the above problems.
  • an electrode using a metal complex composed of a diaminopyridine polymer and a catalyst metal as a catalyst component has higher energy conversion efficiency than a Pt electrode and can generate a high output current.
  • the diaminopyridine polymer has a larger number of nitrogen atoms that can serve as a ligand than the conventional polymer metal complex, and it is considered that a larger number of catalyst metals can be coordinated to bring about the above effect.
  • the invention is based on the findings, and specifically provides the following inventions.
  • the manufacturing method of the electrode catalyst including the 3rd process of obtaining a complex.
  • the molar ratio of 1 or 2 or more selected from the group consisting of diaminopyridine, diaminopyridine derivative, triaminopyridine, triaminopyridine derivative, tetraaminopyridine and tetraaminopyridine derivative to the catalytic metal atom is 3:
  • a gas diffusion electrode comprising a conductive carrier carrying the electrode catalyst according to any one of (1) to (7) and (15).
  • a fuel cell comprising the gas diffusion electrode according to any one of (16) to (18).
  • the electrocatalyst of the present invention can provide an inexpensive electrocatalyst having an ORR catalytic activity, durability and corrosion resistance equivalent to or higher than that of the current mainstream Pt-based catalyst.
  • an electrocatalyst having an ORR catalyst activity, durability, and corrosion resistance equivalent to or higher than that of a conventional electrocatalyst can be produced at a low cost.
  • the gas diffusion electrode of the present invention it is possible to provide a gas diffusion electrode that has high catalytic activity, durability and corrosion resistance, and can be stably supplied at low cost.
  • the fuel cell of the present invention it is possible to provide a fuel cell with high energy conversion efficiency, long life and low cost.
  • each electrode catalyst obtained by calcining a polymer metal complex composed of 2,6-diaminopyridine polymer and cobalt nitrate mixed at different mixing ratios is shown. It is a figure which shows the comparison of ORR catalyst activity by RRDE (rotating ring disk electrode) provided with the electrode catalyst.
  • RRDE contains CoDAPP (Co-2,6-diaminopyridine polymer), CoTMPP, CoPPy and Pt electrocatalysts.
  • A shows a CoDAPP catalyst
  • (b) shows a CoTMPP catalyst
  • (c) shows a CoPPy catalyst
  • (d) shows a Pt catalyst.
  • a gas diffusion electrode (CoDAPP electrode) containing a CoDAPP catalyst (b) a gas diffusion electrode (CoTMPP electrode) containing a CoTMPP catalyst, and (c) a gas diffusion electrode (CoPPy electrode) containing a CoPPy catalyst.
  • D show gas diffusion electrodes (Pt electrodes) each containing a Pt catalyst. The power density of MFC when each gas diffusion electrode is used as a cathode is shown.
  • the polarization curves of each gas diffusion electrode measured using an Ag / AgCl electrode as a reference electrode are shown in (a) and (a ′), respectively, when the CoDAPP electrode is used as the cathode, ) And (b ′) show the performance of the anode and the cathode, respectively, when the CoTMPP electrode is used as the cathode, and (c) and (c ′) show the performance of the anode and the cathode, respectively, when the CoPPy electrode is used as the cathode. (D) and (d ′) show the performance of the anode and the cathode, respectively, when the Pt electrode is used as the cathode.
  • FIG. 6 is a polarization curve diagram showing a comparison of ORR catalytic activity at pH 7 of RRDE equipped with electrocatalysts having different catalytic metals.
  • A shows the CoDAPP catalyst
  • (b) shows the FeDAPP catalyst
  • (c) shows the Fe / CoDAPP catalyst.
  • (A) shows the CoDAPP catalyst
  • (b) shows the FeDAPP catalyst
  • (c) shows the Fe / CoDAPP catalyst.
  • Electrode catalyst 1-1 Outline
  • summary The 1st Embodiment of this invention is an electrode catalyst.
  • the electrode catalyst of the present invention is characterized by having a specific metal complex as a catalyst component and having the same or higher ORR catalyst activity, durability and corrosion resistance as compared with conventional electrode catalysts such as Pt-based catalysts.
  • the electrode catalyst of the present invention contains, as a catalyst component, 1) a metal complex having specific physical properties, or 2) a metal complex formed by firing a specific polymer metal complex.
  • the configuration of the electrode catalyst of the present invention will be specifically described below.
  • the “metal complex” refers to a compound comprising a polymer and / or a modified product thereof and a catalytic metal, wherein a ligand in the polymer or the modified product is coordinated with the catalytic metal.
  • fired metal complex refers to a compound obtained by firing a polymer metal complex.
  • “Baking (treatment)” here refers to a heat treatment at a high temperature.
  • the “polymer metal complex” refers to the metal complex in a state where no baking treatment is performed.
  • the fired metal complex and the polymer metal complex are comprehensively referred to regardless of whether or not the firing treatment has been completed.
  • the essential component functioning as a catalyst component is, as will be described later, a specific polymer and / or a modified product thereof, and a metal complex composed of a catalytic metal, or a specific polymer and a catalyst.
  • these metal complexes that are essential components in the electrode catalyst of the present invention are collectively referred to as “2-4 aminopyridine polymer metal complexes”.
  • 2-4 aminopyridine polymer means a monomer diaminopyridine (C 5 H 7 N 3 ), diaminopyridine derivative, triaminopyridine (C 5 H 8 N 4 ), triaminopyridine derivative, It is a general name for compounds in which one or more selected from the group consisting of tetraaminopyridine (C 5 H 9 N 5 ) and tetraaminopyridine derivatives are polymerized.
  • the term “polymer” means “2-4 aminopyridine polymer” unless otherwise specified.
  • the “modified product” is a modified product of the polymer, and refers to a compound, an oligomer, and the like generated by thermal decomposition of the polymer when the polymer metal complex is baked.
  • the diaminopyridine, triaminopyridine and tetraaminopyridine are compounds in which the hydrogen atom (H) of pyridine (C 5 H 5 N) is substituted with 2 , 3 and 4 amino groups (—NH 2 ), respectively.
  • the monomer constituting the 2-4 aminopyridine polymer may be composed of only one kind or a combination of two or more kinds.
  • Diaminopyridine has positional isomers of 2, 3-diaminopyridine, 2, 4-diaminopyridine, 2, 5-diaminopyridine, 2, 6-diaminopyridine and 3, 4-diaminopyridine, and triaminopyridine has 2, 3, 4-triaminopyridine, 2, 3, 5-triaminopyridine, 2, 3, 6-triaminopyridine, 2, 4, 5-triaminopyridine, 2, 4, 6-triaminopyridine And 3, 4, 5-triaminopyridine, and tetraaminopyridine includes 2, 3, 4, 5-tetraaminopyridine, 2, 4, 5, 6-tetraaminopyridine and 2, 3 , 5, 6-tetraaminopyridine positional isomers are known, but each monomer constituting the 2-4 aminopyridine polymer may be any positional isomer. Moreover, it may be composed only of the same positional isomers, or may be composed of two or more different positional isomers.
  • examples of the derivatives of diaminopyridine include 4 methyl-2, 6-diaminopyridine, 4 ethyl-2, 6-diaminopyridine and 3methyl-2, 6-diaminopyridine.
  • Examples of the derivative of triaminopyridine include 3methyl-2, 3, 6-triaminopyridine and 3ethyl-2, 3, 6-triaminopyridine.
  • Tetraaminopyridine derivatives include, for example, 4N methylamino-2, 3, 6-triaminopyridine, 4N methylamino-2, 4, 6-triaminopyridine and 4N, N diamino-2, 3, 6-triaminopyridine. Aminopyridine is mentioned.
  • the arrangement of the respective monomers and / or positional isomers in the 2-4 aminopyridine polymer is a polymerization.
  • it may be polymerized so that a combination of specific monomers is regularly repeated, or may be polymerized randomly.
  • the ligand included in the 2-4 aminopyridine polymer coordinates the catalyst metal.
  • the atom (coordinating atom) that can be a ligand in the polymer include a nitrogen atom of a pyridine ring and / or a nitrogen atom of an amino group.
  • diaminopyridine and derivatives thereof, triaminopyridine and derivatives thereof, and tetraaminopyridine and derivatives thereof include three, four, and five nitrogen atoms, respectively, that can be ligands. . Therefore, the 2-4 aminopyridine polymer composed of these monomers has a high nitrogen atom content.
  • the electrocatalyst of the present invention can have high ORR catalytic activity.
  • diaminopyridine polymer in which only diaminopyridine is polymerized can be mentioned.
  • the positional isomer constituting the diaminopyridine polymer is not limited, but 2,6-diaminopyridine and / or 2,3-diaminopyridine are preferable. These positional isomers are because the nitrogen atoms (N) are arranged closest to each other in the molecule, so that the catalytic metal can be coordinated more stably in the polymer.
  • a more preferred diaminopyridine polymer is a 2,6-diaminopyridine polymer in which only 2,6-diaminopyridine monomer is polymerized.
  • the chemical polymerization reaction for linking the monomers constituting the 2-4 aminopyridine polymer is not limited, but is preferably anionic polymerization.
  • the polymer is a 2,6-diaminopyridine polymer
  • the polymer contains, for example, a chemical structure represented by the following formula (I) and / or (II) by anionic polymerization of 2,6-diaminopyridine. Is expected.
  • the “catalytic metal” is a metal atom or metal ion coordinated in a metal complex.
  • the catalyst metal is not particularly limited, but is preferably a transition metal. Specifically, for example, titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zirconium (Zr ), Niobium (Nb), molybdenum (Mo), ruthenium (Ru), rhodium (Rh), palladium (Pd), silver (Ag), hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re ), Osnium (Os), iridium (Ir), Pt, gold (Au), and the like or ions thereof.
  • the catalyst metal is preferably Cr, Mn, Fe, Co, Ni, and Cu.
  • the metal complex may coordinate one type of catalyst metal, or may coordinate two or more different catalyst metals.
  • An example is a metal complex in which Fe and Co are coordinated.
  • Pt and Au are rare and expensive, it seems to be contrary to the purpose of the present invention, but by using them coordinated in a metal complex, the amount of Pt used compared to known Pt-based catalysts Therefore, the object of the present invention can be achieved. Therefore, it can be included in the catalyst metal in the present invention.
  • a 2,6-diaminopyridine polymer is a metal complex in which cobalt is coordinated as a catalytic metal (Co-2,6-diaminopyridine polymer; Co-2,6-diaminopyridine polymer,
  • it is expected to include, for example, a structure represented by the following formula (III) in the case of “CoDAPP”.
  • Me represents a catalyst metal (Co in this example).
  • the 2-4 aminopyridine polymer metal complex of the present invention is preferably obtained by baking a polymer metal complex. This is because the catalyst metal in the polymer metal complex is stably coordinated to the nitrogen atom by the calcination treatment, and as a result, stable catalytic activity, high durability, and corrosion resistance can be obtained by chemical curing.
  • the mixing ratio of the 2-4 aminopyridine polymer to the catalyst metal salt in the 2-4 aminopyridine polymer metal complex is 3: 1 to 5: 1, preferably 3.5: 1 to 4.5, as the molar ratio of the raw material monomer to the catalyst metal atom. : Select to be 1. Even when two or more different catalyst metals are used, the molar ratio of the raw material monomers to the total catalyst metal atoms may be within the above range.
  • the molar ratio between different catalytic metals is not particularly limited. What is necessary is just to determine suitably according to the kind etc. of the catalyst metal to be used. For example, when using Co and Fe, the molar ratio of Co and Fe may be selected within a range of 1: 0.1 to 1:10.
  • the “calcination temperature” for the calcination treatment is 650 to 800 ° C., preferably 680 to 780 ° C., more preferably 690 to 760 ° C., further preferably 700 to 750 ° C.
  • the firing treatment can be performed by a known method for heat-treating the electrode catalyst.
  • the dried polymer metal complex powder may be calcined at a calcining temperature for 30 minutes to 5 hours, preferably 1 hour to 2 hours in a reducing gas atmosphere or an inert gas atmosphere.
  • the firing is performed in a reducing gas atmosphere.
  • ammonia can be used as the reducing gas.
  • the inert gas for example, nitrogen can be used.
  • nitrogen doping is generally not performed only by firing the carbon material in an inert gas atmosphere.
  • the object can be achieved even by firing in an inert gas atmosphere.
  • it may be further fired in a reducing gas atmosphere.
  • the “specific physical properties” are physical properties exhibited by the 2-4 aminopyridine polymer metal complex in the present invention.
  • the catalyst metal nitrogen in the polymer metal complex A property that satisfies at least one of the following (i) to (iii) obtained as a result of stabilization of coordination to an atom.
  • Element ratio of nitrogen (N) / carbon (C) is 0.11 or more in molar ratio
  • Element ratio of catalyst metal (Metal) / nitrogen (N) is 0.03 or more in molar ratio, preferably (Iii)
  • the content of the catalyst metal coordinated to the nitrogen atom is 0.05 or more and 0.4 mol% or more, and the content of the nitrogen atom is 6.0 mol% or more.
  • Each content of the catalyst metal coordinated to carbon, nitrogen, and nitrogen atom in the electrode catalyst is measured by X-ray photoelectron spectroscopy. All the content rates are their ratios when the metal complex is used as a reference (when the metal complex is 100 mol%).
  • Calcination may cause a part of the 2-4 aminopyridine polymer to be modified, and the polymer form may be lost.
  • Such modification is permissible as long as the calcined metal complex can be used as an electrocatalyst, and therefore the 2-4 aminopyridine polymer metal complex constituting the electrocatalyst of the present invention is calcined with 2-4 aminopyridine polymer. May contain a modified material.
  • the shape of the fired metal complex is not particularly limited. However, it is preferable that the specific surface area per unit area of the electrode catalyst supported on the electrode surface is large. This is because the catalytic activity (mass activity) per unit mass of the electrode can be further increased. Therefore, a preferable shape is a particle shape, particularly a powder shape.
  • the specific surface area of the calcined metal complex is preferably 500 m 2 / g or more, more preferably 550 m 2 / g or more. Such a specific surface area can be measured by a nitrogen BET adsorption method or the like.
  • the conductivity of the electrode catalyst is preferably in the range of 0.1 s / cm to 10 s / cm.
  • the electrode catalyst of the present invention can contain a catalyst component other than the calcined metal complex.
  • a catalyst component other than the calcined metal complex.
  • a known catalyst such as a CoTMPP catalyst may be included.
  • the 2nd Embodiment of this invention is a manufacturing method of an electrode catalyst. This manufacturing method can manufacture the electrode catalyst as described in the first embodiment at a low cost.
  • the production method of the present invention includes (a) a polymerization step, (b) a polymer metal complex formation step, and (c) a firing step.
  • a polymerization step includes (a) a polymerization step, (b) a polymer metal complex formation step, and (c) a firing step.
  • the “polymerization step” is a step of synthesizing a 2-4 aminopyridine polymer by anionic polymerization of diaminopyridine, triaminopyridine and / or tetraaminopyridine.
  • the monomer to be polymerized only one kind may be used, or two or three kinds may be combined.
  • the mixing molar ratio of each monomer there is no particular limitation on the mixing molar ratio of each monomer.
  • Those skilled in the art may appropriately determine the catalytic activity.
  • An example of a preferred monomer used in the polymerization step is the case of diaminopyridine alone.
  • the positional isomer of each monomer used for polymerization is not particularly limited, but preferably a positional isomer in which a nitrogen atom serving as a ligand in the monomer molecule is located proximally.
  • a positional isomer in which a nitrogen atom serving as a ligand in the monomer molecule is located proximally is preferable.
  • the monomer is polymerized by an anionic polymerization reaction.
  • the anionic polymerization reaction may be performed using a known method commonly used in the art. For example, a strong base solution is allowed to act on the monomer to deprotonate it, and each monomer is polymerized using the generated carbanion as a nucleophile.
  • a strong base solution is allowed to act on the monomer to deprotonate it, and each monomer is polymerized using the generated carbanion as a nucleophile.
  • the base used in the strong base solution for example, sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide and the like can be used.
  • the polymerization temperature and polymerization time are not particularly limited as long as the reaction proceeds. Usually, this step can be achieved by reacting at a temperature of 5 to 40 ° C. for about 5 to 48 hours.
  • the recovered 2-4 aminopyridine polymer is preferably washed with water (including deionized water and distilled water) and then dried and used in the subsequent steps.
  • the following polymer metal complex formation step can be started without passing through this step.
  • Polymer metal complex formation step refers to the formation of a polymer metal complex by coordinating a catalyst metal to the polymer by mixing a 2-4 aminopyridine polymer and a catalyst metal salt. It is a process. The nitrogen atom contained in the 2-4 aminopyridine polymer becomes a ligand (coordinating atom) and coordinates with the catalytic metal to form a polymer metal complex.
  • Catalytic metal salt is a salt of a catalytic metal to be coordinated in a metal complex, and specifically includes a catalytic metal hydrochloride, sulfate, nitrate, phosphate, acetate, and the like.
  • the catalyst metal in this step is not particularly limited as long as it is a metal having catalytic activity in the electrode catalyst, but is preferably a transition metal. Specifically, for example, the transition metals described in the first embodiment can be mentioned.
  • salts of Cr, Mn, Fe, Co, Ni and Cu are suitable as the catalyst metal salt in this step, and a catalyst metal salt of Fe or Co is particularly preferable. Specific examples include iron chloride, iron nitrate, iron sulfide, cobalt nitrate, cobalt chloride, and cobalt sulfide.
  • the mixing ratio of the 2-4 aminopyridine polymer and the catalytic metal salt may be selected so that the molar ratio of the raw material monomer to the catalytic metal atom is 3: 1 to 5: 1, preferably 3.5: 1 to 4.5: 1. . That is, the mass of the polymer and the catalyst metal salt is selected so that (the number of moles of the repeating unit constituting the polymer) :( the number of moles of the metal contained in the catalyst metal salt) is within the above preferable range. What is necessary is just to mix a metal salt.
  • the catalyst metal or its ion can be coordinated in the 2-4 aminopyridine polymer by mixing and suspending these in a suitable solvent and further stirring sufficiently.
  • water, ethanol, propanol or a mixed solution thereof for example, water and ethanol or a mixed solution of water and (iso) propanol can be used.
  • the mixing temperature and mixing time are not particularly limited as long as the reaction proceeds. Usually, this reaction can be achieved by reaction at a temperature of 50 to 70 ° C. for about 30 minutes to 5 hours. Ultrasonic mixing may be performed in order to sufficiently mix the two substances.
  • the formed polymer metal complex precipitates as a solid in the solvent.
  • the solvent is removed by centrifugation, filtration or evaporation, and the target polymer metal complex is recovered.
  • the target polymer metal complex In order to remove uncoordinated catalyst metal, etc., it may be washed with water (including deionized water and distilled water).
  • the recovered polymer metal complex may be pulverized as necessary using, for example, a quartz mortar.
  • the “firing step” refers to firing the polymer metal complex obtained in the polymer metal complex forming step at a high temperature in a reducing gas atmosphere or an inert gas atmosphere. It is a process to obtain. By this step, the catalyst metal moves in the polymer metal complex, whereby a highly durable electrode active component in which the catalyst metal is stably coordinated is prepared.
  • Calcination temperature is 650 to 800 ° C, preferably 680 to 780 ° C, more preferably 690 to 760 ° C, and further preferably 700 to 750 ° C. By calcining at this temperature, a calcined metal complex as a catalyst component having high ORR catalyst activity and durability can be obtained.
  • ammonia gas can be used as the reducing gas.
  • the calcination treatment can be performed by a known method for heat-treating the electrode catalyst.
  • the powder of the polymer metal complex may be calcined in the reducing gas atmosphere at the calcining temperature for 30 minutes to 3 hours, preferably 1 hour to 2 hours.
  • the calcination metal complex is preferably pre-leached with hydrochloric acid, nitric acid or sulfuric acid solution to remove insoluble substances and inactive catalysts.
  • the target baked metal complex can be obtained by thoroughly washing with water (including deionized water and distilled water), etc., and then recovering by centrifugation or filtration, followed by drying. .
  • the obtained fired metal complex is preferably powdered using a crystal mortar or the like into fine particles.
  • the calcined metal complex obtained in this step is a catalyst component, it can be used as it is as the electrode catalyst of the present invention.
  • an electrode catalyst having the same or higher ORR catalytic activity, durability and corrosion resistance as compared with known electrode catalysts such as Pt-based catalysts and CoTMPP catalysts can be obtained at low cost and relatively easily.
  • a simple manufacturing method can be provided.
  • Gas diffusion electrode 3-1 Outline
  • the third embodiment of the present invention is a gas diffusion electrode (electrode for fuel cell).
  • fuel cell refers to a solid polymer fuel cell (PEFC) (Polymer Electrolyte Fuel Cell) and a phosphoric acid fuel cell (PAFC) (Phosphoric Fuel Acid Cell), and a microbial fuel cell.
  • PEFC Solid polymer fuel cell
  • PAFC phosphoric acid fuel cell
  • MFC Microbial Fuel Cell
  • the gas diffusion electrode of the present invention includes an electrode catalyst and a conductive carrier that supports the electrode catalyst. Moreover, a support body can also be included as needed. Hereinafter, each component will be specifically described.
  • Electrode catalyst The gas diffusion electrode of this invention contains the electrode catalyst obtained by the electrode catalyst as described in 1st Embodiment, or the manufacturing method as described in 2nd Embodiment. Since the configuration of each electrode catalyst has been described in detail in the above embodiment, a description thereof is omitted here.
  • the electrode catalyst may be at least partially disposed on the surface of the electrode so that the gas diffusion electrode of the present invention can perform ORR between the reaction gas or the electron donating microorganisms.
  • Conductive carrier refers to a substance having conductivity and capable of supporting an electrode catalyst.
  • the material is not particularly limited as long as it has the above characteristics. For example, a carbonaceous material, a conductive polymer, a semiconductor, a metal, etc. are mentioned.
  • carbon-based substance refers to a substance containing carbon (C) as a constituent component.
  • C carbon
  • graphite activated carbon
  • carbon powder including carbon black, Vulcan XC-72R, acetylene black, furnace black, Denka black
  • carbon fiber including graphite felt, carbon wool, carbon woven fabric
  • carbon plate This includes carbon paper, carbon discs, and also fine structure materials such as carbon nanotubes, carbon nanohorns and carbon nanoclusters.
  • the “conductive polymer” is a generic term for polymer compounds having conductivity.
  • a single monomer or a polymer of two or more monomers having aniline, aminophenol, diaminophenol, pyrrole, thiophene, paraphenylene, fluorene, furan, acetylene, or a derivative thereof as a structural unit can be given.
  • polyaniline, polyaminophenol, polydiaminophenol, polypyrrole, polythiophene, polyparaphenylene, polyfluorene, polyfuran, and polyacetylene are applicable.
  • a suitable conductive support is a carbon-based material, but the present invention is not limited thereto.
  • the carrier may be composed of a single species or a combination of two or more species.
  • a carrier combining a carbon-based material and a conductive polymer, or a carrier combining a carbon powder and carbon paper, which are the same carbon-based material, can be used.
  • the shape of the carrier is not particularly limited as long as the shape can support the electrode catalyst of the first embodiment on the surface.
  • a powder shape or fiber shape having a large specific surface area per unit mass is preferable.
  • the larger the specific surface area of the support the larger the support area can be secured, the dispersibility of the catalyst component on the support surface can be improved, and more catalyst components can be supported on the surface.
  • a fine particle shape such as carbon powder and a fine fiber shape such as carbon fiber are suitable as the carrier shape.
  • a fine powder having an average particle diameter of 1 nm to 1 ⁇ m is particularly preferable.
  • carbon black having an average particle size of about 10 nm to 300 ⁇ m is suitable as a carrier in this step.
  • the carrier has a connection terminal for a lead wire connecting the fuel cell electrode and an external circuit in a part thereof.
  • Support refers to a substance that itself has rigidity and can give a certain shape to the gas diffusion electrode of the present invention.
  • the conductive carrier is in a powder form or the like, it is impossible to maintain a certain shape as a gas diffusion electrode only with the conductive carrier carrying the electrode catalyst. Further, when the conductive carrier is in a thin layer state, the carrier itself does not have rigidity. In such a case, a certain shape and rigidity are imparted as an electrode by disposing a conductive carrier carrying an electrode catalyst on the surface of the support.
  • the support is not an essential component of the gas diffusion electrode of the present invention.
  • the conductive carrier itself has a certain shape and rigidity, such as a carbon disk, it is possible to maintain a certain shape as a gas diffusion electrode only by the conductive carrier carrying the electrode catalyst.
  • the electrolyte material itself may give a certain shape and rigidity to the gas diffusion electrode.
  • the support is not necessarily required. Therefore, the support may be added to the gas diffusion electrode of the present invention as necessary.
  • the material of the support is not particularly limited as long as the electrode is rigid enough to maintain a certain shape. It does not matter whether it is an insulator or a conductor. In the case of an insulator, for example, glass, plastic, synthetic rubber, ceramics, or water- or water-repellent treated paper or plant pieces (including wood pieces), animal pieces (eg bone pieces, shells, sponges) Can be mentioned.
  • An insulator for example, glass, plastic, synthetic rubber, ceramics, or water- or water-repellent treated paper or plant pieces (including wood pieces), animal pieces (eg bone pieces, shells, sponges) Can be mentioned.
  • a support having a porous structure is more preferable because the specific surface area for joining the conductive support carrying the electrode catalyst is increased and the mass activity of the electrode can be increased. Examples of the support having a porous structure include porous ceramics, porous plastics, animal pieces, and the like.
  • a carbonaceous material for example, including carbon paper, carbon fiber, and carbon rod
  • metal, conductive polymer, and the like can be given.
  • the support When the support is a conductor, it can function as a support and a current collector by disposing a conductive carrier carrying an electrode catalyst on its surface.
  • the shape of the support usually reflects the shape of the gas diffusion electrode.
  • the shape of the support is not particularly limited as long as it can serve as an electrode. What is necessary is just to determine suitably according to the shape etc. of a fuel cell. For example, (substantially) flat (including thin layer), (substantially) columnar, (substantially) spherical, or a combination thereof may be mentioned.
  • Electrocatalyst Support Method As a method for supporting the electrode catalyst on a conductive carrier, a method known in the art can be used. For example, a method of fixing the fired metal complex on the surface of the conductive support using an appropriate fixing agent can be mentioned.
  • the fixing agent is preferably conductive, but is not limited.
  • a conductive polymer solution obtained by dissolving the conductive polymer in a suitable solvent, a polytetrafluoroethylene (PTFE) dispersion, or the like can be used as the fixing agent.
  • Such a sticking agent is applied or sprayed on the surface of the conductive support and / or the surface of the electrode catalyst to mix them together, or impregnated in a solution of the sticking agent and then dried to conduct the electrocatalyst.
  • Loading on a functional carrier can be achieved.
  • Gas diffusion electrode formation method As a method for forming the gas diffusion electrode, a method known in the art can be used. For example, a conductive carrier carrying an electrode catalyst is mixed with a PTFE dispersion (for example, Nafion (registered trademark; DuPont) solution), etc., molded into an appropriate shape, and then subjected to heat treatment to form a gas diffusion electrode. Can be formed. When forming an electrode on the surface of a solid polymer electrolyte membrane or electrolyte matrix layer, such as PEFC or PAFC, the mixed solution is formed into a sheet shape, and proton conductivity is formed on the membrane bonding surface of the formed electrode sheet.
  • a PTFE dispersion for example, Nafion (registered trademark; DuPont) solution
  • a fluororesin ion-exchange membrane solution or the like having the above After applying or impregnating a fluororesin ion-exchange membrane solution or the like having the above, it may be hot-pressed on both sides of the membrane and bonded to the membrane.
  • a fluororesin ion-exchange membrane solution or the like having the above, it may be hot-pressed on both sides of the membrane and bonded to the membrane.
  • Nafion, Flemion registered trademark; Asahi Glass Co., Ltd.
  • the fluorine resin ion exchange membrane having proton conductivity can be used for the fluorine resin ion exchange membrane having proton conductivity.
  • heat treatment can be performed to form a gas diffusion electrode.
  • a mixed ink or mixed slurry of a solution of proton conductive ion exchange membrane (for example, Nafion solution) and a conductive carrier carrying an electrode catalyst is applied to the surface of a support, a solid polymer electrolyte membrane, an electrolyte matrix layer, or the like. May be formed.
  • a solution of proton conductive ion exchange membrane for example, Nafion solution
  • a conductive carrier carrying an electrode catalyst is applied to the surface of a support, a solid polymer electrolyte membrane, an electrolyte matrix layer, or the like. May be formed.
  • a gas diffusion electrode that has the same or higher catalytic activity, durability, and corrosion resistance than a Pt-based catalyst, and that can be stably supplied at a lower cost than a conventional Pt-based catalyst. Can be provided.
  • Fuel cell 4-1. Outline The fourth embodiment of the present invention is a fuel cell.
  • a fuel cell according to the present invention includes the gas diffusion electrode described in the third embodiment.
  • the fuel cell of the present embodiment can be suitably used for a hydrogen fuel cell or MFC as described above.
  • a hydrogen fuel cell is a fuel cell that obtains electrical energy from hydrogen and oxygen based on the reverse action of water electrolysis.
  • PEFC, PAFC, alkaline fuel cell (AFC), molten carbonate fuel cell (MCFC: Molten Cabonate Fuel Cell), solid oxide fuel cell (SOFC), etc. are known, but PEFC and PAFC are preferred for the fuel cell of the present invention.
  • PEFC is a proton conductive ion exchange membrane
  • PAFC is a fuel cell using phosphoric acid (H 3 PO 4 ) impregnated in a matrix layer as an electrolyte material.
  • Electron-donating microorganisms include the genus Shewanella (eg, Shewanella leuhica; S. loihica, Shewanella oneidensis; S. oneidensis, Shewanella putrefaciens; S. putrefaciens, and S. algae).
  • Pseudomonas genus eg P. aeruginosa
  • Rhodoferax genus eg Rhoferferferax ferrireducens
  • Geobacter genus eg G. sulfurreducens, G. metallireducens; G. metallireducens
  • the fuel cell of the present invention may have a known configuration in each fuel cell except that the gas diffusion electrode of the third embodiment is used as an electrode.
  • “Technology for Fuel Cell”, edited by the IEEJ Fuel Cell Power Generation Next Generation System Technology Research Special Committee, Ohm, H17, Watanabe, K., J. Biosci. Bioeng., 2008, .106: 528-536 It can have the structure described in the above.
  • the gas diffusion electrode of the third embodiment can be used for either the anode (fuel electrode) or the cathode (air electrode).
  • the electrode catalyst of the present invention included in the electrode catalyzes the reaction of H 2 ⁇ H + + 2e ⁇ of hydrogen gas as a fuel. , Donate electrons to the anode.
  • the cathode 1 / 2O 2 + 2H + + 2e of the oxygen gas as an oxidizing agent - ⁇ H 2 O to catalyze the reaction of.
  • the gas diffusion electrode of the present invention is mainly used as a cathode that causes the same electrode reaction as that of a hydrogen fuel cell.
  • Example 1 Preparation of electrode catalyst> Experimental Example 1 Preparation of Co-2,6-diaminopyridine polymer (CoDAPP) catalyst
  • CoDAPP Co-2,6-diaminopyridine polymer
  • the CoDAPP catalyst followed the method of the second embodiment of the present invention.
  • 2,6-diaminopyridine monomer (Aldrich) and oxidizing agent ammonium peroxydisulfate (APS) (Wako) were mixed at a molar ratio of 1: 1.5 and stirred. Specifically, 5.45 g of 2,6-diaminopyridine and 1 g of sodium hydroxide were dissolved in 400 mL of distilled water, and then 27.6 g of APS and 100 mL of water were added.
  • the suspension was subjected to ultrasonic mixing with sonicator ultrasonic probe systems (As One Co., Ltd.) for 1 hour and further stirred at 60 ° C. for 2 hours, and then the solution was evaporated.
  • the remaining powder of the polymer metal complex consisting of 2,6-diaminopyridine polymer and cobalt was ground in a crystal mortar.
  • the polymer metal complex was baked at 700 ° C. for 1.5 hours in an ammonia gas atmosphere.
  • the obtained calcined metal complex was subjected to ultrasonic pre-leach with a 12 N hydrochloric acid solution for 8 hours to remove insoluble substances and inactive substances, and then thoroughly washed with deionized water.
  • the calcined metal complex which is the electrode catalyst of the present invention was recovered by filtration and dried at 60 ° C.
  • Example 2 Preparation of Fe-2,6-diaminopyridine polymer (FeDAPP) catalyst Except for using iron (iron nitrate (II); Wako Pure Chemical Industries) instead of cobalt nitrate as the catalyst metal atom, The same operation as in Example 1 (Experimental Example 1) was performed.
  • iron iron nitrate (II); Wako Pure Chemical Industries
  • Example 3 Preparation of Fe / Co-2,6-diaminopyridine polymer (Fe / CoDAPP) catalyst Except that iron nitrate (III) (Wako Pure Chemical Industries) was used in addition to cobalt nitrate as the catalyst metal atom. Then, the same operation as in Example 1 (Experimental Example 1) was performed. The molar mixing ratio of cobalt nitrate and iron (III) nitrate was 1: 1, and the molar mixing ratio of PAPA / Co (NO3) 2 / Fe (NO3) 3 was 8: 1: 1.
  • CoTMPP catalyst was prepared by the method of Deng et al. (Liu Deng, Ming Zhou, Chang Liu, Ling Liu, Changyun Liu, Shaojun Dong, 2010, Talanta 81: 444-448 ). In the preparation of the CoTMPP catalyst, since it is in a mixed state with carbon that becomes a conductive carrier at the time of firing, as a result, the electrode is prepared simultaneously with the catalyst preparation. In the present specification, an electrode including such a CoTMPP catalyst is referred to as a “CoTMPP electrode”.
  • the carbon fine particle Vulcan XC-72R was sonicated in a 6M nitric acid solution for 1 hour, then treated at 100 ° C. for 6 hours, and then washed with deionized water three times. Finally, it was collected by centrifugation at 3000 rpm and dried under vacuum.
  • CoPPy Catalyst Synthesis of polypyrrole doped with 4-toluenesulfonic acid (TsOH) was performed in accordance with the method disclosed in Non-Patent Document 2.
  • the CoPPy catalyst is also mixed with carbon that becomes a conductive carrier at the time of calcination, like the CoTMPP catalyst. Therefore, an electrode including the CoPPy catalyst is referred to as a “CoPPy electrode” in this specification.
  • Vulcan XC-72R was treated in the same manner as in Comparative Example 1. Then 3 mmol of pyrrole and 100 mL of double distilled water were added and the mixture was stirred for another 30 minutes. Subsequently, 100 mL of 0.06 mol / L APS solution and 0.1902 g of 4-toluenesulfonic acid (TsOH) were added. The mixture was then stirred at room temperature for 4 hours, after which the mixture was filtered and washed alternately with double distilled water and alcohol at least three times. Finally, it was dried for 12 hours under vacuum, and the remaining powder was ground in a crystal mortar.
  • TsOH 4-toluenesulfonic acid
  • Pt catalyst purchased from Tanaka Kikinzoku Kogyo Co., Ltd. 20% Pt / C nanoparticle as an electrode by which the commercially available Pt was carry
  • an electrode including a Pt catalyst such as a Pt-supported carbon electrode is referred to as a “Pt electrode”.
  • Example 2 Catalytic activity (1)> Bipotentiostat using a rotating ring-disk electrode (RRDE) for the catalytic activity of the oxygen reduction reaction (ORR) of the catalyst included in each electrode prepared in Example 1 (excluding Experimental Example 2) Verified by Pine Instrument).
  • RRDE rotating ring-disk electrode
  • ORR oxygen reduction reaction
  • Example 2 mg each of the electrode catalyst (CoDAPP catalyst and FeDAPP catalyst) and the electrode (CoTMPP electrode, CoPPy electrode and Pt electrode) prepared in Example 1 were each 20 ⁇ L of Nafion (registered trademark) solution (5% by weight; DuDPont) and 1 mL.
  • the catalyst ink or electrode ink was prepared by mixing with ethanol and blending in an ultrasonic bath for 30 minutes and dispersing uniformly.
  • an RRDE electrode carrying each catalyst or electrode at 1 mg / cm 2 was obtained.
  • an electrode using RRDE as a conductive carrier and CoDAPP or FeDAPP as an electrode catalyst an electrode including such a CoDAPP catalyst or FeDAPP catalyst is referred to as a “CoDAPP electrode” or an “FeDAPP electrode”, respectively in this specification).
  • a CoTMPP electrode, a CoPPy electrode, and a Pt electrode using RRDE as a further conductive carrier is referred to as a “CoDAPP electrode” or an “FeDAPP electrode”, respectively in this specification.
  • a CoTMPP electrode, a CoPPy electrode, and a Pt electrode using RRDE as a further conductive carrier.
  • Electrochemical measurement of electrode The catalyst current was evaluated in oxygen-saturated 0.05M H 2 SO 4 , 0.2M K 2 H 2 PO 4 / KH 2 PO 4 and 0.1M KOH solution (pH 1). Then, measurement was performed at a potential scanning speed of 5 mV / s at room temperature and a rotation speed of 1500 rpm at room temperature.
  • n 4i D / (i D + i R / N) (1)
  • i D is the sensitive current on the disk
  • i R is the sensitive current on the ring
  • N is the collection efficiency determined by the electrode dimensions (disk outer diameter, ring outer diameter and inner diameter). In this embodiment, it is 0.19.
  • a scanning potential range of 0.8 to ⁇ 0.3 V was selected for SCE when the pH value of the RRDE electrode was equal to 1.
  • [result] 1. Mixing ratio of 2,6-diaminopyridine polymer and cobalt nitrate (molar ratio of raw material monomer and catalytic metal atom) and ORR catalytic activity at CoDAPP electrode and molar ratio of raw material monomer and cobalt with 2,6-diaminopyridine polymer and cobalt nitrate
  • the electrode catalyst CoDAPP
  • Figure 1 shows the results.
  • a, b, c, and d are 2,6-diaminopyridine polymer and a raw material monomer: cobalt molar ratio of 4: 1, 6: 1, 8: 1, and 10: 1, respectively.
  • the ORR catalytic activity of a CoDAPP electrode including a calcined metal complex CoDAPP prepared by mixing cobalt nitrate as an electrode catalyst is shown, and e shows the ORR catalytic activity of a Pt electrode.
  • the CoDAPP electrode had a larger catalyst current than the Pt electrode even when 2,6-diaminopyridine polymer and cobalt nitrate were mixed at any mixing ratio.
  • a, b, c, and d indicate a CoDAPP electrode, a CoTMPP electrode, a CoPPy electrode, and a Pt electrode, respectively.
  • the number (n) of electron transfer between ORRs calculated by the above equation (1) was 3.98 for the CoDAPP electrode, 3.91 for the CoTMPP electrode, 3.68 for the CoPPy electrode, and 3.99 for the Pt electrode. From this result, it can be seen that most of the products of the oxygen reduction reaction are H 2 O (4-electron reduction).
  • FIG. 2 demonstrates that the CoDAPP electrode is inferior to the Pt electrode in falling potential, but the falling amount is superior, so that a larger current can be obtained as an oxygen reduction catalyst.
  • Example 3 Catalytic activity (2)> The FeDAPP catalyst prepared in Experimental Example 2 of Example 1 was applied on the surface of RRDE using the same method as in Example 2, and the electrode using such RRDE as a conductive support and FeDAPP as an electrode catalyst (such as The electrode containing the FeDAPP catalyst is referred to as “FeDAPP electrode” in this specification), and the ORR catalytic activity of the FeDAPP catalyst was verified.
  • FIG. 3 shows that FeDAPP catalyst has higher falling potential and higher falling amount than CoDAPP catalyst, and therefore FeDAPP has a higher ability as a catalyst than CoDAPP.
  • Example 4 Catalytic activity (3)> Whether or not the electrode catalyst has two or more different catalytic metals coordinated with each other compared with a single catalytic metal coordinated was examined.
  • Electrode catalyst coordinating two or more different catalytic metals the Fe / CoDAPP catalyst prepared in Experimental Example 3 of Example 1 was used on the surface of RRDE using the same method as in Example 2. And an electrode using Fe / CoDAPP as an electrode catalyst (an electrode including such an Fe / CoDAPP catalyst is referred to as an “Fe / CoDAPP electrode” in this specification). Further, the CoDAPP electrode prepared in Example 2 and the FeDAPP electrode prepared in Example 3 were used as the electrode catalyst for coordinating a single catalytic metal for comparison.
  • the Fe / CoDAPP electrode had a falling potential equal to or higher than the FeDAPP electrode and CoDAPP electrode, and the amount of falling was excellent. Therefore, even an electrode catalyst that coordinates two or more different catalytic metals has oxygen reduction catalytic ability, and in particular, in the case of an electrode catalyst that coordinates Fe and Co, each coordinates independently. It was revealed that the oxygen reduction catalytic ability was higher than that of the electrode catalyst.
  • Example 5 Content ratio of carbon, nitrogen and catalyst metal in each electrode catalyst>
  • the elemental composition of the electrode catalyst prepared in Example 1 or the gas diffusion electrode containing the same was analyzed using XPS analysis, and carbon (C), nitrogen (N) and cobalt (Co ) Content ratio was examined.
  • the XPS measurement was performed using an XPS apparatus (Axis Ultra HAS; Kratos Analytical) and monochromatic Al X-rays (10 KV) as excitation X-rays. Measurements and narrow scan spectra for C, N, O and Co were performed on the CoDAPP catalyst, CoTMPP electrode and CoPPy electrode.
  • CoTMPP / C and CoPPy / C indicate a CoTMPP electrode and a CoPPy electrode using carbon fine particles as a conductive carrier, respectively.
  • the element ratio of nitrogen to carbon in the CoDAPP catalyst of the present invention after pickling treatment with hydrochloric acid (acid washing) was 0.12 in terms of molar ratio (N / C). Further, the elemental ratio of the catalytic metal (here, cobalt Co) to nitrogen was 0.06 in terms of molar ratio (Co / N). Furthermore, it was revealed that the molar ratio of nitrogen to catalyst metal (N / Co%) was 10% or more. This molar ratio is clearly higher than that of the known CoTMPP electrode and CoPPy electrode, and is more than 5 times and 1.75 times the respective molar ratio. This result shows that the 2,6-diaminopyridine polymer constituting the CoDAPP catalyst can contain a large amount of nitrogen as a ligand (coordinating atom) compared to the electrode catalyst included in other gas diffusion electrodes. Suggests.
  • Example 6 Content ratio of nitrogen and catalytic metal in CoDAPP catalyst> Calculate the amount of 2,6-diaminopyridine polymer and cobalt nitrate from the molar ratio so that the molar ratio of 2,6-diaminopyridine and cobalt is 6: 1, 8: 1, 10: 1
  • the elemental composition of the CoDAPP catalyst thus prepared was similarly analyzed using XPS analysis, and the content ratio of nitrogen (N) and cobalt (Co) was examined.
  • the CoDAPP catalyst was prepared by the method described in Experimental Example 1 of Example 1, and the polymer metal complex was calcined at 700 ° C. for 1 hour in a nitrogen gas atmosphere instead of in an ammonia gas atmosphere. What was prepared by the method similar to Example 1 was used. The analysis of the element composition was in accordance with the method described in Example 5.
  • the CoDAPP catalyst of the present invention had a molar ratio of nitrogen to carbon (N / C) ranging from 0.11 to 0.15. Further, the elemental ratio of the catalyst metal to nitrogen after the pickling treatment (acid washing) was 0.03 to 0.49 in terms of molar ratio (Co / N).
  • the electrode catalyst of the present invention has an element ratio of nitrogen to carbon of 0.1 to 0.2 in terms of molar ratio, and an element ratio of metal to nitrogen after acid cleaning of 0.03 or more in molar ratio. It was shown that there is.
  • the N / C ratio can be significantly improved to exceed 0.1. It was also revealed that high activity was obtained even when the N / C ratio was 0.1 or more, but the activity peaked out when it exceeded 0.2.
  • Example 7 Stability of catalyst activity> The loss of catalytic activity at the CoDAPP electrode was verified. [Method] Using a CoDAPP electrode, the rotation speed was 500 rpm under a scanning speed of 5 mV / s. In order to prevent the loss of catalyst between the rotation steps, the ratio of Nafion to catalyst was shifted to 1: 1.
  • Example 8 Verification of power generation capability> The power generation capacity of each gas diffusion electrode was verified by a single tank type MFC.
  • the graphite felt modified with carbon nanotubes (Japanese Patent Application No. 2010-257390) was used for the anode.
  • an Ag / AgCl electrode (Hokuto Denko) was attached as a reference electrode.
  • Electron-donating microorganism As the electron-donating microorganism, a microorganism contained in paddy soil collected in Kamaishi City, Japan was used.
  • the electrolytic cell used in the present example is a single electrolytic cell, and an electrolytic solution to which an electron donating microorganism and a nutrient substrate are added is accommodated in the electrolytic cell.
  • the specific configuration of the electrolytic cell is as follows: 12 mL of buffer solution containing 200 mM K 2 HPO 4 / KH 2 PO 4 (pH 6.8) is placed in an electrolytic cell having a capacity of 15 mL as a nutrient substrate.
  • An organic mixed substrate in which starch: peptone: fishmeal was mixed 3: 1: 1 (289 g COD / L, COD chemical oxygen demand) was used.
  • a separator paper towel was inserted between the anode and the cathode in order to prevent both electrodes from being short-circuited.
  • the anode and cathode were connected to an external circuit via a resistor (10 k ⁇ ).
  • the organic mixed substrate was added to the electrolytic cell at 0.2 to 0.4 mL per day. Subsequently, the medium was purged with nitrogen for 5 minutes. 500 mg (wet weight) of the paddy soil was added to the electrolytic cell and cultured anaerobically at 30 ° C. Thereafter, 0.2 mL of the organic mixed substrate (300 g COD / L) was added to the electrolytic cell per day. The anolyte solution was run for 2 weeks with gentle stirring at about 50 rpm, and using a potentiostat (HA-1510, Hokuto Denko), the current at various total voltages was measured and the current / current at each gas diffusion electrode was measured. A voltage (IV) curve and an output curve were obtained.
  • FIG. 5A shows a current / voltage curve of a microbial fuel cell when each gas diffusion electrode is used as a cathode
  • FIG. 5B shows an output.
  • Example 9 Activity evaluation of cathode in microbial fuel cell> [Method] A reference electrode is inserted into the MFC of Example 7 to determine whether the increase in power generation capacity in the fuel cell is due to an increase in cathode activity, and the anode and cathode currents are arbitrarily set with a potentiostat with respect to the reference electrode during power generation. While measuring.
  • FIG. This figure shows the anode and cathode polarization curves of the fuel cell measured using an Ag / AgCl electrode as a reference electrode.
  • Curves indicated by black plots (a) to (d) are anode polarization curves
  • curves indicated by white plots (a ′) to (d ′) are cathode polarization curves.
  • a comparison of the cathodic polarization curves shows that a large current was obtained at the highest potential using the CoDAPP electrode.
  • the efficiency of the anode was improved because the electrode consumed the electrons efficiently.
  • Example 10 Cyclic voltammogram when each electrode is used as a cathode> Cyclic voltammograms were measured by MFC using each electrocatalyst in Example 7 as a cathode, and electron transfer characteristics in the presence of a mixture of microorganisms were examined.
  • the cyclic voltammogram is a measurement of the current flowing in the electrochemical cell by continuously changing the potential of the working electrode with respect to the reference electrode. The redox potential of this reaction system is obtained from the midpoint of the + and-peaks at that time.
  • FIG. A is a cyclic voltammogram when a CoDAPP electrode is used
  • B is a Pt electrode
  • C is a CoTMPP electrode as a cathode.
  • the solid line is the measurement result in the presence of oxygen
  • the broken line is the measurement result in the absence of oxygen.
  • Example 11 Conductivity of electrode catalyst> [Method]
  • the CoDAPP catalyst powder prepared by the method described in Experimental Example 1 of Example 1 was compacted into cylindrical pellets having a diameter of 10 mm and a thickness of 2 mm using a die. The compacting was performed at a pressure of 10 MPa for 30 seconds.
  • the conductivity of the prepared pellets was measured using a Loresta-EP low resistivity meter (Mitsubishi Chemical) and a four-probe probe (PSP probe, Mitsubishi Chemical).
  • the conductivity was a normal distribution centered around 5 S / cm and was in the range of 0.1 S / cm to 10 S / cm.
  • Example 11 Specific surface area of electrode catalyst> [Method] The specific surface area was measured by a nitrogen BET adsorption method. Specifically, first, the CoDAPP catalyst prepared by the method described in Example 1 and a 20% Pt / C catalyst (manufactured by Tanaka Kikinzoku) as a reference were heated at 200 ° C. for 1 hour at 10 ⁇ 3 Pa and vacuum dried. Then, moisture and adsorbate in the sample were removed. For each of the above-treated catalysts, an isotherm adsorption line was measured using Autosorb-3 (manufactured by Quantachrome), and linear conversion was performed by the BET method to calculate a specific surface area.
  • Autosorb-3 manufactured by Quantachrome
  • FIG. A is an isothermal adsorption line when a CoDAPP catalyst is used and B is a 20% Pt / C catalyst used as a cathode.
  • the specific surface area of the CoDAPP catalyst was 568 m 2 / g.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Materials Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Microbiology (AREA)
  • Biochemistry (AREA)
  • Sustainable Development (AREA)
  • Sustainable Energy (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Inert Electrodes (AREA)
  • Fuel Cell (AREA)
  • Catalysts (AREA)

Abstract

La présente invention vise à développer et proposer un catalyseur d'électrode ayant une activité catalytique dans des réactions de réduction d'oxygène qui est comparable ou plus grande que celle de catalyseurs à base de Pt, ainsi qu'une durabilité et une résistance à la corrosion, et que l'on peut fournir de façon bon marché et constante ; ainsi qu'une électrode de pile à combustible utilisant le catalyseur d'électrode et une pile à combustible comportant l'électrode. A cet effet, sont proposés un catalyseur d'électrode qui inclut comme composant catalyseur un complexe métallique calciné obtenu par calcination d'un complexe polymère-métal comprenant un polymère diaminopyridine et un métal catalyseur, une électrode de pile à combustible l'utilisant et une pile à combustible comportant l'électrode.
PCT/JP2012/061722 2011-05-24 2012-05-08 Catalyseur d'électrode et procédé de production de celui-ci WO2012160957A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP2011116146 2011-05-24
JP2011-116146 2011-05-24
JP2011-275678 2011-12-16
JP2011275678 2011-12-16

Publications (1)

Publication Number Publication Date
WO2012160957A1 true WO2012160957A1 (fr) 2012-11-29

Family

ID=47217040

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2012/061722 WO2012160957A1 (fr) 2011-05-24 2012-05-08 Catalyseur d'électrode et procédé de production de celui-ci

Country Status (1)

Country Link
WO (1) WO2012160957A1 (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015045217A1 (fr) * 2013-09-24 2015-04-02 パナソニック株式会社 Matériau contenant du carbone, électrode, pile à combustible et procédé de production de matériau contenant du carbone
WO2015049318A1 (fr) * 2013-10-01 2015-04-09 Imperial Innovations Limited Catalyseurs de réduction d'oxygène
JP2016038988A (ja) * 2014-08-06 2016-03-22 東洋インキＳｃホールディングス株式会社 微生物燃料電池用炭素触媒及びその製造方法、触媒インキ並びに微生物燃料電池
CN110343247A (zh) * 2019-06-20 2019-10-18 西南民族大学 一种过氧化物拟酶用高分子纳米材料及其制备方法
CN110504459A (zh) * 2019-07-30 2019-11-26 东华大学 一种硫化钴/氮掺杂介孔碳材料及其制备方法与应用
CN111584883A (zh) * 2020-05-11 2020-08-25 苏州大学 一种自支撑氧还原催化剂及其制备方法、应用

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005066592A (ja) * 2003-08-05 2005-03-17 Toyota Motor Corp 触媒材料およびその製造方法
WO2006083029A1 (fr) * 2005-02-03 2006-08-10 Toyota Jidosha Kabushiki Kaisha Materiau catalytique et procede pour sa preparation
JP2007136283A (ja) * 2005-11-15 2007-06-07 Toyota Central Res & Dev Lab Inc 含窒素炭素系電極触媒
JP2007529865A (ja) * 2004-03-15 2007-10-25 セント・ルイス・ユニバーシティ 微小流体バイオ燃料電池
JP2008222486A (ja) * 2007-03-12 2008-09-25 Osaka City 金属含有炭化物およびその製造方法
WO2009025176A1 (fr) * 2007-08-23 2009-02-26 Nec Corporation Catalyseur pour une électrode de réduction d'oxygène, et électrode de réduction d'oxygène

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005066592A (ja) * 2003-08-05 2005-03-17 Toyota Motor Corp 触媒材料およびその製造方法
JP2007529865A (ja) * 2004-03-15 2007-10-25 セント・ルイス・ユニバーシティ 微小流体バイオ燃料電池
WO2006083029A1 (fr) * 2005-02-03 2006-08-10 Toyota Jidosha Kabushiki Kaisha Materiau catalytique et procede pour sa preparation
JP2007136283A (ja) * 2005-11-15 2007-06-07 Toyota Central Res & Dev Lab Inc 含窒素炭素系電極触媒
JP2008222486A (ja) * 2007-03-12 2008-09-25 Osaka City 金属含有炭化物およびその製造方法
WO2009025176A1 (fr) * 2007-08-23 2009-02-26 Nec Corporation Catalyseur pour une électrode de réduction d'oxygène, et électrode de réduction d'oxygène

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015045217A1 (fr) * 2013-09-24 2015-04-02 パナソニック株式会社 Matériau contenant du carbone, électrode, pile à combustible et procédé de production de matériau contenant du carbone
WO2015049318A1 (fr) * 2013-10-01 2015-04-09 Imperial Innovations Limited Catalyseurs de réduction d'oxygène
JP2016038988A (ja) * 2014-08-06 2016-03-22 東洋インキＳｃホールディングス株式会社 微生物燃料電池用炭素触媒及びその製造方法、触媒インキ並びに微生物燃料電池
CN110343247A (zh) * 2019-06-20 2019-10-18 西南民族大学 一种过氧化物拟酶用高分子纳米材料及其制备方法
CN110343247B (zh) * 2019-06-20 2022-01-04 西南民族大学 一种过氧化物拟酶用高分子纳米材料及其制备方法
CN110504459A (zh) * 2019-07-30 2019-11-26 东华大学 一种硫化钴/氮掺杂介孔碳材料及其制备方法与应用
CN110504459B (zh) * 2019-07-30 2022-10-11 东华大学 一种硫化钴/氮掺杂介孔碳材料及其制备方法与应用
CN111584883A (zh) * 2020-05-11 2020-08-25 苏州大学 一种自支撑氧还原催化剂及其制备方法、应用

Similar Documents

Publication Publication Date Title
Zhao et al. Efficient bifunctional Fe/C/N electrocatalysts for oxygen reduction and evolution reaction
Choi et al. Highly active porous carbon-supported nonprecious metal− N electrocatalyst for oxygen reduction reaction in PEM fuel cells
Khilari et al. Manganese cobaltite/polypyrrole nanocomposite-based air-cathode for sustainable power generation in the single-chambered microbial fuel cells
US9882223B2 (en) Catalysts and electrodes for fuel cells
Gharibi et al. Investigation of carbon monoxide tolerance of platinum nanoparticles in the presence of optimum ratio of doped polyaniline with para toluene sulfonic acid and their utilization in a real passive direct methanol fuel cell
US9331341B2 (en) Durable platinum/multi-walled carbon nanotube catalysts
Samanta et al. Catalyst support in oxygen electrocatalysis: a case study with CoFe alloy electrocatalyst
Anandhababu et al. Highly exposed Fe–N 4 active sites in porous poly-iron-phthalocyanine based oxygen reduction electrocatalyst with ultrahigh performance for air cathode
JP5863645B2 (ja) 直接型燃料電池のカソード用炭素触媒並びにこれを用いた直接型燃料電池用カソード及び直接型燃料電池
WO2012160957A1 (fr) Catalyseur d'électrode et procédé de production de celui-ci
CN106571474B (zh) 铂镍合金纳米团簇的制备方法及采用其的燃料电池
Ge et al. Electrocatalytic activity of cobalt phosphide-modified graphite felt toward VO2+/VO2+ redox reaction
Tintula et al. A solid-polymer-electrolyte direct methanol fuel cell (DMFC) with Pt-Ru nanoparticles supported onto poly (3, 4-ethylenedioxythiophene) and polystyrene sulphonic acid polymer composite as anode
JP2011230099A (ja) 炭素触媒及び炭素触媒の製造方法
Duan et al. Surface Engineering Route to Non-pyrolysis MOFs with High-Density Co–N x Sites and 3D Conductive Networks for Efficient Oxygen Reduction
JP5706595B1 (ja) 酸素還元触媒、その用途およびその製造方法
KR102210320B1 (ko) 전하 이동 유기 착물 기반의 orr을 위한 비-pgm 촉매
JP2006236778A (ja) 燃料電池用触媒、膜電極複合体、および固体高分子電解質型燃料電池
JP2008189837A (ja) 導電性重合体金属錯体及びそれを用いた酸化還元触媒電極
JP5114657B2 (ja) 導電性重合体金属錯体の製造方法およびそれを用いた電極触媒
Zhou et al. Single-Atom Cobalt Supported on NCNTs as Bifunctional Electrocatalysts Synthesized by Microwave-Assisted Treatment for Zn-Air Batteries
JP6921485B2 (ja) 電池カソード、電池カソード触媒層用組成物及び電池
Yang et al. Synthesis of high-performance low-Pt (1 1 1)-loading catalysts for ORR by interaction between solution and nonthermal plasma
Sakthivel et al. Low content of Ni‐Pt nanoparticles decorated carbon nanofibers as efficient electrocatalyst for hydrogen evolution reaction
JP2019029304A (ja) 電極触媒

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 12790340

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 12790340

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: JP