WO2017208742A1 - Carbon for supporting catalyst and production process therefor - Google Patents

Carbon for supporting catalyst and production process therefor Download PDF

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Publication number
WO2017208742A1
WO2017208742A1 PCT/JP2017/017460 JP2017017460W WO2017208742A1 WO 2017208742 A1 WO2017208742 A1 WO 2017208742A1 JP 2017017460 W JP2017017460 W JP 2017017460W WO 2017208742 A1 WO2017208742 A1 WO 2017208742A1
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carbon
catalyst
supporting
supporting carbon
heat treatment
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PCT/JP2017/017460
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French (fr)
Japanese (ja)
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真衣子 菊地
洋一郎 河野
博明 安藤
昌裕 佐藤
翔太 五十嵐
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ライオン・スペシャリティ・ケミカルズ株式会社
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J21/00—Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
    • B01J21/18—Carbon
    • B01J35/60—
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/08—Heat treatment
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/12—Oxidising
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/20—Graphite
    • C01B32/205—Preparation
    • 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
    • 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
    • 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 a catalyst-supporting carbon and a method for producing the same.
  • This application claims priority on May 31, 2016 based on Japanese Patent Application No. 2016-108542 for which it applied to Japan, and uses the content here.
  • catalyst-carrying carbon that carries catalytic metal particles such as platinum.
  • the catalyst-supporting carbon is required to have a high specific surface area for improving the dispersibility and reaction efficiency of the catalyst metal particles, and to improve the resistance to oxidative decomposition in a high-load oxidation potential environment such as a fuel cell.
  • the following has been proposed as catalyst-supporting carbon.
  • Patent Document 1 High surface area graphitized carbon obtained by heat treating carbon black to graphitize and then increasing the surface by vapor etching (Patent Document 1).
  • Patent Document 2 a specific surface area of 200 ⁇ 1000 m 2 / g, the peak intensity ratio of D band of the Raman spectra (1350 cm -1) and G band (1580 cm -1) 0.3 to 0.7, the X-ray diffraction method ( 002) Modified graphite having a crystallite size Lc (002) in the c-axis direction of 30 nm or more (Patent Document 2).
  • Carbon black having a specific surface area of 300 to 1100 m 2 / g, a crystal layer thickness (Lc) of 25 to 100 mm, and a maximum diameter of aggregated particles of 20 ⁇ m or less (Patent Document 3).
  • Acetylene black having a specific surface area of 500 to 1100 m 2 / g and aggregated particles of 20 ⁇ m or more of 10 ppm or less (Patent Document 4).
  • catalyst-supporting carbons such as (1) to (4), it is difficult to make both catalyst metal particles finely distributed uniformly in the carbon (dispersion supportability) and excellent oxidative decomposition resistance. .
  • An object of the present invention is to provide a catalyst-supporting carbon that has both excellent dispersion supportability of catalyst metal particles and excellent oxidative decomposition resistance, and a method for producing the catalyst-supporting carbon.
  • the present invention has the following configuration.
  • a catalyst-supporting carbon that satisfies the following conditions (a) to (d).
  • (A) The crystallite thickness Lc (002) of the carbon surface calculated from the measurement result by the wide-angle X-ray diffraction method is 2.0 nm or more.
  • C It has pores including mesopores, and the mesopore volume is 0.35 to 1.3 cm 3 / g.
  • a method for producing a catalyst-supporting carbon as described in [1] above, wherein a heat treatment step of obtaining a carbon material by heat-treating carbon black at 2200 ° C. or higher, and a carbon material after the heat treatment step A method for producing catalyst-supporting carbon, comprising: a surface oxidation step for performing a surface oxidation treatment.
  • both excellent dispersion supportability of catalyst metal particles and excellent resistance to oxidative decomposition are achieved.
  • a catalyst-supporting carbon having both excellent dispersion supportability of catalyst metal particles and excellent oxidative decomposition resistance can be obtained.
  • the catalyst-supporting carbon of the present invention satisfies the conditions (a) to (d).
  • C It has pores including mesopores, and the mesopore volume is 0.35 to 1.3 cm 3 / g.
  • the crystallite thickness Lc (002) on the carbon surface calculated from the measurement result of the catalyst-supporting carbon of the present invention by the wide-angle X-ray diffraction method is 2.0 nm or more, and preferably 3.5 to 4.5 nm. If thickness Lc (002) is more than a lower limit, it will be excellent in oxidative degradation tolerance (durability). If thickness Lc (002) is below an upper limit, it will be excellent in the reactivity in the surface oxidation process which is a post process.
  • the ratio D / G of the peak area of D 1 -band to the peak area of G-band of the spectrum of the carbon surface by Raman spectroscopy of the catalyst-supporting carbon of the present invention (1590cm -1) (1350cm -1) is 0. 5 to 2.5, preferably 0.85 to 2.5. If the ratio D / G is equal to or greater than the lower limit, the crystal structure deficiency on the carbon surface is sufficiently increased, and the catalyst is excellent in dispersion support. If the ratio D / G is equal to or less than the upper limit value, it is possible to suppress the oxidative decomposition resistance of the catalyst-supporting carbon from being excessively lost.
  • the catalyst-supporting carbon of the present invention has pores including mesopores.
  • the mesopore means a pore having a pore diameter of 2 nm or more and 50 nm or less.
  • Mesopore volume of the catalyst-supporting carbon of the present invention is 0.35 ⁇ 1.3cm 3 / g, preferably 0.5 ⁇ 1.0cm 3 / g.
  • the mesopore volume is at least the lower limit value, the catalyst is excellent in dispersion support and sufficient catalytic activity is obtained. If the mesopore volume is less than or equal to the upper limit value, it is possible to suppress the oxidative degradation resistance of the catalyst-supporting carbon due to excessive pores.
  • the mesopore volume means the total volume of all mesopores possessed by the catalyst-supporting carbon.
  • the ratio of the mesopore volume to the total pore volume of the catalyst-supporting carbon of the present invention is 0.6 or more, and preferably 0.8 or more. If the ratio of the catalyst supporting carbon is equal to or higher than the lower limit value, the catalyst is excellent in dispersion supporting property and sufficient catalytic activity can be obtained.
  • BET specific surface area of the catalyst-supporting carbon of the present invention is preferably 130 ⁇ 700m 2 / g, more preferably 200 ⁇ 600m 2 / g. If the BET specific surface area of the catalyst supporting carbon is not less than the lower limit value, the catalyst is excellent in dispersion supporting property and sufficient catalytic activity can be obtained. If the BET specific surface area of the catalyst-supporting carbon is not more than the upper limit value, the oxidative decomposition resistance of the catalyst-supporting carbon is maintained even if the treatment is performed in the subsequent surface oxidation step. The BET specific surface area of the catalyst-supporting carbon is measured under conditions based on ASTM D 3037.
  • DBP oil absorption amount of the catalyst-supporting carbon of the present invention is preferably 150 ⁇ 500cm 3 / 100g, more preferably 200 ⁇ 450cm 3 / 100g.
  • the conductivity is excellent.
  • the DBP oil absorption amount of the catalyst-supporting carbon is not more than the upper limit value, it is possible to suppress the advanced development of the aggregate and maintain good dispersibility of the catalyst-supporting carbon in the solvent at the time of preparing the catalyst ink.
  • the DBP oil absorption amount of the catalyst-supporting carbon is measured with a sample amount of 9 g under the condition based on ASTM D 2414.
  • the catalyst-supporting carbon of the present invention is a powder composed of aggregates (secondary particles) composed of a chain of primary particles.
  • the aggregate diameter (mode diameter) of the catalyst-supporting carbon of the present invention is preferably 1.0 to 35.0 ⁇ m, and more preferably 5.0 to 30.0 ⁇ m. If the aggregate diameter of the catalyst-supporting carbon is equal to or greater than the lower limit value, the metal particles are easily supported uniformly when preparing the catalyst ink. In addition, the conductivity of the catalyst-supporting carbon is excellent. If the aggregate diameter of the catalyst-supporting carbon is not more than the upper limit value, the dispersibility of the catalyst-supporting carbon in the solvent during preparation of the catalyst ink is excellent.
  • the aggregate diameter (mode diameter) is measured by the aggregate diameter measuring method described in JIS K6217-6.
  • the total mass ratio of the aggregate diameter of 20 ⁇ m or more with respect to the total mass of the catalyst-supporting carbon of the present invention is preferably 20 to 45% by mass, and more preferably 25 to 40% by mass.
  • the aggregate diameter is 20 ⁇ m or more, the conductivity is excellent.
  • the ratio of the aggregate diameter of 20 ⁇ m or more is equal to or less than the upper limit value, the dispersibility of the catalyst-supporting carbon with respect to the solvent during preparation of the catalyst ink is excellent.
  • the catalyst-supporting carbon of the present invention can be suitably used for fuel cell applications.
  • the catalyst metal particles supported on the catalyst-supporting carbon include platinum, an alloy with platinum (an alloy with platinum selected from at least one selected from nickel, cobalt, palladium, and ruthenium). Platinum is preferred for applications.
  • the supporting rate of the catalyst metal particles is not particularly limited, and can be, for example, 20 to 50% by mass based on the total mass of the catalyst-supporting carbon in which the catalyst-supporting carbon is supported on the catalyst-supporting carbon.
  • the method for producing catalyst-supporting carbon of the present invention is a method for producing the catalyst-supporting carbon of the present invention described above.
  • the method for producing catalyst-supporting carbon of the present invention includes the following heat treatment step and surface oxidation step.
  • Heat treatment process Carbon black is heat-treated at 2200 ° C. or higher to obtain a carbon material.
  • Surface oxidation process A surface oxidation process is performed on the carbon material after the heat treatment process.
  • heat treatment process carbon black is heat-treated at 2200 ° C. or higher to obtain a carbon material.
  • the heat treatment temperature is 2200 ° C. or higher, preferably 2200 to 3500 ° C., more preferably 2200 to 3000 ° C.
  • the heat treatment temperature is equal to or higher than the lower limit, the carbon black is sufficiently crystallized, and catalyst-supporting carbon that satisfies the condition (a) is obtained. If heat processing temperature is below an upper limit, it will be excellent in the reactivity in the surface oxidation process which is a post process.
  • the heat treatment time may be appropriately set according to the heat treatment temperature, and may be, for example, 1 to 30 hours.
  • ketjen black is preferable because it is easy to obtain catalyst-supporting carbon that satisfies the conditions (a) to (d). Carbon black other than ketjen black may be used.
  • BET specific surface area of the carbon black is preferably 50 ⁇ 2000m 2 / g, more preferably 100 ⁇ 1500m 2 / g, more preferably 700 ⁇ 1500m 2 / g. If the BET specific surface area of the carbon black is within the above range, it is easy to obtain catalyst-supporting carbon that satisfies the conditions (a) to (d). In addition, the BET specific surface area of carbon black is measured on the conditions based on ASTM D3037.
  • DBP oil absorption of carbon black is preferably 200 ⁇ 600cm 3 / 100g, more preferably 250 ⁇ 500cm 3 / 100g. If the DBP oil absorption of carbon black is not less than the lower limit value, the conductivity is excellent. If the DBP oil absorption of carbon black is less than or equal to the upper limit value, the advanced development of aggregates can be suppressed, and good dispersibility of the catalyst-supporting carbon in the solvent can be maintained when preparing the catalyst ink. Note that the DBP oil absorption of carbon black is a value measured with a sample amount of 9 g under conditions based on ASTM D 2414.
  • Carbon black is a powder composed of secondary particles composed of a chain of primary particles connected in a kitchen shape.
  • the average primary particle size of carbon black is preferably 5 to 100 nm, more preferably 20 to 60 nm. If the average primary particle diameter of the carbon black is within the above range, the specific surface area of the catalyst-supporting carbon increases, and the active point when supporting the catalyst metal particles increases.
  • the average primary particle diameter of carbon black is a value obtained by measuring 1000 or more particle diameters randomly in an image observed with a transmission electron microscope.
  • the aggregate diameter (mode diameter) of carbon black is preferably 1.0 to 35.0 ⁇ m, more preferably 5.0 to 30.0 ⁇ m. If the mode diameter of the carbon black is within the above range, the catalyst-supporting carbon is excellent in dispersibility in the solvent at the time of catalyst ink preparation, and the catalyst metal particles are easily supported uniformly.
  • the volatile content of carbon black is preferably 5% by mass or less, and more preferably 2% by mass or less. If the volatile content of carbon black is less than or equal to the upper limit value, the type of functional group can be suppressed in the surface oxidation treatment as a post process.
  • the volatile content of carbon black is measured by a method based on ASTM D 1620-60.
  • the magnetic crucible (diameter 15 mm, height 30 mm, capacity 10 mL) and the drop lid were baked at 950 ⁇ 20 ° C. for 30 minutes, then cooled to room temperature (25 ° C.) in a desiccator, and the mass of the magnetic crucible and drop lid ( Weigh accurately M A ) to the nearest 0.1 mg.
  • the carbon black 2g capped off by Oshitsume to the extent not exceeding the lid under 2mm in a porcelain crucible, accurately weighed its mass (M B) to 0.1mg units.
  • the magnetic crucible is then heated in an electric furnace at 950 ⁇ 20 ° C.
  • Volatile content (mass%) (M B ⁇ M C ) / (M B ⁇ M A )
  • the ash content of carbon black is preferably 0.5% by mass or less, and more preferably 0.2% by mass or less. If the ash content of carbon black is less than or equal to the upper limit value, the impurities are small and the conductivity is excellent.
  • the ash content of carbon black is measured by a method based on ASTM D 1506.
  • ketjen black having a BET specific surface area of 700 to 1500 m 2 / g is particularly preferable because a catalyst-supporting carbon satisfying the conditions (a) to (d) can be easily obtained.
  • the surface oxidation treatment method is not particularly limited, and examples thereof include a method of bringing a carbon material into contact with an aqueous solution containing an oxidizing agent.
  • the aqueous solution containing an oxidizing agent when contacting the carbon material may be in a liquid state, a subcritical state, or a supercritical state.
  • the treatment time can be appropriately determined according to the treatment method, the type of oxidizing agent, and the like.
  • the treatment time when an aqueous solution containing an oxidizing agent is in a liquid state can be 1 to 30 hours.
  • the treatment time can be 0.5 hours or longer.
  • the amount of the oxidizing agent can be 2 to 20% by mass with respect to the total mass of the aqueous solution containing the oxidizing agent.
  • the oxidizing agent is not particularly limited, and examples thereof include hydrogen peroxide, ammonium persulfate, sodium persulfate, nitric acid, hydrochloric acid, sulfuric acid and the like. Of these, hydrogen peroxide, ammonium persulfate, and sodium persulfate are preferable.
  • 1 type may be used independently and 2 or more types may be used together.
  • the catalyst-supporting carbon of the present invention described above satisfies the conditions (a) to (d), and therefore has excellent catalyst dispersibility and resistance to oxidative decomposition.
  • Catalyst loading method As a method of supporting the catalyst metal particles on the catalyst-supporting carbon of the present invention, a known method can be used. For example, a method of performing a heat treatment in an inert gas atmosphere or a heat treatment in a reducing atmosphere after adding a catalyst-supporting carbon in a solvent containing a metal complex and adsorbing the metal complex on the carbon surface. . Also, a method of adhering metal colloidal particles to the surface of a carbon by adding a catalyst-supporting carbon to a metal colloidal particle by mixing a reducing agent such as an organic acid, alcohol or ethylene glycol in a solvent containing a metal complex.
  • a reducing agent such as an organic acid, alcohol or ethylene glycol
  • a precipitation method may be used in which a catalyst is added to a solvent containing a metal complex and then a reducing agent is added to form metal colloid particles on the carbon surface.
  • the catalyst-supporting carbon may be subjected to a hydrophilization treatment or a hydrophobization treatment in advance before the catalyst metal particles are supported, and after the catalyst metal particles are supported on the catalyst-supporting carbon, a heat treatment or an acid treatment is performed. Also good.
  • A-2 product name "EC300J” (Ketjenblack, BET specific surface area: 800 m 2 / g, DBP oil absorption: 365cm 3 / 100g, volatile matter: 0.4 wt%, ash content: 0.02 wt%, average Primary particle size: 40 nm, manufactured by Lion Specialty Chemicals).
  • A-3 Product name “Denka Black 50% Press” (acetylene black, BET specific surface area: 65 m 2 / g, average primary particle size: 36 nm, ash content: 0.01% by mass, manufactured by DENKA CORPORATION).
  • the volatile content and ash content were measured as follows. [Measurement method of volatile matter] It was measured by a method according to ASTM D 1620-60. The magnetic crucible (diameter 15 mm, height 30 mm, capacity 10 mL) and the drop lid were baked at 950 ⁇ 20 ° C. for 30 minutes, then cooled to room temperature (25 ° C.) in a desiccator, and the mass of the magnetic crucible and drop lid ( M A ) was accurately weighed to the nearest 0.1 mg. Next, 2 g of carbon black was pressed into a magnetic crucible so as not to exceed 2 mm below the lid, and the lid was dropped, and the mass (M B ) was accurately weighed to the nearest 0.1 mg.
  • Example 1 Heat treatment process: Carbon black (A-1) was introduced into a firing furnace, heat-treated at 2800 ° C. for 12 hours, and then allowed to cool to room temperature to obtain a carbon material.
  • Surface oxidation process 1 g of the carbon material obtained in the heat treatment step and about 100 mL of 5% hydrogen peroxide water were put into a high pressure resistant container. The temperature was increased by covering the high pressure resistant container, and when the temperature reached 350 ° C., the pressure inside the container was increased to 25 MPa while additionally introducing 5% hydrogen peroxide water at 1.8 mL / min for 150 minutes. . After maintaining at 350 ° C.
  • the high pressure resistant container was allowed to cool, and after confirming that the inside of the container was at normal temperature and normal pressure, the container was opened and the carbon material dispersion was taken out. Next, the dispersion was filtered, and the filtered carbon material was dried under reduced pressure (1 mmHg or less) at 110 ° C. for 24 hours to obtain powdery catalyst-supporting carbon.
  • Example 2 Heat treatment process: A carbon material was obtained in the same manner as in Example 1.
  • Example 3 Except for changing the heat treatment temperature to 2200 ° C., the same heat treatment step as in Example 1 was performed to obtain a carbon material. Next, the same surface oxidation step as in Example 2 was performed to obtain powdery catalyst-supporting carbon.
  • Example 4 Except for changing the heat treatment temperature to 2200 ° C., the same heat treatment step as in Example 1 was performed to obtain a carbon material. Next, the same surface oxidation step as in Example 1 was performed to obtain powdery catalyst-supporting carbon.
  • Example 5 A carbon material was obtained by carrying out the same heat treatment step as in Example 1 except that carbon black (A-2) was used. Next, the same surface oxidation step as in Example 2 was performed to obtain powdery catalyst-supporting carbon.
  • Example 6 Except for changing the heat treatment temperature to 2500 ° C., the same heat treatment step as in Example 1 was performed to obtain a carbon material. Next, the same surface oxidation step as in Example 2 was performed to obtain powdery catalyst-supporting carbon.
  • Example 7 Using carbon black (A-3), the same surface oxidation step as in Example 2 was performed to obtain powdery catalyst-supporting carbon.
  • Example 1 Except for using carbon black (A-2), the same heat treatment step as in Example 1 was performed to obtain a carbon material, which was used as catalyst-supporting carbon.
  • Example 3 A carbon material was obtained by carrying out the same heat treatment step as in Example 1 except that carbon black (A-2) was used. 1 g of the carbon material obtained in the heat treatment step was dispersed in 200 mL of concentrated nitric acid, subjected to ultrasonic treatment (23 MHz) at room temperature for 6 hours, and then stirred at room temperature for 96 hours. After completion of the stirring, the dispersion was filtered, and the carbon material was washed with ultrapure water until the filtrate reached pH 7. The washed carbon material was dried under reduced pressure at 110 ° C. to obtain powdery catalyst-supporting carbon.
  • Crystalline thickness Lc (002) of carbon surface (thickness in thickness direction) The crystallite thickness Lc (002) of the carbon on the catalyst-supporting carbon was determined by a wide-angle X-ray diffraction method. Specifically, the catalyst-supporting carbon was measured using an X-ray diffractometer (Spectris Co., Ltd.), and a diffraction line peak on the 002 plane was obtained. The diffraction angle and half-value width of this 002 diffraction line were substituted into the following Serrer equation to calculate the crystallite thickness Lc (002) (thickness in the thickness direction) (nm) on the carbon surface.
  • Lc ⁇ / ⁇ cos ⁇
  • ⁇ is the wavelength (nm) of X-rays
  • ⁇ is the half width (nm) of the 002 diffraction line
  • ⁇ is the 002 diffraction line. Is the diffraction angle (°).
  • the BET specific surface area of the catalyst-supporting carbon was measured under conditions based on ASTM D 3037.
  • Carbon reduction amount was measured when the catalyst-carrying carbon was heated in a nitrogen atmosphere. About 20 mg of carbon was heated to 950 ° C. at 10 ° C./min by TG-DTA2000SA (Netch Japan Co., Ltd. (formerly Bruker AXS Co., Ltd.)), and the amount (%) of carbon reduction at that time was measured.
  • the platinum particle size is calculated from the half-value width of the peak of the Pt (111) plane in the spectrum obtained by the X-ray diffraction method, using the Scherrer equation. did.
  • the platinum loading rate is determined when TG-DTA2000SA (manufactured by Netch Japan Co., Ltd. (former Bruker AXS Co., Ltd.)) raises the temperature of platinum-supported carbon to 950 ° C. at a heating rate of 10 ° C./min. Calculated from the amount of platinum remaining.
  • Electrochemical surface area The electrochemical effective surface area (ECSA) of the catalyst-supporting carbon was measured according to a protocol published by the Council for Promotion of Commercialization of Fuel Cells (FCCJ).
  • the glass cell was filled with perchloric acid adjusted to 0.1 M, and nitrogen was bubbled into the glass cell for 30 minutes while heating to 60 ° C.
  • ECSA initial value
  • ECSA maintenance rate index of durability and electrode life
  • the ECSA retention rate was measured under the optimized conditions so as to further promote the deterioration phenomenon of carbon with reference to “potential cycle test method” described in the protocol published by FCCJ.
  • the glass cell was filled with perchloric acid adjusted at 0.1 M, and nitrogen was bubbled into the glass cell for 30 minutes while heating to 60 ° C.
  • CV was performed under the conditions of 0.05 to 1.20 V vs. RHE, 50 mV / s with the number of revolutions of the electrode being zero for cleaning the carbon surface and measuring ECSA.
  • ECSA maintenance rate (%) (ECSA / ECSA (initial value) after high potential load) ⁇ 100 The durability was determined according to the following criteria. ⁇ Criteria> A: ECSA maintenance rate is 70% or more. A: ECSA maintenance rate is 50% or more and less than 70%. X: ECSA maintenance rate is less than 50%.
  • Table 2 shows the measurement results and evaluation results of the physical properties of the catalyst-supporting carbon in each example.
  • the catalyst-supporting carbons of Examples 1 to 7 satisfying the conditions (a) to (d) have a high ESCA (initial value), a high platinum support rate, and excellent catalyst dispersion support. It was. Further, the catalyst-supporting carbons of Examples 1 to 7 had a high ESCA maintenance rate and excellent durability (oxidative decomposition resistance).
  • Comparative Example 1 that did not satisfy the conditions (b) and (c)
  • the ESCA (initial value) was remarkably low, the platinum support rate was low, and the dispersion support property of the catalyst was inferior.
  • Comparative Example 2 that did not satisfy the condition (a) the ESCA maintenance rate was zero, and the durability (oxidative degradation resistance) was remarkably inferior.
  • Comparative Example 3 that did not satisfy the condition (d) ESCA (initial value) was remarkably low.
  • Example 8 Preparation of platinum-supported carbon: The catalyst-supporting carbon 0.5g of Example 1, 240 g of water, and 320 g of ethylene glycol were mixed by ultrasonic waves, and then added to a mixed solution of 1.32 g of hexachloride platinum (IV) acid hexahydrate and 40 g of ethylene glycol. A 1 mol / L sodium hydroxide aqueous solution was added to adjust the pH to 11. This solution was transferred to a flask, and purged with nitrogen, followed by stirring at 110 ° C. for 4 hours. After cooling, the solution was filtered, and the filtrate was washed with pure water until pH 7 and dried under reduced pressure overnight to obtain platinum-supported carbon.
  • MEA membrane electrode assembly
  • This catalyst ink was applied to a polytetrafluoroethylene (PTFE) sheet so that the amount of catalyst was 0.3 mg / cm 2 , dried, and cut into a rectangular shape of 5 cm 2 to produce a cathode electrode.
  • PTFE polytetrafluoroethylene
  • the electrolyte membrane was sandwiched between the cathode electrode and the anode electrode, and hot pressing was performed to produce an MEA.
  • TEC10E50E manufactured by Tanaka Kikinzoku Kogyo Co., Ltd. was used for the anode electrode.
  • Example 9 A platinum-supporting carbon was prepared in the same manner as in Example 8 except that the catalyst-supporting carbon of Example 2 was used, and an MEA was prepared.
  • Durability performance evaluation Durability performance was evaluated according to the potential cycle (start / stop) test described in FCCJ's published “Proposals for Targets, R & D Issues and Evaluation Methods for Polymer Electrolyte Fuel Cells”.
  • the MEA was humidified under conditions of a temperature of 80 ° C. and a humidity of 90% RH, hydrogen was supplied to the anode electrode at 500 sccm, and oxygen was supplied to the cathode electrode at 500 sccm to perform IV measurement. After holding the potential at 1.0 V for 30 seconds, after conducting a potential cycle test of 5,000 cycles at a voltage range of 1.0 V to 1.5 V and a potential scanning speed of 0.5 V / s, an IV measurement was performed. It was.
  • Table 3 shows the evaluation results of the initial performance and durability performance of the MEAs of Examples 8 to 11 and Comparative Examples 4 to 6.
  • the MEA current density was high and the initial performance was excellent.
  • the MEA maintained a high current density even after 5,000 cycles of the potential cycle test, and was excellent in durability.

Abstract

Provided is carbon for supporting catalysts thereon which combines the excellent property of dispersedly supporting catalyst-metal particles with excellent resistance to oxidative degradation. The carbon for supporting catalysts satisfies the following requirements (a) to (d). (a) The carbon surface has a crystallite thickness Lc(002), calculated from the results of an examination by wide-angle X-ray diffractometry, of 2.0 nm or greater. (b) The carbon surface, when examined by Raman spectrometry, gives a spectrum wherein the ratio of the area of a D1-band (1,350 cm-1) peak to the area of a G-band (1,590 cm-1) peak, D/G, is 0.5-2.5. (c) The carbon has pores comprising mesopores, the volume of the mesopores being 0.35-1.3 cm3/g. (d) The ratio of the mesopore volume to the total pore volume is 0.6-1.0.

Description

触媒担持用カーボン及びその製造方法Catalyst-supporting carbon and method for producing the same
　本発明は、触媒担持用カーボン及びその製造方法に関する。
　本願は、２０１６年５月３１日に、日本に出願された特願２０１６－１０８５４２号に基づき優先権を主張し、その内容をここに援用する。 The present invention relates to a catalyst-supporting carbon and a method for producing the same.
This application claims priority on May 31, 2016 based on Japanese Patent Application No. 2016-108542 for which it applied to Japan, and uses the content here.
　燃料電池等においては、白金等の触媒金属粒子を担持する触媒担持用カーボンにカーボンブラックが広く用いられている。触媒担持用カーボンには、触媒金属粒子の分散性及び反応効率を高めるための高比表面積化、燃料電池等の高負荷な酸化電位環境での酸化分解耐性の向上等が求められる。そこで、触媒担持用カーボンとしては、例えば、以下のものが提案されている。 In fuel cells and the like, carbon black is widely used as catalyst-carrying carbon that carries catalytic metal particles such as platinum. The catalyst-supporting carbon is required to have a high specific surface area for improving the dispersibility and reaction efficiency of the catalyst metal particles, and to improve the resistance to oxidative decomposition in a high-load oxidation potential environment such as a fuel cell. Thus, for example, the following has been proposed as catalyst-supporting carbon.
　（１）カーボンブラックを熱処理して黒鉛化した後、蒸気エッチングにより高表面化した高表面積黒鉛化カーボン（特許文献１）。
　（２）比表面積が２００～１０００ｍ２／ｇ、ラマンスペクトルのＤバンド（１３５０ｃｍ－１）とＧバンド（１５８０ｃｍ－１）のピーク強度比が０．３～０．７、Ｘ線回折法の（００２）面のｃ軸方向の結晶子の大きさＬｃ（００２）が３０ｎｍ以上である改質黒鉛（特許文献２）。
　（３）比表面積が３００～１１００ｍ２／ｇ、結晶層厚み（Ｌｃ）が２５～１００Å、凝集粒子の最大径が２０μｍ以下のカーボンブラック（特許文献３）。
　（４）比表面積が５００～１１００ｍ２／ｇ、２０μｍ以上の凝集粒子が１０ｐｐｍ以下であるアセチレンブラック（特許文献４）。 (1) High surface area graphitized carbon obtained by heat treating carbon black to graphitize and then increasing the surface by vapor etching (Patent Document 1).
(2) a specific surface area of 200 ~ 1000 m 2 / g, the peak intensity ratio of D band of the Raman spectra (1350 cm -1) and G band (1580 cm -1) 0.3 to 0.7, the X-ray diffraction method ( 002) Modified graphite having a crystallite size Lc (002) in the c-axis direction of 30 nm or more (Patent Document 2).
(3) Carbon black having a specific surface area of 300 to 1100 m 2 / g, a crystal layer thickness (Lc) of 25 to 100 mm, and a maximum diameter of aggregated particles of 20 μm or less (Patent Document 3).
(4) Acetylene black having a specific surface area of 500 to 1100 m 2 / g and aggregated particles of 20 μm or more of 10 ppm or less (Patent Document 4).
特表２０１１－５１４３０４号公報Special table 2011-514304 gazette 特開２００７－２９０９３６号公報JP 2007-290936 A 特開２０１４－２１４２９０号公報JP 2014-214290 A 特開２０１３－２０９５０４号公報JP 2013-209504 A
　しかし、（１）～（４）のような触媒担持用カーボンでは、触媒金属粒子を微粒子化しカーボンに均一に分布させること（分散担持性）と、優れた酸化分解耐性とを両立することが難しい。 However, with catalyst-supporting carbons such as (1) to (4), it is difficult to make both catalyst metal particles finely distributed uniformly in the carbon (dispersion supportability) and excellent oxidative decomposition resistance. .
　本発明は、触媒金属粒子の優れた分散担持性と、優れた酸化分解耐性とが両立された触媒担持用カーボン、及び該触媒担持用カーボンの製造方法を提供することを目的とする。 An object of the present invention is to provide a catalyst-supporting carbon that has both excellent dispersion supportability of catalyst metal particles and excellent oxidative decomposition resistance, and a method for producing the catalyst-supporting carbon.
　本発明は、以下の構成を有する。
［１］下記条件（ａ）～（ｄ）を満たす触媒担持用カーボン。
　（ａ）広角Ｘ線回折法による測定結果から算出されるカーボン表面の結晶子の厚みＬｃ（００２）が２．０ｎｍ以上である。
　（ｂ）ラマン分光法によるカーボン表面のスペクトルにおけるＧ－ｂａｎｄ（１５９０ｃｍ－１）のピーク面積に対するＤ１－ｂａｎｄ（１３５０ｃｍ－１）のピーク面積の比Ｄ／Ｇが０．５～２．５である。
　（ｃ）メソ孔を含む細孔を有し、メソ孔容積が０．３５～１．３ｃｍ３／ｇである。
　（ｄ）全細孔容積に対する前記メソ孔容積の比率が０．６～１．０である。
［２］前記［１］に記載の触媒担持用カーボンを製造する方法であって、カーボンブラックを２２００℃以上で熱処理して炭素材料を得る熱処理工程と、前記熱処理工程後の炭素材料に対して表面酸化処理を行う表面酸化工程と、を有する、触媒担持用カーボンの製造方法。 The present invention has the following configuration.
[1] A catalyst-supporting carbon that satisfies the following conditions (a) to (d).
(A) The crystallite thickness Lc (002) of the carbon surface calculated from the measurement result by the wide-angle X-ray diffraction method is 2.0 nm or more.
(B) at D 1 -band (1350cm -1) ratio D / G is 0.5 of the peak area of 2.5 to the peak area of G-band of the spectrum of the carbon surface by Raman spectroscopy (1590 cm -1) is there.
(C) It has pores including mesopores, and the mesopore volume is 0.35 to 1.3 cm 3 / g.
(D) The ratio of the mesopore volume to the total pore volume is 0.6 to 1.0.
[2] A method for producing a catalyst-supporting carbon as described in [1] above, wherein a heat treatment step of obtaining a carbon material by heat-treating carbon black at 2200 ° C. or higher, and a carbon material after the heat treatment step A method for producing catalyst-supporting carbon, comprising: a surface oxidation step for performing a surface oxidation treatment.
　本発明の触媒担持用カーボンにおいては、触媒金属粒子の優れた分散担持性と、優れた酸化分解耐性とが両立されている。
　本発明の触媒担持用カーボンの製造方法によれば、触媒金属粒子の優れた分散担持性と、優れた酸化分解耐性とが両立された触媒担持用カーボンが得られる。 In the catalyst-supporting carbon of the present invention, both excellent dispersion supportability of catalyst metal particles and excellent resistance to oxidative decomposition are achieved.
According to the method for producing a catalyst-supporting carbon of the present invention, a catalyst-supporting carbon having both excellent dispersion supportability of catalyst metal particles and excellent oxidative decomposition resistance can be obtained.
［触媒担持用カーボン］
　本発明の触媒担持用カーボンは、条件（ａ）～（ｄ）を満たす。
　（ａ）広角Ｘ線回折法による測定結果から算出されるカーボン表面の結晶子の厚みＬｃ（００２）が２．０ｎｍ以上である。
　（ｂ）ラマン分光法によるカーボン表面のスペクトルにおけるＧ－ｂａｎｄ（１５９０ｃｍ－１）のピーク面積に対するＤ１－ｂａｎｄ（１３５０ｃｍ－１）のピーク面積の比Ｄ／Ｇが０．５～２．５である。
　（ｃ）メソ孔を含む細孔を有し、メソ孔容積が０．３５～１．３ｃｍ３／ｇである。
　（ｄ）全細孔容積に対するメソ孔容積の比率が０．６～１．０である。 [Catalyst-supporting carbon]
The catalyst-supporting carbon of the present invention satisfies the conditions (a) to (d).
(A) The crystallite thickness Lc (002) of the carbon surface calculated from the measurement result by the wide-angle X-ray diffraction method is 2.0 nm or more.
(B) at D 1 -band (1350cm -1) ratio D / G is 0.5 of the peak area of 2.5 to the peak area of G-band of the spectrum of the carbon surface by Raman spectroscopy (1590 cm -1) is there.
(C) It has pores including mesopores, and the mesopore volume is 0.35 to 1.3 cm 3 / g.
(D) The ratio of the mesopore volume to the total pore volume is 0.6 to 1.0.
（条件（ａ））
　本発明の触媒担持用カーボンの広角Ｘ線回折法による測定結果から算出されるカーボン表面の結晶子の厚みＬｃ（００２）は、２．０ｎｍ以上であり、３．５～４．５ｎｍが好ましい。厚みＬｃ（００２）が下限値以上であれば、酸化分解耐性（耐久性）に優れる。厚みＬｃ（００２）が上限値以下であれば、後工程である表面酸化工程での反応性に優れる。 (Condition (a))
The crystallite thickness Lc (002) on the carbon surface calculated from the measurement result of the catalyst-supporting carbon of the present invention by the wide-angle X-ray diffraction method is 2.0 nm or more, and preferably 3.5 to 4.5 nm. If thickness Lc (002) is more than a lower limit, it will be excellent in oxidative degradation tolerance (durability). If thickness Lc (002) is below an upper limit, it will be excellent in the reactivity in the surface oxidation process which is a post process.
（条件（ｂ））
　本発明の触媒担持用カーボンのラマン分光法によるカーボン表面のスペクトルにおけるＧ－ｂａｎｄ（１５９０ｃｍ－１）のピーク面積に対するＤ１－ｂａｎｄ（１３５０ｃｍ－１）のピーク面積の比Ｄ／Ｇは、０．５～２．５であり、０．８５～２．５が好ましい。比Ｄ／Ｇが下限値以上であれば、カーボン表面における結晶構造の欠損が充分に増大し、触媒の分散担持性に優れたものとなる。比Ｄ／Ｇが上限値以下であれば、欠損過多により触媒担持用カーボンの酸化分解耐性が損なわれることを抑制できる。 (Condition (b))
The ratio D / G of the peak area of D 1 -band to the peak area of G-band of the spectrum of the carbon surface by Raman spectroscopy of the catalyst-supporting carbon of the present invention (1590cm -1) (1350cm -1) is 0. 5 to 2.5, preferably 0.85 to 2.5. If the ratio D / G is equal to or greater than the lower limit, the crystal structure deficiency on the carbon surface is sufficiently increased, and the catalyst is excellent in dispersion support. If the ratio D / G is equal to or less than the upper limit value, it is possible to suppress the oxidative decomposition resistance of the catalyst-supporting carbon from being excessively lost.
（条件（ｃ））
　本発明の触媒担持用カーボンは、メソ孔を含む細孔を有する。なお、メソ孔とは、細孔径が２ｎｍ以上５０ｎｍ以下の細孔を意味するものとする。
　本発明の触媒担持用カーボンのメソ孔容積は、０．３５～１．３ｃｍ３／ｇであり、０．５～１．０ｃｍ３／ｇが好ましい。メソ孔容積が下限値以上であれば、触媒の分散担持性に優れ、触媒活性が充分に得られる。メソ孔容積が上限値以下であれば、細孔過多により触媒担持用カーボンの酸化分解耐性が損なわれることを抑制できる。なお、メソ孔容積とは、触媒担持カーボンが有する全てのメソ孔の容積の合計を意味する。 (Condition (c))
The catalyst-supporting carbon of the present invention has pores including mesopores. The mesopore means a pore having a pore diameter of 2 nm or more and 50 nm or less.
Mesopore volume of the catalyst-supporting carbon of the present invention is 0.35 ~ 1.3cm 3 / g, preferably 0.5 ~ 1.0cm 3 / g. When the mesopore volume is at least the lower limit value, the catalyst is excellent in dispersion support and sufficient catalytic activity is obtained. If the mesopore volume is less than or equal to the upper limit value, it is possible to suppress the oxidative degradation resistance of the catalyst-supporting carbon due to excessive pores. The mesopore volume means the total volume of all mesopores possessed by the catalyst-supporting carbon.
（条件（ｄ））
　本発明の触媒担持用カーボンの全細孔容積に対するメソ孔容積の比率は、０．６以上であり、０．８以上が好ましい。触媒担持用カーボンの前記比率が下限値以上であれば、触媒の分散担持性に優れ、触媒活性が充分に得られる。 (Condition (d))
The ratio of the mesopore volume to the total pore volume of the catalyst-supporting carbon of the present invention is 0.6 or more, and preferably 0.8 or more. If the ratio of the catalyst supporting carbon is equal to or higher than the lower limit value, the catalyst is excellent in dispersion supporting property and sufficient catalytic activity can be obtained.
　本発明の触媒担持用カーボンのＢＥＴ比表面積は、１３０～７００ｍ２／ｇが好ましく、２００～６００ｍ２／ｇがより好ましい。触媒担持用カーボンのＢＥＴ比表面積が下限値以上であれば、触媒の分散担持性に優れ、触媒活性が充分に得られる。触媒担持用カーボンのＢＥＴ比表面積が上限値以下であれば、後工程である表面酸化工程で処理を実施しても触媒担持用カーボンの酸化分解耐性が維持される。
　なお、触媒担持用カーボンのＢＥＴ比表面積は、ＡＳＴＭ　Ｄ　３０３７に準拠した条件で測定される。 BET specific surface area of the catalyst-supporting carbon of the present invention is preferably 130 ~ 700m 2 / g, more preferably 200 ~ 600m 2 / g. If the BET specific surface area of the catalyst supporting carbon is not less than the lower limit value, the catalyst is excellent in dispersion supporting property and sufficient catalytic activity can be obtained. If the BET specific surface area of the catalyst-supporting carbon is not more than the upper limit value, the oxidative decomposition resistance of the catalyst-supporting carbon is maintained even if the treatment is performed in the subsequent surface oxidation step.
The BET specific surface area of the catalyst-supporting carbon is measured under conditions based on ASTM D 3037.
　本発明の触媒担持用カーボンのＤＢＰ吸油量は、１５０～５００ｃｍ３／１００ｇが好ましく、２００～４５０ｃｍ３／１００ｇがより好ましい。触媒担持用カーボンのＤＢＰ吸油量が下限値以上であれば、導電性に優れる。触媒担持用カーボンのＤＢＰ吸油量が上限値以下であれば、凝集体の高度な発達を抑制し、触媒インク調製時の溶媒に対する触媒担持用カーボンの良好な分散性を維持することができる。
　なお、触媒担持用カーボンのＤＢＰ吸油量は、ＡＳＴＭ　Ｄ　２４１４に準拠した条件で、サンプル量９ｇで測定される。 DBP oil absorption amount of the catalyst-supporting carbon of the present invention is preferably 150 ~ 500cm 3 / 100g, more preferably 200 ~ 450cm 3 / 100g. When the DBP oil absorption amount of the catalyst-supporting carbon is equal to or higher than the lower limit value, the conductivity is excellent. If the DBP oil absorption amount of the catalyst-supporting carbon is not more than the upper limit value, it is possible to suppress the advanced development of the aggregate and maintain good dispersibility of the catalyst-supporting carbon in the solvent at the time of preparing the catalyst ink.
The DBP oil absorption amount of the catalyst-supporting carbon is measured with a sample amount of 9 g under the condition based on ASTM D 2414.
　本発明の触媒担持用カーボンは、一次粒子が連なった連鎖体からなる凝集体（二次粒子）で構成された粉末である。
　本発明の触媒担持用カーボンの凝集体径（モード径）は、１．０～３５．０μｍが好ましく、５．０～３０．０μｍがより好ましい。触媒担持用カーボンの凝集体径が下限値以上であれば、触媒インク調製時、金属粒子が均一に担持されやすい。また触媒担持カーボンの導電性に優れる。触媒担持用カーボンの凝集体径が上限値以下であれば、触媒インク調製時の溶媒に対する触媒担持カーボンの分散性に優れる。
　なお、凝集体径（モード径）は、ＪＩＳ　Ｋ６２１７－６に記載の凝集体径の測定方法により測定される。 The catalyst-supporting carbon of the present invention is a powder composed of aggregates (secondary particles) composed of a chain of primary particles.
The aggregate diameter (mode diameter) of the catalyst-supporting carbon of the present invention is preferably 1.0 to 35.0 μm, and more preferably 5.0 to 30.0 μm. If the aggregate diameter of the catalyst-supporting carbon is equal to or greater than the lower limit value, the metal particles are easily supported uniformly when preparing the catalyst ink. In addition, the conductivity of the catalyst-supporting carbon is excellent. If the aggregate diameter of the catalyst-supporting carbon is not more than the upper limit value, the dispersibility of the catalyst-supporting carbon in the solvent during preparation of the catalyst ink is excellent.
The aggregate diameter (mode diameter) is measured by the aggregate diameter measuring method described in JIS K6217-6.
　本発明の触媒担持用カーボンの総質量に対する凝集体径が２０μｍ以上の合計質量割合は、２０～４５質量％が好ましく、２５～４０質量％がより好ましい。前記凝集体径が２０μｍ以上の割合が下限値以上であれば、導電性に優れる。前記凝集体径が２０μｍ以上の割合が上限値以下であれば、触媒インク調製時の溶媒に対する触媒担持カーボンの分散性に優れる。 The total mass ratio of the aggregate diameter of 20 μm or more with respect to the total mass of the catalyst-supporting carbon of the present invention is preferably 20 to 45% by mass, and more preferably 25 to 40% by mass. When the aggregate diameter is 20 μm or more, the conductivity is excellent. When the ratio of the aggregate diameter of 20 μm or more is equal to or less than the upper limit value, the dispersibility of the catalyst-supporting carbon with respect to the solvent during preparation of the catalyst ink is excellent.
　本発明の触媒担持用カーボンは、燃料電池用途に好適に使用できる。
　触媒担持用カーボンに担持する触媒金属粒子としては、例えば、白金、白金との合金（ニッケル、コバルト、パラジウム、ルテニウムから選ばれる少なくとも一種以上から選ばれる白金との合金）等が挙げられ、燃料電池用途では白金が好ましい。
　触媒金属粒子の担持率は、特に限定されず、例えば、触媒担持用カーボンに触媒金属粒子を担持した触媒担持カーボンの総質量に対して、２０～５０質量％とすることができる。 The catalyst-supporting carbon of the present invention can be suitably used for fuel cell applications.
Examples of the catalyst metal particles supported on the catalyst-supporting carbon include platinum, an alloy with platinum (an alloy with platinum selected from at least one selected from nickel, cobalt, palladium, and ruthenium). Platinum is preferred for applications.
The supporting rate of the catalyst metal particles is not particularly limited, and can be, for example, 20 to 50% by mass based on the total mass of the catalyst-supporting carbon in which the catalyst-supporting carbon is supported on the catalyst-supporting carbon.
［触媒担持用カーボンの製造方法］
　本発明の触媒担持用カーボンの製造方法は、前述した本発明の触媒担持用カーボンを製造する方法である。本発明の触媒担持用カーボンの製造方法は、下記の熱処理工程と表面酸化工程とを有する。
　熱処理工程：カーボンブラックを２２００℃以上で熱処理して炭素材料を得る。
　表面酸化工程：熱処理工程後の炭素材料に対して表面酸化処理を行う。 [Method for producing catalyst-supporting carbon]
The method for producing catalyst-supporting carbon of the present invention is a method for producing the catalyst-supporting carbon of the present invention described above. The method for producing catalyst-supporting carbon of the present invention includes the following heat treatment step and surface oxidation step.
Heat treatment process: Carbon black is heat-treated at 2200 ° C. or higher to obtain a carbon material.
Surface oxidation process: A surface oxidation process is performed on the carbon material after the heat treatment process.
（熱処理工程）
　熱処理工程では、カーボンブラックを２２００℃以上で熱処理して炭素材料を得る。この熱処理により、カーボンブラックが高結晶化される。
　熱処理温度は、２２００℃以上であり、２２００～３５００℃が好ましく、２２００～３０００℃がより好ましい。熱処理温度が下限値以上であれば、カーボンブラックが充分に高結晶化され、条件（ａ）を満たす触媒担持用カーボンが得られる。熱処理温度が上限値以下であれば、後工程である表面酸化処理での反応性に優れる。 (Heat treatment process)
In the heat treatment step, carbon black is heat-treated at 2200 ° C. or higher to obtain a carbon material. By this heat treatment, the carbon black is highly crystallized.
The heat treatment temperature is 2200 ° C. or higher, preferably 2200 to 3500 ° C., more preferably 2200 to 3000 ° C. When the heat treatment temperature is equal to or higher than the lower limit, the carbon black is sufficiently crystallized, and catalyst-supporting carbon that satisfies the condition (a) is obtained. If heat processing temperature is below an upper limit, it will be excellent in the reactivity in the surface oxidation process which is a post process.
　熱処理時間は、熱処理温度に応じて適宜設定すればよく、例えば、１～３０時間とすることができる。 The heat treatment time may be appropriately set according to the heat treatment temperature, and may be, for example, 1 to 30 hours.
　原料であるカーボンブラックとしては、条件（ａ）～（ｄ）を満たす触媒担持用カーボンが得られやすい点から、ケッチェンブラックが好ましい。なお、ケッチェンブラック以外のカーボンブラックを用いてもよい。 As the raw material carbon black, ketjen black is preferable because it is easy to obtain catalyst-supporting carbon that satisfies the conditions (a) to (d). Carbon black other than ketjen black may be used.
　カーボンブラックのＢＥＴ比表面積は、５０～２０００ｍ２／ｇが好ましく、１００～１５００ｍ２／ｇがより好ましく、７００～１５００ｍ２／ｇがさらに好ましい。カーボンブラックのＢＥＴ比表面積が前記範囲内であれば、条件（ａ）～（ｄ）を満たす触媒担持用カーボンが得られやすい。
　なお、カーボンブラックのＢＥＴ比表面積は、ＡＳＴＭ　Ｄ　３０３７に準拠した条件で測定される。 BET specific surface area of the carbon black is preferably 50 ~ 2000m 2 / g, more preferably 100 ~ 1500m 2 / g, more preferably 700 ~ 1500m 2 / g. If the BET specific surface area of the carbon black is within the above range, it is easy to obtain catalyst-supporting carbon that satisfies the conditions (a) to (d).
In addition, the BET specific surface area of carbon black is measured on the conditions based on ASTM D3037.
　カーボンブラックのＤＢＰ吸油量は、２００～６００ｃｍ３／１００ｇが好ましく、２５０～５００ｃｍ３／１００ｇがより好ましい。カーボンブラックのＤＢＰ吸油量が下限値以上であれば、導電性に優れる。カーボンブラックのＤＢＰ吸油量が上限値以下であれば、凝集体の高度な発達を抑制し、触媒インク調製時に溶媒に対する触媒担持用カーボンの良好な分散性を維持することができる。
　なお、カーボンブラックのＤＢＰ吸油量は、ＡＳＴＭ　Ｄ　２４１４に準拠した条件で、サンプル量９ｇで測定される値である。 DBP oil absorption of carbon black is preferably 200 ~ 600cm 3 / 100g, more preferably 250 ~ 500cm 3 / 100g. If the DBP oil absorption of carbon black is not less than the lower limit value, the conductivity is excellent. If the DBP oil absorption of carbon black is less than or equal to the upper limit value, the advanced development of aggregates can be suppressed, and good dispersibility of the catalyst-supporting carbon in the solvent can be maintained when preparing the catalyst ink.
Note that the DBP oil absorption of carbon black is a value measured with a sample amount of 9 g under conditions based on ASTM D 2414.
　カーボンブラックは、一次粒子が葡萄房状に連なった連鎖体からなる二次粒子で構成された粉末である。
　カーボンブラックの平均一次粒子径は、５～１００ｎｍが好ましく、２０～６０ｎｍがより好ましい。カーボンブラックの平均一次粒子径が前記範囲内であれば、触媒担持用カーボンの比表面積が増加し、触媒金属粒子を担持させる時の活性点が増加する。なお、カーボンブラックの平均一次粒子径は、透過型電子顕微鏡で観察した画像においてランダムに１０００個以上の粒子径を測定して平均した値である。 Carbon black is a powder composed of secondary particles composed of a chain of primary particles connected in a kitchen shape.
The average primary particle size of carbon black is preferably 5 to 100 nm, more preferably 20 to 60 nm. If the average primary particle diameter of the carbon black is within the above range, the specific surface area of the catalyst-supporting carbon increases, and the active point when supporting the catalyst metal particles increases. In addition, the average primary particle diameter of carbon black is a value obtained by measuring 1000 or more particle diameters randomly in an image observed with a transmission electron microscope.
　カーボンブラックの凝集体径（モード径）は、１．０～３５．０μｍが好ましく、５．０～３０．０μｍがより好ましい。カーボンブラックのモード径が前記範囲内であれば、触媒インク調製時の溶媒に対する触媒担持カーボンの分散性に優れ、触媒金属粒子が均一に担持されやすい。 The aggregate diameter (mode diameter) of carbon black is preferably 1.0 to 35.0 μm, more preferably 5.0 to 30.0 μm. If the mode diameter of the carbon black is within the above range, the catalyst-supporting carbon is excellent in dispersibility in the solvent at the time of catalyst ink preparation, and the catalyst metal particles are easily supported uniformly.
　カーボンブラックの揮発分は、５質量％以下が好ましく、２質量％以下がより好ましい。カーボンブラックの揮発分が上限値以下であれば、後工程である表面酸化処理において官能基の種類を抑制できる。 The volatile content of carbon black is preferably 5% by mass or less, and more preferably 2% by mass or less. If the volatile content of carbon black is less than or equal to the upper limit value, the type of functional group can be suppressed in the surface oxidation treatment as a post process.
　なお、カーボンブラックの揮発分は、ＡＳＴＭ　Ｄ　１６２０－６０に準拠した方法で測定される。
　磁性るつぼ（直径１５ｍｍ、高さ３０ｍｍ、容量１０ｍＬ）及び落とし蓋を９５０±２０℃で３０分間空焼きした後、デシケータ中で室温（２５℃）まで冷却し、該磁性るつぼ及び落とし蓋の質量（ＭＡ）を０．１ｍｇ単位まで正確に秤量する。次いで、カーボンブラック２ｇを、磁性るつぼ中に蓋下２ｍｍを越えない程度に押し詰めて落とし蓋をし、その質量（ＭＢ）を０．１ｍｇ単位まで正確に秤量する。次いで、磁性るつぼを９５０±２０℃の電気炉で７分間加熱し、デシケータ中で室温（２５℃）まで冷却して、再度、質量（ＭＣ）を０．１ｍｇ単位まで正確に秤量して、以下の式により揮発分を算出する。
　揮発分（質量％）＝（ＭＢ－ＭＣ）／（ＭＢ－ＭＡ） The volatile content of carbon black is measured by a method based on ASTM D 1620-60.
The magnetic crucible (diameter 15 mm, height 30 mm, capacity 10 mL) and the drop lid were baked at 950 ± 20 ° C. for 30 minutes, then cooled to room temperature (25 ° C.) in a desiccator, and the mass of the magnetic crucible and drop lid ( Weigh accurately M A ) to the nearest 0.1 mg. Then, the carbon black 2g, capped off by Oshitsume to the extent not exceeding the lid under 2mm in a porcelain crucible, accurately weighed its mass (M B) to 0.1mg units. The magnetic crucible is then heated in an electric furnace at 950 ± 20 ° C. for 7 minutes, cooled to room temperature (25 ° C.) in a desiccator, and the mass (M C ) is accurately weighed to the nearest 0.1 mg, The volatile content is calculated by the following formula.
Volatile content (mass%) = (M B −M C ) / (M B −M A )
　カーボンブラックの灰分は、０．５質量％以下が好ましく、０．２質量％以下がより好ましい。カーボンブラックの灰分が上限値以下であれば、不純物が少なく、導電性に優れる。
　なお、カーボンブラックの灰分は、ＡＳＴＭ　Ｄ　１５０６に準拠した方法で測定される。 The ash content of carbon black is preferably 0.5% by mass or less, and more preferably 0.2% by mass or less. If the ash content of carbon black is less than or equal to the upper limit value, the impurities are small and the conductivity is excellent.
The ash content of carbon black is measured by a method based on ASTM D 1506.
　カーボンブラックとしては、条件（ａ）～（ｄ）を満たす触媒担持用カーボンが得られやすい点から、ＢＥＴ比表面積が７００～１５００ｍ２／ｇであるケッチェンブラックが特に好ましい。 As the carbon black, ketjen black having a BET specific surface area of 700 to 1500 m 2 / g is particularly preferable because a catalyst-supporting carbon satisfying the conditions (a) to (d) can be easily obtained.
（表面酸化工程）
　表面酸化工程では、熱処理工程で得た炭素材料に対して表面酸化処理を行う。これにより、炭素材料のカーボン表面において結晶構造に欠損が生じて表面積が大きくなり、官能基が導入される。 (Surface oxidation process)
In the surface oxidation step, surface oxidation treatment is performed on the carbon material obtained in the heat treatment step. Thereby, defects are generated in the crystal structure on the carbon surface of the carbon material, the surface area is increased, and a functional group is introduced.
　表面酸化処理方法としては、特に限定されず、酸化剤を含む水溶液に炭素材料を接触させる方法が挙げられる。炭素材料を接触させる際の酸化剤を含む水溶液は、液体状態であってもよく、亜臨界状態であってもよく、超臨界状態であってもよい。 The surface oxidation treatment method is not particularly limited, and examples thereof include a method of bringing a carbon material into contact with an aqueous solution containing an oxidizing agent. The aqueous solution containing an oxidizing agent when contacting the carbon material may be in a liquid state, a subcritical state, or a supercritical state.
　処理時間は、処理方法及び酸化剤の種類等に応じて適宜決定できる。例えば、酸化剤を含む水溶液を液体状態とする場合の処理時間は１～３０時間とすることができる。酸化剤を含む水溶液を亜臨界状態又は超臨界状態とする場合の処理時間は０．５時間以上とすることができる。 The treatment time can be appropriately determined according to the treatment method, the type of oxidizing agent, and the like. For example, the treatment time when an aqueous solution containing an oxidizing agent is in a liquid state can be 1 to 30 hours. When the aqueous solution containing the oxidizing agent is brought into the subcritical state or the supercritical state, the treatment time can be 0.5 hours or longer.
　酸化剤の量は、酸化剤を含む水溶液の総質量に対し、２～２０質量％とすることができる。 The amount of the oxidizing agent can be 2 to 20% by mass with respect to the total mass of the aqueous solution containing the oxidizing agent.
　酸化剤としては、特に限定されず、例えば、過酸化水素、過硫酸アンモニウム、過硫酸ナトリウム、硝酸、塩酸、硫酸等が挙げられる。なかでも、過酸化水素、過硫酸アンモニウム、過硫酸ナトリウムが好ましい。酸化剤としては、１種を単独で使用してもよく、２種以上を併用してもよい。 The oxidizing agent is not particularly limited, and examples thereof include hydrogen peroxide, ammonium persulfate, sodium persulfate, nitric acid, hydrochloric acid, sulfuric acid and the like. Of these, hydrogen peroxide, ammonium persulfate, and sodium persulfate are preferable. As an oxidizing agent, 1 type may be used independently and 2 or more types may be used together.
　酸化剤を含む水溶液による表面酸化処理後は、必要に応じて水による洗浄を行った後、乾燥することで粉末状の触媒担持用カーボンが得られる。 After surface oxidation treatment with an aqueous solution containing an oxidizing agent, washing with water is performed as necessary, followed by drying to obtain powdery catalyst-supporting carbon.
　以上説明した本発明の触媒担持用カーボンは、条件（ａ）～（ｄ）を満たしているため、優れた触媒分散性及び酸化分解耐性を兼ね備えている。 The catalyst-supporting carbon of the present invention described above satisfies the conditions (a) to (d), and therefore has excellent catalyst dispersibility and resistance to oxidative decomposition.
［触媒の担持方法］
　本発明の触媒担持用カーボンに触媒金属粒子を担持させる方法としては、公知の方法を用いることができる。
　例えば、金属錯体を含む溶媒中に触媒担持用カーボンを加えて、カーボン表面に金属錯体を吸着させた後、不活性ガス雰囲気下での熱処理、又は還元雰囲気下での熱処理を行う方法が挙げられる。また、金属錯体を含む溶媒中に有機酸、アルコール、エチレングリコール等の還元剤を混合して金属コロイド粒子を生成させ、そこに触媒担持用カーボンを加えてカーボン表面に金属コロイド粒子を付着させる方法や、金属錯体を含む溶媒中に触媒担持用カーボンを加えてから還元剤を添加し、カーボン表面に金属コロイド粒子を生成させる沈殿法を用いることができる。触媒担持用カーボンには、触媒金属粒子を担持させる前に予め親水化処理や疎水化処理を行ってもよく、また、触媒担持用カーボンに触媒金属粒子を担持した後に熱処理や酸処理を行ってもよい。 [Catalyst loading method]
As a method of supporting the catalyst metal particles on the catalyst-supporting carbon of the present invention, a known method can be used.
For example, a method of performing a heat treatment in an inert gas atmosphere or a heat treatment in a reducing atmosphere after adding a catalyst-supporting carbon in a solvent containing a metal complex and adsorbing the metal complex on the carbon surface. . Also, a method of adhering metal colloidal particles to the surface of a carbon by adding a catalyst-supporting carbon to a metal colloidal particle by mixing a reducing agent such as an organic acid, alcohol or ethylene glycol in a solvent containing a metal complex. Alternatively, a precipitation method may be used in which a catalyst is added to a solvent containing a metal complex and then a reducing agent is added to form metal colloid particles on the carbon surface. The catalyst-supporting carbon may be subjected to a hydrophilization treatment or a hydrophobization treatment in advance before the catalyst metal particles are supported, and after the catalyst metal particles are supported on the catalyst-supporting carbon, a heat treatment or an acid treatment is performed. Also good.
　以下、実施例によって本発明を詳細に説明するが、本発明は以下の記載によっては限定されない。
［原料］
　本実施例で使用した原料を以下に示す。
（カーボンブラック）
　Ａ－１：製品名「ＥＣ６００ＪＤ」（ケッチェンブラック、ＢＥＴ比表面積：１４００ｍ２／ｇ、ＤＢＰ吸油量：４９５ｃｍ３／１００ｇ、揮発分：０．５質量％、灰分：０．０２質量％、平均一次粒子径：３４ｎｍ、ライオン・スペシャリティ・ケミカルズ株式会社製）。
　Ａ－２：製品名「ＥＣ３００Ｊ」（ケッチェンブラック、ＢＥＴ比表面積：８００ｍ２／ｇ、ＤＢＰ吸油量：３６５ｃｍ３／１００ｇ、揮発分：０．４質量％、灰分：０．０２質量％、平均一次粒子径：４０ｎｍ、ライオン・スペシャリティ・ケミカルズ株式会社製）。
　Ａ－３：製品名「デンカブラック５０％プレス」（アセチレンブラック、ＢＥＴ比表面積：６５ｍ２／ｇ、平均一次粒子径：３６ｎｍ、灰分：０．０１質量％、デンカ株式会社製）。 EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited by the following description.
[material]
The raw materials used in this example are shown below.
(Carbon black)
A-1: product name "EC600JD" (Ketjen Black, BET specific surface area: 1400 m 2 / g, DBP oil absorption: 495cm 3 / 100g, volatile matter: 0.5 wt%, ash content: 0.02 wt%, average Primary particle size: 34 nm, manufactured by Lion Specialty Chemicals).
A-2: product name "EC300J" (Ketjenblack, BET specific surface area: 800 m 2 / g, DBP oil absorption: 365cm 3 / 100g, volatile matter: 0.4 wt%, ash content: 0.02 wt%, average Primary particle size: 40 nm, manufactured by Lion Specialty Chemicals).
A-3: Product name “Denka Black 50% Press” (acetylene black, BET specific surface area: 65 m 2 / g, average primary particle size: 36 nm, ash content: 0.01% by mass, manufactured by DENKA CORPORATION).
　なお、揮発分と灰分については下記のように測定した。
［揮発分の測定法］
　ＡＳＴＭ　Ｄ　１６２０－６０に準拠した方法で測定した。
　磁性るつぼ（直径１５ｍｍ、高さ３０ｍｍ、容量１０ｍＬ）及び落とし蓋を９５０±２０℃で３０分間空焼きした後、デシケータ中で室温（２５℃）まで冷却し、該磁性るつぼ及び落とし蓋の質量（ＭＡ）を０．１ｍｇ単位まで正確に秤量した。次いで、カーボンブラック２ｇを、磁性るつぼ中に蓋下２ｍｍを越えない程度に押し詰めて落とし蓋をし、その質量（ＭＢ）を０．１ｍｇ単位まで正確に秤量した。次いで、磁性るつぼを９５０±２０℃の電気炉で７分間加熱し、デシケータ中で室温（２５℃）まで冷却して、再度、質量（ＭＣ）を０．１ｍｇ単位まで正確に秤量して、以下の式により揮発分を算出した。
　　揮発分（質量％）＝（ＭＢ－ＭＣ）／（ＭＢ－ＭＡ） The volatile content and ash content were measured as follows.
[Measurement method of volatile matter]
It was measured by a method according to ASTM D 1620-60.
The magnetic crucible (diameter 15 mm, height 30 mm, capacity 10 mL) and the drop lid were baked at 950 ± 20 ° C. for 30 minutes, then cooled to room temperature (25 ° C.) in a desiccator, and the mass of the magnetic crucible and drop lid ( M A ) was accurately weighed to the nearest 0.1 mg. Next, 2 g of carbon black was pressed into a magnetic crucible so as not to exceed 2 mm below the lid, and the lid was dropped, and the mass (M B ) was accurately weighed to the nearest 0.1 mg. The magnetic crucible is then heated in an electric furnace at 950 ± 20 ° C. for 7 minutes, cooled to room temperature (25 ° C.) in a desiccator, and the mass (M C ) is accurately weighed to the nearest 0.1 mg, Volatile content was calculated by the following formula.
Volatile content (mass%) = (M B −M C ) / (M B −M A )
［灰分の測定法］
　ＡＳＴＭ　Ｄ　１５０６に準拠した方法で測定した。 [Measurement method of ash]
It was measured by a method based on ASTM D 1506.
［実施例１］
　熱処理工程：
　カーボンブラック（Ａ－１）を焼成炉に導入し、２８００℃で１２時間熱処理を行った後、室温まで放冷し、炭素材料を得た。
　表面酸化工程：
　熱処理工程で得た炭素材料１ｇと、５％過酸化水素水約１００ｍＬとを耐高圧容器に投入した。耐高圧容器に蓋をして昇温を開始し、３５０℃に到達した時点から５％過酸化水素水を１．８ｍＬ／分で１５０分間追加導入しながら容器内の圧力を２５ＭＰａまで上昇させた。３５０℃、２５ＭＰａの状態で１時間保持した後、耐高圧容器を放冷し、容器内が常温、常圧であることを確認してから容器を開き、炭素材料の分散液を取り出した。次いで、分散液をろ過し、ろ過後の炭素材料を１１０℃で２４時間減圧（１ｍｍＨｇ以下）乾燥させ、粉末状の触媒担持用カーボンを得た。 [Example 1]
Heat treatment process:
Carbon black (A-1) was introduced into a firing furnace, heat-treated at 2800 ° C. for 12 hours, and then allowed to cool to room temperature to obtain a carbon material.
Surface oxidation process:
1 g of the carbon material obtained in the heat treatment step and about 100 mL of 5% hydrogen peroxide water were put into a high pressure resistant container. The temperature was increased by covering the high pressure resistant container, and when the temperature reached 350 ° C., the pressure inside the container was increased to 25 MPa while additionally introducing 5% hydrogen peroxide water at 1.8 mL / min for 150 minutes. . After maintaining at 350 ° C. and 25 MPa for 1 hour, the high pressure resistant container was allowed to cool, and after confirming that the inside of the container was at normal temperature and normal pressure, the container was opened and the carbon material dispersion was taken out. Next, the dispersion was filtered, and the filtered carbon material was dried under reduced pressure (1 mmHg or less) at 110 ° C. for 24 hours to obtain powdery catalyst-supporting carbon.
［実施例２］
　熱処理工程：
　実施例１と同様にして炭素材料を得た。
　表面酸化工程：
　熱処理工程で得た炭素材料１ｇを、１ｍｏｌ／Ｌ過硫酸アンモニウム水溶液１００ｍＬに分散させ、３０℃で２４時間撹拌した。撹拌終了後、分散液を室温でろ過し、炭素材料を超純水でろ液がｐＨ７になるまで洗浄した。洗浄後の炭素材料を１１０℃で減圧乾燥させ、粉末状の触媒担持用カーボンを得た。 [Example 2]
Heat treatment process:
A carbon material was obtained in the same manner as in Example 1.
Surface oxidation process:
1 g of the carbon material obtained in the heat treatment step was dispersed in 100 mL of a 1 mol / L ammonium persulfate aqueous solution and stirred at 30 ° C. for 24 hours. After completion of stirring, the dispersion was filtered at room temperature, and the carbon material was washed with ultrapure water until the filtrate reached pH 7. The washed carbon material was dried under reduced pressure at 110 ° C. to obtain powdery catalyst-supporting carbon.
［実施例３］
　熱処理温度を２２００℃に変更した以外は、実施例１と同様の熱処理工程を実施して炭素材料を得た。次いで、実施例２と同様の表面酸化工程を実施して粉末状の触媒担持用カーボンを得た。 [Example 3]
Except for changing the heat treatment temperature to 2200 ° C., the same heat treatment step as in Example 1 was performed to obtain a carbon material. Next, the same surface oxidation step as in Example 2 was performed to obtain powdery catalyst-supporting carbon.
［実施例４］
　熱処理温度を２２００℃に変更した以外は、実施例１と同様の熱処理工程を実施して炭素材料を得た。次いで、実施例１と同様の表面酸化工程を実施して粉末状の触媒担持用カーボンを得た。 [Example 4]
Except for changing the heat treatment temperature to 2200 ° C., the same heat treatment step as in Example 1 was performed to obtain a carbon material. Next, the same surface oxidation step as in Example 1 was performed to obtain powdery catalyst-supporting carbon.
［実施例５］
　カーボンブラック（Ａ－２）を使用した以外は、実施例１と同様の熱処理工程を実施して炭素材料を得た。次いで、実施例２と同様の表面酸化工程を実施して粉末状の触媒担持用カーボンを得た。 [Example 5]
A carbon material was obtained by carrying out the same heat treatment step as in Example 1 except that carbon black (A-2) was used. Next, the same surface oxidation step as in Example 2 was performed to obtain powdery catalyst-supporting carbon.
［実施例６］
　熱処理温度を２５００℃に変更した以外は、実施例１と同様の熱処理工程を実施して炭素材料を得た。次いで、実施例２と同様の表面酸化工程を実施して粉末状の触媒担持用カーボンを得た。 [Example 6]
Except for changing the heat treatment temperature to 2500 ° C., the same heat treatment step as in Example 1 was performed to obtain a carbon material. Next, the same surface oxidation step as in Example 2 was performed to obtain powdery catalyst-supporting carbon.
［実施例７］
　カーボンブラック（Ａ－３）を使用し、実施例２と同様の表面酸化工程を実施して粉末状の触媒担持用カーボンを得た。 [Example 7]
Using carbon black (A-3), the same surface oxidation step as in Example 2 was performed to obtain powdery catalyst-supporting carbon.
［比較例１］
　カーボンブラック（Ａ－２）を使用した以外は、実施例１と同様の熱処理工程を実施して炭素材料を得て、これを触媒担持用カーボンとした。 [Comparative Example 1]
Except for using carbon black (A-2), the same heat treatment step as in Example 1 was performed to obtain a carbon material, which was used as catalyst-supporting carbon.
［比較例２］
　未処理のカーボンブラック（Ａ－２）を触媒担持用カーボンとした。 [Comparative Example 2]
Untreated carbon black (A-2) was used as catalyst-supporting carbon.
［比較例３］
　カーボンブラック（Ａ－２）を使用した以外は、実施例１と同様の熱処理工程を実施して炭素材料を得た。熱処理工程で得られた炭素材料１ｇを濃硝酸２００ｍＬに分散させ、室温で超音波（２３ＭＨｚ）処理を６時間行った後、引き続き室温で９６時間撹拌した。撹拌終了後、分散液をろ過し、炭素材料を超純水でろ液がｐＨ７になるまで洗浄した。洗浄後の炭素材料を１１０℃で減圧乾燥させ、粉末状の触媒担持用カーボンを得た。 [Comparative Example 3]
A carbon material was obtained by carrying out the same heat treatment step as in Example 1 except that carbon black (A-2) was used. 1 g of the carbon material obtained in the heat treatment step was dispersed in 200 mL of concentrated nitric acid, subjected to ultrasonic treatment (23 MHz) at room temperature for 6 hours, and then stirred at room temperature for 96 hours. After completion of the stirring, the dispersion was filtered, and the carbon material was washed with ultrapure water until the filtrate reached pH 7. The washed carbon material was dried under reduced pressure at 110 ° C. to obtain powdery catalyst-supporting carbon.
［測定法］
（１）カーボン表面の結晶子の厚みＬｃ（００２）（厚さ方向の厚み）
　触媒担持用カーボンにおけるカーボン表面の結晶子の厚みＬｃ（００２）は広角Ｘ線回折法により求めた。具体的には、Ｘ線回折装置（スペクトリス株式会社製）により触媒担持用カーボンの測定を実施し、００２面の回折線ピークを得た。この００２回折線の回折角及び半値幅を下記のｓｈｅｒｒｅｒの式に代入し、カーボン表面の結晶子の厚みＬｃ（００２）（厚さ方向の厚み）（ｎｍ）を算出した。
　Ｌｃ＝κλ／βｃｏｓθ
　ただし、前記式中、κは形状因子でκ＝０．９であり、λはＸ線の波長（ｎｍ）であり、βは００２回折線の半値幅（ｎｍ）であり、θは００２回折線の回折角（°）である。 [Measurement method]
(1) Crystalline thickness Lc (002) of carbon surface (thickness in thickness direction)
The crystallite thickness Lc (002) of the carbon on the catalyst-supporting carbon was determined by a wide-angle X-ray diffraction method. Specifically, the catalyst-supporting carbon was measured using an X-ray diffractometer (Spectris Co., Ltd.), and a diffraction line peak on the 002 plane was obtained. The diffraction angle and half-value width of this 002 diffraction line were substituted into the following Serrer equation to calculate the crystallite thickness Lc (002) (thickness in the thickness direction) (nm) on the carbon surface.
Lc = κλ / βcosθ
In the above formula, κ is a shape factor and κ = 0.9, λ is the wavelength (nm) of X-rays, β is the half width (nm) of the 002 diffraction line, and θ is the 002 diffraction line. Is the diffraction angle (°).
（２）ラマンピーク強度比（Ｄ／Ｇ）
　レーザーラマン分光光度計ＮＲＳ－５１００（日本分光株式会社製）により、表１に示す条件で触媒担持用カーボンにおけるカーボン表面（厚さ数ｎｍ）の結晶状態を測定した。カーボン表面の結晶状態に欠損がある場合、対称性が乱れることにより、グラファイトの欠損（エッジ部分）に由来するＤ１－ｂａｎｄ（１３５０ｃｍ－１）のラマンピークが検出される。グラファイトのラマン活性の振動モードに由来するＧ－ｂａｎｄ（１５９０ｃｍ－１）とＤ１－ｂａｎｄの強度比（Ｄ／Ｇ）を、それぞれのピークの面積比として算出した。 (2) Raman peak intensity ratio (D / G)
Using a laser Raman spectrophotometer NRS-5100 (manufactured by JASCO Corporation), the crystal state of the carbon surface (thickness of several nm) in the catalyst-supporting carbon was measured under the conditions shown in Table 1. When there is a defect in the crystal state of the carbon surface, the symmetry is disturbed, so that a D 1 -band (1350 cm −1 ) Raman peak derived from the defect (edge part) of graphite is detected. The intensity ratio (D / G) of G-band (1590 cm −1 ) and D 1 -band derived from the vibration mode of the Raman activity of graphite was calculated as the area ratio of each peak.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
（３）細孔（メソ孔、ミクロ孔）容積
　触媒担持用カーボンの細孔分布をＢＥＬＳＯＲＰ－ｍａｘ（マイクロトラック・ベル株式会社製）により測定した。メソ孔（細孔サイズ２～５０ｎｍ）の分布及びメソ孔容積はＤＨ法、ミクロ孔（細孔サイズ２ｎｍ未満）容積はＤＡ法により解析した。全細孔容積は、算出したメソ孔容積とミクロ孔容積の合計とした。 (3) Volume of pores (mesopores, micropores) The pore distribution of the catalyst-supporting carbon was measured by BELSORP-max (manufactured by Microtrack Bell). Distribution of mesopores (pore size 2 to 50 nm) and mesopore volume were analyzed by DH method, and micropore (pore size less than 2 nm) volume was analyzed by DA method. The total pore volume was the sum of the calculated mesopore volume and micropore volume.
（４）ＢＥＴ比表面積
　触媒担持用カーボンのＢＥＴ比表面積は、ＡＳＴＭ　Ｄ　３０３７に準拠した条件で測定した。 (4) BET specific surface area The BET specific surface area of the catalyst-supporting carbon was measured under conditions based on ASTM D 3037.
（５）カーボン減少量
　触媒担持用カーボンに含まれる官能基量を見積もるために、触媒担持用カーボンを窒素雰囲気中で昇温したときのカーボンの減少量を測定した。カーボン約２０ｍｇをＴＧ－ＤＴＡ２０００ＳＡ（ネッチ・ジャパン株式会社（旧ブルカー・ＡＸＳ株式会社製）により１０℃／分で９５０℃まで昇温し、その際のカーボンの減少量（％）を測定した。 (5) Carbon reduction amount In order to estimate the functional group amount contained in the catalyst-carrying carbon, the carbon reduction amount was measured when the catalyst-carrying carbon was heated in a nitrogen atmosphere. About 20 mg of carbon was heated to 950 ° C. at 10 ° C./min by TG-DTA2000SA (Netch Japan Co., Ltd. (formerly Bruker AXS Co., Ltd.)), and the amount (%) of carbon reduction at that time was measured.
（６）ＤＢＰ吸油量
　触媒担持用カーボンのＤＢＰ吸油量は、ＡＳＴＭ　Ｄ　２４１４に準拠した条件で、サンプル量９ｇで測定した。 (6) DBP Oil Absorption The DBP oil absorption of the catalyst-supporting carbon was measured with a sample amount of 9 g under the conditions based on ASTM D 2414.
（７）凝集体径
　触媒担持用カーボンの凝集体径は、ＪＩＳ　Ｋ６２１７－６に記載の凝集体径の測定方法により測定した。 (7) Aggregate Diameter The aggregate diameter of the catalyst-supporting carbon was measured by the aggregate diameter measuring method described in JIS K6217-6.
［評価法］
（１）触媒作製方法
　ビス（アセチルアセトナト）白金（ＩＩ）を６０ｍｇと、触媒担持用カーボン０．１ｇとをジクロロメタン４０ｍＬに加え、超音波（２３ｋＨｚ）を６０分間当てて分散させた後、エバポレータ（常圧、６０℃）によりジクロロメタンを除去して白金担持カーボンの前駆体を得た。窒素雰囲気下において、前記白金担持カーボンの前駆体を２１０℃で３時間焼成した後、続けて２４０℃で３時間焼成し、白金担持カーボンを調製した。前記の焼成における昇温速度は５℃／分とした。 [Evaluation method]
(1) Catalyst preparation method 60 mg of bis (acetylacetonato) platinum (II) and 0.1 g of catalyst-supporting carbon are added to 40 mL of dichloromethane and dispersed by applying ultrasonic waves (23 kHz) for 60 minutes, and then an evaporator. The dichloromethane was removed by (normal pressure, 60 ° C.) to obtain a platinum-supported carbon precursor. In a nitrogen atmosphere, the platinum-supported carbon precursor was calcined at 210 ° C. for 3 hours, and then calcined at 240 ° C. for 3 hours to prepare platinum-supported carbon. The heating rate in the firing was 5 ° C./min.
（２）白金粒径と白金担持率の算出
　白金粒径は、Ｘ線回折法で測定して得られたスペクトルのうちＰｔ（１１１）面のピークの半値幅から、Ｓｃｈｅｒｒｅｒの式を用いて算出した。白金担持率は、ＴＧ－ＤＴＡ２０００ＳＡ（ネッチ・ジャパン株式会社（旧ブルカー・ＡＸＳ株式会社）製）により、空気中において白金担持カーボンを昇温速度１０℃／分で９５０℃まで昇温させたときに残存する白金量から算出した。 (2) Calculation of platinum particle size and platinum loading rate The platinum particle size is calculated from the half-value width of the peak of the Pt (111) plane in the spectrum obtained by the X-ray diffraction method, using the Scherrer equation. did. The platinum loading rate is determined when TG-DTA2000SA (manufactured by Netch Japan Co., Ltd. (former Bruker AXS Co., Ltd.)) raises the temperature of platinum-supported carbon to 950 ° C. at a heating rate of 10 ° C./min. Calculated from the amount of platinum remaining.
（３）電気化学的有効表面積（Electrochemical Surface Area: ECSA）
　触媒担持用カーボンの電気化学的有効表面積（ＥＣＳＡ）の測定は、燃料電池実用化推進協議会（ＦＣＣＪ）が公開しているプロトコルに従った。測定装置はポテンショスタット：Versa STAT4（株式会社東陽テクニカ製）と回転電極：RRDE-3A Rotating Ring Disk Electrode（ビー・エー・エス株式会社製）を使用した。０．１Ｍに調整した過塩素酸でガラスセルを満たし、６０℃に加温しながら、ガラスセル内に窒素を３０分間バブリングした。該過塩素酸を用いて、カーボン表面のクリーニングとＥＣＳＡの測定のため、０．０５～１．２０Ｖ　ｖｓ　ＲＨＥ、５０ｍＶ／ｓの条件で電極の回転数をゼロとしてサイクリックボルタンメトリー（ＣＶ）を実施した。再現性のあるボルタモグラム（５０サイクル実施）が得られたら、最後のサイクルにおけるボルタンメトリーからＥＣＳＡ（ｍ２／ｇＰｔ）の初期値を算出した。ＥＣＳＡ（初期値）の判定は以下の基準で行った。
　＜判定基準＞
　◎：ＥＣＳＡ（初期値）が８０ｍ２／ｇＰｔ以上である。
　○：ＥＣＳＡ（初期値）が４０ｍ２／ｇＰｔ以上８０ｍ２／ｇＰｔ未満である。
　×：ＥＣＳＡ（初期値）が４０ｍ２／ｇＰｔ未満である。 (3) Electrochemical surface area (ECSA)
The electrochemical effective surface area (ECSA) of the catalyst-supporting carbon was measured according to a protocol published by the Council for Promotion of Commercialization of Fuel Cells (FCCJ). The potentiostat: Versa STAT4 (manufactured by Toyo Technica Co., Ltd.) and the rotating electrode: RRDE-3A Rotating Ring Disk Electrode (manufactured by BAS Co., Ltd.) were used as measuring devices. The glass cell was filled with perchloric acid adjusted to 0.1 M, and nitrogen was bubbled into the glass cell for 30 minutes while heating to 60 ° C. Using this perchloric acid, cyclic voltammetry (CV) was performed with the electrode rotation speed set to zero under the conditions of 0.05 to 1.20 V vs. RHE and 50 mV / s for carbon surface cleaning and ECSA measurement. did. When a reproducible voltammogram (50 cycles performed) was obtained, the initial value of ECSA (m 2 / gPt) was calculated from voltammetry in the last cycle. ECSA (initial value) was determined according to the following criteria.
<Criteria>
A: ECSA (initial value) is 80 m 2 / gPt or more.
○: ECSA (initial value) is 40 m 2 / gPt or more and less than 80 m 2 / gPt.
X: ECSA (initial value) is less than 40 m 2 / gPt.
（４）ＥＣＳＡ維持率（耐久性、電極寿命の指標）
　ＥＣＳＡ維持率の測定は、ＦＣＣＪが公開しているプロトコルに記載してある「電位サイクル試験方法」を参考にし、よりカーボンの劣化現象が促進されるように最適化した条件にて実施した。０．１Ｍで調整した過塩素酸でガラスセルを満たし、６０℃に加温しながら、ガラスセル内に窒素を３０分間バブリングした。該過塩素酸を用いて、カーボン表面のクリーニングとＥＣＳＡの測定のため、０．０５～１．２０Ｖ　ｖｓ　ＲＨＥ、５０ｍＶ／ｓの条件で電極の回転数をゼロとしてＣＶを実施した。再現性のあるボルタモグラムが得られたら、１．５Ｖの高電位を１０時間負荷し、その後のボルタンメトリーから高電位負荷後のＥＣＳＡ（ｍ２／ｇＰｔ）を測定し、下記の式によりＥＣＳＡ維持率（％）を算出した。
　ＥＣＳＡ維持率（％）＝（高電位負荷後のＥＣＳＡ／ＥＣＳＡ（初期値））×１００
　耐久性の判定は、以下の基準で行った。
　＜判定基準＞
　◎：ＥＣＳＡ維持率が７０％以上である。
　○：ＥＣＳＡ維持率が５０％以上７０％未満である。
　×：ＥＣＳＡ維持率が５０％未満である。 (4) ECSA maintenance rate (index of durability and electrode life)
The ECSA retention rate was measured under the optimized conditions so as to further promote the deterioration phenomenon of carbon with reference to “potential cycle test method” described in the protocol published by FCCJ. The glass cell was filled with perchloric acid adjusted at 0.1 M, and nitrogen was bubbled into the glass cell for 30 minutes while heating to 60 ° C. Using the perchloric acid, CV was performed under the conditions of 0.05 to 1.20 V vs. RHE, 50 mV / s with the number of revolutions of the electrode being zero for cleaning the carbon surface and measuring ECSA. When a reproducible voltammogram was obtained, a high potential of 1.5 V was loaded for 10 hours, and ECSA (m 2 / gPt) after high potential loading was measured from the subsequent voltammetry, and the ECSA maintenance rate ( %) Was calculated.
ECSA maintenance rate (%) = (ECSA / ECSA (initial value) after high potential load) × 100
The durability was determined according to the following criteria.
<Criteria>
A: ECSA maintenance rate is 70% or more.
A: ECSA maintenance rate is 50% or more and less than 70%.
X: ECSA maintenance rate is less than 50%.
　各例の触媒担持用カーボンの物性の測定結果及び評価結果を表２に示す。 Table 2 shows the measurement results and evaluation results of the physical properties of the catalyst-supporting carbon in each example.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　表２に示すように、条件（ａ）～（ｄ）を満たす実施例１～７の触媒担持用カーボンは、ＥＳＣＡ（初期値）が高く、白金担持率が高く触媒の分散担持性に優れていた。また、実施例１～７の触媒担持用カーボンは、ＥＳＣＡ維持率が高く、耐久性（酸化分解耐性）にも優れていた。
　一方、条件（ｂ）及び（ｃ）を満たしていない比較例１では、ＥＳＣＡ（初期値）が著しく低く、白金担持率が低く触媒の分散担持性が劣っていた。条件（ａ）を満たしていない比較例２では、ＥＳＣＡ維持率がゼロであり、耐久性（酸化分解耐性）が著しく劣っていた。条件（ｄ）を満たしていない比較例３では、ＥＳＣＡ（初期値）が著しく低かった。 As shown in Table 2, the catalyst-supporting carbons of Examples 1 to 7 satisfying the conditions (a) to (d) have a high ESCA (initial value), a high platinum support rate, and excellent catalyst dispersion support. It was. Further, the catalyst-supporting carbons of Examples 1 to 7 had a high ESCA maintenance rate and excellent durability (oxidative decomposition resistance).
On the other hand, in Comparative Example 1 that did not satisfy the conditions (b) and (c), the ESCA (initial value) was remarkably low, the platinum support rate was low, and the dispersion support property of the catalyst was inferior. In Comparative Example 2 that did not satisfy the condition (a), the ESCA maintenance rate was zero, and the durability (oxidative degradation resistance) was remarkably inferior. In Comparative Example 3 that did not satisfy the condition (d), ESCA (initial value) was remarkably low.
［実施例８］
　白金担持カーボンの調製：
　実施例１の触媒担持用カーボン０．５ｇ、水２４０ｇ、エチレングリコール３２０ｇを超音波により混合した後、ヘキサクロリド白金（ＩＶ）酸六水和物１．３２ｇとエチレングリコール４０ｇの混合溶液に加え、１ｍｏｌ／Ｌ水酸化ナトリウム水溶液を添加してｐＨ１１に調整した。この溶液をフラスコに移し、窒素置換後、１１０℃で４時間撹拌した。冷却後、溶液をろ過し、ろ物をｐＨ７となるまで純水で洗浄し、１晩減圧乾燥して白金担持カーボンを得た。 [Example 8]
Preparation of platinum-supported carbon:
The catalyst-supporting carbon 0.5g of Example 1, 240 g of water, and 320 g of ethylene glycol were mixed by ultrasonic waves, and then added to a mixed solution of 1.32 g of hexachloride platinum (IV) acid hexahydrate and 40 g of ethylene glycol. A 1 mol / L sodium hydroxide aqueous solution was added to adjust the pH to 11. This solution was transferred to a flask, and purged with nitrogen, followed by stirring at 110 ° C. for 4 hours. After cooling, the solution was filtered, and the filtrate was washed with pure water until pH 7 and dried under reduced pressure overnight to obtain platinum-supported carbon.
　膜電極接合体（ＭＥＡ）の作製：
　白金担持カーボン２．０ｇ（白金担持率：５０質量％）、アイオノマーとして２０質量％　Ｎａｆｉｏｎ（商標登録）ＤＥ２０２１分散溶液（デュポン社製）２．０ｇ、アルコール水溶液１６．０ｇを秤量し、ビーズミルを用いて混合し、触媒インクを作成した。この触媒インクにおける触媒担持カーボンに対するアイオノマーの質量比は、アイオノマー／カーボン（Ｉ／Ｃ）＝０．４である。この触媒インクを、触媒量が０．３ｍｇ／ｃｍ２となるようにポリテトラフルオロエチレン（ＰＴＦＥ）シートに塗布、乾燥させ、５ｃｍ２の矩形状に切ってカソード電極を作製した。次に、カソード電極とアノード電極により電解質膜を挟み込み、ホットプレスを行ってＭＥＡを作製した。アノード電極には、ＴＥＣ１０Ｅ５０Ｅ（田中貴金属工業株式会社製）を用いた。 Production of membrane electrode assembly (MEA):
Weigh 2.0 g of platinum-supporting carbon (platinum support ratio: 50 mass%), 20 mass% as ionomer, 2.0 g of Nafion (registered trademark) DE2021 dispersion (manufactured by DuPont), and 16.0 g of aqueous alcohol solution, and use a bead mill. And mixed to prepare a catalyst ink. The mass ratio of ionomer to catalyst-supported carbon in this catalyst ink is ionomer / carbon (I / C) = 0.4. This catalyst ink was applied to a polytetrafluoroethylene (PTFE) sheet so that the amount of catalyst was 0.3 mg / cm 2 , dried, and cut into a rectangular shape of 5 cm 2 to produce a cathode electrode. Next, the electrolyte membrane was sandwiched between the cathode electrode and the anode electrode, and hot pressing was performed to produce an MEA. TEC10E50E (manufactured by Tanaka Kikinzoku Kogyo Co., Ltd.) was used for the anode electrode.
［実施例９］
　実施例２の触媒担持用カーボンを用いた以外は実施例８と同様にして白金担持カーボンを調製し、ＭＥＡを作製した。 [Example 9]
A platinum-supporting carbon was prepared in the same manner as in Example 8 except that the catalyst-supporting carbon of Example 2 was used, and an MEA was prepared.
［実施例１０］
　実施例８と同様にして白金担持カーボンを調製し、Ｉ／Ｃ＝０．７とした以外は実施例８と同様にしてＭＥＡを作製した。 [Example 10]
A platinum-supporting carbon was prepared in the same manner as in Example 8, and an MEA was prepared in the same manner as in Example 8 except that I / C = 0.7.
［実施例１１］
　実施例２の触媒担持用カーボンを用いた以外は実施例８と同様にして白金担持カーボンを調製し、Ｉ／Ｃ＝０．７とした以外は実施例８と同様にしてＭＥＡを作製した。 [Example 11]
A platinum-supporting carbon was prepared in the same manner as in Example 8 except that the catalyst-supporting carbon of Example 2 was used, and an MEA was prepared in the same manner as in Example 8 except that I / C = 0.7.
［比較例４］
　比較例１の触媒担持用カーボンを用いた以外は実施例８と同様にして白金担持カーボンを調製し、Ｉ／Ｃ＝０．７とした以外は実施例８と同様にしてＭＥＡを作製した。 [Comparative Example 4]
A platinum-supporting carbon was prepared in the same manner as in Example 8 except that the catalyst-supporting carbon of Comparative Example 1 was used, and an MEA was prepared in the same manner as in Example 8 except that I / C = 0.7.
［比較例５］
　比較例２の触媒担持用カーボンを用いた以外は実施例８と同様にして白金担持カーボンを調製し、Ｉ／Ｃ＝１．０とした以外は実施例８と同様にしてＭＥＡを作製した。 [Comparative Example 5]
A platinum-supporting carbon was prepared in the same manner as in Example 8 except that the catalyst-supporting carbon of Comparative Example 2 was used, and an MEA was prepared in the same manner as in Example 8 except that I / C = 1.0.
［比較例６］
　比較例２の触媒担持用カーボンを用いた以外は実施例８と同様にして白金担持カーボンを調製し、Ｉ／Ｃ＝０．７とした以外は実施例８と同様にしてＭＥＡを作製した。 [Comparative Example 6]
A platinum-supporting carbon was prepared in the same manner as in Example 8 except that the catalyst-supporting carbon of Comparative Example 2 was used, and an MEA was prepared in the same manner as in Example 8 except that I / C = 0.7.
［ＭＥＡの評価］
　（初期性能評価）
　ＭＥＡを温度８０℃、湿度９０％ＲＨの条件で加湿し、アノード電極に水素を５００ｓｃｃｍで供給し、カソード電極に酸素を５００ｓｃｃｍで供給してＩ－Ｖ測定を行った。性能は０．６Ｖにおける電流密度（Ａ／ｃｍ２）で比較した。 [Evaluation of MEA]
(Initial performance evaluation)
The MEA was humidified under conditions of a temperature of 80 ° C. and a humidity of 90% RH, hydrogen was supplied to the anode electrode at 500 sccm, and oxygen was supplied to the cathode electrode at 500 sccm to perform IV measurement. The performance was compared by the current density (A / cm 2 ) at 0.6V.
　（耐久性能評価）
　ＦＣＣＪが公開している「固体高分子形燃料電池の目標・研究開発課題と評価方法の提案」に記載の電位サイクル（起動停止）試験に従って耐久性能を評価した。ＭＥＡを温度８０℃、湿度９０％ＲＨの条件で加湿し、アノード電極に水素を５００ｓｃｃｍで供給し、カソード電極に酸素を５００ｓｃｃｍで供給してＩ－Ｖ測定を行った。１．０Ｖで３０秒間電位を保持した後、電圧範囲１．０Ｖ～１．５Ｖ、電位走査速度０．５Ｖ／ｓで５，０００サイクルの電位サイクル試験を行った後、Ｉ－Ｖ測定を行った。電位サイクル試験前後のＩ－Ｖ測定の０．６Ｖにおける電流密度（Ａ／ｃｍ２）から、下式により電流密度維持率を算出した。
　電流密度維持率（％）＝Ｊ５０００／Ｊ０×１００
　ただし、Ｊ０は電位サイクル試験前のＩ－Ｖ測定の０．６Ｖにおける電流密度（Ａ／ｃｍ２）であり、Ｊ５０００は５，０００サイクルの電位サイクル試験を行った後のＩ－Ｖ測定の０．６Ｖにおける電流密度（Ａ／ｃｍ２）である。 (Durability performance evaluation)
Durability performance was evaluated according to the potential cycle (start / stop) test described in FCCJ's published “Proposals for Targets, R & D Issues and Evaluation Methods for Polymer Electrolyte Fuel Cells”. The MEA was humidified under conditions of a temperature of 80 ° C. and a humidity of 90% RH, hydrogen was supplied to the anode electrode at 500 sccm, and oxygen was supplied to the cathode electrode at 500 sccm to perform IV measurement. After holding the potential at 1.0 V for 30 seconds, after conducting a potential cycle test of 5,000 cycles at a voltage range of 1.0 V to 1.5 V and a potential scanning speed of 0.5 V / s, an IV measurement was performed. It was. From the current density (A / cm 2 ) at 0.6 V in the IV measurement before and after the potential cycle test, the current density maintenance ratio was calculated by the following equation.
Current density maintenance ratio (%) = J 5000 / J 0 × 100
However, J 0 is the current density (A / cm 2 ) at 0.6 V of the IV measurement before the potential cycle test, and J 5000 is the IV measurement after conducting the potential cycle test of 5,000 cycles. Current density (A / cm 2 ) at 0.6V.
　実施例８～１１、比較例４～６のＭＥＡの初期性能及び耐久性能の評価結果を表３に示す。 Table 3 shows the evaluation results of the initial performance and durability performance of the MEAs of Examples 8 to 11 and Comparative Examples 4 to 6.
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
　表３に示すように、本発明の触媒担持用カーボンを用いた実施例８～１１では、ＭＥＡの電流密度が高く、初期性能が優れていた。また、実施例１０、１１では５，０００サイクルの電位サイクル試験後もＭＥＡは高い電流密度を維持しており、耐久性能にも優れていた。 As shown in Table 3, in Examples 8 to 11 using the catalyst-supporting carbon of the present invention, the MEA current density was high and the initial performance was excellent. In Examples 10 and 11, the MEA maintained a high current density even after 5,000 cycles of the potential cycle test, and was excellent in durability.

Claims (2)

  1. 　下記条件（ａ）～（ｄ）を満たす触媒担持用カーボン。
    　（ａ）広角Ｘ線回折法による測定結果から算出されるカーボン表面の結晶子の厚みＬｃ（００２）が２．０ｎｍ以上である。
    　（ｂ）ラマン分光法によるカーボン表面のスペクトルにおけるＧ－ｂａｎｄ（１５９０ｃｍ－１）のピーク面積に対するＤ１－ｂａｎｄ（１３５０ｃｍ－１）のピーク面積の比Ｄ／Ｇが０．５～２．５である。
    　（ｃ）メソ孔を含む細孔を有し、メソ孔容積が０．３５～１．３ｃｍ３／ｇである。
    　（ｄ）全細孔容積に対する前記メソ孔容積の比率が０．６～１．０である。     Catalyst-supporting carbon that satisfies the following conditions (a) to (d).
    (A) The crystallite thickness Lc (002) of the carbon surface calculated from the measurement result by the wide-angle X-ray diffraction method is 2.0 nm or more.
    (B) at D 1 -band (1350cm -1) ratio D / G is 0.5 of the peak area of 2.5 to the peak area of G-band of the spectrum of the carbon surface by Raman spectroscopy (1590 cm -1) is there.
    (C) It has pores including mesopores, and the mesopore volume is 0.35 to 1.3 cm 3 / g.
    (D) The ratio of the mesopore volume to the total pore volume is 0.6 to 1.0.
  2. 　請求項１に記載の触媒担持用カーボンを製造する方法であって、
    　カーボンブラックを２２００℃以上で熱処理して炭素材料を得る熱処理工程と、
    　前記熱処理工程後の炭素材料に対して表面酸化処理を行う表面酸化工程と、
    　を有する、触媒担持用カーボンの製造方法。     A method for producing the catalyst-supporting carbon according to claim 1,
    A heat treatment step of obtaining a carbon material by heat treating carbon black at 2200 ° C. or higher;
    A surface oxidation step of performing a surface oxidation treatment on the carbon material after the heat treatment step;
    A method for producing catalyst-supporting carbon, comprising:
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