JP2009231158A - Electrode catalyst layer for fuel cell, membrane electrode assembly, the fuel cell, and manufacturing method of the electrode catalyst layer for fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrode catalyst layer for fuel cell with high durability, which shows high power-generation performance, and to provide a membrane electrode assembly, a fuel cell, and a manufacturing method of electrode catalyst layer for fuel cell. <P>SOLUTION: The electrode catalyst layer for fuel cell contains a polymer electrolyte, a carrier carrying a catalyst material, and an amorphous carbon introduced sulfonic acid group. If the total weight of the weight of the amorphous carbon introduced sulfonic acid group (A) and the weight of only carrier (B) is defined as (X), the weight ratio (Y/X) of (X) to the polymer electrolyte Y is 0.8 or larger and 3.0 or smaller, and (A) contains 0.1% or higher and 30% or lower by the weight ratio to (B). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fuel cell electrode catalyst layer, a membrane electrode assembly, a fuel cell, and a method for producing a fuel cell electrode catalyst layer. More specifically, by containing amorphous carbon introduced with a sulfonic acid group, under high humidification conditions, flooding is suppressed, and a fuel cell electrode catalyst layer exhibiting high power generation characteristics, a membrane electrode assembly, The present invention relates to a fuel cell and a method for producing a fuel cell electrode catalyst layer.

  A fuel cell is a power generation system that generates electricity by using hydrogen and oxygen as fuel and causing reverse reaction of water electrolysis. This has features such as high efficiency, low environmental load and low noise compared with the conventional power generation method, and is attracting attention as a clean energy source in the future. Fuel cells can be classified according to their electrolyte, and include molten carbonate fuel cells, phosphoric acid fuel cells, solid oxide fuel cells, solid polymer fuel cells, and the like.

  Among the fuel cells, the polymer electrolyte fuel cell can be operated in a low temperature region, and is generally used at an operating temperature of 80 ° C. to 100 ° C., such as an in-vehicle power source or a household stationary power source. Promising use. A polymer electrolyte fuel cell supplies a joined body in which a pair of electrodes are arranged on both sides of a polymer electrolyte membrane called MEA (electrolyte membrane electrode assembly), and a fuel gas containing hydrogen is supplied to one of the electrodes, The battery is sandwiched between a pair of separator plates in which a gas channel for supplying an oxidant gas containing oxygen to the other electrode is formed. Here, the electrode for supplying the fuel gas is called a fuel electrode, and the electrode for supplying the oxidant is called an air electrode. The above-mentioned electrode is a joined body composed of an electrode catalyst layer formed by laminating carbon particles supporting a catalyst material such as a platinum-based noble metal and a polymer electrolyte, and a gas diffusion layer having both gas permeability and conductivity. is there.

  In the polymer electrolyte fuel cell, in order to ensure the conductivity of the electrolyte membrane, the humidified gas is supplied to the MEA by using the MEA as an auxiliary device. In addition, as power is generated, protons dissociated at the fuel electrode pass through the electrolyte membrane, and water is generated at the electrode catalyst layer on the air electrode side. If the generated water has poor drainage, flooding occurs and power generation performance is significantly reduced. Further, when water generated at the air electrode is back-diffused and moves to the fuel electrode, the same problem occurs at the fuel electrode.

  In order to solve the above problems, Patent Document 1 discloses a technique in which porous hydrophilic fibers are provided in an electrode catalyst layer to suppress flooding (see Patent Document 1).

However, providing the fibrous material in the catalyst layer is concerned that the fibers may pierce the electrolyte membrane, and problems such as cross leakage and short circuit between the fuel electrode and the air electrode occur. The thinner the electrolyte membrane itself, the more serious the above problem.
JP 2007-328936 A

  An object of the present invention is to provide a fuel cell electrode catalyst layer, a membrane electrode assembly, a fuel cell, and a method for producing a fuel cell electrode catalyst layer having high durability and high power generation performance.

  As a result of intensive studies, the present inventor has been able to solve the above-mentioned problems and has completed the present invention.

  The invention according to claim 1 of the present invention comprises a polymer electrolyte, a carrier carrying a catalyst substance, and amorphous carbon having a sulfonic acid group introduced therein, and having an amorphous carbon having a sulfonic acid group introduced therein. The weight ratio (Y / X) with respect to the polymer electrolyte Y is 0.8 or more and 3.0 or less, when the combined weight (A) and the weight (B) of the carrier alone is (X). In addition, (A) is a fuel cell electrode catalyst layer characterized by containing 0.1% to 30% by weight with respect to (B).

The invention according to claim 2 of the present invention relates to a condensed aromatic carbon 6 in which a condensed aromatic carbon 6-membered ring and a sulfonic acid group are bonded to each other in a ¹³ C nuclear magnetic resonance spectrum of amorphous carbon to which a sulfonic acid group is introduced. A chemical shift of a member ring is detected, and a diffraction peak of a carbon (002) plane having a half width (2θ) of 5 ° or more and 30 ° or less is detected by powder X-ray diffraction. The electrode catalyst layer for a fuel cell according to claim 1 is used.

  The invention according to claim 3 of the present invention is the electrode for a fuel cell according to claim 1, wherein only the diffraction peak of the carbon (002) plane is detected in powder X-ray diffraction of amorphous carbon into which a sulfonic acid group has been introduced. This is a catalyst layer.

  In the invention according to claim 4 of the present invention, the sulfonic acid density of the amorphous carbon into which the sulfonic acid group is introduced is 2 mmol / g or more and 12 mmol / g or less. This is a fuel cell electrode catalyst layer.

  The invention according to claim 5 of the present invention is a membrane electrode assembly comprising the fuel cell electrode catalyst layer according to any one of claims 1 to 4.

  An invention according to claim 6 of the present invention is a fuel cell comprising the fuel cell electrode catalyst layer according to any one of claims 1 to 4.

  In the invention according to claim 7 of the present invention, the carrier carrying the catalyst substance is used in the amorphous carbon solvent into which the sulfonic acid group is introduced, and the weight (A) of the amorphous carbon having the sulfonic acid group introduced therein and the carrier. Only (B) is dispersed in a weight ratio of 0.1% to 30% with respect to (B), and the dispersion-supported carrier and polymer electrolyte are treated with sulfone. The weight ratio (Y / X) with respect to the polymer electrolyte Y is (X) where the combined weight (A) of the amorphous carbon introduced with acid groups and the weight (B) of the carrier alone is (X). A method for producing an electrode catalyst layer for a fuel cell, characterized in that mixing is performed so that the amount is 0.8 or more and 3.0 or less.

The invention according to claim 8 of the present invention relates to a condensed aromatic carbon 6 in which a condensed aromatic carbon 6-membered ring and a sulfonic acid group are bonded to each other in a ¹³ C nuclear magnetic resonance spectrum of amorphous carbon into which a sulfonic acid group is introduced. A chemical shift of a member ring is detected, and a diffraction peak of a carbon (002) plane having a half width (2θ) of 5 ° or more and 30 ° or less is detected by powder X-ray diffraction. The method for producing an electrode catalyst layer for a fuel cell according to claim 7.

  The invention according to claim 9 of the present invention is the electrode for a fuel cell according to claim 7, wherein only the diffraction peak of the carbon (002) plane is detected in powder X-ray diffraction of amorphous carbon into which a sulfonic acid group has been introduced. This is a method for producing a catalyst layer.

  The invention according to claim 10 of the present invention is the amorphous carbon having a sulfonic acid group introduced therein, wherein the sulfonic acid density is 2 mmol / g or more and 12 mmol / g or less. This is a method for producing an electrode catalyst layer for a fuel cell.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the electrode catalyst layer for fuel cells which shows high durability and high electric power generation performance, a membrane electrode assembly, a fuel cell, and the electrode catalyst layer for fuel cells can be provided.

  Hereinafter, the present invention is not limited to each embodiment, and various modifications such as design changes can be added based on the knowledge of those skilled in the art. The form can also be included in the technical scope of the present invention.

  In the fuel cell electrode catalyst layer according to the embodiment of the present invention, the amorphous carbon into which the sulfonic acid group is introduced may be any material having a sulfonic acid group and exhibiting properties as amorphous carbon. But it ’s okay.

  Here, “amorphous carbon” is a substance composed of carbon and does not have a clear crystal structure such as diamond or graphite, and more specifically, a clear peak in powder X-ray diffraction. Means a substance in which no or a broad peak is detected.

  For the electrode catalyst layer for a fuel cell according to the embodiment of the present invention, a substance obtained by chemically treating the surface of amorphous carbon into which a sulfonic acid group has been introduced can also be suitably used.

  When the catalyst layer containing amorphous carbon having a sulfonic acid group introduced is used as a polymer electrolyte, for example, Nafion (registered trademark), the affinity with the hydrophilic side chain of Nafion is improved. Power generation performance can be improved.

  The proton conductivity of the sulfonic acid group-introduced amorphous carbon is not particularly limited, but is preferably 0.01 S / cm or more, and particularly preferably 0.04 S / cm or more.

  If the proton conductivity of amorphous carbon is 0.01 S / cm or more, protons generated inside the carbon can be efficiently conducted. (Proton conductivity is a value measured by the AC impedance method under conditions of a temperature of 80 ° C. and a relative humidity of 100%.)

The electrode catalyst layer for a fuel cell according to the embodiment of the present invention has a condensed aromatic carbon 6-membered ring and a sulfonic acid group bonded to each other in a ¹³ C nuclear magnetic resonance spectrum of amorphous carbon into which a sulfonic acid group has been introduced. A chemical shift of a fused aromatic carbon 6-membered ring is detected, and a diffraction peak of a carbon (002) plane having a half-value width (2θ) of 5 ° to 30 ° is detected by powder X-ray diffraction. Is preferred. Amorphous carbon into which a sulfonic acid group has been introduced is π-π stacked by carbon of platinum-catalyzed carbon and its condensed aromatic carbon 6-membered ring, can prevent aggregation, and can efficiently conduct protons. .

  It is preferable that only the diffraction peak of the carbon (002) plane is detected in the powder X-ray diffraction of amorphous carbon into which a sulfonic acid group has been introduced. When amorphous carbon having a highly purified sulfonic acid group is used, protons can be conducted more efficiently.

  The sulfonic acid density of the amorphous carbon into which the sulfonic acid group is introduced according to the embodiment of the present invention is preferably 2 mmol / g or more and 12 mmol / g or less in order to improve the power generation characteristics. When the sulfonic acid density is less than 2 mmol / g, the proton conductivity is lowered, and when the sulfonic acid density exceeds 12 mmol / g, the yield in the synthesis of amorphous carbon itself into which sulfonic acid groups are introduced is deteriorated. End up.

  The electrolyte membrane according to the embodiment of the present invention is not particularly limited as long as it is made of a material that is excellent in proton conductivity and does not flow electrons. In particular, a perfluoro type sulfonic acid membrane, for example, a membrane of Nafion (registered trademark), Flemion (registered trademark), Aciplex (registered trademark) or the like is used.

  As the electrolyte membrane, a composite membrane excellent in heat resistance and methanol crossover prevention using an inorganic compound as a proton conducting material and a polymer as a membrane material, for example, using zeolite as the inorganic compound and styrene-butadiene as the polymer A composite film made of rubber, a hydrocarbon resin such as polyimide having a proton conductive group, or a hydrocarbon graft film may be used.

  The catalyst which concerns on embodiment of this invention can use what is generally used, and is not specifically limited. Specifically, the platinum-supported carbon platinum may be carbon particles carrying a platinum simple substance or a platinum alloy. Examples of the alloy include palladium, ruthenium, and molybdenum, and ruthenium is particularly desirable. Moreover, tungsten, tin, rhenium, etc. may be contained as an additive in the platinum alloy. When the additive is contained, the poisoning resistance of CO (carbon monoxide) increases. The additive metal may exist as a platinum alloy intermetallic compound or may form an alloy. Moreover, these catalyst particle diameters are preferably 0.5 nm or more and 20 nm or less. More preferably, it is 1 nm or more and 5 nm or less. When the catalyst particle size is larger than 20 nm, the activity of the catalyst is lowered, and when the catalyst particle size is smaller than 0.5 nm, the stability of the catalyst is lowered. The catalyst loading is preferably 40% by weight or more and 60% by weight or less. If the catalyst loading is less than 40% by weight, the fuel cell thickness is increased due to the increase in the thickness of the fuel cell, and if the catalyst loading exceeds 60% by weight, the dispersibility of the catalyst is deteriorated.

  Various proton conductive polymers are used in the catalyst ink according to the embodiment of the present invention, and it is necessary to select the proton conductive polymer in the ink depending on the components of the electrolyte membrane to be used. is there. When Nafion is used as the electrolyte membrane, it is preferable to use Nafion. When a material other than Nafion is used for the electrolyte membrane, it is necessary to optimize such as dissolving the same components as the electrolyte membrane in the ink.

  The solvent used as the dispersion medium of the catalyst ink according to the embodiment of the present invention does not erode the catalyst particles or the hydrogen ion conductive resin, and dissolves or finely dissolves the proton conductive polymer in a highly fluid state. There is no particular limitation as long as it can be dispersed as a gel, but it is desirable to include an emissive liquid organic solvent, and although not particularly limited, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol , 2-butanol, isobutyl alcohol, tert-butyl alcohol, pentanol, 2-heptanol, benzyl alcohol, and other alcohols, acetone, methyl ethyl ketone, methyl propyl ketone, methyl butyl ketone, methyl isobutyl ketone, methyl amyl ketone, pentanone, Heptanone, cyclohexanone, methyl Ketones such as cyclohexanone, acetonyl acetone, diethyl ketone, dipropyl ketone, diisobutyl ketone, tetrahydrofuran, tetrahydropyran, dioxane, diethylene glycol dimethyl ether, anisole, methoxytoluene, diethyl ether, dipropyl ether, dibutyl ether and other ethers, isopropyl Amines such as amine, butylamine, isobutylamine, cyclohexylamine, diethylamine, aniline, propyl formate, isobutyl formate, amyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, isobutyl acetate, pentyl acetate, isopentyl acetate, propionic acid Esters such as methyl, ethyl propionate and butyl propionate, other acetic acid, propionic acid, dimethylform Use polar solvents such as amide, dimethylacetamide, N-methylpyrrolidone, ethylene glycol, diethylene glycol, propylene glycol, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diacetone alcohol, 1-methoxy-2-propanol Is done. Moreover, what mixed 2 or more types of these solvents can also be used.

  By using two types of solvents having different dielectric constants among the solvents, the dispersion state of the proton conductive polymer in the dispersion can be controlled. These solvents and those using lower alcohols as the solvent have a high risk of ignition, and when using such a solvent, it is preferable to use a mixed solvent with water. Water that is compatible with the hydrogen ion conductive resin may be contained. The amount of water added is not particularly limited as long as the proton conductive polymer is not separated to cause white turbidity or gelation. In order to control the porosity of the catalyst layer after film formation, glycerin or a surfactant can be added as a pore-forming agent.

  The weight ratio (Y / X) to the polymer electrolyte Y is (X) where the weight (A) of the amorphous carbon having the sulfonic acid group introduced and the weight (B) of the carrier alone are combined (X). 0.8 or more and 3.0 or less are preferable. When the weight ratio (Y / X) is lower than 0.8, the amount in the polymer electrolyte in the catalyst layer is small, the path of protons moving through the catalyst layer is cut, and proton conductivity is lowered. For this reason, it is desirable to increase the amount of the polymer electrolyte as much as possible. However, if the amount of the polymer electrolyte is increased too much, the drainage performance of water decreases and flooding occurs. By containing amorphous carbon (A) having a sulfonic acid group introduced therein in a weight ratio of 0.1% to 30% with respect to the support (B), flooding can be suppressed. If the weight ratio (Y / X) exceeds 3.0, even if amorphous carbon is added, the amount of polymer electrolysis is too large and flooding occurs.

  As a method for forming the catalyst layer, a doctor blade method, a dipping method, a screen printing method, a roll coating method, a spray method or the like is generally used.

  The optimum value of the viscosity of the catalyst ink varies depending on the coating method. For example, in the case of application by a screen printing method or a doctor blade method, the viscosity of the ink is preferably 50 cP or more and 500 cP or less. Whether the viscosity is higher or lower than this range of viscosity makes it difficult to apply ink. On the other hand, when spraying on a base material by a spray method, it is preferable that the viscosity of an ink is 0.1 cP or more and 100 cP or less. If the viscosity of the ink is higher than 100 cP, spraying becomes difficult, and if the viscosity of the ink is lower than 0.1 cP, the film forming rate is very slow and the productivity is lowered. The ink viscosity is optimized by changing the type of solvent and solid content concentration. Further, the viscosity can be controlled by adding a dispersing agent when the ink is dispersed.

  In the method for producing an electrode catalyst layer for a fuel cell according to an embodiment of the present invention, an ink is sprayed on a gas diffusion layer and dried, and the proton conductive polymer membrane and the catalyst layer are joined by thermocompression bonding. A method of spraying ink directly on both sides of a proton conductive polymer membrane and sandwiching this between gas diffusion layers, or spraying ink on a releasable substrate and then using it as a proton conductive polymer There is no problem even if a method of sandwiching the material transferred on both sides of the film with a gas diffusion layer is used.

  As shown in FIG. 1, a membrane electrode assembly 12 according to an embodiment of the present invention is sandwiched between an electrode catalyst layer 2 and an electrode catalyst layer 3 on both surfaces of a solid polymer electrolyte 1. Since description about the solid polymer electrolyte 1, the electrode catalyst layer 2, and the electrode catalyst layer 3 was mentioned above, it abbreviate | omits.

  As shown in FIG. 2, the polymer electrolyte fuel cell 20 according to the embodiment of the present invention includes an air electrode side gas diffusion layer 4 facing the electrode catalyst layer 2 and the electrode catalyst layer 3 of the membrane electrode assembly 12. The fuel electrode side gas diffusion layer 5 is disposed. Thereby, the air electrode 6 and the fuel electrode 7 are comprised, respectively. Then, a set of separators 10 made of a conductive and impermeable material, which is provided with a gas flow path 8 for gas flow and is provided with a cooling water flow path 9 for cooling water flow on the opposing main surface, is disposed. For example, hydrogen gas is supplied as a fuel gas from the gas flow path 8 of the separator 10 on the fuel electrode 7 side. On the other hand, a gas containing oxygen, for example, is supplied as an oxidant gas from the gas flow path 8 of the separator 10 on the air electrode 6 side.

  As shown in FIG. 2, a solid polymer fuel cell 20 according to an embodiment of the present invention includes a set of separators 10 and a solid polymer electrolyte membrane 1, an electrode catalyst layer 2, an electrode catalyst layer 3, and a gas diffusion layer. 4. The gas diffusion layer 5 is sandwiched. This is a solid polymer fuel cell 20 having a so-called single cell structure.

  As the gas diffusion layer 4, the gas diffusion layer 5, and the separator 10 according to the embodiment of the present invention, those used in the fuel cell can be used. Specifically, porous carbon materials such as carbon cloth, carbon paper, and nonwoven fabric are used for the gas diffusion layer 4 and the gas diffusion layer 5. As the separator 10, a carbon type metal type or the like can be used.

  A membrane electrode assembly 12 can be obtained by thermocompression bonding the catalyst electrode to a polymer electrolyte membrane 1 such as Nafion or sulfonated engineering plastic with a press or the like. 10 and auxiliary devices (such as a gas supply device and a cooling device) are assembled and united or stacked to produce a fuel cell.

  When the electrode catalyst layer 2, the electrode catalyst layer 3 and the polymer electrolyte membrane 1 are joined, thermocompression bonding can be performed. Furthermore, it is preferable to apply a solution containing a proton conductive polymer as a binder between the electrode catalyst layer 2 and the electrode catalyst layer 3 and the proton conductive polymer in order to improve the bonding property. The same material as that of the conductive polymer electrolyte membrane 1 is preferable.

  The polymer electrolyte fuel cell 20 according to the embodiment of the present invention includes the electrode catalyst layer 4 and the electrode catalyst layer 5 according to the embodiment of the present invention to suppress flooding under highly humid conditions. In addition, high power generation characteristics can be exhibited.

  Specific examples and comparative examples are shown below to explain the present invention, but the present invention is not limited to the examples.

[Synthesis of amorphous carbon with sulfonic acid group]
Naphthalene was added to concentrated sulfuric acid (96%) and heated at 250 ° C. for 15 hours, and then excess concentrated sulfuric acid was removed by vacuum distillation at 250 ° C. to obtain a black powder. This black powder was washed with 300 ml of distilled water, and this operation was repeated until the sulfuric acid in the distilled water after washing was below the detection limit of elemental analysis to obtain sulfonic acid group-introduced amorphous carbon. The sulfonic acid density was 2.4 mmol / g. This compound was sieved to take out a compound having a good dispersibility of 15 nm in water. The degree of dispersion was measured with a Nanotrac particle size analyzer UPA-EX manufactured by Nikkiso Co., Ltd., and the value was obtained as the value of the number average diameter.

[Adjustment of catalyst ink]
Ketjen black (Tanaka Kikinzoku Kogyo Co., Ltd.) carrying a platinum catalyst. Here, the weight of only Ketjen black was (B). Perfluorocarbon sulfonic acid (Y) represented by the trade name “Nafion (registered trademark) solution” manufactured by Du Pont, and amorphous carbon (A) having a sulfonic acid group introduced therein are mixed in a solvent and dispersed. Processed.

  Amorphous carbon (A) into which sulfonic acid groups have been introduced is added at 5% by weight with respect to ketjen black (B), and the polymer electrolyte is mixed at a ratio of 0 (Y / X) = 1.2. did. (X = A + B)

[Method for producing electrode catalyst layer]
An electrode catalyst layer was prepared by applying the dispersion-treated catalyst ink using an applicator. The thickness of the electrode catalyst layer was adjusted so that the amount of catalyst supported on the electrode catalyst layer was 0.3 mg / cm ² .

[Comparative Example 1]
A catalyst ink was prepared in the same manner as in Example 1 except that amorphous carbon having a sulfonic acid group introduced was not used, and an electrode catalyst layer was prepared.

[Production of membrane electrode assembly]
After sandwiching the proton conductive polymer membrane represented by the trade name “Nafion (registered trademark) 212” manufactured by Du Pont with the catalyst electrode of Example 1 and Comparative Example 1, the temperature was 140 ° C. and the pressure was 5 MPa. Was subjected to hot pressing to obtain a membrane electrode assembly (MEA).

[Production of polymer electrolyte fuel cell]
A membrane electrode assembly (MEA) was sandwiched between a pair of calcined carbon separators to produce a polymer electrolyte fuel cell.

[Evaluation of power generation characteristics]
The power generation characteristics were evaluated using a fuel cell measuring device displayed by Toyo Technica Co., Ltd. under the trade name “GFT-SG1”. Hydrogen gas was used as the fuel, air was used as the oxidant, the cell temperature was 80 ° C., and the cell voltage value at each current density was evaluated.

FIG. 3 shows the results of power generation characteristics of the polymer electrolyte fuel cells produced using the electrode catalyst layers of Example 1 and Comparative Example 1. Current density ^{0.5A / cm 2, 0.8A / cm} 2, is a graph showing a cell voltage value at 1.0A / cm ^2. In Comparative Example 1, a voltage drop suddenly occurs at 1.0 A / cm ² due to flooding. That is, it was confirmed that the cell voltage of Example 1 was higher than that of Comparative Example 1 and the anti-flooding performance was improved.

  INDUSTRIAL APPLICABILITY The present invention can be used for a polymer electrolyte fuel cell used for an electric vehicle, a mobile phone, a vending machine, an underwater robot, a submarine, a spacecraft, an underwater vehicle, a power source for an underwater base, and the like.

It is a schematic sectional drawing which shows the membrane electrode assembly which concerns on embodiment of this invention. 1 is a schematic cross-sectional view showing a polymer electrolyte fuel cell according to an embodiment of the present invention. It is a figure which shows the electric power generation characteristic of the polymer electrolyte fuel cell which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Solid polymer electrolyte membrane 2 Electrode catalyst layer 3 Electrode catalyst layer 4 Gas diffusion layer 5 Gas diffusion layer 6 Air electrode 7 Fuel electrode 8 Gas flow path 9 Cooling water flow path 10 Separator 12 Membrane electrode assembly 20 Solid polymer fuel cell

Claims (10)

A polymer electrolyte;
A carrier carrying a catalyst material;
An amorphous carbon having a sulfonic acid group introduced therein,
When the combined weight of the amorphous carbon introduced with the sulfonic acid group (A) and the weight of the carrier alone (B) is (X), the weight ratio to the polymer electrolyte Y ( Y / X) is 0.8 or more and 3.0 or less, and (A) contains 0.1% or more and 30% or less by weight with respect to (B). . In the ¹³ C nuclear magnetic resonance spectrum of the amorphous carbon to which the sulfonic acid group is introduced, a chemical shift of the condensed aromatic carbon 6-membered ring and the condensed aromatic carbon 6-membered ring to which the sulfonic acid group is bonded is detected, and 2. The electrode for a fuel cell according to claim 1, wherein a diffraction peak of a carbon (002) surface having a half width (2θ) of 5 ° or more and 30 ° or less is detected by powder X-ray diffraction. Catalyst layer.   2. The electrode catalyst layer for a fuel cell according to claim 1, wherein only a diffraction peak on the carbon (002) plane is detected in powder X-ray diffraction of amorphous carbon into which the sulfonic acid group has been introduced.   4. The fuel cell electrode catalyst layer according to claim 1, wherein the amorphous carbon into which the sulfonic acid group is introduced has a sulfonic acid density of 2 mmol / g or more and 12 mmol / g or less. 5.   A membrane electrode assembly comprising the fuel cell electrode catalyst layer according to any one of claims 1 to 4.   A fuel cell comprising the fuel cell electrode catalyst layer according to any one of claims 1 to 4. The carrier carrying the catalyst substance is measured in an amorphous carbon solvent into which a sulfonic acid group has been introduced. The weight of the amorphous carbon into which the sulfonic acid group has been introduced (A) and the weight of the carrier alone (B). , (A) is subjected to a dispersion treatment so that the weight ratio is 0.1% or more and 30% or less with respect to (B),
The weight of the amorphous carbon into which the sulfonic acid group was introduced (A) and the weight of the carrier alone (B) were combined (X) with the dispersion-treated carrier and the polymer electrolyte. And mixing so that a weight ratio (Y / X) with the polymer electrolyte Y is 0.8 or more and 3.0 or less. In the ¹³ C nuclear magnetic resonance spectrum of the amorphous carbon to which the sulfonic acid group is introduced, a chemical shift of the condensed aromatic carbon 6-membered ring and the condensed aromatic carbon 6-membered ring to which the sulfonic acid group is bonded is detected, and 8. The electrode for a fuel cell according to claim 7, wherein a diffraction peak of a carbon (002) plane having a half width (2θ) of 5 ° to 30 ° is detected by powder X-ray diffraction. A method for producing a catalyst layer.   The method for producing an electrode catalyst layer for a fuel cell according to claim 7, wherein only the diffraction peak of the carbon (002) plane is detected in powder X-ray diffraction of amorphous carbon into which the sulfonic acid group has been introduced.   The method for producing an electrode catalyst layer for a fuel cell according to any one of claims 7 to 9, wherein the amorphous carbon having the sulfonic acid group introduced therein has a sulfonic acid density of 2 mmol / g or more and 12 mmol / g or less.

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