JP2012216313A - Catalyst layer for fuel cell, catalyst layer for fuel cell provided with substrate using the same, gas diffusion electrode for fuel cell, laminate of catalyst layer for fuel cell and electrolyte membrane, membrane electrode assembly for fuel cell, fuel cell and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a catalyst layer for a fuel cell which shows superior power generation performance at a high temperature and in a non-humidified state; the catalyst layer for the fuel cell provided with a substrate using the same; a gas diffusion electrode for a fuel cell; a laminate of the catalyst layer for the fuel cell and an electrolyte membrane; a membrane electrode assembly for a fuel cell; a fuel cell; and a method for producing the same.SOLUTION: The catalyst layer 2 for the fuel cell is the catalyst layer 2 for the fuel cell containing an electrolyte and a catalysis. The electrolyte contains an ionic liquid, a solid acid and phosphoric acids. In addition, the catalyst layer 2 for the fuel cell is produced by using a composition for forming a catalyst layer, which contains a solid acid, an ionic liquid, phosphoric acids and a catalysis, or is produced by applying one or more electrolytes selected from the group consisting of an ionic liquid and phosphoric acids to a catalyst layer formed by using the composition for forming the catalyst layer when the composition for forming the catalyst layer does not contain one or more electrolytes selected from the group consisting of an ionic liquid and phosphoric acids.

Description

  The present invention relates to a catalyst layer for a fuel cell, a catalyst layer for a fuel cell with a base material using the same, a gas diffusion electrode for a fuel cell, a catalyst layer-electrolyte membrane laminate for a fuel cell, a membrane electrode assembly for a fuel cell, and The present invention relates to a fuel cell and a manufacturing method thereof.

In recent years, with increasing environmental awareness, fuel cells have attracted attention as clean energy that does not emit CO ₂ or pollutants. Among them, the development of a polymer electrolyte fuel cell (PEFC) using a solid polymer electrolyte that has high energy efficiency and a temperature range of around 100 ° C. and is easy to handle for general use is expected.

A solid polymer fuel cell has as its basic unit a membrane electrode assembly in which a catalyst and a catalyst electrode containing a solid polymer electrolyte are joined to both surfaces of an electrolyte membrane usually made of a solid polymer electrolyte. As the solid polymer electrolyte, a fluorine-based polymer electrolyte such as perfluorosulfonic acid that is generally known as Nafion (registered trademark) manufactured by DuPont is used. In a membrane electrode assembly using perfluorosulfonic acid or the like as a solid polymer electrolyte, protons are conducted in the state of H ₃ O ⁺ , so it is necessary to provide a humidification mechanism, and the system becomes complicated. is there.

  On the other hand, in a polymer electrolyte fuel cell, in order to obtain higher cell performance, it is very important to design a three-phase interface for efficiently transferring hydrogen, oxygen, ions, and electrons in the catalyst electrode. However, a fluorine-based polymer electrolyte such as perfluorosulfonic acid known as Nafion has a problem that proton conductivity is remarkably lowered at a high temperature of 80 ° C. or higher. Therefore, at a high temperature of 80 ° C. or higher, the electrode reaction at the three-phase interface in the catalyst electrode containing a fluorine-based polymer electrolyte such as perfluorosulfonic acid becomes insufficient.

  Thus, it has been proposed to use an ionic liquid as a proton conductive electrolyte having proton conductivity in a high temperature and non-humidified state (see, for example, Patent Documents 1 and 2). The ionic liquid is (1) vapor pressure is zero or extremely low, (2) flame retardant, (3) ionic conductivity, (4) low viscosity, (5) liquid temperature range It has excellent properties as an electrolyte, such as wide, and is expected as an electrolyte for fuel cells under high temperature and non-humidified conditions. However, when an ionic liquid is used, the ionic liquid may flow out of the catalyst electrode, and battery performance may be reduced.

JP 2008-177135 A JP 2009-29846 A

  In order to solve the above-described conventional problems, the present invention provides a fuel cell catalyst layer having excellent power generation performance in a high temperature and non-humidified state, a fuel cell catalyst layer with a substrate using the same, and a fuel cell gas diffusion Provided are an electrode, a fuel cell catalyst layer-electrolyte membrane laminate, a fuel cell membrane electrode assembly and a fuel cell, and a method for producing the same.

  The fuel cell catalyst layer of the present invention is a fuel cell catalyst layer containing an electrolyte and a catalyst, wherein the electrolyte contains an ionic liquid, a solid acid, and phosphoric acids.

  The catalyst layer for a fuel cell with a substrate of the present invention comprises the catalyst layer for a fuel cell of the present invention and a substrate, and the catalyst layer is formed on one main surface of the substrate. Features.

  A gas diffusion electrode for a fuel cell of the present invention comprises the catalyst layer for a fuel cell of the present invention and a gas diffusion layer, and the catalyst layer is disposed on the main surface of the gas diffusion layer. To do.

  The fuel cell catalyst layer-electrolyte membrane laminate of the present invention comprises the fuel cell catalyst layer of the present invention and an electrolyte membrane, and the catalyst layer is disposed on at least one main surface of the electrolyte membrane. It is characterized by being.

  A membrane electrode assembly for a fuel cell of the present invention comprises the catalyst layer for a fuel cell of the present invention, an electrolyte membrane and a gas diffusion layer, and the catalyst layer and the gas diffusion on both main surfaces of the electrolyte membrane. The layers are laminated in this order.

  The fuel cell of the present invention comprises the catalyst layer for a fuel cell of the present invention, an electrolyte membrane, a gas diffusion layer, and a separator, and the catalyst layer, the gas diffusion layer, and the above on both main surfaces of the electrolyte membrane. The separators are stacked in this order.

  The production method of the present invention is a method for producing a catalyst layer for a fuel cell comprising an electrolyte and a catalyst, comprising a step of forming a catalyst layer using a composition for forming a catalyst layer comprising an electrolyte and a catalyst, The catalyst layer forming composition includes a solid acid, an ionic liquid, and phosphoric acids as an electrolyte, or the catalyst layer forming composition includes one or more electrolytes selected from the group consisting of an ionic liquid and phosphoric acids. If not, by applying one or more electrolytes selected from the group consisting of ionic liquid and phosphoric acid to the catalyst layer formed using the catalyst layer forming composition, the ionic liquid, solid acid and phosphoric acid as the electrolyte A catalyst layer containing is obtained.

  The present invention includes a catalyst layer for a fuel cell having excellent power generation performance at high temperature and in a non-humidified state by including an ionic liquid, a solid acid and phosphoric acid as an electrolyte in the catalyst layer, and a substrate using the same A fuel cell catalyst layer, a fuel cell gas diffusion electrode, a fuel cell catalyst layer-electrolyte membrane laminate, a fuel cell membrane electrode assembly and a fuel cell can be provided. Moreover, according to the production method of the present invention, the fuel cell catalyst layer of the present invention can be easily obtained.

FIG. 1 is a schematic cross-sectional view showing an example of a catalyst layer for a fuel cell with a substrate according to Embodiment 2 of the present invention. FIG. 2 is a schematic cross-sectional view showing an example of a fuel cell gas diffusion electrode according to Embodiment 3 of the present invention. FIG. 3 is a schematic cross-sectional view showing an example of a fuel cell catalyst layer-electrolyte membrane laminate according to Embodiment 4 of the present invention. FIG. 4 is a schematic cross-sectional view showing an example of a membrane electrode assembly for a fuel cell according to Embodiment 5 of the present invention. FIG. 5 is a schematic cross-sectional view showing an example of a fuel cell according to Embodiment 6 of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail based on the drawings. Note that the embodiments described below exemplify materials and manufacturing methods for embodying the technical idea of the present invention, and the technical idea of the present invention is limited to the following materials and manufacturing methods. Not what you want. The technical idea of the present invention can be variously modified within the scope of the claims.

[Embodiment 1]
First, a fuel cell catalyst layer will be described as Embodiment 1 of the present invention.

(Fuel cell catalyst layer)
The fuel cell catalyst layer (hereinafter also simply referred to as catalyst layer) according to Embodiment 1 of the present invention includes an electrolyte and a catalyst, and the electrolyte includes an ionic liquid, a solid acid, and phosphoric acids. By adding solid acid and phosphoric acid as an electrolyte in the catalyst layer together with the ionic liquid, the catalyst layer contains phosphoric acids compared to the case where only the ionic liquid and solid acid are included as the electrolyte in the catalyst layer. By being contained, proton conductivity in the catalyst layer is improved. Compared with the case where only the ionic liquid and the phosphoric acid are included in the catalyst layer as an electrolyte, the outflow of the ionic liquid and the phosphoric acid from the catalyst layer can be prevented by containing the solid acid, and the solid Since the acid is responsible for proton conduction, the battery performance can be prevented from being deteriorated due to the outflow of the ionic liquid or phosphoric acid, and the fuel cell can be prevented from corroding due to the leaching of phosphoric acid.

  The thickness of the catalyst layer may be appropriately determined in consideration of the type of electrode substrate, the thickness of the electrolyte membrane, and the like. The thickness of the catalyst layer is, for example, usually 20 to 3000 μm, preferably 20 to 2000 μm.

<Catalyst>
The catalyst is not particularly limited as long as it is a substance that promotes the anode and / or cathode reaction in the fuel cell. For example, platinum-supported carbon, platinum-ruthenium-supported carbon, platinum-cobalt-supported carbon, gold-supported carbon, silver-supported carbon, iron-cobalt-nickel-supported carbon, etc .; platinum black, platinum-ruthenium black, platinum-cobalt Examples thereof include metal fine particles such as black, gold black and silver black; inorganic substances such as molybdenum carbide. Of these, platinum-supporting carbon with high catalytic activity, molybdenum carbide with low phosphoric acid poisoning, and the like are suitable.

<Ionic liquid>
In the present invention, the “ionic liquid” is also referred to as a room temperature molten salt, and means a liquid that is in a liquid state at room temperature (20 ± 15 ° C.) among melts composed only of ions. The ionic liquid is composed of a cation component and an anion component.

  The cation component of the ionic liquid is not particularly limited, and examples thereof include imidazolium derivatives, pyridinium derivatives, pyrrolidinium derivatives, ammonium derivatives, those having a nitrogen-containing heterocyclic ring, guanidinium derivatives, and isouronium derivatives. Among these, from the viewpoint of excellent heat resistance and conductivity, it is preferably at least one selected from the group consisting of an imidazolium derivative and an ammonium derivative, such as 1-methyl-3-methylimidazolium cation, 1-ethyl-3 -More preferably, it is at least one selected from the group consisting of a methylimidazolium cation and a diethylmethylammonium cation.

The anion component of the ionic liquid is not particularly limited. For example, sulfates, sulfonic acids, amides, imides, methanes, halogens, boron-containing anions, phosphates, antimony, hydrofluoride anion, fluorine System anions, thiocyanates and the like. Among these, from the viewpoint of heat resistance, conductivity, etc., it is preferably at least one selected from the group consisting of sulfates, imides and thiocyanates, [CF ₃ SO ₃ ] ⁻ , [(FSO ₂ ) ₂ N] ^- and [SCN] ^- it is more preferably one or more selected from the group consisting of. From the viewpoint of excellent ion conductivity, the anion components are [CF ₃ SO ₃ ] ⁻ , [(FSO ₂ ) ₂ N] ⁻ , [SCN] ⁻ , [HSO ₄ ] ⁻ and bis (trifluoromethanesulfonyl) amide (bis). (Trifluoromethanesulfonyl) amide, also referred to as HTFSI in the following) is preferably one or more selected from the group consisting of [CF ₃ SO ₃ ] ⁻ , [HSO ₄ ] ⁻ and HTFSI. More preferably.

  In the present invention, the ionic liquid preferably contains protic ions. In the present invention, “protic ion” means an ion having proton accepting property and / or proton donating property.

The protic ion is not particularly limited, and examples thereof include proton monohydrogen sulfate ion (HSO ₄ ⁻ ), monohydrogen phosphate ion (HPO ₄ ²⁻ ), dihydrogen phosphate ion (H ₂ PO ₄ ⁻ ), and selenium. Acid monohydrogen ion (HSeO ₄ ⁻ ), pyrohydrogen monohydrogen ion (HP ₂ O ₇ ³⁻ ), dihydrogen pyrophosphate ion (H ₂ P ₂ O ₇ ²⁻ ), trihydrogen pyrophosphate ion (H ₃ P ₂₎ O ₇ ⁻ ), phosphonate monohydrogen ion (H ₂ PO ₃ ⁻ ) and the like.

  The ionic liquid may contain one or more of the above-mentioned cation components. The ionic liquid may contain one or more of the above-described anionic components.

  The ionic liquid can be obtained by a known method (for example, see J. AM. CHEM. SOC. 2010, 132, pages 964-9773, etc.). In the present invention, an ionic liquid produced by a known method may be used, or a commercially available product may be used. Examples of commercially available products include 1-ethyl-3-methylimidazolium bis (fluorosulfonyl) imide [1-Ethyl-3-methylimidazolium bis (fluorosulfonyl) imide] manufactured by Mitsubishi Materials Corporation, Ethyl-3-methylimidazolium triflate [1-Ethyl-3-methylimidazolium triflate], 1-Ethyl-3-methylimidazolium hydrogensulfate [1-Ethyl-3-methylimidazolium hydrosulfate], 1-ethyl-3-methylimidazole Lithium thiocyanate [1-Ethyl-3-methylimidazolium thiocynate] etc. can be used. . Alternatively, an ionic liquid obtained by mixing a commercially available cation component and an anion component, for example, imidazolium bis obtained by mixing imidazole manufactured by Tokyo Chemical Industry Co., Ltd. and HTFSI manufactured by Wako Pure Chemical Industries, Ltd. (Trifluoromethanesulfonyl) amide, 2-ethylimidazole manufactured by Tokyo Chemical Industry Co., Ltd., and imidazolium bis (trifluoromethanesulfonyl) amide obtained by mixing HTFSI manufactured by Wako Pure Chemical Industries, Ltd. It may be used.

<Phosphate>
In the present invention, “phosphoric acids” means orthophosphoric acid and phosphoric acid condensate. Examples of phosphoric acid condensates include pyrophosphoric acid, tripolyphosphoric acid, polyphosphoric acid, and metaphosphoric acid. From the viewpoint of ionic conductivity, concentration, handleability, and the like, it is preferable to use a phosphoric acid (H ₃ PO ₄ ) aqueous solution having a concentration of 75 to 122% by mass as phosphoric acid, and 85 to 122% by mass of phosphoric acid ( It is more preferable to use a H ₃ PO ₄ ) aqueous solution.

<Solid acid>
In the present invention, the “solid acid” means a solid that exhibits acid characteristics. The solid acid is not particularly limited. For example, an inorganic solid acid or an organic solid acid can be used. From the viewpoint of proton conductivity, proton conductivity can be obtained in a temperature range from room temperature to 200 ° C. and in a non-humidified atmosphere. It is preferable to use a solid acid. In the present invention, the non-humidified atmosphere means that intentional humidification is not performed in the atmosphere where the solid acid is placed. Moreover, room temperature means that intentional temperature adjustment is not performed in the atmosphere in which the solid acid is placed for the purpose of the present invention.

  The organic solid acid is not particularly limited as long as it is a solid and an organic acid, but it is preferable to use an organic solid acid having a sulfonic acid group, a naphthalene compound, or the like. Examples of the compound having a sulfonic acid group include benzenesulfonic acid, dodecylbenzenesulfonic acid, 2-naphthalenesulfonic acid, 1,5-naphthalenedisulfonic acid, 2,6-naphthalenedisulfonic acid, 1,3,6-naphthalenetri Sulfonic acid, 1,3,5,7-naphthalene tetrasulfonic acid and the like can be used. Examples of the naphthalene-based compound include naphthalene, 2-methylnaphthalene, 1-naphthol, 2-naphthol, naphthoic acid, naphthonitrile, naphthylamine, and acenaphthene. You may use the said organic acid individually or in mixture of 1 or more types.

  As the inorganic solid acid, for example, an inorganic solid acid having proton conductivity can be used, and an inorganic salt having proton conductivity is preferable.

  Examples of the inorganic salt having proton conductivity include metal phosphates and metal sulfates.

  Examples of the metal phosphate include compounds such as orthophosphate and pyrophosphate. Specific examples of the metal phosphate include orthophosphates and pyrophosphates such as tin, zirconium, cesium, and tungsten.

  As the pyrophosphate, a metal phosphate represented by the following general formula (1) is preferably used from the viewpoint of excellent proton conductivity.

[Chemical 1]
M _1-x D _x P ₂ O ₇ (1)

  However, in the general formula (1), x is 0 ≦ x <0.5, and M (main metal) is Zr, Cs, Sn, Ti, Si, Ge, Pb, Hf, Ca, Mg, W, Na And D (doped metal) is a kind selected from the group consisting of Al, In, B, Ga, Sc, Yb, Ce, La, Sb, Y, Nb and Mg. .

  The metal phosphate represented by the general formula (1) includes Zr, Cs, Sn, Ti, Si, Ge, Pb, Hf, Ca, Mg, W, Na, or Al as the main metal, Pyrophosphates doped with different metals are preferred. When a doped metal is used, it is preferable to use Sn, Cs, Ti, or Zr as the main metal from the viewpoint of stability as a phosphate. More preferably, it is a pyrophosphate in which a part of a metal such as tin or cesium is substituted with a doped metal element such as indium, aluminum or antimony.

  As the doped metal, for example, when Sn is used as the main metal, In, Al, and the like are preferable because they can be dissolved in the main metal. The mixing ratio of the main metal and the dope metal varies depending on the solid solubility limit. However, when Sn is used as the main metal and In is used as the dope metal, for example, the molar ratio is Sn: In = 7: 3-9.8: 0.2 A range of is desirable.

  The metal phosphate represented by the general formula (1) can be synthesized, for example, by heating one or more metal oxides and phosphoric acid and performing heat treatment.

  The metal oxide is not particularly limited as long as it can generate phosphoric acid and a crystalline salt. Examples thereof include oxides of Zr, Cs, Sn, Ti, Si, Ge, Pb, Hf, Ca, Mg, W, Na, and Al. As the phosphoric acid, either liquid phosphoric acid or solid phosphoric acid may be used. From the viewpoint of avoiding the problem of loss of phosphoric acid during heat treatment, it is preferable to use solid phosphoric acid. As solid phosphoric acid, for example, ammonium monohydrogen phosphate, ammonium dihydrogen phosphate and the like can be used.

  Specifically, the metal phosphate represented by the general formula (1) can be produced as follows. First, a compound containing a main metal such as tin (hereinafter simply referred to as a main metal compound) and a compound containing a doped metal such as indium (hereinafter also simply referred to as a doped metal compound) and liquid phosphoric acid are mixed. A mixture is obtained. Next, water is added to the obtained mixture, and the mixture is stirred and dispersed with a stirrer or the like at a temperature of 100 to 300 ° C. for 1 to 3 hours to obtain a dispersion. The obtained dispersion is put in a crucible and baked at a temperature of 300 to 700 ° C. for 1 to 3 hours, for example. Since phosphoric acid may be lost in the high temperature state, it is desirable to add the liquid phosphoric acid in excess, for example, 1.1 to 1.5 times the molar equivalent. In addition, as a main metal compound and dope metal compound, a metal oxide, a metal hydroxide, a metal chloride, a metal nitrate etc. can be used, for example.

  In the above, in order to avoid the problem of disappearance of phosphoric acid during firing, solid phosphoric acid may be used instead of liquid phosphoric acid. As the solid phosphoric acid, for example, using ammonium monohydrogen phosphate, ammonium dihydrogen phosphate, etc., a metal oxide containing a main metal such as tin and a metal oxide containing a doped metal such as indium and a predetermined number of moles. Mix with. The metal oxide containing the main metal and the metal oxide containing the doped metal are preferably mixed at a molar ratio of the main metal to the doped metal of, for example, 9: 1 to 1: 1. The obtained mixture is put into a crucible and baked at a temperature of 300 to 650 ° C. for 1 to 3 hours, for example. The resulting product can then be ground in an agate bowl to give the desired metal phosphate. By using solid phosphoric acid, a molar equivalent of phosphoric acid reacts with the metal oxide, and the excess is volatilized at a high temperature, so that excess phosphoric acid does not adhere and a reproducible metal phosphate can be obtained. it can.

Moreover, the said metal phosphate can also be produced by a coprecipitation method. For example, tin chloride pentahydrate (SnCl ₄ .5H ₂ O) and indium chloride tetrahydrate (InCl ₃ .4H ₂ O) are added at a predetermined concentration so that a molar ratio of tin to indium is about 9: 1. After adjusting to an aqueous solution, while stirring with a stirrer, an aqueous ammonia solution is added dropwise until the pH becomes 7, whereby a small amount of indium hydroxide (In (OH) ₃ ) is uniformly contained in tin hydroxide (Sn (OH) ₄ ). A precipitate in the state present in is obtained. Thereafter, the precipitate is sucked and filtered to dry, the dried precipitate and phosphoric acid are mixed, and heat treatment is performed at about 200 ° C. for about 2 hours in a reducing atmosphere to obtain a metal phosphate. . Finally, wash with deionized water. According to the coprecipitation method, a metal phosphate in which a doped metal is uniformly doped into a main metal phosphate is prepared by simultaneously precipitating a plurality of types of hardly soluble salts from a solution containing a plurality of desired metal ions. be able to.

Further, as the inorganic salt having proton conductivity, a complex of a heteropolyacid and an inorganic salt may be used. Examples of the inorganic salt include hydrogen sulfate and hydrogen phosphate. Examples of the hydrogen sulfate include cesium hydrogen sulfate and potassium hydrogen sulfate. Examples of the hydrogen phosphate include cesium hydrogen phosphate. Further, cesium carbonate (Cs ₂ CO ₃ ), cesium sulfate (Cs ₂ SO ₄ ), or the like may be used instead of hydrogen sulfate or hydrogen phosphate. Examples of the heteropolyacid include tungsten phosphoric acid (H ₃ PW ₁₂ O ₄₀ : WPA). From the viewpoint of proton conductivity, the complex of heteropolyacid and inorganic salt is preferably a complex of hydrogensulfate and heteropolyacid, more preferably a complex of potassium hydrogensulfate and tungsten phosphate obtained by a mechanochemical method. Is the body.

A complex of tungsten phosphoric acid and potassium hydrogen sulfate (KHSO ₄ ), which is a kind of a complex of a heteropolyacid and an inorganic salt, can be produced by, for example, the following mechanochemical method. WPA (H ₃ PW ₁₂ O ₄₀ : 12 Tungsto (VI) phosphoric acid n hydrate) is preliminarily dried at a temperature of 60 ° C. for 5 to 24 hours to form hexahydrate (WPA · 6H ₂ O). Next, the obtained WPA · 6H ₂ O, potassium hydrogen sulfate (KHSO ₄ ) and the ball are put in an agate pot. Then, the complex of tungsten phosphoric acid and potassium hydrogen sulfate (KHSO ₄ ) is obtained by mixing at 720 rpm for 10 minutes with a planetary ball mill (manufactured by Frichce Japan KK, P-7). It is preferable that the compounding quantity of tungsten phosphoric acid and potassium hydrogensulfate is 1: 99-40: 60 by molar ratio, for example.

  In the mechanochemical method, a composite of tungsten phosphate and potassium hydrogen sulfate is synthesized by utilizing a large mechanical energy such as impact and friction obtained by milling using a ball mill or the like. Therefore, when a complex of tungsten phosphoric acid and potassium hydrogen sulfate is produced by the above mechanochemical method, it is relatively easy to produce because a high-temperature process is not required as in the production of metal phosphate. There is an advantage.

It is thought that the above-mentioned milling treatment is related to the improvement of conductivity by the formation of hydrogen bonds in the form of Bronsted acid-base pairs between the KPA Keggin anion PW ₁₂ O ₄₀ ³⁻ and the HSO ₄ ⁻ anion of KHSO _4. It is done. Combining hydrogen sulfate and heteropoly acid by mechanochemical method, introducing defect structures and random structures at high density on the surface of inorganic solids, and designing a hydrogen bond network is a composite with high proton conductivity in a wide temperature range It is an important guide for synthesizing the body.

  Moreover, as said solid acid, it is preferable to use the metal phosphate or metal sulfate represented by following General formula (2) from a viewpoint that it is excellent in proton conductivity.

[Chemical formula 2]
L _a H _b (XO _t ) _c (2)

  However, in General formula (2), L is 1 type chosen from the group which consists of K, Rb, and Cs, X is 1 type chosen from the group which consists of P and S, and a, b, c, and t are rational numbers. It is.

  Among the metal phosphates represented by the general formula (2), it is more preferable to use a metal phosphate or a metal sulfate represented by the following general formula (3).

[Chemical formula 3]
Cs _a H _b (XO _t ) _c (3)

Examples of the metal phosphate or metal sulfate represented by the general formula (3) include cesium phosphate (cesium phosphate) and cesium sulfate. Examples of the cesium phosphate include cesium dihydrogen phosphate (CsH ₂ PO ₄ ), cesium dihydrogen phosphate (CsH ₅ (PO ₄ ) ₂ ), and the like.

Further, as the solid acid, a complex of cesium phosphoric acid and silicon phosphate (SiP ₂ O ₇ ) may be used. Examples of the cesium phosphoric acid include cesium dihydrogen phosphate (CsH ₂ PO ₄ ), cesium dihydrogen phosphate (CsH ₅ (PO ₄ ) ₂ ), and the like. In addition, cesium phosphate, silicon phosphate, and those composites are, for example, “Toshiaki Matsui, Tomokazu Kukino, Ryuji Kikuchi, and Koichi Eguchi, The 3 A3, A3. "Toshiaki Matsui, Tomokazu Kukino, Ryuji Kikuchi, and koichi Eguchi, Electrochemical Acta 51 (2006) 3719-3723" and the like.

Complex of cesium dihydrogen phosphate (CsH ₂ PO ₄ ) and silicon phosphate (SiP ₂ O ₇ ) or cesium dihydrogen phosphate (CsH ₅ (PO ₄ ) ₂ ) and silicon phosphate (SiP ₂ O ₇ ) For example, the composite is prepared as follows.

First, cesium dihydrogen phosphate (CsH ₂ PO ₄ ) or cesium dihydrogen phosphate (CsH ₅ (PO ₄ ) ₂ ) is prepared as follows. Cesium carbonate (Cs ₂ CO ₃ ) and water are mixed and stirred with a stir bar using a stirrer or the like. Subsequently, liquid phosphoric acid is dripped little by little, and water is evaporated, stirring at the temperature of 100-150 degreeC for 1-3 hours. Then, it puts into oven and is dried at the temperature of 100-150 degreeC, for example. The drying time is, for example, 1 day to several days. Next, the obtained product is pulverized in an agate bowl into a powder form to obtain the desired cesium dihydrogen phosphate (CsH ₂ PO ₄ ) or cesium dihydrogen phosphate (CsH ₅ (PO ₄ ) ₂ ). Can do.

Next, silicon phosphate (SiP ₂ O ₇ ) is produced as follows. A mixture of silicon dioxide (SiO ₂ ) and liquid phosphoric acid is placed in an agate noodle and mixed until it becomes a starchy candy. Then, it puts into an alumina crucible and fires at a temperature of 100 to 700 ° C. The firing time is, for example, 30 to 80 hours. Then, the obtained product can be pulverized in an agate bowl to obtain the desired silicon phosphate (SiP ₂ O ₇ ).

Next, cesium dihydrogen phosphate (CsH ₂ PO ₄ ) or cesium dihydrogen phosphate (CsH ₅ (PO ₄ ) ₂ ) and silicon phosphate (SiP ₂ O ₇ ) are blended in a predetermined number of moles. The obtained mixture is dispersed by a pod mill, a ball mill or the like, and a composite of cesium dihydrogen phosphate (CsH ₂ PO ₄ ) and silicon phosphate (SiP ₂ O ₇ ) or cesium dihydrogen phosphate (CsH ₅ (PO ₄ ) A composite of ₂ ) and silicon phosphate (SiP ₂ O ₇ ) is obtained. The dispersion time is, for example, 1 to 30 hours. The blending amount of cesium dihydrogen phosphate or cesium dihydrogen phosphate and silicon phosphate is preferably 1: 4 to 2: 1 in molar ratio.

As the solid acid, potassium phosphate, silicon phosphate (SiP ₂ O ₇ ), or a complex of potassium phosphate and silicon phosphate (SiP ₂ O ₇ ) may be used. Examples of the potassium phosphoric acid include potassium dihydrogen phosphate (KH ₂ PO ₄ ) and potassium pentahydrogen diphosphate (KH ₅ (PO ₄ ) ₂ ). Complex of potassium dihydrogen phosphate (KH ₂ PO ₄ ) and silicon phosphate (SiP ₂ O ₇ ) or complex of potassium dihydrogen phosphate (KH ₅ (PO ₄ ) and silicon phosphate (SiP ₂ O ₇ ) The bodies are cesium dihydrogen phosphate (CsH ₂ PO ₄ ) and silicon phosphate (SiP ₂ O ₇ ), respectively, except that potassium carbonate (K ₂ CO ₃ ) is used instead of cesium carbonate (Cs ₂ CO ₃ ). ) Or a complex of cesium dihydrogen phosphate (CsH ₅ (PO ₄ ) ₂ ) and silicon phosphate (SiP ₂ O ₇ ).

  Since the organic solid acid dissolves in the solvent, the compatibility with the binder component is good, and the dispersibility becomes good at the time of preparing the electrolyte composition, so that the effect of improving the quality of the electrolyte membrane is easily obtained. On the other hand, since an inorganic solid acid is excellent in heat resistance and durability, it is easy to obtain an effect that the mechanical strength after forming an electrolyte into a film becomes good.

  Although the said solid acid is not specifically limited, In a catalyst layer, a particle size is 0.1-200 micrometers, Preferably it is 0.1-150 micrometers. In addition, the solid acid as a raw material before forming the catalyst layer also has a particle size of 0.1 to 200 μm, preferably 0.1 to 150 μm. When the particle size of the solid acid is 0.1 to 200 μm, the dispersibility at the time of preparing the composition containing the solid acid is improved, and a catalyst layer having good film quality is easily obtained. In the present invention, the particle size of the solid acid can be measured using a scanning electron microscope (SEM) or the like.

<Binder>
The catalyst layer may further contain a binder. By including the binder, the mechanical strength of the catalyst layer is improved.

  The binder is not particularly limited as long as it has binding properties. For example, a fluorine polymer, a hydrocarbon polymer, a fluorine ionomer, a hydrocarbon ionomer, an epoxy resin, an acrylic resin, or the like is used. Can do. Especially, what has the acid resistance in the range of pH 1-3 and the heat resistance in the temperature range of 50-300 degreeC is preferable. Moreover, you may have ion conductivity.

  Although it does not specifically limit as said fluorine-type polymer, For example, tetrafluoroethylene (PTFE), a polyvinylidene fluoride, a fluoroethylene-hexafluoropropylene copolymer (FEP), a tetrafluoroethylene perfluoroalkyl vinyl ether copolymer A fluororesin such as (PFA) can be used.

  The hydrocarbon polymer is a polymer having a hydrocarbon compound as a main skeleton, such as polyimide, polyamideimide, polystyrene sulfide, polybenzimidazole, polypyridine, polypyrimidine, polyimidazole, polybenzothiazole, poly Benzooxazole, polyoxadiazol, polyxylone, polyquinoxaline, polythiadiazol, polytetrazavilen, polyoxazole, polythiazole, polyvinyl pyridine, polyvinyl imidazole, and the like can be used.

  The fluorine ionomer is not particularly limited. For example, perfluorosulfonic acid such as Nafion (registered trademark) manufactured by DuPont, Flemion (registered trademark) manufactured by Asahi Glass Co., and Aciplex (registered trademark) manufactured by Asahi Kasei Corporation. For example, a sulfonyl fluoride vinyl ether (SFVE) -tetrafluoroethylene copolymer such as Aquivion (registered trademark) manufactured by Asahi Kasei Corporation can be used.

  The hydrocarbon ionomer is not particularly limited. For example, polyarylene ether sulfonic acid, polystyrene sulfonic acid, syndiotactic polystyrene sulfonic acid, polyphenylene ether sulfonic acid, modified polyphenylene ether sulfonic acid, polyether sulfone sulfonic acid, polyether. Ether ketone sulfonic acid and polyphenylene sulfide sulfonic acid can be used.

  As the epoxy resin, bisphenol A type epoxy resin, novolac type phenol resin, or the like can be used. Also, a hybrid resin of the above resin and silica can be used.

  As the acrylic resin, polymethyl methacrylate, polystyrene, or the like can be used. Also, a hybrid resin of the above resin and silica can be used.

  The binder may be a cellulosic polymer. Examples of the cellulose polymer include methyl cellulose, carboxymethyl cellulose, and cellulose acetate.

  Among the above-mentioned binders, PTFE, polyvinylidene fluoride, perfluorosulfonic acid, cellulose acetate, sulfonyl fluoride vinyl ether (SFVE) -tetrafluoroethylene copolymer, polyether ether from the viewpoint of excellent durability and binding properties. Ketone sulfonic acid (sulfonated polyetheretherketone), polybenzimidazole, polyimidazole, polypyridine, and polypyrimidine are preferably used. The polyether ether ketone sulfonic acid is not particularly limited. L. Those synthesized by the method described in Di Vona et al, Polymer 46 (2005), pages 1754-1758 can be used.

  Only one type of the binder described above may be used, or two or more types may be used in appropriate combination.

  Hereinafter, the manufacturing method of the catalyst layer for fuel cells is demonstrated.

(Method for producing catalyst layer for fuel cell)
The catalyst layer for the fuel cell is not particularly limited, but can be manufactured by the following method, for example.
(1) A catalyst layer is formed using a composition for forming a catalyst layer containing an ionic liquid, a solid acid, phosphoric acids and a catalyst, and a fuel cell catalyst layer containing an ionic liquid, a solid acid, phosphoric acids and a catalyst is formed. obtain.
(2) After forming a catalyst layer using a catalyst layer forming composition containing a solid acid and a catalyst, an ionic liquid and phosphoric acid are applied to the main surface of the obtained catalyst layer, and the ionic liquid and the solid acid are applied. And a catalyst layer for a fuel cell containing phosphoric acid and a catalyst.
(3) After forming a catalyst layer using a composition for forming a catalyst layer containing a solid acid, an ionic liquid, and a catalyst, phosphoric acid is applied on the main surface of the obtained catalyst layer, and the ionic liquid and the solid acid are applied. And a catalyst layer for a fuel cell containing phosphoric acid and a catalyst.
(4) After forming a catalyst layer using a composition for forming a catalyst layer containing a solid acid, phosphoric acid and a catalyst, an ionic liquid is applied onto the main surface of the obtained catalyst layer, and the ionic liquid and the solid acid are applied. And a catalyst layer for a fuel cell containing phosphoric acid and a catalyst.

  In the manufacturing method of said (1)-(4), from a viewpoint of preventing the loss | disappearance of phosphoric acids and ionic liquid by the heat | fever in the drying process at the time of catalyst layer formation, the catalyst layer which does not contain an ionic liquid and / or phosphoric acid (2) to (4) are preferable, in which the ionic liquid and / or phosphoric acid is applied on the main surface of the catalyst layer, and the dispersibility of the ionic liquid and / or phosphoric acid in the catalyst layer is preferable. From the viewpoint, the production method of (1) in which a catalyst layer is formed using a composition for forming a catalyst layer containing an ionic liquid, a solid acid, phosphoric acid, and a catalyst is preferable.

<Composition for forming catalyst layer>
As the catalyst layer forming composition, a paste of catalyst paste can be used. The catalyst paste is obtained by mixing and dispersing a mixture containing a solid acid, a catalyst, and a solvent with a disperser. In addition, the said catalyst paste may also contain an ionic liquid and / or phosphoric acid as needed. As the disperser, an ultrasonic disperser, a homogenizer, a ball mill, or the like can be used. What is necessary is just to use what was mentioned above as an ionic liquid, a solid acid, phosphoric acids, and a catalyst.

  The solvent is not particularly limited as long as it can disperse the catalyst. For example, water, ethanol, methanol, 1-butanol, t-butanol, propanol, N-methylpyrrolidone, dimethylacetamide, dimethylsulfoxide, dimethylformamide and the like can be used.

  In the catalyst paste, the total concentration of the solid content and the ionic liquid containing the solid acid and the catalyst is preferably 50% by mass or less, more preferably 40% by mass or less, from the viewpoint of coatability. Further, from the viewpoint of coating properties and proton conductivity, the blending amount of the solid acid and the ionic liquid is preferably 1:50 to 10: 1, more preferably 1:50 to 1: 5, in terms of mass ratio. It is. Further, from the viewpoint of proton conductivity, the blending amount of the solid acid and the catalyst is preferably 1:10 to 1: 0.1, more preferably 1: 5 to 1: 0.25 in terms of mass ratio. is there. Further, from the viewpoint of proton conductivity, the blending amount of the solid acid and phosphoric acid is preferably 1:50 to 10: 1, more preferably 1:50 to 1: 5 in terms of mass ratio.

  Further, when the metal phosphate represented by the above general formula (1) is used as the solid acid, the number of atoms of the metal element of the metal phosphate [m] and the number of atoms of the metal element to be doped in the catalyst paste [N] and the number of phosphorus atoms [p] of the metal phosphate preferably satisfy the following mathematical formula (1).

[Equation 1]
2 <[p] / ([m] + [n]) ≦ 4 (1)

  More preferably, the following mathematical formula (2) is satisfied.

[Equation 2]
2.4 ≦ [p] / ([m] + [n]) ≦ 3.2 (2)

  By satisfy | filling the said Numerical formula (1), while having high proton conductivity, a catalyst layer with favorable moldability is obtained. When the value of the above formula [p] / ([m] + [n]) is 2 or less, the amount of phosphorus is decreased, and there is a possibility that proton conductivity is difficult to improve. On the other hand, if the value of the above formula [p] / ([m] + [n]) exceeds 4, there is a possibility that the amount of phosphorus is too large to prevent the seepage of phosphoric acid from the catalyst layer. Since the moisture absorption in the atmosphere is high and the catalyst layer becomes brittle, the shape may not be maintained.

  The catalyst paste may further contain a binder. The amount of the binder (solid content) added is preferably 50% by mass or less, and more preferably 40% by mass or less, based on the total mass of the solid content in the catalyst paste and the ionic liquid. In this case, after adding the catalyst and the solid acid to the binder solution or dispersion, a solvent may be added to produce a catalyst paste. A solvent that does not aggregate the binder is used. Specifically, water, ethanol, methanol, 1-butanol, t-butanol, propanol, N-methylpyrrolidone, dimethylacetamide, dimethylsulfoxide, dimethylformamide and the like can be used.

<Formation of catalyst layer>
Although the formation method of a catalyst layer is not specifically limited, For example, after apply | coating a catalyst paste on a base material and drying, the catalyst layer for fuel cells can be formed. The method for forming the catalyst layer will be described in detail in Embodiment 2.

  As described above, by including an ionic liquid, a solid acid, phosphoric acid, and a catalyst in the catalyst layer, a catalyst layer having excellent power generation performance at a high temperature and in a non-humidified state can be obtained. In addition, in this way, not only the ionic liquid or phosphoric acid but also the ionic liquid, phosphoric acid and solid acid are combined and contained as an electrolyte in the catalyst layer, thereby preventing the ionic liquid and phosphoric acid from flowing out of the catalyst layer. It is also possible to prevent deterioration of battery performance due to outflow of ionic liquid and phosphoric acid, and corrosion of the fuel cell due to leaching of phosphoric acid.

[Embodiment 2]
Hereinafter, a catalyst layer for a fuel cell with a substrate will be described as Embodiment 2 of the present invention.

<Catalyst layer for fuel cell with substrate>
FIG. 1 is a schematic sectional view showing an example of a catalyst layer for a fuel cell with a substrate according to Embodiment 2 of the present invention. As shown in FIG. 1, the catalyst layer 11 for a fuel cell with a substrate includes a catalyst layer 2 and a substrate 7, and the catalyst layer 2 is formed on one main surface of the substrate 7. .

  The said base material should just be a support body which can apply | coat a catalyst paste, and is not specifically limited. For example, as the substrate, for example, a film substrate, coated paper, non-coated paper, or the like can be used. The film substrate is not particularly limited as long as it is a sheet-like or film-like substrate. For example, a metal foil, a polymer film, etc. can be used. As the coated paper, for example, art paper, coated paper, lightweight coated paper or the like can be used, and as the non-coated paper, for example, notebook paper, copy paper or the like can be used.

  Polymer films include polyimide, polyethylene terephthalate (PET), polyparvanic acid aramid, polyamide (nylon), polysulfone, polyethersulfone, polyphenylene sulfide, polyetheretherketone, polyetherimide, polyarylate, polyethylene naphthalate, etc. An example of the polymer film is shown. Further, heat resistance of polyethylene tetrafluoroethylene copolymer (ETFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroperfluoroalkyl vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), etc. A polymer film made of a conductive fluororesin can also be used. Especially, it is preferable to use the polymer film comprised from polyester, a polyimide, PTFE, etc. from a viewpoint that it is excellent in heat resistance and durability. Moreover, the polymer film comprised from PTFE and polyester is more preferable from the point of the dimensional stability in the manufacturing process of a catalyst layer, and peelability. In order to improve the releasability from the catalyst layer, a base material such as a polymer film provided with a release layer, a release layer or the like may be used.

  The catalyst layer 11 for a fuel cell with a substrate is obtained, for example, by applying a catalyst paste on a substrate and then drying it. The coating method is not particularly limited, and for example, a coating method such as screen printing, blade coating, die coating, spray coating, dispenser coating, and ink jet coating can be used. Among these, it is preferable to use screen printing or blade coating from the viewpoint of easy preparation of the catalyst paste. In addition, when a transfer substrate is used as the substrate, the coating method includes general methods such as knife coater, bar coater, spray, dip coater, spin coater, roll coater, die coater, curtain coater, screen printing, rolling method, etc. A coating method can be used, and in the case of thick coating, it is preferable to use a rolling method.

  In addition, in the above, the catalyst layer 2 can be formed by peeling the substrate from the catalyst layer 11 for a fuel cell with a substrate. Further, the substrate may be peeled by a normal method, and is not particularly limited. For example, the substrate can be peeled by 180 ° peeling.

As the coating amount of the catalyst paste on the substrate, for example, when platinum-supported carbon is used as a catalyst, the platinum-supported amount is 0.1 to 3.0 mg / cm ² , preferably 0.1 to 1.5 mg / cm ² . cm ² .

  Moreover, in the above, drying temperature is 50-300 degreeC, for example, Preferably it is 100-250 degreeC. If the drying temperature is lower than 50 ° C, the solvent contained in the catalyst paste may not be removed. On the other hand, when the drying temperature exceeds 300 ° C., the binder may be thermally decomposed. The drying time is, for example, 10 minutes to 5 hours, preferably 10 minutes to 3 hours. Examples of the drying method include natural drying, far-red drying, hot air drying, reduced pressure drying, and heating.

  In addition, the application of the ionic liquid and / or phosphoric acid to the main surface of the catalyst layer not containing the ionic liquid and / or phosphoric acid is performed by the same application method as that for applying the catalyst paste onto the substrate. It can be carried out. From the viewpoint of coating properties and proton conductivity, the blending amount of the solid acid in the catalyst paste and the coating amount of the ionic liquid is preferably 1:50 to 10: 1, more preferably 1: 50-1: 5. Further, from the viewpoint of coating properties and proton conductivity, the blending amount of the solid acid and the coating amount of phosphoric acids in the catalyst paste is preferably 1:50 to 10: 1, more preferably, by mass ratio. 1: 50-1: 5.

[Embodiment 3]
Hereinafter, a fuel cell gas diffusion electrode will be described as a third embodiment of the present invention.

<Gas diffusion electrode for fuel cell>
FIG. 2 is a schematic cross-sectional view showing an example of a fuel cell gas diffusion electrode according to Embodiment 3 of the present invention. As shown in FIG. 2, the fuel cell gas diffusion electrode 12 includes a catalyst layer 2 and a gas diffusion layer 4, and the catalyst layer 2 is disposed on the main surface of the gas diffusion layer 4. In FIG. 2, the same parts as those in FIG. 2 and 1 have the same function.

  The gas diffusion layer 4 is made of a conductive material having gas diffusibility, such as a porous body, so that fuel gas or oxidant gas can flow therethrough.

  The thickness of the gas diffusion layer 4 may be determined as appropriate in consideration of the thickness of the catalyst layer and the electrolyte membrane. The thickness of the gas diffusion layer 4 is, for example, 100 to 400 μm, preferably 150 to 350 μm.

  As the gas diffusion layer, for example, carbon paper, carbon cloth, carbon felt or the like is used. Moreover, you may use what performed the water-repellent process to these. Further, it is desirable to use a gas diffusion layer provided with a planarization layer in order to prevent the catalyst paste from penetrating into the gas diffusion layer when the catalyst paste is applied to the gas diffusion layer.

  The fuel cell gas diffusion electrode 12 is manufactured, for example, by applying the same catalyst paste as described in the first embodiment on one main surface of the gas diffusion layer 4 and drying to form a catalyst layer. be able to.

  The application of the catalyst paste to the gas diffusion layer 4 can be performed by a method similar to the method of applying the catalyst paste to the base material when forming the catalyst layer in the second embodiment. Moreover, drying can be performed on the same conditions as the drying at the time of formation of the catalyst layer in the said Embodiment 2. FIG.

Moreover, as a coating amount of the catalyst paste on the gas diffusion layer, for example, when platinum-supported carbon is used, the platinum-supported amount is 0.1 to 3.0 mg / cm ² , preferably 0.1 to 1.5 mg / cm ² . cm ² .

  Alternatively, the fuel cell gas diffusion electrode 12 is formed on the gas diffusion layer 4 so that the main surface of the catalyst layer 2 and the main surface of the gas diffusion layer 4 are in contact with the fuel cell catalyst layer 11 with the base material of the second embodiment. It is possible to produce the laminate by performing hot press treatment such as hot pressing from both sides of the obtained laminate, and then peeling the substrate 7.

  The hot press process is not particularly limited, and can be performed by various press processes. Moreover, the pressure at the time of hot pressing is not particularly limited, but is usually 0.5 to 10 MPa, preferably 1 to 10 MPa, for example. Moreover, the temperature at the time of hot pressing is not particularly limited, but is usually 30 to 200 ° C., preferably 50 to 250 ° C., for example. Moreover, what is necessary is just to determine suitably the press time at the time of hot pressing according to temperature, for example, is 10 to 240 seconds normally, Preferably it is 30 to 150 seconds.

  In addition, when the catalyst paste which does not contain an ionic liquid and / or phosphoric acid is used, the gas diffusion electrode 12 for fuel cells was described on Embodiment 1 or 2 on one main surface on the gas diffusion layer 4. After forming a catalyst layer that does not contain an ionic liquid and / or phosphoric acid, the ionic liquid and / or phosphoric acid is applied on the main surface of the catalyst layer to form a solid acid, ionic liquid, phosphoric acid, catalyst. It can manufacture by forming the catalyst layer containing this.

  According to the present embodiment, it is possible to provide a gas diffusion electrode for a fuel cell that has excellent power generation performance in a high temperature and non-humidified state.

[Embodiment 4]
Hereinafter, as a fourth embodiment of the present invention, a fuel cell catalyst layer-electrolyte membrane laminate will be described.

<Catalyst layer for fuel cell-electrolyte membrane laminate>
FIG. 3 is a schematic cross-sectional view showing an example of a fuel cell catalyst layer-electrolyte membrane laminate according to Embodiment 4 of the present invention. As shown in FIG. 3, the fuel cell catalyst layer-electrolyte membrane laminate 13 includes a catalyst layer 2 (2a, 2b) and an electrolyte membrane 1, and the catalyst layer 2 (2a, 2b) gas diffuses. It is arranged on both main surfaces of the layer 4. In FIG. 3, the same parts as those in FIG. 3 and FIG. 1 have the same functions.

  The electrolyte membrane 1 is preferably, for example, a fluorine-based electrolyte membrane or a hydrocarbon-based electrolyte membrane. Moreover, the electrolyte membrane comprised with proton conductive electrolytes, such as the solid acid mentioned above, an ionic liquid, and phosphoric acids, may be sufficient. An electrolyte membrane composed of phosphoric acid-doped polybenzimidazole can also be used.

  Examples of the fluorine-based electrolyte membrane include an electrolyte membrane composed of perfluorosulfonic acid or the like. Examples of the hydrocarbon electrolyte membrane include polyarylene ether sulfonic acid, polystyrene sulfonic acid, syndiotactic polystyrene sulfonic acid, polyphenylene ether sulfonic acid, modified polyphenylene ether sulfonic acid, polyether sulfone sulfonic acid, and polyether ether ketone sulfonic acid. And an electrolyte membrane composed of polyphenylene sulfide sulfonic acid or the like.

  In the catalyst layer-electrolyte membrane laminate 13 for the fuel cell, the same catalyst paste as described in the first embodiment is applied on both main surfaces of the electrolyte membrane 1 and dried to form the catalyst layer 2 (2a, 2b). ).

  The application of the catalyst paste to the electrolyte membrane 1 can be performed by a method similar to the method of applying to the base material when forming the catalyst layer in the second embodiment. Moreover, drying can be performed on the same conditions as the drying at the time of formation of the catalyst layer in the said Embodiment 2. FIG.

The coating amount of the catalyst paste to the electrolyte membrane 1, for example, when using a platinum-supported carbon, 0.1-3.0 mg / cm ² platinum loading amount, preferably 0.1 to 1.5 / cm ² It is.

  Alternatively, the fuel cell catalyst layer-electrolyte membrane laminate 13 is the same as the fuel cell catalyst layer 11 with the base material of Embodiment 2 in that the main surface of the catalyst layer 2 and the main surface of the electrolyte membrane 1 are in contact with each other. It can be produced by disposing the substrate 7 on the substrate 1 and subjecting the obtained laminate to hot pressing such as hot pressing from both sides, and then peeling the substrate 7. The hot press can be performed under the same conditions as the hot press described in the third embodiment.

  In addition, when the catalyst paste which does not contain an ionic liquid and / or phosphoric acid is used, the catalyst layer-electrolyte membrane laminated body 13 for fuel cells is Embodiment 1-2 on both main surfaces on the electrolyte membrane 1. In the same manner as described above, after forming a catalyst layer that does not contain an ionic liquid and / or phosphoric acid, an ionic liquid and / or phosphoric acid is applied onto the main surface of the catalyst layer, and a solid acid, ionic liquid, It can manufacture by forming the catalyst layer containing acids and a catalyst.

  According to this embodiment, it is possible to provide a fuel cell catalyst layer-electrolyte membrane laminate having excellent power generation performance at high temperatures and in a non-humidified state.

[Embodiment 5]
Hereinafter, a fuel cell membrane electrode assembly will be described as Embodiment 5 of the present invention.

<Membrane electrode assembly for fuel cell>
FIG. 4 is a schematic cross-sectional view showing an example of a membrane electrode assembly for a fuel cell according to Embodiment 5 of the present invention. As shown in FIG. 4, the fuel cell membrane electrode assembly 14 includes a catalyst layer 2 (2a, 2b), an electrolyte membrane 1, and a gas diffusion layer 4 (4a, 4b). Catalyst layers 2a and 2b and gas diffusion layers 4a and 4b are laminated in this order on both main surfaces. In FIG. 4, the same parts as those in FIGS. 4 and FIGS. 1 to 3 have the same functions.

  For example, the fuel cell membrane electrode assembly 14 uses the fuel cell gas diffusion electrode 12 described in the third embodiment so that the main surface of the catalyst layer 2 (2a, 2b) and the main surface of the electrolyte membrane 1 are in contact with each other. It can arrange | position each on the film | membrane 1 and it can produce by performing hot press processes, such as a hot press, from the both sides of the obtained laminated body. The hot pressing can be performed under the same conditions as described in the third embodiment. The gas diffusion electrode 12 includes a cathode side catalyst electrode 12a disposed on the cathode side and an anode side catalyst electrode 12b disposed on the anode side.

  According to this embodiment, it is possible to provide a membrane electrode assembly for a fuel cell that has excellent power generation performance at high temperatures and in a non-humidified state.

[Embodiment 6]
Hereinafter, a fuel cell will be described as a sixth embodiment of the present invention.

(Fuel cell)
FIG. 5 is a schematic cross-sectional view showing an example of a fuel cell according to Embodiment 6 of the present invention. As shown in FIG. 5, the fuel cell 20 according to Embodiment 6 of the present invention includes a fuel cell catalyst layer 2 (2a, 2b), an electrolyte membrane 1, a gas diffusion layer 4 (4a, 4b), a separator 22, 23, and catalyst layers 2a and 2b, gas diffusion layers 4a and 4b, and separators 22 and 23 are laminated in this order on both main surfaces of the electrolyte membrane 1, respectively. In FIG. 5, the same parts as those in FIGS. 5 and FIGS. 1 to 4 have the same functions.

  The separator 22 is for supplying an oxidant gas to the cathode side catalyst electrode 12a, and has an oxidant gas flow path 24 for circulating the oxidant gas. On the other hand, the separator 23 is for supplying fuel to the anode side catalyst electrode 12b, and has a fuel flow path 25 for circulating the fuel.

  The separators 22 and 23 may be made of any material that has stable conductivity even in the environment inside the fuel cell 20. In general, a carbon plate having a flow path is used. Further, the separators 22 and 23 are made of a metal such as stainless steel, and a film made of a conductive material such as chromium, platinum group metal, platinum group metal oxide, or conductive polymer is formed on the surface of the metal. It may be.

  The separators 22 and 23 can function as a current collector when used in a fuel cell in which a plurality of fuel cells 20 are stacked.

<Operating principle of fuel cell>
A fuel capable of supplying hydrogen, such as hydrogen gas or methanol, is supplied to the anode side catalyst electrode 12b through the fuel flow path 25, and protons (H ⁺ ) and electrons (e ⁻ ) are generated from the fuel. The generated protons are conveyed to the cathode side catalyst electrode 12a by the electrolyte membrane 1. On the other hand, an oxidant gas such as air or oxygen gas is supplied to the cathode side catalyst electrode 12a through the oxidant gas flow path 24, and protons carried by the electrolyte membrane 1 and electrons and oxidant gas coming from the external circuit 26 are supplied. Reacts to produce water. In this way, it functions as a fuel cell.

  In the fuel cell 20 according to the present embodiment, the gas diffusion electrode 12 (12a, 12b) and the separators 22 and 23 are respectively formed on both main surfaces of the electrolyte membrane 1 using a known technique used for manufacturing a fuel cell. It can manufacture by laminating sequentially.

  According to the present embodiment, by using a fuel cell catalyst layer having excellent power generation performance at high temperatures and in a non-humidified state, a fuel cell having excellent stability and high performance can be provided.

Hereinafter, the present invention will be described more specifically based on examples. However, the present invention is not limited to these examples, and various modifications can be made without departing from the scope of the present invention.

  Example 1

<Solid acid>
As a solid acid, a metal phosphate (tin phosphate) produced as follows was used. First, 13.56 g (0.09 mol) of tin oxide (SnO ₂ , manufactured by Nano Tec) and 1.40 g (0.0050 mol) of indium oxide (In ₂ O ₃ , manufactured by Nacalai Tesque) were added to dihydrogen phosphate. 27.99 g (0.212 mol) of ammonium (Nacalai Tesque) was added and mixed. Then, the obtained mixture was put into a crucible, fired at about 650 ° C. for about 2 hours, and the product obtained after sintering was pulverized with an agate nail to obtain tin phosphate. The obtained tin phosphate was a pyrophosphate salt partially doped with indium (Sn _0.9 In _0.1 P ₂ O ₇ ).

<Binder>
As a binder, M.I. L. A sulfonated polyetheretherketone (hereinafter also referred to as SPEEK) synthesized as described below based on the method described in Di Vona et al, Polymer 46 (2005), pages 1754-1758 was used.

  A 500 ml round bottom flask equipped with a reflux condenser is charged with 5 g of polyetheretherketone (manufactured by VICTREX, hereinafter also referred to as PEEK) and 250 ml of 96% concentrated sulfuric acid, and kept at 50 ° C. in an oil bath and stirred. The mixture was refluxed for 18 hours. Then, it filtered with the glass filter and wash | cleaned the reaction solid substance with the pure water. Washing was repeated until the filtrate became nearly neutral, then dried at 50 ° C. for 24 hours, and then vacuum dried at 60 ° C. for 6 hours to obtain SPEEK.

  1 g of the obtained SPEEK and 9 g of DMA (N′N-dimethylacetamide) were mixed and stirred at room temperature for about 3 hours to prepare a 10 mass% SPEEK solution.

<Catalyst paste>
To 0.2 g of tin phosphate obtained above, 2 g of ionic liquid, 1.5 g of 85 mass% phosphoric acid aqueous solution (hereinafter also simply referred to as 85% phosphoric acid), platinum-supported carbon (“TEC10E50E”, After adding 1 g of Tanaka Kikinzoku Co., Ltd. and 5 g of water, 4 g of beads were mixed for 24 hours by a planetary ball mill to prepare a catalyst paste. As the ionic liquid, 1-ethyl-3-methylimidazolium bis (fluorosulfonyl) imide (manufactured by Mitsubishi Materials Corporation, hereinafter also referred to as EMIm-SFI) was used.

<Production of gas diffusion electrode>
The catalyst paste obtained above was applied onto a gas diffusion layer (“SGL34BC”, manufactured by SGL Carbon Co., Ltd.) with a blade coater so that the amount of platinum supported was 0.5 mg / cm ^2. The catalyst layer was formed by drying for a minute to obtain a fuel cell gas diffusion electrode.

<Preparation of membrane electrode assembly>
5 g of the 10 mass% SPEEK solution obtained above was added to 5 g of the tin phosphate obtained above, and dispersed with a disperser to prepare an electrolyte paste. The obtained electrolyte paste was coated on a PET film (thickness 50 μm) with a blade coater and dried at about 120 ° C. for about 30 minutes to obtain an electrolyte membrane having a thickness of 70 μm. Next, after peeling the PET film from the obtained electrolyte membrane, the gas diffusion electrode obtained above is placed on both major surfaces of the electrolyte membrane so that the major surface of the catalyst layer and the major surface of the electrolyte membrane are in contact with each other. And the obtained laminate was hot-pressed from both sides under the conditions of 160 ° C. and 3 MPa to obtain a membrane electrode assembly for a fuel cell.

(Example 2)
<Production of gas diffusion electrode and membrane electrode assembly>
Gas diffusion electrode for fuel cell and membrane electrode for fuel cell in the same manner as in Example 1 except that 1-Ethyl-3-methylimidazolium triflate (manufactured by Merck Co., Ltd., hereinafter also referred to as EMIm-TfO) was used as the ionic liquid A joined body was obtained.

(Example 3)
<Production of gas diffusion electrode and membrane electrode assembly>
A gas diffusion electrode for a fuel cell and a fuel cell as in Example 1 except that 1-Ethyl-3-methylimidazolium hydrogensulfate (manufactured by Merck Ltd., hereinafter also referred to as EMIm-HSO ₄ ⁻ ) was used as the ionic liquid. A membrane electrode assembly was obtained.

Example 4
<Solid acid>
As a solid acid, a composite of cesium dihydrogen phosphate (CsH ₂ PO ₄ ) and silicon phosphate (SiP ₂ O ₇ ) prepared as follows (CsH ₂ PO ₄ / SiP ₂ O ₇ ) was used.

First, cesium dihydrogen phosphate (CsH ₂ PO ₄ ) was produced as follows. 28.4 g (0.09 mol) of cesium carbonate (Cs ₂ CO ₃ , manufactured by Aldrich) and 10 g of water were placed in a beaker with a stirrer and stirred with a stirrer. Next, 20.1 g (0.17 mol) of 85% aqueous phosphoric acid solution was added dropwise little by little while stirring with a stirrer. Then, it dried at about 120 degreeC on the hotplate for about 2 hours, and water was evaporated. The obtained product was put into a crucible and dried at about 120 ° C. for about 3 days, and the obtained product was pulverized with an agate nail to obtain cesium dihydrogen phosphate (CsH ₂ PO ₄ ).

Next, silicon phosphate (SiP ₂ O ₇ ) was produced as follows. 8.0 g (0.13 mol) of silicon dioxide (SiO ₂ , manufactured by Tosoh Silica) and 38.4 g (0.33 mol) of 85% by weight aqueous phosphoric acid solution were placed in an agate noodle and mixed until it became a candy-like shape. . The obtained mixture was put into an alumina crucible, calcined at 100 to 200 ° C. for about 60 hours, then calcined at about 700 ° C. for about 4 hours, and the resulting product was pulverized with an agate noodle, Silicon phosphate (SiP ₂ O ₇ ) was obtained.

Finally, 2.0 g (0.0087 mol) of cesium dihydrogen phosphate (CsH ₂ PO ₄ ) obtained above and 3.5 g of silicon phosphate (SiP ₂ O ₇ ) obtained above (0. 017 mol) was dispersed and mixed in a pot mill to obtain a composite of cesium dihydrogen phosphate and silicon phosphate.

<Production of gas diffusion electrode and membrane electrode assembly>
A fuel cell gas diffusion electrode and a fuel cell membrane electrode assembly were obtained in the same manner as in Example 1 except that the composite of cesium dihydrogen phosphate and silicon phosphate obtained above was used as the solid acid.

(Example 5)
<Production of gas diffusion electrode and membrane electrode assembly>
A fuel cell gas diffusion electrode and a fuel cell membrane electrode assembly were obtained in the same manner as in Example 4 except that EMIm-TfO (manufactured by Merck) was used as the ionic liquid.

(Example 6)
<Production of gas diffusion electrode and membrane electrode assembly>
A gas diffusion electrode for a fuel cell and a membrane electrode assembly for a fuel cell were obtained in the same manner as in Example 4 except that EMIm-HSO ₄ ⁻ (Merck Co., Ltd.) was used as the ionic liquid.

(Example 7)
<Catalyst paste>
To 0.2 g of tin phosphate obtained in the same manner as in Example 1, 2 g of ionic liquid (EMIm-SFI, manufactured by Mitsubishi Materials Corporation), 1.5 g of 85 mass% phosphoric acid aqueous solution, and platinum-supported carbon (“ TEC10E50E (manufactured by Tanaka Kikinzoku Co., Ltd.) 1 g, 1.8 g of a 10 mass% SPEEK solution obtained in the same manner as in Example 1, and 5 g of water were added, and then mixed with a planetary ball mill for 4 hours using 4 g of beads. Thus, a catalyst paste was produced.

<Production of gas diffusion electrode and membrane electrode assembly>
A gas diffusion electrode for a fuel cell and a membrane electrode assembly for a fuel cell were obtained in the same manner as in Example 1 except that the catalyst paste obtained above was used.

(Example 8)
<Production of gas diffusion electrode and membrane electrode assembly>
A gas diffusion electrode for a fuel cell and a membrane electrode assembly for a fuel cell were obtained in the same manner as in Example 7 except that EMIm-TfO (manufactured by Merck) was used as the ionic liquid.

Example 9
<Production of gas diffusion electrode and membrane electrode assembly>
A gas diffusion electrode for a fuel cell and a membrane electrode assembly for a fuel cell were obtained in the same manner as in Example 7 except that EMIm-HSO ₄ ⁻ (Merck Co., Ltd.) was used as the ionic liquid.

(Example 10)
<Catalyst paste>
Into 0.2 g of the complex of cesium dihydrogen phosphate and silicon phosphate obtained in the same manner as in Example 4, 2 g of ionic liquid (EMIm-SFI, manufactured by Mitsubishi Materials Corporation) and 85 mass% phosphoric acid aqueous solution 1 5 g, 1 g of platinum-supporting carbon (“TEC10E50E”, manufactured by Tanaka Kikinzoku Co., Ltd.), 1.8 g of a 10 mass% SPEEK solution obtained in the same manner as in Example 1, and 5 g of water were added, and then 4 g of beads were added. The catalyst paste was prepared by mixing with a planetary ball mill for about 24 hours.

<Production of gas diffusion electrode and membrane electrode assembly>
A gas diffusion electrode for a fuel cell and a membrane electrode assembly for a fuel cell were obtained in the same manner as in Example 1 except that the catalyst paste obtained above was used.

(Example 11)
<Production of gas diffusion electrode and membrane electrode assembly>
A fuel cell gas diffusion electrode and a fuel cell membrane electrode assembly were obtained in the same manner as in Example 10 except that EMIm-TfO (manufactured by Merck) was used as the ionic liquid.

(Example 12)
<Production of gas diffusion electrode and membrane electrode assembly>
A fuel cell gas diffusion electrode and a fuel cell membrane electrode assembly were obtained in the same manner as in Example 10 except that EMIm-HSO ₄ ⁻ (manufactured by Merck) was used as the ionic liquid.

<Production of gas diffusion electrode and membrane electrode assembly>
A gas diffusion electrode for a fuel cell and a membrane electrode assembly for a fuel cell were obtained in the same manner as in Example 1 except that the catalyst paste obtained above was used.

(Example 13)
<Catalyst paste>
0.2 g of tin phosphate obtained in the same manner as in Example 1, 2 g of ionic liquid (EMIm-SFI, manufactured by Mitsubishi Materials Corporation), 1 g of platinum-supported carbon (“TEC10E50E”, manufactured by Tanaka Kikinzoku Co., Ltd.), After adding 5 g of water, 4 g of beads were mixed with a planetary ball mill for about 24 hours to prepare a catalyst paste.

<Production of gas diffusion electrode>
The catalyst paste obtained above was applied onto a gas diffusion layer (“SGL34BC”, manufactured by SGL Carbon Co., Ltd.) with a blade coater so that the amount of platinum supported was 0.5 mg / cm ^2. After drying for a minute to form a catalyst layer, 1.5 g of 85 mass% phosphoric acid aqueous solution was applied on the main surface of the catalyst layer to obtain a gas diffusion electrode for a fuel cell.

<Preparation of membrane electrode assembly>
A membrane electrode assembly for a fuel cell was produced in the same manner as in Example 1 except that the gas diffusion electrode obtained above was used.

(Example 14)
<Catalyst paste>
To 0.2 g of tin phosphate obtained in the same manner as in Example 1, 1.5 g of 85 mass% phosphoric acid aqueous solution, 1 g of platinum-supporting carbon (“TEC10E50E”, manufactured by Tanaka Kikinzoku Co., Ltd.) and 5 g of water were added. Thereafter, 4 g of beads were mixed for about 24 hours by a planetary ball mill to prepare a catalyst paste.

<Production of gas diffusion electrode>
The catalyst paste obtained above was applied onto a gas diffusion layer (“SGL34BC”, manufactured by SGL Carbon Co., Ltd.) with a blade coater so that the amount of platinum supported was 0.5 mg / cm ^2. After drying for a minute to form a catalyst layer, 2 g of ionic liquid (EMIm-SFI, manufactured by Mitsubishi Materials Corporation) was applied on the main surface of the catalyst layer to obtain a fuel cell gas diffusion electrode.

<Preparation of membrane electrode assembly>
A membrane electrode assembly for a fuel cell was produced in the same manner as in Example 1 except that the gas diffusion electrode obtained above was used.

(Example 15)
<Catalyst paste>
To 0.2 g of tin phosphate obtained in the same manner as in Example 1, 1 g of platinum-supporting carbon (“TEC10E50E” manufactured by Tanaka Kikinzoku Co., Ltd.) and 5 g of water were added, and then 4 g of beads were used to measure about The catalyst paste was produced by mixing for 24 hours.

<Production of gas diffusion electrode>
The catalyst paste obtained above was applied onto a gas diffusion layer (“SGL34BC”, manufactured by SGL Carbon Co., Ltd.) with a blade coater so that the amount of platinum supported was 0.5 mg / cm ^2. After forming the catalyst layer by drying for a minute, 1.5 g of 85 mass% phosphoric acid aqueous solution and 2 g of ionic liquid (EMIm-SFI, manufactured by Mitsubishi Materials Corporation) are applied on the main surface of the catalyst layer, and the fuel cell gas A diffusion electrode was obtained.

<Preparation of membrane electrode assembly>
A membrane electrode assembly for a fuel cell was produced in the same manner as in Example 1 except that the gas diffusion electrode obtained above was used.

(Comparative Example 1)
<Catalyst paste>
After adding 1 g of platinum-supported carbon (TEC10E50E, manufactured by Tanaka Kikinzoku Co., Ltd.) and 5 g of water to 3.5 g of ionic liquid (EMIm-SFI, manufactured by Mitsubishi Materials Co., Ltd.) The catalyst paste was produced by mixing for 24 hours.

<Production of gas diffusion electrode and membrane electrode assembly>
A gas diffusion electrode for a fuel cell and a membrane electrode assembly for a fuel cell were obtained in the same manner as in Example 1 except that the catalyst paste obtained above was used.

(Comparative Example 2)
<Catalyst paste>
3.5 g of ionic liquid (EMIm-SFI, manufactured by Mitsubishi Materials Corporation), 1 g of platinum-supported carbon (“TEC10E50E”, manufactured by Tanaka Kikinzoku Co., Ltd.) and 10% by mass SPEEK solution 1 obtained in the same manner as in Example 1. After adding 8 g and 5 g of water, 4 g of beads were mixed with a planetary ball mill for about 24 hours to prepare a catalyst paste.

<Production of gas diffusion electrode and membrane electrode assembly>
A gas diffusion electrode for a fuel cell and a membrane electrode assembly for a fuel cell were obtained in the same manner as in Example 1 except that the catalyst paste obtained above was used.

(Comparative Example 3)
<Catalyst paste>
0.2 g of tin phosphate obtained in the same manner as in Example 1, 3.5 g of ionic liquid (EMIm-SFI, manufactured by Mitsubishi Materials Corporation), and 1 g of platinum-supported carbon (“TEC10E50E”, manufactured by Tanaka Kikinzoku Co., Ltd.) After adding 5 g of water, 4 g of beads were mixed for about 24 hours by a planetary ball mill to prepare a catalyst paste.

<Production of gas diffusion electrode and membrane electrode assembly>
A gas diffusion electrode for a fuel cell and a membrane electrode assembly for a fuel cell were obtained in the same manner as in Example 1 except that the catalyst paste obtained above was used.

(Comparative Example 4)
<Catalyst paste>
0.2 g of tin phosphate obtained in the same manner as in Example 1, 3.5 g of ionic liquid (EMIm-SFI, manufactured by Mitsubishi Materials Corporation), and 1 g of platinum-supported carbon (“TEC10E50E”, manufactured by Tanaka Kikinzoku Co., Ltd.) Then, after adding 1.8 g of 10 mass% SPEEK solution obtained in the same manner as in Example 1 and 5 g of water, 4 g of beads were mixed by a planetary ball mill for about 24 hours to prepare a catalyst paste.

<Production of gas diffusion electrode and membrane electrode assembly>
A gas diffusion electrode for a fuel cell and a membrane electrode assembly for a fuel cell were obtained in the same manner as in Example 1 except that the catalyst paste obtained above was used.

(Comparative Example 5)
<Catalyst paste>
After adding 0.2 g of 85 mass% phosphoric acid aqueous solution, 1 g of platinum-supporting carbon (“TEC10E50E”, Tanaka Kikinzoku Co., Ltd.) and 5 g of water to 0.2 g of tin phosphate obtained in the same manner as in Example 1, 4 g of beads were mixed for about 24 hours by a planetary ball mill to prepare a catalyst paste.

<Production of gas diffusion electrode and membrane electrode assembly>
A gas diffusion electrode for a fuel cell and a membrane electrode assembly for a fuel cell were obtained in the same manner as in Example 1 except that the catalyst paste obtained above was used.

(Comparative Example 6)
<Catalyst paste>
0.2 g of tin phosphate obtained in the same manner as in Example 1, 1.5 g of 85 mass% phosphoric acid aqueous solution, 1 g of platinum-supporting carbon (“TEC10E50E”, manufactured by Tanaka Kikinzoku Co., Ltd.), and the same as in Example 1 After adding 1.8 g of the 10% by mass SPEEK solution obtained in the above and 5 g of water, the mixture was mixed for about 24 hours with a planetary ball mill using 4 g of beads to prepare a catalyst paste.

<Production of gas diffusion electrode and membrane electrode assembly>
A gas diffusion electrode for a fuel cell and a membrane electrode assembly for a fuel cell were obtained in the same manner as in Example 1 except that the catalyst paste obtained above was used.

(Measurement of electromotive force)
The resulting fuel cell membrane electrode assembly in Examples and Comparative Examples, were assembled cell JARI standard cell, a current under 160 ° C. and no humidity atmosphere - performs voltage (IV) measurements, caused in 100 mA / cm ² The power (V) was measured, and the results are shown in Tables 1 to 4 below. Here, the JARI cell standard cell is used for the basic research of PEFC and the evaluation test of PEFC materials (membranes, electrode catalysts, components, etc.) at the Japan Automobile Research Institute (JARI). Means a cell developed as Tables 1 to 4 also show electrolytes contained in the catalyst layer.

As can be seen from Tables 1 to 4, the membrane electrode assemblies for fuel cells of Examples 1 to 15 in which the catalyst layer contains a solid acid, an ionic liquid, and phosphoric acids as an electrolyte, the catalyst layer contains only an ionic liquid as an electrolyte. The fuel cell membrane electrode assemblies of Comparative Examples 1 and 2 and the catalyst layer containing ionic liquid and solid acid as electrolytes and the fuel cell membrane electrode assemblies and catalyst layers of Comparative Examples 3 to 4 containing phosphoric acids as electrolytes The electromotive force at 100 mA / cm ² was higher at 160 ° C. and in a non-humidified atmosphere as compared with the fuel cell membrane electrode assemblies of Comparative Examples 5 to 6 containing the solid acid. That is, in the fuel cell membrane electrode assemblies of Examples 1 to 15, the proton conductivity in the catalyst layer is high and the cell performance is excellent. On the other hand, in the fuel cell membrane electrode assemblies of Comparative Examples 1 to 6, the catalyst The proton conduction path in the layer does not work well and the battery performance is degraded.

  The present invention can be suitably applied to a technical field related to a catalyst layer containing an electrolyte and a fuel cell using the same.

DESCRIPTION OF SYMBOLS 1 Electrolyte membrane 2, 2a, 2b Catalyst layer 4, 4a, 4b Gas diffusion layer 7 Base material 11 Fuel cell catalyst layer with a base material 12, 12a, 12b Fuel cell gas diffusion electrode 13 Fuel cell catalyst layer-electrolyte membrane Laminated body 14 Electrode assembly for fuel cell 12a Cathode side catalyst electrode 12b Anode side catalyst electrode 20 Fuel cell 22, 23 Separator 24 Oxidant gas flow path 25 Fuel flow path 26 External circuit

Claims (8)

A fuel cell catalyst layer comprising an electrolyte and a catalyst,
The fuel cell catalyst layer, wherein the electrolyte contains an ionic liquid, a solid acid, and phosphoric acids. The catalyst layer for a fuel cell according to claim 1, wherein the solid acid is a metal phosphate represented by the following general formula (1).
M _1-x D _x P ₂ O ₇ (1)
However, in the general formula (1), X is 0 ≦ X <0.5, and M is Zr, Cs, Sn, Ti, Si, Ge, Pb, Hf, Ca, Mg, W, Na, and Al. D is a kind selected from the group consisting of Al, In, B, Ga, Sc, Yb, Ce, La, Sb, Y, Nb and Mg. A fuel cell catalyst layer according to claim 1 or 2, and a substrate.
The catalyst layer for a fuel cell with a substrate, wherein the catalyst layer is formed on one main surface of the substrate. A fuel cell catalyst layer according to claim 1 or 2, and a gas diffusion layer,
The gas diffusion electrode for a fuel cell, wherein the catalyst layer is disposed on one main surface of the gas diffusion layer. A fuel cell catalyst layer according to claim 1 or 2, and an electrolyte membrane,
A catalyst layer-electrolyte membrane laminate for a fuel cell, wherein the catalyst layer is disposed on at least one main surface of the electrolyte membrane. A fuel cell catalyst layer according to claim 1, comprising an electrolyte membrane and a gas diffusion layer,
The membrane electrode assembly for a fuel cell, wherein the catalyst layer and the gas diffusion layer are laminated in this order on both main surfaces of the electrolyte membrane. A catalyst layer for a fuel cell according to claim 1, an electrolyte membrane, a gas diffusion layer, and a separator,
The fuel cell, wherein the catalyst layer, the gas diffusion layer, and the separator are respectively laminated in this order on both main surfaces of the electrolyte membrane. A method for producing a fuel cell catalyst layer comprising an electrolyte and a catalyst,
Forming a catalyst layer using a catalyst layer forming composition containing an electrolyte and a catalyst,
Including a solid acid, an ionic liquid, and phosphoric acids as an electrolyte in the catalyst layer forming composition, or
In the case where the composition for forming a catalyst layer does not contain one or more electrolytes selected from the group consisting of an ionic liquid and phosphoric acids, the catalyst layer formed using the composition for forming a catalyst layer is converted from an ionic liquid and phosphoric acids. By applying one or more electrolytes selected from the group consisting of
A method for producing a fuel cell catalyst layer, comprising obtaining a catalyst layer containing an ionic liquid, a solid acid, and phosphoric acids as an electrolyte.

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