JP2015093223A - Oxide based non-platinum catalyst granules, manufacturing method of oxide based non-platinum catalyst granules, and catalyst ink and fuel cell using the oxide based non-platinum catalyst granules - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oxide based non-platinum catalyst granules without problems in use of oxide based non-platinum catalysts including no precious metal such as poor power generation characteristics per unit area due to low conductivity when used in a fuel cell and poor production efficiency in a process for manufacturing a catalyst ink; a manufacturing method thereof; and a catalyst ink and a fuel cell using the oxide based non-platinum catalyst granules.SOLUTION: The oxide based non-platinum catalyst granules include an oxide based non-platinum catalyst, a conductive carbon material, and a dispersant, having a spherical or elliptical shape, with an average particle diameter of 0.5 to 100 μm.

Description

  The present invention relates to an oxide-based non-platinum catalyst granule that does not support a noble metal such as platinum or a platinum alloy, a method for producing the oxide-based non-platinum catalyst granule, and the oxide-based non-platinum catalyst granule. The present invention relates to a catalyst ink and a fuel cell.

  A fuel cell is a system that can directly convert chemical energy into electrical energy using an electrochemical system, and is expected to be a next-generation energy because of its high efficiency. In particular, solid polymer fuel cells are being actively developed for automobiles, stationary devices, and small mobile devices. Conventionally, platinum-based catalysts using platinum or platinum alloys having high oxygen reduction activity have been used as electrode catalysts for these polymer electrolyte fuel cells. However, in terms of cost, resource amount, and supply stability, Therefore, development of catalysts other than platinum-based catalysts (referred to as non-platinum-based catalysts) has been demanded. However, the performance of current non-platinum-based catalysts is not sufficient compared to platinum-based catalysts. Therefore, there is technology development to improve the performance of catalysts that significantly reduce the amount of platinum used or non-platinum-based catalysts that do not use platinum. It is being advanced. As non-platinum-based catalysts, carbon catalysts doped with nitrogen, transition metal oxides, and the like are attracting attention. (Non-Patent Document 1, Patent Documents 1-5, etc.)

  In particular, oxide-based non-platinum catalysts are being actively developed because they are more economical and cost superior than platinum-based catalysts. However, its performance is not yet sufficient, and in order to obtain battery performance close to that of a platinum-based catalyst, it is necessary to improve the current value, and for that purpose, it is necessary to improve the conductivity of the film. For this reason, studies have been made to use a conductive substance as a catalyst carrier or to add a conductive auxiliary agent when preparing a catalyst ink. However, when a conductive material is added at the time of catalyst ink, transition metal oxides and conductive assistants tend to cause aggregation. When these compositions are applied, pinholes may occur in the coating when the catalyst is aggregated. There is a problem that an electrode film having uniform conductivity, proton conductivity and gas diffusibility in the coating film cannot be obtained, resulting in a decrease in current amount and a decrease in electromotive force. Although there is such a technical problem, no means for solving this has been found.

JP 2011-6283 A JP 2008-282725 A JP 2009-295441 A JP 2009-148706 A International Publication No. 2012/128287 Pamphlet

SCIENCE (VOL.332, pp.443-447, 2011)

  The problem to be solved by the present invention is that the power generation characteristics per unit area when producing a fuel cell due to low conductivity, which is a problem when an oxide-based non-platinum catalyst is used as an electrode catalyst, and a catalyst ink Oxide-based non-platinum catalyst granules that can solve problems such as poor dispersibility and poor coating efficiency (coating unevenness and pinholes) generated in the production process, and It is an object of the present invention to provide a production method, and further a catalyst ink using the oxide-based non-platinum catalyst granule and a fuel cell.

  That is, the present invention is an oxide-based non-platinum catalyst granule containing an oxide-based non-platinum catalyst, a conductive carbon material and a dispersant, and the shape of the oxide-based non-platinum catalyst granule. However, the present invention relates to an oxide-based non-platinum catalyst granule having a spherical or ellipsoidal shape and an average particle diameter of the granule of 0.5 to 100 μm.

  The present invention also relates to an oxide-based non-platinum catalyst granule in which the oxide-based non-platinum catalyst contains at least one element selected from the group consisting of Ti, Zr, Nb, V, Mo, W and Ta. .

  Moreover, this invention has the process 1 which wet-mixes an oxide type non platinum catalyst, a conductive carbon material, and a dispersing agent, and the process 2 which spray-drys and granulates the paste obtained by the said mixing. The present invention relates to a method for producing a characteristic oxide-based non-platinum catalyst granule.

  The present invention also relates to an oxide-based non-platinum catalyst granule produced by the method described above.

  The present invention also relates to a catalyst ink containing the oxide-based non-platinum catalyst granule described above, a binder, and a solvent.

  The present invention also relates to a fuel cell having an electrode catalyst in which the oxide-based non-platinum catalyst is bonded to one or both surfaces of a solid polymer electrolyte membrane.

  According to the present invention, a spherical or ellipsoidal oxide-based non-platinum catalyst granule having an average particle diameter of 0.5 to 100 μm and high conductivity can be obtained. By using the oxide-based non-platinum catalyst granule, a catalyst ink that can be easily dispersed in a solvent with a small amount of a binder component and has a high concentration and high dispersion stability can be produced. Furthermore, the catalyst ink can achieve improvement in electrode conductivity, and a fuel cell having high power generation characteristics can be obtained.

The oxide-based non-platinum catalyst granule according to the present invention is a granule containing an oxide-based non-platinum catalyst, a conductive carbon material, and a dispersant.
The granulated material here means that a fine oxide-based non-platinum catalyst and a conductive carbon material are uniformly distributed in the granulated material at the primary particle level by the dispersant used when producing the granulated material. A single lump is formed with a spherical or ellipsoidal shape.
In the oxide-based non-platinum catalyst granule according to the present invention, the oxide-based non-platinum catalyst and the conductive carbon material are uniformly contacted and combined, so that the electrons necessary for the oxygen reduction reaction are efficiently conveyed to the active site. It becomes possible. Further, since secondary particles having a uniform particle diameter are formed by the granulation treatment, it is possible to produce an oxide-based non-platinum catalyst having good dispersibility in a solvent and high density.

  The oxide-based non-platinum catalyst granule in the present invention preferably has a spherical or ellipsoidal shape with an average particle diameter of 0.5 to 100 μm, preferably 1 to 50 μm.

The spherical or ellipsoidal shape of the granule is easy to handle as an oxide-based non-platinum catalyst powder, and not only dispersibility in a solvent is improved, but also a limited volume catalyst layer, fuel cell When the maximum amount of oxide-based non-platinum catalyst is to be filled, the shape can be filled efficiently.
The spherical shape or the ellipsoidal shape here is preferably 0.5 or more, more preferably 0.7 or more, and more preferably 0.9 or more, when expressed in terms of sphericity. It is particularly preferred. The sphericity in the present invention refers to the average value of 100 particles arbitrarily selected for the obtained minor axis / major axis by observing the shape of the particle with a scanning electron microscope and measuring the minor axis and major axis. Say what you asked for.

<Oxide-based non-platinum catalyst>
The oxide-based non-platinum catalyst in the present invention is oxide particles containing a transition metal and an oxygen element as main components, and conventionally known ones can be used. Control of the crystal structure of oxide particles, introduction of oxygen vacancies, doping of different elements such as nitrogen, and finer particle size are effective in improving catalytic properties such as oxygen adsorption capacity and electron conductivity, It is important to develop high oxygen reduction ability.

  The oxide-based non-platinum catalyst in the present invention is at least one selected from the group consisting of Zr, Ta, Ti, Nb, V, Fe, Mn, Co, Ni, Cu, Zn, Cr, W, and Mo. These transition metal elements can be used, more preferably oxycarbonitrides of these transition metal elements.

Composition formula of the oxide-based non-platinum catalysts are, for example, M1C _p N _q O _r (although, M1 is a transition metal element, p, q, r represents the ratio of the number of atoms, 0 ≦ p ≦ 3, 0 ≦ q ≦ 2, 0 <r ≦ 3), M2 _a M3 _b C _x N _y O _z (where M2 is Zr, Ta, Ti, Nb, V, Fe, Mn, Co, Ni, One metal selected from the group consisting of Cu, Zn, Cr, W, and Mo, and M2 is at least one metal different from M1 selected from the group a, b, x. , Y, z represent the ratio of the number of atoms, 0.5 ≦ a <1, 0 <b ≦ 0.5, 0 <x ≦ 3, 0 <y ≦ 2, 0 <z ≦ 3, and a + b = 1 It is expressed by. Moreover, the catalyst which compounded these compounds and electroconductive compounds can also be used conveniently.
Further, the composition ratio of the oxide-based non-platinum catalyst _{used, M1C p N q O r (} 0.5 ≦ p ≦ 2,0.5 ≦ q ≦ 1,0 <r ≦ 3) are preferred, Ti, Zr, Nb, It is preferable to contain at least one element selected from the group consisting of V, Mo, W and Ta.

<Conductive carbon material>
The conductive carbon material is not particularly limited as long as it is a conductive carbon material, but carbon black, graphite, conductive carbon fiber (carbon nanotube, carbon nanofiber, carbon fiber, carbon nanohorn), graphene , Graphene nanoplatelets, fullerenes and the like can be used alone or in combination of two or more. From the viewpoint of conductivity, availability, and cost, it is preferable to use carbon black.

  Carbon black is a furnace black produced by continuously pyrolyzing a gas or liquid raw material in a reactor, especially ketjen black using ethylene heavy oil as a raw material. Channel black that has been rapidly cooled and precipitated, thermal black obtained by periodically repeating combustion and thermal decomposition using gas as a raw material, and particularly various types such as acetylene black using acetylene gas as a raw material, or 2 More than one type can be used in combination. Ordinarily oxidized carbon black, hollow carbon and the like can also be used.

As the specific surface area of the carbon black used increases, the number of contact points between the carbon black particles increases, which is advantageous in reducing the internal resistance of the electrode. Specifically, the specific surface area (BET) determined from the amount of nitrogen adsorbed is 20 m ² / g or more and 1500 m ² / g or less, preferably 50 m ² / g or more and 1500 m ² / g or less, more preferably 100 m ^2. / G or more and 1500 m ² / g or less are desirable. If carbon black having a specific surface area of less than 20 m ² / g is used, it may be difficult to obtain sufficient conductivity, and carbon black of more than 1500 m ² / g may be difficult to obtain from commercially available materials. is there.

  Further, the particle size of the carbon black to be used is preferably 0.005 to 1 μm, particularly preferably 0.01 to 0.2 μm in terms of primary particle size. However, the primary particle diameter here is an average of the particle diameters measured with an electron microscope.

  The dispersed particle size of the conductive carbon material in the composition for forming a fuel cell electrode is desirably refined to 0.03 μm or more and 5 μm or less. A composition having a conductive carbon material with a dispersed particle size of less than 0.03 μm may be difficult to produce. Further, when a composition having a dispersed particle size of the conductive carbon material exceeding 5 μm is used, there may be problems such as variations in the material distribution of the catalyst layer and variations in the resistance distribution of the electrodes.

  The dispersed particle size referred to here is a particle size (D50) that is 50% when the volume ratio of the particles is integrated from the fine particle size distribution in the volume particle size distribution. A particle size distribution meter such as a dynamic light scattering type particle size distribution meter ("Microtrack UPA" manufactured by Nikkiso Co., Ltd.).

  Examples of commercially available carbon black include Toka Black # 4300, # 4400, # 4500, # 5500 (Tokai Carbon Co., Furnace Black), Printex L and the like (Degussa Co., Furnace Black), Raven 7000, 5750, 5250, 5000 ULTRA III, 5000 ULTRA, etc., Conductex SC ULTRA, Conductex 975 ULTRA, etc., PUER BLACK100, 115, 205, etc. (manufactured by Colombian, furnace black), # 2350, # 2400B, # 2600B, # 30050B, # 3030B, # 3030B, # 3030B # 3350B, # 3400B, # 5400B etc. (Mitsubishi Chemical Co., Furnace Black), MONARCH1400, 1300, 900, VulcanXC- 2R, BlackPearls2000, etc. (Cabot, Furnace Black), Ensaco 250G, Ensaco 260G, Ensaco 350G, SuperP-Li (manufactured by TIMCAL), Ketjen Black EC-300J, EC-600JD (manufactured by Akzo), Denka Black, Denka Black HS Examples of graphite such as -100, FX-35 (manufactured by Denki Kagaku Kogyo Co., Ltd., acetylene black) include natural graphite such as artificial graphite, flake graphite, massive graphite, and earth graphite, but are not limited thereto. They may be used in combination of two or more.

  As the conductive carbon fibers, those obtained by firing from petroleum-derived raw materials are preferable, but those obtained by firing from plant-derived raw materials can also be used. For example, VGCF manufactured by Showa Denko Co., Ltd. manufactured with petroleum-derived raw materials can be mentioned.

  Examples of commercially available graphene-based materials include graphene nanoplatelets manufactured by XGSciences such as xGnP-C-750 and xGnP-M-5.

<Dispersant>
The dispersant serves to uniformly disperse the oxide-based non-platinum catalyst and the conductive carbon material in the solvent. In particular, conductive carbon materials generally have a small particle diameter, a large surface area, and secondary particles are strongly bonded to each other, such as carbon black, and can be dispersed in a solvent without a dispersant. It is extremely difficult and the presence of a dispersant is essential. The dispersant is preferably adsorbed on the surface at the primary particle level of the oxide-based non-platinum catalyst and the conductive carbon material.

  The dispersant is not particularly limited as long as the oxide-based non-platinum catalyst and the conductive carbon material can be dispersed. The resin having a basic functional group, the resin having an acidic functional group, and the pigment having a basic functional group Derivatives, pigment derivatives having an acidic functional group, and the like can be preferably used. For example, an acidic functional group such as a sulfonic acid group, a carboxylic acid group, a phosphoric acid group, and a hydroxyl group, or an amino group that is a basic functional group can be used.

As the dispersant, either an aqueous system or a solvent system can be used. Specific examples include the following.
[Aqueous dispersant]
Although it does not specifically limit as a commercially available dispersing agent for water systems, For example, the following are mentioned.

  Examples of the dispersant manufactured by Big Chemie include Disperbyk, Disperbyk-180, 183, 184, 185, 187, 190, 191, 192, 193, 2090, 2091, 2095, 2096, and BYK-154.

  Examples of the dispersant manufactured by Nippon Lubrizol include SOLPERSE 12000, 20000, 27000, 41000, 41090, 43000, 44000, or 45000.

  Examples of the dispersant manufactured by Efka Additives include EFKA1101, 1120, 1125, 1500, 1503, 4500, 4510, 4520, 4530, 4540, 4550, 4560, 4570, 4580, and 5071.

  As the dispersant manufactured by BASF Japan, JONCRYL67, 678, 586, 611, 680, 682, 683, 690, 52J, 57J, 60J, 61J, 62J, 63J, 70J, HPD-96J, 501J, 354J, 6610, PDX-6102B, 7100, 390, 711, 511, 7001, 741, 450, 840, 74J, HRC-1645J, 734, 852, 7600, 775, 537J, 1535, PDX-7630, 352J, 252D, 538J, 7640, 7641, 631, 790, 780, 7610, JDX-C3000, JDX-3020, JDX-6500, etc. are mentioned.

  Examples of the dispersant manufactured by Kawaken Fine Chemicals include Hinoact A-110, 300, 303, or 501.

  Examples of the dispersant manufactured by Nitto Bo Medical include PAA series, PAS series, amphoteric series PAS-410C, 410SA, 84, 2451, or 2351.

  Examples of the dispersant manufactured by ISP Japan include polyvinylpyrrolidone PVP K-15, K-30, K-60, K-90, or K-120.

  Examples of the dispersant manufactured by BASF Japan include Luvitec K17, K30, K60, K80, K85, K90, K115, VA64W, VA64, VPI55K72W, or VPC55K65W.

  Examples of the dispersant manufactured by Maruzen Petrochemical Co., Ltd. include polyvinylimidazole PVI.

  Examples of the dispersant manufactured by Nippon Steel Mining Co., Ltd. include iron phthalocyanine derivatives (ammonium sulfonate).

[Solvent dispersant]
Although it does not specifically limit as a commercially available dispersing agent for solvents, For example, the following are mentioned.

  As a dispersing agent made by Big Chemie, Anti-Terra-U, U100, 203, 204, 205, Disperbyk-101, 102, 103, 106, 107, 108, 109, 110, 111, 112, 116, 130, 140 142, 161, 162, 163, 164, 166, 167, 168, 170, 171, 174, 180, 182, 183, 184, 185, 2000, 2001, 2050, 2070, 2096, 2150, BYK-P104, P104S , P105, 9076, 9077, and 220S.

  As a dispersant manufactured by Nippon Lubrizol Corporation, SOLPERSE 3000, 5000, 9000, 13240, 13650, 13940, 17000, 18000, 19000, 21000, 22000, 24000SC, 24000GR, 26000, 28000, 31845, 32000, 32500, 32600, 33500 34750, 35100, 35200, 36600, 37500, 38500, or 53095.

  As the dispersant manufactured by Efka Additives, EFKA 1500, 1501, 1502, 1503, 4008, 4009, 4010, 4015, 4020, 4046, 4047, 4050, 4055, 4060, 4080, 4300, 4330, 4400, 4401, 4402, 4403, 4406, 4510, 4520, 4530, 4570, 4800, 5010, 5044, 5054, 5055, 5063, 5064, 5065, 5066, 5070, 5071, 5207, 5244, and the like.

  Examples of the dispersant manufactured by Ajinomoto Fine-Techno Co., Ltd. include Addisper PB711, PB821, PB822, PN411, or PA111.

  Examples of the dispersant manufactured by Kawaken Fine Chemicals include Hinoact KF-1000, 1300M, 1500, 1700, T-6000, 8000, 8000E, or 9100.

  Examples of the dispersant manufactured by BASF Japan include Luvicap and the like.

<Method for producing oxide-based non-platinum catalyst granulation>
The production method of the oxide-based non-platinum catalyst granule in the present invention is not particularly limited, but as a preferred production method, step 1 of wet-mixing the oxide-based non-platinum catalyst, the conductive carbon material and the dispersant, And a step 2 of spray-drying and granulating the paste obtained by the mixing.

  The ratio of the oxide-based non-platinum catalyst and the conductive carbon material constituting the oxide-based non-platinum catalyst granule in the present invention is not particularly limited. For example, for forming the fuel cell electrode of the present invention In the composition, the conductive carbon material is not particularly defined with respect to 100 parts by weight of the oxide-based non-platinum catalyst, but 1 to 500 parts by weight, preferably 10 to 300 parts by weight, and the dispersant is 0.01 to 25 parts. Parts by weight, preferably 0.02 to 10 parts by weight. When the conductive carbon material exceeds 500 parts by weight with respect to 100 parts by weight of the oxide-based non-platinum catalyst, the content of the oxide-based non-platinum catalyst in the catalyst layer becomes too small, and the practicality is reduced in terms of power generation characteristics. . On the other hand, when the dispersant is less than 0.01 parts by weight with respect to 100 parts by weight of the oxide-based non-platinum catalyst, the amount of the dispersant is insufficient with respect to the surface of the oxide-based non-platinum catalyst to be uniformly dispersed. It may become difficult to obtain a body, and as a result, it may be difficult to obtain a uniform granulated body.

  The following apparatus can be used as the wet mixing apparatus.

As a wet mixing device, for example,
Mixers such as dispersers, homomixers, or planetary mixers:
Homogenizers such as “Clairemix” manufactured by M Technique or “Fillmix” manufactured by PRIMIX:
Media type dispersers such as paint conditioners (manufactured by Red Devil), ball mills, sand mills (such as “Dynomill” manufactured by Shinmaru Enterprises), attritors, pearl mills (such as “DCP mill” manufactured by Eirich), or coball mills:
Wet jet mill (“Genus PY” manufactured by Genus, “Starburst” manufactured by Sugino Machine, “Nanomizer” manufactured by Nanomizer, etc.) “Claire SS-5” manufactured by M Technique, or “Micro” manufactured by Nara Machinery Co., Ltd. Medialess dispersers such as
Other examples include, but are not limited to, roll mills and kneaders. Moreover, it is preferable to use what performed the metal mixing prevention process from an apparatus as a wet mixing apparatus.

  For example, when using a media-type disperser, a disperser in which the agitator and vessel are made of a ceramic or resin disperser, or the surface of the metal agitator and vessel is treated with tungsten carbide spraying or resin coating. Is preferably used. And as a medium, it is preferable to use ceramic beads, such as glass beads, zirconia beads, or alumina beads. Moreover, also when using a roll mill, it is preferable to use a ceramic roll. Only one type of dispersion device may be used, or a plurality of types of devices may be used in combination.

In the method for producing an oxide-based non-platinum catalyst granule in the present invention, a spray dryer such as a spray dryer can be used in the method of spray drying and granulating the mixed paste in step 2.
Specifically, the solvent may be volatilized and removed while spraying the mixed paste in the form of a mist. Spray conditions and solvent volatilization conditions can be selected as appropriate.

<Catalyst ink>
Next, the catalyst ink using the oxide-based non-platinum catalyst granule in the present invention will be described.
The catalyst ink of the present invention contains at least an oxide-based non-platinum catalyst granule, a binder, and a solvent. The binder is preferably a material having proton conductivity and oxidation resistance. The proportions of the oxide-based non-platinum catalyst granule, the binder, and the solvent are not particularly limited, and are appropriately selected within a wide range.

  The ratio of the oxide-based non-platinum catalyst granule and the binder contained in the catalyst ink of the present invention is not particularly limited, but preferably, the amount of binder added is the oxide-based non-platinum catalyst granulation The amount is 10 to 300 parts by weight, preferably 20 to 250 parts by weight, based on 100 parts by weight of the body.

Furthermore, in the catalyst ink in the present invention, a dispersant may be used in order to improve wettability and dispersibility of the oxide-based non-platinum catalyst granule in a solvent.
Content of a dispersing agent is 0.01 to 5 weight% with respect to the oxide type non-platinum catalyst granule in catalyst ink, Preferably it is 0.02 to 3 weight%. By setting the content in this range, the dispersion stability of the oxide-based non-platinum catalyst granule can be sufficiently achieved, and at the same time, the aggregation of the oxide-based non-platinum catalyst granule can be effectively prevented, and Precipitation of the dispersant on the surface of the catalyst layer can be prevented.

  In addition, the oxide-based non-platinum catalyst granule in the present invention has a spherical or ellipsoidal shape and an average particle size of 0.5 to 100 μm, which is a relatively large granule. It is easy to increase the concentration of oxide-based non-platinum catalyst granules in the ink. Therefore, the oxide-based non-platinum catalyst granule concentration in the ink can be 20 to 50% by weight by optimizing the ink formulation, and can be easily produced when it is desired to increase the thickness of the catalyst layer.

  The method for preparing the catalyst ink is not particularly limited. In the preparation, each component may be dispersed at the same time, or the oxide-based non-platinum catalyst granule may be dispersed only with a dispersant, and then a binder may be added. , And can be optimized by binder and solvent type.

  The apparatus for dispersing and mixing the oxide-based non-platinum catalyst granule and the binder in a solvent is not particularly limited. However, the homogenizer or medialess device is difficult to destroy the oxide-based non-platinum catalyst granulated material during dispersion mixing. A dispersion device is preferred.

<Binder>
As the binder, a resin having proton conductivity is preferable. Examples of the proton conductive resin include polystyrene-sulfonic acid, polyvinylsulfonic acid and other olefinic resins introduced with sulfonic acid groups, sulfonic acid group-introduced polyimide resins, and sulfonic acids. Group-introduced phenol resin, sulfonic acid group-introduced polyether ketone resin, sulfonic acid group-introduced polybenzimidazole resin, polybenzimidazole resin salted with acid at imidazole moiety, styrene / ethylene / butylene -The sulfonic acid dope product of a styrene copolymer, perfluorosulfonic acid resin, etc. are mentioned.
In particular, perfluorosulfonic acid resins that are chemically stable by introducing fluorine atoms with high electronegativity, have a high degree of dissociation of sulfonic acid groups, and can realize high ionic conductivity have practicality. Highly preferred. Specific examples of such proton conductive resins include “Nafion” manufactured by DuPont, “Flemion” manufactured by Asahi Glass, “Aciplex” manufactured by Asahi Kasei, and “Gore Select” manufactured by Gore. Etc. Usually, a resin having proton conductivity is used as an alcohol aqueous solution containing about 5 to 30% by weight as a solid content. As the alcohol, for example, methanol, propanol, ethanol diethyl ether and the like are used.

<Solvent>
Although it does not specifically limit as a solvent, The thing which an oxide type non-platinum catalyst granule can maintain the shape in catalyst ink is preferable.
A solvent may be used individually by 1 type, or 2 or more types may be mixed and used for it. As the main solvent, water or a solvent having high affinity with water is preferable, and alcohol can be particularly preferably used. As such an alcohol, for example, a monohydric alcohol or a polyhydric alcohol having a boiling point of about 80 to 200 ° C. can be used, and an alcohol solvent having 4 or less carbon atoms is preferable. Specific examples include 1-propanol, 2-propanol, 1-butanol, 2-butanol, and t-butanol. Alcohol is used individually by 1 type or in mixture of 2 or more types. Among these monohydric alcohols, 2-propanol, 1-butanol and t-butanol are preferable. Specifically, the polyhydric alcohol is preferably, for example, propylene glycol, ethylene glycol or the like, particularly propylene glycol, from the viewpoint of compatibility with a resin having proton conductivity and drying efficiency when used as a catalyst ink. preferable.

<Dispersant>
As a dispersing agent, what was quoted when producing an oxide type non-platinum catalyst granulation body can be used suitably.

<Fuel cell>
Next, a fuel cell in which the oxide-based non-platinum catalyst granule according to the present invention is applied to an anode electrode and a cathode electrode will be described.

FIG. 1 shows a schematic configuration diagram of a fuel cell according to an embodiment of the present invention. The fuel cell includes a separator 1, a gas diffusion layer 2, an anode electrode catalyst (fuel electrode) 3, a cathode electrode catalyst (air electrode) 5, a gas diffusion layer 6, And a separator 7.
As the solid polymer electrolyte 4, a fluorine-based cation exchange resin membrane represented by a perfluorosulfonic acid resin membrane is used.

  Further, the oxide-based non-platinum catalyst granule produced by the production method of the present invention is brought into contact with both the solid polymer electrolyte 4 as the anode electrode catalyst 3 and the cathode electrode catalyst 5, so that the anode electrode catalyst 3 and A fuel cell is provided in which the cathode electrode catalyst 5 is provided with an oxide-based non-platinum catalyst granule.

  The above-mentioned oxide-based non-platinum catalyst granules are formed on both sides of the solid polymer electrolyte, and the anode electrode catalyst 3 and the cathode electrode catalyst 5 are hot on both main surfaces of the solid polymer electrolyte 4 on the electrode reaction layer side. By closely contacting with a press, it is integrated as a MEA (Membrane Electrode Assembly).

  The separators 1 and 7 supply and discharge reaction gases such as fuel gas (hydrogen) and oxidant gas (oxygen). When the reaction gas is uniformly supplied to the anode and cathode electrode catalysts 3 and 5 through the gas diffusion layers 2 and 6, the oxide-based non-platinum catalyst and the solid polymer electrolyte 4 provided on both electrodes are provided. At the boundary, a three-phase interface is formed of a gas phase (reactive gas), a liquid phase (solid polymer electrolyte membrane), and a solid phase (a catalyst possessed by both electrodes). A direct current is generated by causing an electrochemical reaction.

In the above electrochemical reaction,
Cathode side: O ₂ + 4H ⁺ + 4e ⁻ → 2H ₂ O
Anode side: H ₂ → 2H ⁺ + 2e ⁻
The H ⁺ ions generated on the anode side move in the solid polymer electrolyte 4 toward the cathode side, and e ⁻ (electrons) move to the cathode side through an external load.

On the other hand, on the cathode side, oxygen contained in the oxidant gas reacts with H ⁺ ions and e ⁻ that have moved from the anode side to generate water. As a result, the above-described fuel cell generates direct-current power from hydrogen and oxygen to generate water.

  The use of the oxide-based non-platinum catalyst granule produced by the production method in the present invention is not limited to the above-mentioned fuel cell electrode catalyst, but a metal-air cell electrode catalyst, an exhaust gas purification catalyst, etc. Can be used.

  EXAMPLES Hereinafter, although this invention is demonstrated in more detail based on an Example, this invention is not limited to an Example. In the examples, parts represent parts by weight, and% represents% by weight.

    Measurement of average particle diameter: Using a particle size distribution meter (Mastersizer 2000, manufactured by Malvern Instruments Inc.), a specific measurement method is to put a powder of an oxide-based non-platinum catalyst granule into a measurement cell, signal level Was measured when it showed the optimum value, and the obtained D50 value was taken as the average particle size.

<Synthesis of oxide-based non-platinum catalyst>

[Production Example 1]
A powder obtained by heat-treating Ta carbide (TaC) (TAI03PB manufactured by Kosei Chemical Co., Ltd.) in an electric furnace at 1000 ° C. for 10 hours in an O ₂ / Ar (3/7: volume ratio) mixed gas atmosphere. Was pulverized in a mortar to obtain an oxide-based non-platinum catalyst (1).

[Production Example 2]
Ta carbonitride (TaC _0.5 N _0.5 ) was heat-treated at 1000 ° C. for 10 hours in an O ₂ / Ar (3/7: volume ratio) mixed gas atmosphere in an electric furnace. By grinding, an oxide-based non-platinum catalyst (2) was obtained.

[Production Example 3]
Zr carbide (ZrC) (5OR08 manufactured by Allied Materials) was heat-treated at 1000 ° C. for 10 hours in an O ₂ / Ar (3/7: volume ratio) mixed gas atmosphere in an electric furnace. The oxide-based non-platinum catalyst (3) was obtained by pulverizing with a mortar.

[Production Example 4]
Zr carbonitride (ZrC _0.5 N _0.5 ) (5OV25 manufactured by Allied Materials) was heat-treated at 1000 ° C. for 10 hours in a mixed gas atmosphere in an electric furnace (3/7: volume ratio) and obtained powder Was pulverized in a mortar to obtain an oxide-based non-platinum catalyst (4).

[Production Example 5]
Oxyzirconium phthalocyanine (ZrOPc) (manufactured by Dainichi Seika Co., Ltd.) was heated in an electric furnace at 1000 ° C. under a mixed gas atmosphere of H ₂ / O ₂ / Ar (0.02 / 0.005 / 0.975: volume ratio). Heat treatment was performed for 10 hours, and the obtained powder was pulverized in a mortar to obtain an oxide-based non-platinum catalyst (5).
[Production Example 6]
Ta oxide (Ta ₂ O ₅ ) (TAO02PB manufactured by Kojundo Chemical Co., Ltd.) and metal-free phthalocyanine (manufactured by Tokyo Chemical Industry Co., Ltd.) are mixed in a mortar, and H ₂ / O ₂ / Ar (0. (02 / 0.005 / 0.975: volume ratio) Heat treatment was performed at 1000 ° C. for 10 hours in a mixed gas atmosphere, and the obtained powder was pulverized in a mortar to obtain an oxide-based non-platinum catalyst (6). .
[Example 1: Oxide-based non-platinum catalyst granule (1)]
Production Example after preparing 83 parts of ion-exchanged water and 10 parts of resin-type dispersant Jonkrill JDX-6500 (BASF Japan Ltd .: 30% solid content aqueous solution) having a carboxylic acid group in a glass bottle to prepare a uniform dispersion solution. After adding 4.7 parts of the oxide-based non-platinum catalyst (1) prepared in 1 and 2.3 parts of Ketjen Black (L-EC EC-600JD), and further adding zirconia beads as a medium, it was wetted with a paint conditioner. By mixing, an oxide-based non-platinum catalyst (1) dispersion (solid content: 10%) was obtained.
This oxide-based non-platinum catalyst (1) dispersion was spray-dried in a mini-spray dryer (“B-290” manufactured by Nippon Büch Co., Ltd.) in a nitrogen stream under an atmosphere of 125 ° C., and spherical with an average particle size of 12 μm. An oxide-based non-platinum catalyst granule (1) was obtained.

[Example 2: Oxide-based non-platinum catalyst granule (2)]
An oxide non-platinum catalyst (2) dispersion (solid content 10) was prepared in the same manner as in Example 1 except that the oxide non-platinum catalyst (2) was used instead of the oxide non-platinum catalyst (1). %).
This oxide-based non-platinum catalyst (2) dispersion was spray-dried in a mini-spray dryer ("B-290" manufactured by Nihon Büch Co., Ltd.) in a nitrogen stream in an atmosphere of 125 ° C, and spherical with an average particle size of 10 µm. An oxide-based non-platinum catalyst granule (2) was obtained.

[Example 3: Oxide-based non-platinum catalyst granule (3)]
Using the oxide-based non-platinum catalyst (3) prepared in Production Example 3, an oxide-based non-platinum catalyst (3) dispersion (solid content 10%) was obtained in the same manner as in Example 1.
The oxide-based non-platinum catalyst (3) dispersion was spray-dried in a mini-spray dryer (“B-290” manufactured by Nihon Buch Co., Ltd.) in a nitrogen stream under an atmosphere of 125 ° C., and spherical with an average particle size of 10 μm. An oxide-based non-platinum catalyst granule (3) was obtained.

[Example 4: Oxide-based non-platinum catalyst granule (4)]
Using the oxide-based non-platinum catalyst (4) prepared in Production Example 4, an oxide-based non-platinum catalyst (4) dispersion (solid content 10%) was obtained in the same manner as in Example 1.
This oxide-based non-platinum catalyst (4) dispersion was spray-dried in a mini-spray dryer (“B-290” manufactured by Nihon Büch) in a nitrogen stream under an atmosphere of 125 ° C., and spherical with an average particle size of 8 μm. An oxide-based non-platinum catalyst granule (4) was obtained.

[Example 5: Oxide-based non-platinum catalyst granule (5)]
Using the oxide-based non-platinum catalyst (5) prepared in Production Example 5, an oxide-based non-platinum catalyst (5) dispersion (solid content 10%) was obtained in the same manner as in Example 1.
This oxide-based non-platinum catalyst (5) dispersion was spray-dried in a mini-spray dryer (“B-290” manufactured by Nippon Büch Co., Ltd.) in a nitrogen stream under an atmosphere of 125 ° C., and spherical with an average particle size of 10 μm. An oxide-based non-platinum catalyst granule (5) was obtained.

[Example 6: Oxide-based non-platinum catalyst granule (6)]
Using the oxide-based non-platinum catalyst (6) produced in Production Example 5, an oxide-based non-platinum catalyst (6) dispersion (solid content 10%) was obtained in the same manner as in Example 1.
This oxide-based non-platinum catalyst (6) dispersion was spray-dried in a mini-spray dryer (“B-290” manufactured by Nihon Buch Co., Ltd.) in a nitrogen stream under an atmosphere of 125 ° C., and spherical with an average particle size of 10 μm. An oxide-based non-platinum catalyst granule (6) was obtained.

[Example 7: Oxide-based non-platinum catalyst granule (7)]
In a glass bottle, 83 parts of ion-exchanged water and 30 parts of pigment derivative iron phthalocyanine derivative FePc- (SO ₃ NH ₄ ) 4 (manufactured by Nippon Steel Mining Co., Ltd .: 10% solid content aqueous solution) are weighed to prepare a uniform dispersion solution, and then manufactured. After adding 4.7 parts of the oxide-based non-platinum catalyst (1) prepared in Example 1 and 2.3 parts of Ketjen Black (EC-600JD manufactured by Lion Corporation), and further adding zirconia beads as a medium, the paint conditioner was used. Dispersion was performed to obtain an oxide-based non-platinum catalyst (1) dispersion (solid content 10%).
This oxide-based non-platinum catalyst (1) dispersion was spray-dried in a mini-spray dryer (“B-290” manufactured by Nihon Büch Co., Ltd.) in a nitrogen stream under an atmosphere of 125 ° C., and spherical with an average particle size of 10 μm. An oxide-based non-platinum catalyst granule (7) was obtained.

[Example 8: Oxide-based non-platinum catalyst granule (8)]
Production Example after preparing 83 parts of ion-exchanged water and 10 parts of resin-type dispersant Jonkrill JDX-6500 (BASF Japan Ltd .: 30% solid content aqueous solution) having a carboxylic acid group in a glass bottle to prepare a uniform dispersion solution. After adding 4.7 parts of the oxide-based non-platinum catalyst (1) prepared in 1 and 2.3 parts of carbon nanotubes (VGCF-H manufactured by Showa Denko KK), add zirconia beads as a medium, and then disperse with a paint conditioner. As a result, an oxide-based non-platinum catalyst (1) dispersion (solid content: 10%) was obtained.
This oxide-based non-platinum catalyst (1) dispersion was spray-dried in a mini-spray dryer (“B-290” manufactured by Nippon Büch Co., Ltd.) in a nitrogen stream under an atmosphere of 125 ° C., and spherical with an average particle size of 12 μm. An oxide-based non-platinum catalyst granule (8) was obtained.

[Example 9: Oxide-based non-platinum catalyst granule (9)]
In a glass bottle, 83 parts of propylene glycol and 3 parts of a resin-type dispersant polyvinylpyrrolidone PVP K-30 (manufactured by ASP Japan Co., Ltd.) were weighed to prepare a uniform dispersion, and then the oxide-based non-platinum produced in Production Example 1 After adding 4.7 parts of catalyst (1) and 2.3 parts of Ketjen Black (EC-600JD manufactured by Lion Corporation), and further adding zirconia beads as a medium, the mixture was dispersed with a paint conditioner, and an oxide-based non-platinum catalyst ( 1) A dispersion (solid content 10%) was obtained.
This oxide-based non-platinum catalyst (1) dispersion was spray-dried in a mini-spray dryer (“B-290” manufactured by Nippon Büch Co., Ltd.) in a nitrogen stream under an atmosphere of 125 ° C., and spherical with an average particle size of 12 μm. An oxide-based non-platinum catalyst granule (9) was obtained.

[Comparative Example 1: Oxide-based non-platinum catalyst (1)]
The oxide-based non-platinum catalyst (1) produced in Production Example 1 was used as it was as a comparative example without granulation.
[Comparative Examples 2 to 6: Oxide-based non-platinum catalysts (2) to (6)]
Similar to Comparative Example 1, the oxide-based non-platinum catalysts (2) to (6) prepared in Production Examples 2 to 6 were used as Comparative Examples 2 to 6 without granulation.

[Comparative Example 7: Dispersion containing no dispersant]
Add 6.7 parts of the oxide-based non-platinum catalyst (1) prepared in Production Example 1 and 3.3 parts of Ketjen Black (L-EC EC-600JD) to 90 parts of ion-exchanged water in a glass bottle. After adding the zirconia beads, they were dispersed with a paint conditioner. The obtained dispersion had high viscosity and no fluidity, and it was difficult to produce a uniform dispersion without adding a dispersant.

<Oxygen reduction activity evaluation of oxide-based non-platinum catalysts>

  The oxide-based non-platinum catalyst granules (1) to (9) obtained in Examples 1 to 9 and the oxide-based non-platinum catalysts (1) to (6) obtained in Comparative Examples 1 to 6 were added on the glassy carbon. The oxygen reduction activity was evaluated using the electrode dispersed in. The evaluation method is as follows.

(1) Inking method Weighing 0.01 parts of oxide-based non-platinum catalyst or oxide-based non-platinum catalyst granulated body, and water, propanol and butanol mixed solution in which Nafion (manufactured by DuPont) is dispersed as a binder After adding to 3.56 parts (solid content 0.19%), it was subjected to dispersion treatment with ultrasonic waves (42 kHz) for 15 minutes to obtain an oxide-based non-platinum catalyst ink.

(2) Working electrode preparation method After polishing the surface of the rotating electrode (glassy carbon electrode radius 0.2 cm) to a mirror surface, 3.5 μl of the above oxide-based non-platinum catalyst ink was dropped onto the electrode surface and spin coated at 1500 rpm. Then, a working electrode was produced by natural drying.

(3) LSV (Linear Sweep Voltammetry) Measurement An electrolytic solution (0.5 M sulfuric acid aqueous solution) is placed in an electrolytic cell equipped with the working electrode prepared above, a counter electrode (platinum), and a reference electrode (Ag / AgCl), and oxygen A reduction activity test was performed.

  The oxygen reduction starting potential, which is an index of the degree of oxygen reduction activity, was measured by performing bubbling with oxygen in the electrolytic solution and then rotating the working electrode at 2000 rpm in an oxygen atmosphere to perform LSV measurement. Incidentally, after bubbling with nitrogen in the electrolytic solution, a value obtained by performing LSV measurement in a nitrogen atmosphere was used as the background.

The oxygen reduction starting potential was calculated by reading the potential when the current density reached −50 μA / cm ² and converting it to a potential based on the reversible hydrogen electrode (RHE). The oxygen reduction start potential indicates that the higher the potential, the higher the oxygen reduction activity. The evaluation results are shown in Table 1.

  As a standard sample, the degree of oxygen reduction activity of platinum-supported carbon (platinum support ratio of 50% by weight) was measured by the above-described evaluation method. As a result, the oxidation-reduction starting potential was 0.94 V (vs RHE).

  As can be seen from Table 1, all of the oxide-based non-platinum catalyst granules (1) to (9) synthesized by the production method of the production example had higher oxygen reduction activity than the comparative example. .

    Next, oxide-based non-platinum catalyst granules (1) to (9) obtained in Examples 1 to 9 and oxide-based non-platinum catalysts (1) to (6) obtained in Comparative Examples 1 to 6 Was used to prepare a catalyst ink and a catalyst layer for a fuel cell, and the battery performance was evaluated.

<Preparation of catalyst ink>
17.14 parts of oxide-based non-platinum catalyst granules (1) to (9) obtained in Examples 1 to 9 (12 parts of oxide-based non-platinum catalyst + 5.14 parts of resin having a hydrophilic functional group) Was added to a mixed solution of 68.57 parts of 1-butanol and 14.29 parts of Nafion solution (manufactured by DuPont: solid 20% water-alcohol mixed solution), and then disperse (manufactured by Primics, Catalyst inks (1) to (9) (solid content concentration 20%, catalyst ink 100% when the catalyst ink is 100% by stirring and mixing with TK homodispers) A total ratio) was prepared.
On the other hand, the oxide-based non-platinum catalysts (1) to (6) and 12 parts obtained in Comparative Examples 1 to 6 were weighed, and 48 parts of 1-butanol and a Nafion solution (manufactured by DuPont: solid content 20%) Water-alcohol mixed solution) After being added to 40 parts by weight of the mixed solution, catalyst inks (10) to (15) (solid content concentration of 20) were obtained by stirring and mixing with a disper (manufactured by Primics, TK homodisper). The ratio of the oxide-based non-platinum catalyst and the binder when the weight is 100% by weight and the catalyst ink is 100% by weight) was prepared.

<Evaluation of catalyst ink>
The dispersibility of the catalyst ink was evaluated by the following evaluation method.

(Dispersibility evaluation)
The dispersibility is determined by a grind gauge (according to JIS K5600-2-5), and the particle size (coarse dispersed particle size) of the catalyst ink is determined. If there is no aggregate of 50 μm or more, the dispersibility is evaluated as good. did. While the particle sizes of the catalyst inks of the oxide-based non-platinum catalyst granules (1) to (9) obtained in Examples 1 to 9 were all 20 to 30 μm and the dispersibility was good, In the catalyst inks of the oxide-based non-platinum catalysts (1) to (6) of Comparative Examples 1 to 6, aggregated particles of 100 μm or more were confirmed, and it was confirmed that the dispersibility was inferior. The evaluation results are shown in Table 1.

<Preparation of fuel cell catalyst layer>
The catalyst inks (1) to (9) of Examples 1 to 9 were applied onto a Teflon (registered trademark) film with a doctor blade so that the basis weight of the oxide-based non-platinum catalyst after drying was 2 mg / cm ^2. It was applied and dried at 95 ° C. for 15 minutes in an air atmosphere to produce a uniform cathode fuel cell catalyst layer with no unevenness.
However, in the catalyst inks (10) to (15) obtained in Comparative Examples 1 to 6, the catalyst layer had unevenness.

<Coating property evaluation>
The fuel cell catalyst layer was evaluated by the following coating property evaluation. The fuel cell catalyst layer formed on the Teflon (registered trademark) film was observed with a video microscope VHX-900 (manufactured by Keyence Corporation) at a magnification of 500 times, and coating unevenness (unevenness: evaluated by the density of the catalyst layer) In addition, pinholes (evaluated by the presence or absence of defects on which no catalyst layer was applied) were determined according to the following criteria. The evaluation results are shown in Table 1.
(village)
○: The density of the catalyst layer is not confirmed (good).
(Triangle | delta): Although there are 2-3 shades of a catalyst layer, it is a very small area | region (it is satisfactory practically).
X: A large number of shades of the catalyst layer is confirmed, or one or more of the stripes having a length of 5 mm or more (defective).
(Pinhole)
○: No pinholes are confirmed (good).
Δ: There are 2 to 3 pinholes but they are very small (defect).
X: Many pinholes are confirmed, or one or more pinholes having a diameter of 1 mm or more (very poor).

<Production of anode fuel cell catalyst layer>
Here, a method for producing a catalyst layer for an anode fuel cell used for producing an electrode membrane assembly for a fuel cell will be described below.
Instead of the oxide-based non-platinum catalyst, 4 parts of platinum catalyst-supporting carbon (Tanaka Kikinzoku Co., Ltd., platinum amount 46%), 1-propanol 56 parts as solvent, and 20 parts of water into disperse (Primics, TK homodispers) The catalyst paste composition (solid content concentration 4%) was prepared by stirring and mixing. Next, 20 parts of a Nafion solution (manufactured by DuPont: 20% solids water-alcohol mixed solution) is added, and the mixture is stirred and mixed with a disper (manufactured by Primics, TK homodisper) to obtain catalyst ink (solid A partial concentration of 8%). The obtained catalyst ink was applied onto a Teflon (registered trademark) film so that the weight per unit area of the platinum catalyst-supported carbon was 0.46 mg / cm ^2, and dried for 15 minutes at 70 ° C. in an air atmosphere. A catalyst layer for an anode fuel cell was prepared.

<Production of fuel cell electrode membrane assembly>
Cathode fuel cell catalyst layers and anode fuel cell catalyst layers prepared in Examples 1 to 9 and Comparative Examples 1 to 6 were respectively made of solid polymer electrolyte membranes (Nafion 212, manufactured by DuPont, film thickness 50 μm). ) And was held under conditions of 150 ° C. and 5 MPa, and then the Teflon (registered trademark) film was peeled off. Next, the electrode base material (gas diffusion layer GDL, carbon paper made of carbon fiber, TGP-H-090, manufactured by Toray Industries, Inc.) is further adhered from both sides, and the electrode membrane assembly for fuel cell of the present invention (GDL / Catalyst layer / solid polymer electrolyte membrane / catalyst layer / GDL).

<Fabrication of fuel cell (single cell)>
The fuel cell electrode membrane assemblies obtained in Examples 1 to 9 and Comparative Examples 1 to 6 were used as 2 cm square samples, sandwiched between two gaskets from both sides and then two separators that were graphite plates, and from both sides. Two current collector plates were attached to produce a fuel cell (single cell). The measurement was carried out by Auto PEM series “PEFC evaluation system” manufactured by Toyo Technica. As fuel cell operating conditions, a power generation test was carried out under conditions of a temperature of 80 ° C. and a relative humidity of 100% by flowing hydrogen at 300 ml / min on the anode side and oxygen at 300 ml / min on the cathode side.

<Evaluation of fuel cell (single cell)>
The power generation characteristics of the batteries were evaluated by measuring the current-voltage characteristics of the single cells prepared in Examples 1 to 9 and Comparative Examples 1 to 6.
As a result, in the single cells produced in Examples 1 to 9, the open circuit voltage was 0.94 V to 0.98 V, and the short circuit current density was 950 to 1200 mA / cm ² . On the other hand, the single cells produced in Comparative Examples 1 to 6 had an open circuit voltage of 0.94 to 0.98 V and a short circuit current density of 600 to 800 mA / cm ² , which were lower than the examples.
In the power generation test results, there is no significant difference in the open circuit voltage. This is considered to be because the influence of conductivity is small when no current is generated (or in a very small region), and the catalytic activity of the oxide-based non-platinum catalyst itself is the dominant factor. On the other hand, there is a large difference in the short-circuit current density, which is thought to be due to the fact that conductivity is the dominant factor in the high current region, and the conductive carbon material is uniformly distributed with the oxide-based non-platinum catalyst. It can be seen that it is important to ensure contact and secure a conductive path.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

FIG. 1 is a diagram showing the configuration of a fuel cell in which the oxide-based non-platinum catalyst of the present invention is applied to an electrode catalyst.

1 Separator 2 Gas diffusion layer 3 Anode electrode catalyst (fuel electrode)
4 Solid polymer electrolyte 5 Cathode electrode catalyst (Air electrode)
6 Gas diffusion layer 7 Separator

Claims (6)

  An oxide-based non-platinum catalyst granule containing an oxide-based non-platinum catalyst, a conductive carbon material, and a dispersant, wherein the oxide-based non-platinum catalyst granule has a spherical or elliptical shape. An oxide-based non-platinum catalyst granule which is in the form of a body and has an average particle diameter of 0.5 to 100 μm.   2. The oxide-based non-platinum catalyst granule according to claim 1, wherein the oxide-based non-platinum catalyst contains at least one element selected from the group consisting of Ti, Zr, Nb, V, Mo, W and Ta. .   An oxide comprising: a step 1 for wet-mixing an oxide-based non-platinum catalyst, a conductive carbon material, and a dispersant; and a step 2 for spray-drying and granulating the paste obtained by the mixing. Of producing a non-platinum-based catalyst granule.   An oxide-based non-platinum catalyst granule produced by the production method according to claim 3.   Catalyst ink containing the oxide-based non-platinum catalyst granule according to any one of claims 1, 2, and 4, a binder, and a solvent. An electrode membrane assembly in which the catalyst layer containing the oxide-based non-platinum catalyst granule according to any one of claims 1, 2, and 4 is bonded to one or both surfaces of the solid polymer electrolyte membrane. A fuel cell.

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