JP7205209B2 - Catalyst ink material for biofuel cell anode, catalyst ink composition for biofuel cell anode, biofuel cell anode, biofuel cell device - Google Patents

Description

The present invention relates to a biofuel cell anode catalyst ink material, a biofuel cell anode catalyst ink composition, a biofuel cell anode, and a biofuel cell device.

With the spread of portable electronic devices such as mobile phones and laptop computers, and the advent of the IoT society in which all kinds of things are connected to the Internet and exchange information, the forms of power supply usage are becoming more diverse. Currently, primary batteries and secondary batteries are cited as main portable power sources, and are widely used in electronic devices. In addition, for small devices such as sensors, which are expected to be used more in the future, the use of fuel cells, solar power generation, etc. is being considered in addition to conventional batteries.

Biofuel cells, which have been under development in recent years, are power-generating devices that utilize electrical energy generated by enzymatic reactions or the like using organic substances such as sugars, alcohols, and organic acids as fuel. In most cases, oxidoreductase is used for the cathode and anode, and it is an energy system that generates electricity using a wide variety of organic substances and oxygen in the air as fuel. The high safety of is mentioned as an advantage (patent document 1). However, since it is necessary to further improve the output characteristics, a biofuel cell (Patent Document 2) using an electrode in which an enzyme and a mediator are immobilized on carbon paper, or carbon and / or an inorganic compound, fuel, enzyme, and a biofuel cell using an electrode composed of an enzyme-immobilized compound such as a pyrene compound has also been reported (Patent Document 3).
On the other hand, biofuel cells that generate electricity by direct oxidation of organic matter as fuel using electrodes that do not use expensive precious metals or enzymes are also being studied. For example, a biofuel cell using ascorbic acid or the like as a fuel and carbon cloth impregnated with carbon black without using a noble metal as an anode catalyst has been reported (Non-Patent Document 1, Patent Document 4). Furthermore, an example of an investigation of improving power generation characteristics by using a carbon felt coated with carbon black and polyvinylpyridine resin as an anode and using a solution of ascorbic acid in combination with imidazole or the like as a fuel has also been reported (Patent Document 5). However, the output characteristics are still insufficient because no catalyst is used.

JP-A-2005-310613 JP-A-2006-49215 WO2012105462 WO2004019436 WO2014098171

Electrochem. Solid-State Lett. (2003), volume 6, issue 12, 257-259

Since the above-mentioned fuel cell uses an organic material that is safe for living organisms as fuel, it is expected to be used as a power source for wearable devices, implant devices, and the like for living organisms. However, at present, expensive noble metal catalysts are used for cathodes and anodes, and material costs are a problem. When enzymes are used for cathodes and anodes, durability is not sufficient in addition to material costs. Also, if no noble metal catalysts or enzymes are used, the output needs to be further improved.
An object of the present invention is to provide a catalyst ink material for a biofuel cell anode, a catalyst ink composition for a biofuel cell anode, a biofuel cell anode, a biofuel, which is excellent in output and durability and is low in cost and uses a reducing organic substance as a fuel. It is to provide a battery device.

The present inventor has arrived at the present invention as a result of repeated studies in order to solve the above problems.
That is, the present invention provides a catalyst ink material for a fuel cell anode that uses a reducing organic substance as a fuel and is made of a carbon material having a carbon hexagonal mesh plane as a basic skeleton,
The carbon material contains a hetero element and/or a base metal element as a constituent element, and is doped so that at least part of the carbon element in the carbon skeleton is substituted with the hetero element. A reducing organic substance. and catalyst ink materials for biofuel cell anodes fueled by .

The present invention also relates to a biofuel cell anode catalyst ink composition using a reducing organic substance as fuel, comprising the above biofuel cell anode catalyst ink material and a binder resin.

The present invention also relates to a biofuel cell anode that uses a reducing organic substance as a fuel and has a coating film formed from the above catalyst ink composition for a biofuel cell anode.

The present invention also relates to a biofuel cell device comprising the biofuel cell anode, the biofuel cell cathode, and a fuel containing a reducing organic substance.

Further, in the present invention, the reducing organic substance is one or more selected from the group consisting of ascorbic acid, ascorbic acid derivatives, erythorbic acid, erythorbic acid derivatives, nicotinamide adenine dinucleotide, and nicotinamide adenine dinucleotide derivatives. The above biofuel cell device characterized by

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a biofuel cell that uses reducing organic matter as a fuel and has excellent output and durability. In addition, since the use of expensive metal materials and enzymes can be reduced, a low-cost device can be produced.

The present invention will be described in detail below.

<Catalyst ink material for biofuel cell anode>
First, a catalyst ink material for a biofuel cell anode will be described. The catalyst ink material for a biofuel cell anode of the present invention is composed of a carbon material having a carbon hexagonal mesh plane as a basic skeleton, and has physical and chemical interactions (bonds) between its constituent units, It is a material containing elements (heterogeneous elements such as N, B, and P) and/or base metal elements. The base metal element referred to here is a metal element excluding noble metal elements (ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, gold) among transition metal elements. Examples of base metal elements include cobalt, iron, nickel, It preferably contains one or more selected from the group consisting of manganese, copper, titanium, vanadium, chromium, zinc, and tin. Containing a hetero element or a base metal element activates the anode reaction.

The catalyst ink material for a biofuel cell anode in the present invention preferably has a large specific surface area and high electronic conductivity. Since the reaction that occurs at the anode occurs on the surface of the material, the larger the specific surface area, the greater the number of reaction fields with the reducing organic fuel and electrons, which leads to an improvement in reaction activity, which is preferable. In addition, the higher the electron conductivity, the more electrons necessary for the reaction in the electrode can be supplied to the reaction field, which is preferable because it tends to lead to an increase in current.

In the biofuel cell anode catalyst ink material of the present invention, the ratio of the molar ratio of heteroatoms to the molar ratio of carbon atoms is preferably in the range of 1 to 40%. The ratio of the molar ratio of base metal atoms to the molar ratio of carbon atoms is preferably in the range of 0.01 to 20%.
For example, when the heteroatom is nitrogen, the molar ratio of carbon atoms, nitrogen atoms and base metal atoms to all the elements constituting the material are represented by R _C , R _N and R _M , respectively. In this case, the ratio of the molar ratio R _N of nitrogen atoms to the molar ratio R _C of carbon atoms is 1 to 40%, and the ratio R _M of the base metal atoms to the molar ratio R _C of carbon atoms is 0.01 to 20%. is preferably in the range of

The catalyst ink material for a biofuel cell anode in the present invention preferably has a BET specific surface area (BET _N2 ) with nitrogen as an adsorbing species of 1 to 1500 m ² /g, more preferably 10 to 1000 m ² /g. be. When the BET specific surface area is within the above range, it is preferable because the reaction field in which the reaction occurs can be increased.

The specific surface area in the present invention means the surface area per unit mass of sample, and can be determined by a gas (N ₂ ) adsorption method. The analysis method uses the BET method, and from the intercept and slope of the straight line obtained by plotting the relative pressure (P (adsorption equilibrium pressure) / P0 (saturated vapor pressure) = 0.05 to 0.3) and the amount of gas adsorption, the single By obtaining the molecular adsorption amount, the BET specific surface area can be calculated.

The catalyst ink material for a biofuel cell anode in the present invention has a peak at a diffraction angle (2θ) of 24.0 to 27.0° in an X-ray diffraction (XRD) diagram obtained using CuKα rays as an X-ray source. The existence of the carbon hexagonal mesh plane can be confirmed by having it. Also, the half width of the peak is preferably 8° or less.

In the X-ray diffraction diagram of the biofuel cell anode catalyst ink material obtained using CuKα rays as the X-ray source, the (002) plane diffraction peak of carbon appears at around 24.0 to 27.0°. The position of the (002) diffraction peak of carbon varies depending on the interplanar distance of the hexagonal carbon planes, and the higher the angle of the peak position, the closer the distance between the hexagonal carbon planes. is shown. The sharper the peak (the smaller the half-value width), the larger the crystallite size and the more advanced the crystal structure.

When the half width of the peak is 8° or less, the catalyst ink material for a biofuel cell anode has high crystallinity and high electronic conductivity. As a result, the electrons required for the reaction in the electrode can be supplied to the reaction field, which leads to an increase in current, which is preferable.

Further, it is more preferable that the half width of the peak is 1° or less.

<Method for producing catalyst ink material for biofuel cell anode>
In a method for producing a catalyst ink material for a biofuel cell anode, by selecting an optimum mixing device, dispersing device, or drying device for a compound containing a carbonaceous raw material and a hetero element and/or a base metal element, A catalyst ink material for a biofuel cell anode having excellent catalytic activity can be obtained.

The catalyst ink material for a biofuel cell anode in the present invention is a mixture of a carbon-based raw material and a compound containing a hetero element, a mixture of a carbon-based raw material and a compound containing a base metal element, or a mixture of a carbon-based raw material and a hetero element. It is not a mixture of compounds containing metals or base metal elements.

Examples of the method for producing the catalyst ink material include a method of mixing and carbonizing a carbonaceous raw material, a compound containing a hetero element and a compound containing a base metal element,
A method of mixing and carbonizing a carbonaceous raw material and a compound containing a hetero element,
A method of mixing and carbonizing a carbonaceous raw material containing a hetero element and a compound containing a base metal element,
A method of carbonizing a compound containing heteroelements and base metal elements such as macrocyclic compounds such as phthalocyanines and porphyrins,
Examples include, but are not limited to, a method of mixing a carbonaceous raw material with a compound containing a hetero element and a base metal element and carbonizing the mixture.

By carbonization, a carbon material having a carbon hexagonal mesh plane as a basic skeleton is obtained, and the carbon material is doped so that at least part of the carbon elements in the carbon skeleton on the surface of the carbon material is replaced with a hetero element. Alternatively, the carbon-based raw material may be doped with a gas containing a hetero element instead of a compound containing a hetero element.
Examples of such a production method include a method of doping a hetero element in a material obtained by mixing and carbonizing a carbonaceous raw material and a compound containing a base metal element by a vapor phase method;
A conventionally known method such as a method of doping a carbonaceous raw material with a hetero element by a vapor phase method can be used, but the method is not limited thereto.
By the reaction in the gas phase method, the carbon-based raw material is doped so that at least part of the carbon elements in the carbon skeleton on the surface of the carbon-based raw material is replaced with a hetero element.
Preferred production methods include a method of mixing a carbon-based raw material containing at least a hetero element and a compound containing a base metal element and heat-treating the mixture, or a method of mixing at least a carbon-based raw material with a compound containing a hetero element and a base metal element, A method of heat treatment is mentioned. Moreover, the method includes the steps of washing the carbon material obtained by the heat treatment with an acid and drying it. Furthermore, there is a method including a step of heat-treating the carbon material obtained by the acid washing.
In addition, the base metal element does not become an element forming the hexagonal carbon network plane, but exists in the vicinity of the hexagonal carbon network plane.

<Carbon-based raw material>
Inorganic carbon-based raw materials are preferable as the carbon-based raw materials that are constituent components of the catalyst ink material for biofuel cell anodes in the present invention. Examples thereof include carbon black (furnace black, acetylene black, ketjen black, medium thermal carbon black), activated carbon, graphite, carbon nanotubes, carbon nanofibers, carbon nanohorns, graphene nanoplatelets, nanoporous carbon, and carbon fibers. Carbon-based raw materials vary in crystallinity, particle size, shape, BET specific surface area, pore volume, pore size, bulk density, DBP oil absorption, surface acid-basicity, surface hydrophilicity, conductivity, etc., depending on the type and manufacturer. Since they have different physical properties and costs, the most suitable material can be selected according to the intended use and required performance.

Commercially available inorganic carbon-based raw materials include, for example,
Ketjenblack manufactured by Lion Specialty Chemicals such as Ketjenblack EC-300J, EC-600JD, Lionite EC-200L;
Furnace blacks manufactured by Tokai Carbon Co., Ltd. such as Toka Black #4300, #4400, #4500, and #5500;
Degussa furnace black such as Printex L;
Columbian furnace blacks such as Raven 7000, 5750, 5250, 5000 ULTRA III, 5000 ULTRA, Conductex SC ULTRA, 975 ULTRA, PUER BLACK 100, 115, and 205;
Mitsubishi Chemical Furnace Blacks such as #2350, #2400B, #2600B, #3050B, #3030B, #3230B, #3350B, #3400B, and #5400B;
Cabot furnace blacks such as MONARCH 1400, 1300, 900, Vulcan XC-72R, and BlackPearls 2000;
TIMCAL furnace blacks such as Ensaco 250G, Ensaco 260G, Ensaco 350G, and SuperP-Li;
Acetylene black manufactured by Denka such as Denka Black, Denka Black HS-100, and FX-35;
Showa Denko carbon nanotubes such as VGCF, VGCF-H, and VGCF-X;
Carbon nanotubes manufactured by Meijo Nano Carbon;
xGnP-C-300, xGnP-C-500, xGnP-C-750, xGnP-M-5, xGnP-M-15, xGnP-M-25, xGnP-H-5, xGnP-H-15, xGnP- XGSciences graphene nanoplatelets such as H-25;
Nanoporous carbon manufactured by Easy-N;
Carbon fibers manufactured by Gun Ei Chemical Industry Co., Ltd., such as Kynor diisosia and Kynor activated carbon fibers;
Knobel MH grade, Knobel P (2) 010 grade, Knobel P (3) 010 grade, Knobel P (4) 050 grade, Knobel MJ (4) 030 grade, Knobel MJ (4) 010 grade, etc. carbon, etc., but are not limited to these.

As the carbon-based raw material, which is a component of the catalyst ink material for a biofuel cell anode in the present invention, not only an inorganic carbon-based raw material, but also an organic material that becomes carbon particles having a basic skeleton of a hexagonal carbon network surface after heat treatment is used. can do. The organic material that becomes carbon particles after heat treatment may contain other elements besides carbon. In some cases, it is preferable to use an organic material containing a hetero element such as nitrogen or boron in advance in order to allow the heat-treated carbon particles to contain the hetero element. Specific organic materials include phenol-based resins, polyimide-based resins, polyamide-based resins, polyamide-imide-based resins, polyacrylonitrile-based resins, polyaniline-based resins, phenol-formaldehyde-based resins, polyimidazole-based resins, polypyrrole-based resins, poly Benzimidazole-based resins, melamine-based resins, pitch, lignite, polycarbodiimide, biomass, proteins, humic acid, and derivatives thereof can be used. Among them, polyimide-based resins, polyamide-based resins, polyamide-imide-based resins, polyacrylonitrile-based resins, polyaniline-based resins, etc., which are organic materials containing hetero elements such as nitrogen and boron, are preferable as carbon-based raw materials containing nitrogen elements. .

<Compound containing hetero element and/or base metal element>
The raw material used for introducing the hetero element and the base metal element into the catalyst ink material for the biofuel cell anode in the present invention is not particularly limited as long as it is a compound containing the hetero element and/or the base metal element.
Examples include organic compounds such as dyes and polymers, and inorganic compounds such as elemental metals, metal oxides and metal salts. Moreover, one type may be used alone, or two or more types may be used in combination.
Base metal elements are transition metal elements excluding noble metal elements (ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, and gold). Base metal elements include cobalt, iron, nickel, manganese, and copper. , titanium, vanadium, chromium, zinc and tin.
A nitrogen-containing aromatic compound, which is preferably a complex or a salt, and which can contain a base metal element in the molecule, can efficiently combine a nitrogen element and a base metal in a catalyst ink material for a biofuel cell anode. It is preferable because it is easy to introduce the element. Specific examples include macrocyclic compounds such as phthalocyanine-based compounds, naphthalocyanine-based compounds, porphyrin-based compounds, and tetraazaannulene-based compounds. The aromatic compound may be one into which an electron-withdrawing functional group or an electron-donating functional group has been introduced. In particular, phthalocyanine-based compounds are particularly preferable as raw materials because compounds containing various base metal elements are available and are inexpensive. Among them, cobalt phthalocyanine-based compounds, nickel phthalocyanine-based compounds, and iron phthalocyanine-based compounds are more preferable because they can provide inexpensive and highly active catalyst ink materials for biofuel cell anodes.

A combination of a plurality of raw materials can be considered as the origin of the elements introduced into the catalyst ink material for the biofuel cell anode.
The carbon element is an inorganic carbon material, an organic material that becomes carbon particles after heat treatment, a compound containing a hetero element and / or a base metal element, etc.
The hetero element includes an organic material that becomes carbon particles after heat treatment; a compound that includes a hetero element and/or a base metal element; a reactive gas that includes a hetero element such as ammonia;
A base metal element is a hetero element and/or a compound containing a base metal element, including a base metal element.

Examples of raw material combinations include:
The carbon element is an inorganic carbon-based raw material, the hetero-element is a carbon-based raw material for a biofuel cell anode derived from the hetero dope of the gas phase method,
The carbon element is an organic carbon-based raw material, and the hetero-element is a carbon-based raw material for a biofuel cell anode derived from N doping in the vapor phase method,
A carbon-based raw material for a biofuel cell anode derived from an organic material that becomes carbon particles after heat treatment of a carbon element and a hetero element,
A carbon-based raw material for a biofuel cell anode derived from a compound containing a hetero element and/or a base metal element, wherein the carbon element is an inorganic carbon-based raw material, and the hetero element and the base metal element are the hetero element and the base metal element,
A carbon-based raw material for a biofuel cell anode derived from a compound containing a hetero element and/or a base metal element, including an organic material that becomes carbon particles after heat treatment of the carbon element, a hetero element and a base metal element,
The carbon element is an organic carbon-based raw material, the hetero element is a compound containing a hetero element and / or a base metal element that does not contain a base metal element, the base metal element is a hetero element that does not contain a hetero element and / or contains a base metal element Carbon-based feedstocks for biofuel cell anodes derived from compounds,
A carbon-based raw material for a biofuel cell anode derived from an organic material that becomes carbon particles after heat treatment of a carbon element and a hetero element, and a biofuel cell derived from a compound containing a hetero element and/or a base metal element containing a base metal element as a base metal element carbon-based raw materials for anodes,
A carbon-based raw material for a biofuel cell anode derived from a compound containing a carbon element, a hetero element and a base metal element, including a carbon element, a hetero element and a base metal element, and/or a hetero element and/or a base metal element.

As a method for producing a precursor that is a mixture of raw materials, a carbon material and one or more types of hetero element and/or base metal element are included so that the precursor contains a carbon element, a hetero element, and a base metal element. When the compound is mixed, it is sufficient that the raw materials are uniformly mixed and compounded, and examples of the mixing method include dry mixing and wet mixing. As a mixing device, a dry mixing device or a wet mixing device as described below can be used.

As a dry mixing device, for example,
2-roll or 3-roll roll mills, high-speed agitators such as Henschel mixers and super mixers, fluid energy pulverizers such as micronizers and jet mills, attritors, Hosokawa Micron's particle compounding equipment "Nanocure" and "Nobilta" , "Mechanofusion", powder surface modification apparatus "Hybridization System" manufactured by Nara Machinery Co., Ltd., "Mechanomicros", and "Mirraro".

When using a dry mixing apparatus, other raw materials may be directly added in powder form to the base raw material powder. It is preferable to dissolve or disperse the powder in a solvent and add it while loosening the agglomerated particles of the base material powder. Furthermore, heating may be preferred in order to increase processing efficiency.

Among compounds containing heteroelements and/or base metal elements, there are materials that are solid at room temperature but have a low melting point, softening point, or glass transition temperature of less than 100°C. When these materials are used, it may be possible to achieve more uniform mixing by melting and mixing under heating than by mixing at room temperature.

In the case of wet mixing, a step of drying the dispersion produced using a wet mixing apparatus is required. In this case, the drying apparatus used includes a tray dryer, a rotary dryer, a flash dryer, a spray dryer, a stirring dryer, a freeze dryer, and the like.

As a wet mixing device, for example,
Mixers such as disper, homomixer, or planetary mixer;
Homogenizers such as "Clairmix" manufactured by M Technic Co., Ltd. or "Filmix" manufactured by PRIMIX;
Paint conditioner (manufactured by Red Devil), ball mill, sand mill ("Dyno Mill" manufactured by Shinmaru Enterprises, etc.), attritor, pearl mill ("DCP Mill" manufactured by Eirich, etc.), or media-type dispersing machine such as a coball mill;
Wet type jet mill ("Genus PY" manufactured by Genus, "Starburst" manufactured by Sugino Machine, "Nanomizer" manufactured by Nanomizer, etc.), "Crea SS-5" manufactured by M Technic, or "Micro medialess disperser such as
Alternatively, roll mills, kneaders, etc. may be used, but are not limited to these. As the wet mixing device, it is preferable to use one subjected to treatment to prevent metal contamination from the device.

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

<Dispersant>
In addition, when each raw material is not uniformly dissolved in a system, in order to improve the wettability and dispersibility of each raw material in a solvent, a general water-based dispersant or solvent-based dispersant is added together to disperse. , can be mixed.

<Aqueous Dispersant>
Commercially available aqueous dispersants include, but are not limited to, the following.

Dispersants manufactured by BYK-Chemie include DISPERBYK-180, 184, 187, 190, 191, 192, 193, 194, 199, 2010, 2012, 2015, 2096 and the like.

Dispersants manufactured by Lubrizol Japan include SOLSPERSE 12000, 20000, 27000, 41000, 41090, 43000, 44000, or 45000.

Dispersants manufactured by BASF Japan include JONCRYL67, 678, 586, 611, 680, 682, 683, 690, 60, 61, 62, 63, HPD-96, Luvitec K17, K30, K60, K80, K85, K90. , VA64, and the like.

Dispersants manufactured by Kawaken Fine Chemicals Co., Ltd. include Hinoact A-110, 300, 303, and 501.

Examples of dispersants manufactured by Nittobo Medical Co., Ltd. include PAA series, PAS series, amphoteric series PAS-410C, 410SA, 84, 2451, and 2351.

Dispersants manufactured by ISP Japan include polyvinylpyrrolidone PVP K-15, K-30, K-60, K-90, K-120, and the like.

Dispersants manufactured by Maruzen Petrochemical Co., Ltd. include polyvinylimidazole PVI and the like.

<Dispersant for solvent system>
Commercially available solvent-based dispersants are not particularly limited, but include, for example, the following.

Dispersants manufactured by BYK Chemie include Anti-Terra-U, U100, 204, DISPERBYK-101, 102, 103, 106, 107, 108, 109, 110, 111, 140, 161, 163, 168, 170, 171. etc.

Dispersants manufactured by Lubrizol Japan include SOLSPERSE 3000, 5000, 9000, 13240, 13650, 13940, 17000, 18000, 19000, 21000, 22000, 24000SC, 24000GR, 26000, 28000, 31845, 32000, 325000, 3265000, , 34750, 35100, 35200, 36600, 37500, 38500, or 53095.

Dispersants manufactured by Ajinomoto Fine-Techno Co., Inc. include Ajisper PB821, PB822, PN411, or PA111.

Dispersants manufactured by Kawaken Fine Chemicals include Hinoact KF-1000, 1300M, 1500, T-6000, 8000, 8000E and 9100.

Luvicap etc. are mentioned as a dispersing agent by BASF Japan.

<Carbonization, heat treatment>
Next, in the method of heat-treating a mixture of a carbonaceous raw material and a compound containing a hetero element and/or a base metal element, depending on the raw material carbon material and the compound containing the hetero element and/or the base metal element, heating The temperature is preferably 500-1100°C, more preferably 700-1000°C.
In this case, heat treatment at a relatively high temperature often stabilizes the structure of the active sites, resulting in a surface that can withstand practical battery operating conditions. The temperature at this time is preferably 600° C. or higher.

Although the heating time is not particularly limited, it is usually preferably from 1 hour to 5 hours.

Furthermore, regarding the atmosphere in the heat treatment process, it is necessary to carbonize the raw material by incomplete combustion as much as possible and leave the hetero element and metal element on the surface of the carbon material. or a reducing gas atmosphere in which hydrogen is mixed with argon. In addition, in order to suppress the reduction of the amount of hetero elements in the carbon catalyst during heat treatment, the heat treatment is performed in an ammonia gas atmosphere containing a large amount of nitrogen element, and in order to control the surface structure of the carbon catalyst, water vapor, carbon dioxide , the heat treatment may be performed in a low-oxygen atmosphere. In this case, depending on the atmosphere, if the oxidation progresses, the metal becomes an oxide and the particle components tend to aggregate, so it is necessary to appropriately select the temperature, time, and the like.

Regarding the heat treatment process, in addition to the method of performing treatment in one step under a constant atmosphere and temperature, heat treatment is performed once at a relatively low temperature of about 500 ° C. in an inert gas atmosphere, and then an inert gas is used. It is also possible to heat-treat at temperatures above the first step in atmosphere, in a reducing gas atmosphere, or in an activating gas atmosphere. By doing so, active site sites composed of hetero elements and metal elements, which are considered as catalytic active sites, may be left more efficiently and in large amounts.

<Washing, drying>
The method for producing the biofuel cell anode catalyst ink material further includes a process of washing the biofuel cell anode catalyst ink material obtained by the heat treatment with an acid and drying. The acid used here is not particularly limited as long as it can dissolve base metal components that do not act as active sites present on the surface of the biofuel cell anode catalyst ink material obtained by the heat treatment. Concentrated hydrochloric acid, dilute sulfuric acid, etc., which have low reactivity with the biofuel cell anode catalyst ink material and strong dissolving power for base metal components, are preferred. As a specific cleaning method, an acid is added into a glass container, a catalyst ink material for a biofuel cell anode is added, the mixture is stirred for several hours while being dispersed, and the mixture is allowed to stand and the supernatant is removed. Then, the above method is repeated until the supernatant is no longer colored, and finally, the acid is removed by filtering and washing with water, followed by drying.

The method for producing the biofuel cell anode catalyst ink material further includes a step of heat-treating the biofuel cell anode catalyst ink material obtained by the acid washing. The heat treatment here is not much different from the conditions of the previous heat treatment. The heating temperature is preferably 500-1100°C, more preferably 700-1000°C. In addition, from the viewpoint that the nitrogen element on the surface is difficult to decompose and decrease, the atmosphere is an inert gas atmosphere such as nitrogen or argon, a reducing gas atmosphere in which hydrogen is mixed with an inert gas, or an atmosphere of ammonia containing a large amount of nitrogen element. A gas atmosphere or the like is preferable.

<Catalyst ink composition for biofuel cell anode>
The catalyst ink composition for a biofuel cell anode of the present invention can be used for forming an electrode of a biofuel cell anode. The biofuel cell anode catalyst ink composition contains at least the biofuel cell anode catalyst ink material and a binder resin.
The mass ratio of the catalyst ink material to the binder resin is not particularly limited as long as an anode reaction can be obtained, but it is preferably 50:50 to 99:1, more preferably 65:35 to 95:5. be.
The biofuel cell anode catalyst ink composition of the present invention may contain a dispersant and a solvent.
When a dispersing agent is contained, it is 0.01 to 10% by mass, preferably 0.05 to 8% by mass, more preferably 0.05 to 8% by mass of the solid content of the entire biofuel cell anode catalyst ink. It is 1 to 5% by mass.
When a solvent is contained, it is 1 to 9900% by mass, preferably 5 to 1900% by mass, more preferably 25% by mass, based on 100% by mass of the solid content of the entire biofuel cell anode catalyst ink. ~400% by mass.
The appropriate viscosity of the catalyst ink composition for a biofuel cell anode depends on the coating method of the composition, but is generally preferably 10 mPa·s or more and 30,000 mPa·s or less.

<Binder resin>
Next, the binder resin will be explained. By using a binder resin, it is possible to strongly bind the catalyst ink materials for a biofuel cell anode to each other and to the base material, so that good power generation characteristics and durability can be improved.
Examples of binder resins include polyurethane-based resins, polyamide-based resins, acrylonitrile-based resins, acrylic-based resins, butadiene-based resins, polyvinyl butyral-based resins, polyolefin-based resins, polyester-based resins, polystyrene-based resins, EVA-based resins, and polyvinylidene fluoride-based resins. At least one selected from the group consisting of resins, silicon-based resins, and the like can be included. However, the binder resin is not limited to these resins, and one type of binder resin may be used alone, or two or more types may be used in combination.
As such a binder resin, a solvent-based resin dissolved in an organic solvent and used, or a water-based resin dissolved or dispersed in water can be used.
The binder resin can also be a curable resin that undergoes a curing (crosslinking) reaction after preparing a biofuel cell anode catalyst ink composition in which a carbon material and a binder resin are mixed. As the binder resin, a self-curing one may be selected or combined with a curing agent to be described later, and the catalyst ink composition may be cured (crosslinked) after being applied onto the substrate.

The case of using as a solvent-based resin dissolved in an organic solvent will be described.

<Polyurethane resin>
The method for synthesizing the polyurethane resin is not particularly limited. to obtain a urethane prepolymer (d) having an isocyanate group, or further reacting the urethane prepolymer (d) with a polyamino compound (e), or in the above three cases, reacting as necessary Examples thereof include those obtained by reacting with a terminating agent.

As the polyol compound (a), various polyether polyols, polyester polyols, polycarbonate polyols, polybutadiene glycols, or mixtures thereof, which are generally known as polyol components constituting polyurethane resins, can be used.

The number average molecular weight (Mn) of the polyol compound is appropriately determined in consideration of the solubility of the polyurethane resin when producing the catalyst ink composition, the durability and binding strength of the formed anode, and the like. is preferably in the range of 580-8000, more preferably 1000-5000.
The above polyol compounds may be used alone or in combination of two or more. Further, part of the polyol compound can be replaced with low-molecular-weight diols, such as various low-molecular-weight diols used in the production of the polyol compound, as long as the performance of the polyurethane resin is not lost.

As the diisocyanate compound (b), an aromatic diisocyanate, an aliphatic diisocyanate, an alicyclic diisocyanate, or a mixture thereof can be used, and isophorone diisocyanate is particularly preferred.

Examples of the diol compound (c) having a carboxyl group include dimethylolalkanoic acids such as dimethylolacetic acid, dimethylolpropionic acid, dimethylolbutanoic acid and dimethylolpentanoic acid, dihydroxysuccinic acid and dihydroxybenzoic acid. Dimethylolpropionic acid and dimethylolbutanoic acid are particularly preferred from the viewpoint of reactivity and solubility.
The conditions for reacting the polyol compound (a), the diisocyanate (b), and the diol compound (c) having a carboxyl group to obtain a urethane prepolymer (d) having an isocyanate group are, in addition to excessive isocyanate groups, Although not particularly limited, the isocyanate group/hydroxyl equivalent ratio is preferably in the range of 1.05/1 to 3/1. It is more preferably 1.2/1 to 2/1. The reaction is usually carried out at room temperature to 150.degree. C., preferably at 60 to 120.degree. C. in terms of production time and control of side reactions.

The polyamino compound (e) functions as a chain extender and includes ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, isophoronediamine, dicyclohexylmethane-4,4'-diamine, norbornanediamine, and 2 -(2-Aminoethylamino) ethanol, 2-hydroxyethylethylenediamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxypropylethylenediamine and other amines having a hydroxyl group can also be used. can. Among them, isophoronediamine is preferably used.

When synthesizing a polyurethane resin by reacting the urethane prepolymer (d) having an isocyanate group with the polyamino compound (e), a reaction terminator can be used in combination to adjust the molecular weight of the resulting polyurethane resin. As the reaction terminator, dialkylamines such as di-n-butylamine, dialkanolamines such as diethanolamine, and alcohols such as ethanol and isopropyl alcohol can be used.

The conditions for reacting the urethane prepolymer (d) having an isocyanate group, the polyamino compound (e), and, if necessary, the reaction terminator are not particularly limited, but the free isocyanate possessed at both ends of the urethane prepolymer The total equivalent weight of the amino groups in the polyamino compound (e) and the reaction terminator is preferably in the range of 0.5 to 1.3 when the group is taken as 1 equivalent. More preferably, it is within the range of 0.8 to 0.995.
The weight average molecular weight of the polyurethane resin is preferably in the range of 5,000 to 200,000.

When synthesizing polyurethane resin, one or two selected from ester-based solvents, ketone-based solvents, glycol ether-based solvents, aliphatic-based solvents, aromatic-based solvents, alcohol-based solvents, carbonate-based solvents, water, etc. Any combination of the above can be used.

<Polyamide resin>
The polyamide resin used in the present invention is basically a general term for polymers having amide bonds obtained by various reactions such as polycondensation of dibasic acid and diamine, polycondensation of aminocarboxylic acid, or ring-opening polymerization of lactam. , including various modified polyamides, products made from partially hydrogenated reactants, products partially copolymerized with other monomers, or mixed with other substances such as various additives It is a broad concept that includes things.

The polyamide resin used in the present invention is not particularly limited as long as the above conditions are satisfied, but a dimer acid-modified polyamide resin obtained by condensation polymerization of a dibasic acid containing dimer acid as a main component and polyamines is preferable. . Dimer acid obtained by polymerizing natural monobasic unsaturated fatty acids contained in tall oil fatty acid, soybean oil fatty acid, etc. is widely used industrially as the dimer acid for producing dimer acid-modified polyamide resin. may be saturated aliphatic, unsaturated aliphatic, alicyclic or aromatic dicarboxylic acids.
In addition to the above dimer acid, various dicarboxylic acids can be used as the dibasic acid in order to obtain a polyamide resin having suitable flexibility.

Further, a dibasic acid having a phenolic hydroxyl group can also be used. By using a dibasic acid having a phenolic hydroxyl group, a phenolic hydroxyl group can be introduced into the side chain of the polyamide resin and used for reaction with the curing agent.

Furthermore, various monocarboxylic acids are used as necessary in order to obtain a polyamide resin having suitable fluidity when heated.
Examples of polyamines as reactants in producing the dimer acid-modified polyamide resin include various diamines such as aliphatic, alicyclic and aromatic diamines, triamines and polyamines.

<Water-based resin>
Next, the case where it is used as a water-based resin will be described. Examples of water-based resins include water-soluble resins that are used by dissolving them in water, and water-based resin fine particles that are used by dispersing water-insoluble resin fine particles in water (generally called aqueous emulsions). These resins can also be used singly or in combination.

The water-soluble resin is not particularly limited as long as it is a resin exhibiting water solubility as described above. Examples include acrylic resins, polyurethane resins, polyester resins, phenol resins, epoxy resins, polyvinyl alcohol derivatives, xanthan gum derivatives, Guar gum derivatives, chitosan derivatives, cellulose derivatives, alginic acid, alginic acid derivatives, cornstarch derivatives and the like. Modified products, mixtures, or copolymers of these resins may also be used as long as they are water-soluble. These water-soluble resins can also be used singly or in combination.
Although the molecular weight of the water-soluble resin is not particularly limited, it preferably has a weight average molecular weight of 5,000 to 2,500,000. A weight average molecular weight (Mw) indicates a polyethylene oxide equivalent molecular weight in gel permeation chromatography (GPC).

Examples of aqueous resin fine particles include (meth)acrylic emulsions, nitrile emulsions, urethane emulsions, diene emulsions (styrene-butadiene rubber (SBR), etc.), fluorine emulsions (polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), etc.). Unlike water-soluble polymers, emulsions preferably have excellent adhesion between particles and excellent flexibility (flexibility of membranes).

(Particle structure of aqueous resin fine particles)
Moreover, the particle structure of the aqueous resin fine particles used in the present invention can be a multi-layer structure, that is, a so-called core-shell particle. For example, by localizing a resin obtained by mainly polymerizing a monomer having a functional group in the core or shell, or by providing a difference in Tg or composition between the core and the shell, curability and drying can be improved. properties, film formability, and mechanical strength of the binder can be improved.

(Particle diameter of aqueous resin fine particles)
The average particle size of the aqueous resin fine particles used in the present invention is preferably 10 to 500 nm, more preferably 10 to 300 nm, from the viewpoint of binding properties and particle stability. Also, if a large amount of coarse particles exceeding 1 μm is contained, the stability of the particles is impaired, so the content of coarse particles exceeding 1 μm is preferably 5% or less. The average particle size in the present invention means volume average particle size, which can be measured by a dynamic light scattering method.

Measurement of the average particle size by the dynamic light scattering method can be performed as follows. The crosslinked resin fine particle dispersion is diluted with water 200 to 1000 times depending on the solid content. About 5 ml of the diluted solution is injected into a cell of a measuring device [Microtrac manufactured by Nikkiso Co., Ltd.], and the solvent (water in the present invention) and the refractive index conditions of the resin are input according to the sample, and then the measurement is performed. The peak of the volume particle size distribution data (histogram) obtained at this time is taken as the average particle size of the present invention.

<(Meth)acrylic emulsion>
Next, the (meth)acrylic emulsion will be described. The (meth)acrylic emulsion is an emulsion polymer containing 10 parts by mass or more, preferably 20 parts by mass or more, more preferably 30 parts by mass or more of a monomer having a (meth)acryloyl group. Good. Since a monomer having an acryloyl group is excellent in reactivity, resin fine particles can be produced relatively easily. In addition, the (meth)acrylic emulsion anode has excellent binding properties.

<Method for Producing Crosslinked Resin Fine Particles in (Meth)Acrylic Emulsion Suitable for Use in the Present Invention>
The crosslinkable resin fine particles in the (meth)acrylic emulsion suitably used in the present invention are synthesized by a conventionally known emulsion polymerization method.

<Emulsifier used in emulsion polymerization>
As the emulsifier used in emulsion polymerization in the present invention, conventionally known emulsifiers such as reactive emulsifiers having ethylenically unsaturated groups and non-reactive emulsifiers having no ethylenically unsaturated groups can be arbitrarily used. can.

<Other materials used in the reaction>
Further, if necessary, buffering agents such as sodium acetate, sodium citrate, sodium bicarbonate, etc., and chain transfer agents such as octyl mercaptan, 2-ethylhexyl thioglycolate, octyl thioglycolate, stearyl mercaptan, lauryl mercaptan. , and t-dodecylmercaptan can be used in appropriate amounts.

When a monomer having an acidic functional group such as a carboxyl group-containing ethylenically unsaturated monomer is used in the polymerization of the crosslinkable resin fine particles in the (meth)acrylic emulsion preferably used in the present invention, or can be neutralized with a basic compound after polymerization. When neutralizing, it can be neutralized with ammonia or alkylamines such as trimethylamine, triethylamine and butylamine; alcoholamines such as 2-dimethylaminoethanol, diethanolamine, triethanolamine and aminomethylpropanol; and bases such as morpholine. . However, highly volatile bases are highly effective for drying, and preferred bases are aminomethylpropanol and ammonia.

<Solvent>
Next, the solvent will be explained. When uniformly mixing the materials in the catalyst ink composition for a biofuel cell anode, a solvent can be used as appropriate. Examples of such solvents include organic solvents and water.
Organic solvents include alcohols such as methanol, ethanol, propanol, butanol, ethylene glycol methyl ether and diethylene glycol methyl ether, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, tetrahydrofuran, dioxane, ethylene glycol dimethyl ether and diethylene glycol dimethyl ether. and other ethers, hydrocarbons such as hexane, heptane and octane, aromatics such as benzene, toluene, xylene and cumene, and esters such as ethyl acetate and butyl acetate, depending on the composition of the catalyst ink composition. Any suitable one can be used. Moreover, you may use 2 or more types of solvents.
When water is used, for example, a liquid medium compatible with water may be used in order to improve the dispersibility of the catalyst ink composition and the coatability of the catalyst ink composition onto the substrate.
Liquid media compatible with water include alcohols, glycols, cellosolves, aminoalcohols, amines, ketones, carboxylic acid amides, phosphoric acid amides, sulfoxides, carboxylic acid esters, and phosphate esters. , ethers, nitriles, etc., and may be used as long as they are compatible with water.

Furthermore, the catalyst ink composition for the biofuel cell anode may optionally contain a conductive agent, a thickener, a dispersant, a film-forming agent, an antifoaming agent, a leveling agent, a preservative, a pH adjuster, and the like. can.

<Method for preparing catalyst ink composition for biofuel cell anode>
The method for preparing the catalyst ink composition for a biofuel cell anode is not particularly limited. The preparation method is
(1) each component may be dispersed at the same time,
(2) After dispersing the carbon material in the solvent, another material may be added,
(3) Other materials may be added after dispersing the carbon material and the binder resin in the solvent,
It can be selected according to the carbon material, binder resin, and solvent used.

<Disperser/Mixer>
Dispersers and mixers that are commonly used for dispersing pigments and the like can be used as apparatuses for obtaining the catalyst ink composition for biofuel cell anodes.

For example, mixers such as Disper, Homomixer, or Planetary Mixer; Homogenizers such as M Technic's "Clairmix" or PRIMIX's "Filmix"; Paint conditioner (manufactured by Red Devil), ball mill, sand mill (“Dyno Mill” manufactured by Shinmaru Enterprises Co., Ltd.), Attritor, Pearl Mill (“DCP Mill” manufactured by Eirich Co., etc.), media-type dispersing machines such as coball mills; wet jet mills (“Genus PY” manufactured by Genus Co., Ltd., Sugino "Starburst" manufactured by Machine Co., Ltd., "Nanomizer" manufactured by Nanomizer, etc.), "Crea SS-5" manufactured by M Technic Co., Ltd., or "MICROS" manufactured by Nara Machinery Co., Ltd. Medialess disperser; or other roll mills, etc. Examples include, but are not limited to.

For example, when using a media-type disperser, a disperser whose agitator and vessel are made of ceramic or resin, or a disperser whose metal agitator and vessel surface are treated with tungsten carbide spraying or resin coating. is preferably used. As media, it is preferable to use glass beads, zirconia beads, or ceramic beads such as alumina beads. Also when using a roll mill, it is preferable to use ceramic rolls. Only one type of dispersing device may be used, or a plurality of types of devices may be used in combination. When the catalyst-carrying carbon material is likely to crack or crush due to strong impact, a medialess disperser such as a roll mill or homogenizer is preferable to a media type disperser.

<Bio fuel cell anode>
A biofuel cell anode can be produced by coating a substrate with a catalyst ink composition for a biofuel cell anode to form a coating film.

<Base material>
As the base material used in the anode of the present invention, those having excellent corrosion resistance, excellent electrical conductivity, large surface area, and excellent diffusion of reactants and products are preferred, and the material and shape are not particularly limited. For example, in addition to carbon materials such as graphite paper (carbon paper), graphite cloth (carbon cloth) and graphite felt (carbon felt), metal materials such as stainless steel mesh, copper mesh and platinum mesh can be used, but as far as this Absent. The conductive base material used for the electrode may be subjected to a water-repellent treatment in advance. For example, the cathode is impregnated with a PTFE dispersion, dried, and then heated at around 400° C. to exhibit water repellency. Also, a conductive material may be dispersed in the PTFE dispersion. Note that the water-repellent treatment is not limited to these.

<Coating method>
The method of applying the catalyst ink composition for a biofuel cell anode of the present invention to a substrate is not particularly limited, and known methods can be used. Examples include gravure coating, spray coating, screen printing, dip coating, die coating, roll coating, doctor coating, knife coating, screen printing or electrostatic coating. As a drying method, drying by standing, a blow dryer, a hot air dryer, an infrared heater, a far-infrared heater, etc. can be used, but the method is not particularly limited to these.

<Bio fuel cell device>
The biofuel cell device of the present invention comprises the biofuel cell anode, the biofuel cell cathode, and a fuel containing reducing organic matter. A separator and an ionic conductor may be included as necessary.

<Biofuel cell cathode>
The biofuel cell cathode can be produced by a conventionally known method or the same material composition and process as those of the anode, except that an oxygen reduction catalyst is used.
As the oxygen reduction catalyst, a known catalyst used in biofuel cell cathodes can be used.

<Fuel>
The fuel used in the biofuel cell of the present invention contains one or more reducible organics that are directly oxidizable on the electrode. Examples include ascorbic acid, ascorbic acid derivatives, erythorbic acid, erythorbic acid derivatives, nicotinamide adenine dinucleotide, nicotinamide adenine dinucleotide derivatives, nicotinamide adenine dinucleolin acid, citric acid, tartaric acid and the like. Here, the derivatives include condensates with alcohols and amines such as acid esters and acid amides, as well as those substituted with substituents such as alkyl groups.
Among them, ascorbic acid, erythorbic acid, nicotinamide adenine dinucleotide, nicotinamide adenine dinucleophosphate, and derivatives thereof are preferred, and ascorbic acid is more preferred.

<Separator>
The separator is not particularly limited as long as it can electrically separate the cathode and the anode (prevention of short circuit), and conventionally known materials can be used. Specifically, polyethylene fiber, polypropylene fiber, glass fiber, resin nonwoven fabric, glass nonwoven fabric, felt, filter paper, Japanese paper, and the like can be used. Also, if the cathode and the anode maintain a sufficient distance and take a structure that does not cause a short circuit due to contact, the separator may not be used.

<Ionic conductor>
The ionic conductor in the present invention conducts ions between the anode and the cathode. The form of the ionic conductor is not particularly limited as long as it has ionic conductivity. As the ionic conductor, for example, an electrolytic solution in which an electrolyte is dissolved in a liquid such as a phosphate buffer, or a solid polymer electrolyte may be used. A solid polymer electrolyte may also serve as a separator.

<Uses of biofuel cell devices>
As described above, the biofuel cell device using a reducing organic substance as a fuel in the present invention functions as a power source using the generated power, a self-powered sensor that serves as both a power source and a sensor, an organic substance sensor, a moisture sensor, etc. It is expected to be used for various purposes. As for usage, a battery of another type (coin battery, etc.) is used as a power source, a biofuel cell device using the reducing organic substance of the present invention as a fuel is used as a sensor, or the reducing organic substance of the present invention is used as a power source and a sensor. It is also possible to use one or more types of fuel cell devices, or a biofuel cell device using the reducing organic substance of the present invention as a power source and a sensor of another type as a sensor.

Examples of power applications of biofuel cells using reducing organic matter as fuel in the present invention include household power sources, power sources for mobile devices, disposable power sources, wearable power sources/implant power sources for living organisms, power sources for biomass fuels, and IoT sensors. Examples include a power source, an energy harvesting power source that can generate power using the surrounding reducing organic matter as fuel, and the like.

Sensor applications include, for example, organic sensors for reducing organic substances, biosensors for reducing organic substances in biological samples such as blood, sweat, urine, feces, tears, saliva, and exhaled breath, and body fluids. Moisture sensor for food, food sensor for reducing organic matter in fruits and food, IoT sensor, environmental sensor for reducing organic matter in the environment such as air, rivers, soil, animals, insects, plants The above may be a self-powered sensor that serves as both a power source and a sensor, or may be used only as a sensor that does not use it as a power source. Examples of biosensors include perspiration sensors and urination sensors that sense moisture in sweat and urine. Also, examples of applications as wearable sensors for living organisms include urination sensors in which sensors are embedded in diapers and skin-attached perspiration sensors.

As an IoT sensor, it can be used by combining a wireless device and a sensor to wirelessly transmit sensing information to the outside. In that case, a fuel cell device using the reducing organic substance of the present invention as a fuel can be suitably used.

For example, using a biofuel cell device using reducing organic matter as fuel for the power source and sensor of a wireless device, or using a biofuel cell device using reducing organic matter as fuel for the power source of a wireless device and another reducing organic matter as a sensor. Using a biofuel cell device as fuel, using a biofuel cell device using reducing organic matter as a power source for a wireless device, using a different type of sensor as a sensor, or using one or more types of power sources for wireless devices and sensors A biofuel cell device using reducing organic matter as fuel, using a different type of sensor as a sensor, or using a different type of battery (coin battery, etc.) for the power supply of a wireless device, biofuel using reducing organic matter as a sensor A battery device can be used.

When the above IoT sensor is used as a biosensor for diapers, a biofuel cell device that uses reducing organic matter as a fuel is installed in the diaper, and the following uses are possible. In the case of a urination sensor, fuel is built in beforehand and moisture in urine is used as a sensing target. With the power obtained, the wireless device and another type of urination sensor are operated, or the moisture in the urine is detected by incorporating fuel in advance, and the wireless device is operated with the power of another type of battery (coin battery, etc.). can.

The present invention will be described in more detail below with reference to examples. Unless otherwise specified, parts and % represent parts by mass and % by mass, and Mw means weight average molecular weight in terms of polystyrene.

<Synthesis Example (1) Binder Resin Solution>
Polyester polyol obtained from terephthalic acid, adipic acid and 3-methyl-1,5-pentanediol (manufactured by Kuraray Co., Ltd. 455.5 parts of "Kuraray Polyol P-2011", Mn = 2011), 16.5 parts of dimethylolbutanoic acid, 105.2 parts of isophorone diisocyanate, and 140 parts of toluene are charged and reacted at 90°C for 3 hours in a nitrogen atmosphere. 360 parts of toluene was added to obtain a urethane prepolymer solution having an isocyanate group. Next, 19.9 parts of isophoronediamine, 0.63 parts of di-n-butylamine, 294.5 parts of 2-propanol, and 335.5 parts of toluene were mixed, and the resulting urethane prepolymer solution having an isocyanate group was obtained. 969.5 parts was added, reacted at 50° C. for 3 hours and then at 70° C. for 2 hours, diluted with 126 parts of toluene and 54 parts of 2-propanol, Mw = 61,000, acid value = 10 mgKOH/g, urethane pre- A polyurethane resin solution was obtained in which the total equivalent weight of the amino groups in the polyamino compound and the reaction terminator was 0.98 with respect to the free isocyanate groups at both ends of the polymer. This solution was diluted with toluene/methyl ethyl ketone/2-propanol (1/1/1) to obtain a solution of binder resin (1) having a solid content of 20%.

<Catalyst ink material for biofuel cell anode>
[Example A1]
Graphene nanoplatelets xGnP-C-750 (manufactured by XGscience) are filled in an alumina crucible and heat treated at 1000 ° C. for 2 hours in an ammonia atmosphere in an electric furnace to obtain a catalyst ink material for a biofuel cell anode (1 ).

[Example A2]
After preparing a uniform aqueous solution by weighing 90 parts of ion-exchanged water and 5 parts of iron (II) chloride tetrahydrate in a glass bottle, add 5 parts of graphene nanoplatelet xGnP-C-750 (manufactured by XGscience), and further. After adding zirconia beads as a medium, they were dispersed with a paint shaker (manufactured by Mitsuwa Tech Co., Ltd.: Scandex SK450) to obtain a precursor mixed paste. This precursor mixed paste was distilled off under reduced pressure using a rotary evaporator, and the obtained solid content was finely pulverized using a mortar to obtain a uniform precursor powder. The obtained precursor powder was filled in an alumina crucible and heat treated at 800° C. for 2 hours in an electric furnace under a nitrogen atmosphere to obtain a biofuel cell anode catalyst ink material (2).

[Example A3]
Ketjenblack EC-600JD (manufactured by Lion Specialty Chemicals Co., Ltd.) and cobalt phthalocyanine (manufactured by Tokyo Kasei Co., Ltd.) were weighed so that the mass ratio was 1/0.75 (Ketjenblack/cobalt phthalocyanine), respectively, and dried. Mixing was performed to obtain a mixture. The mixture was filled in an alumina crucible and heat-treated at 800° C. for 2 hours in an electric furnace in a nitrogen atmosphere to obtain a biofuel cell anode catalyst ink material (3).

[Example A4]
A phenolic resin (PSM-4326 manufactured by Gunei Chemical Co., Ltd.) and iron phthalocyanine P-26 (manufactured by Sanyo Color Co., Ltd.) were weighed at a mass ratio of 3.3:1 and wet-mixed in acetone. After distilling off the above mixture under reduced pressure, the residue was pulverized in a mortar to obtain a precursor. The above precursor powder was filled in an alumina crucible and heat treated at 600° C. for 2 hours in an electric furnace in a nitrogen atmosphere to obtain a carbon sintered body (1). The carbon sintered body (1) was reslurried in concentrated hydrochloric acid and allowed to stand. After the carbon sintered body (1) precipitated, the supernatant liquid was removed. The above operation is repeated until the supernatant is no longer colored, filtered, washed with water, dried, pulverized in a mortar, filled in an alumina crucible, heat treated in an electric furnace at 800 ° C. for 1 hour in an ammonia atmosphere, and charcoal fired. Result (2) was obtained. The carbon sintered body (2) was reslurried in concentrated hydrochloric acid and allowed to stand. After the carbon sintered body precipitated, the supernatant liquid was removed. After repeating the above operation until the coloration of the supernatant disappeared, it was filtered, washed with water, dried and pulverized in a mortar to obtain a biofuel cell anode catalyst ink material (4).

[Example A5]
Polyvinylpyridine (manufactured by Aldrich) was dissolved in dimethylformamide, iron chloride hexahydrate was added in a mass ratio of 4:1 to polyvinylpyridine, and the mixture was stirred at room temperature for 24 hours to obtain a polyvinylpyridine iron complex. The above polyvinylpyridine iron complex is filled in an alumina crucible and heat-treated at 800° C. for 2 hours in an electric furnace under a nitrogen atmosphere. (5) was obtained.

[Example A6]
Graphene nanoplatelets xGnP-C-750 (manufactured by XGscience) and iron phthalocyanine P-26 (manufactured by Sanyo Color Co., Ltd.) were weighed so that the mass ratio was 1/0.75 (graphene nanoplatelets/iron phthalocyanine). and dry-blended to obtain a mixture. The above mixture was filled in an alumina crucible and heat-treated at 800° C. for 2 hours in an electric furnace under a nitrogen atmosphere to obtain a biofuel cell anode catalyst ink material (6).

[Example A7]
Carbon nanotubes VGCF-H (manufactured by Showa Denko KK) and cobalt phthalocyanine (manufactured by Tokyo Chemical Industry Co., Ltd.) were weighed so that the mass ratio was 1/0.1 (carbon nanotubes/cobalt phthalocyanine), and dry-mixed to form a mixture. got The mixture was filled in an alumina crucible and heat-treated at 800° C. for 2 hours in an electric furnace in a nitrogen atmosphere to obtain a biofuel cell anode catalyst ink material (7).

[Example A8]
90 parts of ion-exchanged water, 3.4 parts of iron (II) chloride tetrahydrate, and 0.2 parts of phthalocyanine (manufactured by Tokyo Chemical Industry Co., Ltd.) were weighed into a glass bottle to prepare a uniform aqueous solution, and then graphene nanoplatelets xGnP- After adding 6.4 parts of C-750 (manufactured by XGscience) and further adding zirconia beads as media, the mixture was dispersed with a paint shaker (manufactured by Mitsuwa Tech Co., Ltd.: Scandex SK450) to obtain a precursor mixed paste. This precursor mixed paste was distilled off under reduced pressure using a rotary evaporator, and the obtained solid content was finely pulverized using a mortar to obtain a uniform precursor powder. The obtained precursor powder was filled in an alumina crucible and heat treated at 800° C. for 2 hours in an electric furnace under a nitrogen atmosphere to obtain a biofuel cell anode catalyst ink material (8).

[Example A9]
90 parts of ion-exchanged water, 1.5 parts of iron (II) chloride tetrahydrate, and 1.5 parts of phthalocyanine (manufactured by Tokyo Chemical Industry Co., Ltd.) were weighed into a glass bottle to prepare a uniform aqueous solution, followed by acetylene black HS-100 ( Denka Co., Ltd.) was added, and zirconia beads were added as media, followed by dispersion with a paint shaker (Mitsuwatec Co., Ltd.: Scandex SK450) to obtain a precursor mixed paste. This precursor mixed paste was distilled off under reduced pressure using a rotary evaporator, and the obtained solid content was finely pulverized using a mortar to obtain a uniform precursor powder. The obtained precursor powder was filled in an alumina crucible and heat-treated at 800° C. for 2 hours in an electric furnace under a nitrogen atmosphere to obtain a biofuel cell anode catalyst ink material (9).

[Example A10]
Porous carbon Knobel MJ (4) 150 (manufactured by Toyo Tanso Co., Ltd.) and copper phthalocyanine derivative SOLSPERSE 12000 (manufactured by Nippon Lubrizol Co., Ltd.) were weighed so that the mass ratio was 1/1 (Cnobel / copper phthalocyanine), and dry mixed. to obtain a mixture. The above mixture was filled in an alumina crucible and heat-treated at 800° C. for 2 hours in an electric furnace in a nitrogen atmosphere to obtain a biofuel cell anode catalyst ink material (10).

The analysis of the catalyst ink material for the biofuel cell anode described above used the following measurement equipment. Table 1 shows the results.
・ Measurement of BET specific surface area: Measurement of nitrogen adsorption amount (BELSORP-mini manufactured by Bell Japan)
- _RC , RN, RM: CHN elemental analysis (2400 model CHN elemental analyzer manufactured by PerkinElmer), ICP emission spectroscopic analysis ( _{SPECTROARCOS FHS12} manufactured by SPECTRO)
In addition, it was confirmed by X-ray diffraction (XRD) measurement using CuKα rays as an X-ray source that the catalyst ink materials (1) to (10) for a biofuel cell anode had a basic skeleton of a carbon hexagonal mesh plane.

<Preparation of catalyst ink composition for biofuel cell anode using reducing organic matter as fuel>
[Example B1]
60 parts of catalyst ink material (1) for biofuel cell anode, 40 parts of emulsion-type acrylic resin dispersion solution (Toyochem: W-168) as binder resin (solid content: 50%), 380 parts of water as solvent, further thickening As an agent, 20 parts of an aqueous carboxymethyl cellulose solution was added to a mixer, mixed, and dispersed in a sand mill to obtain a biofuel cell anode catalyst ink composition (1) using a reducing organic substance as a fuel.

[Examples B2 to B10, Comparative Examples B1 to B3]
Using the materials shown in Table 2, in the same manner as in Example B1, biofuel cell anode catalyst ink compositions (2) to (10) and (I) to (III) using reducing organic matter as fuel were obtained. rice field.

<Preparation of biofuel cell anode using reducing organic matter as fuel>
[Examples C1 to C10, Comparative Examples C1 to C3]
The biofuel cell anode catalyst ink compositions (1) to (10) and (I) to (III) of Examples B1 to B10 and Comparative Examples B1 to B3 using reducing organic matter as fuel were dried with a doctor blade. It is coated on a conductive substrate (carbon paper, manufactured by Toray Industries, Inc.) so that the basis weight of the subsequent biofuel cell anode catalyst layer using reducing organic matter as fuel is 1.5 mg/cm ² , and the catalyst is heated in an oven at 100°C. After drying for 1 hour, biofuel anodes (1) to (10) and (I) to (III) using reducing organic matter as fuel were produced.

<Evaluation of power generation characteristics of biofuel cell anode using reducing organic matter (ascorbic acid) as fuel>
A biofuel cell anode using the reducing organic substance prepared above shown in Table 3 as a working electrode, a platinum wire coil as a counter electrode, an Ag/AgCl electrode as a reference electrode, and ascorbic acid as a reducing organic fuel is 10 mM. An electrochemical cell was produced using a 100 mM phosphate buffer (pH 7.0) added as an electrolyte. Next, using a potentio-galvanostat, at room temperature, Linear Sweep Voltammetry (LSV) measurement is performed in the range of measurement potential -0.1 to +0.1 V, and the current (μA/cm ² ) was calculated. Table 3 shows the evaluation results.

<Preparation of biofuel cell cathode using reducing organic matter (ascorbic acid) as fuel>
A catalyst ink for a biofuel cell cathode was produced in the same manner as in Example B1, except that the catalyst ink material for the biofuel cell anode in Example B1 was changed to Ketjenblack EC-600JD (manufactured by Lion Specialty Chemicals). Then, a biofuel cell cathode was produced in the same manner as in Example C1.

<Preparation of biofuel cell using reducing organic matter as fuel>
[Examples D1 to D10, Comparative Examples D1 to D3]
The biofuel cell cathode and biofuel cell anode prepared above, and the 100 mM phosphate buffer (pH 7.0) to which ascorbic acid, which is a reducing organic fuel, was added so as to be 10 mM were soaked into the filter paper as an electrolyte. Biofuel cells (1) to (10) and (I) to (III) using reducing organic matter as fuel are produced by sandwiching a separator between the cathode and the anode, and the output characteristics are measured by LSV measurement at room temperature. evaluated. The output characteristics were compared by the percentage (%) of the maximum output in each example with respect to the maximum output in Comparative Example 1 calculated from the LSV measurement, and evaluated according to the following criteria.
A: Percentage of maximum output relative to Comparative Example 1 is 300% or more.
◯: Percentage of maximum output relative to Comparative Example 1 is 200% or more and less than 300%.
◯Δ: Percentage of maximum output relative to Comparative Example 1 is 150% or more and less than 200%.
Δ: Percentage of maximum output relative to Comparative Example 1 is 100% or more and less than 150%.
x: Percentage of maximum output relative to Comparative Example 1 is less than 100%.

From the results of Examples C1 to C10, it was clarified that good output characteristics were exhibited compared to the comparative examples. It is thought that good catalytic properties could be realized for
On the other hand, from the results of Examples D1 to D10, it was also revealed that they operate as biofuel cells exhibiting better output characteristics than those of Comparative Examples.

Claims (5)

A catalyst ink material for a fuel cell anode, which is made of a carbon material having a carbon hexagonal mesh plane as a basic skeleton and uses a reducing organic substance as a fuel,
The carbon material contains a hetero element and/or a base metal element as a constituent element, and is doped so that at least part of the carbon element in the carbon skeleton is substituted with the hetero element. A reducing organic substance. catalyst ink material for biofuel cell anodes fueled by A biofuel cell anode catalyst ink composition using a reducing organic substance as fuel, comprising the biofuel cell anode catalyst ink material according to claim 1 and a binder resin. A biofuel cell anode using a reducing organic substance as a fuel, having a coating film formed from the catalyst ink composition for a biofuel cell anode according to claim 2 . A biofuel cell device comprising the biofuel cell anode of claim 3, a biofuel cell cathode, and a fuel comprising reducible organics. The claim characterized in that the reducing organic substance is one or more selected from the group consisting of ascorbic acid, ascorbic acid derivatives, erythorbic acid, erythorbic acid derivatives, nicotinamide adenine dinucleotide, and nicotinamide adenine dinucleotide derivatives. 5. The biofuel cell device according to 4.