Composite material, method for manufacturing composite material, catalyst, dispersion, electrode, and electrolysis device

Abstract

This composite material comprises a carbon material and a zinc phthalocyanine halide fixed on the surface of the carbon material.

Description

Composite material, method for producing composite material, catalyst, dispersion, electrode, and electrolysis device

[0001] The present disclosure relates to a composite material, a method for producing a composite material, a catalyst, a dispersion, an electrode, and an electrolysis device.

[0002] Carbon materials are used in a wide range of applications due to their properties such as high electrical conductivity, high thermal conductivity, low thermal expansion coefficient, light weight, and heat resistance, and are also used, for example, as catalysts for the positive electrodes of fuel cells and air batteries. The use of carbon materials as supports for such catalysts has also been investigated, and it has been reported, for example, that composite materials formed by supporting a metal phthalocyanine compound such as iron phthalocyanine on a carbon material can function as oxygen reduction catalysts (see, for example, Non-Patent Documents 1 and 2).

[0003] International Publication No. 2021 / 220495

[0004] RCS Adv. , 2016, 6, 67049-67056. NPG Asia Materials, 11, Article number: 57 (2019).

[0005] As described above, it has been confirmed that carbon materials and composite materials using carbon materials have oxygen reduction activity. However, in any of these materials, the oxygen reduction activity is predominantly activity for the four-electron reduction reaction of oxygen, and activity for the two-electron reduction reaction of oxygen is insufficient.

[0006] An object of one aspect of the present disclosure is to provide a composite material having sufficient catalytic activity for the two-electron reduction reaction of oxygen.

[0007] Some aspects of the present disclosure provide the following [1] to

[14] .

[0008] [1] A composite material comprising a carbon material and a halogenated zinc phthalocyanine adhered to the surface of the carbon material.

[0009] [2] The composite material according to [1], wherein the halogenated zinc phthalocyanine has at least one of a bromine atom and a chlorine atom as a halogen atom.

[0010] [3] The composite material according to [1] or [2], wherein the halogenated zinc phthalocyanine has an average halogen number of 4 or more.

[0011] [4] The composite material according to any one of [1] to [3], wherein the carbon material comprises at least one selected from the group consisting of carbon nanotubes, carbon black, and activated carbon.

[0012] [5] The composite material according to any one of [1] to [4], wherein the content of the halogenated zinc phthalocyanine is 50 parts by mass or less relative to 100 parts by mass of the carbon material.

[0013] [6] The composite material according to any one of [1] to [5], having an electrical conductivity of 0.01 S / cm or more.

[0014] [7] A method for producing the composite material according to any one of [1] to [6], comprising a step of adhering a material containing the halogenated zinc phthalocyanine to the carbon material, the step comprising a step of mixing the carbon material with a solution or dispersion containing the material and a liquid medium.

[0015] [8] A catalyst for use in a two-electron reduction reaction of oxygen, comprising the composite material according to any one of [1] to [6].

[0016] [9] A dispersion liquid containing the composite material according to any one of [1] to [6] and a dispersion medium for the composite material.

[0017]

[10] The dispersion according to [9], containing a polymer electrolyte.

[0018]

[11] The dispersion according to [9] or

[10] , which is used for forming an electrode catalyst layer.

[0019]

[12] An electrode comprising an electrode catalyst layer containing the composite material according to any one of [1] to [6].

[0020]

[13] The electrode according to

[12] , wherein the electrode catalyst layer contains a polymer electrolyte.

[0021]

[14] An electrolysis device comprising the electrode according to

[12] or

[13] .

[0022] According to one aspect of the present disclosure, a composite material having sufficient catalytic activity for a two-electron reduction reaction of oxygen can be provided.

[0023] In this specification, a numerical range indicated using "to" indicates a range that includes the numerical values ​​written before and after "to" as the minimum and maximum values, respectively. Furthermore, unless specifically stated otherwise, the units of the numerical values ​​written before and after "to" are the same. In the numerical ranges described in stages in this specification, the upper limit or lower limit of a numerical range in a certain stage may be replaced with the upper limit or lower limit of a numerical range in another stage. Furthermore, in the numerical ranges described in this specification, the upper limit or lower limit of the numerical range may be replaced with the value shown in the Examples (Experimental Examples). Furthermore, the upper limit and lower limit values ​​described individually can be combined in any combination.

[0024] Preferred embodiments of the present disclosure will be described below, but the present disclosure is not limited to the following embodiments.

[0025] One embodiment of the present disclosure is a composite material including a carbon material and a halogenated zinc phthalocyanine adhered to the surface of the carbon material. Here, "composite" means that the halogenated zinc phthalocyanine is adhered to the carbon material by physical or chemical adsorption.

[0026] In the above composite material, the carbon material can also be said to be a support that supports the halogenated zinc phthalocyanine, i.e., the above composite material can also be said to include a support containing a carbon material and the halogenated zinc phthalocyanine supported on the support.

[0027] The composite material has sufficient catalytic activity for the two-electron reduction reaction of oxygen (hereinafter referred to as "two-electron reduction activity"). Therefore, the composite material is used, for example, as a cathode catalyst in an oxygen decomposition device. The catalytic activity for the two-electron reduction reaction of oxygen can be confirmed by the method described in the Examples (Experimental Examples).

[0028] (Carbon material) The carbon material is a material that mainly contains carbon, and the carbon content in the carbon material is 60% by mass or more. The carbon material content can be measured by CHN elemental analysis using a combustion method. The carbon material content may be 70% by mass or more, or 80% by mass or more.

[0029] The carbon material is a so-called solid carbon material, and can be, for example, nanocarbons such as fullerenes, carbon nanotubes, graphene, and graphene oxide; three-dimensional crystals such as diamond and graphite; amorphous carbons such as activated carbon and carbon black; and fibrous carbons such as carbon fibers and carbon nanofibers. Examples of carbon black include furnace black, channel black, acetylene black, thermal black, and ketjen black. Among these, when the carbon material contains at least one selected from the group consisting of carbon nanotubes, carbon black, graphite, carbon fibers, carbon nanofibers, and graphene, the composite material tends to have good electrical conductivity. Furthermore, when the carbon material contains at least one selected from the group consisting of carbon nanotubes, carbon black, and activated carbon, even better two-electron reduction activity is more likely to be obtained.

[0030] The carbon material may be a powder material composed of a plurality of carbon particles, or may be a non-powder material (e.g., a sheet composed of carbon fibers). The shape of the carbon particles may be, for example, spherical, sheet-like, fibrous, or the like. The median diameter of the powdered carbon material may be, for example, 0.01 to 50 μm, or 0.01 to 10 μm. The median diameter is the D50 particle size measured using a laser diffraction particle size distribution analyzer equipped with an airflow dry disperser.

[0031] The average particle size of the carbon material may be, for example, 0.01 to 1 μm, 0.35 μm or less, or 0.1 μm or less, or 0.05 μm or more. In particular, when the average particle size of the carbon material is 0.01 to 0.35 μm, better oxygen reduction activity tends to be easily obtained. The average particle size is the average particle size of primary particles (average primary particle size), and can be calculated by ultrasonically dispersing a sample in cyclohexane, photographing it with a microscope, and averaging the values ​​of 40 primary particles constituting the aggregates on a two-dimensional image.

[0032] The carbon material may be porous, i.e., may be a porous carbon material (for example, a powdered porous carbon material).

[0033] The specific surface area of ​​the carbon material measured by the BET single-point method (BET specific surface area) is, for example, 50 to 3000 m ２ / g, and 100m ２ / g or more, 200m ２ / g or more or 300m ２ / g or more, and ２ / g or less or 1000m ２ The BET specific surface area is a value measured by a nitrogen adsorption method, and can be measured, for example, using a fully automatic specific surface area measuring device Macsorb HM model-1208 (manufactured by Mountec Co., Ltd.) in accordance with the "Method for measuring gas adsorption amount by a single-point method" specified in Appendix 2 of Japanese Industrial Standards JIS Z8830-1990.

[0034] The conductivity of the carbon material may be 0.01 S / cm or more, 0.10 S / cm or more, 1.00 S / cm to 5.00 S / cm or more, or 10.00 S / cm or more. From the viewpoint of improving the reaction efficiency at the electrode, the conductivity may be 0.01 to 100.00 S / cm. From the same viewpoint, the conductivity may be 50.00 S / cm or less, or 30.00 S / cm or less. The conductivity is a value measured by powder resistance measurement using, for example, an automatic powder resistance measurement system (MCP-PD600 model, manufactured by Nitto Seiko Analytech Co., Ltd.). As the automatic powder resistivity measurement system, for example, one comprising a low-resistivity probe unit, an automatic hydraulic pump, a main body control unit, and a low resistivity meter Loresta GX (MCP-T700 model, manufactured by Nitto Seiko Analytech Co., Ltd.) can be used. After placing a carbon material in the low-resistivity probe unit, the volume resistivity [Ω cm] (the reciprocal of the electrical conductivity [S / cm]) can be determined by measuring the volume resistivity when a load of 12 kN is applied.

[0035] (Halogenated Zinc Phthalocyanine) The halogenated zinc phthalocyanine has a structure represented by the following formula (1).

[0036]

[0037] X in formula (1) １ ~X １６ each independently represents a hydrogen atom or a halogen atom. １ ~X １６ At least one of the groups is a halogen atom. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms.

[0038] From the viewpoint of easily obtaining better two-electron reduction activity, the halogenated zinc phthalocyanine may have at least one halogen atom selected from the group consisting of a fluorine atom, a bromine atom, and a chlorine atom. From the viewpoint of easily obtaining even better two-electron reduction activity, the halogenated zinc phthalocyanine may have at least one of a bromine atom and a chlorine atom. From the viewpoint of easily obtaining even better two-electron reduction activity, the halogenated zinc phthalocyanine may have a bromine atom. From the viewpoint of easily obtaining particularly better two-electron reduction activity, the halogenated zinc phthalocyanine may have only one atom selected from the group consisting of a fluorine atom, a bromine atom, and a chlorine atom, or may have only one or both of a bromine atom and a chlorine atom. That is, X in the above formula (1) １ ~X １６ may be a fluorine atom, a bromine atom, or a chlorine atom, or may be a bromine atom or a chlorine atom. In this specification, a halogenated zinc phthalocyanine having only fluorine atoms as halogen atoms may be referred to as a "fluorinated zinc phthalocyanine," a halogenated zinc phthalocyanine having only chlorine atoms as halogen atoms may be referred to as a "chlorinated zinc phthalocyanine," and a halogenated zinc phthalocyanine having only bromine atoms and chlorine atoms as halogen atoms may be referred to as a "brominated chlorinated zinc phthalocyanine."

[0039] The halogenated zinc phthalocyanine to be fixed to the carbon material may be one type or a plurality of types.

[0040] The average halogen number of the halogenated phthalocyanine compound, i.e., the average total number of halogen atoms in the halogenated zinc phthalocyanine (total number of halogen atoms per molecule) is greater than 0, and from the viewpoint of more easily obtaining superior two-electron reduction activity, may be 4 or more (for example, 4 to 16), 11 or more, or 15 or less, or 14 or less.

[0041] The average number of fluorine atoms in the halogenated phthalocyanine compound, i.e., the average number of fluorine atoms in the halogenated zinc phthalocyanine (the number of fluorine atoms per molecule), is 0 or more, and from the viewpoint of more easily obtaining superior two-electron reduction activity, may be 4 or more (for example, 4 to 16), 5 or more, 8 or more, or 11 or more, and may be 15 or less, or 13 or less.

[0042] The average bromine number of the halogenated phthalocyanine compound, i.e., the average number of bromine atoms in the halogenated zinc phthalocyanine (the number of bromine atoms per molecule), is 0 or more, and from the viewpoint of more easily obtaining superior two-electron reduction activity, may be 4 or more (for example, 4 to 16), 5 or more, 8 or more, or 11 or more, and may be 15 or less, or 13 or less.

[0043] The average number of chlorine atoms in the halogenated phthalocyanine compound, i.e., the average number of chlorine atoms in the halogenated zinc phthalocyanine (the number of chlorine atoms per molecule), is 0 or more, and from the viewpoint of more easily obtaining superior two-electron reduction activity, may be more than 0 and 11 or less, 0.1 or more, 0.5 or more, or 1 or more, or may be 3 or less, or 2 or less.

[0044] The number of halogen atoms can be determined by mass analysis using, for example, a matrix-assisted laser desorption / ionization time-of-flight mass spectrometer (such as JMS-S3000 manufactured by JEOL Ltd.). Specifically, the number of each halogen atom can be calculated as a relative value per central metal element from the mass ratio of the central metal element to each halogen atom in the halogenated zinc phthalocyanine.

[0045] The halogenated zinc phthalocyanine may be formed in a layer shape so as to coat the surface of the carbon material. In other words, the composite material may include a carbon material and a coating layer containing the halogenated zinc phthalocyanine adhered to the surface of the carbon material. The thickness of the coating layer may be, for example, 0.1 to 50 nm.

[0046] The halogenated zinc phthalocyanine may be adhered to the surface of the carbon material in the form of particles. In other words, the composite material may include a carbon material and particles of the halogenated zinc phthalocyanine adhered to the surface of the carbon material. The size of the particles of the halogenated zinc phthalocyanine adhered to the surface of the carbon material (the major axis of the primary particles) may be 300 nm or less (e.g., 10 to 300 nm), 200 nm or less, 100 nm or less, 70 nm or less, 60 nm or less, or 40 nm or less, or 40 nm or more, or 70 nm or more. The aspect ratio of the particles of the halogenated zinc phthalocyanine may be, for example, 1.0 to 3.0. The average size (average particle diameter) of all particles adhered to the surface of the carbon material may be within the above range (average major axis of the primary particles), and the average aspect ratio of all particles (average aspect ratio) may be within the above range.

[0047] The content of the halogenated zinc phthalocyanine in the composite material may be 50 parts by mass or less relative to 100 parts by mass of the carbon material, from the viewpoint of more easily obtaining superior two-electron reduction activity. The content of the halogenated zinc phthalocyanine in the composite material may be 0.01 parts by mass or more relative to 100 parts by mass of the carbon material, from the viewpoint of more easily obtaining superior two-electron reduction activity. From the same viewpoint, the content of the halogenated zinc phthalocyanine in the composite material may be 1 part by mass or more or 5 parts by mass or more, 30 parts by mass or less, 15 parts by mass or less, or 0.01 to 50 parts by mass, 1 to 30 parts by mass, or 5 to 15 parts by mass, relative to 100 parts by mass of the carbon material.

[0048] In the composite material, the component fixed to the carbon material (for example, the component to be supported) may be only the halogenated zinc phthalocyanine, but a component other than the halogenated zinc phthalocyanine may also be fixed to the carbon material. Examples of such fixed components (for example, supported components) include zinc phthalocyanine having no halogen substituent (X in formula (1) １ ~X １６ are all hydrogen atoms).

[0049] The total amount (total content) of the carbon material and the halogenated zinc phthalocyanine contained in the composite material may be 50% by mass or more, 80% by mass or more, or 90% by mass or more, based on the total mass of the composite material. The total amount (total content) of the carbon material and the halogenated zinc phthalocyanine contained in the composite material may be 100% by mass, 99% by mass or less, or 95% by mass or less, based on the total mass of the composite material.

[0050] The composite material may have a shape corresponding to the shape of the carbon material. That is, the composite material may be in a powder form, and the average particle size of the composite material (D50 particle size measured by dynamic light scattering particle size distribution measurement) may be, for example, 0.01 to 10 μm.

[0051] The specific surface area of ​​the composite material measured by the BET single-point method (BET specific surface area) is, for example, 1 to 3000 m ２ / g, and 50m ２ / g or more or 400m ２ / g or more, and ２ / g or less or 1000m ２ The BET specific surface area is a value measured by a nitrogen adsorption method, and can be measured in the same manner as the specific surface area of ​​the carbon material described above.

[0052] The composite material may be electrically conductive. Specifically, the conductivity of the composite material may be 0.01 S / cm or more. The conductivity may be 0.10 S / cm or more, 1.00 S / cm to 5.00 S / cm or more, or 10.00 S / cm or more. From the viewpoint of improving the reaction efficiency at the electrode, the conductivity may be 0.01 to 100.00 S / cm. From the same viewpoint, the conductivity may be 50.00 S / cm or less, or 30.00 S / cm or less. The conductivity can be determined by measuring in the same manner as the conductivity of the carbon material described above.

[0053] <Method for Producing Composite Material> Another embodiment of the present disclosure is a method for producing a composite material, including a step of fixing a material containing a halogenated zinc phthalocyanine to a carbon material (fixing step).

[0054] According to the above method, the composite material of the above embodiment can be obtained. That is, according to the above method, a composite material having excellent catalytic activity for the two-electron reduction reaction of oxygen can be provided.

[0055] The above-mentioned adhesion step can also be referred to as a step of supporting a material containing at least a halogenated zinc phthalocyanine on a carbon material (supporting step). Methods for adhering a material containing a halogenated zinc phthalocyanine to a carbon material can include known support methods used in the production of supported catalysts (e.g., impregnation, deposition, coprecipitation, kneading, ion exchange, pore filling, etc.). Among these, a method of mixing a carbon material with a solution or dispersion containing a material containing a halogenated zinc phthalocyanine and a liquid medium can efficiently prepare a composite material, and it is easy to adjust the amounts of the carbon material and halogenated zinc phthalocyanine contained in the composite material to the desired amounts. This effect is more easily achieved by ultrasonicating the mixture obtained by the above-mentioned mixing (e.g., the methods described in Non-Patent Documents 1 and 2). The liquid medium may be an aprotic polar organic medium such as tetrahydrofuran, dimethyl sulfoxide, or ethyl acetate, or a protic polar organic medium such as ethanol or diethylene glycol. These may be used alone or in combination. Among these, from the viewpoint of more easily obtaining a composite material having superior two-electron reduction activity, an aprotic polar organic medium may be used, and from the viewpoint of more easily obtaining a composite material having even superior two-electron reduction activity, at least one selected from the group consisting of dimethyl sulfoxide and ethyl acetate may be used.

[0056] In the above method, the amounts of the carbon material and the halogenated zinc phthalocyanine used may be adjusted so that the total amount of the carbon material and the halogenated zinc phthalocyanine contained in the composite material and the content of the halogenated zinc phthalocyanine in the composite material are within the above-mentioned ranges.

[0057] The halogenated zinc phthalocyanine is, for example, in powder form. The average particle size (average major axis of the primary particles) of the powder made of halogenated zinc phthalocyanine may be 300 nm or less (e.g., 10 to 300 nm), 200 nm or less (e.g., 10 to 200 nm), 100 nm or less (e.g., 10 to 100 nm), 70 nm or less (e.g., 10 to 70 nm), 60 nm or less (e.g., 10 to 60 nm), or 40 nm or less (e.g., 10 to 40 nm), or 40 nm or more (e.g., 40 to 200 nm) or 70 nm or more (e.g., 70 to 200 nm). In particular, the average particle size of the powder made of halogenated zinc phthalocyanine may be 10 to 3.0. The average aspect ratio of the powder made of halogenated zinc phthalocyanine may be, for example, 1.0 to 3.0. Powders having such average particle sizes and average aspect ratios can be produced, for example, by methods described in International Publication No. WO 2021 / 220495.

[0058] The material containing a halogenated zinc phthalocyanine may contain components other than the above-mentioned halogenated zinc phthalocyanine, and the content of the components may be 20% by mass or less, 5% by mass or less, or 1% by mass or less, based on the total mass of the material.

[0059] (Catalyst) Another embodiment of the present disclosure is a catalyst (e.g., an electrode catalyst) comprising the composite material of the above embodiment. This catalyst is a two-electron reduction catalyst that catalyzes the two-electron reduction reaction of oxygen, and tends to exhibit superior catalytic activity when used as a cathode catalyst in an oxygen electrolysis device. In particular, the catalyst of this embodiment tends to exhibit superior catalytic activity when used under basic conditions.

[0060] (Dispersion) Another embodiment of the present disclosure is a dispersion containing the composite material of the above embodiment and a dispersion medium for the composite material. This dispersion is used for forming an electrode catalyst layer, etc. That is, one aspect of the dispersion is an ink composition for forming an electrode catalyst layer.

[0061] As described above, the composite material of the above embodiment can function as a two-electron reduction catalyst, and therefore the dispersion is useful for forming a cathode catalyst layer of an electrolyzer (oxygen electrolysis device).

[0062] As the dispersion medium, known dispersion media used in forming the electrode catalyst layer of the electrolysis device can be used. For example, water, lower alcohols (methanol, ethanol, isopropyl alcohol, normal propyl alcohol, etc.), and mixtures thereof can be used. The content of the dispersion medium may be appropriately adjusted so that the viscosity of the dispersion liquid is suitable for the coating device. The content of the dispersion medium in the dispersion liquid may be, for example, 60 to 99.5 mass% based on the total mass of the dispersion liquid.

[0063] The dispersion may be composed of only the composite material and the dispersion medium, or may contain, in addition to these, known materials used to form the cathode catalyst layer of the electrolyzer (oxygen electrolysis device). The dispersion may further contain, for example, a binder for the composite material. Known organic polymer compounds can be used as the binder, and a polymer electrolyte may be used from the viewpoint of forming an ion conduction path. Examples of the polymer electrolyte include perfluorosulfonic acid polymers such as Nafion (registered trademark).

[0064] When the dispersion contains solids other than the composite material (for example, the binder), the content of the composite material may be 40 to 80 mass % based on the total amount of solids in the dispersion. The content of the binder in the dispersion may be 20 to 60 mass % based on the total amount of solids in the dispersion. When the dispersion contains a polymer electrolyte, the content of the polymer electrolyte may be 20 to 60 mass % based on the total amount of solids in the dispersion. The total amount of solids refers to the total amount of components other than the dispersion medium contained in the dispersion.

[0065] (Electrode) Another embodiment of the present disclosure is an electrode including an electrode catalyst layer containing the composite material of the above embodiment. This electrode is, for example, the cathode of an electrolyzer (oxygen electrolysis device). The configuration of the electrode other than the electrode catalyst layer may be a conventionally known configuration for the cathode of such a device. The electrode of one embodiment may further include, for example, a gas diffusion layer, a microporous layer, etc.

[0066] The electrode catalyst layer may be composed only of the composite material, or may contain components other than the composite material depending on the application. Examples of components other than the composite material include binders such as the polymer electrolytes described above. The ranges of the contents of the composite material, binder, and polymer electrolyte in the electrode catalyst layer (based on the total mass of the electrode catalyst layer) may be the same as the ranges of the contents of the composite material, binder, and polymer electrolyte in the dispersion of the above embodiment (based on the total solid content in the dispersion).

[0067] The electrode catalyst layer can be formed using the dispersion liquid of the above embodiment. For example, the electrode catalyst layer can be obtained by applying the dispersion liquid to a support and drying it. The application method is not particularly limited, and a general method such as using a bar coater, a spray coater, or a screen printer can be used.

[0068] (Electrolysis Device) Another embodiment of the present disclosure is an electrolysis device including the electrode of the above embodiment. This electrolysis device is an oxygen electrolysis device and includes the electrode of the above embodiment as an oxygen reduction electrode (cathode). The oxygen electrolysis device can also be called a hydrogen peroxide synthesis device because it synthesizes hydrogen peroxide through the decomposition of oxygen. The configuration of the cell other than the cathode may be a conventionally known configuration for an oxygen electrolysis device.

[0069] The contents of the present disclosure will be explained in more detail below using experimental examples, but the present disclosure is not limited to the following experimental examples.

[0070] <Method for Measuring the Number of Halogen> The number of halogens (average number of bromine and average number of chlorine) of the materials used in the experimental examples was determined by mass spectrometry using a JMS-S3000 manufactured by JEOL Ltd.

[0071] <Method for measuring average particle size> The average particle size (average primary particle size) of the material used in the experimental examples was calculated from the average value of 40 primary particles constituting the aggregates on a two-dimensional image of the material, which was ultrasonically dispersed in cyclohexane and then photographed under a microscope.

[0072] <Method for measuring BET specific surface area> The BET specific surface area of ​​the materials and composite materials used in the experimental examples was measured by nitrogen adsorption. The measurement was performed using a fully automatic specific surface area measuring device, Macsorb HM model-1208 (manufactured by Mountec Co., Ltd.), in accordance with the "Method for measuring gas adsorption amount by the single-point method" specified in Appendix 2 of the Japanese Industrial Standard JIS Z8830-1990.

[0073] <Method of Measuring Electrical Conductivity> The electrical conductivity of the materials and composite materials used in the experimental examples was measured using an automatic powder resistivity measurement system (MCP-PD600 model, manufactured by Nitto Seiko Analytech Co., Ltd.). The automatic powder resistivity measurement system used was composed of a low-resistance probe unit, an automatic hydraulic pump, a main body control unit, and a low-resistivity meter Loresta GX (MCP-T700 model, manufactured by Nitto Seiko Analytech Co., Ltd.). After placing the carbon material in the low-resistance probe unit, the volume resistivity [Ω cm] was measured when a load of 12 kN was applied, and the reciprocal of this was taken as the electrical conductivity [S / cm].

[0074] Experimental Example 1 (Preparation of Composite Material) As raw material 1, C.I. Pigment Green 58 (brominated chlorinated zinc phthalocyanine powder, average bromine number: 11 to 16, average chlorine number: 0 to 5, average particle size: 10 to 60 nm, “BrCl-ZnPc(A)” in Table 1) manufactured by DIC Corporation was prepared, and as raw material 2, Carbon ECP (trade name, carbon black manufactured by Lion Specialty Chemicals Co., Ltd., BET specific surface area: 813 m) was prepared. ２ / g, conductivity: 29.36 S / cm) was prepared.

[0075] Next, a composite material of Experimental Example 1 was prepared using the above-mentioned raw material 1 (BrCl-ZnPc(A)) and the above-mentioned raw material 2 (carbon ECP). Specifically, 20 mg of raw material 1 (BrCl-ZnPc(A)) and 200 mL of dimethyl sulfoxide (DMSO), a liquid medium, were added to a 450 mL glass bottle to prepare a mixed solution. The resulting mixed solution was then subjected to ultrasonic treatment at 31 kHz for 30 minutes or more using a Honda Electronics tabletop ultrasonic cleaner W-113MKII. The ultrasonically treated mixed solution was then stirred for 30 minutes or more using a stirrer piece. 200 mg of raw material 2 (carbon ECP) ​​was added to the stirred mixed solution, and the mixture was stirred at 1000 rpm for 30 minutes or more. The mixture was then filtered, washed with ethanol, and vacuum dried. This resulted in a composite material containing a carbon material (carbon black) and brominated chlorinated zinc phthalocyanine adhered to the surface of the carbon material.

[0076] Experimental Examples 2 to 4 Composite materials of Experimental Examples 2 to 4 were prepared in the same manner as Experimental Example 1, except that Raw Material 1 and Raw Material 2 were used in the mass ratio shown in Table 1.

[0077] Experimental Example 5 A composite material of Experimental Example 5 was produced in the same manner as Experimental Example 1, except that C.I. Pigment Green 59 (brominated chlorinated zinc phthalocyanine powder, average bromine number: 8 to 13, average chlorine number: 0 to 5, average particle size: 10 to 60 nm, “BrCl—ZnPc(B)” in Table 1) manufactured by DIC Corporation was used as Raw Material 1.

[0078] Experimental Example 6: A 300 ml flask was charged with 91 g of sulfuryl chloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 109 g of aluminum chloride (manufactured by Kanto Chemical Co., Ltd.), 15 g of sodium chloride (manufactured by Tokyo Chemical Industry Co., Ltd.), and 30 g of zinc phthalocyanine (manufactured by DIC Corporation). The mixture was then heated to 130°C and maintained at 130°C for 4 hours. The reaction mixture (reaction solution) was poured into water to precipitate a precipitate. The precipitate was then filtered, washed with water, and dried to obtain a crude pigment powder. 12 g of the crude pigment powder, 240 g of Japanese seawater salt (manufactured by Nihon Kaisui Co., Ltd.), and 35 g of diethylene glycol were charged into a double-arm kneader and kneaded at 80°C for 18 hours. The resulting mixture was then poured into 700 g of water. After stirring for 1 hour, the mixture was filtered, washed with hot water, dried, and pulverized to obtain chlorinated zinc phthalocyanine (a powder of zinc phthalocyanine having chlorine atoms as a substituent, average number of chlorines: 8 to 13, average particle size: 10 to 60 nm, "Cl-ZnPc" in Table 1).

[0079] A composite material of Experimental Example 6 was produced in the same manner as in Experimental Example 1, except that the chlorinated zinc phthalocyanine obtained above was used as Raw Material 1.

[0080] Experimental Example 7 As raw material 2, multi-walled carbon nanotubes (trade name: carbon nanotubes manufactured by Tokyo Chemical Industry Co., Ltd., product code: C2152, diameter 10-30 nm, length 5-15 μm, BET specific surface area: 98 m) were used. ２ A composite material of Experimental Example 7 was prepared in the same manner as in Experimental Example 1, except that a cellulose acylate polymer (polyethylene glycol stearate, cellulose acetate ...

[0081] <Experimental Example 8> As raw material 2, activated carbon (powder) (trade name: activated carbon manufactured by Kanto Chemical Co., Ltd., product number: 01085-02, BET specific surface area: 668 m ２ A composite material of Experimental Example 8 was prepared in the same manner as in Experimental Example 1, except that a cellulose acylate polymer (polyethylene glycol stearate, cellulose acetate ...

[0082] Experimental Example 9 A composite material of Experimental Example 9 was produced in the same manner as in Experimental Example 1, except that zinc 1,2,3,4,8,9,10,11,15,16,17,18,22,23,24,25-hexadecafluoro-29H,31H-phthalocyanine (fluorinated zinc phthalocyanine powder, product code: 444529, average fluorine atoms: 11 to 16, average particle size: 50 to 100 nm, “F-ZnPc” in Table 1) manufactured by Sigma-Aldrich Corporation was used as Raw Material 1.

[0083] Experimental Example 10 A composite material of Experimental Example 10 was produced in the same manner as Experimental Example 1, except that iron phthalocyanine ("FePc" in Table 1, manufactured by Tokyo Chemical Industry Co., Ltd., iron (II) phthalocyanine, product code: P0774) was used as Raw Material 1.

[0084] Experimental Example 11 A composite material of Experimental Example 11 was produced in the same manner as Experimental Example 1, except that chlorinated iron phthalocyanine in which all 16 hydrogen atoms were substituted with chlorine atoms ("Cl-FePc" in Table 1, manufactured by Cosmo Bio Co., Ltd., product number 097) was used as Raw Material 1.

[0085] Experimental Examples 12 to 15 Composite materials of Experimental Examples 12 to 15 were produced in the same manner as Experimental Example 1, except that tetrahydrofuran (THF), ethyl acetate (AcOEt), diethylene glycol (DEG), or ethanol (EtOH) was used as the liquid medium for preparing the mixed solution.

[0086] <Evaluation 1: Electrical Conductivity> The electrical conductivity [S / cm] of the composite materials obtained in Experimental Examples 1 to 15 and the carbon ECP was measured using an automatic powder resistivity measurement system (MCP-PD600 manufactured by Nitto Seiko Analytech Co., Ltd.). The automatic powder resistivity measurement system used was comprised of a low-resistance probe unit, an automatic hydraulic pump, a main body control unit, and a low-resistivity meter Loresta GX (MCP-T700 manufactured by Nitto Seiko Analytech Co., Ltd.). After placing the material in the low-resistance probe unit, the volume resistivity [Ω cm] was measured when a load of 12 kN was applied, and the reciprocal of this was taken as the electrical conductivity [S / cm]. The results are shown in Table 1.

[0087] <Evaluation 2: Oxygen reduction activity> The oxygen reduction activity of the composite materials of Experimental Examples 1 to 15 was evaluated by the following method. As a reference example, the oxygen reduction activity of the carbon ECP (carbon black) was also evaluated.

[0088] First, 4.1 mg of composite material or carbon ECP, 1680 μL of IPA (isopropyl alcohol), 420 μL of ultrapure water, and 30 μL of 5% Nafion (Sigma-Aldrich; product number 510211) were weighed into a vial and mixed by ultrasonic irradiation for 5 minutes to obtain a dispersion. 4 μL of the dispersion was dropped onto the disk portion of a platinum ring GC disk electrode (RRDE) (BAS, product number 012613, ring outer diameter: 7.0 mm, ring inner diameter: 5.0 mm, disk outer diameter: 4.0 mm) and allowed to dry for approximately 10 minutes. This was repeated twice, and a total of 8 μL of the dispersion was applied to a measurement catalyst electrode (disk electrode area: 0.126 cm). ２ , catalyst loading: 123 μg / cm ２ ) was obtained.

[0089] Next, an Ag / AgCl electrode (BAS; product number 012167) was used as the reference electrode, and a Pt coil electrode (BAS; product number 012961) was used as the counter electrode, and the oxygen reduction activity of the measurement catalyst electrode was evaluated by a three-electrode electrochemical cell method. ２ The measurement system was stabilized by cycling in a 0.1 M KOH aqueous solution saturated with oxygen (O ２ Linear sweep voltammetry (LSV) measurements were performed on the catalytic electrode for measurement, rotating it at 1600 rpm in a 0.1 M KOH aqueous solution saturated with Ag / AgCl. The LSV measurements were performed by scanning the potential from noble to base potentials in the range of -0.7 to 0.1 V (vs. Ag / AgCl) at 10 mV / s. The potential of the ring electrode was set to 0.2 V (vs. Ag / AgCl), a potential at which hydrogen peroxide can be sufficiently oxidized.

[0090] The voltammogram measured with the Ag / AgCl electrode was converted to the RHE standard using the following formula, and the disk current value I at 0.4 V (vs. RHE) was calculated. Ｄｉｓｋ, ring current value I Ｒｉｎｇ , and reaction onset potential E ｏｎｓｅｔ In the following formula, E ｏｂｓｅｒｖｅｄ is the potential relative to the Ag / AgCl electrode, and E ０ Ａｇ／ＡｇＣｌ The E was 0.195 and the pH was 13.0. ＲＨＥ = E ０ Ａｇ／ＡｇＣｌ +0.0590pH+E ｏｂｓｅｒｖｅｄ

[0091] In addition, to confirm the proportion of two-electron reduction reactions (reactions that generate hydrogen peroxide) among the catalyzed oxygen reduction reactions, the hydrogen peroxide generation rate (% H ２ O ２ The capture efficiency N was calculated by multiplying the outer radius r of the disk electrode by the １ , the inner radius r of the ring part of the ring electrode ２ , and the inner radius r of the ring portion of the ring electrode ３ The values ​​were calculated based on the following formulas (a2) to (a5). ２ O ２ (unit: %) = 2 x I Ｒｉｎｇ / N / (I Ｄｉｓｋ +I Ｒｉｎｇ / N) ...(a1) ・N=1-F(α / β)+β ２／３ [1-F(α)]-(1+α+β) ２／３ {1-F[(α / β)(1+α+β)]} …(a2) ・α=(r ２ / r １ ) ３ -1...(a3) ・β=(r ３ / r １ ) ３ -(r ２ / r １ ) ３ ...(a4) ・F(θ)=[3 １／２ / (4π)]In[(1+θ １／３ ) / (1+θ)]+[3 / (2π)]arctan[(2θ １／３ -1) / 3 １／２ ]+1 / 4...(a5)

[0092] In this evaluation, 0.1 mA / cm ２The potential at which a reduction current of 0.4 V (vs. RHE) flows is defined as the reaction initiation potential, and the disk current value I Ｄｉｓｋ is -1.5mA / cm ２ The reaction initiation potential is 0.5 V or more, and the hydrogen peroxide generation rate (% H ２ O ２ When the ratio of the two-electron reduction activity of the composite material is 50% or more, the composite material is judged to have sufficient two-electron reduction activity, and the disk current value I at 0.4 V (vs. RHE) is Ｄｉｓｋ is -3.0mA / cm ２ The reaction initiation potential is 0.7 V or more, and the hydrogen peroxide generation rate (% H ２ O ２ The composite material was judged to have excellent two-electron reduction activity when the ratio of the two-electron reduction activity to the total carbon dioxide was 65% or more. The results are shown in Table 1.

[0093]

Claims

1. A carbon material and a halogenated zinc phthalocyanine adhered to a surface of the carbon material, A composite material, wherein the halogenated zinc phthalocyanine has a bromine atom and a chlorine atom as halogen atoms.

2. 2. The composite material according to claim 1, wherein the halogenated zinc phthalocyanine has an average halogen number of 4 or more.

3. The composite material according to claim 1 , wherein the carbon material comprises at least one selected from the group consisting of carbon nanotubes, carbon black, and activated carbon.

4. 2. The composite material according to claim 1, wherein the content of the halogenated zinc phthalocyanine is 50 parts by mass or less relative to 100 parts by mass of the carbon material.

5. 2. The composite material of claim 1, having a conductivity of 0.01 S / cm or more.

6. A method for producing the composite material according to any one of claims 1 to 5, comprising the steps of: a step of adhering a material containing the halogenated zinc phthalocyanine to the carbon material, The method for producing a composite material, wherein the step includes a step of mixing a carbon material with a solution or dispersion containing the material and a liquid medium.

7. A catalyst for use in a two-electron reduction reaction of oxygen, comprising: A catalyst comprising the composite material according to any one of claims 1 to 5.

8. A dispersion comprising the composite material according to any one of claims 1 to 5 and a dispersion medium for the composite material.

9. The dispersion of claim 8 containing a polyelectrolyte.

10. The dispersion according to claim 8 , which is used for forming an electrode catalyst layer.

11. An electrode comprising an electrode catalyst layer containing the composite material according to any one of claims 1 to 5.

12. 12. The electrode of claim 11, wherein the electrocatalyst layer comprises a polymer electrolyte.

13. Electrolysis device comprising the electrode according to claim 11.