Composite material, method for producing 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

Technical Field

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

Background Art

[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. For example, they are also used as a positive electrode catalyst for fuel cells and air batteries. In addition, the use of carbon materials as a carrier for such catalysts has also been studied. For example, it has been reported that a composite material obtained by supporting a metal phthalocyanine compound such as iron phthalocyanine on a carbon material can function as an oxygen reduction catalyst (see, for example, Non-Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Non-Patent Documents

[0004]

Non-Patent Document 1

Non-Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] As described above, although it has been confirmed that carbon materials and composite materials using carbon materials have oxygen reduction activity, in any of these materials, as the oxygen reduction activity, the activity for the 4-electron reduction reaction of oxygen is dominant, and the activity for the 2-electron reaction of oxygen is insufficient.

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

Means for Solving the Problems

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

[14] .

[0008] [1] A composite material comprising a carbon material and zinc phthalocyanine halide fixed on the surface of the carbon material.

[0009] [2] The composite material according to [1], wherein the zinc phthalocyanine halide 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 average number of halogens of the zinc phthalocyanine halide is 4 or more.

[0011] [4] The composite material according to any one of [1] to [3], wherein the carbon material contains 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 zinc phthalocyanine halide is 50 parts by mass or less with respect to 100 parts by mass of the carbon material.

[0013] [6] The composite material according to any one of [1] to [5], having a 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 fixing a material containing the zinc phthalocyanine halide to the carbon material. ​ The method for manufacturing a composite material, wherein the step includes mixing a solution or dispersion containing the material and a liquid medium with a carbon material.

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

[0016] [9] A dispersion 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] , used for forming an electrode catalyst layer.

[0019]

[12] An electrode including 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 including the electrode according to

[12] or

[13] .

Advantages of the Invention

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

Modes for Carrying Out the Invention

[0023] In this specification, a numerical range indicated using "~" represents a range that includes the numerical values described before and after "~" as the minimum value and the maximum value, respectively. Also, unless specifically stated otherwise, the units of the numerical values described before and after "~" are the same. In the numerical ranges described stepwise in this specification, the upper limit value or the lower limit value of a certain step's numerical range may be replaced with the upper limit value or the lower limit value of another step's numerical range. Also, in the numerical ranges described in this specification, the upper limit value or the lower limit value of that numerical range may be replaced with the value shown in the examples (experimental examples). Also, the individually described upper limit value and lower limit value can be arbitrarily combined.

[0024] Hereinafter, preferred embodiments of the present disclosure will be described. However, the present disclosure is not limited to the following embodiments in any way.

[0025] <Composite material> One embodiment of the present disclosure is a composite material including a carbon material and zinc phthalocyanine halide fixed on the surface of the carbon material. Here, "composite" means that zinc phthalocyanine halide is fixed by physically or chemically adsorbing to the carbon material.

[0026] In the above composite material, the carbon material can also be said to be a carrier that supports zinc phthalocyanine halide. That is, the above composite material can also be said to include a carrier containing a carbon material and zinc phthalocyanine halide supported on the carrier.

[0027] The above composite material has sufficient catalytic activity for the two-electron reduction reaction of oxygen (hereinafter referred to as "two-electron reduction activity"). Therefore, the above 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 mainly containing carbon, and the carbon content in the carbon material is 60% by mass or more. The content of the carbon material can be measured by CHN elemental analysis using the combustion method. The content of the carbon material 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 examples thereof include nanocarbons such as fullerenes, carbon nanotubes, graphene, and graphene oxide, three-dimensional crystals such as diamond and graphite, amorphous carbon 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 a good conductivity. Further, when the carbon material contains at least one selected from the group consisting of carbon nanotubes, carbon black, and activated carbon, more excellent two-electron reduction activity is likely to be obtained.

[0030] The carbon material may be a powdery material composed of a plurality of carbon particles, or may be a non-powdery (for example, sheet-like composed of carbon fibers) material. The shape of the carbon particles may be, for example, spherical, sheet-like, fibrous, or the like. The median diameter of the powdery carbon material may be, for example, 0.01 to 50 μm, or may be 0.01 to 10 μm. The above median diameter is the D50 particle size measured by a laser diffraction particle size distribution measuring device equipped with an air flow type dry disperser.

[0031] The average particle size of the carbon material may be, for example, 0.01 to 1 μm, may be 0.35 μm or less, or may be 0.1 μm or less, and may also be 0.05 m or more. Among these, when the average particle size of the carbon material is 0.01 to 0.35 μm, there is a tendency to more easily obtain excellent oxygen reduction activity. Note that the average particle size is the average particle size of the primary particles (average primary particle size), and can be calculated from the average value of 40 primary particles constituting the aggregate on the two-dimensional image after ultrasonically dispersing the sample in cyclohexane and then taking a microscope photograph.

[0032] The carbon material may have porosity. That is, the carbon material may be a porous carbon material (for example, a powdery porous carbon material).

[0033] The specific surface area (BET specific surface area) of the carbon material measured by the BET single-point method may be, for example, 50 to 3000 m 2 / g, may be 100 m 2 / g or more, may be 200 m 2 / g or more, or may be 300 m 2 / g or more, and may also be 1500 m 2 / g or less, or may be 1000 m 2 / g or less. The BET specific surface area is a value measured by the nitrogen adsorption method, and can be measured, for example, using a fully automatic specific surface area measuring device Macsorb HM model-1208 (manufactured by Mountech Co., Ltd.) in accordance with the "Method for Measuring Gas Adsorption Amount by the Single-Point Method" specified in Appendix 2 of Japanese Industrial Standard JIS Z8830-1990.

[0034] The conductivity of the carbon material may be 0.01 S / cm or more, and may also be 0.10 S / cm or more, 1.00 S / cm or more, 5.00 S / cm or more, or 10.00 S / cm or more. From the perspective of improving the reaction efficiency at the electrode, the above conductivity may be 0.01 to 100.00 S / cm. From the same perspective, the above conductivity may also be 50.00 S / cm or less or 30.00 S / cm or less. The above conductivity is a value measured by powder resistance measurement using, for example, an automatic powder resistance measurement system (MCP-PD600 type manufactured by Nitto Seiko Analytic). As the automatic powder resistance measurement system, for example, a system composed of a low-resistance probe unit, an automatic hydraulic pump, a main body control unit, and a low-resistance meter Loresta GX (MCP-T700 type manufactured by Nitto Seiko Analytic) can be used. After putting the carbon material into the low-resistance probe unit, it can be obtained by measuring the volume resistivity [Ω·cm] (the reciprocal of the conductivity [S / cm]) when a load of 12 kN is applied.

[0035] (zinc phthalocyanine halide) Zinc phthalocyanine halide has a structure represented by the following formula (1).

[0036] [Chemical formula]

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

[0038] From the perspective that zinc phthalocyanine halide is more likely to obtain excellent two-electron reduction activity, as the halogen atom, it may have at least one selected from the group consisting of a fluorine atom, a bromine atom, and a chlorine atom. From the perspective that zinc phthalocyanine halide is more likely to obtain further excellent two-electron reduction activity, it may have at least one of a bromine atom and a chlorine atom. From the perspective that even further excellent two-electron reduction activity is more likely to be obtained, it may have a bromine atom. From the perspective that particularly excellent two-electron reduction activity is more likely to be obtained, it may have both a bromine atom and a chlorine atom. Zinc phthalocyanine halide may have only any one atom selected from the group consisting of a fluorine atom, a bromine atom, and a chlorine atom as the halogen atom, or may have only one or both of a bromine atom and a chlorine atom. That is, X 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, zinc phthalocyanine halide having only a fluorine atom as the halogen atom may be referred to as "fluorinated zinc phthalocyanine", zinc phthalocyanine halide having only a chlorine atom as the halogen atom may be referred to as "chlorinated zinc phthalocyanine", and zinc phthalocyanine halide having only a bromine atom and a chlorine atom as the halogen atom may be referred to as "brominated chlorinated zinc phthalocyanine".

[0039] The zinc phthalocyanine halide fixed to the carbon material may be one kind or a plurality of kinds.

[0040] The average number of halogens in the halogenated phthalocyanine compound, that is, the average of the total number of halogen atoms in zinc phthalocyanine halide (the total number of halogen atoms per molecule) is greater than 0, and from the perspective that more excellent two-electron reduction activity is more likely to be obtained, it may be 4 or more (for example, 4 to 16), may be 11 or more, and may be 15 or less or 14 or less.

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

[0042] The average number of bromine atoms in the halogenated phthalocyanine compound, that is, the average number of bromine atoms in zinc phthalocyanine halide (the number of bromine atoms per molecule) is 0 or more, and from the viewpoint of easily obtaining more excellent two-electron reduction activity, it may be 4 or more (for example, 4 to 16), may be 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, that is, the average number of chlorine atoms in zinc phthalocyanine halide (the number of chlorine atoms per molecule) is 0 or more, and from the viewpoint of easily obtaining more excellent two-electron reduction activity, it may be greater than 0 and 11 or less, may be 0.1 or more, 0.5 or more, or 1 or more, and may be 3 or less or 2 or less.

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

[0045] Zinc phthalocyanine halide may be formed in layers 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 zinc phthalocyanine halide fixed to the surface of the carbon material. The thickness of the coating layer may be, for example, 0.1 to 50 nm.

[0046] Zinc phthalocyanine halide may be fixed on the surface of the carbon material in a particulate state. In other words, the composite material may include a carbon material and particles composed of zinc phthalocyanine halide fixed on the surface of the carbon material. The size (major axis of the primary particle) of the particles composed of zinc phthalocyanine halide fixed on the surface of the carbon material may be 300 nm or less (for example, 10 to 300 nm), may be 200 nm or less, 100 nm or less, 70 nm or less, 60 nm or less, or 40 nm or less, and may be 40 nm or more or 70 nm or more. The aspect ratio of the particles composed of zinc phthalocyanine halide may be, for example, 1.0 to 3.0. The average of the sizes of all the particles fixed on the surface of the carbon material (average particle diameter) may be within the above range (average value of the major axis of the primary particles), and the average of the aspect ratios of all the particles (average aspect ratio) may also be within the above range.

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

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

[0049] The total amount (total content) of the carbon material and zinc phthalocyanine halide contained in the composite material may be 50% by mass or more, may be 80% by mass or more, or may be 90% by mass or more based on the total mass of the composite material. The total amount (total content) of the carbon material and zinc phthalocyanine halide contained in the composite material may be 100% by mass, may be 99% by mass or less, or may be 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 powder form, and the average particle diameter (D50 particle diameter measured by dynamic light scattering particle size distribution measurement) of the composite material may be, for example, 0.01 to 10 μm.

[0051] The specific surface area (BET specific surface area) of the composite material measured by the BET single-point method may be, for example, 1 to 3000 m 2 / g, may be 50 m 2 / g or more, or may be 400 m 2 / g or more, and may be 1500 m 2 / g or less, or may be 1000 m 2 / g or less. The BET specific surface area is a value measured by the 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 have conductivity. Specifically, the conductivity of the composite material may be 0.01 S / cm or more. The above conductivity may be 0.10 S / cm or more, 1.00 S / cm or more, 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 above conductivity may be 0.01 to 100.00 S / cm. From the same viewpoint, the above conductivity may be 50.00 S / cm or less, or 30.00 S / cm or less. The above conductivity can be obtained by measuring in the same manner as the conductivity of the carbon material described above.

[0053] <Manufacturing method of composite material> Another embodiment of the present disclosure is a method for manufacturing a composite material, including a step of fixing a material containing zinc phthalocyanine halide 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 fixing step can also be referred to as a step of supporting a material containing at least zinc phthalocyanine halide on a carbon material (supporting step). As a method for fixing a material containing zinc phthalocyanine halide to a carbon material, known supporting methods (such as impregnation method, deposition method, coprecipitation method, kneading method, ion exchange method, pore filling method, etc.) used in the production of supported catalysts can be used. Among them, according to the method of mixing a solution or dispersion containing a material containing zinc phthalocyanine halide and a liquid medium with a carbon material, the composite material can be efficiently adjusted, and it is easy to adjust the amounts of the carbon material and zinc phthalocyanine halide contained in the composite material to desired amounts. Such an effect is more easily obtained in the method of subjecting the mixture obtained by the above mixing to ultrasonic treatment (for example, the methods described in Non-Patent Document 1 and Non-Patent Document 2). As the above liquid medium, an aprotic polar organic medium such as tetrahydrofuran, dimethyl sulfoxide, and ethyl acetate may be used, or a protic polar organic medium such as ethanol and diethylene glycol may be used. These may be used alone or in combination of two or more. Among these, from the viewpoint of easily obtaining a composite material having more excellent two-electron reduction activity, an aprotic polar organic medium may be used, and from the viewpoint of more easily obtaining a composite material having more excellent 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 zinc phthalocyanine halide used may be adjusted so that the total amount of the carbon material and zinc phthalocyanine halide contained in the composite material and the content of zinc phthalocyanine halide in the composite material are within the above-described ranges.

[0057] Zinc phthalocyanine halide is, for example, in powder form. The average particle diameter (average value of the major axis of primary particles) of the powder composed of zinc phthalocyanine halide may be 300 nm or less (for example, 10 to 300 nm), may be 200 nm or less (for example, 10 to 200 nm), 100 nm or less (for example, 10 to 100 nm), 70 nm or less (for example, 10 to 70 nm), 60 nm or less (for example, 10 to 60 nm), or 40 nm or less (for example, 10 to 40 nm), and may also be 40 nm or more (for example, 40 to 200 nm) or 70 nm or more (for example, 70 to 200 nm). Among these, the average particle diameter of the powder composed of zinc phthalocyanine halide is 10 to The average aspect ratio of the powder composed of zinc phthalocyanine halide may be, for example, 1.0 to 3.0. A powder having such an average particle diameter and average aspect ratio can be produced, for example, by the method described in International Publication No. 2021 / 220495.

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

[0059] (Catalyst) Another embodiment of the present disclosure is a catalyst (for example, an electrode catalyst) containing 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 excellent catalytic activity when used as a catalyst for the cathode of an oxygen electrolysis device. In particular, the catalyst of this embodiment tends to exhibit excellent catalytic activity when used under basic conditions.

[0060] (Dispersion liquid) 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 or the like. That is, one aspect of the dispersion is an ink composition for forming an electrode catalyst layer.

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

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

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

[0064] When the dispersion contains a solid content other than the composite material (for example, the above binder), the content of the composite material may be 40 to 80% by mass based on the total amount of the solid content in the dispersion. The content of the binder in the dispersion may be 20 to 60% by mass based on the total amount of the solid content in the dispersion. When the dispersion contains a polymer electrolyte, the content of the polymer electrolyte may be 20 to 60% by mass based on the total amount of the solid content in the dispersion. Note that the total amount of the solid content 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 electrolyzer). As for the configuration of the electrode other than the electrode catalyst layer, a conventionally known configuration regarding the cathode of the device can be adopted. The electrode of one embodiment may further include, for example, a gas diffusion layer, a microporous layer, and the like.

[0066] The electrode catalyst layer may be composed only of the composite material, but may contain components other than the composite material according to its use. Examples of the components other than the composite material include binders such as the above-described polymer electrolyte. The ranges of the contents of the composite material, the binder, and the 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, the binder, and the polymer electrolyte in the dispersion of the above embodiment (based on the total amount of solids in the dispersion).

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

[0068] (Electrolyzer) Another embodiment of the present disclosure is an electrolyzer including the electrode of the above embodiment. This electrolyzer is an oxygen electrolyzer and includes the electrode of the above embodiment as an oxygen reduction electrode (cathode). Since the oxygen electrolyzer synthesizes hydrogen peroxide with the decomposition of oxygen, it can also be called a hydrogen peroxide synthesis device. As for the configuration of the battery other than the cathode, a conventionally known configuration regarding the oxygen electrolyzer can be adopted.

Examples

[0069] Hereinafter, the content of the present disclosure will be described in more detail using experimental examples, but the present disclosure is not limited to the following experimental examples.

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

[0071] <Method for Measuring the Average Particle Size> The average particle size (average primary particle size) of the materials used in the experimental examples was calculated from the average value of 40 primary particles constituting the aggregates on the two-dimensional image after ultrasonically dispersing the materials in cyclohexane and then photographing them with a microscope.

[0072] <Method for Measuring the BET Specific Surface Area> The BET specific surface areas of the materials and composite materials used in the experimental examples were measured by the nitrogen adsorption method. The measurement was carried out using a fully automatic specific surface area measuring device Macsorb HM model-1208 (manufactured by Mountech Co., Ltd.) in accordance with the "Method for Measuring Gas Adsorption Amount by the One-Point Method" specified in Annex 2 of Japanese Industrial Standard JIS Z8830-1990.

[0073] <Method for Measuring Conductivity> The conductivities of the materials and composite materials used in the experimental examples were measured using an automatic powder resistance measurement system (MCP-PD600 type manufactured by Nitto Seiko Analytic Co., Ltd.). The automatic powder resistance 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 type manufactured by Nitto Seiko Analytic Co., Ltd.). After charging the carbon material into the low-resistance probe unit, the volume resistivity [Ω·cm] when a load of 12 kN was applied was measured, and the reciprocal thereof was taken as the conductivity [S / cm].

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

[0075] Next, a composite material of Experimental Example 1 was prepared using the above raw material 1 (BrCl-ZnPc(A)) and the above raw material 2 (Carbon ECP). Specifically, first, 20 mg of raw material 1 (BrCl-ZnPc(A)) and 200 mL of dimethyl sulfoxide (DMSO), which is a liquid medium, were added to a 450 mL glass bottle to prepare a mixed solution. Next, the obtained mixed solution was subjected to ultrasonic treatment at 31 kHz for 30 minutes or more using a Benchtop Ultrasonic Cleaner W-113MKII manufactured by Honda Electronics Co., Ltd. Then, the mixed solution after ultrasonic treatment was 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, filtered, washed with ethanol, and vacuum dried. Thereby, a composite material containing a carbon material (carbon black) and brominated and chlorinated zinc phthalocyanine fixed on the surface of the carbon material was obtained.

[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 ratios shown in Table 1.

[0077] <Experimental Example 5> A composite material of Experimental Example 5 was prepared in the same manner as Experimental Example 1, except that C.I. Pigment Green 59 (powder of brominated and chlorinated zinc phthalocyanine, average number of bromine atoms: 8 to 13, average number of chlorine atoms: 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> In a 300 ml flask, 91 g of sulfuryl chloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 109 g of aluminum chloride (manufactured by Kanto Chemical Co., Inc.), 15 g of sodium chloride (manufactured by Tokyo Chemical Industry Co., Ltd.), and 30 g of zinc phthalocyanine (manufactured by DIC Corporation) were charged. Then, the temperature was raised to 130 °C and maintained at 130 °C for 4 hours. The reaction mixture (reaction solution) was taken out into water to precipitate a precipitate, and then the precipitate was 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 Kaiyosui Co., Ltd.), and 35 g of diethylene glycol were charged into a double-arm kneader and kneaded at 80 °C for 18 hours. Then, the obtained mixture was taken out 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 (powder of zinc phthalocyanine having chlorine as a substituent, average number of chlorine atoms: 8 to 13, average particle diameter: 10 to 60 nm, "Cl-ZnPc" in Table 1).

[0079] Except for using the chlorinated zinc phthalocyanine obtained above as Raw Material 1, the composite material of Experimental Example 6 was prepared in the same manner as in Experimental Example 1.

[0080] <Experimental Example 7> Except for using 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 2 / g, conductivity: 30.86 S / cm) as Raw Material 2, the composite material of Experimental Example 7 was prepared in the same manner as in Experimental Example 1.

[0081] <Experimental Example 8> Except for using activated carbon (powder) (trade name, activated carbon manufactured by Kanto Chemical Co., Inc., product number: 01085 - 02, BET specific surface area: 668 m 2 / g, conductivity: 10.14 S / cm) as Raw Material 2, the composite material of Experimental Example 8 was prepared in the same manner as in Experimental Example 1.

[0082] <Experimental Example 9> Except for using zinc 1,2,3,4,8,9,10,11,15,16,17,18,22,23,24,25 - hexadecafluoro - 29H,31H - phthalocyanine (powder of fluorinated zinc phthalocyanine, product code: 444529, average fluorine: 11 - 16, average particle size: 50 - 100 nm, "F - ZnPc" in Table 1) manufactured by Sigma - Aldrich as Raw Material 1, the composite material of Experimental Example 9 was prepared in the same manner as Experimental Example 1.

[0083] <Experimental Example 10> Except for using iron phthalocyanine ( "FePc" in Table 1, iron(II) phthalocyanine, product code: P0774, manufactured by Tokyo Chemical Industry Co., Ltd.) as Raw Material 1, the composite material of Experimental Example 10 was prepared in the same manner as Experimental Example 1.

[0084] <Experimental Example 11> Except for using chlorinated iron phthalocyanine in which all 16 hydrogen atoms are substituted by chlorine atoms ( "Cl - FePc" in Table 1, product number: 097, manufactured by Cosmo Bio Co., Ltd.) as Raw Material 1, the composite material of Experimental Example 11 was prepared in the same manner as Experimental Example 1.

[0085] <Experimental Examples 12 - 15> Except for using tetrahydrofuran (THF), ethyl acetate (AcOEt), diethylene glycol (DEG) or ethanol (EtOH) as the liquid medium for preparing the mixed solution, the composite materials of Experimental Examples 12 - 15 were prepared in the same manner as Experimental Example 1.

[0086] <Evaluation 1: Conductivity> Using an automatic powder resistivity measurement system (MCP-PD600 type manufactured by Nitto Seiko Analytic Co., Ltd.), the conductivity [S / cm] of the composite materials obtained in the above Experimental Examples 1 to 15 and the above carbon ECP was measured. 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 type manufactured by Nitto Seiko Analytic Co., Ltd.). After putting the material into the low-resistance probe unit, the volume resistivity [Ω·cm] when a load of 12 kN was applied was measured, and the reciprocal thereof was taken as the conductivity [S / cm]. The results are shown in Table 1.

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

[0088] First, 4.1 mg of the 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 irradiating with ultrasonic waves for 5 minutes to obtain a dispersion. 4 μL of the dispersion was dropped onto the disk part of a platinum ring GC disk electrode (RRDE) (BAS, product number 012613, outer diameter of the ring part: 7.0 mm, inner diameter of the ring part: 5.0 mm, outer diameter of the disk part: 4.0 mm) and left to stand for about 10 minutes to dry. This was carried out a total of 2 times, and by applying a total of 8 μL of the dispersion, 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 to evaluate the oxygen reduction activity of the measurement catalyst electrode by the three-electrode electrochemical cell method. Specifically, first, nitrogen (N 2) The measurement system was stabilized by cycling in a 0.1 M KOH aqueous solution saturated with [Oxygen] within the range of -0.7 to 0.1 V (vs. Ag / AgCl) at a scanning rate of 100 mV / s. Next, in a 0.1 M KOH aqueous solution saturated with [Oxygen], linear sweep voltammetry (LSV) measurement was performed while rotating the measurement catalyst electrode at 1600 rpm. The LSV measurement was carried out by scanning the range of -0.7 to 0.1 V (vs. Ag / AgCl) from the noble potential to the base potential at 10 mV / s. The potential of the ring electrode was set to 0.2 V (vs. Ag / AgCl), which is a potential capable of sufficiently oxidizing hydrogen peroxide. 2 ) The voltammogram obtained by measurement with an 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),

[0090] the ring current value I Disk , and the reaction start potential E Ring were determined. In the following formula, E onset is the potential based on the Ag / AgCl electrode, E observed was taken as 0.195, and the pH was taken as 13.0. 0 Ag / AgCl E = E RHE + 0.0590pH + E 0 Ag / AgCl observed 2

[0091] Also, in order to confirm the ratio of the two-electron reduction reaction (the reaction generating hydrogen peroxide) among the catalyzed oxygen reduction reactions, based on the following formula (a1), the hydrogen peroxide generation rate (%H 2 O 2 ) was determined. The capture rate N was calculated based on the following formulas (a2) to (a5) using the outer radius r 1 of the disk part of the disk electrode, the inner radius r 2 of the ring part of the ring electrode, and the inner radius r 3 of the ring part of the ring electrode. · %H 2 O 2 (unit: %) = 2 × 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, the potential at which a reduction current of 0.1 mA / cm 2 flows is taken as the reaction start potential, and the disk current value I Disk at 0.4 V (vs. RHE) is 2 -1.5 mA / cm 2 or less, the reaction start potential is 0.5 V or more, and the hydrogen peroxide production rate (%H 2 O Disk ) is 50% or more. When these conditions are met, it is determined that the composite material has sufficient two-electron reduction activity. When the disk current value I 2 at 0.4 V (vs. RHE) is 2 -3.0 mA / cm 2 or less, the reaction start potential is 0.7 V or more, and the hydrogen peroxide production rate (%H

[0093]

Table 1

Claims

1. A carbon material; The carbon material has a structure represented by the following formula (1): 【Chemistry 1】 [X 1 to X 16 in formula (1) each independently represent a hydrogen atom or a halogen atom, provided that at least one of X 1 to X 16 is a halogen atom.] and a halogenated zinc phthalocyanine having a structure represented by The halogenated zinc phthalocyanine has a bromine atom and a chlorine atom as halogen atoms, The halogenated zinc phthalocyanine has an average bromine number of 4 to 16, The average chlorine number of the halogenated zinc phthalocyanine is more than 0 and 11 or less.

2. 2. The composite material according to claim 1, wherein the halogenated zinc phthalocyanine has an average halogen number of 8 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.

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