JP2018162177A - Porous carbon material and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of producing a porous carbon material comprising a metal component uniformly supported at a high concentration in a state of microparticles in the pores thereof, which can be used in a variety of applications and is especially useful in a water treatment application.SOLUTION: The porous carbon material which is a baked product of a molding of a kneaded material comprising, in 100 pts.wt. of carbon particles of a mean particle diameter of 10 to 1000 μm, 1 to 15 pts.wt. of iron compound particles and 10 to 80 pts.wt. of a binder which is a carbon precursor, is characterized by having a structure comprising triiron tetraoxide particles of a mean particle diameter of 1 μm or less uniformly dispersed thereinside, a bending strength of 20 MPa or higher, and a specific resistance of 100 μΩ m or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a porous carbon material useful in various fields such as deodorization and decolorization, decomposition of organic compounds and microbial fuel cells.

  Porous carbon materials are lightweight and excellent in heat resistance, corrosion resistance, conductivity, and the like, and have been used for a long time in various application fields such as industrial filters, battery electrodes, adsorbents, and heat insulating materials.

  As a technique for producing the porous carbon material, a method in which coke grains are kneaded with a binder having a high carbonization yield such as coal-based or petroleum-based pitch, and then molded and calcined by carbonization has been known for a long time. This porous carbon material is formed by bonding coke particles with pitch carbides and has a particle-bonded structure.

  For example, in Patent Document 1, as a method for producing a porous carbon material, coke and a binder are blended and kneaded and fired at 900 to 1600 ° C., and the pore diameter has a sharp distribution within a range of 1 to 100 μm. A method for producing a porous carbon material is disclosed.

  However, the porous carbon material obtained by the above method is, for example, an electrode for oxidatively degrading a hardly decomposable organic compound in waste water, or an electrode for a microbial fuel cell that uses microorganisms such as bacteria and fungi for power generation. For more advanced applications such as these, it is necessary to separately carry a catalyst metal and make the surface hydrophilic.

  Therefore, a porous carbon material such as activated carbon is immersed in a metal salt solution using water or an organic solvent (for example, Patent Document 2), or metal is supported on the porous carbon material by a method such as metal coating by an electrolytic method or a gas phase method. To be done.

  However, according to the method of Patent Document 2, it is difficult to carry a large amount of a metal component, and liquid does not enter the closed pores of the porous carbon material, so that uniform distribution of the metal component inside is difficult. In addition, the metal coating technique has a problem that the metal component is unevenly distributed on the surface layer and the surface of the carbon material is covered, so that it is difficult to express the characteristics of the porous carbon material.

  As described above, in the conventional method, there is a problem that it is difficult to carry a metal component in a large amount and uniformly in a porous carbon material with a particle size of submicron to micron order, and it is difficult to mass-produce at low cost. there were.

  Patent Document 3 discloses a method for producing an artificial graphite electrode in which an iron compound having an average particle size of 3 μm or less is added. However, since the iron compound in this document is added to serve as a catalyst for suppressing puffing due to degassing during the production of a graphite electrode and promoting carbonization, the amount is small, Ultimately, it is desorbed during graphitization, and is not intended to support a metal on a carbon material.

JP-A-1-270576 Japanese Patent Laid-Open No. 7-116509 Japanese Patent Publication No. 6-6510

  The present invention provides a method for producing a porous carbon material that can be used in various applications, and in particular, a metal component useful in water treatment applications is supported in a high concentration and uniformly in a porous state in the form of fine particles. is there.

That is, the present invention provides a kneaded molded article comprising 1 to 15 parts by weight of iron compound particles and 10 to 80 parts by weight of a binder serving as a carbon precursor in 100 parts by weight of carbonaceous particles having an average particle diameter of 10 to 1000 μm. A porous product having a structure in which triiron tetroxide having an average particle size of 1 μm or less is uniformly dispersed therein, a bending strength of 20 MPa or more, and a specific resistance of 100 μΩ · m or less. Carbonaceous material.
The porous carbon material preferably has an open porosity of 10 to 20%.

  In the present invention, 100 parts by weight of carbonaceous particles having an average particle diameter of 10 to 1000 μm are blended with 1 to 15 parts by weight of iron compound particles and 10 to 80 parts by weight of a binder serving as a carbon precursor. The molded product is then fired at 800 to 1600 ° C. in a non-oxidizing atmosphere in a firing furnace, and triiron tetraoxide particles having an average particle size of 1 μm or less are uniformly formed inside. In which the bending strength is 20 MPa or more and the specific resistance is 100 μΩ · m or less.

In the production method, the carbonaceous particles are at least one carbonaceous material selected from raw coke and calcined coke obtained from petroleum-based or coal-based heavy oil, and the binder is coal-based or petroleum-based. a binder pitch, it is preferable iron compound particle is ferric oxide (Fe 2 _{O 3).}

According to the present invention, using a raw material that can be stably supplied in a large amount, while maintaining the characteristics of the porous carbon material, the iron particles are made into fine Fe ₃ O ₄ (magnetite, conductive) in a high concentration state in the form of fine particles. And the porous carbon material carry | supported uniformly can be obtained easily.

It is a SEM image of Example 1 (acceleration voltage 5kV 5000 times). 2 is an XRD chart of Example 1. FIG.

Hereinafter, the present invention will be described in detail.
The porous carbon material of the present invention is a fired product of a kneaded molded product containing 1 to 15 parts by weight of iron compound particles and 10 to 80 parts by weight of a binder in 100 parts by weight of carbonaceous powder, and has an average particle diameter of 1 μm. The following triiron tetroxide (Fe ₃ O ₄ ) has a structure uniformly dispersed therein, a bending strength of 20 MPa or more and a specific resistance of 100 μΩ · m or less. Further, the method for producing a porous carbon material of the present invention uses carbonaceous particles pulverized to a specified particle size as an aggregate, and blends binders such as iron compound particles and a binder pitch, and knead molding. Then, this is fired in a non-oxidizing atmosphere to produce the fired product.

As the carbonaceous material used as an aggregate in the present invention, natural graphite or artificial graphite, delayed coke produced from a petroleum-based or coal-based heavy oil by a delayed coking process (raw coke) or delayed coke are used. Carbon materials derived from plants such as hard carbon obtained from calcined coke calcined at 900 to 1600 ° C. in a non-oxidizing atmosphere, resin materials and the like, and charcoal and bamboo charcoal can be used.
Among the above carbonaceous materials, artificial graphite, raw coke or calcined coke is preferable as an aggregate from the viewpoint of electrical conductivity, and raw coke from the viewpoint of ease of kneading and forming with an iron compound or a binder. Or calcined coke is more preferable.

First, prior to blending the raw materials, the carbonaceous material is pulverized and classified so as to obtain carbonaceous particles having a desired particle size (also referred to as aggregate particles).
The pore diameter (median diameter) and porosity of the porous carbon material can be controlled by the particle diameter of the carbonaceous particles, the amount of binder used, the firing temperature, and the like. For example, these numbers increase by increasing the particle size of the aggregate particles. Specifically, regarding the particle size of the carbonaceous particles to be the aggregate, the particle size of all the powders is preferably 5 mm or less, more preferably 3 mm or less, of which 0.1 mm or less fine particles, Preferably it is 10% (by weight) or more, more preferably 20% or more. It is also preferable that the balance between the pore diameter and the porosity and the mechanical strength (bending strength) is improved by excluding particles having an intermediate particle diameter, for example, about 0.5 to 1.0 mm. .
The average particle diameter of the carbonaceous particles is 10 to 1000 μm, preferably 20 to 1000 μm, more preferably 50 to 800 μm. If the average particle diameter of the carbon particles exceeds 1000 μm, the void properties of the resulting porous carbon material will be too coarse, and if the average particle diameter is less than 10 μm, the resulting porous carbon material will be too dense and suitable. Absent. In addition, the average particle diameter as used in this specification is the 50% cumulative diameter (d50) in the volume standard particle diameter measured by the laser scattering / diffraction particle diameter measuring method.

  The binder is not particularly limited as long as it can carbonize itself by a baking treatment in a non-oxidizing atmosphere at 800 ° C. or higher and can bind an aggregate. It is preferable to use a resin material having a residual carbon ratio of 40% or more such as a resin or a polyimide resin, or a binder pitch.

  The binder pitch is a petroleum-based or coal-based pitch used as a binder when producing a graphite electrode for steel making, and examples thereof include binder pitch BP-97 (manufactured by Seachem Co., Ltd.). Binder pitch is more preferable as a binder because it is cheaper than resin-based materials and has good electrical conductivity when carbonized.

  The iron compound used in the production of the porous carbon material of the present invention is not particularly limited as long as it can be decomposed and reduced in the production process of the porous carbon material, but it has aspects such as handling and safety. To iron sulfate, iron acetate, iron citrate, iron hydroxide, or iron oxide is preferable, and ferric oxide is more preferable.

Iron oxide includes triiron tetroxide (Fe ₃ O ₄ ), ferric oxide (Fe ₂ O ₃ ), and the like, all of which can be used for producing the porous carbon material of the present invention. However, from the viewpoint of ease of kneading because the crystal is fine and the particle itself is not strong, it is easy to knead, and it is a bengara for pigment (a red pigment mainly composed of Fe ₂ O ₃ ), scaly oxidation Iron (thin plate particles containing Fe ₂ O ₃ as a main component) is preferable, and bengara is more preferable in terms of purity, powder properties, cost, and the like. The iron compound added to the porous carbon material is reduced to a state where FeO, Fe ₃ O ₄ , Fe, or a mixture of two or more thereof, for example, in Bengala after firing, but preferably improved conductivity Therefore, it is preferable that Fe ₃ O ₄ is reduced so as to be single.

  The iron compound has an average particle size of 100 μm or less, preferably 0.05 to 100 μm, more preferably 0.1 to 50 μm. If the average particle diameter exceeds 100 μm, coarse particles remain after kneading the raw materials, resulting in excessively large iron component particles in the porous carbon material, and it is difficult to obtain desired void properties.

  The mixing ratio of the raw materials is adjusted depending on the kneading conditions and the molding method, but the carbonaceous particles (aggregate) and the binder are in the range of 10 to 80 parts by weight of the binder with respect to 100 parts by weight of the aggregate. To do. For example, when a porous carbon electrode is produced by extrusion molding, the binder pitch is 10 to 80 parts by weight, preferably 20 to 50 parts per 100 parts by weight of the graphitizable carbon particles. If the binder pitch is less than 10 parts by weight, the electrode becomes brittle because the mechanical strength decreases. On the other hand, if the binder pitch exceeds 80 parts by weight, the electrical properties and the porosity are deteriorated. The blending ratio is appropriately adjusted within the above range.

Moreover, an iron compound is mix | blended in 1-15 weight part with respect to 100 weight part of aggregates. The amount is preferably 1 to 15 parts by weight, more preferably 2 to 12 parts by weight. By blending the iron compound together with the aggregate and the binder, the iron component can be uniformly supported at a high concentration throughout the material, and the mechanical strength of the porous carbon material after firing can be improved.
In addition, when the compounding amount of the iron compound is less than 1% by weight, the bending strength does not increase so much and the effect of addition cannot be obtained. On the other hand, when the addition amount exceeds 15 parts by weight, the precipitation of iron components on the surface of the carbon material is also large, and the iron components on the surface are gradually oxidized in the air and red rust is generated.

Next, the carbonaceous particles (aggregate) adjusted so as to have a desired particle size in the pretreatment are mixed with a binder and an iron compound at a predetermined ratio and kneaded. Any kneading method may be used as long as the iron compound can be uniformly dispersed. For example, a binder such as tar or pitch is added to coke particles such as pitch coke and petroleum coke that have been pulverized and classified to have a desired particle size. Examples of methods commonly used in the production of carbon molded products include blending a predetermined amount of pitch and an iron compound, putting this into a kneader such as a kneader, and kneading at a melting temperature of the binder pitch or higher. It is done.
The iron compound is preferably blended and kneaded with the aggregate and the binder in a powder state, rather than being blended in a state of water or an organic solvent solution.

In addition to aggregates, binders, and iron compounds, carbon fiber chopped fiber, magnesium, manganese, and so on, as long as the porosity and mechanical properties of the porous carbon material are not adversely affected during raw material kneading Metal components other than iron such as copper, zinc, or molybdenum may be added as oxide powder.
In addition, about the addition amount of metal components other than an iron compound, it is preferable to mix | blend so that it may become 1-10 weight part with respect to 100 weight part of iron compounds.

  Molding of the kneaded material obtained by kneading is performed at a temperature exhibiting a predetermined plasticity, in addition to extrusion molding from a die having an extrusion port of a predetermined shape, and by cooling the kneaded material to a desired secondary pulverized particle. It may be a mold-in-molding method in which it is put into a mold having a shape and pressed from above, and further, by cold isostatic pressing (CIP) molding in which the secondary pulverized particles are compression-molded with a rubber press in water. It can also be manufactured.

The molded product obtained by the above molding is fired in a non-oxidizing atmosphere in a firing furnace. By this firing, the iron compound is reduced, and Fe ₂ O ₃ is reduced to FeO, Fe ₃ O ₄ , Fe, or a state in which two or more thereof are mixed. Although it varies somewhat depending on the amount and size of the iron compound to be blended and the firing atmosphere, the firing temperature is preferably performed within a temperature range of 800 to 1600 ° C, more preferably fired at 800 to 1300 ° C. 800-1000 degreeC is still more preferable. If graphitization is performed, the iron component is volatilized, so the effect of adding the iron compound particles disappears and the hydrophobicity becomes strong, which is not suitable. On the other hand, if the firing temperature is 1600 ° C. or higher, the iron compound particles are easily fused to become large particles due to melting of the iron compound. Moreover, since carbonization of a binder becomes inadequate when it is 800 degrees C or less, since the electroconductivity of the obtained porous carbon material will fall, it is unpreferable.
Note that the non-oxidizing atmosphere at the time of firing is a reducing atmosphere, an inert gas atmosphere, or the like, and a gas having reducing properties such as carbon monoxide (CO) or an argon / hydrogen mixed gas may be injected. It is preferable to perform firing in a firing furnace together with a reducing agent containing carbon such as coal or coke breeze (coke powder) because Fe ₃ O ₄ is easily obtained.

In the porous carbon material obtained by the production method of the present invention, the iron component is iron tetroxide (Fe ₃ O ₄ ), preferably in an amount of 0.5 wt% or more, and unevenly distributed in the surface layer portion, Highly concentrated and uniformly dispersed and supported up to the inside. Fe ₃ O ₄ is uniformly dispersed as particles having an average particle diameter of 1 μm or less, preferably 0.1 to 0.5 μm, up to the inside of the molded product. If a very brittle fine polycrystal like Bengala is used as the raw material ferric oxide particles, it is finely pulverized and uniformly dispersed and supported during kneading.

  The porous carbon material of the present invention provides a molded product having a specific resistance of 100 μΩm or less and a bending strength of 20 MPa or more, particularly a molded product having an open porosity of 10 to 20%. More preferably, the specific resistance is 75 to 85 μΩm, the bending strength is 25 to 35 MPa, and the open porosity is 15 to 18%. When the specific resistance and bending strength are within the above ranges, sufficient mechanical strength can be ensured even if secondary processing is performed on the molded body by cutting or the like while maintaining the conductivity as the porous carbon material.

In general, the contact angle of water on the graphite surface is around 110 ° and the hydrophobicity is high, but the molded product obtained by the method of the present invention has a relatively hydrophilic surface property with a contact angle of 30 to 90 ° with water. The water absorption is 5 wt% or more, preferably 7 wt% or more (after 24 hours of water immersion) with respect to 100 parts by weight of the porous carbon material.
Since the porous carbon material of the present invention contains conductive Fe ₃ O ₄ particles, it is excellent in conductivity, catalytic activity, etc., and can be used for an electrode or catalyst for electrolysis. In particular, it is suitable for an electrode for performing electrolytic water treatment.

The porous carbon material of the present invention may be activated after firing. The activation treatment is preferably performed by gas activation by contact reaction of raw materials with oxidizing gas (H ₂ O, CO ₂ , O _2, etc.) at high temperature, although the iron compound particles on the surface of the porous carbon material are slightly oxidized For example, a method of performing gas activation by introducing the atmosphere into the furnace immediately after firing can be employed.

  Further, if necessary, the porous carbon material of the present invention may be immersed in a dispersion of a metal having a catalytic function such as platinum, palladium, titanium oxide, etc., and then re-fired to carry it separately.

  EXAMPLES Hereinafter, although the content of this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples.

Example 1
Pitch coke (PC) having a true density of 1.82 g / cm ³ was pulverized, and 2.4 to 1 mm: 40%, 0.3 to 0.075 mm: 35%, 0.074 mm or less: 25% particle size blend (average) 100 parts by weight of pitch coke particles adjusted to have a particle size of 755 μm), 10 parts by weight of Bengala (Toda Color R580, average particle size of 0.19 μm manufactured by Toda Pigment) and a binder pitch (BP) obtained from heavy coal oil : Softening point 97 ° C) 40 parts by weight was added, and the mixture was heated and kneaded at 200 ° C for 20 minutes. This kneaded product was extruded into a cylindrical shape with a size of 20 mmφ × 100 mm. After molding, it was calcined and carbonized in a non-oxidizing atmosphere at 900 ° C. to obtain a target porous carbon material (cylindrical body).

Examples 2-3
A porous carbon material was obtained in the same manner as in Example 1 except that the amount of Bengala was changed to 2 or 5 parts by weight instead of 10 parts by weight.

Comparative Example 1
A porous carbon material was obtained in the same manner as in Example 1 except that Bengala was not blended.

Comparative Example 2
A porous material prepared by the same method as Comparative Example 1 by preparing a 20% aqueous solution of iron sulfate with ferrous sulfate (iron (II) sulfate heptahydrate 99.5%, first grade Wako Pure Chemical Industries, Ltd.) and pure water. The carbon material was immersed and degassed under reduced pressure, and the porous carbon material was impregnated with an aqueous iron sulfate solution. After removing the porous carbon from the aqueous solution, the surface was wiped with a paper waste, and the amount of ferrous sulfate impregnated was calculated from the weight increment of the porous carbon.
After drying at room temperature for one day, it was dried with a dryer at 60 ° C. and then fired again in a non-oxidizing atmosphere at 900 ° C. to obtain an iron-containing porous carbon material. Sulfur was not completely removed, and there was a smell of sulfur. The obtained porous carbon was then washed with water and dried, but the sulfur odor did not disappear.

Comparative Example 3
A porous carbon material was obtained in the same manner as in Example 1 except that the blending amount of Bengala was changed to 10 parts by weight and 20 parts by weight.

Comparative Example 4
A porous carbon material was obtained in the same manner as in Example 1 except that 10 parts by weight of cast iron powder (iron powder # 300, manufactured by Kyowa Junyaku Kogyo Co., Ltd.) was used instead of Bengala. A sample could not be obtained.

  The porous carbon material (cylindrical body) created in Examples and Comparative Examples was subjected to various evaluations by the following methods. Table 1 shows these formulation and results. In the table, the numerical values (lower part) of the aggregate, the binder, and the iron compound are parts by weight.

[Bulk specific gravity]
The diameter and length of the porous carbon material were measured with calipers, and the apparent specific gravity (bulk specific gravity) was determined from the weight of the round bar.

[Resistivity]
The measurement was performed by a four-terminal measurement method using a constant current power supply (multimeter). Two terminals for energization were connected to both ends of the porous carbon material, and further, two terminals for detection were connected to the side surface of the cylinder at intervals of 65 mm, and a current of 2 A was applied to the two terminals for energization at both ends at room temperature. The actual resistance was obtained by measuring the voltage between the two detection terminals on the side surface, and the specific resistance (actual resistance × length / cross-sectional area) was determined from the cross-sectional area of the cylinder and the distance between the terminals.

[Bending strength]
In accordance with the bending strength measurement method of JIS R 7222, using a bending tester (desktop universal testing machine AGS-500A manufactured by SHIMADZU), a porous carbon material is loaded at a constant load rate of 50 N / sec. The bending strength was calculated from the following formula using the following formula: bending strength = 8 × maximum load × distance between fulcrums / (circumference ratio × cylinder diameter).

[Water absorption rate]
The porous carbon material weighed in advance was immersed in pure water at room temperature, taken out after 24 hours, and then allowed to stand at room temperature for 3 minutes. When there was no water dripping and the water was sufficiently cut, the weight was measured and increased. The weight increase rate was defined as the water absorption rate.

[SEM observation, elemental analysis] Porous carbon material was observed with an electric cutter, and the fracture surface was scanned with a scanning electron microscope (SEM S-4700 Hitachi High Technologies). Shape observation by the company) and elemental analysis of the fracture surface by energy dispersive X-ray analysis (EDX EMAX400 by HORIBA).

[Open porosity]
In accordance with the measurement method of the vacuum method of JIS R 1634, the dry weight of the porous carbon material, the weight of the cylinder when immersed in pure water, and the saturated water when it is saturated with vacuum. The weight was measured, and the open porosity was determined from the following formula using the obtained weight.
Open porosity (%) = (saturated water weight−dry weight) / (saturated water weight−in water weight) × 100

[Average porosity]
A porous carbon material is cut in half in the longitudinal direction, and then cut into a semi-cylinder with a height of about 5 mm, and omnidirectional with an X-ray CT device (X-ray transmission inspection device TUX-3200N manufactured by Marstoken Solutions) The three-dimensional stereoscopic image data was acquired by reconstruction processing. The obtained three-dimensional image data is cut into a size of 3 mm x 3 mm x 10 mm (300 x 300 x 1000 voxels) with image processing software, and statistical processing is performed by calculating the diameter at each location of the void with three-dimensional image analysis software. The average porosity was determined.

[Fe content]
The porous carbon material is finely pulverized with a disk mill (average particle size of about 75 μm), the carbon content is burned in an electric furnace, and the remaining ash content is alkali-melted and dissolved with an acid. Using it, the Fe content was measured by ICP (high frequency inductively coupled plasma) emission spectroscopic analysis in which a calibration curve for the Fe peak and Fe content was previously obtained, and the Fe content was determined from the porous carbon material used and the remaining ash content. Asked.

[XRD]
A porous carbon material is finely pulverized with a disk mill (average particle size of about 75 μm) and is applied to an X-ray diffractometer (Rigaku Corporation, RINT-TTRIII, X-ray tube: CuKα, tube current: 300 mA, tube voltage: 50 kV). The iron component was identified.

[Fe elution amount]
In accordance with the JIS K 0102 factory drainage test method, the porous carbon material is pulverized to a particle size of 5 mm or less with a disk mill, water is added so that the weight to volume ratio is 10%, and the mixture is continuously shaken at room temperature for 6 hours. Shake horizontally. After the elution operation, centrifugation is performed at a centrifugal acceleration of 3000 G for 20 minutes, and the obtained sample solution (supernatant) is filtered using a membrane filter having a pore diameter of 1 μm. The filtrate was used to qualify the iron component eluted in water with a high-frequency inductively coupled plasma emission spectrometer (720-ES, manufactured by VARIAN).

While the porous carbon material of the present invention has almost the same specific resistance as that of the porous carbon material to which no iron compound is added in Comparative Example 1 as seen in Examples 1 to 3 in Table 1, the mechanical strength is compared. Since it is superior to Examples 1 and 2, it is possible to easily obtain a porous carbon material having a high degree of freedom in shape workability and containing a large amount of iron.
Further, unlike the solution immersion type of Comparative Example 2, the porous carbon material of the present invention closes the internal pores or is unevenly distributed in the surface layer so that the contained metal component can be seen in the difference in water absorption. Instead, as observed in FIG. 1, the particle diameter is about 100 nm to 500 nm, and the inside is uniformly dispersed at a high concentration. We also examined the crystalline state by the X-ray diffractometer (XRD), as shown in FIG. 2, the iron component contained in the porous carbon material of Example 1-3, it is confirmed as Fe ₃ O _4, Unlike the comparative example 3, Fe ions were not detected in the dissolution test. In FIG. 2 (XRD), a large peak at 20-30 ° is derived from PC carbon, and other than that, it almost coincided with the peak of magnetite / Fe ₃ O ₄ .

The porous carbon material of the present invention includes, for example, materials for deodorizing and decoloring treatment such as waste water, electrode materials for these electrochemical treatments, supporting materials such as enzymes, algae, and bacteria, and microbial fuel cells. It is suitably used as an electrode material.

Claims (4)

  A calcined product of a kneaded molded product containing 1 to 15 parts by weight of iron compound particles and 10 to 80 parts by weight of a binder serving as a carbon precursor in 100 parts by weight of carbonaceous particles having an average particle size of 10 to 1000 μm, A porous carbon material having a structure in which triiron tetroxide having an average particle diameter of 1 μm or less is uniformly dispersed therein, a bending strength of 20 MPa or more, and a specific resistance of 100 μΩ · m or less.   The porous carbon material according to claim 1, which has an open porosity of 10 to 20%.   100 parts by weight of carbonaceous particles having an average particle size of 10 to 1000 μm are blended with 1 to 15 parts by weight of iron compound particles and 10 to 80 parts by weight of a binder serving as a carbon precursor, and kneaded to form a molded product. Next, this molded product is fired at 800 to 1600 ° C. in a non-oxidizing atmosphere in a firing furnace, and has a structure in which triiron tetraoxide particles having an average particle diameter of 1 μm or less are uniformly dispersed inside. And a method for producing a porous carbon material having a bending strength of 20 MPa or more and a specific resistance of 100 μΩ · m or less. The carbonaceous particles are at least one carbonaceous material selected from raw coke and calcined coke obtained from petroleum-based or coal-based heavy oil, and the binder is a coal-based or petroleum-based binder pitch; The method for producing a porous carbon material according to claim 3, wherein the iron compound particles are ferric oxide.

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