KR102636169B1 - Method for manufacturing carbon fiber coating metal catalyst and carbon fiber for manufacturing electrode prduced thereby - Google Patents

Abstract

The present invention includes the steps of producing a precursor fiber containing a carbon fiber precursor and an organic solvent; Impregnating the precursor fiber with a coating solution containing a metal catalyst in the form of a metal ion or a ligand bound to a metal ion; coating the metal catalyst by heating and stretching the precursor fiber impregnated in the coating solution; and heat-treating the precursor fiber coated with the metal catalyst under an inert gas atmosphere. According to the present invention, a metal catalyst in the form of a metal ion or a ligand bound to a metal ion is manufactured by coating the surface of a polymer carbon fiber, thereby producing a carbon fiber that is morphologically uniform and exhibits excellent mechanical and electrochemical properties. can be manufactured.

Description

Method for producing carbon fiber coated with metal catalyst and carbon fiber for electrode production produced thereby

The present invention relates to a method for producing carbon fiber coated with a metal catalyst and to carbon fiber for electrode production produced thereby. Specifically, a metal catalyst in the form of a metal ion or a ligand bound to a metal ion is applied to the surface of a polymer carbon fiber. It relates to a method for manufacturing carbon fibers that are morphologically uniform and have excellent mechanical and electrochemical properties by coating them, and to carbon fibers for electrode production manufactured thereby.

Electrochemical reaction can be said to be a process that utilizes electrical energy and converts it into chemical energy. Chemical reactions (oxidation and reduction reactions) occur through electron transfer between materials, and as they begin to be used as a means of converting and storing energy, there is a revival of eco-friendly energy, including fuel cells, green hydrogen (water electrolysis hydrogen) production, and carbon dioxide reduction. Many attempts to reduce energy are being researched and actually commercialized.

Under this background, conventionally, metal catalysts were used to lower the energy of electrochemical reactions, and platinum was used as the metal. However, platinum catalysts have high efficiency with low overvoltage (meaning the generation of additional applied voltage or dissipated energy compared to the theoretical reaction voltage) and fast reaction speed, but due to the high price range because it is a precious metal and low durability in electrolyte, it gradually dissolves. There was. In addition, despite the high degree of dispersion, there is a problem that the surface area decreases dramatically as the size of single nanoparticles increases due to gradual aggregation over time, which greatly reduces performance.

To overcome this problem, the inventors of the present invention attempted to maintain dispersion through binding between nitrogen and ruthenium nanoparticles by supporting the metal on a polymer containing nitrogen. In addition, it is inevitable that the process will be expensive, and since it is nanoscale, binding to an additional macroscale support must be considered, and MOF (Metal-Organic Framework), perovskite, graphene, and carbon nanotubes have poor intrinsic durability. We aim to develop a method to manufacture special functional carbon fibers that can be mass-produced, have price competitiveness, and can be used semi-permanently, using meter-scale carbon fibers as a support, rather than nano-scale carbon supports, and use them as catalyst electrodes. did.

Meanwhile, the inventors of the present invention have previously studied a method of manufacturing carbon fiber supported with a metal catalyst. More specifically, in order to support the metal catalyst on carbon fiber, the metal catalyst is first mixed with polymer carbon to prepare a spinning solution, and then manufactured into a fiber form through direct dry and wet spinning or wet spinning, resulting in a morphologically uniform and excellent electrical power. It was confirmed that it exhibits chemical properties. However, it was confirmed that these carbon fibers cannot be used for catalytic reactions as the metal particles are evenly distributed inside them, so a relatively large amount of catalyst is wasted. To improve this problem, an additional process of etching the surface of the carbon fiber can be performed through oxygen plasma treatment. However, along with the complexity of the process, the distributed metal particles inside the carbon fiber may cause defects in the fiber structure. As a result, there was a problem in that the carbon fiber was cut during use.

In order to solve this problem, the inventors of the present invention manufactured carbon fibers loaded with metal catalysts, coated them so that the metal catalysts were distributed only on the outer surface of the carbon fibers, and formed the inside of the carbon fibers with polymer carbon to increase mechanical properties. The invention regarding the manufacturing method of carbon fiber and the carbon fiber manufactured thereby for manufacturing electrodes has been completed.

Korean Patent Publication No. 10-2009-0041135

In order to solve the above-described problems, the present invention coats a metal catalyst in the form of a metal ion or a ligand bound to a metal ion on the surface of a polymer carbon fiber to achieve morphologically uniform and excellent mechanical and electrochemical properties. The purpose is to provide a method for producing carbon fiber having a and carbon fiber for electrode production produced thereby.

In order to achieve the above object, the method for producing carbon fiber coated with a metal catalyst according to the present invention includes the steps of producing a precursor fiber containing a carbon fiber precursor and an organic solvent; Impregnating the precursor fiber with a coating solution containing a metal catalyst in the form of a metal ion or a ligand bound to a metal ion; coating the metal catalyst by heating and stretching the precursor fiber impregnated in the coating solution; and heat-treating the precursor fiber coated with the metal catalyst under an inert gas atmosphere.

Here, the carbon fiber precursor may have a molar mass of 100,000 to 750,000 g/mole.

Here, the carbon fiber precursor is polyacrylonitrile (PAN), petroleum/coal hydrocarbon residue pitch, cellulose, polyamic acid, and polyimide (PI). , one type selected from the group consisting of polybenzimidazole (PBI) and polyvinyl alcohol (PVA) may be used alone or in combination of two or more types.

Here, the organic solvent may be one or more selected from the group consisting of DMF (Dimethylformamide), DMAc (Dimethylacetamide), DMSO (Dimethylsulfoxide), NMP (N-Methyl-2-Pyrrolidone), and methanol.

Here, the step of manufacturing the precursor fiber may be performed by dry-jet wet spinning or wet spinning.

Here, the metal catalyst may be one or more selected from the group consisting of metal chloride (X _a Cl _b ), metal acetyl acetonate (X _a (acac) _b ), and ferricyanide compound (X _a CN _b ).

Wherein, There may be more than one species.

Here, the metal catalyst may be coordinated with one or more species selected from the group consisting of phenanthroline, oleate, diethyl triamine, and ethylenediaminetetraacetic acid (EDTA). .

Here, the metal catalyst may be included in an amount of 0.1 to 20 parts by weight based on 100 parts by weight of the carbon fiber precursor.

Here, the step of coating the metal catalyst may be carried out by heating and stretching within the range of 50 to 300°C.

Here, the inert gas may be one or more gases selected from the group consisting of helium, nitrogen, argon, neon, and krypton.

Here, the heat treatment step may carbonize the precursor fiber by heat treatment within the range of 200 to 3000 °C.

Here, the heat treatment step may carbonize the precursor fiber by heat treatment within the range of 1200 to 1800°C.

Here, in the heat treatment step, the precursor fiber may be carbonized by heat treatment by applying a tension of 0.1 to 10.0 MPa per fiber strand.

Meanwhile, the present invention further discloses a metal catalyst-coated carbon fiber manufactured by the method for producing a metal catalyst-coated carbon fiber according to the present invention.

The method for producing carbon fiber coated with a metal catalyst of the present invention according to the above-described method is to coat the surface of a polymer carbon fiber with a metal catalyst in the form of a metal ion or a ligand bound to a metal ion, thereby producing a morphological change. It has the effect of producing carbon fibers that exhibit uniform and excellent mechanical and electrochemical properties.

In addition, the metal catalyst-coated carbon fiber manufactured according to the manufacturing method of the metal catalyst-coated carbon fiber of the present invention not only allows for a large area with low energy, but also stably produces the metal catalyst by unifying the metal catalyst and the carbon fiber. By supporting it, it exhibits stable electrochemical properties even in water for a long period of time, so it can be used as a water electrolysis electrode.

Figure 1 is a flowchart showing each step of the method for producing carbon fiber coated with a metal catalyst of the present invention.
Figure 2 shows a series of processes in the method of manufacturing carbon fiber coated with a metal catalyst of the present invention.
Figure 3 is a schematic diagram showing the manufacturing process of dry and wet spinning and wet spinning of the present invention.
Figure 4 shows the cross-sectional structure of carbon fiber according to an embodiment and a comparative example of the present invention.
Figure 5 shows a TEM image taken of carbon fiber according to an embodiment and a comparative example of the present invention.
Figure 6 shows an SEM image of carbon fiber according to an embodiment and a comparative example of the present invention.
Figure 7 is a graph showing the results of X-ray diffraction (XRD) analysis at each heat treatment temperature of carbon fiber coated with a metal catalyst according to an embodiment of the present invention.
Figure 8 graphically shows the hydrogen evolution reaction (HER) measurement results of carbon fiber according to an embodiment and a comparative example of the present invention.
Figure 9 graphically shows the mass activity conversion results of carbon fibers according to an example and a comparative example of the present invention at the same heat treatment temperature.
Figure 10 is a graph showing the results of X-ray diffraction (XRD) analysis according to tension during the production of carbon fiber coated with a metal catalyst according to an embodiment of the present invention.
Figure 11 shows the change in diameter of carbon fiber according to tension when manufacturing carbon fiber coated with a metal catalyst according to an embodiment of the present invention, the amount of remaining metal catalyst derived from thermogravimetric analysis (TGA), and the results of a hydrogen generation test. is shown in a graph.

The terms used in this application are only used to describe specific examples. Therefore, for example, a singular expression includes a plural expression, unless the context clearly requires it to be singular. In addition, terms such as “include” or “equipped” used in the present application are used to clearly indicate the presence of features, steps, functions, components, or combinations thereof described in the specification, and are not used to indicate other features. It should be noted that it is not used to preliminarily rule out the existence of any elements, steps, functions, components, or combinations thereof.

Meanwhile, unless otherwise defined, all terms used in this specification should be viewed as having the same meaning as generally understood by those skilled in the art to which the present invention pertains. Therefore, unless clearly defined in this specification, specific terms should not be interpreted in an overly idealistic or formal sense.

The inventors of the present invention manufactured carbon fibers supported with metal catalysts in the form of metal ions or in the form of a ligand bound to a metal ion (in the form of a metal precursor bound as a ligand), and coated the carbon fibers so that the metal catalyst was distributed only on the outer surface of the carbon fiber. The present invention was completed by forming the inside of the carbon fiber with polymer carbon, and the degree of metal dissolution, electrochemical properties, and stability of the electrode were confirmed for the carbon fiber of the present invention manufactured accordingly. The present invention is intended to overcome the energy economy and stability problems of existing electrodes by utilizing electrochemical reactions. By carrying and spinning an organic precursor metal containing nitrogen, the dispersion of the metal catalyst is increased, and the agglomeration phenomenon of the catalyst is reduced. It was confirmed that it had the effect of preventing separation from the support.

As a result of research to solve the above-mentioned problems, the present inventors came up with the following invention. The present specification includes the steps of producing a precursor fiber containing a carbon fiber precursor and an organic solvent; Impregnating the precursor fiber with a coating solution containing a metal catalyst in the form of a metal ion or a ligand bound to a metal ion; coating the metal catalyst by heating and stretching the precursor fiber impregnated in the coating solution; and heat-treating the metal catalyst-coated precursor fiber under an inert gas atmosphere.

Figure 1 is a flowchart showing each step of the method for producing carbon fiber coated with a metal catalyst of the present invention. Referring to Figure 1, the method for producing carbon fiber coated with a metal catalyst of the present invention includes the steps of producing a precursor fiber containing a carbon fiber precursor and an organic solvent; Impregnating the precursor fiber with a coating solution containing a metal catalyst in the form of a metal ion or a ligand bound to a metal ion; coating the metal catalyst by heating and stretching the precursor fiber impregnated in the coating solution; It can be seen that the step of heat treating the precursor fiber coated with the metal catalyst under an inert gas atmosphere is carried out in that order.

Figure 2 shows a series of processes in the method of manufacturing carbon fiber coated with a metal catalyst of the present invention. Referring to FIG. 2, the precursor fiber containing a carbon fiber precursor and an organic solvent moves through a roller or guide roller in the form of a filament and is impregnated in a coating solution containing a metal catalyst, and the precursor fiber impregnated in the coating solution moves through the roller. Alternatively, it can be confirmed that a metal catalyst is coated on the outer surface of the precursor fiber while being heated and stretched through a heating roller, and then finally moved through a roller or guide roller to be heat treated in an inert gas atmosphere.

The present invention may include the step of producing a precursor fiber containing a carbon fiber precursor and an organic solvent.

The carbon fiber precursor of the present invention preferably selects a polymer containing a functional group such as nitrogen, carboxyl group (-COO), or catone (-C=O) in order to interact with metal particles and prevent aggregation.

Additionally, the carbon fiber precursor of the present invention preferably has a molar mass of 100,000 to 750,000 g/mole. For example, if the molar mass of the carbon fiber precursor is less than 100,000 g/mole, there is a problem that the mechanical properties are relatively reduced when manufacturing carbon fiber. Conversely, if the molar mass of the carbon fiber precursor is more than 750,000 g/mole, There is a problem in producing a uniform spinning solution due to the agglomeration phenomenon of the precursor polymer.

In addition, the carbon fiber precursor of the present invention preferably uses a fibrous material that can have a mass content of carbon element of 90% or more after the carbonization process. More specifically, the carbon fiber precursor is polyacrylonitrile (PAN), petroleum/coal hydrocarbon residue pitch, cellulose, polyamic acid, and polyimide (PI). ), polybenzimidazole (PBI), and polyvinyl alcohol (PVA). It may be an organic polymer selected from the group consisting of one type alone or a combination of two or more types, as long as it can be used in the industry. It is not limited to this.

The organic solvent of the present invention may be one or more selected from the group consisting of DMF (Dimethylformamide), DMAc (Dimethylacetamide), DMSO (Dimethylsulfoxide), NMP (N-Methyl-2-Pyrrolidone), and methanol, but is limited thereto. That is not the case.

The step of manufacturing a precursor fiber containing a carbon fiber precursor and an organic solvent of the present invention is to prepare a spinning solution by adding and dissolving the carbon fiber precursor in an organic solvent within a temperature range of 25 to 100 ° C, and then dry-wet spinning. -jet wet spinning) or wet spinning (Wet spinning). The spinning solution may contain 5 to 40% by weight of solids based on the total weight of the spinning solution. For example, if the solid content is less than 5% by weight, there is a limit to the fiber-forming ability of the spinning solution. Conversely, if the solid content is more than 40% by weight, there is a limit to producing a uniform spinning solution, so it is preferable to prepare the spinning solution within the above range.

Additionally, it is preferable that the viscosity of the spinning solution is 50 to 1,000 Pa·s. For example, if the viscosity is less than 50 Pa·s, there is a limit to the fiber-forming ability of the spinning solution, and conversely, if the viscosity is more than 1,000 Pa·s, there is a limit to the uniform and stable spinning process.

Conventionally, it was common to manufacture fibers through electrospinning instead of dry or wet spinning. However, in the case of electrospinning, it has a nano-sized thickness and a high surface area, showing excellent activity, but the morphology is not uniform, and the mechanical properties of the fiber are poor, which hinders the durability and large area of the electrode. In addition, it requires a high amount of instantaneous electrical energy consumption and has not yet been commercialized due to limitations in production costs.

However, in the present invention, by manufacturing fibers through dry or wet spinning, it is possible to obtain carbon fibers that not only have excellent mechanical properties and are easy to process even after heat treatment, but also have high catalytic activity and excellent performance.

Figure 3 is a schematic diagram showing the manufacturing process of dry and wet spinning and wet spinning of the present invention. More specifically, Figure 3a shows the manufacturing process of wet and dry spinning of the present invention, and Figure 3b is a schematic diagram showing the manufacturing process of wet spinning of the present invention. Referring to Figure 3, it can be seen that in dry and wet spinning and wet spinning, the process of passing through the first and second coagulation baths through rollers or guide rollers is performed.

In the 1st coagulation bath, a mixed solvent of organic solvent and water is used in a volume ratio of 3:7 to 1:9, and the temperature can be adjusted to within the range of -50 to 100 ℃, 2 In the 2nd coagulation bath, it is desirable to use water as a solvent and set the temperature high to wash away as much of the organic solvent from the fiber as possible. If necessary, the number of baths can be increased to adjust the level of removal of residual solvent inside the fiber. Dry and wet spinning or wet spinning can be produced in the form of fiber by discharging at 1 to 10 m per minute at a temperature of -50 to 100°C in a primary coagulation bath, but this can be adjusted as needed by a person skilled in the art.

After the step of manufacturing the precursor fiber containing the carbon fiber precursor and organic solvent of the present invention, a step of stabilizing the precursor fiber through heat treatment may be additionally performed. In the case of polyacrylonitrile or polyamic acid-based carbon fiber, it is desirable to undergo a stabilization process for cyclization.

More specifically, in the step of stabilizing the precursor fiber through heat treatment, the fiber can be stabilized by applying a tension of 0.1 to 40 MPa per fiber strand and maintaining the temperature within the temperature range of 180 to 350 ° C. for 0.5 to 6 hours. . At this time, the air atmosphere inside the heat treatment may be an inert gas such as nitrogen or argon, air, carbon dioxide mixed gas (CO2 mixed gas), oxygen-nitrogen or oxygen-argon mixed gas. However, if there is no need to separately stabilize the precursor fiber, the step of stabilizing the precursor fiber through heat treatment may be omitted.

The present invention may include the step of impregnating the precursor fiber in a coating solution containing a metal catalyst in the form of a metal ion or a form in which a ligand is bound to a metal ion. Here, the impregnation may refer to a process of infiltrating the precursor fiber into the coating solution through a roller or guide roller.

The metal catalyst of the present invention is preferably in the form of a metal ion or a form in which a ligand is bound to a metal ion, but is not limited thereto.

The metal catalyst of the present invention may be metal nanoparticles with an average particle diameter of 1 to 100 nm. Preferably, the metal catalyst of the present invention is used in the form of a metal ion, and more specifically, metal chloride (X _a Cl _b ), metal acetyl acetonate (X _a (acac) _b ), and ferricyanide compound (X _a CN _b ). It may be one or more types selected from the group consisting of. At this time, a, b, and c are coefficient ratios and can change depending on the type of metal. At this time, the It may be one type selected from the group consisting of palladium.

In addition, the metal catalyst of the present invention includes phenanthroline, oleate, diethyl triamine, and ethylenediaminetetraacetate.

It can also be added by coordinating with one or more types selected from the group consisting of acids (EDTA). At this time, the ligands greatly interact with the polymer chain for metals with high solubility, thereby preventing the metal catalyst from dissolving in water.

The metal catalyst of the present invention may be included in an amount of 0.1 to 20 parts by weight based on 100 parts by weight of the carbon fiber precursor, but this can be adjusted depending on process conditions.

After the step of impregnating the precursor fiber of the present invention in a coating solution containing a metal catalyst in the form of a metal ion or a form in which a ligand is bound to a metal ion, a step of coagulating the precursor fiber impregnated in the coating solution may be additionally performed. You can. Here, the coagulation may be performed through a process of passing through a primary, secondary, etc. coagulation bath through rollers or guide rollers. At this time, the coagulation bath preferably contains an organic solvent such as methanol or ethanol at room temperature, but is not limited thereto.

The present invention may include the step of coating the metal catalyst by heating and stretching the precursor fiber impregnated in the coating solution. Here, the heating stretching may be a process of stretching the precursor fiber impregnated in the coating solution along with heating using primary, secondary rollers, heating rollers, or high temperature steam. By performing the step of coating the metal catalyst by heating and stretching the precursor fiber impregnated in the coating solution, the metal catalyst can be sufficiently supported or coated on the outer surface of the precursor fiber.

The step of coating the metal catalyst by heating and stretching the precursor fiber impregnated with the coating solution of the present invention is preferably performed by heating and stretching within the range of 50 to 300°C. For example, when heat stretching is performed at a temperature of less than 50°C, a problem may occur in which the metal catalyst is not sufficiently coated on the surface of the precursor fiber. Conversely, when heat stretching is performed at a temperature exceeding 300°C, the metal catalyst may be applied to the roller or heating. Problems with sticking to the roller may occur.

The present invention may include heat treating the precursor fiber coated with the metal catalyst under an inert gas atmosphere. The step of heat treating the metal catalyst-coated precursor fiber of the present invention under an inert gas atmosphere is a step of carbonizing the metal catalyst-coated precursor fiber to finally produce a metal catalyst-supported or coated carbon fiber.

In the step of heat treating the precursor fiber coated with the metal catalyst of the present invention under an inert gas atmosphere, as carbonization of the carbon fiber progresses, a graphitic structure is developed, and conductivity is increased.

The inert gas of the present invention may be one or more gases selected from the group consisting of helium, nitrogen, argon, neon, and krypton, but is not limited thereto.

Additionally, the inert gas of the present invention may be supplied within the range of 0.5 to 5 L/min in the heat treatment step.

In addition, the step of heat treating the precursor fiber coated with the metal catalyst of the present invention under an inert gas atmosphere is preferably within the range of 200 to 3000 ° C, and more preferably within the range of 1200 to 1800 ° C. . For example, if the heat treatment temperature is less than 200 ℃, the carbonization of the metal catalyst-coated precursor fiber may not sufficiently occur, which may cause structural instability and reduced conductivity. Conversely, if the heat treatment temperature exceeds 3000 ℃, the metal catalyst may deteriorate. Excessive carbonization of the coated precursor fiber may cause damage to the fiber itself and deterioration of mechanical properties. More preferably, when the heat treatment temperature in the heat treatment step satisfies the range of 1200 to 1800° C., the metal catalyst-coated precursor fiber can be sufficiently carbonized to exhibit excellent electrical conductivity. The heat treatment step can be appropriately adjusted depending on the type of metal catalyst within the heat treatment temperature range.

In addition, the step of heat treating the precursor fiber coated with the metal catalyst of the present invention under an inert gas atmosphere changes the structure of the carbon fiber at intervals of 100°C within the above range because the carbonization point varies depending on the type of metal or metal catalyst. It is advisable to proceed with observation. At this time, the observation method can be used to check the microstructure of the fiber using X-ray diffraction analysis (XRD), and the mechanical properties can be confirmed through a tensile test.

In addition, in the step of heat treating the precursor fiber coated with the metal catalyst of the present invention under an inert gas atmosphere, it is preferable to carbonize the precursor fiber by heat treatment by applying a tension of 0.1 to 10.0 MPa per fiber strand. It is more preferable to carbonize the precursor fiber by heat treatment by applying a tension of 2.5 to 7.5 MPa per strand. For example, if the tension is less than 0.1 MPa in the heat treatment step, carbonization of the precursor fiber coated with the metal catalyst may not occur sufficiently, which may cause structural instability and reduced conductivity. Conversely, if the tension exceeds 10.0 MPa in the heat treatment step, problems may occur. In this case, excessive carbonization of the metal catalyst-coated precursor fiber may cause damage to the fiber itself, and a decrease in mechanical properties and catalytic activity due to ruthenium desorption.

In addition, the step of heat treating the precursor fiber coated with the metal catalyst of the present invention under an inert gas atmosphere is preferably heat treated for 1 to 10 hours under the above temperature and tension conditions, but is not limited thereto.

Meanwhile, the present invention further discloses a metal catalyst-coated carbon fiber manufactured by the method for producing a metal catalyst-coated carbon fiber according to the present invention.

Carbon fiber coated with such a metal catalyst has excellent electrochemical properties, so it can be used to manufacture electrodes required for electrochemical reactions. The electrochemical reactions include oxygen reduction reaction (ORR), hydrogen evolution reaction (HER), oxygen evolution reaction (OER), nitrogen reduction reaction (NRR), and hydrogen oxidation. There are reactions that can cause electron exchange within the electrolyte, such as hydrogen oxidation reaction (HOR), chlorine evolution reaction (CER), and CO2 reduction reaction (CO2 RR). The water electrolysis electrode made of carbon fiber according to the present invention has the advantage of excellent electrode stability regardless of the pH of the electrolyte because it is supported or coated with a metal catalyst.

As mentioned above, the present invention involves manufacturing a precursor fiber containing a carbon fiber precursor and an organic solvent, and then coating a metal catalyst in the form of a metal ion or a ligand bound to the metal ion on the outer surface of the precursor fiber. Accordingly, the stability of the metal catalyst can be improved due to less detachment or elution of the metal. As a result, the carbon fiber coated with the metal catalyst of the present invention has excellent mechanical properties and electrochemical characteristics, so it can be actively used in large-area electrochemical reaction devices including water electrolysis electrodes. It is also economical because it is easy to mass produce. It has quite a beneficial effect.

Hereinafter, what the present specification claims will be described in more detail with reference to the accompanying drawings and examples. However, the drawings, examples, etc. presented in this specification can be modified in various ways by those skilled in the art to have various forms, and the description in this specification does not limit the present invention to a specific disclosed form. It should be viewed as including all equivalents or substitutes included in the spirit and technical scope of the present invention. In addition, the attached drawings are presented to help those skilled in the art understand the present invention more accurately, and may be shown exaggerated or reduced compared to reality.

{Examples and Evaluation}

Example 1. Carbon fiber coated with metal catalyst at a heat treatment temperature of 1200°C

(1) Production of polymer fibers

21.0 g of polyacrylonitrile (PAN) and 141.6 g of DMF were mixed so that the solid concentration was about 12.9 wt%, and the mixture was stirred at 60°C and 50 rpm for 24 hours. This solution was dispersed at 1000 rpm for 5 minutes using a revolving/rotating mixer, defoamed at 2000 rpm for 5 minutes, then vacuum degassed for 15 minutes and used as a spinning stock solution. Solution spinning of the spinning solution was carried out using a dry-jet wet spinning method, and a nozzle with 5 processes and a nozzle diameter of 250 μm was used. The solution discharged at a speed of 7 m/min passes through an air gap of about 10 mm, passes through the 17 m/min roller 1 in the primary coagulation bath, and then through the 17.5 m/min roller 2 and 18.5 m in the secondary coagulation bath. /min was wound on the winder at 21 m/min via roller 3. At this time, the temperature of the first coagulation bath was 10°C, the temperature of the second coagulation bath was 23°C, and methanol was used as a non-solvent in both coagulation baths.

(2) Preparation of coating solution

RuCl ₃ (0.5 g), phenanthroline (1.32 g), and solvent DMF (9.44 g) were mixed and stirred at 50 rpm for 6 hours at room temperature to allow RuCl ₃ to form a coordination bond. Solution 1 was injected into a Polyacro. Nitrile (PAN, 0.5 g) and DMF (34.6 g) were mixed and stirred at 50 rpm at 60°C for 12 hours and slowly added to solution 2, which became transparent, until the solid concentration was about 5 wt%. Stir for an additional 6 hours at 60°C and 50 rpm to ensure uniform dispersion. At this time, the ratio of Ru to polymer is 50 wt%.

(3) Impregnation with coating solution and coating of metal catalyst

The precursor fiber, which is a filament unwound from the unwinder at a speed of 3 m/min by roller 1, was impregnated in a coating solution at room temperature through a guide roller. To ensure that the coating solution is uniformly applied, it passes through three guide rollers and then passes through a coagulation bath filled with methanol at room temperature through 3 m/min roller 2 and 5 m/min roller 3 to form a polymer containing a metal catalyst in the coating solution. The complex was allowed to coagulate. The precursor fiber, which is a filament that has escaped the coagulation bath, is wound by roller 4 and heated through heating roller 1 at 8 m/min, 115°C and heating roller 2 at 24 m/min, 158°C to increase mechanical properties and orient the molecular chain. It has been extended.

(4) Carbonization by heat treatment of carbon fiber

The metal catalyst-coated precursor fiber was heat-treated at 260°C for 5 hours under an air atmosphere (2 L/min) to stabilize the PAN structure. Then, for carbonization, the precursor fiber coated with the metal catalyst was heat treated for 2 hours under a nitrogen gas atmosphere at 1200°C and a tension of 5.0 MPa per fiber was applied to form carbon coated with the metal catalyst of the present invention. Fiber (hereinafter referred to as 'Example 1') was obtained. The carbonized carbon fiber was manufactured into an electrode without any special treatment.

Example 2. Carbon fiber coated with metal catalyst when heat treatment temperature is 1400°C

The metal catalyst of the present invention was prepared in the same manner as in Example 1, except that in the carbon fiber heat treatment step, the metal catalyst-coated precursor fiber was heat-treated at 1400 ° C. instead of 1200 ° C. under a nitrogen gas atmosphere. Coated carbon fiber (hereinafter referred to as 'Example 2') was obtained. The carbonized carbon fiber was manufactured into an electrode without any special treatment.

Example 3. Carbon fiber coated with metal catalyst when heat treatment temperature is 1600°C

The metal catalyst of the present invention was prepared in the same manner as in Example 1, except that in the carbon fiber heat treatment step, the metal catalyst-coated precursor fiber was heat-treated at 1600 ° C. instead of 1200 ° C. under a nitrogen gas atmosphere. Coated carbon fiber (hereinafter referred to as 'Example 3') was obtained. The carbonized carbon fiber was manufactured into an electrode without any special treatment.

Example 4. Carbon fiber coated with metal catalyst when heat treatment temperature is 1700°C

The metal catalyst of the present invention was prepared in the same manner as in Example 1, except that in the carbon fiber heat treatment step, the metal catalyst-coated precursor fiber was heat-treated at 1700 ° C. instead of 1200 ° C. under a nitrogen gas atmosphere. Coated carbon fiber (hereinafter referred to as 'Example 4') was obtained. The carbonized carbon fiber was manufactured into an electrode without any special treatment.

Example 5. Carbon fiber coated with metal catalyst when heat treatment temperature is 1800°C

The metal catalyst of the present invention was prepared in the same manner as in Example 1, except that in the carbon fiber heat treatment step, the metal catalyst-coated precursor fiber was heat-treated at 1800 ° C. instead of 1200 ° C. under a nitrogen gas atmosphere. Coated carbon fiber (hereinafter referred to as 'Example 5') was obtained. The carbonized carbon fiber was manufactured into an electrode without any special treatment.

Example 6. Carbon fiber coated with metal catalyst when heat treatment temperature is 2000°C

The metal catalyst of the present invention was prepared in the same manner as in Example 1, except that in the carbon fiber heat treatment step, the metal catalyst-coated precursor fiber was heat-treated at 2000 ° C. instead of 1200 ° C. under a nitrogen gas atmosphere. Coated carbon fiber (hereinafter referred to as 'Example 6') was obtained. The carbonized carbon fiber was manufactured into an electrode without any special treatment.

Example 7. Carbon fiber coated with metal catalyst when heat treatment temperature is 2200°C

The metal catalyst of the present invention was manufactured in the same manner as in Example 1, except that in the carbon fiber heat treatment step, the metal catalyst-coated precursor fiber was heat-treated at 2200 ° C. instead of 1200 ° C. under a nitrogen gas atmosphere. Coated carbon fiber (hereinafter referred to as 'Example 7') was obtained. The carbonized carbon fiber was manufactured into an electrode without any special treatment.

Example 8. Carbon fiber coated with metal catalyst when heat treatment temperature is 2500°C

The metal catalyst of the present invention was manufactured in the same manner as in Example 1, except that in the carbon fiber heat treatment step, the metal catalyst-coated precursor fiber was heat-treated at 2500 ° C. instead of 1200 ° C. under a nitrogen gas atmosphere. Coated carbon fiber (hereinafter referred to as 'Example 8') was obtained. The carbonized carbon fiber was manufactured into an electrode without any special treatment.

Example 9. Carbon fiber coated with metal catalyst when heat treatment tension is 2.5 MPa and heat treatment temperature is 1200°C

In the carbon fiber heat treatment step, the metal catalyst-coated precursor fiber was heat treated in a nitrogen gas atmosphere by applying a tension of 2.5 MPa per fiber instead of 5.0 MPa, the same as Example 1. By manufacturing using this method, carbon fiber coated with the metal catalyst of the present invention (hereinafter referred to as 'Example 9') was obtained. The carbonized carbon fiber was manufactured into an electrode without any special treatment.

Comparative Example 1. Carbon fiber manufactured by spinning a mixed solution containing a carbon fiber precursor and a metal catalyst and containing a metal catalyst at a heat treatment temperature of 1000°C.

25 g of PAN, 2.566 g of RuCl ₃ , 6.689 g of phenanthroline, and 137.08 g of DMF solvent were mixed so that the solid concentration was about 20 wt%. At this time, 5 parts by weight of ruthenium was used for 100 parts by weight of PAN. At this time, before mixing PAN and ruthenium, they were first mixed in some DMF solvent and added to PAN so that RuCl ₃ and phenanthroline could form a coordination bond. RuCl ₃ and phenanthroline were stirred for 4 hours at room temperature, and after mixing with PAN, they were stirred at 60°C for 6 hours to ensure uniform dispersion. It was spun using a wet spinning method. At this time, the temperature of the first coagulation bath was 10℃, the ratio was DMF:water = 3:7, and the second coagulation bath was set to purified water (DI Water) at 20℃ to form fibers. The organic solvent was sufficiently removed from the solution. The linear speed of the spinning solution was 2 m/min, and the winding speed of the spun fiber was 6 m/min. The thread dried in a vacuum oven was stabilized by heat treatment at 260°C for 5 hours in an air atmosphere (2 L/min) to proceed with cyclization of the structure. The stabilized ruthenium fiber was carbonized by applying a tension of 5.0 MPa at 1000°C for 2 hours under a nitrogen gas atmosphere to obtain a carbon fiber with the metal catalyst uniformly distributed inside and outside (hereinafter referred to as 'Comparative Example 1'). I was able to. The carbonized carbon fiber was manufactured into an electrode without any special treatment.

Comparative Example 2. Carbon fiber prepared by spinning a mixed solution containing a carbon fiber precursor and a metal catalyst and containing a metal catalyst when the heat treatment temperature is 1100 ° C.

Carbon fibers were produced in the same manner as Comparative Example 1, except that in the carbon fiber heat treatment step, the ruthenium fibers were heat-treated at 1100°C instead of 1000°C under a nitrogen gas atmosphere, and the metal catalyst was uniformly distributed inside and outside. (hereinafter referred to as 'Comparative Example 2') was obtained. The carbonized carbon fiber was manufactured into an electrode without any special treatment.

Comparative Example 3. Carbon fiber manufactured by spinning a mixed solution containing a carbon fiber precursor and a metal catalyst and containing a metal catalyst when the heat treatment temperature is 1200 ° C.

Carbon fibers were produced in the same manner as Comparative Example 1, except that in the carbon fiber heat treatment step, the ruthenium fibers were heat treated at 1200°C instead of 1000°C under a nitrogen gas atmosphere, and the metal catalyst was uniformly distributed inside and outside. (hereinafter referred to as 'Comparative Example 3') was obtained. The carbonized carbon fiber was manufactured into an electrode without any special treatment.

Comparative Example 4. Carbon fiber prepared by spinning a mixed solution containing a carbon fiber precursor and a metal catalyst and containing a metal catalyst when the heat treatment temperature is 1300 ° C.

Except that in the carbon fiber heat treatment step, the ruthenium fiber was heat treated at 1300°C instead of 1000°C under a nitrogen gas atmosphere, carbon fiber was manufactured in the same manner as Comparative Example 1, and the metal catalyst was uniformly distributed inside and outside. (hereinafter referred to as 'Comparative Example 4') was obtained. The carbonized carbon fiber was manufactured into an electrode without any special treatment.

Comparative Example 5. Carbon fiber coated with metal catalyst when the tension per fiber strand is 10.0 MPa during heat treatment

In the carbon fiber heat treatment step, the metal catalyst-coated precursor fiber was heat treated in a nitrogen gas atmosphere by applying a tension of 10.0 MPa per fiber instead of 5.0 MPa, the same as Example 1. By manufacturing this method, carbon fiber coated with a metal catalyst (hereinafter referred to as 'Comparative Example 5') was obtained. The carbonized carbon fiber was manufactured into an electrode without any special treatment.

Evaluation 1. Structural analysis of carbon fiber according to heat treatment temperature

The following equipment was used to evaluate the structure of carbon fiber in the manufactured electrode. The following compares and evaluates the properties of the carbon fibers of the above-described examples and comparative examples through structural analysis.

Thermal stability and metal content of the fiber were confirmed using thermogravimetric analysis (TGA). The analysis equipment used was the Q200 model from TA Instrument, USA, and analysis was performed at a speed of 10°C/min. X-ray photoelectron spectroscopy (XPS) was analyzed using an X-ray photoelectron spectrometer (Thermo Fisher K alpha, UK), and It was performed using a high power High-resolution transmission electron microscopy (TEM) was performed using a JEM-2100F (JEOL, Japan) under voltage operation of 200 KeV, and samples were quantified by drop casting the dispersion onto a porous carbon TEM grid. Prepared by drying.

Figure 4 shows the cross-sectional structure of carbon fiber according to an embodiment and a comparative example of the present invention. More specifically, Figure 4a shows the cross-sectional structure of carbon fiber coated with the metal catalyst of Examples 1 to 9, and Figure 4b shows the cross-sectional structure of carbon fiber containing the metal catalyst of Comparative Examples 1 to 4. will be. Referring to Figure 4, in the case of carbon fiber coated with a metal catalyst according to the present invention, it can be seen that the metal catalyst is coated with a uniform thickness on the outer surface of the carbon fiber centered on the circular polymer carbon fiber. In the case of carbon fiber containing a metal catalyst corresponding to the comparative example, the metal catalyst was uniformly contained inside and outside of the circular polymer carbon fiber as it was manufactured into a fiber form by spinning a spinning solution containing a mixture of carbon polymer and metal catalyst. You can check it. In the case of carbon fiber containing a metal catalyst corresponding to this comparative example, the metal particles uniformly distributed inside the fiber cannot be used for catalytic reactions, resulting in a structure in which a relatively large amount of catalyst is wasted. To solve this problem, an additional process of etching the fiber surface through oxygen plasma treatment is required. Additionally, in the case of carbon fiber containing a metal catalyst corresponding to the comparative example, metal particles distributed inside the fiber may act as defects in the fiber structure, causing the fiber to break during use as an electrode.

Figure 5 shows a TEM image taken of carbon fiber according to an embodiment and a comparative example of the present invention. More specifically, Figure 5a shows a TEM image of a carbon fiber coated with a metal catalyst according to an embodiment of the present invention at a specific temperature, and Figure 5b shows a TEM image of a metal catalyst according to a comparative example of the present invention at a specific temperature. This is a TEM image taken of carbon fiber containing a catalyst. Referring to Figure 5, in the case of carbon fiber coated with a metal catalyst according to an embodiment of the present invention, ruthenium, a metal catalyst, is actually coated with a uniform thickness on the outer surface of the carbon fiber centered on the polymer carbon fiber. On the other hand, in the case of carbon fiber containing a metal catalyst according to a comparative example of the present invention, it can be confirmed that the metal catalyst is uniformly contained inside and outside the polymer carbon fiber.

Figure 6 shows an SEM image of carbon fiber according to an embodiment and a comparative example of the present invention. More specifically, Figure 6a shows an SEM image of a carbon fiber coated with a metal catalyst according to an embodiment of the present invention at 1400°C, and Figure 6b shows a metal catalyst according to a comparative example of the present invention at 1400°C. This is an SEM image of a carbon fiber containing a catalyst. Referring to FIG. 6, in the case of carbon fiber containing a metal catalyst according to a comparison of the present invention, agglomeration of ruthenium particles, which is a metal catalyst, occurs at 1400°C, damaging the internal structure of the carbon fiber, resulting in the carbon fiber breaking. On the other hand, in the case of carbon fiber coated with a metal catalyst according to an embodiment of the present invention, ruthenium particles, which are a metal catalyst, are distributed on the outer surface of the carbon fiber, so even at 1400 ° C, ruthenium particles coagulate and coagulate inside the carbon fiber. It can be confirmed that the fiber structure is stably maintained without cracks in the carbon fiber.

Figure 7 is a graph showing the results of X-ray diffraction (XRD) analysis at each heat treatment temperature of carbon fiber coated with a metal catalyst according to an embodiment of the present invention. Referring to Figure 7, it can be observed that as the heat treatment temperature increases, the graphitic structure develops sharply around 26 degrees, and ruthenium crystals develop when the heat treatment temperature is in the range of 1400 to 1800 degrees Celsius. You can check that. In addition, when the heat treatment temperature is 2000 ℃, the ruthenium crystals begin to collapse again. This is because the melting point of ruthenium is about 2300 ℃, so it can be expected that the crystallinity will collapse as it approaches the melting point.

Evaluation 2. Electrochemical reaction measurement and analysis according to heat treatment temperature

Electrochemical reaction measurements were performed in a standard three-electrode cell with a computer connected to a potentialstat (1470E, Solartron, UK). A carbon rod was used as a counter electrode, and an Ag/AgCl electrode immersed in a saturated KCl solution was used as a reference electrode. Two methods were used for the catalyst electrode part. One method was to measure the fiber as it was by contacting it with a copper tape, and the other was to make a dispersion in powder form and place 4 μg of metal catalyst at a time in the form of a film on a glassy carbon (GC) electrode. A measurement method was used. The concentration of the dispersion was 5 g/L, and the solvent used was a mixture containing 20 μL of Nafion (5%) per 1 mL of ethanol. If the carbon fiber according to the comparative example of the present invention is not well powdered or dispersed well, the dispersibility is measured by increasing the dispersibility by O2 plasma treatment (200 W, 5 min). For reliable evaluation, the hydrogen generation reaction was evaluated after nitrogen was injected into the electrolyte for 30 minutes, and 0.5 M H2SO4 and 1.0 M KOH electrolytes were used to evaluate performance in various ranges (pH 0.3 to 14). In addition, for comparative performance, data reliability was improved by using a commercial catalyst (Pt/C, Sigma Aldrich) with 20% platinum supported on carbon.

Table 1 below shows the measured change in metal catalyst and electrical conductivity according to the heat treatment temperature of carbon fiber coated with a metal catalyst according to an embodiment of the present invention. Here, the amount of ruthenium (Ru), a metal catalyst, remaining in each heat treatment temperature section was investigated through thermogravimetric analysis (TGA).

division - Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Heat treatment temperature (℃) 260 1200 1400 1600 1700 1800 2000 2200 2500 Ru amount (wt.%) 1.64 3.75 4.96 5.21 5.00 4.12 3.07 2.88 2.72 Electrical conductivity (S/cm) - 132.81 147.86 170.99 186.62 192.33 231.22 239.77 257.07

Referring to Table 1, it can be seen that in the case of carbon fiber coated with the metal catalyst of the present invention, the amount of ruthenium (Ru) gradually increases as the heat treatment temperature increases, and then gradually decreases around 1700°C. This is because ruthenium particles gradually grew on the outer surface of the carbon fiber during heat treatment and detachment occurred as the diameter of the fiber decreased. Therefore, from the above experimental results, it can be inferred that the maximum amount of ruthenium, the metal catalyst of the carbon fiber coated with the metal catalyst of the present invention, was exposed at 1700°C. Meanwhile, the electrical conductivity of the carbon fiber coated with the metal catalyst of the present invention continues to increase as the heat treatment temperature increases. This is because the crystal structure of carbon inside the fiber develops, making electron transfer easier. It is generally known that when using carbon fiber as an electrode, it is desirable for the electrical conductivity to be 150 to 200 S/cm.

Figure 8 graphically shows the hydrogen evolution reaction (HER) measurement results of carbon fiber according to an embodiment and a comparative example of the present invention. More specifically, Figure 8a graphically shows the results of measuring hydrogen evolution at 20 mA cm ^-2 of carbon fiber coated with a metal catalyst according to an embodiment of the present invention, and Figure 8b is a comparative example of the present invention. This is a graph showing the results of measuring hydrogen generation at 20 mA cm ^-2 of carbon fiber containing a metal catalyst according to . Referring to FIG. 8, in the case of carbon fiber containing a metal catalyst according to one embodiment of the present invention, an overvoltage of 55 to 70 mV is shown at each heat treatment temperature, whereas the carbon fiber coated with a metal catalyst according to an embodiment of the present invention shows an overvoltage of 55 to 70 mV at each heat treatment temperature. In the case of carbon fiber, it can be seen that the overvoltage ranges from 70 to 90 mV depending on the heat treatment temperature (the lowest overvoltage is 89 mV when the heat treatment temperature is 1700°C). That is, it can be seen that in the case of carbon fiber coated with a metal catalyst according to an embodiment of the present invention, hydrogen generation progresses stably and shows excellent performance.

Figure 9 graphically shows the mass activity conversion results of carbon fibers according to an example and a comparative example of the present invention at the same heat treatment temperature. Here, mass activity is a current curve calculated based on catalyst mass and is an indicator that can compare electrochemical performance per catalyst usage. Referring to FIG. 9, when the heat treatment temperature is 1200°C, the carbon fiber coated with the metal catalyst according to an embodiment of the present invention has a higher temperature on the outer surface of the fiber than the carbon fiber containing the metal catalyst according to a comparative example of the present invention. As the ruthenium particles are intensively distributed, the use of unnecessary metal catalysts can be reduced, and it can be confirmed that excellent electrochemical performance is achieved with a relatively small amount.

Evaluation 3. Measurement and analysis of carbon fiber performance according to tension in the heat treatment stage

Figure 10 is a graph showing the results of X-ray diffraction (XRD) analysis according to tension during the production of carbon fiber coated with a metal catalyst according to an embodiment of the present invention. Referring to Figure 10, it can be seen that as the magnitude of tension applied during the heat treatment step in the carbon fiber manufacturing method of the present invention increases, the development rate of the ruthenium metal and fiber structure increases. In addition, in the method for producing carbon fiber of the present invention, ruthenium crystals begin to develop when the tension applied during heat treatment is 2.5 MPa per fiber strand (Example 9), and the tension applied during heat treatment is 5.0 MPa per fiber strand. It can be seen that ruthenium crystals develop rapidly in (Example 1).

Meanwhile, Figure 11 shows the change in diameter of the carbon fiber according to tension, the amount of remaining metal catalyst, and hydrogen generation derived from thermogravimetric analysis (TGA) when manufacturing carbon fiber coated with a metal catalyst according to an embodiment of the present invention. The test results are shown graphically. More specifically, Figure 11a shows the diameter change of the carbon fiber according to tension during the production of carbon fiber coated with the metal catalyst of Examples 1, 9, and Comparative Example 5, and the residual metal catalyst derived from thermogravimetric analysis (TGA). The amount is shown graphically, and Figure 11b graphically shows the results of hydrogen generation according to tension during the production of carbon fibers coated with metal catalysts of Examples 1, 9, and Comparative Example 5.

Referring to Figure 11a, when the tension applied during the heat treatment step in the carbon fiber production method of the present invention is 2.5 MPa (Example 9), the diameter of the carbon fiber of the present invention is about 10.0 ㎛, and the amount of remaining ruthenium is ~7. %, and when the tension applied during the heat treatment step is 5.0 MPa (Example 1), the diameter of the carbon fiber of the present invention is about 9.9 ㎛, and the amount of ruthenium remaining is ~4%, while the tension applied during the heat treatment step is ∼4%. When the tension is 10.0 MPa (Comparative Example 5), the diameter of the carbon fiber is about 8.7 ㎛, and the amount of ruthenium remaining is ~2%. It can be seen that the loss of ruthenium distributed on the surface increases due to the decrease in diameter.

In addition, referring to Figure 11b, the activity of the metal catalyst is highest when the tension applied during the heat treatment step in the carbon fiber manufacturing method of the present invention is 5.0 MPa (Example 1), which means that ruthenium crystals are strongly formed under the tension condition. This can be seen as being due to the large amount exposed to the surface. On the other hand, when the tension applied during the heat treatment step is 2.5 MPa (Example 9), the activity of the metal catalyst is relatively low because ruthenium crystals are formed relatively weakly, and the tension applied during the heat treatment step is 10.0 MPa (Comparative Example In case 5), a large amount of ruthenium is lost, which can be seen as lowering the activity of the metal catalyst.

Considering the results of Figures 10 and 11, as the amount of tension applied during the heat treatment step in the carbon fiber manufacturing method increases, the speed of development of the fiber structure increases and the amount of loss of the metal catalyst also increases, making it the optimal catalyst. It can be seen that in order to select activation conditions, not only the heat treatment temperature but also the magnitude of the applied tension must be considered.

In addition, from the above experimental results, in the method for producing carbon fiber coated with a metal catalyst of the present invention, the heat treatment step is to carbonize the precursor fiber by heat treatment by applying tension of 0.1 to 10.0 MPa per fiber strand. It can be seen that it is preferable to carbonize the precursor fiber by heat treatment by applying a tension of 2.5 to 7.5 MPa per fiber strand.

The method for producing carbon fiber coated with a metal catalyst of the present invention according to the above-described method is to coat the surface of a polymer carbon fiber with a metal catalyst in the form of a metal ion or a ligand bound to a metal ion, thereby producing a morphological change. It has the effect of producing carbon fibers that exhibit uniform and excellent mechanical and electrochemical properties.

In addition, the metal catalyst-coated carbon fiber manufactured according to the manufacturing method of the metal catalyst-coated carbon fiber of the present invention not only allows for a large area with low energy, but also stably produces the metal catalyst by unifying the metal catalyst and the carbon fiber. By supporting it, it exhibits stable electrochemical properties even in water for a long period of time, so it can be used as a water electrolysis electrode.

The above description is merely an illustrative explanation of the technical idea of the present invention, and various modifications and variations will be possible to those skilled in the art without departing from the essential characteristics of the present invention.

Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but are for illustrative purposes, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted in accordance with the claims below, and all technical ideas within the equivalent scope should be construed as being included in the scope of rights of the present invention.

Claims (15)

Manufacturing a precursor fiber containing a carbon fiber precursor and an organic solvent by dry-jet wet spinning or wet spinning;
Impregnating the precursor fiber with a coating solution containing a metal catalyst in the form of a metal ion or a ligand bound to a metal ion;
coating the metal catalyst by heating and stretching the precursor fiber impregnated in the coating solution; and
Comprising the step of heat treating the precursor fiber coated with the metal catalyst under an inert gas atmosphere,
The heat treatment step is characterized in that applying a tension of 2.5 to 7.5 MPa per fiber strand and carbonizing the precursor fiber by heat treatment within the range of 1200 to 1800 ° C. A method of producing carbon fiber coated with a metal catalyst.
According to paragraph 1,
A method for producing carbon fiber coated with a metal catalyst, characterized in that the carbon fiber precursor has a molar mass of 100,000 to 750,000 g/mole.
According to paragraph 1,
The carbon fiber precursor is polyacrylonitrile (PAN), petroleum/coal hydrocarbon residue pitch, cellulose, polyamic acid, polyimide (PI), and polyimide. A method for producing carbon fiber coated with a metal catalyst, characterized in that one type selected from the group consisting of polybenzimidazole (PBI) and polyvinyl alcohol (PVA) alone or in combination of two or more types.
According to paragraph 1,
The organic solvent is a metal catalyst, characterized in that at least one selected from the group consisting of DMF (Dimethylformamide), DMAc (Dimethylacetamide), DMSO (Dimethylsulfoxide), NMP (N-Methyl-2-Pyrrolidone), and methanol. Method for manufacturing provisionally coated carbon fiber.
According to paragraph 1,
The metal catalyst is characterized in that it is at least one selected from the group consisting of metal chloride (X _a Cl _b ), metal acetyl acetonate (X _a (acac) _b ), and ferricyanide compound (X _a CN _b ). Method for manufacturing catalyst-coated carbon fiber.
According to clause 5,
Wherein A method for producing carbon fiber coated with a metal catalyst, characterized in that.
According to paragraph 1,
The metal catalyst is characterized in that it is coordinated with at least one selected from the group consisting of phenanthroline, oleate, diethyl triamine, and ethylenediaminetetraacetic acid (EDTA). , Method for manufacturing carbon fiber coated with metal catalyst.
According to paragraph 1,
A method of producing a carbon fiber coated with a metal catalyst, characterized in that the metal catalyst is included in an amount of 0.1 to 20 parts by weight based on 100 parts by weight of the carbon fiber precursor.
According to paragraph 1,
A method of manufacturing carbon fiber coated with a metal catalyst, characterized in that the step of coating the metal catalyst is heated and stretched within the range of 50 to 300 ° C.
According to paragraph 1,
A method for producing carbon fiber coated with a metal catalyst, wherein the inert gas is one or more gases selected from the group consisting of helium, nitrogen, argon, neon, and krypton.
Carbon fiber coated with a metal catalyst, manufactured according to the manufacturing method of any one of claims 1 to 10. delete delete delete delete

Images