KR100914991B1 - Platinum group metal particles-distributed carbon or graphite nanofiber and method for producing it - Google Patents

Abstract

The present invention comprises (a) a carbon fiber precursor, (b) a solvent for dissolving the carbon fiber precursor, and (c) 0.1 to 50 parts by weight of a platinum group metal or salt thereof based on 100 parts by weight of the carbon fiber precursor solids. The present invention relates to carbon or graphitized nanofibers in which platinum group metal particles prepared by electrospinning a spinning solution, oxidatively stabilizing, carbonizing and, if necessary, graphitizing, are dispersed.

Carbon or graphitized nanofibers in which platinum group metal particles are dispersed according to the present invention have a large specific surface area and excellent electrical conductivity, and are useful in various industrial fields such as hydrogen detection sensors, hydrogen purifiers, hydrogen reactors, and catalyst layers for fuel cells. Can be used.

Description

Platinum group metal particles-distributed carbon or graphite nanofiber and method for producing it

The present invention relates to carbon or graphitized nanofibers in which platinum group metal particles are dispersed and a method of manufacturing the same.

Carbon materials have been manufactured in various forms, and catalyst graphitization, which makes it difficult to graphitize a carbon material that is difficult to graphitize at low temperatures by mixing and heat-treating an inorganic compound containing most metals or metal elements with a carbon material precursor material. Various preparations have been made by the method.

In the case of activated carbon fiber having high specific surface area and chemical and electrical stability, it is porous by using pores that are formed when metal particles are detached by stabilizing, carbonizing and activating spinning by mixing metal compound or chloride in spinning solution or melt There are also attempts to produce activated carbon fibers. As an example, Korean Patent No. 10-0702156 discloses ultrafine porous carbon fibers and a method of manufacturing the same, and catalyzes the graphite of a metal by electrospinning a halogenated polymer solution containing a metal compound that induces a graphitization reaction at a low temperature. Induced, and a method for producing a porous carbon material as the metal is released. This method has a disadvantage in that the carbonization yield is drastically lowered by using a halogenated polymer material as a starting material, and carbonization (500-1500 ° C.) or graphitization (1500-3000 ° C.) treatment is performed. In order to maintain the fibrous form during the high temperature heat treatment, a stabilization process for converting the thermoplastic structure into a thermosetting structure is essential. However, in the case of halogenated polymer, it is difficult to convert the thermoplastic structure into a thermosetting structure by dehalogenation, and it is difficult to fix the fibrous form due to melting of the fiber by heat treatment because the structural change from thermoplastic to thermosetting is difficult even by thermal stabilization. There is this.

Korean Patent No. 10-0605006 discloses a method for producing activated carbon fibers having a pore structure by removing metals by electrospinning, stabilizing and carbonizing a metal salt that promotes activation such as ZnCl _{2 in a} spinning solution. . In the case of the above methods, a method of obtaining an activation effect as the metal particles are detached by electrospinning and stabilizing and carbonizing a metal or a metal salt in a spinning solution is made.

Carbon particles containing metal particles are most commonly produced by coating metal particles directly on carbon fibers. However, in the case of the coating method, there is a problem in that the metal particles are detached when the metal particles and fibers are weakly bonded, and the coating solution coats the metal particles to reduce the electrical conductivity and the like, and the metal particles are hard to be uniform and highly dispersed. There is a problem.

In order to solve the above problems, the method described in the Republic of Korea Patent Application No. 10-2006-0101929 filed by the inventors of the present invention by dissolving a fiber-forming polymer and silver (Ag) metal salt in a solvent to electrospin the spinning solution, There is a method of carbonizing to produce silver nano-containing carbonized nanofibers. The silver nano-containing carbonized nanofibers by this method are in the form of a nonwoven fabric having a unit fiber diameter of mostly less than 1 μm. The bonding strength between the silver nanoparticles and the carbonized nanofibers is strong, and the silver nanoparticles are mostly reduced during the carbonization process. By precipitation on the fiber surface has the advantage of very good efficiency for the silver nanoparticles.

Palladium (Pd) is a metal with the lowest boiling point and the strongest basic property among platinum group elements. It can dissolve hydrogen atoms up to 600 times its volume, and the absorbed hydrogen reacts with palladium to form PdHx hydrogen compounds. To form. Due to these characteristics, it is one of metals that are being applied to various types of hydrogen gas sensors, hydrogen storage alloys, hydrogen separation devices, hydrogen reactors, and the like.

Therefore, when the carbon or graphitized nanofibers containing the platinum group metal particles are produced by the above-mentioned electrospinning, the specific surface area is large and the electrical conductivity is excellent. Therefore, the hydrogen detection sensor, the hydrogen purifier, the hydrogen reactor, and the fuel cell It is believed that the present invention can be usefully used in various industrial fields such as catalyst layers.

However, when preparing a spinning solution containing platinum group elements, most of the platinum group elements such as palladium are bound to protons (H ⁺ ) in the solution due to the catalysis and basic properties, thereby releasing hydroxide ions (OH ⁻ ), thereby rapidly increasing the viscosity of the solution. It is difficult to progress the spinning smoothly because it causes the above, and also in the case of using the spinning solution containing a platinum group element such as palladium to overcome the above difficulties, after electrospinning, carbonization or graphite It is necessary to adjust the conditions so that the platinum group metal precipitates on the surface of the fiber under the oxidizing condition. However, it is very difficult to control it.

An object of the present invention is to solve the above problems of the prior art, and to provide carbon or graphitized nanofibers in which platinum group metal particles having a large specific surface area to volume and excellent electrical conductivity are dispersed.

Another object of the present invention is to provide a method for producing carbon or graphitized nanofibers in which the platinum group metal particles are dispersed.

In addition, another object of the present invention is to provide a carbon or graphitized nanofibers made of a multi-component by complexing two or more carbon fiber precursors in the production of platinum group-containing carbon or graphitized nanofibers.

The present invention comprises (a) a carbon fiber precursor, (b) a solvent for dissolving the carbon fiber precursor, and (c) 0.1 to 50 parts by weight of a platinum group metal or salt thereof based on 100 parts by weight of the carbon fiber precursor solids. Provided are carbon nanofibers in which platinum group metal particles prepared by electrospinning a spinning solution, oxidatively stabilizing, and carbonizing are dispersed.

The present invention also provides graphitized nanofibers in which platinum group metal particles prepared by graphitizing the carbon nanofibers are dispersed.

In addition, the present invention

A spinning solution comprising (a) a carbon fiber precursor, (b) a solvent for dissolving the carbon fiber precursor, and (c) 0.1 to 50 parts by weight of a platinum group metal or a salt thereof based on 100 parts by weight of the carbon fiber precursor solids. Manufacturing;

Preparing nanofibers by electrospinning the spinning solution prepared above;

Oxidative stabilization of the electrospun nanofibers in air to produce infusible nanofibers; And

It provides a method for producing carbon nanofibers in which platinum group metal particles are dispersed, wherein the oxidatively stabilized infusible nanofibers are carbonized in an inert gas or in a vacuum state.

The present invention also provides a method for producing graphitized nanofibers in which platinum group metal particles are dispersed, further comprising graphitizing the carbonized nanofibers in an inert gas or vacuum state in the method for producing carbonized nanofibers. .

The carbon or graphitized nanofibers in which the platinum group metal particles are dispersed according to the present invention is uniformly dispersed in the platinum group metal particles on the surface of the nanofibers, has a large specific surface area to volume, and has excellent electrical conductivity, such as a hydrogen detection sensor, a hydrogen purifier, It can be usefully used in various industrial fields such as a hydrogen reactor, a catalyst layer for a fuel cell.

1 is a scanning electron micrograph of a palladium-containing nanofiber prepared according to an embodiment of the present invention ((a) x 1K, (b) x 5K, (c) x 30K).

2 is a thermal analysis graph (TGA) of palladium-containing nanofibers prepared according to one embodiment of the present invention.

3 is a scanning electron micrograph of the palladium-containing incompatible nanofibers prepared according to an embodiment of the present invention ((a) x 1K, (b) x 5K, (c) x 30K].

4 is a scanning electron micrograph of palladium-containing carbonized nanofibers prepared according to an embodiment of the present invention ((a) x 1K, (b) x 5K, (c) x 30K).

5 is an X-ray diffraction graph photograph of palladium-containing nanofibers prepared according to an embodiment of the present invention ((a) radiation, (b) stabilization, (c) carbonized fiber).

6 is an XPS diffraction graph photograph of palladium-containing nanofibers prepared according to an embodiment of the present invention [(a) radiation, (b) stabilization, (c) carbonized fiber]

7 is a scanning electron micrograph of a PAN graphitized nanofiber prepared according to a comparative example of the present invention [(a) x 1K, (b) x 5K, (c) x 10K, (d) x 30K]

8 is a scanning electron micrograph of a platinum-containing nanofiber prepared according to an embodiment of the present invention ((a) x 5K, (b) x 10K, (c) x 30K).

9 is a scanning electron micrograph of the platinum-containing infusible nanofibers prepared according to an embodiment of the present invention ((a) x 5K, (b) x 10K, (c) x 30K).

10 is a scanning electron micrograph of a platinum-containing carbonized nanofiber prepared according to an embodiment of the present invention ((a) x 5K, (b) x 30K, (c) x 50K].

11 is a transmission electron micrograph of (a) platinum-containing nanofibers and (b) platinum-infused nanofibers prepared according to an embodiment of the present invention.

12 is a transmission electron micrograph of a platinum-containing carbonized nanofiber prepared according to an embodiment of the present invention ((a) scale bar 1 μm, (b) scale bar 10 nm).

13 is an XPS diffraction graph of platinum-containing nanofibers prepared according to an embodiment of the present invention ((a) radiation, (b) stabilization, (c) carbonized fiber).

14 shows an image of a hydrogen sensor manufactured according to an embodiment of the present invention ((a) substrate type, (b) contact type].

-Name of drawing code-

100: substrate, 200: conductive bonding portion, 300: palladium / platinum-containing carbon fiber,

400: power supply, 500: ammeter, 600: coating material

As the carbon fiber precursor used in the present invention, any fiber-forming polymer may be used without limitation, but PAN (polyacrylonitrile), pitch (Pitch), and cellulose (Cellulose) capable of maintaining a fibrous structure during oxidation stabilization, high temperature carbonization and graphitization , PI (polyimide), PBI (polybenzimidazole) and the like are suitable, one of these may be used alone or in combination of two or more.

As a solvent for dissolving the carbon fiber precursor used in the present invention, N, N-dimethylformamide (DMF), dimethylacetamide (DMAc), tetrahydrofuran (THF), nitric acid, sulfuric acid, DMSO, dioxanone (Dioxanone) etc. can be used 1 type or in mixture of 2 or more types.

The content of the carbon fiber precursor in the solution consisting of the carbon fiber precursor and a solvent for dissolving it may be adjusted in consideration of the viscosity of the spinning solution. It can be included in the range of 5 to 50% by weight based on the total weight of the solution.

Platinum group metal salts used in the present invention include palladium chloride (PdCl ₂ ), palladium ammonium nitrate (Pd (NH ₃ ) ₂ (NO ₃ )), palladium bromide (PdBr ₂ ), palladium oxide hydride (PdOH ₂ O), palladium Sulfate (PdSO ₄ ), palladium literate (Pd (NO ₃ ) ₂ ), palladium acetate acetate ((CH ₃ COCH = C (O−) CH ₃ ) ₃ Pd), palladium chloride (PtCl ₂ , PtCl ₄ ), Platinum bromide (PtBr ₂ ), cyanide platinum (Pt (CN) ₂ ), platinum oxide (PtO ₂ xH ₂ O), platinum sulfide (PtS ₂ ), rhodium bromide hydrate (RhBr ₃ xH ₂ O), rhodium chloride (RhCl ₃ ), rhodium chloride (RhCl ₃ xH ₂ O), rhodium oxide (Rh ₂ O ₃ xH ₂ O), rhodium sulfate (Rh ₂ (SO ₄ ) ₃ ), rhodium oxide dihydrate (RhO ₂ xH ₂ O), Ruthenium Oxide Hydrate (RuO ₂ xH ₂ O), Ruthenium Acetate Acetate [(CH ₃ COCH = C (O-) CH ₃ ) ₃ Ru], Ruthenium Bromide (RuBr ₃ ), Iridium Chloride (IrCl ₃ ), Iridium Acetyl Acetate ((CH ₃ COCH = C (O-) CH ₃ ) ₃ Ir) , Iridium chloride hydrate (IrCl ₄ x H ₂ O), and the like, and may be used alone or in combination of two or more selected from them.

In the present invention, the platinum group metal salt is preferably included in 0.1 to 50 parts by weight based on 100 parts by weight of the carbon fiber precursor solids. If it exceeds 50 parts by weight, the spinning may not proceed smoothly, and even if the spinning proceeds due to high viscosity due to the catalysis of the platinum group metal, microfibers of 1 μm or more are produced. In addition, when contained in less than 0.1 parts by weight, 0.1 parts by weight or more is preferable because the catalyst properties of the platinum group particles cannot be effectively used.

In the present invention, a viscosity modifier may be further included in the spinning solution to suppress a sudden increase in viscosity. The viscosity modifier is preferably included in 0.1 to 20% by weight based on the total weight of the spinning solution, the viscosity of the spinning solution is preferably 50 ~ 50,000 CPS to proceed spinning smoothly. If the content of the viscosity regulator exceeds 20% by weight during the stabilization process, there is a problem that the metal particles do not come to the surface and are fixed to the inside by desorption and reaction of the viscosity regulator, and the stabilization process for converting the thermoplastic into thermosetting is sufficiently performed. You will not have a problem. In addition, when included in less than 0.1% by weight, the viscosity of the spinning solution is sharply increased by the platinum group metal salt occurs a problem that spinning can not proceed smoothly.

When the viscosity of spinning solution exceeds 50,000 CPS, electrospinning becomes difficult, and even if spinning, the thickness of the fiber becomes 3 µm or more. In addition, when the spinning solution has a viscosity of less than 50 CPS, the viscosity is too low. impossible.

As the viscosity modifier used in the present invention, a regulator commonly used for industrial purposes may be used, and glycol distearate, methyl gluceth-20, magnesium aluminum silicate, Stearyl Alcohol, Sodium magnesium silicate, Sodium Chloride, Magnesium Sulfate, Polyglyceryl Methacrylate, Polyacrylic Acid, Japan It can be used individually by 1 type or in mixture of 2 or more types chosen from a wax (Japan Wax), Xanthan Gum, and Carnauba Wax.

Electrospinning in the present invention by connecting the spinning solution prepared above to the electrospinning nozzle using a supply device, by forming a high electric field (high density, 10kV ~ 100kV) using a high voltage generator between the nozzle and the current collector Conduct electrospinning. The magnitude of the electric field is related to the distance between the nozzle and the current collector, and in order to facilitate the electrospinning, a relationship between them is used in combination. In this case, as the electrospinning apparatus to be used, generally used ones may be used, and an electro-blowing method or a centrifugal electrospinning method may be used. Nanofibers prepared by the method as described above is in the form of a nonwoven fabric composed mostly of less than 1㎛ diameter.

In the present invention, the stabilization, carbonization, and graphitization of the electrospun nanofibers can be carried out by applying a method generally used in this field without limitation.

The present invention, (a) a carbon fiber precursor, (b) a solvent for dissolving the carbon fiber precursor, and (c) 100 weight of the carbon fiber precursor solids together with carbon or graphitized nanofibers in which the platinum group metal particles are dispersed It provides nanofibers dispersed with platinum group metal particles produced by electrospinning a spinning solution containing 0.1 to 50 parts by weight of a platinum group metal or a salt thereof based on parts.

The present invention also provides an infusible nanofiber in which platinum group metal particles in which oxidatively stabilized nanofibers in which the platinum group metal particles are dispersed are dispersed.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the scope of the present invention is not limited by the following examples.

Example  1: Preparation and Characterization of Palladium-Containing Nanofibers

Polyacrylonitrile (PAN), a carbon fiber precursor, was mixed in the DMF solvent so that the content was 10% by weight (based on solids) based on the total weight of the PAN-DMF solution and stirred at 60 ° C for 24 hours. After dissolution, the solution was cooled to room temperature to prepare a PAN-DMF solution. 10 parts by weight of palladium chloride (Palladium chloride, PdCl ₂ ) based on 100 parts by weight of PAN solids contained in the PAN-DMF solution were mixed and stirred with the PAN-DMF solution to prepare a spinning solution having a viscosity of 50,000 CPS or less. Electrospinning was performed. Electrospinning was performed at an applied voltage of 25 kV, a distance of 25 cm from the spinneret to the current collector, and a normal temperature condition.

Scanning electron micrographs of palladium-containing nanofibers electrospun under the same conditions as above are shown in FIG. The diameter of the fibers was mostly less than 2 μm.

A graph of thermal analysis in air of the palladium-containing nanofibers electrospun under the same conditions is shown in FIG. 2. In FIG. 2, the weight loss below 300 ° C. may be attributed to the volatilization of the residual solvent and the desorption of chlorine molecules of palladium chloride, and the rapid weight loss near 350 ° C. may be attributed to the intrinsic properties of the PAN nanofibers. .

Example  2: stabilization of palladium containing nanofibers and Carbonization , And properties

Oxidation stabilization was carried out by heating the palladium-containing nanofibers prepared in Example 1 at a temperature of 1 ° C. per minute from normal temperature to 280 ° C. in a hot air electric furnace. In Fig. 3, scanning electron micrographs of oxidatively stabilized palladium-containing incompatible nanofibers in air are shown for each magnification ((a) x 1K, (b) x 5K, (c) x 30K).

The palladium-containing carbon nanofibers were carbonized to 1000 ° C. in an inert gas atmosphere using a tubular electric furnace. 4, the scanning electron micrograph of the palladium containing carbon nanofiber is shown. It can be seen from FIG. 4 that the palladium metal is uniformly spherical on the surface of the carbon fiber. It appears that the deposition of palladium metal began near the melting point of palladium chloride at 678 ~ 680 ℃ and diffused to the surface.

5 shows XRD graphs of palladium-containing nanofibers (a), infusible nanofibers (b), and carbon nanofibers (c). It can be seen from FIG. 5 that the peak due to graphite crystals near 2θ = 25 ° appears broadly from the incompatible fiber, and the peak due to crystals of palladium in the carbonized fiber is strong. This is thought to be the reduction of palladium by carbonization, which is believed to be due to the palladium particles coalescing with the melting and diffusion of the palladium particles into the fiber surface.

6 shows the XPS analysis result. In the case of the fiber (a) it can be seen that the peak due to the chlorine molecule is stabilized and the peak due to the double-chlorine molecule disappeared. It is believed that this indicates that chlorine molecules are detached at low temperatures as in the thermal analysis graph.

In the case of incompatible fiber (b), the peak of O1s due to oxidation reaction with oxygen develops, and it is judged that the structure of PAN fiber is converted from thermoplastic to thermosetting. As the heat treatment proceeds, it is confirmed that nitrogen molecules due to PAN itself decrease, and the peak of palladium metal due to carbonization appears strongly. This seems to have developed due to the carbonization treatment, which simultaneously crystallized as palladium diffused to the surface. Table 1 shows the respective element contents during spinning, stabilization and carbonization.

division Carbon (C,%) Nitrogen (N,%) Oxygen (O,%) Palladium (Pd,%) Chlorine (Cl ₂ ,%) Room 68.84 16.38 6.69 3.27 4.82 stabilize 71.75 12.29 15.10 0.86 - Carbonization 86.03 2.67 9.41 1.89 -

Example 3: Preparation and Characterization of Palladium-Containing Graphitized Nanofibers

Palladium-containing carbonized nanofibers prepared by the methods of Examples 1 and 2 were graphitized to 3000 ° C. in a vacuum state using a graphite electric furnace to prepare palladium-containing graphite nanofibers. As the heat treatment temperature was increased, the palladium particles were larger, and the particles and particles were coalesced from the surface. In particular, in the case of electrical conductivity, the heat treatment temperature was increased as the tendency increased. Table 2 shows 10 parts by weight of palladium chloride (PdCl ₂ ) based on 100 parts by weight of PAN polymer solids and shows the bulk electrical conductivity of the samples subjected to electrospinning, stabilization, carbonization, and graphitization processes. It was measured using the 4-point method and compared and shown.

Comparative example  1: palladium Free  Manufacturing and stabilizing nanofibers, Carbonization , Graphitization  And property checking

Polyacrylonitrile (PAN) is mixed with DMF (dimethylformamide), which is a solvent, so that the content of polyacrylonitrile (PAN) is 10% by weight (based on solids) based on the total weight of the PAN-DMF solution. After cooling, a PAN-DMF spinning solution was prepared, and electrospinning and oxidation stabilization were carried out in the same manner as in Example 1, carbonized using a tube electric furnace, and graphitized in the same manner as in Example 3.

Scanning electron micrographs of the PAN nanofibers graphitized at 2800 ° C. are shown in FIG. 7 for each magnification. Bulk electrical conductivity according to heat treatment of nanofibers is summarized in Table 2. In case of carbonization temperature (~ 1500 ° C), the electrical conductivity of Example 1 (palladium-containing nanofibers) was higher than that of Comparative Example 1 (non-palladium-free nanofibers), but it was performed in the case of graphitization treatment (1500-3000 ° C). Example 1 and Comparative Example 1 showed almost similar values. In the case of carbonization performed at a relatively low temperature, the crystallization of the PAN fiber does not proceed, and the case of Example 1 seems to initially exhibit high electrical conductivity values due to the effect of metal palladium particles. However, at the same time as the graphitization, the effect of palladium particles does not appear to be very high.

Heat treatment temperature (℃) 700 1000 1500 2000 2500 2800 Example 1 Electrical Conductivity (S / ㎠) 15 25 33 44 55 74 Comparative Example 1 Electrical Conductivity (S / ㎠) 5 20 30 45 55 75

Example  4: preparation, stabilization of platinum-containing nanofibers, Carbonization , Graphitization  And property checking

Electrospinning was carried out in the same manner as in Example 1, except that 15 parts by weight of platinum chloride (PtCl ₂ ) was mixed based on 100 parts by weight of PAN solid content.

As a result of the electrospinning, the diameter of the average nanofibers was confirmed to be very uniformly radiated to about 350 nm (FIG. 8). The platinum-containing nanofibers thus prepared were raised by 1 ° C. per minute in air in the same manner as in Example 2, and oxidized and stabilized at 280 ° C. for 1 hour to obtain platinum-containing infusible nanofibers (FIG. 9). The obtained platinum-containing infusible nanofibers were raised by 5 ° C. in an inert atmosphere and carbonized at 1000 ° C. for 1 hour to obtain platinum-containing carbonized nanofibers (FIG. 10). As shown in FIGS. 9 and 10, in the spinning and stabilization, platinum particles did not appear on the surface, but the carbon particles were uniformly distributed on the surface by the carbonization treatment. This seems to be due to the phenomenon as described in Example 2. FIG. 11 shows a transmission electron micrograph of the radiation (a) and the infused platinum-containing nanofibers (b). As shown in Figure 11 it can be seen that the platinum particles do not appear on the inside and the surface of the nanofiber. 12 shows a transmission electron micrograph of the carbonized platinum-containing nanofibers. As shown in FIG. 12 (a), it can be seen that the platinum particles are crystallized, and when carbonized at 1000 ° C., it is confirmed that the graphite crystallites around the platinum are well developed as shown in FIG. 12 (b). Can be. This seems to be due to the partial catalytic graphite by platinum. Particularly, in the case of platinum chloride (PtCl ₂ ), the melting point is around 581 ° C., so it exists in the form of platinum chloride during spinning and stabilization, and platinum crystals are formed as the heat treatment proceeds. In FIG. 13, XPS graphs are shown for spinning (a), stabilization (b), and carbonization (c), and Table 3 is shown for each element content. As shown in FIG. 13, the crystallization of platinum proceeds as the heat treatment temperature increases.

division Carbon (C,%) Nitrogen (N,%) Oxygen (O,%) Platinum (Pt,%) Room 77.01 19.17 2.63 1.19 stabilize 72.57 14.84 11.73 0.86 Carbonization 90.43 4.27 3.89 1.41

Example  5: palladium and platinum containing composites Carbonization  Preparation of Nanofibers

A solution was prepared by mixing PAN and a soluble isotropic pitch in a weight ratio of 5: 5, and dissolving it in a mixed solvent of DMF: THF (weight ratio 5: 5) so that the mixture became 30% by weight based on the total weight of the solution. Thereafter, a mixture of platinum chloride (PtCl ₂ ) and palladium chloride (PdCl ₂ ) in a weight ratio of 5: 5 was mixed in an amount of 10 parts by weight based on 100 parts by weight of the PAN and a soluble isotropic pitch mixture, and then a poly Acrylic acid was added in an amount of 5% by weight based on the total weight of the spinning solution to prepare a spinning solution. At this time, the viscosity of the spinning solution was 1,000 CPS. The spinning solution was electrospun in the same manner as in Example 1, and oxidation stabilization and carbonization were performed in the same manner as in Example 2. The average diameter of the spun fiber was about 800 nm, and the fiber diameter was slightly decreased by oxidative stabilization and carbonization. Using the palladium and platinum-containing composite carbon fiber thus obtained was configured as shown in Figure 14 to produce a hydrogen sensor.

The hydrogen sensor using the platinum group-containing carbon nanofiber of the present invention has a large specific surface area compared to the conventional carbon fiber, a contact combustion method, an optical fiber hydrogen sensor, or a sensor using MEMS. It has a high sensing characteristic.

Claims (14)

A spinning solution comprising (a) a carbon fiber precursor, (b) a solvent for dissolving the carbon fiber precursor, and (c) 0.1 to 50 parts by weight of a platinum group metal or a salt thereof based on 100 parts by weight of the carbon fiber precursor solids. Carbon nanofibers in which platinum group metal particles prepared by electrospinning, oxidative stabilization and carbonization are dispersed. The method according to claim 1, wherein the carbon fiber precursor is a complex of one or two or more selected from the group consisting of polyacrylonitrile (PAN), pitch, cellulose (Cellulose), polyimide (PI), and polybenzimidazole (PBI) Carbon nanofibers, wherein the platinum group metal particles are dispersed. The method of claim 1, wherein the platinum group metal salt is palladium chloride (PdCl ₂ ), palladium ammonium nitrate (Pd (NH ₃ ) ₂ (NO ₃ )), palladium bromide (PdBr ₂ ), palladium oxide hydride (PdOH ₂ O), palladium Sulfate (PdSO ₄ ), palladium literate (Pd (NO ₃ ) ₂ ), palladium acetate acetate ((CH ₃ COCH = C (O−) CH ₃ ) ₃ Pd), palladium chloride (PtCl ₂ , PtCl ₄ ), Platinum bromide (PtBr ₂ ), cyanide platinum (Pt (CN) ₂ ), platinum oxide (PtO ₂ xH ₂ O), platinum sulfide (PtS ₂ ), rhodium bromide hydrate (RhBr ₃ xH ₂ O), rhodium chloride (RhCl ₃ ), rhodium chloride (RhCl ₃ xH ₂ O), rhodium oxide (Rh ₂ O ₃ xH ₂ O), rhodium sulfate (Rh ₂ (SO ₄ ) ₃ ), rhodium oxide dihydrate (RhO ₂ xH ₂ O), Ruthenium Oxide Hydrate (RuO ₂ xH ₂ O), Ruthenium Acetate Acetate [(CH ₃ COCH = C (O-) CH ₃ ) ₃ Ru], Ruthenium Bromide (RuBr ₃ ), Iridium Chloride (IrCl ₃ ), Iridium Acetyl acetate _{((CH 3 COCH = C (} O-) CH 3) 3 Ir), Iridium chloride hydrate (IrCl ₄ xH ₂ O) 1 alone or the platinum group metal particles are dispersed carbon nanofibers according to claim 2 that is mixed with a least one element selected from the group consisting of. The carbon nanofibers with dispersed platinum group metal particles according to claim 1, further comprising 0.1 to 20% by weight of a viscosity modifier based on the total weight of the spinning solution. The carbon nanofibers with dispersed platinum group metal particles according to claim 1, wherein the spinning solution has a viscosity of 50 to 50,000 CPS. Graphitized nanofibers in which platinum group metal particles prepared by graphitizing the carbon nanofibers according to any one of claims 1 to 5 are dispersed. A spinning solution comprising (a) a carbon fiber precursor, (b) a solvent for dissolving the carbon fiber precursor, and (c) 0.1 to 50 parts by weight of a platinum group metal or a salt thereof based on 100 parts by weight of the carbon fiber precursor solids. Manufacturing; Preparing nanofibers by electrospinning the spinning solution prepared above; Oxidative stabilization of the electrospun nanofibers in air to produce infusible nanofibers; And A method for producing carbon nanofibers in which platinum group metal particles are dispersed, comprising carbonizing the oxidatively stabilized infusible nanofibers under an inert gas or vacuum state. The method according to claim 7, wherein the carbon fiber precursor complexes one or two or more selected from the group consisting of polyacrylonitrile (PAN), pitch, cellulose (Cellulose), polyimide (PI), and polybenzimidazole (PBI). Method for producing carbon nanofibers, wherein the platinum group metal particles are dispersed. The method of claim 7, wherein the platinum group metal salt is palladium chloride (PdCl ₂ ), palladium ammonium nitrate (Pd (NH ₃ ) ₂ (NO ₃ )), palladium bromide (PdBr ₂ ), palladium oxide hydride (PdOH ₂ O), palladium Sulfate (PdSO ₄ ), palladium literate (Pd (NO ₃ ) ₂ ), palladium acetate acetate ((CH ₃ COCH = C (O−) CH ₃ ) ₃ Pd), palladium chloride (PtCl ₂ , PtCl ₄ ), Platinum bromide (PtBr ₂ ), cyanide platinum (Pt (CN) ₂ ), platinum oxide (PtO ₂ xH ₂ O), platinum sulfide (PtS ₂ ), rhodium bromide hydrate (RhBr ₃ xH ₂ O), rhodium chloride (RhCl ₃ ), rhodium chloride (RhCl ₃ xH ₂ O), rhodium oxide (Rh ₂ O ₃ xH ₂ O), rhodium sulfate (Rh ₂ (SO ₄ ) ₃ ), rhodium oxide dihydrate (RhO ₂ xH ₂ O), Ruthenium Oxide Hydrate (RuO ₂ xH ₂ O), Ruthenium Acetate Acetate [(CH ₃ COCH = C (O-) CH ₃ ) ₃ Ru], Ruthenium Bromide (RuBr ₃ ), Iridium Chloride (IrCl ₃ ), Iridium Acetyl acetate _{((CH 3 COCH = C (} O-) CH 3) 3 Ir), Iridium chloride hydrate (IrCl ₄ xH ₂ O) group, one or method of producing a platinum group metal particles are dispersed carbon nanofibers to a feature that is mixed with a least one member selected from the consisting of. The method of claim 7, further comprising 0.1 to 20% by weight of a viscosity modifier based on the total weight of the spinning solution. The method of claim 7, wherein the spinning solution has a viscosity of 50 to 50,000 CPS. A method for producing graphitized nanofibers, in which platinum group metal particles are dispersed, further comprising graphitizing the carbonized nanofibers in an inert gas or a vacuum state in the method for producing carbonized nanofibers according to claim 7. . A spinning solution comprising (a) a carbon fiber precursor, (b) a solvent for dissolving the carbon fiber precursor, and (c) 0.1 to 50 parts by weight of a platinum group metal or a salt thereof based on 100 parts by weight of the carbon fiber precursor solids. Nanofibers dispersed with platinum group metal particles produced by electrospinning. An infusible nanofiber in which platinum group metal particles in which oxidatively stabilized nanofibers in which the platinum group metal particles are dispersed are dispersed.