KR100846477B1 - Carbon-metal composite material and process for preparing the same - Google Patents

Abstract

Carbon-metal composites and methods of making the same are disclosed. More specifically, a carbon-metal composite material having improved conductivity, specific surface area and regularity and easy control of particle shape and a method of manufacturing the same are disclosed.

The present invention includes carbon and metal, and 8 mΩ / sq. Under pressure conditions of 100 Kg _f / cm ² . Provided is a carbon-metal composite material having a sheet resistance of less than 30 m ² / g and having an X-ray diffraction pattern having at least one peak at a d-spacing of 6 nm or more, and a method of manufacturing the same.

Description

Carbon-metal composite material and process for preparing the same

1 is a view showing the results of X-ray diffraction analysis of the carbon-nickel composite material prepared in Example 1 of the present invention.

2 is a view showing an SEM photograph of the coordination polymer prepared in Example 1 of the present invention.

3 is a view showing an SEM image of the carbon-nickel composite material prepared in Example 1 of the present invention.

4 is a view showing the results of X-ray diffraction analysis of the carbon-nickel composite prepared in Example 2 of the present invention.

5 is a view showing an SEM photograph of the coordination polymer prepared in Example 2 of the present invention.

6 is a view showing an SEM image of the carbon-nickel composite material prepared in Example 2 of the present invention.

7 is a view showing an SEM image of the coordination polymer prepared in Example 3 of the present invention.

8 is a view showing an SEM image of the carbon-nickel composite material prepared in Example 3 of the present invention.

9 is a view showing an SEM image (X10.0k) of the coordination polymer prepared in Example 7 of the present invention.

FIG. 10 is an enlarged SEM photograph (X30.0k) of the coordination polymer prepared in Example 7 of the present invention. FIG.

FIG. 11 is a SEM photograph (X 10.0k) of the carbon-silver composite prepared in Example 7 of the present invention. FIG.

12 is an enlarged SEM photograph (X 30.0k) of the carbon-silver composite material prepared in Example 7 of the present invention.

13 shows a TEM photograph of the carbon-nickel composite obtained in Example 1 according to the present invention.

Figure 14 shows an enlarged TEM picture of the carbon-nickel composite material obtained in Example 1 according to the present invention.

15 shows the results of X-ray diffraction analysis of Examples 1, 4, 5 and 6 according to the present invention.

Figure 16 shows the results of thermogravimetric analysis of the coordination polymer of Example 1 according to the present invention.

17 shows the results of thermogravimetric analysis on the carbon-nickel composites obtained in Examples 1, 4, 5 and 6 according to the present invention.

18 is a view showing the results of X-ray diffraction analysis of the coordination polymer prepared in Example 7 of the present invention.

19 shows standard reduction potentials of various metals.

20 is a schematic diagram showing a schematic structure of a fuel cell.

The present invention relates to a carbon-metal composite material and a method for manufacturing the same, and more particularly, to a carbon-metal composite material having improved conductivity, specific surface area and regularity, and easy to control a particle shape, and a method for manufacturing the same.

Conventional conductive carbon materials have been mainly used for the purpose of improving the efficiency by reducing the internal resistance of various energy devices, for example, a variety of uses, such as a conductive material or active material of a battery, a carrier of a catalyst for a fuel cell, an electrode material of a supercapacitor, etc. Have

Various studies and attempts have been made to enhance the physical properties of the conductive carbon material and to improve conductivity. Examples of the conductive carbon materials include US Pat. Nos. 4,263,376, 6,649,265, 6,780,350, and 5,783,139.

US Patent No. 4,263, 376 describes an example in which metal particles are attached to the surface of carbon particles and used as a fuel cell catalyst, but the metal particles are only present on the surface of the carbon particles, and are not related to the substantial increase in conductivity of the carbon particles. The improvement of specific surface area was still insufficient, depending on the shape of the carbon particles whose composite particle shape was the base material.

US Patent No. 6,649,265 describes an example of attempting to improve conductivity by filling pores of a material obtained by press-molding carbon particles with a metal, but the contact between the metal and carbon is only partially made and there are still pores that are not filled with metal. It was difficult to expect to improve the conductivity by the addition of metal, and similarly, it was necessary to improve the specific surface area because the composite particle shape was only difficult to control the shape depending on the shape of the carbon particle as the base material. Alternatively, an example is described in which conductivity is improved by spraying a solution in which a carbon precursor and a metal precursor are dissolved in an aerosol state and thermally dispersing carbon and metal in a relatively uniform manner, but only a particle shape close to a sphere is realized due to the characteristics of the aerosol method. Possible but improved specific surface area There was a problem that the production of particles having a variety of shapes for the difficulty.

The U.S. Patent No. 5,783,139 discloses a ceramic fiber obtained through pyrolysis of an organometallic compound dispersed in an organic polymer, but has a problem in that a composite material having a nonuniform composition is obtained.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide a carbon-metal composite material having improved conductivity, specific surface area, regularity, and easy shape control.

Another object of the present invention is to provide a method for producing the carbon-metal composite material.

Another object of the present invention is to provide a catalyst employing the carbon-metal composite material and a fuel cell including the catalyst.

The present invention to achieve the above technical problem,

Carbon and metals,

8 mΩ / sq. Under pressure conditions of 100 kg _f / cm ² . Provided is a carbon-metal composite material having the following sheet resistance.

In one embodiment according to the invention, the specific surface area of the carbon-metal composite is at least 30 m ² / g.

In one embodiment according to the invention, the carbon-metal composite exhibits an X-ray diffraction pattern having at least one peak at d-spacings of 6 nm or more.

In order to achieve the above another technical problem, the present invention provides a method for producing a carbon-metal composite material, characterized in that the heat treatment powder containing a coordination polymer.

As the coordination polymer, a compound having a unit structure of Formula 1 may be used:

<Formula 1>

M _x L _y S _z

Wherein M represents at least one metal selected from the group consisting of transition metals, groups 13, 14, 15, lanthanide metals and actin metals;

L represents a multidentate ligand that simultaneously forms an ionic or covalent bond with two or more metal (M) ions;

S represents a single site ligand which forms an ionic or covalent bond with one metal (M) ion;

When x is the number of functional groups bondable with the metal (M) ions included in L, x, y, and z are yd + z ≦ 6x, x ≧ 1, y ≧ 1, and y + z ≧ 1. An integer that satisfies the relational expression of.

The present invention to achieve the above another technical problem,

Provided are a catalyst comprising, for example, a carbon-metal composite material according to the present invention as a carrier, and a fuel cell comprising the catalyst.

Hereinafter, the present invention will be described in more detail.

The carbon-metal composite according to the present invention is a material in which metal particles are composited together with carbon, and 8 mΩ / sq. Under a pressure condition of 100 kg _f / cm ² . An X-ray diffraction pattern having the following sheet resistance, exhibiting a specific surface area of 30 m ² / g or more as measured by the BET method, and having at least one peak at a d-spacing of 6 nm or more.

These carbon-metal composites according to the present invention can be produced by a method of heat-treating a powder containing a coordination polymer compound. The carbon-metal composite material has a highly regular structure and has excellent electrical conductivity and high specific surface area by forming a network structure in which the coordination polymer compound is a metal structure interconnected via a multidentate ligand.

The coordination polymer is a material that provides a new concept approach to the synthesis of composite materials, and has a repeating structure of one-dimensional, two-dimensional and three-dimensional forms compared to the coordination compound of Formula 2 having a general form. .

<Formula 2>

 Examples of the two-dimensional coordination polymer are shown in the following formula (3).

<Formula 3>

Wherein M, L and S are as defined above.

In the two-dimensional coordination polymer represented by Formula 3, four multidentate ligands (L) and two monodentate ligands (S) are coordinated adjacent to a metal atom, and among these, the multidentate ligands are coordinated to another adjacent metal atom. Indicates that it is. In this case, the metal atom provides a coordination site to the ligand in the same form as the general coordination compound of Chemical Formula 2, but the ligand coordinating is coordinated with different metal atoms at various sites. In the coordination polymer of Chemical Formula 3, a ligand is a multidentate ligand coordinating to two metals at the same time to form a coordination polymer having a very regular lattice structure. Such a structure can be expanded in three dimensions, and unlike planar coordination polymers, the structure is further combined with metal atoms or ligands located above and below to form a three dimensional coordination polymer.

As the coordination polymer used to form the carbon-metal composite material in the present invention, a compound represented by the following Chemical Formula 1 may be used.

<Formula 1>

M _x L _y S _z

Wherein M represents at least one metal selected from the group consisting of transition metals, groups 13, 14, 15, lanthanide metals and actin metals;

L represents a multidentate ligand that simultaneously forms an ionic or covalent bond with two or more metal (M) ions;

S represents a single site ligand which forms an ionic or covalent bond with one metal (M) ion;

When x is the number of functional groups bondable with the metal (M) ions included in L, x, y, and z are yd + z ≦ 6x, x ≧ 1, y ≧ 1, and y + z ≧ 1. An integer that satisfies the relational expression of.

The compound of Formula 1 is a coordination polymer, in which a ligand L having several functional groups capable of simultaneously binding to two or more metal atoms or ions (hereinafter referred to as a multidentate ligand) connects metal atoms or ions to a network It is a substance obtained by forming a, and mainly takes a crystalline form. Such a coordination polymer may further include a single site ligand S capable of binding to a single metal atom or an ion separately from the multidentate ligand.

Chelating compounds may be mentioned as materials having a structure to be distinguished from the coordination polymer according to the present invention. The chelate compound refers to a compound in which a plurality of site ligands are bonded to metal ions, but in this case, they constitute only a general single compound and have a different structure from the coordination polymer of the present invention. That is, when a multidentate ligand such as ethylene diamine is coordinatively bound to a metal ion, in this case, it is not a network structure like the coordination polymer of the present invention, and a single coordination in which the multidentate ligand forms a chelate ring Since it is only a compound, it should be distinguished from the coordination polymer of the present invention. That is, the coordination polymer of the present invention essentially means that a network is formed through a multi-site ligand between neighboring metals, and in the case of a chelate complex formed by coordination at multiple sites with only one metal ion, the network cannot be formed. It is not possible to form the coordination polymer according to the present invention.

In the case of forming a network through the multidentate ligand L, the central metal ion or atom does not have to form a coordinating bond only with these multidentate ligands, and it is also possible to bind to the monodentate ligand if necessary. In other words, in the case of containing a multidentate ligand as described above, the single-site ligand S is further included if necessary. As such single-site ligand S, any ligand used in a general coordination compound can be selected without any limitation, and a ligand including nitrogen, oxygen, sulfur, phosphorus, arsenic, etc., in which an auxiliary electron pair is present, can be used. For example, H ₂ O, SCN ⁻ , CN ⁻ , Cl ⁻ , Br ⁻ , NH ₃ and the like may be used. However, single-site ligands do not have only one functional group, and in the case of forming a chelate ring as described above, it is also possible to use a multi-site ligand. That is, even if a multi-digit ligand such as 2, 3, 4, etc., if the metal atoms or ions can form a network through another ligand, their use is not limited.

The multi-site ligands capable of connecting the metal ions or atoms of the present invention to a network may be used without limitation as long as they have at least two functional groups capable of forming a network by forming a covalent bond or an ionic bond with the central metal. In particular, as described above, such multidentate ligands should be distinguished from multidentate ligands as chelating ligands that form a chelate ring by coordinating only one metal ion as described above. This is because it is difficult to form a coordination network polymer.

As such a multidentate ligand for forming a coordination polymer according to the present invention, for example, a trimethate ligand of Formula 4, a terephthalate ligand of Formula 5, and a 4,4′-bipyridine ligand of Formula 6 , 2,6-naphthalenedicarboxylate ligands of formula (7), and pyrazine ligands of formula (8).

<Formula 4>

<Formula 5>

<Formula 6>

<Formula 7>

<Formula 8>

Wherein R ₁ to R ₂₅ are each independently a hydrogen atom, a halogen atom, a hydroxy group, a substituted or unsubstituted C1-20 alkyl group, a substituted or unsubstituted C1-20 alkoxy group, substituted or unsubstituted Alkenyl group having 2 to 20 carbon atoms, substituted or unsubstituted aryl group having 6 to 30 carbon atoms, substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms, or Substituted or unsubstituted C2-C30 heteroaryloxy group is shown.

Several examples of such multidentate ligands are described in more detail in Christoph Janiak, Dalton Trans. , 2003, p2781-2804; and Stuart L. James, Chem. Soc. Rev. , 2003, 32 , 276-288. And incorporated herein by reference.

As the metal that binds to the multidentate ligand to form a coordination polymer, any metal that can provide a coordination site to the ligand can be used without any limitation. For example, a transition metal, Group 13, Group 14, Group 15, or lanthanide One or more metals selected from the group consisting of metals and actinic metals can be used. Among these, Fe, Pt, Co, Cd, Cu, Ti, V, Cr, Mn, Ni, Ag, Au, Pd, Ru, Os, Mo, Zr, Nb, La, In, Sn, Pb, and One or more metals selected from the group consisting of Bi can be used. Among them, at least one metal selected from the group consisting of Ag, Cu, Pd, Pt, Au, Ru, and Os has a high reduction potential as shown in FIG. 14, so that a composite material containing these metals is used as an electrode such as a fuel cell. In use, it has the advantage of minimizing side effects such as elution. As described above, the coordination polymer has a chemical formula of M _x L _y S _z , wherein in terms of coordination number, x, y and z are yd + z ≦ 6x, x ≧ 1, y ≧ 1, and y is an integer that satisfies the relationship of + z ≥ 1, where d represents the number of functional groups capable of bonding with the metal in the multidentate ligand L. For example, when L corresponds to a 4-dentate ligand, and the two-molecule of single-site ligand S forms a coordination bond with a metal, the basic monomer structure has a basic structure of MLS ₂ , and 1 (y) X 4 ( d) + 2 (z) = 6 X 1 (x) is satisfied. Since the multidentate ligand L is an essential component for constituting the network, its value should be 1 or more, and since the monodentate ligand S is an optional component that can be selected as necessary, its value should be 0 or more. These x, y and z does not represent a specific number of atoms in the nature that the compound is a polymer, it should be understood that those skilled in the art should be interpreted to mean the ratio of the metal and ligand present. Examples of the coordination polymer according to the present invention in the case where the central metal M is Cd and the multidentate ligand L is 4,4 ''-bipyridine are as shown in Formula 9 below, wherein x and y are 1, and z is Will have a value of 2).

<Formula 9>

The coordination polymer of Chemical Formula 9 shows a state in which 4,4′-bipyridine is coordinated to Cd, which is a central metal, and the terminal nitrogen atom included in 4,4′-bipyridine binds to one Cd ion, and then another By repeating the bonds in which the terminal nitrogen atoms are bonded to other Cd ions, a network can be formed. As a result, a highly regular coordination polymer having a two-dimensional lattice structure is obtained. The shape of such coordination polymer affects the final form of the carbon-metal composite material according to the present invention obtained by heat treatment, that is, periodicity. Therefore, proper control of the formation process of the coordination polymer can achieve the same effect as controlling the shape of the final product. As a method of controlling the crystal form of the coordination polymer, the reaction temperature, pH, and reaction time of the reaction in which the metal precursor and the ligand are combined, as well as the type of metal, the type of ligand and their concentration, etc. are appropriately changed, or the crystal state thereof is determined. It becomes possible by appropriately controlling the drying temperature and time for obtaining.

As described above, the carbon-metal composite material according to the present invention is obtained by heat-treating a powder containing the coordination polymer as described above. The heat treatment conditions are not particularly limited, but in an inert atmosphere at a melting point of about 600 ° C. to the metal, preferably at a temperature of about 600 ° C. to about 1,000 ° C., for about 0.1 to 10 hours, preferably about 0.5 to 3 hours It is preferable to heat-treat for a while. If the heat treatment temperature is less than 600 ° C, hydrogen in carbon is not completely removed, thereby increasing the resistance value, and thus the electrical conductivity may be reduced. When the melting point of the metal is exceeded, the metal melts to uniform the composite material. It may be difficult to form, which is not preferable. If the heat treatment temperature is less than 0.1 hours, a sufficient heat treatment effect may not be obtained, and if it exceeds 10 hours, there is a problem in that it is not economical because an increased heat treatment effect by an excess time cannot be obtained.

When the coordinating polymer is heat-treated as described above, all volatile components and combustible parts are evaporated and removed, thereby obtaining a carbon-metal nanocomposite having the same shape but having a reduced volume. In addition, since the shape of the coordination polymer is maintained even after the heat treatment because the shape of the shape before and after the heat treatment can be maintained, it is possible to easily control the particle shape of the final target.

In addition, after the heat treatment, it can be seen that the surface state of the coordination polymer crystal is changed so that the smooth surface is rough. As described above, the volatile component and the combustible portion are all evaporated and removed, and the metal component is coated on the surface. It is considered that the phenomenon occurs due to aggregation of the phase, and this results in a significant improvement of the specific surface area. Such improvement in the specific surface area of the carbon-metal composite material according to the present invention enhances its usefulness as a catalyst carrier for use in fuel cells and the like.

On the other hand, the carbon-metal composite material exhibits a certain periodicity. Such periodicity is due to the repeating structure of the coordination polymer in one, two, and three dimensional forms, which means that the repetitive high regularity of the coordination polymer is maintained even after heat treatment. Such periodicity can be measured by X-ray diffraction analysis, and the carbon-metal nanocomposite according to the present invention has at least one peak at a d-spacing of 6 nm or more, thereby indicating the presence of such periodicity. Can be. The d-spacing is preferably at least 6 nm, for example 10 to 100 nm. Such periodicity acts as an important factor for determining the physical properties of the carbon-metal composite material according to the present invention, and the nanoparticles having a mean particle size of less than 1 micron are uniformly arranged at the molecular level. It is possible to obtain a composite material containing metal particles of size and to form a composite particle of compact structure. As such, the periodic arrangement having a period larger than 6 nm is difficult to obtain only by using a structure directing agent. Only in the case of the carbon-metal composite material obtained by heat-treating a powder containing a coordination polymer according to the present invention. The same d-spacing of 6 nm or more is shown in X-ray diffraction analysis.

In addition, in the case of the carbon-metal composite material according to the present invention, the surface state of the coordinating polymer particle powder is substantially modified by heat treatment, so that the specific surface area is improved. This can be confirmed by the fact that the surface of the coordination polymer is smooth before the heat treatment (see FIG. 9), whereas the surface is considerably roughened after the heat treatment (see FIG. 11). As most of them are removed, the metals agglomerate on the surface, improving the specific surface area compared to before. As a result, the carbon-metal composite material according to the present invention has a specific surface area of about 30 m ² _/ g or more, preferably 50 to 500 m ² / g, as measured by the BET method. This improved specific surface area provides greater utility when used as a carrier for catalysts and the like. In particular, as described later, when the conductivity is excellent and the specific surface area is high, the usefulness is further increased.

In addition, the carbon-metal composite material according to the present invention exhibits excellent conductivity compared to the conventional carbon material because the carbon portion and the metal portion are dense periodically. This conductivity is 8 mΩ / sq. Under a pressure of 100 kg _f / cm ² . Hereinafter, a sheet resistance of preferably 0.01 to 5 mΩ / sq. The sheet resistance described above may be measured using a 4-probe method while applying pressure to a disk-shaped mold having a diameter of 13 mm using 0.1 g of the carbon-metal composite material. These low resistance values are possible because the carbon-metal composites of the present invention contain both carbon and metal parts in the molecule, and they are formed in a highly regular and precise arrangement, which cannot be achieved with conventional carbon materials. It is a number.

The carbon-metal composite material according to the present invention may exist in various forms such as particle form or rod form, and it is difficult to clearly determine the particle size due to the characteristics of the form, but visual measurement results through SEM photographs, etc. It can be seen that according to the size of approximately nanometers. In this case, the preferred average particle diameter of the carbon-metal composite material according to the present invention may be about 0.1 to 1 μm.

In the method for producing a carbon-metal composite material according to the present invention, the coordination polymer as a raw material thereof can be synthesized in an aqueous solution, and thus economical usefulness and safety are high, and the target product can be produced simply by heat treatment. There is an advantage that it is easy and template is unnecessary. In particular, the coordinating polymer as a raw material is obtained by coordinating a ligand as described above to the reaction solution in the form of an acid, for example, and coordinating with a metal generally present in the form of a salt. The reactants are in a mixed state. Here, it is also possible to separate only the coordination polymer and use only them in high concentration, but the carbon-metal according to the present invention while reducing the process cost by filtering and drying the mixed solution containing such a mixture as it is without a separate separation process. It is also possible to form a composite material. In this case, the powder before the heat treatment is in the form of a powder containing a coordination polymer. That is, such a powder may further include an organic compound that is an unreacted ligand in addition to the coordination polymer crystal. The content of the unreacted organic compound can be appropriately adjusted according to the appropriate control conditions of the reaction, it will be natural that the physical properties of the finally obtained carbon-metal composite material may vary.

In addition, the shape of the carbon-metal composite material can be obtained in various forms by controlling the shape of the coordination polymer, which also has the advantage that the shape of the particles is easily controlled according to the intended use. In addition, by forming a dense structure in which carbon and metal parts are periodically repeated, the conductivity is very high, which is useful for battery active materials, catalysts, catalyst carriers, hydrogen storage materials, conductive materials, magnetic materials, light emitters, and nonlinear optical materials. Can be used.

In particular, the carbon-metal composite material according to the present invention may have high utility as a catalyst carrier for use in fuel cells due to improved conductivity and specific surface area in addition to high regularity.

The basic structure of a direct methanol fuel cell (DMFC), which is a kind of fuel cell, is shown in FIG. 13. As shown in FIG. 13, an anode 20 to which fuel is supplied, a cathode 30 to which an oxidant is supplied, and an electrolyte membrane 10 positioned between the anode 20 and the cathode 30 are included. In general, the anode 20 is composed of an anode diffusion layer 22 and an anode catalyst layer 21, and the cathode 30 is composed of a cathode diffusion layer 32 and a cathode catalyst layer 31. The separating plate 40 includes a flow path for supplying fuel to the anode 20, and serves as an electron conductor for transferring electrons generated from the anode 20 to an external circuit or an adjacent unit cell. The separator 50 includes a flow path for supplying an oxidant to the cathode 30 and serves as an electron conductor for transferring electrons supplied from an external circuit or an adjacent unit cell to the cathode 30. In DMFC, an aqueous methanol solution is mainly used as a fuel supplied to the anode 20, and air is mainly used as an oxidant supplied to the cathode 30. The aqueous methanol solution transferred to the catalyst layer 21 of the anode 20 through the diffusion layer 22 of the anode is decomposed into electrons, hydrogen ions, carbon dioxide, and the like. Hydrogen ions are transferred to the cathode catalyst layer 31 through the electrolyte membrane 10, electrons are transferred to an external circuit, and carbon dioxide is discharged to the outside. In the cathode catalyst layer 31, hydrogen ions delivered through the electrolyte membrane 10, electrons supplied from an external circuit, and oxygen in the air delivered through the cathode diffusion layer 32 react to generate water.

The role of the catalyst layer in such a fuel cell system is very important, and in general, the specific surface area of the catalyst is preferable in terms of efficiency, and in the case of the carbon-metal composite material according to the present invention, the electrical conductivity is superior to that of the existing carrier material. Since the specific surface area is improved, the usefulness of the catalyst carrier in such a fuel cell system is particularly high.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

Example 1

3.8 g of nickel (II) acetate tetrahydrate and 2.0 g of trimesic acid were added to 100 ml of distilled water and stirred at 55 ° C. for 2 hours. The powder produced in the solution was separated using a nylon filter, washed several times with distilled water and dried in an oven at 100 ° C. for 2 hours to obtain coordination polymer crystals.

The obtained coordination polymer crystal was heat-treated at 900 ° C. for 1 hour under argon atmosphere to prepare a carbon-nickel composite material having the same shape as that of the coordination polymer crystal and having reduced volume before heat treatment.

The size of the nickel metal particles obtained by measuring the obtained carbon-nickel composite material by X-ray diffraction method was 18.3 nm. As shown in FIG. 1, a periodicity of 18 nm was observed in a low angle X-ray diffraction experiment.

SEM pictures of the coordination polymer crystal and the carbon-nickel composite material obtained after the heat treatment are shown in FIGS. 2 and 3. As can be seen from Figures 2 and 3, it can be seen that even though the volume decreases before and after the heat treatment to increase the density, the original crystal structure retains its shape and thus has a regular shape.

Example 2

3.8 g of nickel (II) acetate tetrahydrate and 2.0 g of trimesic acid were added to 100 ml of distilled water and stirred at room temperature for 2 hours. The powder produced in the solution was separated using a nylon filter, washed several times with distilled water and dried in an oven at 100 ° C. for 2 hours to obtain coordination polymer crystals.

The obtained coordination polymer crystal was heat-treated at 900 ° C. for 1 hour under argon atmosphere to prepare a carbon-nickel composite material having the same shape as that of the coordination polymer crystal and having reduced volume before the heat treatment.

As shown in FIG. 4, the periodicity of 29 nm was observed in the low angle X-ray diffraction experiment.

SEM pictures of the coordination polymer crystal and the carbon-nickel composite material obtained after the heat treatment are shown in FIGS. 5 and 6. As can be seen from Figures 5 and 6, it can be seen that even though the volume decreases before and after heat treatment to increase the density, the original crystal structure retains its shape and thus has a regular shape.

Example 3

A carbon-nickel composite material was prepared in the same manner as in Example 1 except that the synthesis temperature of the coordination polymer was changed from 55 ° C. to 100 ° C.

SEM pictures of the coordination polymer crystal and the carbon-nickel composite material obtained after the heat treatment are shown in FIGS. 7 and 8. As can be seen from Figures 7 and 8, it can be seen that even though the volume decreases before and after the heat treatment to increase the density, the original crystal structure retains its shape and thus has a regular shape.

Example 4

Except that the heat treatment temperature is 600 ℃ to perform the same process as in Example 1 to prepare the desired carbon-nickel composite material. In the low angle X-ray diffraction experiment on the obtained carbon-nickel composite, periodicity of 6.3 nm was observed.

Example 5

Except that the heat treatment temperature is 700 ℃ to perform the same process as in Example 1 to prepare the desired carbon-nickel composite material. In the low angle X-ray diffraction experiment on the obtained carbon-nickel composite, periodicity of 13 nm was observed.

Example 6

Except that the heat treatment temperature is 800 ℃ to carry out the same process as in Example 1 to prepare the desired carbon-nickel composite material. In the low angle X-ray diffraction experiment on the obtained carbon-nickel composite, periodicity of 17 nm was observed.

Example 7

4.89 g of terephthalic acid was dispersed in 250 ml of deionized water together with 2.36 g of a 50 wt% NaOH aqueous solution, and slowly heated to a boiling point. Then, 250 ml of an aqueous solution of 10.0 g of nitric acid was added thereto. It was visually confirmed that the white nitrate was formed at the same time as the silver nitrate solution was added. The mixture solution was heated and stirred for 20 minutes to maintain a boiling state. The powder produced in the solution was separated using a nylon filter, washed several times with distilled water and dried in an oven at 80 ° C. overnight to obtain silver (I) terephthalate, a crystal containing a coordination polymer, in the form of a white powder.

18 shows the results of the coordination polymers measured by X-ray diffraction. From Figure 18 it can be confirmed the synthesis of the coordination polymer.

The obtained powder containing silver (I) terephthalate crystals was heat-treated at 800 ° C. for 1 hour in an argon atmosphere to prepare a carbon-silver composite material having the same shape and reduced volume as the coordination polymer crystals before heat treatment.

The size of the silver metal particle which measured the obtained carbon-silver composite material by the X-ray diffraction method was 22.3 nm. SEM images of the coordination polymer crystal before the heat treatment and the carbon-silver composite material obtained after the heat treatment are shown in FIGS. 9 to 12, respectively. FIG. 9 is an SEM photograph of a coordination polymer crystal before heat treatment, and FIG. 10 corresponds to an enlarged photograph to more clearly distinguish the surface state. FIG. 11 is a SEM photograph of the carbon-silver composite material after heat treatment, and FIG. 12 corresponds to a magnified photograph to more clearly distinguish the surface state. As can be seen from FIG. 9 to FIG. 12, it can be seen that although the volume decreases before and after heat treatment and the density increases, the shape of the original crystal structure is maintained to have a regular shape. At the same time, through the enlarged SEM photographs of FIGS. 10 and 12, it can be seen that the surface state of FIG. 9, which was smooth before the heat treatment, becomes very rough as shown in FIG. 12 after the heat treatment, and thus the specific surface area is improved. .

Experimental Example 1: Conductivity Measurement

Each 0.1 g of the carbon-metal composite material, that is, the carbon-nickel composite material and the carbon-silver composite powder obtained in Examples 1, 2, 3, and 7, was made into a pellet of disk shape having a diameter of 13 mm, and each 100 kg _f / The sheet resistance was measured by a four-probe method using a CMT-SR1000 surface resistance meter (manufactured by Changmin Tech Co., Ltd.) under pressure of cm ² and 200 kg _f / cm ² , and the results are shown in Table 1 below.

In general, Ketjenblack of Akzo Nobel, a carbon material that is widely used as a carrier or conductive additive for catalysts, and Nippon Carbon, SP- 270 powder, and a type of graphite, creates a particle size of 6 microns of Timcal Inc. SFG6 each powder 0.1g into pellets of disc shape with a diameter of 13mm, was added to each state _f 100kg / cm ² and a pressure of 200kg _f / ² cm In Table 4, the sheet resistance was measured using the 4 probe method.

TABLE 1

division Measuring conditions Example 1 Example 2 Example 3 Example 7 Ketchen Black SP-270 SFG6 Sheet resistance (mΩ / sq.) 100kg _f / cm ² 5.1 2.7 2.1 <1 12.7 8.1 11.6 200 kg _f / cm ² 2.4 1.7 1.5 <1 9.0 7.5 4.3

As shown in Table 1, in the case of the carbon-metal composite materials (carbon-nickel composite material and carbon-silver composite material) prepared in Examples 1, 2, 3, and 7 of the present invention, a comparative example of a conventional carbon material Compared with KetjenBlack, SP-270 or SFG6 of 1 to 3, the sheet resistance is lowered to almost half or less, which shows very excellent conductivity. Especially for the carbon-silver composites obtained in Example 7, 1 mΩ / sq. It shows that the value is less than that a significant improvement in conductivity was achieved.

Experimental Example 2: Performance Experiment as Conductive Material

The material obtained in Example 2 was added to the silicon-graphite composite anode as a conductive material, and the effect thereof was measured. For comparison, Timcal's SFG6 powder having a particle size of 6 microns was used as a kind of graphite. Here, the capacity ratio is expressed as a percentage of the capacity obtained when the standard current is applied when the capacity obtained when 10 times (1 C) of the standard current (0.1 C) is applied.

TABLE 2

Conductive electrode plate additive Amount Capacity ratio (1C / 0.1C) Example 2 5 wt% 97.0% none 0% 26.8% SFG6 20 wt% 94.0%

As can be seen from the results of Table 2, the carbon-nickel composite material according to Example 2 of the present invention shows a capacity ratio of 97.0%, which SFG6, which is a conventional material, could not be achieved even at a large content of 20% by weight. It can be seen that the results are very excellent.

Experimental Example 3: Measurement of Specific Surface Area

The specific surface area of the carbon-silver composite material obtained in Example 7 by BET measurement using a Micromeritics company located in Norcross, Georgia, USA, showed 93.8 m ² / g (C-Ag composite material). When converted into carbon only, it showed a specific surface area corresponding to 440 m ² / g (C). From these results, it can be seen that the specific surface area of the carbon-metal composite material according to the present invention was greatly improved. This high specific surface area shows great utility as a catalyst carrier for fuel cells.

Experimental Example 4: Measurement of Average Particle Size

The average particle diameter of the carbon-silver composite material obtained in Example 7 by visually confirming the size of the 40 particles randomly extracted by using the SEM photographs of FIGS. 9 to 12 was about 0.75 μm. It can be seen that it is composed of nano-sized particles.

Experimental Example 5: TEM Measurement of Carbon-Nickel Composites

TEM photographs of the carbon-nickel composite material obtained in Example 1 are shown in FIGS. 13 and 14. As can be seen from FIG. 13, some nickel is present in a rod-like shape, and some carbon is present in the form of nanotubes or nanofibers. FIG. 14 is a further enlarged photograph of the image of FIG. 13, in which graphite carbon is developed around nickel particles, and carbon nanotubes or nanofibers are clearly present.

Experimental Example 6: X-ray Diffraction Analysis at Normal Angle

The carbon-nickel composites obtained in Examples 1, 4, 5, and 6 were subjected to X-ray diffraction analysis at a general angle, and the results are shown in FIG. 15. It can be seen from FIG. 15 that the carbon-nickel composite material is made of nickel and carbon, and in particular, graphite carbon is formed when the composite material is formed using a heat treatment temperature of 800 ° C. or higher.

Experimental Example 7: thermogravimetric analysis (TGA)

The coordination polymer obtained in Example 1 was heated at a rate of 10 ° C. per minute in a nitrogen atmosphere, and then subjected to thermogravimetric analysis and the results are shown in FIG. 16. From the results in FIG. 16, it can be seen that water is removed to approximately 350 ° C., pyrolysis proceeds in a temperature range of 400 to 500 ° C., and a complete carbon-nickel composite can be formed at a temperature of 500 ° C. or more.

Similarly, the carbon-nickel composites obtained in Examples 1, 4, 5, and 6 were subjected to thermogravimetric analysis experiments while heating up at a rate of 10 ° C. per minute in an air atmosphere, and the results are shown in FIG. 17. The increase in mass in the middle of the curve is considered to be due to the oxidation of nickel to nickel oxide, and in the case of composites obtained by heat treatment at 600 ° C and 700 ° C in Examples 4 and 5, respectively, it is 400 ° C or less. The carbon is removed at a temperature of, which means that the carbon constituting the carbon-nickel composite materials of Examples 4 and 5 is mostly amorphous carbon. In the case of the 800 ° C. heat treatment of Example 6, some of the carbon was removed at 400 ° C. or lower and others at a temperature thereafter such that the carbon constituting the carbon-nickel composite material according to Example 6 was amorphous carbon and graphite carbon. It can be seen that the mixture of. In the case of 900 ° C heat treatment of Example 1, most of the carbon is removed after 500 ° C it can be seen that the carbon constituting the carbon-nickel composite material of Example 1 is mostly graphite carbon.

The carbon-metal composite material according to the present invention is obtained by heat treatment of a coordination polymer, and is easy to control the form, and the structure in the particles is densely formed with high regularity, thus exhibiting excellent conductivity as well as improving specific surface area. It can be usefully used for an active material, a catalyst, a carrier for a catalyst, a hydrogen storage body, a conductive material, a magnetic body, a light emitting body, a nonlinear optical material, and the like.

Claims (27)

Obtained by heat treatment of the coordination polymer, Carbon and metals, Has a sheet resistance of 0.01 to 8 mΩ / sq. Under pressure conditions of 100 kg _f / cm ² , Carbon-metal composite material, characterized in that the coordination polymer is a compound having a monomer structure of the formula (1): <Formula 1> M _x L _y S _z Wherein M represents at least one metal selected from the group consisting of transition metals, groups 13, 14, 15, lanthanide metals and actin metals; L represents a multidentate ligand that simultaneously forms an ionic or covalent bond with two or more metal (M) ions; S represents a single site ligand which forms an ionic or covalent bond with one metal (M) ion; When x is the number of functional groups bondable with the metal (M) ions included in L, x, y, and z are yd + z ≦ 6x, x ≧ 1, y ≧ 1, and y + z ≧ 1. An integer that satisfies the relational expression of. The carbon-metal composite material as claimed in claim 1, wherein the sheet resistance is in the range of 0.01 to 5 mΩ / sq. The carbon-metal composite material according to claim 1, wherein the specific surface area is 30 to 500 m ² / g. The carbon-metal composite material according to claim 1, wherein the specific surface area is in the range of 50 to 500 m ² / g. The carbon-metal composite material according to claim 1, wherein the carbon-metal composite material exhibits an X-ray diffraction pattern having at least one peak at a d-spacing of 6 to 100 nm. The carbon-metal composite material according to claim 1, having an X-ray diffraction pattern having a d-spacing of 10 to 100 nm. 2. The carbon-metal composite material as defined in claim 1, wherein the average particle diameter is 0.01 to 1 micron. delete The carbon-metal composite material according to claim 1, wherein the metal is at least one selected from the group consisting of transition metals, group 13 elements, group 14 elements, group 15 elements, lanthanide metals, and actin metals. The method of claim 1, wherein the metal is Fe, Pt, Co, Cd, Cu, Ti, V, Cr, Mn, Ni, Ag, Au, Pd, Ru, Os, Mo, Zr, Nb, La, In, Sn , At least one carbon-metal composite material selected from the group consisting of Pb and Bi. The carbon-metal composite material according to claim 1, wherein the metal is at least one selected from the group consisting of Ag, Cu, Au, Pt, Pd, Pd, Ru, and Os. Obtained by heat treatment of the coordination polymer, Carbon and metals, Specific surface area of from 30 to 500 m ² / g, Carbon-metal composite material, characterized in that the coordination polymer is a compound having a monomer structure of the formula (1): <Formula 1> M _x L _y S _z Wherein M represents at least one metal selected from the group consisting of transition metals, groups 13, 14, 15, lanthanide metals and actin metals; L represents a multidentate ligand that simultaneously forms an ionic or covalent bond with two or more metal (M) ions; S represents a single site ligand which forms an ionic or covalent bond with one metal (M) ion; When x is the number of functional groups bondable with the metal (M) ions included in L, x, y, and z are yd + z ≦ 6x, x ≧ 1, y ≧ 1, and y + z ≧ 1. An integer that satisfies the relational expression of. 13. The carbon-metal composite material according to claim 12, wherein the specific surface area is in the range of 50 to 500 m ² / g. The carbon-metal composite material according to claim 12, having a sheet resistance of 0.01 to 8 mΩ / sq. Under a pressure condition of 100 kg _f / cm ² . 13. The carbon-metal composite material according to claim 12, wherein the carbon-metal composite material exhibits an X-ray diffraction pattern having at least one peak at d-spacings of 6 to 100 nm. The method according to any one of claims 1 to 7 and 9 to 15, which is used for an active material, a catalyst, a carrier for a catalyst, a hydrogen storage body, a conductive material, a magnetic body, a light emitting body, or a nonlinear optical material of a battery. Carbon-metal composite material, characterized in that. Heat-treating the powder containing the coordination polymer, Method for producing a carbon-metal composite material, characterized in that the coordination polymer is a compound having a unit structure of Formula 1 <Formula 1> M _x L _y S _z Wherein M represents at least one metal selected from the group consisting of transition metals, groups 13, 14, 15, lanthanide metals and actin metals; L represents a multidentate ligand that simultaneously forms an ionic or covalent bond with two or more metal (M) ions; S represents a single site ligand which forms an ionic or covalent bond with one metal (M) ion; When x is the number of functional groups bondable with the metal (M) ions included in L, x, y, and z are yd + z ≦ 6x, x ≧ 1, y ≧ 1, and y + z ≧ 1. An integer that satisfies the relational expression of. 18. The carbon-metal according to claim 17, wherein the coordination polymer-containing powder is obtained by separating and drying a solid component in a coordinating polymer mixed solution formed by coordinating a multidentate ligand, a monodentate ligand, or both. Method of manufacturing a composite material. 18. The method of claim 17, wherein the heat treatment temperature of the heat treatment step is 600 ° C to the melting point of the center metal contained in the coordination polymer. delete 18. The method of claim 17, wherein the coordination polymer forms a network structure obtained by interconnecting metals via the multidentate ligands. The method of claim 17, wherein the multidentate ligand is a trimethate ligand of Formula 4, a terephthalate ligand of Formula 5, a 4,4'-bipyridine ligand of Formula 6, 2,6-naphthalene of Formula 7 Method for producing a carbon-metal composite material, characterized in that at least one selected from the group consisting of dicarboxylate-based ligand, and pyrazine-based ligand of formula (8): <Formula 4>

<Formula 5>

<Formula 6>

<Formula 7>

<Formula 8>

Wherein R ₁ to R ₂₅ are each independently a hydrogen atom, a halogen atom, a hydroxy group, a substituted or unsubstituted C1-20 alkyl group, a substituted or unsubstituted C1-20 alkoxy group, substituted or unsubstituted Alkenyl group having 2 to 20 carbon atoms, substituted or unsubstituted aryl group having 6 to 30 carbon atoms, substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms, or Substituted or unsubstituted C2-C30 heteroaryloxy group is shown. The method according to claim 17, wherein the metal M is Fe, Pt, Co, Cd, Cu, Ti, V, Cr, Mn, Ni, Ag, Au, Pd, Ru, Os, Mo, Zr, Nb, La, In, Method for producing a carbon-metal composite material, characterized in that at least one selected from the group consisting of Sn, Pb, Bi. A carbon-metal composite material obtained by the manufacturing method according to any one of claims 17 to 19 and 21 to 23. A catalyst comprising the carbon-metal composite according to any one of claims 1 to 7 and 9 to 15. The catalyst of claim 25 wherein the carbon-metal composite is a carrier. A fuel cell comprising the catalyst according to claim 25.

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