JP4557562B2 - Amorphous carbon nanocapsule and method for producing the same - Google Patents

Description

  The present invention relates to an amorphous carbon nanocapsule, a method for producing the same, and a carbon material containing the amorphous carbon nanocapsule.

  Conventionally, carbon tubes such as carbon nanotubes and amorphous nanoscale carbon tubes (see Patent Document 1) developed by the applicant of the present application are known as nano-sized carbon materials having hydrogen storage ability.

However, these carbon tubes have a density as small as 0.01 g / ml or less, and when used as a hydrogen storage material, high density (compression) with molding is necessary to increase the storage efficiency per volume. As described above, since it is an aggregate of fibrous substances, it was difficult to mold and compress the carbon tube.
Japanese Patent No. 3355442 (Claim 1)

  In order to perform the molding and compression as described above, it is considered desirable to use a short-sized carbon-based hydrogen storage material instead of the fibrous carbon-based hydrogen storage material such as the carbon nanotube and the amorphous nanoscale carbon tube.

  Therefore, an object of the present invention is to provide a short-sized carbon-based hydrogen storage material having no fiber shape.

  In order to achieve the above object, the present inventors have conducted intensive studies, and as a result, by a specific production method using a specific catalyst, the length of amorphous carbon has a short size of 500 nm or less, and the capsule shape or It has been found that a hollow oval spherical carbon material can be obtained and that the obtained amorphous carbon nanocapsule has an excellent hydrogen storage capacity.

  In the claims and specification, this capsule-shaped or hollow elliptical carbon material is referred to as “amorphous carbon nanocapsule”.

  The present invention has been completed based on this finding, and has been completed. The following amorphous carbon nanocapsules, carbon material containing amorphous carbon nanocapsules, production method, gas containing the carbon material (hydrogen) An occlusion material and a gas (hydrogen) storage method using the gas (hydrogen) occlusion material are provided.

  Item 1. An amorphous carbon nanocapsule having a hollow elliptical spherical shape, having an outer diameter of 10 to 300 nm and a length of 30 to 500 nm.

  Item 2. A carbon material comprising amorphous carbon nanocapsules having a hollow ellipsoidal shape and having an outer diameter of 10 to 300 nm and a length of 30 to 500 nm.

Item 3 In X-ray diffraction (incident X-ray: CuKα),
The carbon network plane spacing (d ₀₀₂ ) calculated from the diffraction angle (2θ) of the peak derived from the amorphous structure is 3.7 mm or more, and the diffraction angle (2θ) is 25.1 degrees or less; the half width of the peak is 3.2 More than
The carbon network plane spacing (d ₀₀₂ ) calculated from the diffraction angle (2θ) of the peak derived from the graphite structure is 3.5 mm or less, and the diffraction angle (2θ) is 25.4 degrees or more; Less than 10 degrees,
In the Raman spectrum integral intensity of a peak having a maximum integrated intensity having a peak centered at 1540 cm ^-1 1650 cm ^-1 of the (Ia), of a peak having a maximum integrated intensity having a peak centered at 1200cm ^-1 ~1500cm ^-1 integral The integrated intensity ratio (Ia / Ib) to intensity (Ib) is 1.15 or less,
The true density is 2.5-3.5 g / cm ³ ,
The specific surface area is 400 m ² / g or more,
Item 3. The carbon material according to Item 2, wherein the hydrogen / carbon weight ratio by elemental analysis is 0.1 or less.

 Item 4. Amorphous carbon obtained by contacting a gaseous pyrolysis product of polyvinyl chloride with cobalt (II) chloride hexahydrate as a catalyst in an inert gas atmosphere at a temperature of 200 to 1500 ° C. A method for producing nanocapsules (or carbon materials containing amorphous carbon nanocapsules).

  Item 5: The gaseous pyrolysis product is produced by heating polyvinyl chloride having a thermal decomposition temperature of 200 to 500 ° C. in an inert gas atmosphere at a temperature equal to or higher than the thermal decomposition temperature of the polyvinyl chloride. The manufacturing method as described.

  Item 6. The method according to Item 4 or 5, wherein the cobalt (II) chloride hexahydrate is used in a powder form.

  Item 7 The production method according to any one of Items 4 to 6, wherein 1 to 100 parts by weight of cobalt (II) chloride hexahydrate is used with respect to 100 parts by weight of polyvinyl chloride.

  Item 8 A gas storage material comprising the carbon material according to Item 2 or 3.

  Item 9. A hydrogen storage material comprising the carbon material according to Item 2 or 3.

  Item 10. A gas storage method comprising storing a gas in a gas storage material containing the carbon material according to Item 2 or 3.

  Item 11. A hydrogen storage method, wherein hydrogen is stored in a gas storage material containing the carbon material according to Item 2 or 3.

  The amorphous carbon nanocapsules of the present invention are nano-particles having an outer diameter (diameter) of 300 nm or less and a length of about 500 nm or less, and are not fibrous like carbon nanotubes, so they can be easily compressed and molded.

  Since the amorphous carbon nanocapsules of the present invention are not fibrous like carbon nanotubes, they can be easily dispersed in a solvent or resin.

  Moreover, since the amorphous carbon nanocapsule of the present invention has a hollow shape, it can occlude gas not only in the structural wall but also in the hollow space.

Amorphous carbon nanocapsule and carbon material The shape of the amorphous carbon nanocapsule of the present invention is an elliptical capsule. Typically, the amorphous carbon nanocapsule of the present invention has a hollow oval shape, an outer diameter of 10 to 300 nm, and a length of 30 to 500 nm.

  The amorphous carbon nanocapsule of the present invention is a novel carbonaceous material that is completely different from the conventionally known amorphous nanoscale carbon tube, particularly in its shape.

  Transmission electron micrographs of the amorphous carbon nanocapsules (produced in Example 1 described later) of the present invention are shown in FIGS. As can be seen from FIGS. 1 to 4, the amorphous carbon nanocapsule of the present invention has a hollow elliptical spherical shape, and the length L of the amorphous carbon nanocapsule image obtained by a transmission electron microscope is 30 to 500 nm, particularly 100 to 300 nm. The outer diameter D is 10 to 300 nm, particularly 50 to 150 nm, and the ratio of the length L to the outer diameter D (L / D) is about 1 to 10, particularly about 2 to 5. The wall portion has a thickness of about 1 to 30 nm, particularly about 5 to 15 nm, and generally has a substantially uniform thickness over the entire circumference.

  The wall portion of the amorphous carbon nanocapsule of the present invention mainly has an amorphous structure. Here, “amorphous structure” means a carbonaceous structure consisting of an irregular carbon network plane, not a graphite structure consisting of a continuous carbon layer of regularly arranged carbon atoms. The graphene sheets are irregularly arranged, and the atomic arrangement is irregular. From an image obtained by a transmission electron microscope (TEM), which is a typical analysis method, the carbon nanocapsules having an amorphous structure according to the present invention have a size of the carbon net plane of one fine graphene sheet outside the amorphous carbon nanocapsules. It is smaller than 1 time of the diameter (diameter), in particular, 1 time or less of the outer diameter (diameter) of the amorphous carbon nanocapsule, particularly 10 nm or less, typically about 0.1 to 0.5 nm. This is apparent from the transmission electron micrograph shown in FIG.

  In addition, the amorphous carbon nanocapsules of the present invention partially contain a graphite structure. This is not necessarily clear from the transmission electron micrographs shown in FIGS. 1 to 4, but in X-ray diffraction, it is based on a peak based on amorphous carbon (amorphous carbon) and graphitic carbon (crystalline carbon). It can be seen from the fact that two peaks are observed.

In addition, the amorphous structure is the main structure, and the graphite structure is partially mixed. This means that almost entirely amorphous images are obtained from TEM image observation, and near 1360 cm ^{-1 in} the Raman spectrum. It can be seen from the fact that the crystallite size is reduced due to the strong peak and the structure is amorphous.

Amorphous carbon generally does not exhibit X-ray diffraction, but exhibits broad reflection. In the graphitic structure, since the carbon mesh planes are regularly stacked, the carbon mesh plane spacing (d ₀₀₂ ) is narrowed, and the broad reflection shifts to the high angle side (2θ) and becomes gradually sharper (in the 2θ band). The full width at half maximum becomes narrower), and it can be observed as a d ₀₀₂ diffraction line (d ₀₀₂ = 3.354 mm when regularly stacked in a graphitic positional relationship). In contrast, an amorphous structure generally does not exhibit X-ray diffraction as described above, but partially exhibits very weak coherent scattering.

  In the amorphous carbon nanocapsule of the present invention, two peaks derived from amorphous carbon are observed in the X-ray diffraction method (incident X-ray = CuKα). Therefore, in the amorphous carbon nanocapsule of the present invention, the main structure having poor crystallinity and the highly crystalline partial structure are mixed.

  The theoretical crystallographic characteristics of the amorphous carbon nanocapsules according to the present invention measured by the diffractometer method in the X-ray diffraction method (incident X-ray = CuKα) are defined as follows.

(1) The carbon network plane spacing (d ₀₀₂ ) calculated from the peak derived from the amorphous structure (2θ band, low angle side peak) is 3.7 mm or more, particularly 3.9 mm or more; diffraction angle (2θ) Is 25.1 degrees or less, particularly 23 degrees or less; the half-width of the 2θ band is 3.2 degrees or more, particularly 7 degrees or more.

Typically, in the amorphous carbon nanocapsule of the present invention, the diffraction angle (2θ) of the low-angle peak by X-ray diffraction is in the range of 18.9 to 22.6 degrees, and the carbon network plane spacing (d ₀₀₂₎ determined from this is obtained. ) Is in the range of 3.9 to 4.7 mm, and the full width at half maximum of the 2θ band is in the range of 7.6 to 8.2 degrees.

(2) The carbon network plane spacing (d ₀₀₂ ) calculated from the peak derived from the graphite structure (2θ band, high angle side peak) is 3.5 mm or less, particularly 3.45 mm or less; diffraction angle (2θ) Is 25.4 degrees or more, in particular 25.8 degrees or more; the half-width of the 2θ band is less than 10 degrees, in particular less than 5 degrees.

Typically, in the amorphous carbon nanocapsule of the present invention, the diffraction angle (2θ) of the high-angle peak by X-ray diffraction is in the range of 25.8 to 26.5 degrees, and the carbon network plane spacing (d ₀₀₂ ) determined from this is Is in the range of 3.36 to 3.45 mm, and the full width at half maximum of the 2θ band is in the range of 4 to 6 degrees.

  For example, as shown in FIG. 1, the carbon material of the present invention is a material containing the amorphous carbon nanocapsules of the present invention, and further contains soot, metal powder, particularly cobalt powder derived from a catalyst, and the like as impurities.

  The carbon material of the present invention is characterized by containing the amorphous carbon nanocapsules of the present invention, and typically has the following properties.

<Raman spectrum>
In the Raman spectrum integral intensity of a peak having a maximum integrated intensity having a peak centered at 1540 cm ^-1 1650 cm ^-1 of the (Ia), of a peak having a maximum integrated intensity having a peak centered at 1200cm ^-1 ~1500cm ^-1 integral The integrated intensity ratio (Ia / Ib) to intensity (Ib) is 1.15 or less, particularly about 0.85 to 1.13.

This integral intensity ratio has the following significance. That is, among the Raman-active vibrations of the graphite structure, the one whose spectral peak center is observed in the Raman shift range of 1540 cm ^{-1 to} 1650 cm ^-1 (especially around 1580 cm ^-1 ) is E _2g type vibration, and carbon Derived from lattice vibration in the hexagonal mesh plane. In contrast, the peak center of the spectrum is observed to range generally 1200cm ^-1 ~1500cm ^-1 (particularly near 1360 cm ^-1). This vibration is an A _1g type vibration, which is thought to be caused by the transition from the hexagonal symmetry to the lower symmetry or loss of the structure at the local crystal, and reflects the disorder of the crystal structure. .

Therefore, the range of 1540 cm ^-1 in 1650 cm ^-1 (especially 1580cm around ^-1) and peak (Ia) having the maximum integrated intensity having a peak centered at the range of 1200 cm ^-1 in 1500 cm ^-1 (particularly near 1360 cm ^-1) The integrated intensity ratio R (= Ia / Ib) with the peak (Ib) having a peak center at the maximum integrated intensity is an index having a strong correlation with the crystal structure.

Generally, when R is small, the crystallite size (L _a ) parallel to the basal plane is small. This reflects that the effect of the crystal structure of the local crystal becomes stronger when R is small. This reflects that the smaller R, the lower the crystallinity.

As can be seen from the Raman spectrum of diamond-like carbon, a broad spectrum having a peak center in the vicinity of 1360 cm ⁻¹ is considered to have a diamond-like structure, that is, a property derived from sp ³ bonds. Therefore, it is considered that the broad spectrum near 1360 cm ⁻¹ is mainly derived from the fact that _La is small, but may have the property of sp ³ bond. Here, a case where both the properties of sp ³ bonds is a case where in the structure sp ² is the main binding, partially sp ³ bond occurs. The portion where the sp ³ bond is generated has a dangling bond of carbon bond, or an atom other than carbon is considered to be bonded to the carbon atom, and is considered to be chemically active. This is presumed to be effective for gas storage at room temperature.

  In the carbon material of the present invention, the integrated intensity ratio R (= Ia / Ib) is preferably 1.0 or less, particularly 0.85 to 0.9.

<True density>
The carbon material of the present invention has a true density of about 2.5 to 3.5 g / cm ³ , particularly about 3.1 to 3.3 g / cm ³ .

  Here, the true density is measured as the weight of the sample by measuring the buoyancy exerted by the helium on the sample under a pressure of 1 to 10 MPa under the same procedure as the weight method used for measuring the hydrogen storage amount. The volume was determined from the buoyancy and calculated from the weight / volume.

<Specific surface area>
Carbon material of the present invention has a specific surface area measured by the BET method is 400 meters ² / g or more, in particular 550~700m ² / g.

<Hydrogen / carbon weight ratio>
The hydrogen / carbon weight ratio by elemental analysis is 0.1 or less, preferably 0.07 or less, more preferably 0.05 or less, and particularly 0.04 to 0.06.

Method for Producing Amorphous Carbon Nanocapsule The amorphous carbon nanocapsule of the present invention or the carbon material containing amorphous carbon nanocapsule is obtained by using a pyrolysis product (gaseous pyrolysis product) of polyvinyl chloride as a catalyst. It is produced by contacting cobalt hexahydrate at a temperature of 200 to 1500 ° C. in an inert gas atmosphere.

  As the raw material polyvinyl chloride, those in a wide range can be used, but in general, polyvinyl chloride having a decomposition temperature of 200 to 500 ° C. is preferred. Polyvinyl chloride can be used in various forms such as film, powder, pellet, and bar.

  The cobalt chloride hexahydrate used as the catalyst is preferably used in the form of powder. A particle having a particularly wide particle size can be used, but generally, an average particle size of 0.1 to 1000 μm, particularly 0.1 to 10 μm is preferable.

  The amount of the catalyst used for the polyvinyl chloride can be appropriately selected from a wide range, but generally it is preferably 1 to 100 parts by weight, particularly preferably 5 to 20 parts by weight, with respect to 100 parts by weight of the polyvinyl chloride.

  As the reaction apparatus, for example, as shown in FIG. 5, a heating furnace including a reaction tube 1 including a front furnace 1 f including an upstream heating apparatus 2 and a reaction furnace 1 r including a heating apparatus 3 can be used. As the reaction tube 1, one made of a material such as quartz or carbon can be used.

  In the embodiment shown in FIG. 5, the reaction tube 1 is provided with a suction port 10 at the right end for reducing the pressure in the furnace to a vacuum. In the reactor 1r, the catalyst described above, preferably placed in a container 4 such as a porcelain boat, is placed. On the other hand, the polyvinyl chloride as the carbon source is preferably placed in a container 5 such as a porcelain boat and placed in the front furnace 1f.

The atmosphere in the reaction tube 1 is an inert gas atmosphere by introducing an inert gas such as He, Ar, N ₂ or the like from an inlet 8 provided on the upstream side of the reaction tube 1. The pressure in the furnace during the reaction is 0.133 to 3.04 × 10 ⁵ Pa, particularly 13.33 to 1.01 while the inert gas is retained in the reaction tube 1 or while passing the inert gas through the reaction tube 1. × 10 ⁵ Pa (10 ^-3 torr to ³ atm, especially 10 ^-1 torr to ¹ atm)

  Next, the polyvinyl chloride is heated and thermally decomposed by the heating device 2. The heating temperature for this thermal decomposition is the decomposition temperature of polyvinyl chloride or higher, and is typically 200 to 500 ° C, particularly 300 to 400 ° C. At the same time, the catalyst is heated by the heating device 3. The heating temperature is 200 to 1500 ° C, preferably 200 to 1000 ° C.

  By this heat treatment, polyvinyl chloride is thermally decomposed in the front furnace 1f. As a result of this thermal decomposition, a thermal decomposition product carbonized and remaining in the front furnace 1f and a gaseous thermal decomposition product are generated. The latter gaseous pyrolysis product is used in the present invention. The gaseous pyrolysis product moves to the reactor 1r by diffusion or accompanied by the flow of the inert gas, where it travels with the catalyst at a temperature of 200-1500 ° C, preferably 200-1000 ° C. Contact. Thus, the amorphous carbon nanocapsule of the present invention is produced.

  The time required for the heat treatment can be appropriately selected from a wide range, but is generally about 0.5 to 2 hours. After completion of the reaction by the heat treatment, the temperature in the furnace is lowered to room temperature, and the carbon material containing the generated amorphous carbon nanocapsules is recovered.

Gas storage material and gas storage method The carbon material containing the amorphous carbon nanocapsules of the present invention is excellent in gas storage capacity. Therefore, this invention also provides the gas storage material which consists of a carbon material of the said invention.

  The carbon material comprising the carbon material of the present invention can stably occlude various gases at room temperature. Examples of the gas that can be stored by the gas storage material of the present invention include hydrogen, methane, argon, nitrogen, neon, and the like. The gas storage material of the present invention has an advantage that the gas can be stored stably at room temperature, and therefore has an extremely high industrial value.

  Since the carbon material of the present invention has many structures capable of stably adsorbing various gases, it can absorb various gases stably, and in particular, a gas having a very low critical temperature such as hydrogen. Further, it can be stably occluded at room temperature or in the vicinity thereof (for example, 0 ° C. to 40 ° C.)

  Furthermore, if the high-pressure gas cylinder container is filled with the carbon material of the present invention, it becomes possible to store more gas than can be stored in the same volume high-pressure gas cylinder container, and the amount of gas stored per unit volume can be improved. .

  Therefore, this invention also provides the gas storage method characterized by making the carbon material of the said invention occlude gas.

  Various methods can be adopted to store the gas using the gas storage material of the present invention. Generally, for example, at a temperature of about 0 to 40 ° C., the gas storage material made of the carbon material of the present invention is used. What is necessary is just to expose to the said gas atmosphere. Here, the pressure of the gas atmosphere is 0.03 MPa or more, preferably 0.2 MPa to 50 MPa, more preferably 0.5 MPa to 20 MPa.

  The gas storage method of the present invention has an advantage that gas such as hydrogen, which has been difficult to store at room temperature with conventional activated carbon, can be stored well at room temperature. The gas storage method of the present invention is also advantageous in that gas can be taken in and out only by pressure change. That is, the gas can be taken in and out as in the conventional gas cylinder.

  The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples, and various modifications can be made without departing from the present invention.

  In Examples and Comparative Examples, each physical property of the obtained carbon material was measured according to the method described above.

  In each example and comparative example, the hydrogen storage amount was measured as follows. That is, a capacity method hydrogen storage capacity measuring device with a sample tube volume of about 90 ml and a reservoir volume of about 360 ml is installed in an explosion-proof air constant temperature chamber at 25 ± 0.5 ° C. Measurements were performed according to the above. The gas temperature in the sample tube and the reservoir was measured using a Pt1000 high-accuracy thermometer (0 to 30 ° C., measurement accuracy ± 0.05 ° C., manufactured by Resca). The pressure was measured using a pressure sensor (Druck, “DPI145”; in the range of 0 to 20 MPa, with an error of ± 0.01% or less of the reading value). For the equation of state, NIST Standard Reference Database 12 Version 5.0 of NIST (National Institute of Standard and Technology) was used.

Example 1
As shown in FIG. 5, a reaction apparatus comprising a reaction tube 1 having a front furnace 1f having a heating apparatus 2 on the upstream side and a reaction furnace 1r having a heating apparatus 3 on the downstream side is used. As a catalyst, 3 g of cobalt (II) chloride hexahydrate (CoCl ₂ · 6H ₂ O) is placed in a container (magnetic boat) 4 in the center of the furnace, and polyvinyl chloride (PVC) is placed in the center of the front furnace 1f. ) 30 g was placed in a container (magnetic boat) 5 and installed.

  After introducing Ar gas from the inlet 8 on the upstream side of the reaction tube 1 to make an inert gas atmosphere, the reactor 1r is heated to 800 ° C. and the front furnace 1f while vacuuming from the suction port 10 to 0.133 Pa (0.1 torr). The mixture was heated to 400 ° C., reacted for 30 minutes, and then cooled to room temperature. 2 g of black product was obtained on the inner wall of the reaction tube 1.

  The transmission electron microscope (TEM) image of the obtained product is shown in FIGS. When these TEM images were observed, capsule-shaped products having an outer diameter of about 50 nm and a length of about 80 nm were observed as representative values. Further, from observation of these TEM images, it can be seen that an almost amorphous image is obtained.

  As a result of X-ray diffraction analysis of the product, a peak derived from amorphous carbon (2θ = 2.93 degrees, half width = 7.6 degrees) and a peak derived from graphitic carbon (2θ = 26.03 degrees, half width = 5 degrees) Two peaks were observed, and the d002 values calculated from these peaks were 0.405 nm and 0.342 nm, respectively.

  When the hydrogen storage amount of the product was measured, it showed a 2 wt% hydrogen storage amount.

  Moreover, the physical property of the carbon material containing the obtained amorphous carbon nanocapsule was measured by the above-mentioned method. The results are shown in Table 1 below.

  Thus, it is assumed that the amorphous carbon nanocapsules of the present invention have a large hydrogen storage capacity because of the hollow shape, gas can be stored not only in the hollow space but also in the wall structure. However, the details are still unclear.

Comparative Example 1
The reaction is the same as in Example 1 except that iron chloride tetrahydrate (FeCl ₂ · 4H ₂ O) is used instead of cobalt chloride (II) hexahydrate (CoCl ₂ · 6H ₂ O) as a catalyst. Went. 1 g of black product was obtained at the catalyst installation part.

  As a result of X-ray diffraction analysis of the product, no peak derived from the amorphous structure was observed, and a peak derived from graphite was obtained. The d002 value calculated from this peak was 0.338 nm.

  When a TEM image of the obtained product was observed, an iron compound was included inside the outer diameter of 50 to 300 nm, and carbon particulates having a graphite wall structure were observed. No amorphous carbon product was observed. When the hydrogen storage amount of this was measured, the hydrogen storage amount of 0.2 wt% was shown.

  Moreover, the physical property of the obtained carbon material was measured by the above-mentioned method. The results are shown in Table 1 below.

Example 2
As shown in FIG. 5, a reaction apparatus comprising a reaction tube 1 having a front furnace 1f having a heating apparatus 2 on the upstream side and a reaction furnace 1r having a heating apparatus 3 on the downstream side is used. 3g of catalyst cobalt chloride (II) hexahydrate (CoCl ₂ · 6H ₂ O) is placed in the container (magnetic boat) 4 in the center of the furnace and 30g of polyvinyl chloride (PVC) in the center of the front furnace 1f Was placed in a container (magnetic boat) 5. While maintaining a normal pressure Ar atmosphere, the temperature of the reactor was raised to 800 ° C. and the temperature of the front furnace was raised to 400 ° C. After the reaction for 30 minutes, the temperature was lowered to room temperature. 1.6 g of black product was obtained on the inner wall of the reaction tube.

  When a TEM image of the obtained product was observed, a capsule-like product having an outer diameter of 70 nm and a length of 120 nm was observed as a typical value. Moreover, when these TEM images were observed, they were almost entirely amorphous images.

  As a result of X-ray diffraction analysis of the product, a peak derived from amorphous carbon (2θ = 2.32 degrees, half width = 7.9 degrees) and a peak derived from graphitic carbon (2θ = 26.19 degrees, half width = 4.5 degrees) Two peaks were observed, and the d002 values calculated from these peaks were 0.398 nm and 0.340 nm, respectively.

  When the hydrogen storage amount of the obtained product was measured, it showed a hydrogen storage amount of 1.8 wt%.

  Moreover, the physical property of the carbon material containing the obtained amorphous carbon nanocapsule was measured by the above-mentioned method. The results are shown in Table 1 below.

Comparative Example 2
The reaction was carried out in the same manner as in Example 2 except that iron chloride tetrahydrate (FeCl ₂ · 4H ₂ O) was used instead of cobalt chloride (II) hexahydrate (CoCl ₂ · 6H ₂ O) as a catalyst. Went. The black product 0.8g was obtained in the catalyst installation part.

  When a TEM image of the obtained product was observed, an iron compound was included inside the outer diameter of 50 to 300 nm, and carbon particulates having a graphite wall structure were observed. No amorphous carbon product was observed. As a result of X-ray diffraction analysis, a peak derived from graphite was obtained, and the d002 value calculated from this peak was 0.338 nm. When the hydrogen storage amount of this was measured, it showed a 0.1 wt% hydrogen storage amount.

  Moreover, the physical property of the carbon material containing the obtained amorphous carbon nanocapsule was measured by the above-mentioned method. The results are shown in Table 1 below.

It is a transmission electron micrograph of the amorphous carbon nanocapsule obtained in Example 1 of the present invention. It is a transmission electron micrograph of the amorphous carbon nanocapsule obtained in Example 1 of this invention (higher magnification than FIG. 1). It is a transmission electron micrograph of the amorphous carbon nanocapsule obtained in Example 1 of the present invention (higher magnification than FIG. 2). It is a transmission electron micrograph of the edge part of the amorphous carbon nanocapsule obtained in Example 1 of this invention (higher magnification than FIG. 3). It is the schematic which shows an example of the manufacturing apparatus of the amorphous carbon nanocapsule of this invention.

Explanation of symbols

1 reaction tube
1f front furnace
1r Reactor 2 Heating device 3 Heating device 4 Container 5 Container 6 Valve 8 Inlet 10 Suction port

Claims (11)

An amorphous carbon nanocapsule having a hollow elliptical spherical shape, having an outer diameter of 10 to 300 nm and a length of 30 to 500 nm. A carbon material comprising an amorphous carbon nanocapsule having a hollow elliptical spherical shape and having an outer diameter of 10 to 300 nm and a length of 30 to 500 nm. In X-ray diffraction (incident X-ray: CuKα),
The carbon network plane spacing (d ₀₀₂ ) calculated from the diffraction angle (2θ) of the peak derived from the amorphous structure is 3.7 mm or more, and the diffraction angle (2θ) is 25.1 degrees or less; the half width of the peak is 3.2 More than
The carbon network plane spacing (d ₀₀₂ ) calculated from the diffraction angle (2θ) of the peak derived from the graphite structure is 3.5 mm or less, and the diffraction angle (2θ) is 25.4 degrees or more; Less than 10 degrees,
In the Raman spectrum integral intensity of a peak having a maximum integrated intensity having a peak centered at 1540 cm ^-1 1650 cm ^-1 of the (Ia), of a peak having a maximum integrated intensity having a peak centered at 1200cm ^-1 ~1500cm ^-1 integral The integrated intensity ratio (Ia / Ib) to intensity (Ib) is 1.15 or less,
The true density is 2.5-3.5 g / cm ³ ,
The specific surface area is 400 m ² / g or more,
The carbon material according to claim 2, wherein a hydrogen / carbon weight ratio by elemental analysis is 0.1 or less. The gaseous pyrolysis products of polyvinyl chloride, cobalt chloride (II) hexahydrate as a catalyst, in an inert gas atmosphere, to claim 1, wherein the contacting at a temperature of 200 to 1500 ° C. The manufacturing method of the amorphous carbon nanocapsule of description . The gaseous pyrolysis product is produced by heating polyvinyl chloride having a pyrolysis temperature of 200 to 500 ° C in an inert gas atmosphere at a temperature equal to or higher than the pyrolysis temperature of the polyvinyl chloride. Manufacturing method. The production method according to claim 4 or 5, wherein the cobalt (II) chloride hexahydrate is used in a powder form. The production method according to any one of claims 4 to 6, wherein 1 to 100 parts by weight of cobalt (II) chloride hexahydrate is used with respect to 100 parts by weight of polyvinyl chloride. A gas storage material comprising the carbon material according to claim 2. A hydrogen storage material comprising the carbon material according to claim 2. A gas storage method comprising storing a gas in a gas storage material containing the carbon material according to claim 2. A hydrogen storage method, wherein the gas storage material containing the carbon material according to claim 2 or 3 stores hydrogen.