JP5710693B2 - Microporous carbon-based material, method for producing microporous carbon-based material, adsorbent, and hydrogen storage method using microporous carbon-based material - Google Patents

Description

  The present invention relates to a microporous carbon-based material containing nitrogen, a method for producing a microporous carbon-based material, an adsorbent, and a hydrogen storage method using the microporous carbon-based material.

  Carbon is an attractive material with a variety of properties that do not seem to be made of a single element, such as high heat resistance, good transmission of electricity and heat, and resistance to chemicals. Recently, in addition to the applications that have been used so far, it is applied to materials that store high-value-added gas, such as hydrogen and methane, and devices that convert electrical energy into chemical energy for storage. Application to electrode materials for capacitors, lithium ion batteries, and fuel cells has been proposed.

  Thus, various carbon materials have been manufactured for a long time depending on the application. The carbon materials that have been proposed so far are how to skillfully bring existing materials such as pitch, which is a heavy aromatic compound obtained from petroleum and coal, and general-purpose polymers into carbon, and bring them closer to the target structure and characteristics. It was prepared with a point. In the future, in order to prepare carbon materials with new functions, it is necessary to design and synthesize carbon materials at the molecular level, for example, to produce carbon materials that have a regular structure at the micro level. It is done. However, it is expected that it is difficult to synthesize such a carbon material by the conventional preparation methods.

  As a method for obtaining mesoporous carbon having a regular structure, it is disclosed that mesoporous carbon having a regular structure is obtained using mesoporous (mesoporous) silica as a template. However, with this method, a regular mesopore structure can be obtained, but a regular micropore structure with smaller pores cannot be obtained (see Non-Patent Document 1 and Non-Patent Document 2).

  Therefore, the group of the inventors of the present invention uses a porous material as a mold, introduces an organic substance into the surface of the porous material and the inside of the pores, heats it, and then removes the porous material. Have proposed to obtain a carbon material (zeolite template carbon; hereinafter referred to as MPC) having a regular structure having a long period (see Patent Documents 1 and 2 and Non-Patent Documents 3 and 4). Further, it has been proposed to use an organic substance containing a nitrogen atom as an organic compound to be introduced into the porous material, and to subject this organic substance to chemical vapor deposition. By this reaction, a carbon material that reflects the shape of the pores of the porous material used for the mold and is doped with nitrogen is obtained. This carbon material has nano-level structural regularity and vacancies reflecting the shape of the porous material used as a template, and the two-dimensional stacking regularity of carbon is suppressed, and a novel nitrogen-doped carbon material. It is a porous carbon material (nitrogen-doped zeolite template carbon, nitrogen-doped microporous carbon; hereinafter referred to as nitrogen-doped MPC) (see Patent Document 3).

Japanese Patent No. 3951567 JP 2003-206112 A JP 2006-310514 A

RooR, et al., J. Phys. Chem. B1999; 103: 7743-7746 LeeJ, et al., Chem. Commun. 1999; 2177-2178 Kyotani, et al., Chem. Commun. 2000; 2365-2366 MaZX, et al., Carbon, 40: pp. 2367-2374 (2002)

In the method for producing nitrogen-doped MPC (hereinafter referred to as conventional nitrogen-doped MCP) disclosed in Patent Document 3, Na-Y zeolite is used as a template porous material, and furfuryl alcohol is used as an organic compound to be introduced. Yes. And after filling a furfuryl alcohol with a zeolite, acetonitrile is further added as a nitrogen source, and the target carbon material is obtained by chemical vapor deposition (CVD). However, the carbon material (conventional nitrogen-doped MCP) obtained by this method has a low nitrogen content, and the N / C element ratio is limited to about 0.05 to 0.06. In addition, in the conventional nitrogen-doped MPC manufacturing method, it is difficult to obtain a carbon material having a high nitrogen content and a BET specific surface area of 1500 m ² / g or more.

The present invention has been made to solve the above problems, and a method for producing a microporous carbon-based material according to the present invention includes a substituted or unsubstituted imidazole or oxazole on the surface of a porous material and the inside of pores. , A first step of introducing any nitrogen-containing organic compound selected from pyrazole, triazole, pyridazine, pyrimidine, pyrazine, triazine, and tetrazine compounds, and heating and carbonizing the nitrogen-containing organic compound; It has the 2nd process which introduce | transduces an organic compound into the surface of a porous material and the inside of a void | hole, and vapor-phase carbonizes, and the 3rd process of removing a porous material after vapor-phase carbonization, It is characterized by the above-mentioned. And Moreover, the method for producing a microporous carbon material according to the present invention includes a first step of introducing a nitrogen-containing organic compound into the surface of the porous material and inside the pores, and heating and carbonizing the nitrogen-containing organic compound. A second step of introducing an organic compound into the surface of the porous material and the pores after the carbonization and vapor-phase carbonizing; and a third step of removing the porous material after the vapor-phase carbonization; In addition, the microporous carbon-based material obtained in the third step of removing the porous material is immersed and impregnated in the transition metal salt solution to obtain a mixed solution. An immersion step, a separation step of separating the microporous carbon-based material adsorbed with the transition metal by centrifugation after stirring the mixed solution under reduced pressure, and a microporous carbon-based material adsorbed with the transition metal obtained by the separation With reducing agent solution Liquid phase reduction by mixing and adsorbing the transition metal adsorbed on the surface and micropores of the microporous carbon material, and washing the microporous carbon material on which the transition metal is deposited with pure water And a drying step of drying .

The hydrogen storage method using the microporous carbon material according to the present invention is a microporous carbon material having nitrogen in the carbon skeleton, a three-dimensional long-period ordered structure, and micropores inside. Then, using an adsorbent comprising a microporous carbon-based material having a BET surface area of 1500 m ² / g or more and a nitrogen / carbon element ratio of 0.07 or more, hydrogen is applied in the range of −40 ° C. to 150 ° C. It is characterized by occlusion and release.

  According to the present invention, a microporous carbon-based material having a large amount of gas adsorption such as gas having polarity such as water vapor, acidic gas, oxygen-containing hydrocarbon vapor and the like can be obtained.

According to the method for producing a microporous carbon material according to the present invention, a three-dimensional long-period ordered structure and micropores having nitrogen in the carbon skeleton and reflecting the structural characteristics of the porous material are obtained. And a microporous carbon-based material having a BET surface area of 1500 m ² / g or more and a nitrogen / carbon element ratio of 0.07 or more.

  According to the present invention, since the microporous carbon material according to the present invention is used, a high-performance adsorbent having a large amount of gas adsorption such as gas having polarity such as water vapor, acid gas, oxygen-containing hydrocarbon vapor, etc. can get.

  According to the present invention, since the microporous carbon material according to the present invention is used, hydrogen can be stored and released efficiently at a low temperature.

(A) It is a figure which shows the porous material used for the manufacturing method of the microporous carbon material which concerns on embodiment of this invention. (B) It is a figure which shows the composite_body | complex of a porous material and a microporous carbon type material. (C) It is a figure which shows typically an example of a microporous carbon-type material. (D) It is a figure which shows typically an example of the microporous carbon material which concerns on other embodiment of this invention. It is an example of the nitrogen-containing organic compound used for the manufacturing method of the microporous carbon material which concerns on embodiment of this invention. It is an image figure where a transition metal coordinates to the microporous carbon material which concerns on embodiment of this invention. It is a table | surface which shows the result of the sample name of an Example and a comparative example, the kind of cation of a zeolite, a carbon precursor, a BET surface area, N / C, and XRD. It is a table | surface which shows the presence state of nitrogen in each sample analyzed by XPS. It is a figure which shows the water vapor | steam adsorption isotherm of a microporous carbon type material. It is a figure which shows the XRD pattern of a microporous carbon material. It is a graph which shows the hydrogen storage ability of Example 4, 7 in 30 degreeC. It is a graph which shows the hydrogen storage ability of Example 4, 7 in 100 degreeC.

  Hereinafter, a microporous carbon material, a method for producing a microporous carbon material, an adsorbent, and a hydrogen storage method using the microporous carbon material according to an embodiment of the present invention will be described.

<Microporous carbon material>
FIG. 1 (c) schematically shows an example of the microporous carbon material according to the embodiment of the present invention. The microporous carbon-based material 2 according to the embodiment of the present invention shown in FIG. 1 (c) has an organic compound as a carbon source in the micropores (holes) 1a of the porous material 1 shown in FIG. 1 (a). After the introduction, heat treatment is performed to obtain a composite 3 of the porous material 1 and the microporous carbon-based material 2 as zeolitic carbon shown in FIG. 1B, and thereafter, only the porous material 1 is removed. It is obtained. The microporous carbon-based material 2 according to the embodiment of the present invention has a three-dimensional long-period ordered structure 2a having nitrogen in the carbon skeleton and reflecting the structural characteristics of the porous material used as a template. Micropores 2b, a BET surface area of 1500 m ² / g or more, and a nitrogen / carbon element ratio of 0.07 or more. FIG. 1D shows a microporous carbon-based material 5 according to another embodiment of the present invention, which will be described later, and the micro according to the embodiment of the present invention obtained as zeolitic carbon. The porous carbon-based material 2 carries the transition metal 4. Details will be described below.

  The microporous carbon-based material 2 according to the embodiment of the present invention reflects the structural characteristics of the porous material 1 having a specific three-dimensional regular structure, which is a mold material used in the production thereof, and has a diameter. Is a porous carbon material having a structure in which pores (micropores) 2b having a diameter of 0.1 to 2 nm are connected in a network. Specifically, as shown in FIG. 1C, the microporous carbon-based material 2 according to the embodiment of the present invention has a three-dimensional long-period regular structure 2a and has micropores 2b inside. . More specifically, the microporous carbon material 2 according to the embodiment of the present invention has a structure in which the distance between the carbon chains is regularly repeated over a long period three-dimensionally at an arbitrary interval. It is preferable that the distance between the carbon chain that forms the three-dimensional long-period regular structure 2a is 0.5 to 100 nm. More preferably, the distance between the carbon chains is preferably 0.7 to 50 nm. Further, the distance between the carbon chain is more preferably 0.7 to 2 nm. In IUPAC (International Union of Pure and Applied Chemistry), pores having a diameter of 2 nm or less are micropores, and pores having a diameter of 2 to 50 nm are mesopores ( mesopore), and pores having a diameter of 50 nm or more are defined as macropores. Substances having micropores are collectively referred to as a microporous material.

The microporous carbon-based material 2 according to the embodiment of the present invention has a BET surface area of 1500 m ² / g or more and a nitrogen / carbon molar ratio of 0.07 or more. The microporous carbon-based material 2 according to the embodiment of the present invention has a large BET surface area by having the three-dimensional long-period regular structure 2a and the micropores 2b. Although details are unknown, it is generally preferable that the BET surface area be large for application to a gas adsorbent. The presence of micropores is also considered important, although it is affected by the size of molecules to be adsorbed. On the other hand, it is considered that mesopores are not very effective when applied to the aforementioned uses. For this reason, in order to express a desired high function, it is important that a relatively large number of micropores are present, and it is considered that it is better to have as few mesopores as possible. As a guide, the BET surface area is preferably 1500 m ² / g or more. Moreover, it is more preferable that it is 2000 m < ² > / g or more, Furthermore, it is preferable that it is 2500 m < ² > / g or more.

  In manufacturing the microporous carbon material 2 according to the embodiment of the present invention, as described later, the porous material 1 having a specific three-dimensional regular structure is used as a template to reflect the structural characteristics. It is preferable to use the obtained template method. The porous material to be used preferably has a gap between carbon chains of 0.5 to 100 nm. Moreover, it is more preferable that it is 0.7-50 nm between carbon chains of a porous material, and it is still more preferable that it is 0.7-2 nm. Thus, by using a carbon material having a structure in which the carbon chain is regularly repeated over a long period at an arbitrary interval between the carbon chains, the three-dimensional long period regular structure 2a reflecting the structure is obtained. A microporous carbon material 2 having micropores 2b is obtained.

  Moreover, the microporous carbon material 2 according to the embodiment of the present invention has nitrogen in its carbon skeleton. By having nitrogen in the skeleton, new functions are added, such as an improvement in hydrogen adsorption power and specific gas adsorption power. In particular, when nitrogen is doped so that the nitrogen / carbon molar ratio is 0.07 or more, a function of improving a specific gas adsorption power is exhibited. When the nitrogen / carbon molar ratio is 0.09 or more, a more sufficient nitrogen doping effect can be obtained. When the nitrogen / carbon molar ratio is lower than 0.07, the effect of nitrogen doping may not be sufficiently exhibited. Further, as the nitrogen doping amount is increased, new functional improvement can be expected. However, if too much is added, formation of the pore structure becomes difficult, and the surface area may be reduced.

  The microporous carbon-based material 2 according to the embodiment of the present invention has a higher gas adsorbing power and the like as its structural feature is less two-dimensional stacking regularity. For example, when powder X-ray diffraction measurement is performed, it is preferable that the obtained X-ray diffraction pattern has as few diffraction peaks as possible that usually appear in the vicinity of 26 ° indicating two-dimensional stacking regularity. The presence of diffraction peaks appearing near 26 ° means an increase in the nonporous carbon layer and a decrease in the BET surface area.

In addition, the microporous carbon material according to the embodiment of the present invention preferably has a relative pressure (P / P ₀ ) indicating a maximum value of the slope of the water vapor adsorption isotherm at 25 ° C. of 0.6 or less. . As the water vapor is adsorbed at a lower relative pressure, the hydrophilicity is improved by nitrogen doping. However, if the relative pressure (P / P ₀ ) is 0.6 or more, the effect of nitrogen doping cannot be said to be sufficient, and the functionality. The effect of grant cannot be obtained.

In the microporous carbon material according to the embodiment of the present invention, as the state of nitrogen introduced into the carbon skeleton, the pyridine type nitrogen incorporated as a hetero atom in the aromatic ring is converted to the moles of all nitrogen substituents. The ratio is preferably 10% or more. As an introduction state of nitrogen, an introduction state by pyridine nitrogen, quaternary nitrogen, nitro group or the like can be considered. When the nitrogen is pyridine type nitrogen, it is possible to achieve both a nitrogen / carbon molar ratio of 0.07 or more and a BET surface area of 1500 m ² / g or more.

The microporous carbon material according to the embodiment of the present invention has hydrophilicity by nitrogen doping with an N / C element ratio of 0.07 or more while maintaining a high surface area of BET surface area of 1500 m ² / g or more. Is a feature. Thus, since it has hydrophilicity by nitrogen dope, the microporous carbon material according to the embodiment of the present invention is an adsorbent such as gas having polarity such as water vapor, acid gas, oxygen-containing hydrocarbon vapor, etc. Useful as. Moreover, since the microporous carbon material according to the embodiment of the present invention has hydrophilicity, an improvement in performance can be expected when applied as an electrode of an electric double layer capacitor (EDLC). In general, the electrolyte solution of EDLC has a large polarity, and considering the affinity (wetting property) with the electrode surface, an electrode exhibiting hydrophilicity is desired. Carbon materials not doped with nitrogen, including activated carbon and microporous carbon-based materials, are highly hydrophobic, and modify affinity (wetting) when applied to capacitors and the like. For this reason, secondary surface modification treatment that does not involve the direct performance of EDLC may be performed. In contrast, the microporous carbon material according to the embodiment of the present invention does not need to be subjected to secondary surface modification treatment, and can be used as it is. For this reason, a better effect can be expected. In addition, in an adsorption heat pump that uses adsorption / desorption of water vapor, since performance can be significantly improved as compared with zeolite currently used as an adsorbent, performance improvement such as downsizing of the apparatus can be expected.

  In the microporous carbon material 5 according to the embodiment of the present invention shown in FIG. 1 (d), the transition metal 4 is supported on the surface of the micropores 2b, and new functionality can be expressed. Here, the surface of the micropore 2b refers to the surface of the micropore 2b of the microporous carbon material 2 as the zeolitic carbon constituting the microporous carbon material 5, and also refers to the surface inside the micropore 2b. The transition metal 4 may be supported not only on the surface of the micropore 2b but also on the portion other than the micropore 2b, that is, on the outer surface of the microporous carbon material 2 as zeolite carbon. The transition metal 4 is preferably supported in the microporous carbon material 5 within a concentration range of 0.01 to 10 wt%. In this case, the transition metal 4 is supported on the surface of the micropore 2b in the form of fine particles. When the supported transition metal 4 is 0.01 wt% or less, the function of the transition metal cannot be sufficiently obtained. On the other hand, when the supported transition metal 4 is 10 wt% or more, the BET surface area decreases or the transition metal fine particles become too large. The size of the fine particles of the transition metal is preferably 3 nm or less, but a smaller one is desirable for maintaining the function of the transition metal and a high BET surface area. When the transition metal concentration is 0.01 to 10 wt%, a microporous carbon-based material capable of expressing the function of the supported transition metal while maintaining the inherent pore function can be obtained.

  The metal to be supported is preferably a transition metal from the viewpoint of imparting functionality, but may be a metal other than the transition metal. In addition, the transition metal is not limited to a single substance, but two or more kinds of metals may be supported, or may be an alloy. In addition, when providing oxidation resistance as a function, it is desirable to use platinum among transition metals. When platinum is used, it is preferably used in the range of 0.05 wt% to 6 wt%. In order to obtain the function of the metal to be supported, at least 0.05 wt% or more is more preferable. If a large amount of metal is used, it becomes a factor of cost increase. In particular, when a noble metal such as platinum or a rare metal is used, the cost becomes high. Although it is technically possible to carry more than this, there are many cases where no improvement in performance can be expected with respect to the proportion of loading.

  If the reducing atmosphere can be maintained in a usage environment such as a production process or a hydrogen storage application, the metal can be used without imparting oxidation resistance to the metal to be supported. A transition metal preferable for supporting is not limited as long as it is a transition metal that forms a metal bond type or an interstitial hydride (MH bond). From the viewpoint of resources, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zirconium, molybdenum, ruthenium, rhodium, palladium, and lanthanoids (particularly lanthanum, cerium) are exemplified.

In the microporous carbon material 5 according to the embodiment of the present invention, it is preferable that the volume occupied by the micropores 2b is 0.8 cm ³ / g or more in a state where the transition metal 4 is supported. The volume occupied by the micropores 2b is more preferably 1.0 cm ³ / g or more, and still more preferably 1.2 cm ³ / g or more. In addition, the microporous carbon material 5 according to the embodiment of the present invention preferably has a BET surface area of 1500 m ² / g or more in a state where the transition metal 4 is supported. The BET surface area is more preferably 2000 m ² / g or more, and further preferably the BET surface area is 3000 m ² / g or more. When the volume occupied by the micropores is 0.8 cm ³ / g or less or the BET surface area is 1500 m ³ / g or less, sufficient hydrogen storage performance of the microporous carbon material may not be obtained. When the microporous carbon material according to the embodiment of the present invention is used as a hydrogen storage material, the proportion of the volume occupied by the micropores is preferably as large as possible, but the volume A and the diameter occupied by the micropores are 2 to 2. The ratio A / B of the volume B occupied by pores (mesopore volume) in the range of 50 nm is at least 2 or more, preferably 3 or more. When the ratio A / B is decreased, the hydrogen storage performance may be decreased even if the specific surface area is the same.

  The microporous carbon material according to the embodiment of the present invention has a higher gas adsorbing power and the like as the structural feature is less two-dimensional stacking regularity. For example, when powder X-ray diffraction measurement is performed, it is preferable that the obtained X-ray diffraction pattern has as few diffraction peaks as possible that usually appear in the vicinity of 26 ° indicating two-dimensional stacking regularity. The presence of diffraction peaks appearing near 26 ° means an increase in the nonporous carbon layer and a decrease in the BET surface area.

  The microporous carbon material according to the embodiment of the present invention can occlude and release hydrogen in the range of −40 ° C. to 150 ° C. In particular, when a transition metal is supported, the occlusion ability is improved with an increase in temperature. The upper limit of 150 ° C. takes into account the stability of the material and the degree of freedom in designing the housing filled with the material. Considering the use of waste heat of the fuel cell, it is desirable to use at 100 ° C. or lower. In addition, the microporous carbon material according to the embodiment of the present invention can easily release not only the hydrogen storage capacity but also the stored hydrogen. For this reason, it becomes possible to use effectively as a hydrogen storage material. Thus, in the hydrogen storage method according to the embodiment of the present invention, since the microporous carbon material according to the embodiment of the present invention is used, it is possible to efficiently store and release hydrogen at a low temperature.

<Method for producing microporous carbon-based material>
The microporous carbon material according to the embodiment of the present invention includes a first step of introducing a nitrogen-containing organic compound into the surface of the porous material and inside the pores, and heating and carbonizing the nitrogen-containing organic compound. It is obtained by a production method comprising a second step of introducing an organic compound into the surface of the porous material and inside the pores to vapor-phase carbonize and a third step of removing the porous material. In order to obtain the structural characteristics described above, a porous material having a structure in which pores are formed in the structure and the pores are connected in a network is used as a template. Then, an organic compound containing nitrogen is introduced into the surface of the porous material and inside the pores, and this is heated to carbonize the organic compound containing nitrogen, and a new organic compound is introduced to introduce nitrogen. To deposit. Next, the porous material which is a template is removed. By this method, a microporous carbon-based material can be easily manufactured. In addition, when depositing nitrogen, heating is performed at a temperature higher than the heating / carbonization temperature in the first step, and then the porous material is removed to obtain a microporous carbon material having a larger BET surface area. Can do. Although details are unknown, the above-described continuous treatment makes it possible to uniformly form a carbon material inside the porous material and functionally dope the carbon material with nitrogen. Furthermore, it is thought that it becomes easy to produce | generate the porous carbon material which has the structure repeated regularly over a long period and was provided with hydrophilicity.

  In the production of the microporous carbon material according to the embodiment of the present invention, it is necessary that the nitrogen-containing organic compound introduced into the porous material can be liquefied or vaporized. Examples of the liquefaction method include heating above the melting point, dissolving in a solvent, and pressurization. The vaporization method includes heating to the boiling point or higher, reducing the atmosphere to a reduced pressure, and the like.

  Examples of the nitrogen-containing organic compound include a cyano group and amino group-substituted hydrocarbon, a 5-membered nitrogen-containing heterocyclic compound, and a 6-membered nitrogen-containing heterocyclic compound. In order to improve the doping amount of nitrogen, particularly to obtain the target microporous carbon material of the present invention having a nitrogen / carbon molar ratio of 0.07 or more, dicyanomaleonitrile substituted with two or more amino groups and cyano groups And ethylene and propylene derivatives. In addition, examples of the cyclic compound include nitrogen-containing organic compounds such as substituted or unsubstituted imidazole, oxazole, pyrazole, triazole, pyridazine, pyrimidine, pyrazine, piperidine, piperazine, triazine, tetrazine, and derivatives thereof. Thus, as the nitrogen-containing organic compound that can be used, the compounds shown in FIGS. In addition, it is preferable to use the compound which can anticipate dehydration condensation with the silanol group of the porous material used as a casting_mold | template, and it is especially preferable to use the hydroxyl group substituted body of the compound mentioned above individually or in mixture.

When introducing the organic substance into the pores of the porous material, it is preferable to depressurize the porous material in advance. When carbonizing an organic substance, any method may be used as long as the porous material of the template is stable and only the carbonization reaction of the organic substance occurs. Usually, the impregnated nitrogen-containing organic compound (or a polymer thereof) can be carbonized by heating a composite in which a porous material used as a template is impregnated with a nitrogen-containing organic compound. The heating temperature can be appropriately selected depending on the nitrogen-containing organic compound used, but is usually in the range of 400 to 1500 ° C. Moreover, it is more preferable that it exists in the range of 500-1100 degreeC, and it is further more preferable that it exists in the range of 600-900 degreeC. Moreover, the range of 650-800 degreeC is preferable, and the range of 650-750 degreeC is further more preferable. Also, an appropriate temperature can be appropriately selected according to the heating time. The heating time is preferably a time during which the nitrogen-containing organic material to be impregnated is sufficiently carbonized, and an appropriate time can be selected depending on the organic compound used and the use temperature. The analysis method disclosed herein can be applied to analyze the product and set the time required for carbonization based on the results. The carbonization treatment can also be performed under reduced pressure or under vacuum. It can also be carried out under pressure. Furthermore, it can be carried out in an inert gas atmosphere, which may be preferred. Examples of the inert gas include N ₂ gas, helium, neon, and argon.

  After the first step, next, a second step is performed in which an organic compound is introduced into the surface of the porous material and inside the pores to vapor-phase carbonize. The organic compound introduced here is vaporized and treated according to chemical vapor deposition.

  The chemical vapor deposition method is an industrial technique for producing a thin film (for example, a thin film made of carbon) having a specific atom or element composition on a substrate such as a template. Normally, when a gas containing a raw material is given energy by heat or light, or plasma is generated at a high frequency, a chemical reaction or thermal decomposition occurs, and the raw material is radicalized. In this way, the raw material becomes rich in reactivity, and is a technique that utilizes adsorption and deposition on the substrate. When the temperature is increased and the source material is deposited is called a thermal CVD method, the one that irradiates light to promote chemical reaction or thermal decomposition is called the photo CVD method, and the method that excites the gas into the plasma state is called the plasma CVD method. There is also.

The organic compound to be introduced is preferably a nitrogen-containing compound such as acetonitrile, for example, and nitrogen is deposited on the carbon skeleton of the porous material by introducing the nitrogen-containing organic compound and performing vapor phase carbonization. be able to. The organic compound containing nitrogen can be used as a mixture with a gaseous organic compound at room temperature or an organic compound that can be easily vaporized, if necessary. As such an organic compound, for example, methane, ethane, propane, ethylene, propylene, isoprene, benzene, vinylbenzene and the like can be used. The vaporized nitrogen-containing organic compound is heated while being circulated so as to be in contact with the porous material together with the carrier gas. By doing so, it is possible to easily deposit nitrogen on carbon in the gas phase. In nitrogen doping, it is preferable that the obtained microporous carbon-based material has a larger value with respect to hydrophilicity, conductivity, and dielectric constant. The type, flow rate, flow rate, and heating temperature of the carrier gas need to be adjusted as appropriate depending on the type of organic compound and porous material used. Examples of the carrier gas to be used include N ₂ gas, helium, neon, and argon, but a mixture with oxygen gas or hydrogen gas can also be used.

  The porous material used as a template when synthesizing the microporous carbon-based material according to the embodiment of the present invention can introduce an organic compound into the pores, and has an original structure when carbonizing the organic compound. It is necessary to keep it stable and to be separable from the produced microporous carbon-based material. For this reason, what is excellent in heat resistance and melt | dissolves in an acid and an alkali is preferable, and a porous oxide can be used. Further, the obtained microporous carbon-based material has a structure that reflects the shape of the pores of the mold, a connection mode of the holes, and a hole that reflects the shape of the mold itself. In other words, the microporous carbon material is synthesized with the form of the template transferred. For this reason, it is desirable that the porous material of the template is a material with a sufficiently developed crystal and uniform particle size and uniform structure and composition.

As described above, considering the material properties of the porous material of the template and the physical properties of the resulting microporous carbon material, it is preferable to use zeolite as the porous material to be the template. Zeolite is an aluminosilicate in which a part of silicon (Si) in a silica structure is substituted with aluminum (Al), and the skeleton itself has a negative charge, and thus has a structure in which cations are distributed in the structure. Zeolite has various crystal structures depending on the Si / Al molar ratio, the type and amount of the cation, and the number of water molecules hydrated to the cation. In addition, for example, there are holes of various sizes such as a structure in which holes are two-dimensionally connected or a structure in which holes are three-dimensionally connected. The zeolite is particularly preferably a zeolite having a 12-membered ring or more. The zeolite is preferably FAU type zeolite, and more preferably Y type zeolite. As will be described later, the zeolite is more preferably an ammonium ion (NH ₄ ⁺ ) exchanged zeolite. In this case, it is possible to increase the nitrogen content in the obtained microporous carbon material. Any method may be used to remove the porous material used as the template as long as the produced microporous carbon-based material can be separated. For example, the above-mentioned zeolite can be dissolved with an acid, and specifically, easily dissolved by using hydrochloric acid or hydrofluoric acid.

  The microporous carbon material according to the embodiment of the present invention can be obtained by using a porous material containing nitrogen as a template, separately from the method of introducing an organic compound containing nitrogen into the porous material described above. be able to. In this case, even if an organic compound containing nitrogen is not used as a nitrogen source, the obtained microporous carbon material has a structure containing desired nitrogen. That is, the microporous carbon material according to the embodiment of the present invention introduces the first organic compound into the surface of the porous material containing nitrogen and the inside of the pores, and heats the first organic compound. A first step of carbonizing, a second step of introducing a second organic compound separately from the first organic compound into the surface of the porous material and inside the pores, and vapor-phase carbonizing, and a porous material And a third step to be removed.

In this case, the nitrogen-containing porous material is preferably an ammonium ion (NH ₄ ⁺ ) exchanged zeolite. In this case, the microporous carbon material containing nitrogen according to the embodiment of the present invention can be easily obtained. In the case of using ammonium ion (NH ₄ ⁺ ) -exchanged zeolite, ion-exchanged NH ₄ ⁺ is introduced as a nitrogen source, and therefore it is not always necessary to use an organic compound containing nitrogen as the nitrogen source. In addition, it is preferable that the 1st and 2nd organic compound introduce | transduced into the porous material containing nitrogen can be easily vaporized, and as mentioned above, the organic compound containing nitrogen may be sufficient. When an organic compound containing nitrogen is used, the nitrogen content can be increased.

  Moreover, it is preferable that the 1st and 2nd organic compound introduce | transduced into a porous material uses the compound which superposes | polymerizes by heat-processing. Examples of the compound not containing nitrogen include compounds containing a heterocycle having an oxygen atom as a heteroatom, such as an alcohol derivative. Examples thereof include compounds having a polymerizable unsaturated group such as a vinyl group-containing alcohol derivative. Examples thereof include aromatic or heterocyclic aldehydes such as phenol aldehyde and furfural, and mixtures thereof. For example, furfuryl alcohol and vinyl acetate are preferably used. A mixture of an organic compound containing nitrogen and an organic compound not containing nitrogen may be used.

  For removing the porous material, any method may be used as long as the produced porous carbon material can be separated. For example, when zeolite is used, it can be dissolved with an acid. Specifically, it can be easily dissolved and removed by using hydrochloric acid or hydrofluoric acid.

  One preferred embodiment of the method for producing the microporous carbon-based material described above will be given. First, as a first step, for example, an organic compound containing nitrogen such as 4,6-dihydroxypyrimidine is introduced into the zeolite pores, and this is heated and polymerized. Then, it carbonizes by heating at the temperature of 600-900 degreeC. Next, as a second step, for example, a gaseous nitrogen-containing organic compound such as acetonitrile is introduced, and this is heated at 600 to 1000 ° C. to perform chemical vapor deposition. Carbides generated in the first step Nitrogen adheres to the cavities or surfaces. Next, as a third step, the zeolite is dissolved and removed. By this method, a desired microporous carbon-based material can be obtained. As needed, you may heat-process at a temperature higher than a 2nd process, ie, 800-1000 degreeC, before a 3rd process.

As another preferred embodiment, for example, by introducing a liquid organic compound such as furfuryl alcohol inside the zeolite pores and ammonium ion (NH 4 ^₊₎ exchange, it is polymerized by heating it. Then, it carbonizes by heating at the temperature of 600-900 degreeC. Next, as a second step, for example, a gaseous organic compound such as acetylene is introduced, and this is heated at 600 to 1000 ° C. to perform chemical vapor deposition, and the carbide cavities generated in the first step Alternatively, nitrogen is attached to the surface. Next, as a third step, the zeolite is dissolved and removed. By this method, a desired microporous carbon-based material can be obtained.

  The microporous carbon-based material carrying the transition metal according to the embodiment of the present invention is obtained by immersing and impregnating the microporous carbon-based material obtained in the third step of removing the porous material in the transition metal salt solution. Then, it can be obtained by a method of carrying out liquid phase reduction and supporting a transition metal on the micropore surface.

  A method for supporting a transition metal on the micropore surface by liquid phase reduction will be described. The method of supporting the transition metal includes a dipping step of immersing and impregnating the microporous carbon-based material obtained in the third step of removing the porous material in a transition metal salt solution to obtain a mixed solution, and this mixed solution. After stirring under reduced pressure, the separation step of separating the microporous carbon-based material adsorbed with the transition metal by centrifugation is mixed with the microporous carbon-based material adsorbed by the separation metal and the reducing agent solution. A liquid phase reduction process in which the adsorbed transition metal is liquid phase reduced and deposited on the surface and micropores of the microporous carbon material, and the microporous carbon material on which the transition metal is deposited is washed with pure water. And a drying step for drying. By this liquid phase reduction, the transition metal adsorbed on the microporous carbon material can be reduced and deposited.

  The transition metal salt solution is preferably prepared in a range of 10 ppm to 5 wt%. When the concentration is 10 ppm or less, the effect of supporting the transition metal cannot be obtained. On the other hand, when the concentration is 5 wt% or more, the amount of the transition metal supported is too much to reduce the BET surface area, and as a result, the microporous carbon material has a pore function before supporting the transition metal. Is damaged.

  As the solvent for dissolving the transition metal salt, it is desirable to use a solvent having a boiling point of 100 ° C. or lower at normal pressure in consideration of desolvation and drying in the subsequent steps. In consideration of the solubility of the metal salt, water, alcohol, acetone, ether (chain ether or cyclic ether), etc. are preferably used, and can be used as a mixed solvent in which these are mixed. It is.

  In the method for reducing the attached metal ions, it is preferable that the reducing agent is dissolved in a solvent and the reducing agent solution contains a hydride complex. The hydride complex preferably includes any one of sodium borohydride, lithium borohydride, sodium cyanoborohydride, zinc borohydride, and sodium acetoxyborohydride, and may include two or more types. .

  The solvent to be used is a solvent that does not affect the supported transition metal such as oxidation, and is preferably a solvent that is not reduced by the reducing agent. When platinum is used as the transition metal to be supported, it can be used as water, alcohol, ether, or a mixed solvent in which these are mixed. When using lanthanoids such as titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zirconium, molybdenum, ruthenium, rhodium, palladium and lanthanum, cerium as the transition metal, oxidation of the metal during solvent drying It is preferable to use a more inert solvent in order to prevent this, and it is preferable to use a primary alcohol or ether as the solvent.

  Carbon materials that are not nitrogen-doped, including activated carbon and microporous carbon-based materials, are highly hydrophobic, but the polarity of the microporous carbon-based material 2 according to the embodiment of the present invention that is doped with nitrogen is improved. Since it is hydrophilic, dispersibility is improved when a transition metal is supported. FIG. 3 shows an image diagram in which a transition metal is coordinated with a microporous carbon material. The microporous carbon material 11 shown in FIG. 3 indicates that the transition metal 14 is coordinated to the nitrogen atom 13 of the nitrogen-containing organic compound 12. It is considered that the transition metal 14 can be supported not only as metal nanoparticles but also at the atomic level as shown in FIG. Thus, according to the method for producing a microporous carbon material according to the embodiment of the present invention, it can be expected that the transition metal 14 is coordinated to the nitrogen atom 13 at the atomic level.

  Hereinafter, the production method of the microporous carbon material and the microporous carbon material according to the embodiment of the present invention will be described more specifically by Examples 1 to 7 and Comparative Examples 1 to 6, but the scope of the present invention is as follows. It is not limited to these.

1. Sample Preparation <Example 1: NaY-DHP-H7 (2) -AN8.5 (2) -H9 (1)>
A 6.5% 4,6-dihydroxypyrimidine (DHP) / ethylenediamine solution was added to the dried Y-type zeolite (NaY5.5) and impregnated. Y type zeolite HSZ-300 series: 341NHA manufactured by Tosoh was used as the Y type zeolite. After impregnation, it was evaporated to dryness at 60 ° C. The resulting mixture was held at 125 ° C. for 2 h under N ₂ atmosphere. Thereafter, heat treatment was performed at 380 ° C. for 2 hours. Since the melting point of DHP is 300 ° C., the DHP penetrated into the zeolite pores in a liquefied state by this heat treatment. The mixture after the heat treatment was repeatedly washed with ethylenediamine to remove DHP existing outside the particles. Then, the temperature was raised to 700 ° C. in _{a N 2} atmosphere, 2h and held at this temperature to obtain the carbon / zeolite composite NaY-DHP-H7 (2) . Next, NaY-DHP-H7 (2) was once cooled to room temperature, then heated to 850 ° C. in an N ₂ atmosphere, and acetonitrile CVD was performed at 850 ° C. for 2 hours. Furthermore, the temperature was raised to 900 ° C. at 5 ° C./min in an N ₂ atmosphere and maintained for 1 hour to prepare a carbon / zeolite composite. Finally, this was added to 100 ml of 47 wt% hydrofluoric acid and stirred for 5 hours to take out the microporous carbon-based material. The sample thus obtained was named NaY-DHP-H7 (2) -AN8.5 (2) -H9 (1). An is acetonitrile, and 8.5 in An 8.5 (2) indicates that the CVD temperature is 850 ° C., and (2) indicates that the CVD time is 2 h. H in H9 (1) means heat treatment after CVD, 9 indicates that the temperature is 900 ° C., and (1) indicates that the heat treatment time is 1 h. In the following, this nomenclature will be used for samples obtained under other synthesis conditions.

<Example 2: NaY-DHP-H7 (2) -AN8 (2) -H9 (3)>
The carbon / zeolite composite NaY-DHP-H7 (2) obtained by the same treatment as in Example 1 was once cooled to room temperature, then heated to 800 ° C. in an N ₂ atmosphere, and kept at 800 ° C. for 2 hours with acetonitrile CVD. Went. Further, the temperature was raised to 900 ° C. at 5 ° C./min in an N ₂ atmosphere and held for 3 hours to prepare a carbon / zeolite composite. Finally, this was added to 100 ml of 47 wt% hydrofluoric acid and stirred for 5 hours to take out the microporous carbon-based material. The sample thus obtained was named NaY-DHP-H7 (2) -AN8 (2) -H9 (3).

<Example ^{_{3: NH 4 + Y-DHP}} -AN8 (2) -H9 (1)>
In the same manner as in Example 1, DHP was permeated into the zeolite pores to obtain a mixture. The mixture after the heat treatment was repeatedly washed with ethylenediamine to remove DHP existing outside the particles. The zeolite used was one obtained by exchanging Na with NH ₄ ⁺ by ion exchange. Next, without performing the heat treatment at 700 ° C. in an _{N 2} atmosphere, the temperature was raised to 800 ° C. in _{a N 2} atmosphere was 2h acetonitrile CVD as is 800 ° C.. Furthermore, the temperature was raised to 900 ° C. at 5 ° C./min in an N ₂ atmosphere and maintained for 1 hour to prepare a carbon / zeolite composite. Finally, after adding this to 00 ml of 47 wt% hydrofluoric acid, it stirred for 5 hours and processed, and the microporous carbon material was taken out. The obtained sample was thus with ^{_{NH 4 + Y-DHP-AN8}} (2) -H9 (1).

<Example ^{_{4: NH 4 + Y-DHP}} -AN8 (2) -H9 (3)>
It was carried out in the same manner as in Example 3 except that the holding time after heating after carrying out acetonitrile CVD at 800 ° C. was 3 h. The sample thus obtained was named NH ₄ ⁺ Y-DHP-AN8 (2) -H9 (3).

<Example ^{_{5: NH 4 + Y-PFA}} -AN8.5 (2) -H9 (1)>
Dry NH ₄ ⁺ Y zeolite (Y-type zeolite HSZ-300 series manufactured by Tosoh: 341NHA, SiO ₂ / Al ₂ O ₃ ratio = 7.0) was impregnated with furfuryl alcohol (FA). Then, it heat-processed at 150 degreeC for 8 hours, FA was polymerized, and it was set as the polyfurfuryl alcohol (PFA) / zeolite composite. This was heated up to 800 ° C. at 5 ° C./min under N ₂ atmosphere. Next, acetonitrile CVD was performed at 850 ° C. for 2 h. Thereafter, the temperature was raised to 900 ° C. at 5 ° C./min in an N ₂ atmosphere and maintained for 1 hour to prepare a carbon / zeolite composite. Finally, this composite was put into 100 ml of 47 wt% hydrofluoric acid, stirred for 5 hours and treated with hydrofluoric acid, and the zeolite as a template was dissolved and removed to take out a microporous carbon material. The sample thus obtained was named NH ₄ ⁺ Y-PFA-AN 8.5 (2) -H9 (1).

<Example ^{_{6: NH 4 + Y-PFA}} -AN8 (2) -H9 (1)>
The same procedure as in Example 5 was performed except that acetonitrile CVD was performed at 800 ° C. The sample thus obtained was named NH ₄ ⁺ Y-PFA-AN8 (2) -H9 (1).

<Example 7: N-ZTC / Pt-0.8%>
Example 7 shows an example in which platinum is supported by liquid phase reduction. The MPC used for platinum loading is NH ₄ ⁺ Y-DHP-AN8 (2) -H9 (3) having a surface area of 2080 m ² / g prepared in Example 4. 4.54 wt% of [Pt (NH ₃ ) ₂ (NO ₂ ) ₂ ] / HNO ₃ aqueous solution 5 mg diluted with 2.0 g of pure water and 2.4 mg of NaBH 4 diluted with 20 ml of pure water Solution B was prepared, and solutions A and B were cooled to 0 ° C. The concentrations of the solutions A and B were calculated so that the supported amount of platinum was 0.8 wt% with respect to MPC. Next, 30 mg of MPC was added to the solution A at 0 ° C., and stirred at 0 ° C. for 30 minutes in a reduced pressure atmosphere. Next, the MPC was centrifuged, mixed with the solution B at 0 ° C., and stirred at 0 ° C. for 10 minutes to reduce Pt (NH ₃ ) ₂ (NO ₂ ) ₂ to generate platinum nanoparticles. Finally, the operation of filtering the MPC supporting platinum nanoparticles and washing with pure water was repeated several times, and then vacuum drying was performed at 150 ° C. for 6 hours, whereby the MPC supporting the platinum (sample N-ZTC) was supported. /Pt-0.8%).

<Comparative Example 1: NaY-PFA-P7 (1) -H9 (3)>
The dried zeolite (NaY5.5) was impregnated with furfuryl alcohol (FA). This was heat-treated at 150 ° C. for 8 hours to polymerize FA to obtain a PFA / zeolite composite. This was heated to 850 ° C. at 5 ° C./min in an N ₂ atmosphere, and then 1 h propylene CVD was performed at 700 ° C. Thereafter, the temperature was raised to 900 ° C. at 5 ° C./min in an N ₂ atmosphere and maintained for 3 hours to prepare a carbon / zeolite composite. Finally, the composite was put into 100 ml of 47 wt% hydrofluoric acid, stirred for 5 hours and treated with hydrofluoric acid, and the zeolite as a template was dissolved and removed to take out a microporous carbon material (MPC). . The sample thus obtained was named NaY-PFA-P7 (1) -H9 (3).

<Comparative Example 2: NaY-PFA-AN8.5 (2) -H9 (1)>
The dried zeolite (NaY5.5) was impregnated with furfuryl alcohol (FA). This was heat-treated at 150 ° C. for 8 hours to polymerize FA to obtain a PFA / zeolite composite. This was heated to 850 ° C. at 5 ° C./min in an N ₂ atmosphere, and then acetonitrile CVD was performed at 850 ° C. for 2 h. Thereafter, the temperature was raised to 900 ° C. at 5 ° C./min in an N ₂ atmosphere and maintained for 1 hour to prepare a carbon / zeolite composite. Finally, the composite was put into 100 ml of 47 wt% hydrofluoric acid, stirred for 5 hours and treated with hydrofluoric acid, and the zeolite as a template was dissolved and removed to obtain a microporous carbon material (conventional nitrogen-doped MPC). Was taken out. The sample thus obtained was named NaY-PFA-AN8.5 (2) -H9 (1).

<Comparative Example 3: NaY-DHP>
In the same manner as in Example 1, DHP was permeated into the zeolite pores to obtain a mixture. The mixture after heat treatment at 380 ° C. was repeatedly washed with ethylenediamine to remove DHP present outside the particles. Next, this composite was put into 100 ml of 47 wt% hydrofluoric acid, stirred for 5 hours and treated with hydrofluoric acid, and the zeolite as a template was dissolved and removed to take out a microporous carbon material. The sample thus obtained was designated as NaY-DHP.

<Comparative Example 4: NaY-DHP-H7 (2)>
A 6.5% 4,6-dihydroxypyrimidine (DHP) / ethylenediamine solution was added to the dried Y-type zeolite (NaY5.5) and impregnated. After impregnation, it was evaporated to dryness at 60 ° C. The resulting mixture was held at 125 ° C. for 2 h under N ₂ atmosphere. Thereafter, heat treatment was performed at 380 ° C. for 2 hours. Since the melting point of DHP is 300 ° C., the DHP penetrated into the zeolite pores in a liquefied state by this heat treatment. The mixture after the heat treatment was repeatedly washed with ethylenediamine to remove DHP existing outside the particles. Then, the temperature was raised to 700 ° C. in _{a N 2} atmosphere, 2h and held at this temperature to obtain the carbon / zeolite composite NaY-DHP-H7 (2) . Finally, this composite was put into 100 ml of 47 wt% hydrofluoric acid, stirred for 5 hours and treated with hydrofluoric acid, and the zeolite as a template was dissolved and removed to take out a microporous carbon material. The sample thus obtained was named NaY-DHP-H7 (2).

<Comparative Example ^{_{5: NH 4 + Y-DHP}} >
DHP was permeated into the zeolite pores by the same treatment as in Example 3 to obtain a mixture. The mixture after heat treatment at 380 ° C. was repeatedly washed with ethylenediamine to remove DHP present outside the particles. Next, this composite was put into 100 ml of 47 wt% hydrofluoric acid, stirred for 5 hours and treated with hydrofluoric acid, and the zeolite as a template was dissolved and removed to take out a microporous carbon material. The obtained sample was thus with _NH ⁴ + Y-DHP.

2. Evaluation Powder X-ray diffraction measurement of microporous carbon materials synthesized in Examples and Comparative Examples was performed using XRD-6100 manufactured by Shimadzu Corporation, and the radiation source was Cu-Kα, voltage 30 kV, and current 20 mA. XPS was performed using PHI 5600 manufactured by Perkin-Elmer, and the radiation source was Mg-Kα, voltage 8 kV, current 30 mA. The BET surface area was measured using BELSORP mini manufactured by Nippon Bell Co., Ltd., and a multipoint method was performed at a temperature of −196 ° C. The water vapor adsorption isotherm was measured at a temperature of 25 ° C. using BELSORP MAX manufactured by Nippon Bell.

  Powder showing the type of cation of zeolite of microporous carbon-based material synthesized in Examples and Comparative Examples, carbon precursor of obtained sample, BET surface area, nitrogen content (N / C) and presence of long-period ordered structure The results measured using an X-ray diffractometer (XRD) are summarized in the table shown in FIG. In FIG. 4, XRD indicates the intensity of the peak around 2θ = 6.4 ° in the X-ray diffraction pattern.

As shown in Examples 1 to 4 and Comparative Examples 3 to 5, it can be seen that the nitrogen content is increased by using DHP instead of PFA as the carbon precursor. Moreover, as shown in Example 5 and Comparative Example 2, it can be seen that when the cation type of the zeolite is NH ₄ ⁺ , a sample having a high nitrogen content can be obtained. In particular, as shown in Examples 3 and 4, when the carbon precursor is DHP and the cation type of the zeolite is NH ₄ ⁺ , the nitrogen content is high. Among the nitrogen-doped MPCs obtained this time, NH ₄ ⁺ Y-DHP-An8 (2) -H9 (1) obtained in Example 3 has the highest nitrogen content, and N / C is 0.00. 09. N / C of the conventional nitrogen-doped MPCNaY-PFA-An8.5 (2) -H9 (1) shown in Comparative Example 2 is 0.058, and the maximum N / C is about 1. It could be increased up to 6 times.

In each example, the BET surface area was as high as 2000 m ² / g or more. On the other hand, in Comparative Examples 3 to 5, although the nitrogen content was high, the BET surface area was low. Thus, it was found that the surface area cannot be increased unless chemical vapor deposition is performed as the second step in preparing the sample.

  As shown in FIGS. 4 and 7, in Examples 1, 2, and 5, the X-ray diffraction pattern has a large peak intensity indicating a long-period regular structure near 2θ = 6 ° indicated by 7X, and is indicated by 7Y. The intensity of the peak derived from the lamination of the carbon network surface at 2θ = 20 to 30 ° was small. From this, the obtained sample retains the regular structure of MPC. This suggests that when CVD was performed, carbon was not deposited on the outer surface of the zeolite particles but was deposited in the micropores of the zeolite.

Next, FIG. 5 shows the presence of nitrogen in each sample analyzed by XPS. From comparison between Example 6 and Comparative Example 2, it can be seen that when the cation of the zeolite is changed from Na ⁺ to NH ₄ ⁺ , not only the nitrogen content is increased, but also pyridine nitrogen is increased. That is, it can be seen that NH ₄ ⁺ existing as a cation of the zeolite is mainly incorporated into the carbon skeleton as pyridine nitrogen. In Example 3, the ratio of nitro groups is small. This shows that when DHP is used as the carbon precursor, NH ₄ ⁺ which is a cation of the zeolite is incorporated into the carbon skeleton not only as pyridine nitrogen but also as quaternary nitrogen.

In FIG. 5, when NH ₄ ⁺ Y is used instead of NaY for zeolite, pyridine type nitrogen tends to increase. Further, when DHA is used instead of PFA, quaternary nitrogen tends to increase.

In FIG. 4, in Example 4, N / C remained as high as 0.084 even though the heat treatment was performed for 3 hours. This is probably because the ratio is the largest. As described above, when nitrogen-doped MPC is synthesized using DHP as a raw material and a zeolite whose cation is NH ₄ ⁺ as a template, it is understood that nitrogen-doped MPC can be synthesized in which the nitrogen content is less likely to decrease even when treated at high temperature for a long time. It was. In general, when preparing nitrogen-containing carbon from a nitrogen-containing polymer, the sample is heat-treated at a temperature around 300 to 600 ° C. to stabilize the structure, and then carbonized at 800 ° C. or higher to perform nitrogen content. Increase. Also in the embodiment of the present invention, the nitrogen content may be further increased by appropriately performing heat treatment in the same manner.

  Next, the water vapor adsorption isotherm of the nitrogen-doped MPC is shown in FIG. Compared with the comparative example 1 in which N / C is 0, the rapid increase in water vapor is observed near the relative pressure of 0.5, but in the example 3 containing nitrogen, the comparative examples 1 and 2, etc., the relative pressure It turns out that it stands up around 0.4. When the pore diameter is the same, the smaller the relative pressure at which the amount of adsorption increases rapidly, the more hydrophilic the material surface. FIG. 6 shows that the relative pressure of Example 3 with the highest N / C is shifted to the lowest pressure side, so that MPC with a higher nitrogen content has higher hydrophilicity. That is, it is considered that the polarity of the surface of the material has increased due to the nitrogen content.

[Evaluation of hydrogen storage capacity]
About the sample of the Example, the pressure-composition isotherm (PCT line) was obtained according to the Siebert method (capacity method, JIS H 7201). The hydrogen storage capacity was measured using a compression coefficient determined by the National Institute of Standards and Technology (NIST). The measurement accuracy depends on the filling amount of the sample. At least 1 g or more was charged, and the above synthesis scheme was repeated as necessary to prepare the required amount. The sample was weighed and placed in a pressure-resistant sample tube for measurement, and was evacuated at 100 ° C. for 4 hours to release the gas remaining in the sample tube, and measurement was performed after obtaining an origin where hydrogen was not occluded. The measurement temperature was 30 ° C. and 100 ° C. Thereafter, the pressure was reduced to atmospheric pressure, and the hydrogen release amount was confirmed.

The measurement results are shown in FIGS. FIG. 8 is a graph showing the hydrogen storage capacity of Examples 4 and 7 at 30 ° C., and FIG. 9 is a graph showing the hydrogen storage capacity of Examples 4 and 7 at 100 ° C. According to the hydrogen storage amount at 30 ° C. shown in FIG. 8 (PCT diagram), the hydrogen storage amount at hydrogen equilibrium pressure of 10.5 MPa of Example 4 shown by 8A and Example 7 shown by 8B is 0.64 wt%, It was 0.70 wt%. The BET surface area of Example 7 supporting platinum was 1780 m ² / g, and the BET surface area of Example 4 not supporting platinum was 2080 m ² / g. Thus, although Example 7 has a larger hydrogen storage amount than Example 4, the hydrogen storage amount is different from that of conventional examples, such as hydrogen dissociation adsorption by platinum such as spillover due to platinum loading. Is considered working. Moreover, according to the hydrogen storage amount (PCT diagram) at 100 ° C. shown in FIG. 9, the hydrogen storage amount at hydrogen equilibrium pressure of 10.5 MPa in Example 4 shown in 9A and Example 7 shown in 9B is 0.41 wt. %, 0.77 wt%. Even at 100 ° C., Example 7 supporting platinum had a higher hydrogen storage capacity than Example 4 not supporting platinum. In Example 4, the amount of hydrogen occlusion decreased as the temperature increased. In Example 7, which carried platinum, the amount of hydrogen occlusion increased as the temperature increased. Thus, it was suggested that by supporting platinum, the temperature dependency of the hydrogen storage capacity was improved, and the hydrogen storage capacity was improved as the temperature increased.

According to the present invention, in a microporous carbon-based material doped with nitrogen of 0.07 or more in N / C element ratio while maintaining a BET surface area of 1500 m ² / g or more, the nitrogen doping amount is improved and hydrophilicity is increased. It became clear that it improved. By using zeolite as a template, the microporous carbon-based material that has nano-level structural regularity and porosity, and also exhibits an excellent function by nitrogen doping, is water vapor, oxygen-containing hydrocarbon compound, hydrogen, It is expected to be applied to a material that stores gas used as fuel represented by methane. Also applied to matrix materials of new composite materials, electrically conductive materials, carbon membranes, electrode materials such as capacitors, lithium ion batteries, and fuel cells, which are devices that convert electrical energy into chemical energy for storage, and new composites Application to a matrix of materials, an electrically conductive material, a carbon film, and an adsorption heat pump is expected. The ability to synthesize such a carbon material is beneficial in that it has the potential to broaden the range of material choices in various industries and dramatically improve the performance of products.

  In addition, according to the present invention, the microporous carbon material in which the transition metal is supported on the micropore surface can exhibit the function of the supported metal while maintaining the inherent pore function. I understood. As described above, application in various fields can be expected by supporting the transition metal.

  It will be apparent that the invention may be practiced otherwise than as particularly described in the foregoing description and examples. Many modifications and variations of the present invention are possible in light of the above teachings, and thus are within the scope of the claims appended hereto.

1 Porous material 1a Micropore (hole)
2 Microporous carbon-based material 2a Long-period regular structure 2b Micropore 3 Composite 4 Transition metal 5 Microporous carbon-based material

Claims (10)

A nitrogen-containing organic compound selected from substituted or unsubstituted imidazole, oxazole, pyrazole, triazole, pyridazine, pyrimidine, pyrazine, triazine, and tetrazine compounds is introduced into the surface of the porous material and the pores, and the nitrogen A first step of heating and carbonizing the containing organic compound;
After the carbonization, a second step of introducing an organic compound into the surface of the porous material and the inside of the pores to vapor-phase carbonize;
And a third step of removing the porous material after the vapor phase carbonization. A method for producing a microporous carbon material, comprising: The method for producing a microporous carbon material according to claim 1, wherein the nitrogen-containing organic compound is selected from substituted or unsubstituted pyrimidine compounds. The method for producing a microporous carbon material according to claim 1 or 2, wherein the porous material contains nitrogen. Further, an immersion step of immersing and impregnating the microporous carbon material obtained in the third step of removing the porous material in a transition metal salt solution to obtain a mixed solution;
A separation step of separating the microporous carbon-based material adsorbed with the transition metal by centrifugation after stirring the mixture under reduced pressure;
A liquid phase in which the microporous carbon-based material adsorbed with the transition metal obtained by the separation and the reducing agent solution are mixed, and the adsorbed transition metal is liquid-phase reduced to precipitate on the surface of the microporous carbon-based material and in the micropores. A reduction process;
The microporous carbon-based material according to any one of claims 1 to 3 , further comprising a drying step of washing the microporous carbon-based material on which the transition metal is deposited with pure water and drying the material. Material manufacturing method. A first step of introducing a nitrogen-containing organic compound into the surface of the porous material and inside the pores, and heating and carbonizing the nitrogen-containing organic compound;
After the carbonization, a second step of introducing an organic compound into the surface of the porous material and the inside of the pores to vapor-phase carbonize;
A third step of removing the porous material after the vapor phase carbonization, and a method for producing a microporous carbon material,
Further, an immersion step of immersing and impregnating the microporous carbon material obtained in the third step of removing the porous material in a transition metal salt solution to obtain a mixed solution;
A separation step of separating the microporous carbon-based material adsorbed with the transition metal by centrifugation after stirring the mixture under reduced pressure;
A liquid phase in which the microporous carbon-based material adsorbed with the transition metal obtained by the separation and the reducing agent solution are mixed, and the adsorbed transition metal is liquid-phase reduced to precipitate on the surface of the microporous carbon-based material and in the micropores. A reduction process;
Method of manufacturing features and to Rumi black porous carbon-based material that has a microporous carbon-based material to precipitate transition metal and drying step of drying washed with pure water.   The method for producing a microporous carbon material according to claim 5, wherein the reducing agent solution contains a hydride complex.   The hydride complex includes any one of sodium borohydride, lithium borohydride, sodium cyanoborohydride, zinc borohydride, and sodium acetoxyborohydride. A method for producing a microporous carbon-based material.   The microporous carbon according to any one of claims 5 to 7, wherein the solvent used in the transition metal salt solution and / or the solvent used in the reducing agent solution contains a primary alcohol or an ether. A method for manufacturing a system material.   The method for producing a microporous carbon material according to any one of claims 1 to 8, wherein the porous material is zeolite.   The method for producing a microporous carbon material according to claim 9, wherein the zeolite is a zeolite ion exchanged with ammonium ions (NH4 +).