JP2011083755A - Porous organometallic complex for gas occlusion, gas storage method and gas storage device using the same, and fuel cell system using the gas storage device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a porous organometallic complex for gas occlusion including an aromatic heterocyclic compound containing a nitrogen atom capable of being coordinated at least on two sites, and having enough gas occlusion capacity. <P>SOLUTION: The porous organometallic complex for gas occlusion is constituted by a coordinate bond of [1] metal ions [2] dicarboxylic acid compound (ligand) and [3] an aromatic heterocyclic compound containing a nitrogen atom capable of being coordinated at least on two sites with the metal ion. [1] There's no particular limitations as metal ions, and ions such as Mg, Al, Ca, Ti, Mn, Fe, Co, Ni, Cu, Zn and the like can be named. Favorably, a Cu ion is preferable. Also, [2] as dicarboxylic acid compound, an aromatic dicarboxylic acid represented by formulas (1) to (6) (formulas (2) to (6) are not shown) is preferable. Furthermore, [3] as an aromatic heterocyclic compound containing a nitrogen atom capable of being coordinated at least on two sites with the metal ion, those represented by formulas (7) to (15) (formulas (8) to (15) are not shown) can be used. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a gas-storing porous organometallic complex that can store various gases, a gas storage method and gas storage device using the same, and a fuel cell system that uses hydrogen stored in the gas storage device. In particular, the present invention relates to a porous organometallic complex for gas occlusion that can easily occlude / hold gas under pressure and release the gas by depressurization, a gas storage method and gas storage device using the same, and The present invention relates to a fuel cell system in which hydrogen is stored in this gas storage device.

  Porous metal organic complexes are attracting attention as new porous bodies comparable to activated carbon and zeolite (see Non-Patent Document 1). This porous organometallic complex is a solid substance group composed of a metal and an organic bridging ligand, and is also called a coordination polymer or an integrated metal complex. In the porous metal-organic complex, the size and shape of the pores in the crystal structure can be easily changed by changing the size and shape of the ligand. In addition, many functions such as gas adsorption, ion exchange, catalytic field, or polymer synthesis have been studied in previous studies.

"Organic storage materials and nanotechnology-Toward a hydrogen society", supervised by Masaru Ichikawa, CM Publishing, 2007

  Many examples of such porous organometallic complexes containing an aromatic heterocyclic compound containing a nitrogen atom have been reported so far. In particular, it has been found that an aromatic heterocyclic compound containing a nitrogen atom capable of coordinating two or more can stably form a porous organometallic complex.

  Recently, hydrogen gas as clean energy, which can be used as fuel for fuel cells, has been attracting attention. It is desired that this hydrogen gas can be stored easily and safely and can be stably supplied, and the use of porous organometallic complexes containing aromatic heterocyclic compounds for hydrogen gas storage has been studied. The structure of an aromatic heterocyclic compound optimal for hydrogen storage having a sufficient gas storage capacity has not been clarified.

  Furthermore, when gas is stored in the porous organometallic complex, the gas to be stored is stored under pressure in the porous organometallic complex filled in the pressure vessel, but it is included in the gas by repeated use. There was a problem that the porous metal-organic complex adsorbed a slight amount of water, and the gas storage rate was lowered.

  The present invention has been made in view of the above problems, and includes an aromatic heterocyclic compound containing a nitrogen atom that can coordinate bidentate or more, and a porous organometallic complex for gas storage having sufficient gas storage capability. The purpose is to provide. Another object of the present invention is to provide a gas storage method and gas storage device using such a porous organometallic complex for gas storage. Furthermore, an object of the present invention is to provide a fuel cell system that supplies hydrogen gas using this gas storage device.

  In order to solve the above-mentioned problems, first, the present invention provides a coordinate bond between a metal ion, a dicarboxylic acid compound, and an aromatic heterocyclic compound containing a nitrogen atom to which the metal ion can coordinate in two or more positions. And a porous organometallic complex for gas storage, characterized by having a pore structure (claim 1).

  A porous organometallic complex for gas storage according to the above invention (invention 1) includes a plurality of layered lattices of metal ions and dicarboxylic acid compounds, and aromatics containing nitrogen atoms capable of coordinating two or more of the metal ions. It has a three-dimensional lattice structure in which heterocyclic compounds are linked. In this three-dimensional lattice structure, by applying a predetermined pressure, gas molecules such as hydrogen molecules are caused to intercalate with the aromatic heterocyclic compound or dicarboxylic acid compound constituting the three-dimensional lattice. It can be stably held inside, and is suitable for gas storage. Furthermore, since the intermolecular force described above is weak, the retained gas molecules can be released by reducing the pressure.

In the said invention (invention 1), it is preferable that the specific surface area measured value by BET method of this porous organometallic complex for gas storage is 20 m < ² > / g or more (invention 2).

  According to the above invention (invention 2), since the specific surface area of the porous organometallic complex has a certain degree of correlation with the number of three-dimensional lattice structures, it is possible to secure a certain amount of occlusion of gas molecules. Become.

  In the above inventions (Inventions 1 and 2), the metal ion is preferably a metal ion selected from the group consisting of magnesium, aluminum, calcium, titanium, manganese, iron, cobalt, nickel, copper, and zinc. (Claim 3).

  According to the said invention (invention 3), the aromatic heterocyclic compound containing the dicarboxylic acid compound and the nitrogen atom which can be coordinated 2 or more, and a three-dimensional porous organometallic complex can be formed suitably.

  In the said invention (Invention 1-3), it is preferable that the said dicarboxylic acid compound is aromatic dicarboxylic acid (Invention 4).

  According to this invention (Invention 4), the aromatic dicarboxylic acid forms a layered lattice with a metal ion, and further includes an aromatic heterocyclic compound containing a nitrogen atom capable of coordinating two or more positions and a three-dimensional porous organic compound. A metal complex can be suitably formed, and an intermolecular force with gas molecules can be applied.

  Secondly, the present invention fills a pressure vessel with the powder of the porous metal-organic complex for gas storage according to the above inventions (Inventions 1 to 4), and introduces the gas into the pressure vessel at a predetermined pressure. A gas storage method is provided (claim 5).

  According to the above invention (invention 5), the porous organometallic complex for gas storage as described above can be applied with an aromatic heterocyclic compound or a dicarboxylic acid compound constituting a three-dimensional lattice by applying a predetermined pressure. Gas molecules such as hydrogen molecules can be stably held in the three-dimensional lattice by the intermolecular force of this, so that the pressure-resistant container is filled with this porous organometallic complex powder, By introducing the gas at a predetermined pressure, the gas can be held easily, reliably and stably.

  In the said invention (invention 5), it is preferable to perform the pre-processing which removes the component irreversibly adsorb | sucked to the said porous organometallic complex for gas storage contained in the gas introduce | transduced into the said pressure | voltage resistant container (invention) Item 6).

  According to the above invention (invention 6), when the gas is occluded into the porous organometallic complex for gas occlusion and the gas is released from the complex, the component that inhibits the adsorption of the gas is contained in the complex. Adsorption can be suppressed to a minimum, and deterioration of the porous organometallic complex for gas storage can be prevented.

  In the said invention (invention 5 and 6), it is preferable to perform the pre-processing which removes the water | moisture content contained in the gas introduce | transduced into the said pressure vessel (invention 7).

  According to the above invention (Invention 7), when the gas is occluded in the porous organometallic complex for gas occlusion and the gas is released from the pressed body, the adsorption of water to the complex is minimized. And the deterioration of the porous metal-organic complex for gas storage can be prevented.

  In the above invention (invention 7), it is preferable that the pretreatment for removing the water is contact with a desiccant (invention 8). Furthermore, in the above invention (invention 8), it is preferable that the desiccant is one or more selected from silica gel, molecular sieves, calcium chloride, and diphosphorus pentoxide (invention 9). ).

  In the said invention (invention 5-9), it is preferable that the said gas is what has hydrogen as a main component, and this gas is stored in the said pressure-resistant container on pressurization conditions (invention 10).

  The gas storage method as in the above invention (invention 10) is particularly suitable for occlusion of gas mainly containing hydrogen gas, and application to various uses can be expected by occlusion of hydrogen.

  Thirdly, the present invention relates to a first pressure-resistant container filled with a powder of a porous organometallic complex for gas storage according to the above inventions (inventions 1 to 4), and a desiccant that communicates with the first pressure-resistant container. A gas storage device is provided, comprising: a second pressure-resistant container filled with a gas; and a gas supply unit containing hydrogen as a main component, which communicates with the second pressure-resistant container.

  According to the above invention (invention 11), moisture is first removed from the gas supply means containing hydrogen as a main component by supplying a gas mainly containing hydrogen to the second pressure vessel, and this moisture is further removed. Occludes the gas mainly composed of hydrogen by supplying the gas mainly composed of hydrogen, from which hydrogen has been removed, to the first pressure vessel filled with the powder of the porous organometallic complex for gas occlusion at a predetermined pressure. Therefore, the first pressure vessel can be used as a hydrogen gas source.

  Fourthly, the present invention provides a fuel cell characterized in that electric power is obtained from a gas mainly containing hydrogen supplied from the first pressure vessel in the gas storage device according to the above invention (invention 11). A system is provided (claim 12).

  According to the above invention (invention 12), the fuel cell system can be operated efficiently and simply by supplying the first pressure vessel containing the gas containing hydrogen as a main component to the fuel cell system as a hydrogen gas source. can do.

  According to the porous organometallic complex for gas storage of the present invention, an aromatic heterocyclic compound containing a plurality of layered lattices of metal ions and dicarboxylic acid compounds and containing nitrogen atoms to which the metal ions can coordinate in two or more positions. Since a three-dimensional lattice structure is connected to each other, by applying a predetermined pressure, a molecule of a gas body such as a hydrogen molecule becomes a molecule with an aromatic heterocyclic compound or a dicarboxylic acid compound constituting the three-dimensional lattice. It can be stably held in the lattice by the interstitial force, and is suitable for gas storage. Furthermore, since the intermolecular force described above is weak, the retained gas molecules can be released by reducing the pressure.

It is the schematic which shows the gas storage apparatus which concerns on one Embodiment of this invention. 2 is a graph showing a powder X-ray diffraction pattern of a porous organometallic complex for gas storage in Example 1. FIG. 1 is a schematic diagram showing a molecular structure of a porous organometallic complex for gas storage in Example 1. FIG.

Hereinafter, the porous organometallic complex for gas storage according to the present invention will be described in detail.
The porous organometallic complex for gas storage of the present invention comprises [1] metal ions, [2] dicarboxylic acid compounds (ligands), and [3] nitrogen atoms capable of coordinating two or more of the metal ions. It is a three-dimensional lattice structure comprised by the coordinate bond with the aromatic heterocyclic compound containing.

  Although there is no restriction | limiting in particular as said [1] metal ion, Although ions, such as Mg, Al, Ca, Ti, Mn, Fe, Co, Ni, Cu, Zn, are mentioned, Among these, Cu ion is preferable.

  [2] The dicarboxylic acid compound functions as a ligand, and it is preferable to use an aromatic dicarboxylic acid such as terephthalic acid. As this aromatic dicarboxylic acid, those represented by the following formulas (1) to (6) can be preferably used.

  Furthermore, [3] As the aromatic heterocyclic compound containing a nitrogen atom capable of coordinating two or more of the above metal ions, those represented by the following formulas (7) to (15) can be used.

  Of these, aromatic heterocyclic compounds having 3 or more, more preferably 4 or more heterocycles are particularly preferred.

  [1] a metal ion, [2] a dicarboxylic acid compound (ligand), and [3] an aromatic heterocyclic compound containing a nitrogen atom capable of coordinating two or more of the above metal ions. The porous organometallic complex of the present invention constituted by coordination bonds has a three-dimensional lattice structure in which a plurality of layered lattices of metal ions and dicarboxylic acid compounds are connected to an aromatic heterocyclic compound containing a nitrogen atom. Resulting in a pore structure. Specifically, [1] Cu ion as a metal ion, [2] terephthalic acid (chemical formula (1)) as a dicarboxylic acid compound, and [3] a fragrance containing a nitrogen atom capable of coordinating two or more of the metal ions. When 1,4-di (4-pyridyl) benzene (chemical formula (10)) is used as the group heterocyclic compound, a three-dimensional lattice in which the structure schematically shown in FIG. It has a structure.

And this pore structure can take a predetermined structure according to the molecular structure of the aromatic heterocyclic compound containing the nitrogen atom which is a ligand. For example, when diazabicyclooctane (DABCO) is used as a bidentate ligand containing a nitrogen atom and terephthalic acid (BDC) is used as a dicarboxylic acid ligand, Bull. Chem. Soc. Jpn. 2008, Vol. 81, no. 7, 847. It takes the same crystal structure as the porous organometallic complex [Cu (BDC) (DABCO) _1/2 ] n reported in the above.

The porous organic metal complex for gas storage according to the present invention preferably has a specific surface area of 20 m ² / g or more, more preferably 100 m ² or more, particularly from the viewpoint of hydrogen storage capacity.

  The porous organic metal complex for gas storage of the present invention as described above can store gas molecules in a three-dimensional lattice by applying a predetermined pressure, and has a sufficient gas storage capacity at room temperature. Particularly useful for hydrogen storage. For example, it has a hydrogen storage capacity of 1.0 wt% or more in an atmosphere at a temperature of 298 K and a hydrogen pressure of 35 MPa.

Next, a method for producing the above-described porous organometallic complex for gas storage will be described.
The porous organometallic complex for gas storage according to the present invention comprises [1] a first step of synthesizing a two-dimensional network coordination polymer by reacting a metal ion and [2] an aromatic dicarboxylic acid, and this network. And [3] a second step of bridging an aromatic heterocyclic compound containing a nitrogen atom capable of coordinating bidentate or more.

  Specifically, first, in the first step, a metal salt of a desired metal ion is dissolved in a predetermined solvent, while an aromatic dicarboxylic acid is dissolved in pyridine. And these two liquids are mixed after that.

  The concentration of metal ions in the reaction solution is preferably in the range of 0.05 to 4.0 mol / L, particularly preferably 0.1 to 0.2 mol / L.

  Water is generally used as a solvent for dissolving the metal salt, but a solvent other than water can be used as long as the metal salt can be dissolved.

  The concentration of the aromatic dicarboxylic acid in the reaction solution is preferably in the range of 0.05 to 4.0 mol / L, and particularly preferably 0.1 to 0.2 mol / L. In addition, as the liquid used as the solvent, a solvent other than pyridine can be used as long as the aromatic dicarboxylic acid can be dissolved.

  The amount and molar concentration of the two liquids to be mixed are preferably the same, but the metal ions may be excessive.

  After mixing the two liquids in this way, when left at room temperature for about 1 to 48 hours, blue crystals (two-dimensional network coordination polymer) are precipitated, which are separated by filtration.

  If the reaction time is less than 1 hour, the reaction may not proceed sufficiently. On the other hand, the yield is not improved so much even if the reaction is performed for 48 hours or more.

  The product is filtered by natural filtration using fluted filter paper or the like, and the product remaining on the filter paper is preferably washed 2 to 3 times with the filtrate. After that, the filter paper is spread and the new filter paper is lightly pressed to remove excess solution.

  Subsequently, in the second step, the crystal (two-dimensional network coordination polymer) obtained here is added to a solution in which an aromatic heterocyclic compound capable of coordinating two or more positions is dissolved, and・ Stir.

  At this time, the solvent for dissolving the aromatic heterocyclic compound is not limited as long as the aromatic heterocyclic compound can be dissolved, but in particular, N, N-dimethylformamide or N, N-diethylformamide can be used. It is preferable from the viewpoint of solubility and reaction temperature that either one is used alone or a mixture of both is used.

  Moreover, the reaction temperature of the above reaction is preferably 80 ° C. to 250 ° C., and particularly preferably 100 ° C. to 150 ° C. When the reaction temperature is less than 80 ° C., the target porous organometallic complex tends to be hardly formed. On the other hand, when the reaction temperature exceeds 250 ° C., the aromatic heterocyclic compound containing a nitrogen atom capable of bidentate coordination or more used for the reaction may be decomposed.

  In the reaction step, the reaction solution can be heated in an air atmosphere. As a reaction vessel, the reaction can be carried out using an eggplant type flask equipped with a reflux condenser such as a Liebig condenser. Moreover, when reacting at the temperature of 200 degreeC or more, it can also react using closed containers, such as an autoclave.

  The porous organometallic complex thus produced is separated from the reaction solution and washed with a solvent such as methanol, N, N-dimethylformamide, N, N-diethylformamide or the like.

  In most cases, the porous organometallic complex thus obtained physically adsorbs the solvent used in the reaction in the pores, but these are removed by vacuum decompression and dried. Thus, the target porous organometallic complex can be taken out.

  Although the said drying process may be performed at room temperature, normally it is preferable to carry out at 80 to 250 degreeC, and it is especially preferable to carry out at 100 to 150 degreeC. If the temperature is 80 ° C. or lower, drying may be insufficient, and if it exceeds 250 ° C., the porous organometallic complex may be decomposed. In this way, the intended porous organometallic complex for gas storage can be obtained.

  Next, a gas storage method and gas storage apparatus using a porous organometallic complex for gas storage according to the present embodiment will be described with reference to the accompanying drawings.

  FIG. 1 is a schematic view showing a gas storage device capable of performing a gas storage method according to an embodiment of the present invention. 1, in this embodiment, the gas storage device 1 includes a first pressure vessel 2 and a second pressure vessel 3, and the first pressure vessel 2 and the second pressure vessel 3 communicate with each other. The pipe 4 communicates. The first pressure vessel 2 is filled with the powder 5 of the gas storage porous organometallic complex, while the second pressure vessel 3 is filled with the desiccant 6.

  And the end of the 1st pressure | voltage resistant container 2 is connected to the gas exhaust pipe 7 provided with valve | bulb 7A. The other end of the second pressure vessel 3 is connected to a gas supply pipe 8 provided with a valve 8A, and a regulator 9A serving as a gas supply means is provided on the base end side of the gas supply pipe 8. The hydrogen gas cylinder 9 is connected. In the figure, reference numerals 10 and 11 denote a valve and a pressure gauge attached to the communication pipe 4, respectively. Therefore, in this embodiment, the gas containing hydrogen as a main component is hydrogen gas.

In the apparatus as described above, as the desiccant 6, silica gel, calcium chloride, diphosphorus pentoxide or the like can be used. Note that H ₂ O, CO, CO ₂ , O ₂ and the like may be removed by filling the second pressure vessel 3 with, for example, molecular sieves instead of the desiccant 6 or in combination.

  Further, the first pressure vessel 2, the second pressure vessel 3, the communication pipe 4, the gas discharge pipe 7 and the gas supply pipe 8 are preferably made of stainless steel such as SUS304 or SUS316.

The effect | action is demonstrated about the said structure.
Hydrogen gas is supplied from the hydrogen gas cylinder 9 with the valve 7A closed and the valves 8A and 10 opened. The hydrogen gas is supplied to the first pressure vessel 2 through the second pressure vessel 3 and the communication pipe 4 filled with the desiccant 6. For this reason, the moisture in the hydrogen gas is sufficiently removed by the desiccant 6.

  It is preferable to set the regulator 9A so that the hydrogen gas supply pressure (pressure of the pressure gauge 11) at this time is 10 to 40 MPa (pressure of the pressure gauge 11). If the hydrogen gas supply pressure is less than 10 MPa, the amount of hydrogen occluded in the powder of the porous metal-organic complex for gas occlusion is not sufficient, but if the pressure exceeds 40 MPa, no further effect of increasing the amount of occluded hydrogen can be obtained. In addition, it is not practical because the pressure resistance of the first pressure vessel 2 needs to be increased.

  When a predetermined amount of hydrogen is stored in the first pressure vessel 2 in this manner, the supply of hydrogen gas from the hydrogen gas cylinder 9 is stopped by closing the valves 8A and 10. In this state, when the first pressure vessel 2 is closed, the communication pipe 4 is removed, and only the first pressure vessel 2 is carried in the vicinity of the fuel cell system, and the gas discharge pipe 7 is provided with a regulator. By connecting to (not shown) and opening the valve 7A to release the pressure, a certain amount of hydrogen can be supplied to obtain electric power.

  Further, the gas storage device of the present embodiment includes a first pressure-resistant container 2 filled with the powder 5 of the porous metal-organic complex for gas storage, and a desiccant 6 filled with the desiccant 6 communicated with the first pressure-resistant container 2. 2 pressure vessel 3 and a hydrogen gas cylinder 9 communicating with the second pressure vessel 3, storing and storing hydrogen gas in the first pressure vessel 3 for a long period of time and using it as a hydrogen gas source Can do.

  Furthermore, hydrogen gas is stored and stored for a long time in the powder 5 of the porous metal-organic complex for gas storage filled in the first pressure vessel 2, and the hydrogen gas supplied from the first pressure vessel 2 is used as fuel. Thus, a fuel cell system that is stable for a long time can be obtained.

Although the present invention has been described above with reference to the accompanying drawings, the present invention is not limited to the above-described embodiment, and various modifications can be made. For example, in the above embodiment, the case of storing hydrogen gas is used, but the present invention can also be applied to other gases such as oxygen, ozone, and CO ₂ .

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example and a comparative example, this invention is not limited to the following Example etc. at all.

[Example 1]
[Synthesis Example of Aromatic Heterocyclic Compound Represented by Formula (10)]
1.36 g of 1,4-dibromobenzene, 4.30 g of 4-pyridineboronic acid, 0.82 g of Pd (dppf) ₂ Cl ₂ and 2.12 g of Na ₂ CO ₃ were mixed with toluene and water (toluene). / Water = 1: 1 (volume ratio)) was added to 50 mL.

  Nitrogen gas was blown into the mixture for 10 minutes for deaeration, and then the mixture was heated at 110 ° C. and refluxed for 72 hours under a nitrogen atmosphere (reference: Organometallics, 2008, 27 (16), pp. 4088-4097).

  Thereafter, heating was stopped, the mixture was allowed to cool to near room temperature, and extracted with toluene. The toluene solution was concentrated with an evaporator, and the obtained solid was recrystallized with ethyl acetate to obtain 1.67 g of 1,4-di (4-pyridyl) benzene as a target product.

[Synthesis example of porous organometallic complex for gas storage]
2.00 g of copper (II) formate tetrahydrate was dissolved in 50 mL of water. 1.47 g of terephthalic acid was put in another container, and 50 mL of pyridine was added and dissolved. These two solutions were mixed, and 4.21 g of blue crystals that precipitated were collected by filtration.

  1.1 g of 1,4-di (4-pyridyl) benzene was weighed and dissolved in 50 mL of N, N-dimethylformamide (DMF). All the blue crystals obtained above were added thereto, and the mixture was refluxed and stirred at 150 ° C. for 48 hours to obtain 2.03 g of a porous organometallic complex for gas storage.

[Characteristic evaluation of porous organometallic complexes for gas storage]
The BET specific surface area measurement at 77K was performed on the thus obtained porous organometallic complex for gas storage. This measurement was performed using a Tristar 3000 manufactured by Micromeritics in a state where a cell containing a porous organometallic complex was immersed in liquid nitrogen. As a result, it was found that the specific surface area was 495 m ² / g.

  Moreover, the powder X-ray diffraction pattern of this porous organometallic complex for gas storage was confirmed. The results are shown in FIG. From this powder X-ray diffraction pattern, it is expected that the porous organometallic complex for gas storage of the example has a three-dimensional porous structure due to the continuation of the structure shown in FIG.

  Moreover, the hydrogen storage amount in 298K was measured with respect to this porous organometallic complex for gas storage. This measurement was performed according to the PCT line measurement method of JIS-H7201. As a result, the hydrogen storage rate at a hydrogen pressure of 10 MPa was 0.5 wt%.

  Furthermore, this pressure-resistant container filled with this porous organometallic complex for gas storage was further attached with a pressure-resistant container filled with a desiccant in the hydrogen introduction part. In this state, hydrogen gas pressure filling and depressurization release were repeated 20 times, and then the hydrogen storage amount of the porous organometallic complex was measured according to the PCT line measurement method of JIS-H7201. As a result, the hydrogen storage rate was 0.5 wt%. Moreover, it was 0.21 wt% when the moisture content contained in the porous organometallic complex after use was measured with the Karl Fischer moisture meter (AQ-2100) of Hiranuma Sangyo Co., Ltd.

[Example 2]
Filling a pressure-resistant container with the porous metal-organic complex for gas storage obtained in Example 1 and attaching a pressure-resistant container filled with a desiccant to the hydrogen introduction part, pressurizing and releasing pressure of hydrogen gas 20 times Was repeated. Thereafter, the hydrogen storage amount of the porous organometallic complex was measured in the same manner as in Example 1. As a result, the hydrogen storage rate was 0.38 wt%. Moreover, when the moisture content contained in the porous organometallic complex after use was measured with the Karl Fischer moisture meter (AQ-2100) of Hiranuma Sangyo Co., Ltd., it was 2.5 wt%.

  From Examples 1 and 2 above, it can be seen that drying the hydrogen gas suppresses a decrease in the hydrogen storage rate after repeated use. This is considered to be because water is adsorbed by the porous metal-organic complex for gas storage by repeating the pressurization and depressurization release of hydrogen gas, and the hydrogen gas storage capacity is lowered.

DESCRIPTION OF SYMBOLS 1 ... Gas storage apparatus 2 ... 1st pressure vessel 3 ... 2nd pressure vessel 4 ... Communication pipe 5 ... Powder of porous organometallic complex for gas occlusion (porous organometallic complex for gas occlusion)
6 ... Desiccant 9 ... Hydrogen gas cylinder (gas supply means)

Claims (12)

  A gas comprising a metal ion, a dicarboxylic acid compound, and an aromatic heterocyclic compound containing a nitrogen atom capable of coordinating two or more of the metal ions, and having a pore structure Porous organometallic complex for storage. The porous organometallic complex for gas storage according to claim 1, wherein a measured value of a specific surface area by a BET method is 20 m ² / g or more.   The gas storage according to claim 1 or 2, wherein the metal ion is a metal ion selected from the group consisting of magnesium, aluminum, calcium, titanium, manganese, iron, cobalt, nickel, copper, and zinc. Porous organometallic complex.   The porous organometallic complex for gas storage according to any one of claims 1 to 3, wherein the dicarboxylic acid compound is an aromatic dicarboxylic acid.   A gas storage method comprising filling a pressure-resistant vessel with the powder of the porous metal-organic complex for gas storage according to any one of claims 1 to 4, and introducing the gas into the pressure-resistant vessel at a predetermined pressure. .   The gas storage method according to claim 5, wherein a pretreatment for removing a component irreversibly adsorbed by the porous metal-organic complex for gas storage contained in the gas introduced into the pressure vessel is performed.   The gas storage method according to claim 5 or 6, wherein a pretreatment for removing moisture contained in the gas introduced into the pressure vessel is performed.   The gas storage method according to claim 7, wherein the pretreatment for removing moisture is contact with a desiccant.   The gas storage method according to claim 8, wherein the desiccant is one or more selected from silica gel, molecular sieves, calcium chloride, and diphosphorus pentoxide.   The gas storage method according to claim 5, wherein the gas contains hydrogen as a main component, and the gas is stored in the pressure-resistant container under a pressurized condition.   5. A first pressure-resistant container filled with the powder of the porous metal-organic complex for gas storage according to claim 1, and a second pressure-resistant container filled with a desiccant communicated with the first pressure-resistant container. And a gas supply unit comprising hydrogen as a main component and communicated with the second pressure vessel.   The fuel cell system according to claim 11, wherein electric power is obtained from a gas mainly comprising hydrogen supplied from the first pressure vessel in the gas storage device according to claim 11.

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