JP2002137901A - Hydrogen generating method and hydrogen generating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydrogen generating method and a hydrogen generating apparatus, which enable to generate enough hydrogen by thermal decomposition of a complex metal hydride at relatively low temperature even under a substatially water-free condition. SOLUTION: In manufacturing hydrogen with thermal decomposition of a complex metal hydride by heating in the presence of a catalyst, the catalyst is composed of at least one kind of material and metal selected from the group consisting of a metal oxide and carbon material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for generating hydrogen, and more particularly, to a method for generating hydrogen by thermally decomposing a complex metal hydride in the presence of a catalyst, and a method for generating hydrogen. The present invention relates to a hydrogen generating apparatus.

[0002]

2. Description of the Related Art In modern society, hydrogen is an important chemical raw material that is used in large quantities in the synthetic chemical industry, petroleum refining, and the like. On the other hand, hydrogen utilization technology as clean energy is considered to play an important role in solving future energy and environmental problems, and the development of a fuel cell that stores hydrogen and uses it as fuel is underway. Have been.

[0003] Such fuel cells are gas operated cells, in which the energy obtained from the reaction of hydrogen and oxygen is directly converted to electrical energy. Because such fuel cells have extremely high efficiency compared to conventional combustion engines, vehicles with fuel cells are not compatible with ZEV (Zero Emissio
n Vehicle).

[0004] On the other hand, as a method of storing hydrogen, a method of compressing and storing in a cylinder, a method of cooling into liquid hydrogen, a method of adsorbing on activated carbon, and a method of using a hydrogen storage alloy have been proposed. Among these methods, it is considered that a hydrogen storage alloy plays a major role in a moving medium such as a fuel cell vehicle. However, hydrogen-absorbing alloys also include weight due to being an alloy (small occlusion amount per unit weight), deterioration due to repeated occlusion and release (pulverization and structural change of alloy), and rare metals. There are many issues to be overcome, such as securing resources.

[0005] In recent years, attention has been focused on alkaline earth metals, alkali metals, and alloys based on them. For example, magnesium has a hydrogen storage capacity of 7.6% by weight as a metal and 3.6% by weight as Mg ₂ Ni. With quantity. However, there has been a problem that it is necessary to raise the temperature to about 300 ° C. or higher in order to release the hydrogen occluded in such a metal or alloy.

Against this background, lithium aluminum hydride (LiAlH ₄ ) and sodium aluminum hydride (NaAl), which are complex metal hydrides, are new sources of hydrogen.
H ₄ ) has attracted attention, and the following reaction formula from lithium aluminum hydride: 3LiAlH ₄ → Li ₃ AlH ₈ + 2Al + 3H ₂ (150-175 ° C.) Li ₃ AlH ₈ + 2Al → 3LiH + 3Al + 1.5 Hydrogen is generated according to H ₂ (180 to 220 ° C.) 3LiH + 3Al → 3AlLi + 1.5H ₂ (387 to 425 ° C.). The maximum amount of hydrogen that can be generated from lithium aluminum hydride is 10.8% by weight.
(Per 1 g of lithium aluminum hydride), which satisfies the energy density required for fuel cell vehicles. In addition, a method is known in which sodium aluminum hydride is thermally decomposed by heating in the presence of an organic titanium compound to generate hydrogen (C. Jensen, R. Zidan,
N. Mariels, A. Hee, C. Hagen, Int. J. Hydrogen Energy,
vol.24, p.461 (1999)).

[0007]

However, in order to generate a sufficient amount of hydrogen by thermally decomposing such a complex metal hydride in a state where water is substantially absent, it is necessary to raise the temperature. Even in the case where sodium aluminum hydride is thermally decomposed in the presence of an organic titanium compound, heating to about 200 ° C. or more is required to generate 4 to 5% by weight of hydrogen.

[0008] The present invention has been made in view of the above-mentioned problems of the prior art, and when generating hydrogen by thermally decomposing a complex metal hydride, even when water is substantially absent. An object of the present invention is to provide a hydrogen generation method capable of achieving a sufficient amount of hydrogen generation at a relatively low temperature and a hydrogen generation apparatus therefor.

[0009]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, in a pyrolysis reaction for heating a complex metal hydride to generate hydrogen, a metal oxide was used as a catalyst. And the use of at least one substance selected from the group consisting of carbonaceous materials and a metal to sufficiently increase the amount of hydrogen generated at a relatively low temperature even in a situation where water is substantially absent. It has been found that the present invention can be performed, and the present invention has been completed.

That is, the hydrogen generating method of the present invention is a method for generating hydrogen by thermally decomposing a complex metal hydride by heating in the presence of a catalyst, wherein the catalyst comprises a metal oxide and a carbonaceous material. The method is characterized by comprising at least one kind of substance selected from a group and a metal.

Further, the hydrogen generating apparatus of the present invention includes a container in which a complex metal hydride and a catalyst are disposed, and a heating means for heating the inside of the container. A hydrogen generator that thermally decomposes a compound by heating in the presence of a catalyst to generate hydrogen, wherein the catalyst comprises a metal and at least one substance selected from the group consisting of metal oxides and carbonaceous materials. An apparatus characterized in that:

In the method and apparatus for generating hydrogen of the present invention, the thermal decomposition reaction of a complex metal hydride is remarkably accelerated by a catalyst comprising a metal and at least one substance selected from the group consisting of a metal oxide and a carbonaceous material. Thus, a sufficient amount of generated hydrogen can be achieved at a relatively low temperature even in a situation where water is substantially absent. The reason why the catalyst according to the present invention remarkably promotes the thermal decomposition reaction of a complex metal hydride is not clear, but a metal having a large oxidizing power and a metal oxide or a carbonaceous material having many acid sites are considered. The present inventors believe that this is achieved by the synergistic effect of

[0013] In the method and apparatus for generating hydrogen of the present invention, the metal is fine noble metal particles having an average particle diameter of 1000 nm or less, and the catalyst is such that the noble metal fine particles are supported on a carrier made of the above substance. Preferably, there is. According to such a combination of the noble metal fine particles and the metal oxide or the carbonaceous material, the thermal decomposition of the complex metal hydride proceeds more efficiently, and the amount of generated hydrogen tends to be further improved.

Furthermore, according to the present invention, it is possible to sufficiently improve the amount of hydrogen generated at a relatively low temperature even in a situation where water is substantially absent. It is preferable to heat the complex metal hydride to a temperature of 100 to 170 ° C. in the presence of the catalyst to thermally decompose it. In the hydrogen generator of the present invention, the heating means controls the inside of the vessel to 100 to 170 ° C. It is preferred to heat to a temperature of ° C.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

The hydrogen generation method of the present invention is a method for generating hydrogen by thermally decomposing a complex metal hydride by heating in the presence of a catalyst, wherein the catalyst is selected from the group consisting of metal oxides and carbonaceous materials. The method is characterized by comprising at least one selected substance and a metal.

That is, the catalyst according to the present invention is a catalyst in which at least one substance selected from the group consisting of a metal oxide and a carbonaceous material coexists with a metal. The coexisting form may be a substance in which the above substance is used as a carrier and a metal is carried on the carrier, or a mixture of both. Among them, those in which a metal is supported on a carrier made of the above substance are preferable because the catalytic activity tends to be higher. Further, it is preferable that the substance is in the form of particles and the metal is in the form of fine particles because the catalytic activity tends to be higher.

Examples of such metal oxides include noble metal elements (Pt, Pd, Rh, Ru, Ir, Os, Au, Ag, etc.) and base metal elements (Y, La, Ce, Pr, Nd, Eu, Gd, Tb, Dy, Ho, Er, Tm, Y
b, Lu, Ca, Mg, Al, K, Ti, Cr, Mn, Fe, Co, Ni, Cu,
Ga, Rb, Sr, Zr, Nb, Mo, In, Sn, Cs, Ba, Ta, W
Etc.) and single or complex oxides of metalloid elements (Si, Ge, As, Sb, etc.), among which titanium oxide (titania), nickel oxide, cerium oxide, zirconia, zeolite, alumina, silicon oxide, oxide Iron, manganese oxide, cobalt oxide, zinc oxide and copper oxide are preferred. The metal oxide according to the present invention may contain a plurality of metal elements such as zeolite and calcium zirconia solid solution, and may further contain a non-metal element.

By using such a metal oxide, the substance itself also acts as a catalyst, and the thermal decomposition of the complex metal hydride is remarkably promoted particularly by a synergistic effect with a metal (preferably a noble metal) described later. In addition, a sufficient amount of hydrogen generation can be achieved at a relatively low temperature even in a situation where water is substantially absent. Although the reason why the metal oxide acts as a catalyst is not clear, the present inventors believe that the metal oxide has a large number of acid sites and that catalytic activity occurs in the thermal decomposition reaction of the complex metal hydride. Is thinking.

The metal oxide according to the present invention is preferably 1000 μm or less, more preferably 100 μm to 10 n.
m, particularly preferably 10 μm to 10 nm. If the average particle size exceeds 1000 μm, the surface area of the particles tends to decrease, and sufficient catalytic activity tends not to be obtained. The specific surface area of the metal oxide is 1 to 1000.
It is preferably about m ² / g, and when the average particle diameter is relatively large, it is preferably porous.

As the carbonaceous material, activated carbon, graphite, activated charcoal, coke, hard carbon (hardly graphitizable carbon) and soft carbon (easy graphitizable carbon) are preferable.
Even when such a carbonaceous material is used, the substance itself acts as a catalyst, and the thermal decomposition of the complex metal hydride is remarkably promoted by a synergistic effect with a metal (preferably a noble metal) described later, and water is formed. Sufficient hydrogen generation can be achieved at relatively low temperatures even in situations where they are substantially absent. The reason why the carbonaceous material acts as a catalyst is not clear, but the present inventors believe that the carbonaceous material also has a large number of acid sites and thus exhibits catalytic activity against the thermal decomposition reaction of the complex metal hydride. Is thinking.

The carbonaceous material according to the present invention is preferably 1000 μm or less, more preferably 100 μm to 10 n.
m, particularly preferably 10 μm to 10 nm. If the average particle size exceeds 1000 μm, the surface area of the particles tends to decrease, and sufficient catalytic activity tends not to be obtained. The specific surface area of the carbonaceous material is 1 to 4000.
It is preferably about m ² / g, and more preferably porous particles.

The shape of the substance according to the present invention is not particularly limited, and a shape such as a powder, a pellet, a monolith, a plate, and a fiber can be selected according to use conditions.

The catalyst according to the present invention is obtained by coexisting a metal with the above substance. Such metals include noble metals (Pt, Pd, Rh, Ru, Ir, Os, Au, Ag, etc.) and base metals (Y, La, Ce, Pr, Nd, Eu, Gd, Tb, Dy , Ho, Er,
Tm, Yb, Lu, Ca, Mg, Al, K, Ti, Cr, Mn, Fe, Co, N
i, Cu, Ga, Rb, Sr, Zr, Nb, Mo, In, Sn, Cs, Ba, Ta,
W, etc., among which noble metals (Pt, Pd, Rh, Ru, I
r, Os, Au, Ag) are preferred, and platinum group elements (Pt, Pd, Rh,
Ru, Ir, Os) are particularly preferred. By using such a metal in coexistence with the substance, the thermal decomposition of the complex metal hydride is remarkably promoted by the synergistic effect of the catalytic action of the metal and the catalytic action of the substance, and water substantially exists. Even under no circumstances, a sufficient amount of hydrogen can be achieved at a relatively low temperature. Although the reason why the metal acts as a catalyst is not clear, it is assumed that the metal (preferably a noble metal) has a large oxidizing power, so that catalytic activity occurs in a reaction system in which a complex metal hydride is thermally decomposed to generate hydrogen. The present inventors consider.

The metal according to the present invention is desirably a fine particle having an average particle size smaller than that of the particles made of the above substances, preferably 1000 nm or less, more preferably 100 nm or less, particularly preferably 10 nm or less. is there. If the average particle size exceeds 1000 nm, the surface area of the particles tends to decrease, and sufficient catalytic activity tends to be not obtained.
Further, the metal may partially contain a metal compound such as an oxide of the metal, but is preferably a simple metal because the oxidizing power is further enhanced.

The metal content in the catalyst according to the present invention is:
It is preferably from 0.01 to 50% by weight, more preferably from 0.5 to 10% by weight, based on the total weight of the catalyst. When the content of the metal is less than 0.01% by weight, a catalytic action by the metal cannot be obtained, and a sufficient yield of hydrogen tends not to be achieved.

The method for causing a metal to coexist with the above substance is not particularly limited. For example, a method using a metal and / or a metal precursor (metal halide, nitrate, carbonate, acetylacetonate, tetraammine salt, alkoxide, etc.) is used. The catalyst according to the present invention can be obtained by loading a metal on a carrier made of the above substances by a technique such as a so-called impregnation method, precipitation method, kneading method, ion exchange method, etc., but International Publication No. WO 99/10167. It is preferable to obtain the catalyst according to the present invention by a supercritical method using a supercritical fluid described in (1). By using supercritical fluid, 10
Since the particles have a fine particle size of 1 nm or less (particularly preferably 1 nm or less) and are dispersed and supported as a single metal on the carrier, the catalytic activity is further improved, and the amount of hydrogen generation tends to be more remarkably improved.

Further, after the metal and / or the metal precursor are supported on the carrier as described above, if necessary, a calcination treatment in nitrogen or air, and / or hydrogen, carbon monoxide or hydrocarbon is performed. It is preferable to perform a reduction treatment in an atmosphere containing (methane, acetaldehyde, etc.). Although the conditions of such a baking treatment and a reduction treatment are not particularly limited, for example, a condition of heating at a temperature of 350 to 800 ° C. for 1 to 10 hours is employed.

The above-mentioned supercritical method is a method in which a solution containing a metal and / or a metal precursor and a solvent is brought into contact with a carrier in a state where the solvent becomes a supercritical fluid, so that the metal and / or This is a method for supporting a metal precursor, and thereafter, if necessary, a baking treatment and / or a reduction treatment are carried out to obtain the catalyst according to the present invention. here,
Supercritical fluid means a fluid heated above the critical temperature. Therefore, the state in which the solvent becomes a supercritical fluid means a state in which the solvent is heated to a temperature higher than the critical temperature of the solvent.
The pressure is not particularly limited, but is preferably equal to or higher than the critical pressure. Such a supercritical fluid has the same dissolving capacity as a liquid, and has diffusivity and viscosity close to that of a gas, so that metal can easily and quickly penetrate deep into the pores of a carrier or into very fine pores. Can be done. In addition, the above-mentioned dissolving ability depends on temperature, pressure, entrainer (additive)
Etc. can be adjusted.

The solvent used as the supercritical fluid is not particularly limited, but includes, for example, hydrocarbons such as methane, ethane, propane, butane, ethylene and propylene; monools such as methanol, ethanol and isopropanol; ethylene glycol Glycol such as propylene glycol; ketones such as acetone and acetylacetone; ethers such as dimethyl ether; carbon dioxide; water; ammonia; chlorine; chloroform; Further, in order to increase the solubility of the metal and / or the metal precursor in the supercritical fluid, alcohols such as methanol, ethanol, and propanol; ketones such as acetone, ethyl methyl ketone and acetylacetone;
Aromatic hydrocarbons such as toluene and xylene can be used as the entrainer.

In the hydrogen generating method of the present invention, the complex metal hydride is brought into contact with a catalyst comprising a metal and at least one substance selected from the group consisting of a metal oxide and a carbonaceous material as described above. Heat in the state. Thereby, the thermal decomposition reaction of the complex metal hydride is remarkably accelerated, and even in a condition where water is substantially absent, hydrogen is produced at a relatively low temperature in a high yield, and a sufficient amount of hydrogen is generated. . As described above, according to the present invention, even at a relatively low temperature, the complex metal hydride is thermally decomposed in the presence of the catalyst to achieve a sufficient amount of generated hydrogen. ~ 170 ° C is preferred. If the reaction temperature is lower than 100 ° C., the catalytic activity tends to decrease and a sufficient amount of generated hydrogen tends to be not achieved. On the other hand, even if the temperature exceeds 170 ° C., the amount of generated hydrogen is hardly increased, so that much heating is required. Efficiency tends to be poor due to the need for energy.

Such a complex metal hydride has a high content of hydrogen and is efficiently produced by the catalyst, so that LiAlH ₄ , NaAlH ₄ , LiBH ₄ , NaBH ₄ , KAlH ₄ , KAl
BH ₄ , Mg (BH ₄ ) ₂ , Ca (BH ₄ ) ₂ , Ba (BH ₄ ) ₂ , Sr (BH ₄ ) ₂ , Fe (BH
₄ ) ₂ is preferable, among which LiAlH ₄ and NaAlH ₄ are more preferable because they are easily thermally decomposed and have a high theoretical capacity of hydrogen generation,
LiAlH ₄ having such a theoretical capacity of at most 10.8% by weight is particularly preferred. The complex metal hydride may be used alone or in combination of two or more.

The reaction system in the hydrogen generation method of the present invention may contain components other than the complex metal hydride and the catalyst. Other components include gases inert to the reaction (nitrogen, CO ₂ , Ar, etc.). On the other hand, if oxygen is present, the generated hydrogen tends to burn easily, so it is better to exclude it as much as possible.

In the method for generating hydrogen of the present invention,
Even in a situation where water is substantially absent, since the complex metal hydride is thermally decomposed by the above-mentioned catalyst at a relatively low temperature and a sufficient amount of hydrogen is achieved, water is substantially contained in the reaction system. Preferably, it is not present. Here, “the situation in which water is substantially absent” means that the presence of water that is inevitably present in the reaction system is allowed, but water or steam is externally added to the reaction system. No situation.

Next, a preferred embodiment of the hydrogen generator of the present invention will be described. FIG. 1 is a schematic view showing an example of a preferred embodiment of the hydrogen generator of the present invention. The hydrogen generator 1 is used to heat a reaction vessel 3 having a hydrogen discharge pipe 2 and the inside of the reaction vessel 3. The reaction vessel 3 is filled with the complex metal hydride 5 and the catalyst 6 according to the present invention.

According to such a hydrogen generator 1, when the inside of the reaction vessel 3 is heated to a predetermined temperature (preferably 100 to 170 ° C.) by the heater 4, the complex metal hydride 5
Is thermally decomposed in the presence of the catalyst 6 to produce hydrogen in a high yield. The hydrogen 7 obtained by the hydrogen generator 1 is discharged from the hydrogen discharge pipe 2 and supplied to, for example, a reaction cell (not shown) for a fuel cell. Therefore, by controlling the internal temperature and the like of the reaction vessel 3 according to the amount of energy to be taken out as electric power, the amount of hydrogen supplied to the reaction cell for the fuel cell can be adjusted, and the required electric output can be obtained. it can.

Further, in the hydrogen generator 1 of the present invention, the complex metal hydride 5 is thermally decomposed by the catalyst 6 at a relatively low temperature even in a situation where water is not substantially present in the reaction system. Hydrogen 7 is sufficiently generated. Therefore, according to the hydrogen generator 1 of the present invention, the energy required for hydrogen generation is reduced and efficiency is improved, and a device for supplying water into the reaction system and a device for collecting water from the reaction system are not required. Becomes Therefore, the hydrogen generator 1 of the present invention is particularly effective as a hydrogen generator for a fuel cell vehicle which requires high efficiency and compactness.

The preferred embodiment of the hydrogen generator of the present invention has been described above, but the apparatus of the present invention is not limited to the above embodiment. For example, the heating device 4 to be used is not particularly limited, and may be an electric heater, an electromagnetic heater, or a heating unit of a type using external heat. Further, a complex metal hydride 5
May be further provided for supplying (replenishing) the complex metal hydride.

[0039]

EXAMPLES Hereinafter, the present invention will be described more specifically based on examples and comparative examples, but the present invention is not limited to the following examples. Example 1 100 g of zirconia powder (manufactured by Daiichi Kagaku) was immersed in 100 ml of a rhodium-containing nitric acid solution (rhodium content: 15 g / l, manufactured by Tanaka Kikinzoku Co., Ltd.) to support a rhodium precursor on the zirconia powder. The powder is then mixed with 250
C. for 5 hours, and calcined in air at 450.degree. C. for 2 hours, and further reduced in hydrogen at 300.degree. C. for 3 hours to reduce rhodium on a zirconia powder (rhodium content). : 1.5% by weight).

Using the catalyst thus obtained, the amount of hydrogen generated was determined as follows. That is,
50 mg of the above catalyst and 50 m of lithium aluminum hydride
g in a mortar, packed in a 100 ml Erlenmeyer flask, set in an oil bath temperature-controlled to 150 ° C, and a female burette in a Shibata Scientific gas analyzer (product code: 6071-4). The amount of hydrogen generated was determined from the change in the water surface. In addition, 10 minutes and 6
The amount of hydrogen generated during 0 minutes was measured, and the measured value of the amount of hydrogen generated after 10 minutes and 60 minutes, respectively, was used.

The average particle size of the carrier particles and the metal supported was determined by TEM observation, SEM observation or X-ray diffraction. The particle size was determined by X-ray diffraction using an X-ray diffractometer RAD-B manufactured by Rigaku Denki using the following method.

That is, the catalyst was packed in a glass sample cell,
Wide-angle X-ray diffraction intensity curves were measured by a reflection type diffractometer method using CuKα monochromatized by a graphite monochromator as a radiation source. Then, the particle diameter (the thickness of the crystal in the direction perpendicular to the lattice plane) Lc is calculated based on the half-value width β, the wavelength λ, and the Bragg angle θ of the diffraction line by the lattice plane as follows:
Lc = Kλ / βcosθ (where K = 0.90).

The hydrogen generation amount obtained by the above measurement is
The results are shown in Table 1 together with data on the catalyst used. Example 2 500 mg of platinum acetylacetonate in 5 ml of acetone
, And introduced into an autoclave. Further, 1 g of titania powder (manufactured by Sachtleben Chemie GMBH, UV100) was added.
Then, 30 g of dry ice was put therein, the autoclave was sealed, and then heated and pressurized to a temperature of 150 ° C. and a pressure of 300 kg / cm ² for 2 hours, and platinum acetylacetonate was supported on titania powder in a state where carbon dioxide was used as a supercritical fluid. I was sorry. Next, the titania powder was dried at 105 ° C. for 1 hour to obtain a catalyst (platinum amount: 1.3% by weight) in which platinum was supported on titania.

The catalyst 10 thus obtained is
The amount of generated hydrogen was determined in the same manner as in Example 1 except that 0 mg was used, and the obtained data is shown in Table 1 together with data on the catalyst using the obtained data. Example 3 The amount of hydrogen generated was determined in the same manner as in Example 1 except that 50 mg of platinum carbon (amount of platinum: 50.0% by weight, specific surface area: 7 m ² / g) manufactured by Kishida Chemical Co., Ltd. was used, and the obtained data was obtained. Are shown in Table 1 together with data on catalysts using Examples 4 to 6 In the same manner as in Example 1 except that platinum-activated carbon (amount of platinum: 5.0% by weight, specific surface area: 719 m ² / g) manufactured by Wako Pure Chemical Industries in the amount shown in Table 1 was used as a catalyst. The amount of hydrogen generated was determined, and the obtained data is shown in Table 1 together with data on the catalyst using the obtained data. Example 7 Example 4 except that 50 mg of sodium aluminum hydride was used instead of 50 mg of lithium aluminum hydride.
The amount of generated hydrogen was determined in the same manner as in Example 1 and the obtained data is shown in Table 1 together with data on the catalyst using the obtained data.

[0045]

[Table 1]

Comparative Example 1 The amount of hydrogen generated was determined in the same manner as in Example 1 except that the catalyst was not added, and the obtained data are shown in Table 2. Comparative Example 2 As a catalyst, tetrabutoxytitanium (Ti
Using (OBu) ₄ ), a uniform paste was prepared by mixing 50 mg of tetrabutoxytitanium and 50 mg of lithium aluminum hydride to form a uniform paste. And the obtained data are shown in Table 2. Comparative Example 3 The amount of generated hydrogen was determined in the same manner as in Example 7 except that the catalyst was not added, and the obtained data is shown in Table 2. Comparative Example 4 As a catalyst, tetrabutoxytitanium (Ti
Using (OBu) ₄ ), a uniform paste obtained by mixing 50 mg of tetrabutoxytitanium and 50 mg of sodium aluminum hydride was filled in a 100-ml Erlenmeyer flask, and the amount of hydrogen generated was the same as in Example 1. ,
Table 2 shows the obtained data.

[0047]

[Table 2]

As is clear from the results shown in Tables 1 and 2, according to the catalyst of the present invention in which metal oxide or carbonaceous material particles carry metal fine particles, when no catalyst is used, Naturally, it is confirmed that the thermal decomposition of the complex metal hydride at a relatively low temperature of 150 ° C. is remarkably promoted and the amount of generated hydrogen is remarkably improved as compared with the case where the conventional catalyst (tetrabutoxytitanium) is used. Was done.

[0049]

As described above, according to the hydrogen generating method and the hydrogen generating apparatus of the present invention, when hydrogen is generated by thermally decomposing a complex metal hydride, the hydrogen generation is carried out under the condition that water is substantially absent. Even at a relatively low temperature, the thermal decomposition reaction of the complex metal hydride is remarkably accelerated, and a sufficient amount of hydrogen is generated. Therefore, the hydrogen generation method and the hydrogen generation device of the present invention are very useful in making complex metal hydrides usable as a hydrogen supply source for fuel cells.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a preferred embodiment of a hydrogen generator according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Hydrogen generator, 2 ... Hydrogen discharge pipe, 3 ... Reaction vessel, 4
... heating device, 5 ... complex metal hydride, 6 ... catalyst, 7 ... hydrogen.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuhiro Fukumoto 41-cho, Yokomichi, Nagakute-cho, Aichi-gun, Aichi Prefecture Inside Toyota Central Research Laboratory Co., Ltd. (72) Inventor Osamu Sasaki Nagakute-machi, Oguro-machi, Aichi-gun 41, Yokomichi, Toyota Central Research Laboratory Co., Ltd. (72) Inventor Toshio Yamamoto, 41, Chuchu Yokomichi, Nagakute-cho, Aichi-gun, Aichi, Japan Toyota Motor Central Research Laboratory Co., Ltd. (72) Inventor Yasuaki Kawai Aichi No. 41, Toyota Chuo Research Institute, Nagakute-machi, Aichi-gun, Toyoda Central Research Institute Co., Ltd. (72) Inventor Hiroaki Hayashi 41, Toyota-Chuo Research Institute, Inc. Reference) 4G069 AA03 AA08 BA04B BA05B BA08A BA08B BB02A BB02B BB04A BC71B BC75B CC40 DA05 EA01Y EB18X EB18Y FA02 FB14 FB80

Claims (6)

[Claims] 1. A method for generating hydrogen by thermally decomposing a complex metal hydride by heating in the presence of a catalyst, wherein the catalyst is at least one selected from the group consisting of metal oxides and carbonaceous materials. A method for generating hydrogen, characterized by comprising a substance and a metal. 2. The method according to claim 1, wherein the complex metal hydride is thermally decomposed by heating to a temperature of 100 to 170 ° C. in the presence of the catalyst. 3. The method according to claim 1, wherein the metal is fine noble metal particles having an average particle diameter of 1000 nm or less, and the catalyst is such that the noble metal fine particles are supported on a carrier made of the substance. The hydrogen generation method according to 1. 4. A container having a complex metal hydride and a catalyst disposed therein, and heating means for heating the inside of the container, wherein the complex metal hydride is heated in the presence of the catalyst. A hydrogen generator that generates hydrogen by being thermally decomposed by: wherein the catalyst is made of a metal and at least one substance selected from the group consisting of a metal oxide and a carbonaceous material. Hydrogen generator. 5. The heating means is configured to maintain the inside of the container at 100
The hydrogen generator according to claim 4, wherein the hydrogen generator is heated to a temperature of from about 170C to about 170C. 6. The method according to claim 4, wherein the metal is fine noble metal particles having an average particle diameter of 1000 nm or less, and the catalyst is such that the noble metal fine particles are supported on a carrier made of the substance. The hydrogen generator according to item 1.