JP2010030843A - Catalyst for hydrogen generation and hydrogen generating apparatus using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a catalyst for hydrogen generation for inexpensively and efficiently generating hydrogen, and to provide a hydrogen generating apparatus using the catalyst. <P>SOLUTION: The catalyst for hydrogen generation is prepared by using metal clusters containing a non-platinum element and having ligands surrounding metals, wherein the metal clusters include metal ions having different valances. Thereby, the fuel reforming performance per the cost of metals used can be improved compared to a catalyst using platinum. An inexpensive hydrogen generating apparatus without using expensive platinum can be obtained. The catalyst is applicable to hydrogen firinig internal combustion engines, fuel cell powered automobiles and home-use PEFC (Polymer Electrolyte Fuel Cell). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a hydrogen production catalyst and a hydrogen production apparatus using the catalyst.

As global warming due to carbon dioxide and the like becomes serious, hydrogen is attracting attention as an energy source for the next generation instead of fossil fuels. In addition, cogeneration of power generation facilities has attracted attention in order to promote energy saving by effectively using energy and reducing CO ₂ emissions. Development of a fuel cell that generates power using hydrogen as a fuel is being vigorously developed as a next-generation power generation technology. The fuel cell includes a polymer electrolyte fuel cell (hereinafter abbreviated as PEFC) and a methanol fuel cell (hereinafter abbreviated as DMFC). PEFC is a stationary power generation system for home use, fuel cell vehicles, and DMFC is a new power source that replaces the current Li-ion secondary battery in the field of portable power sources, such as mobile phones, PDAs (Personal Digital Assistance) and notebook PCs. Developed for portable information devices.

  While the development of such a fuel cell body is important, a hydrogen transport, storage and supply system that is indispensable for using hydrogen as a fuel has become a major issue. Since hydrogen is a gas at room temperature, it is difficult to store and transport compared to liquids and solids. In addition, since hydrogen is a flammable substance, there is a risk of explosion when it reaches a predetermined mixing ratio with air.

  As a technique for solving such a problem, hydrocarbon fuel and water vapor are reacted on a catalyst to generate hydrogen, this hydrogen is stored in a hydrogen storage alloy, released at start-up, added to the hydrocarbon fuel, and added to water. A power generation system that performs addition / desulfurization and supplies the fuel cell is shown (for example, see Patent Document 1).

  In recent years, organic hydride systems using hydrocarbons such as cyclohexane and decalin have attracted attention as a hydrogen storage method that is excellent in safety, transportability, and storage capacity. Since these hydrocarbons are liquid at room temperature, they are excellent in transportability.

  For example, toluene and 1-methylcyclohexane are cyclic hydrocarbons having the same carbon number, while toluene is an unsaturated hydrocarbon in which the bond between carbons is a double bond, whereas 1-methylcyclohexane is a double hydrocarbon. It is a saturated hydrocarbon without a bond. Toluene is obtained by dehydrogenation of 1-methylcyclohexane, and 1-methylcyclohexane is obtained by hydrogenation of toluene. That is, hydrogen can be supplied and stored by utilizing the dehydrogenation and hydrogenation reaction of these hydrocarbons.

  A method of performing a dehydrogenation reaction by blowing cyclohexane onto a high-temperature catalyst layer with an atomizer and separating a product of hydrogen and benzene into a gas and a liquid with a cooler (see, for example, Patent Documents 2 and 3).

  However, in order to generate hydrogen by utilizing a dehydrogenation reaction typified by the reaction of cyclohexane, the reaction efficiency is low, so it is necessary to increase the reaction efficiency. Furthermore, in practical use, it is necessary to set the dehydrogenation reaction temperature of an organic hydride such as cyclohexane in a high temperature range of 250 to 300 ° C. For this purpose, it is necessary to perform heating with a heater. Since a part of the generated electric power is used, the efficiency is lowered. In addition, in the apparatuses described in Patent Document 2 and Patent Document 3, for example, the apparatus tends to increase in size.

  As a catalyst for dehydrogenation reaction typified by 1-methylcyclohexane, for example, as disclosed in Patent Document 2, platinum, which is the most expensive precious metal, is mainly used as an active component. Therefore, in order to reduce the cost of the hydrogen production apparatus, it is necessary to use a metal other than platinum as an active component. In addition, catalysts prepared by conventional preparation methods have limited performance even when expensive platinum is used as an active ingredient, and even if the same kind of metal is used, high performance that exhibits different characteristics from before. It was necessary to apply a functional catalyst.

JP 7-192746 A JP 2002-274801 A JP 2002-184436 A

  An object of the present invention is to provide a hydrogen production catalyst capable of efficiently producing hydrogen at a low cost and a hydrogen production apparatus using the same.

  That is, the hydrogen production apparatus of the present invention is a hydrogen production apparatus for producing hydrogen from an organic compound, and reacts the organic compound with water vapor to produce hydrogen, or generates hydrogen atoms from the organic compound. A catalyst layer that performs a dehydrogenation reaction to generate hydrogen by desorption is provided, and the catalyst layer includes metal clusters including metals having different valences.

  In addition, the hydrogen production catalyst of the present invention is a hydrogen reforming reaction in which an organic compound reacts with steam to generate hydrogen, or a dehydrogenation reaction in which hydrogen atoms are desorbed from the organic compound to generate hydrogen. A catalyst for production, which is characterized by containing metal clusters containing metals of different valences.

  According to the present invention, hydrogen can be produced efficiently at low cost. For example, hydrogen can be supplied to a distributed power source such as a hydrogen combustion internal combustion engine, a fuel cell vehicle, and a household PEFC.

  Hereinafter, the present invention will be described in detail.

  The hydrogen production catalyst of the present invention uses metal clusters having different valence metal atoms. A metal cluster means a molecule whose periphery is covered with a ligand consisting of three or more metal atoms having a bond between metals. Metal clusters are a group of unique compounds that are positioned between bulk metals (a simple metal) and metal complexes.

Here, the reaction mechanism when a palladium cluster is used as a catalyst for hydrogen production among metal clusters will be described. First, hydrogen in the organic compound in which Pd ⁰ in the palladium cluster is a reactant is adsorbed. Next, oxidized metal ions of Pd ²⁺ or more adjacent to the adsorption site react with the adsorbed hydrogen to generate H ₂ O. By desorbing hydrogen in this way, an adsorption site for hydrogen ions is formed again. Next, preferably, oxygen on the palladium is supplemented by supplying oxygen gas to an oxygen defect site formed by desorption of oxygen. By repeating the above reaction route, the dehydrogenation reaction from the organic compound can be continued.

The reaction mechanism of the steam reforming reaction is that hydrocarbon as a fuel is adsorbed on Pd ⁰ , oxygen ^contained in oxidized metal ions of Pd ²⁺ or more reacts with hydrogen in the hydrocarbon, and then oxygen lattice defects are formed. The oxygen in the water vapor that is generated and supplied for reaction is taken in, and the dissociated hydrogen is combined to generate hydrogen molecules.

  The valence is preferably a mixture of zero and two or more valences. In particular, the number of moles of divalent or higher valent metal ions is preferably larger than the number of moles of zero-valent metal ions. The ratio of the number of moles of zero-valent metal ions is preferably 20 to 50%, the ratio of divalent metal ions is 20 to 50%, and the ratio of tetravalent metal ions is preferably 10 to 50%.

  The particle size of the metal cluster is preferably 160 mm or less. In particular, in the case of palladium clusters, the particle size is preferably in the range of 40 to 160 inches.

  The metal cluster is at least one selected from gold, tungsten, copper, cobalt, nickel, iron, manganese, palladium, rhenium, osnium, iridium, rhodium, ruthenium and platinum. Palladium is preferable.

  Although the catalyst application is different, as a fuel cell electrode catalyst, palladium has high performance following platinum, and it has been confirmed that it is promising as a platinum substitute material as a catalytic active component. Among precious metals, platinum has the highest activity of single metal, but the price is the opposite. Among precious metals, palladium and gold are less expensive than platinum and tend to be more active.

  The content of palladium in the catalyst is preferably 5 to 50% by weight.

  When the valence of Pd metal in the catalyst is quantitatively analyzed by X-ray electron spectroscopy in a high performance Pd cluster catalyst, it is found that the catalyst contains 0, 2, and 4 valences of Pd metal. ing. In addition, when the ratio of tetravalent to zero-valent is increased, the catalyst performance tends to be high. In particular, a catalyst containing only zero-valent has remarkably low performance. Therefore, divalent and tetravalent are required for the reaction.

  Hereinafter, the present invention will be described in detail with reference to examples.

[Example 1]
In this example, a method for producing a hydrogen production catalyst in which Pd clusters are supported on a support and a hydrogen production catalyst in which Pd clusters are not supported on a support will be described.
1. Synthesis Method of Pd Cluster The synthesis of Pd cluster was based on the method of Kaneda et al. (Langmuir, 2002, p. 1849-1855). This preparation method synthesizes two types of Pd ₄ clusters and finally synthesizes Pd ₂₀₆₀ (NO ₃ ) ₃₆₀ (CH ₃ COO) ₃₆₀ O ₈₀ clusters.

0.93 g of palladium acetate and 92.7 cc of acetic acid were placed in a flask, which was placed in an oil bath and heated to 50 ° C. with stirring. 10% -CO / N ₂ gas was bubbled into this solution using a glass pipette as a nozzle. The gas flow rate was 500 cc / min and the ventilation time was 6 hours. When CO was bubbled for a predetermined time, a yellow precipitate was formed at the bottom of the flask. The remaining acetic acid was decanted so that the yellow precipitate was not mixed in, and then a slight amount of remaining acetic acid was evacuated, and evacuated for 30 minutes from the point when the acetic acid ceased to be obtained, thereby obtaining a dried yellow precipitate. The yellow precipitate is a Pd ₄ (CO) ₄ (CH ₃ COO) ₄ .2CH ₃ COOH (abbreviation: PCA) cluster.

PCA (0.556 g), 1,10-phenanthrolene-hydrate (0.249 g), acetic acid (10 cc) were placed in a two-necked flask and stirred at room temperature-air for 30 minutes. As a precipitate, Pd ₄ (C ₁₂ H ₈ N ₂ ) ₂ (CO) ₂ (CH ₃ COO) ₄ clusters were obtained.

After adding 0.015 g of Cu (NO ₃ ) ₂ .3H ₂ O to the flask, the inside of the flask was evacuated, and O ₂ gas was supplied into the flask from a tetra bag equipped with an injection needle. The flask in an oxygen atmosphere was placed in an oil bath and stirred at 90 ° C. for 25 minutes to obtain a Pd ₂₀₆₀ (NO ₃ ) ₃₆₀ (CH ₃ COO) ₃₆₀ O ₈₀ cluster as a black precipitate.

2. Method for supporting Pd clusters on a carrier (supporting Pd ₂₀₆₀ clusters)
The catalyst carrier is an alumina coating formed on an aluminum surface by anodic oxidation using aluminum or a clad material provided with an aluminum layer on a metal surface as a high thermal conductive substrate. In addition, this support is an alumina film formed by anodizing, then expanding the pores formed by anodizing, followed by boehmite treatment and firing. Further, the support is a composite in which pores obtained by anodization are filled with at least one selected from the group consisting of zinc oxide, silica, zirconium oxide, diatomaceous earth (for example, a substance containing SiO ₂ ) and activated carbon. It is a carrier. Pd ₂₀₆₀ (NO ₃ ) ₃₆₀ (CH ₃ COO) ₃₆₀ O ₈₀ clusters were dispersed in acetic acid, and the colloidal solution was impregnated with the carrier prepared by the above method so as to have a predetermined loading amount. The amount of Pd ₂₀₆₀ (NO ₃ ) ₃₆₀ (CH ₃ COO) ₃₆₀ O ₈₀ cluster added was such that the Pd loading was 15.3 wt%. After impregnation, acetic acid was evaporated by evacuating the catalyst plate in a vacuum vessel. Furthermore, Pd ₂₀₆₀ (NO ₃ ) ₃₆₀ (CH ₃ COO) ₃₆₀ O ₈₀ cluster is fixed by treating under vacuum for 2 hours, and Pd ₂₀₆₀ (NO ₃ ) ₃₆₀ (CH ₃ COO) ₃₆₀ O ₈₀ cluster is supported. The catalyst supported on was prepared.

(Pd ₄ cluster support)
By a similar method, Pd ₄ (C ₁₂ H ₈ N ₂ ) ₂ (CO) ₂ (CH ₃ COO) ₄ cluster is supported on the support and Pd ₄ (C ₁₂ H ₈ N ₂ ) ₂ (CO) ₂ (CH A catalyst having ₃ COO) ₄ clusters supported on a carrier was prepared.

_{Pd 4 (C 12 H 8 N} 2) 2 (CO) 2 (CH 3 COO) 4 amount of clusters was set to Pd-supported rate is 15.3wt%.

3. Pd cluster catalyst not using a support Conventionally, in order to improve the catalyst performance in a catalyst, it has been necessary to increase the amount of catalytic active sites, that is, the surface area, by dispersing the active metal on the support. When the performance per unit surface area of the metal cluster of the present invention is high, that is, when the catalyst specific activity is high, it is not necessary to disperse in the support. Therefore, high catalytic activity can be expressed by directly applying the produced metal cluster to a high thermal conductive substrate (for example, an alumina substrate) and using it as a catalyst. In this case, since it is not necessary to use a carrier having low thermal conductivity, the temperature of the catalyst layer can reach the predetermined reaction temperature in a short time, and as a result, the startup time of the hydrogen production apparatus can be shortened. . In addition, it is important for household PEFCs to respond quickly to fluctuations in the electric power load in the home. However, if the heat capacity of the catalyst increases, it becomes impossible to cope with rapid temperature changes. Reduce heat capacity so that the reaction temperature can be changed quickly.

[Example 2]
FIG. 1 shows a system in which the Pd ₂₀₆₀ cluster catalyst (catalyst having Pd ₂₀₆₀ (NO ₃ ) ₃₆₀ (CH ₃ COO) ₃₆₀ O ₈₀ cluster supported on a support) produced in Example 1 is applied to combustion of a hydrogen engine of an automobile. An example is shown. The effect of the present invention is that in combustion in the engine cylinder 6, hydrogen is generated by reforming a part of the fuel on the catalyst, and an appropriate amount is added when the fuel is burned in the engine. Thus, the combustion efficiency can be improved and the unburned content in the exhaust gas can be reduced, so that the fuel consumption of an automobile engine or the like can be reduced. 1-methylcyclohexane 3 as a fuel is supplied from the liquid fuel supply nozzle 2 to the hydrogen production apparatus 1, and 1 as shown by the following equation (1) on the Pd cluster catalyst installed in the hydrogen production apparatus 1. -Dehydrogenation reaction of methylcyclohexane 3 proceeds to produce hydrogen and toluene, each passing through hydrogen introduction pipe 4 and dehydrogenation fuel introduction pipe 5, hydrogen supply nozzle 7, and dehydrogenation fuel supply nozzle 8 Can be efficiently combusted by injecting the gas from the exhaust gas to the upstream position of the intake valve 11.

C ₆ H ₁₁ —CH ₃ → C ₆ H ₅ —CH ₃ + 3H ₂ (1)

[Example 3]
FIG. 2 shows a system in which the Pd ₂₀₆₀ cluster catalyst (catalyst having Pd ₂₀₆₀ (NO ₃ ) ₃₆₀ (CH ₃ COO) ₃₆₀ O ₈₀ cluster supported on a support) produced in Example 1 is applied to combustion of a hydrogen engine of an automobile. An example is shown. Here, an exhaust gas supply nozzle is installed in the hydrogen production apparatus 1, and is installed in the hydrogen production apparatus 1 by introducing an exhaust gas 14 containing oxygen to a certain extent that flows downstream from the exhaust valve 12. In this system, the dehydrogenation reaction of 1-methylcyclohexane proceeds efficiently on the prepared Pd cluster catalyst.

[Example 4]
FIG. 3 shows an embodiment of a system in which a NiO—La ₂ O ₃ catalyst is applied to combustion of an automobile hydrogen engine. In this embodiment, a Pd cluster catalyst is used for the steam reforming reaction. In order to obtain a high fuel conversion rate in the steam reforming reaction, it is usually necessary to set the reaction temperature to about 650 ° C., which is about twice the reaction temperature of the dehydrogenation reaction described in Examples 2 and 3. Temperature is needed. However, in order to increase engine combustion efficiency, a hydrogen concentration of about 30% is sufficient, and therefore the reaction temperature may be a normal temperature of 650 ° C. or lower. The steam reforming catalyst 18 is a nickel-based honeycomb catalyst. The hydrogen production apparatus 1 is installed at an upstream position of the intake valve 11, and a steam reforming catalyst 18 is installed in the hydrogen production apparatus 1 if the catalyst component is NiO—La ₂ O ₃ . The water vapor in the gas introduced through the liquid fuel 3 and the exhaust gas introduction pipe 16 is uniformly mixed in advance in the fuel-steam mixer 19 and supplied from the liquid fuel supply nozzle 2 to the steam reforming catalyst 18. The gas inlet of the exhaust gas introduction pipe 16 is installed at the downstream position of the exhaust valve 12.

[Example 5]
FIG. 4 shows an embodiment of a system in which a NiO—La ₂ O ₃ catalyst is applied to automobile hydrogen engine combustion. The hydrogen production apparatus 1 is installed so as to protrude into the engine cylinder 6. Since the internal temperature of the cylinder is as high as 1000 ° C. or higher, it is a condition that sufficiently proceeds to the equilibrium state of the steam reforming reaction represented by the following equation (2). Since the temperature inside the engine cylinder is about 800 to 1200 ° C., when the liquid fuel is dimethyl ether, the steam reforming reaction as shown by the formula (2) proceeds sufficiently.

CH ₃ —O—CH ₃ + H ₂ O → 4H ₂ + 2CO (2)
The steam reforming catalyst 18 is a NiO—La ₂ O ₃ -based honeycomb catalyst. The hydrogen production apparatus 1 is installed at an upstream position of the intake valve 11, and a steam reforming catalyst 18 is installed in the hydrogen production apparatus 1. The water vapor in the gas introduced through the liquid fuel 3 and the exhaust gas introduction pipe 16 is uniformly mixed in advance in the fuel-steam mixer 19 and supplied from the liquid fuel supply nozzle 2 to the steam reforming catalyst 18.

[Example 6]
FIG. 5 shows an embodiment in which the hydrogen production apparatus of the present invention is mounted on an automobile. The fuel 26 is supplied from the fuel tank 23 to the hydrogen production apparatus 21, and the hydrogen 25 generated by reforming is stored in the buffer tank 24, and then an amount corresponding to the engine load is supplied to the hydrogen engine 22 and burned. . As a result of the reaction of the above-described formula (1), the unreacted liquid fuel 27 is recovered again in the buffer tank 24.

[Example 7]
FIG. 6 is a system diagram showing an embodiment in which the hydrogen production apparatus of the present invention is applied to a household fuel cell system. In FIG. 6, the system is composed of a fuel reformer comprising a hydrogen production device 28, a CO shift reactor 39, and a CO removal device 40, and a PEFC fuel cell 30. In a domestic PEFC system equipped with an autothermal fuel reformer, fuel city gas 31 and air 32 are preheated by an auxiliary combustor 33 and then supplied to a hydrogen production device 28. A part of the water in the hot water tank 35 is heated by the steam generator 42 and supplied to the hydrogen production apparatus 28 as steam. The hydrogen production apparatus 28 is filled with a NiO—La ₂ O ₃ catalyst, and here, the city gas 31 reacts with the steam to generate hydrogen. Water 43 is supplied from the cooling water tank 38 to the PEFC fuel cell 30, and as a result, the heated hot water is stored in the hot water tank 35. The anode exhaust gas 46 discharged from the anode of the PEFC fuel cell 30 is separated into gas and liquid by the steam separator 37 and then introduced into the auxiliary combustor 33, where the unburned portion is combusted.

[Example 8]
FIG. 7 shows an embodiment in which the hydrogen production apparatus of the present invention is applied to social infrastructure. In the metal cluster catalyst 51 filled in the hydrogen production apparatus 50, the hydrogen 63 produced from the fuel 62 by the steam reforming reaction or the dehydrogenation reaction is stored in the hydrogen storage station 52. The hydrogen 63 is transported from the hydrogen storage 52 to a hydrogen station 55 installed in each area by a hydrogen transport vehicle 61. Hydrogen serving as fuel is supplied to the fuel cell vehicle 54 or the hydrogen vehicle 53 at the hydrogen station 55. In addition, fuel cells are installed in the housing complex 57, the hospital 59, and the school 58, and hydrogen is supplied from the mobile hydrogen station 60 thereto. In the general household 56, the household PEFC system described in the seventh embodiment is installed, and here again, hydrogen is generated from the city gas or propane gas by the steam reforming reaction using the hydrogen production catalyst.

An example of the system which applied the Pd cluster catalyst to the hydrogen engine combustion of a motor vehicle. An example of the system which applied the Pd cluster catalyst to the hydrogen engine combustion of a motor vehicle. An example of the system which applied the steam reforming catalyst to the hydrogen engine combustion of a motor vehicle. An example of the system which applied the steam reforming catalyst to the hydrogen engine combustion of a motor vehicle. An embodiment in which a hydrogen production apparatus is mounted on an automobile. The systematic diagram which shows one Example which applied the hydrogen production apparatus to the household fuel cell system. An example of applying hydrogen production equipment to social infrastructure.

Explanation of symbols

1, 2, 28, 50 Hydrogen production device 2 Liquid fuel supply nozzle 3, 26, 62 Fuel 4 Hydrogen introduction pipe 5 Dehydrogenation fuel introduction pipe 6 Engine cylinder 7 Hydrogen supply nozzle 8 Dehydrogenation fuel supply nozzle 9 Spark plug 10 Piston 11 Intake valve 12 Exhaust valve 13 Intake gas 14 Exhaust gas 15 Exhaust gas supply nozzle 16 Exhaust gas introduction pipes 17, 23 Fuel tank 18 Steam reforming catalyst 19 Fuel-steam mixer 20 Liquid fuel introduction pipe 22 Hydrogen engine 24 Buffer tank 25, 63 Hydrogen 27 Liquid fuel 29 Hydrogen-containing gas 30 PEFC fuel cell 31 City gas 32, 41, 44 Air 33 Auxiliary combustor 34, 49 Combustion exhaust gas 35 Hot water storage tank 36 Hot water heater 37 Steam-water separator 38 Cooling water tank 39 CO Shift reactor 40 CO removal device 42 Steam generator 43 Water 45 Hot water 46 Anode exhaust gas 47 Hydrogen-containing gas fuel cell inlet valve 48 Hydrogen-containing gas bypass valve 51 Metal cluster catalyst 52 Hydrogen reservoir 53 Hydrogen car 54 Fuel cell car 55 Hydrogen station 56 General household 57 Apartment house 58 School 59 Hospital 60 Mobile hydrogen station 61 Hydrogen Transport vehicle

Claims (14)

A hydrogen production apparatus for producing hydrogen from an organic compound,
Comprising a catalyst layer for performing a steam reforming reaction for generating hydrogen by reacting the organic compound with water vapor, or a dehydrogenation reaction for generating hydrogen by desorbing hydrogen atoms from the organic compound, the catalyst layer comprising: A hydrogen production apparatus having metal clusters containing metals having different valences.   The hydrogen production apparatus according to claim 1, wherein the catalyst layer further includes a carrier supporting the metal cluster.   The hydrogen production apparatus according to claim 1 or 2, wherein the metal cluster includes a metal having a valence of 0 and a metal having a valence of 2 or more.   The hydrogen production apparatus according to any one of claims 1 to 3, wherein the number of moles of the divalent or higher metal in the metal cluster is larger than the number of moles of the zero-valent metal.   The metal cluster has zero-valent, divalent and tetravalent metals, and the ratio of the number of moles of the zero-valent metal to the total number of moles of these metals is 20 to 50%, The ratio of the number of moles of the divalent metal is 20 to 50%, and the ratio of the number of moles of the tetravalent metal is 10 to 50%, according to any one of claims 1 to 4. Hydrogen production equipment.   The metal cluster contains at least one selected from gold, tungsten, copper, cobalt, nickel, iron, manganese, palladium, rhenium, osmium, iridium, rhodium, ruthenium and platinum. The hydrogen production apparatus according to any one of 5.   The hydrogen production apparatus according to any one of claims 1 to 6, wherein a content of palladium in the catalyst is 5 to 50% by weight.   8. The metal according to claim 1, comprising a metal determined by quantitatively analyzing, by X-ray photoelectron spectroscopy, a mole number ratio of metals having different valences constituting the metal cluster. 9. Hydrogen production equipment.   The hydrogen production apparatus according to claim 8, wherein the metal is palladium.   The hydrogen production apparatus according to claim 1, wherein the hydrogen production apparatus is installed in an automobile.   The hydrogen production apparatus according to claim 10, wherein the hydrogen production apparatus is disposed inside an engine installed in the automobile.   11. The hydrogen production apparatus according to claim 10, wherein the hydrogen production apparatus is directly connected to an engine installed in the automobile and disposed in a pipe through which high-temperature exhaust gas flows.   The hydrogen production apparatus according to any one of claims 1 to 12, further comprising oxygen supply means for supplying oxygen in the steam reforming reaction or the dehydrogenation reaction.   A hydrogen production catalyst that performs a steam reforming reaction that generates hydrogen by reacting an organic compound and steam, or a dehydrogenation reaction that generates hydrogen by desorbing a hydrogen atom from the organic compound, and has a different valence. A hydrogen production catalyst comprising a metal cluster containing a metal.

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