JP2005205265A - Catalyst body, its production method, and hydrogen generation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make a generation speed of hydrogen faster by making a catalytic activity and a reaction surface area of a catalyst body coming into contact with a hydrogen generating agent larger when the hydrogen is generated by making the hydrogen generating agent contact with the catalyst body. <P>SOLUTION: The catalyst body in which a surface of a metal substrate itself is constituted as Raney type catalyst is obtained by alloying the metal substrate becoming a catalyst with an eluting metal, covering with it and then eluting the eluting metal. Alternatively, the catalyst body in which the surface of the metal substrate is integrated and covered with Raney type catalyst metal is obtained. The generation speed of hydrogen is increased, for example, by applying these catalyst bodies to a hydrogen generation device. Further, there is no fear that the catalyst metal is peeled off and generation of hydrogen is stabilized for a long period of time. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a Raney-type catalyst used for, for example, hydrogen generation, a method for producing the same, and a method for generating hydrogen using the catalyst.

  A method of generating hydrogen from an alkaline aqueous solution in which a metal hydrogen complex compound such as tetrahydroborate is dissolved using a catalytic metal is generally known. For example, Patent Document 1 uses metals such as nickel (Ni) and cobalt (Co), hydrogen storage alloys such as magnesium-nickel (Mg-Ni) alloys, or fluorinated products thereof as catalyst metals. There has been proposed a method of generating hydrogen by bringing powder particles into contact with an aqueous alkali solution in which a metal hydrogen complex compound is dissolved.

  In an apparatus for continuously generating hydrogen industrially, it is generally useful to use an alkali aqueous solution of a metal-hydrogen complex compound through a catalyst body in which a catalytic metal is supported on a metal substrate. Thus, the catalyst body in which the catalyst metal is supported on the metal substrate is a support body having a predetermined shape such as a rod shape, a plate shape, a columnar shape, a porous shape, a porous block shape, a net shape or a foam shape. The surface of a metal substrate such as nickel is manufactured by filling a catalyst metal such as platinum with a method such as filling, coating, baking, spraying, plating, or thermal spraying (see, for example, Patent Document 2).

JP 2001-19401 (Claims 2, 4, 5, paragraphs 009, 0010, 0012, 0013) JP 2001-29702 (Claim 1, paragraphs 0009, 0013, 0017, 0018, 0024)

  However, the catalyst body described in Patent Document 2 is obtained by simply coating a metal base material as a support with a catalyst metal. By the way, the hydrogen generation rate is determined by the reaction surface area of the catalytic metal in contact with the metal hydride complex, but the hydrogen generation rate is low because the surface area is small if the catalyst metal is simply supported on the metal substrate. There are challenges.

  In addition, since the generation of hydrogen gas is extremely intense on the surface of the catalyst body, peeling of the catalyst metal from the metal substrate cannot be avoided, the catalytic activity is reduced, and continuous hydrogen generation cannot be performed stably. is there.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a catalyst body having a large surface area and suitable as, for example, a catalyst for generating hydrogen. Another object is to provide a catalyst body that is physically stable. Still another object is to provide a suitable method for producing such a catalyst body. Another object is to provide a hydrogen generation method in which the catalyst body is suitably used.

  The catalyst body of the present invention is characterized in that the surface of a metal substrate that can be a catalyst is configured as a Raney-type catalyst. Another catalyst body of the present invention is characterized in that a Raney-type catalyst metal is integrally coated on the surface of a metal substrate. The metal which is a Raney type catalyst is selected from nickel, iron, chromium, cobalt, copper, chromium, manganese, silver and a nickel-based alloy. The metal substrate in the other invention is selected from, for example, nickel, iron, chromium, aluminum, titanium, zirconium, magnesium, and an alloy of two or more of these metals. Here, the “Raney-type catalyst metal” refers to a metal that has been made Raney by elution operation (development method) to make the catalyst layer porous or have a honeycomb structure.

The method for producing a catalyst body according to the present invention comprises a step of coating a metal base that is effective as a catalyst with an elution metal that can be eluted with an alkali or acid aqueous solution, and then alloying the metal base. And a step of elution of the eluted metal by contacting with an acid aqueous solution.
Another method for producing the catalyst body of the present invention includes a step of integrally coating a metal effective on the surface of the metal substrate, and then an alkali or acid surface on the surface of the metal covering the metal substrate. A step of coating and alloying an eluting metal that can be eluted with an aqueous solution, and then a step of contacting the metal substrate with an aqueous solution of an alkali or acid to elute the eluted metal. .

  Furthermore, another method for producing the catalyst body of the present invention includes a step of coating and integrating an alloy of a metal effective as a catalyst and an eluting metal that can be eluted with an alkali or acid aqueous solution on the surface of the metal substrate, and thereafter And a step of bringing the metal substrate into contact with an aqueous solution of an alkali or acid to elute the eluted metal.

  Further, the catalyst body of the present invention may be applied to, for example, a hydrogen generator, and contacted with an alkali aqueous solution of a metal hydride complex compound to generate hydrogen gas. In this case, the metal hydrogen complex is preferably tetrahydroborate.

  According to the catalyst body of the present invention, since the Raney-type catalyst is formed on the surface portion of the metal substrate, high catalytic activity and a large surface area can be ensured, so that it is reacted with, for example, a hydrogen generator with high efficiency. be able to. In addition, since the degree of freedom of the form of the catalyst body is large, it is possible to appropriately create the form according to the application location, for example, the shape and size of the catalyst body, and therefore the degree of freedom in designing the reactor is increased and the handling is convenient. It also has the effect of becoming. And about the catalyst body which used the surface of the metal base material itself as Raney type metal, peeling of a catalyst metal cannot occur substantially and a catalytic reaction is stabilized for a long time. For this reason, when this catalyst body is applied to a hydrogen generator, the hydrogen generation speed increases, it is easy to control, and continuous hydrogen generation can be performed stably.

(First embodiment)
1st Embodiment of the manufacturing method of the catalyst body which concerns on this invention is described. First, a surface of a metal substrate made of a metal effective as a catalyst (hereinafter referred to as catalyst metal), for example, is coated with a metal that can be eluted into an alkali or acid aqueous solution (hereinafter referred to as an eluted metal) to form an alloy. In this alloying step, the eluted metal powder is coated on the surface of the metal base material together with, for example, a pressure sensitive adhesive such as methyl cellulose, and heated to, for example, the melting point of the eluted metal in a heating furnace. The metal base material and the eluted metal are fused and alloyed. This alloying process may employ a method in which the eluted metal is sprayed onto the metal substrate, or the eluted metal is sputtered and the sputtered particles are deposited on the surface of the metal substrate made of the catalyst metal. Alternatively, the eluted metal may be deposited by vapor deposition such as CVD (Chemical Vapor Deposition).

  Examples of the catalyst metal include metals such as nickel (Ni), iron (Fe), cobalt (Co), copper (Cu), chromium (Cr), manganese (Mn), and silver (Ag), or nickel-iron, nickel. -Nickel alloys, such as copper, nickel-cobalt, and iron-cobalt, can be used. The shape of the metal substrate is not limited to a plate shape, and may be a rod-like, block-like, cylindrical, columnar, conical, prismatic, pyramidal or rod-like metal substrate, or porous. You may use what shape | molded the body in these shapes. Examples of the eluting metal include aluminum (Al), silicon (Si), magnesium (Mg), and zinc (Zn), and aluminum is generally used.

  The composition of the alloy of the metal substrate made of such a catalyst metal and the eluted metal varies depending on the type of each metal, but generally the composition ratio is preferably 50% by weight or less for the catalyst metal and 50% by weight or more for the eluted metal. In particular, the catalyst metal is preferably adjusted to 20 to 50% by weight. In the step of alloying the eluted metal with the metal base material made of the catalyst metal described above, for example, aluminum as the eluted metal is alloyed with nickel as the catalyst metal.

  Subsequently, the alloyed metal base material is contacted, for example, immersed in an eluent composed of an alkali or acid aqueous solution to elute the eluted metal. As the eluent, an aqueous solution of an alkali or an acid is used depending on the content of the eluted metal, but generally 5 to 40% by weight of an aqueous solution of sodium hydroxide (NaOH) is used in excess of the theoretical amount. When such an elution operation (development method) is performed, only the eluted metal is removed from the surface of the metal substrate made of the catalyst metal, and a large number of pores are formed. In this way, a catalyst body configured as a catalyst metal (Raney-type catalyst metal) in which a large number of pores are formed on the surface of a metal substrate that can be a catalyst can be obtained.

  Further, the temperature of the alkaline aqueous solution and the immersion time of the metal substrate for the development treatment are determined by the composition of the alloy and the concentration of the alkaline aqueous solution, but the temperature of the alkaline aqueous solution is generally room temperature to 120 ° C., and the immersion time is 1 to 3 hours is preferred. After the elution operation is completed, it is desirable to wash the alloy formed on the surface of the metal substrate up to litmus neutrality and store it so as not to be exposed to air.

  Thus, a large surface area can be ensured by making the surface of the metal substrate made of the catalyst metal Raney and making the catalyst layer porous or having a honeycomb structure. Therefore, by using such a catalyst body, for example, the reaction surface area in contact with the hydrogen generator is increased, so that it can be reacted with the metal hydrogen complex compound with high efficiency, and hydrogen can be generated faster.

  In addition, when this catalyst body is applied to, for example, a hydrogen generator, which will be described later, since this catalyst body has a Raney surface on the surface of the metal base material, which is a catalyst metal, the catalyst metal cannot be peeled off. Therefore, continuous hydrogen generation can be stably performed without lowering. Furthermore, the degree of freedom of the form of the catalyst body is greater than that of the catalyst in which the entire granular material is Raney, or the form according to the application location, for example, the shape and size of the catalyst body can be appropriately created. There is an effect that the degree of freedom increases and the handling becomes convenient.

As another example of the manufacturing method of this embodiment, the metal base material made of the above-mentioned catalyst metal is immersed in a crucible containing molten elution metal in a short time, and the elution metal is immersed on the surface of the metal base material. After the melt is brought into contact and fused, only the surface of the metal substrate is alloyed, and then the eluted metal is eluted in the same manner, whereby a catalyst body similar to the above can be obtained. In this method of manufacturing a catalyst body, for example, when a nickel base material is immersed in a crucible in which aluminum as an elution metal is melted, the temperature rises due to heat generation, and the metal base material and the elution metal are easily alloyed. There is an advantage that it can be adjusted.
(Second Embodiment)
A second embodiment of the method for producing a catalyst body according to the present invention will be described. First,
For example, the catalyst metal described in the first embodiment is coated on the surface of a plate-shaped metal substrate, and heated to a predetermined temperature in a heating furnace to fuse and integrate the metal substrate and the catalyst metal. . The metal substrate used here may be any material that can be fused and integrated with the catalyst metal described above. In addition to the catalyst metal itself, for example, iron (Fe), nickel (Ni), chromium (Cr), Aluminum (Al), titanium (Ti), zirconium (Zr), magnesium (Mg), or an alloy thereof is used.

  Subsequently, this metal substrate is coated with the eluted metal described in the first embodiment, heated to a predetermined temperature in a heating furnace, and the eluted metal is fused to the surface of the catalytic metal covering the metal substrate. And alloyed. As an example of such a structure, the surface of an iron plate as a metal substrate is coated with nickel as a catalyst metal, and an alloy obtained by alloying this nickel with aluminum as an elution metal can be raised. Then, the metal substrate is contacted, for example, immersed in an aqueous solution of an alkali or acid to elute the eluted metal. According to such a manufacturing method, it is possible to obtain a catalyst body formed by integrally coating the surface of the metal substrate with Raney-type catalyst metal, and the surface of the metal substrate is made Raney, so that a large surface area is secured. be able to. And since the joint interface between the metal substrate and the catalyst metal is fused and integrated by heating, the catalyst metal is firmly supported on the surface of the metal substrate. There is no fear of this, and there is an effect equivalent to that of the catalyst body obtained in the first embodiment.

  Further, as another example of the method for producing a catalyst body according to this embodiment, a metal base coated with a catalyst metal is immersed in a crucible containing molten elution metal, and the surface of the catalyst metal is immersed in the crucible. The melted metal of the eluted metal may be brought into contact with each other, fused and alloyed, and then the eluted metal may be eluted in the same manner.

As a method for integrating the metal substrate and the catalyst metal, sputtering and CVD methods may be used, and as a method for alloying the eluted metal with the catalyst metal, a spraying method or the like may be used as described above.
(Third embodiment)
A third embodiment of the method for producing a catalyst body according to the present invention will be described. First, the catalyst metal and the eluted metal powder described in the first embodiment are mixed in a predetermined amount in, for example, a container, and this mixture is described in the plate-like second embodiment, for example. A metal base material is coated and heated at a predetermined temperature in a heating furnace. By heating, the catalyst metal and the eluted metal are alloyed on the surface of the metal substrate, and the metal substrate and the catalyst metal are integrated. Then, the metal substrate is contacted, for example, immersed in an aqueous solution of an alkali or acid to elute the eluted metal. According to such a manufacturing method, a catalyst body similar to that of the second embodiment can be obtained, and an effect equivalent to that of the catalyst body obtained in the first embodiment can be obtained.

As another method for producing the catalyst body according to the present invention, the metal base material is immersed in a crucible containing the molten catalyst metal and the eluted metal, and the catalyst metal and the eluted metal are melted on the surface of the metal base material. After the objects are brought into contact with each other and fused, and the metal substrate and the catalyst metal are alloyed, the eluted metal may be eluted in the same manner.
(Application example of catalyst body)
Next, an example of a hydrogen generator using the catalyst body described in the first embodiment in the catalyst body described in the first, second, and third embodiments of the present invention will be described with reference to FIG. Briefly described. FIG. 1 is a plan view of an example of a hydrogen generator. In this figure, a hydrogen generating agent is disposed in a hydrogen generating unit 4 from a raw material storage unit 1 through a regulating valve 2 and a raw material supply pipe 3. For example, it is supplied to the upper end portion 51 of the plate-like catalyst body 5 of the present invention. As the hydrogen generator supplied here, an alkaline aqueous solution in which a metal hydrogen complex compound such as tetrahydroborate is dissolved is used. For example, a solution obtained by dissolving sodium borohydride (NaBH4), which is a metal hydride complex compound, in an aqueous solution of sodium hydroxide (NaOH), which is an alkaline aqueous solution, is used. This hydrogen generating agent normally does not generate hydrogen gas because the properties of sodium borohydride are stable in an alkali, and when it comes into contact with the catalyst body 5, it causes a chemical reaction as shown in the following formula (1). Hydrogen gas is generated.

NaBH4 + 2H2O → NaBO2 + 4H2 (1)
The supplied hydrogen generator flows along both surfaces of the catalyst body 5 and flows down while forming a thin film, and reaches the lower end portion 52 of the catalyst body 5, during which the metal hydrogen complex compound is expressed by the above formula (1). The hydrogenation reaction shown in FIG. 5 is performed to generate hydrogen gas, which is taken out from the hydrogen gas outlet 6 to the outside. In addition, the metal hydride complex is oxidized during this period to be converted into an oxide, and the aqueous alkali solution containing the oxide is collected in the recovery unit 7. In the figure, 8 is a flange for connecting the raw material storage unit 1 and the hydrogen generation unit 4, 9 is a support rod for the raw material supply pipe 3, and 91 is a hanger.

  FIG. 2 is a partial side view showing a contact portion between the raw material supply pipe 3 and the plate-like catalyst body 5, and both sides of the front end portion of the raw material supply pipe 3 supported by the support rod 9 via the hanger 91. The upper part of the catalyst body 5 is inserted between the walls with a slight gap, and the hydrogen generating agent flows down to both surfaces of the catalyst body 5 through the gap.

  Since the surface of the metal substrate is made Raney by the elution operation (development method), the catalytic body 5 has a large reaction surface area in contact with the metal hydride complex when applied to the hydrogen generator described above. As shown in this example, the amount of hydrogen gas generated is increased and the catalytic metal cannot be peeled off substantially, so that the catalytic activity does not decrease, and continuous hydrogen generation can be performed stably.

  The same effect can be obtained even if the catalyst bodies described in the second and third embodiments of the present invention are used.

  Further, as another embodiment using the catalyst body of the present invention, for example, a plurality of plate-like catalyst bodies are arranged side by side with a predetermined interval in a reaction vessel containing a predetermined amount of an alkali aqueous solution of a metal hydride complex compound. In the reaction vessel, the metal hydride complex compound may contact the catalyst body to generate H2 gas by a hydrolysis reaction. By providing the catalyst bodies with a predetermined interval in this way, the H2 gas generated between the catalyst bodies can be easily released.

Next, an experiment conducted for confirming the effect of the present invention will be described.
A. Experimental example 1
(Manufacture of catalyst body)
On the surface of a Ni plate (20 × 40 mm, thickness 0.2 mm) as a metal substrate, aluminum powder as an eluting metal was mixed with methyl cellulose as an adhesive and applied and coated. The amount of the aluminum powder applied here was set to eight types of 92 mg, 201 mg, 278 mg, 292 mg, 322 mg, 377 mg, 415 mg, and 499 mg to obtain eight samples. Next, each Ni plate was heated to a temperature of 660 to 680 ° C. in a heating furnace, and the surface Ni and the coated Al were alloyed by heating for 5 minutes. Then, after removing Al that was not alloyed on the surface of the Ni plate taken out from the heating furnace, this Ni plate was immersed in a 20 wt% aqueous sodium hydroxide solution to elute the alloyed Al, and Ni A catalyst body in which the surface of the substrate was made Raney was obtained. The catalyst bodies corresponding to each of the 8 types of aluminum powder (92 mg to 499 mg) applied to the surface of the Ni plate are referred to as Examples 1 to 8.
(Hydrogen generation)
Two catalyst bodies of Examples 1 to 8 were immersed in 50 ml of an aqueous solution prepared by dissolving 5.0 g of sodium borohydride (NaBH4) in 100 ml of a 10% by weight aqueous sodium hydroxide solution. The amount of hydrogen generated at a temperature of 30 ° C. was measured.
(Results and discussion)
FIG. 3 shows the change over time in the hydrogen generation amount for each of the catalyst bodies of Examples 1 to 8, with the vertical axis representing the hydrogen generation amount V [L] and the horizontal axis representing the time T [min]. It is. Examples 1 to 8 correspond to A1 to A8 in FIG. As can be seen from FIG. 3, it can be understood that the generation rate of hydrogen increases as the amount of Al as the eluted metal increases. Further, A10 in FIG. 3 is the theoretical hydrogen generation amount.

FIG. 4 shows the amount of change in hydrogen generation rate with respect to the amount of Al eluted after alloying and the amount of Ni alloyed, and the vertical axis represents the hydrogen generation rate [mL / s] and the horizontal axis represents Al. It is the characteristic view which took quantity and Ni amount [mg]. Examples 1 to 8 correspond to A1 to A8 in FIG. As can be seen from FIG. 4, it can be understood that the hydrogen generation rate is determined by the Al amount (or Ni amount) to be alloyed.
(An endurance test)
In the experiment shown in FIG. 3, 50 ml of an aqueous solution prepared by dissolving 5.0 g of sodium borohydride (NaBH4) in 100 ml of 10 wt% aqueous sodium hydroxide solution using the catalyst body of Example 8 after hydrogen generation was performed. The hydrogen generation was repeated and the same hydrogen generation was repeated, and the durability of the catalyst body was examined.
(Results and discussion)
FIG. 5 shows a change in hydrogen generation rate in repeated hydrogen generation up to 100 times in the catalyst body, wherein the vertical axis represents the hydrogen generation rate [mL / s] and the horizontal axis represents the number of times of use. . The ▲ in FIG. As can be seen from FIG. 5, the hydrogen generation rate slightly decreases with the number of uses, but it can be seen that the catalyst performance and mechanical strength are good even when the same catalyst body is used 100 times.
B. Experimental example 2
(Manufacture of catalyst body)
On the surface of Ni foam (25 × 40 × 1.5 mm), which is a metal substrate, 0.1 g of aluminum powder, which is an eluted metal, was applied and coated. Next, this Ni foam was heated at 660 to 680 ° C. for 5 minutes in a heating furnace, and Al was alloyed with the Ni foam. Thereafter, the Ni foam taken out from the heating furnace is immersed in a 20% by weight sodium hydroxide aqueous solution, and the Al remaining on the surface and the alloyed Al are eluted to form a Ni foam whose surface is made Raney. A catalyst body was obtained. This catalyst body is referred to as Example 9.

In addition, 1 mg of NiAl3 powder (particle size 25 to 90 μm) was applied together with PTFE (polytetrafluoroethylene) to the Ni foam having the same shape as in Example 9, and then immersed in a 20 wt% NaOH aqueous solution. Was eluted to obtain a catalyst body in which the surface of the Ni foam was made Raney. This catalyst body is referred to as Comparative Example 1.
(Hydrogen generation)
The catalyst body obtained in Example 9 and Comparative Example 1 is immersed in an aqueous solution prepared by dissolving 5.0 g of sodium borohydride in 100 ml of 10% by weight aqueous sodium hydroxide solution, and generated at a reaction temperature of 30 ° C. The amount of hydrogen generated was measured.
(Results and discussion)
FIG. 6 shows the change over time in the hydrogen generation amount and temperature of the catalyst body of Example 9, with the vertical axis representing the hydrogen generation amount V [L] and the horizontal axis representing the time T [s]. It is. In FIG. 6, □ indicates the amount of hydrogen generated in Example 9, and ◇ indicates the temperature of the aqueous solution. As can be seen from FIG. 6, the hydrogen generation amount V reaches the theoretical hydrogen generation amount in about 45 minutes.
(An endurance test)
Using the catalyst body of Example 9 after hydrogen generation in FIG. 6, the same hydrogen was immersed in an aqueous solution prepared by dissolving 5.0 g of sodium borohydride in 100 ml of 10 wt% aqueous sodium hydroxide solution. Generation | occurrence | production was repeated and durability of this catalyst body was investigated.
(Results and discussion)
As shown by ◆ in FIG. 5, the hydrogen generation rate of the catalyst body of Example 9 slightly decreases with the number of uses, but the catalyst performance and mechanical strength can be obtained even when the same catalyst body is used 100 times. It turns out that it is favorable.

  On the other hand, in Comparative Example 1, the Raney Ni powder was peeled off in one generation of hydrogen, the aqueous solution became black, the catalyst performance and mechanical strength were greatly reduced, and continuous use was difficult. The reason why the Ni powder peels in this way is simply that NiAl3 is applied to the surface of the Ni foam, and even if Raney NiAl3 is converted to Raney Ni, the Ni foam as a metal substrate and Ni in NiAl3 This is presumed to be because the bond with is weak.

It is a top view which shows an example of the apparatus used in order to implement the catalyst body which concerns on this invention. It is a partial side view which shows the contact part of the raw material supply pipe | tube of FIG. 1, and a plate-shaped catalyst body, for example. In the catalyst body of this invention, it is the characteristic view which showed the relationship between hydrogen generation amount and time. In the catalyst body of the present invention, it is a characteristic diagram showing the amount of change in hydrogen generation rate relative to the amount of Al eluted by alloying and the amount of Ni alloyed. In the catalyst body of the present invention, it is a characteristic diagram showing the relationship between the number of times the catalyst body is used and the hydrogen generation rate. In the catalyst body of this invention, it is the characteristic view which showed the relationship between hydrogen generation amount and temperature.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Raw material storage part 2 Control valve 3 Raw material supply pipe 4 Hydrogen generating part 5 Catalytic body 51 Upper end part 52 of catalytic body 5 Lower end part 6 of catalytic body 5 Hydrogen gas outlet 7 Recovery part 8 Flange 9 Supporting rod 91 Hanging tool

Claims (9)

  A catalyst body characterized in that the surface of a metal substrate that can be a catalyst is configured as a Raney-type catalyst.   A catalyst body comprising a surface of a metal substrate and a Raney-type catalyst metal integrally coated thereon.   The catalyst body according to claim 1 or 2, wherein the metal as the Raney catalyst is selected from nickel, iron, cobalt, copper, chromium, manganese, silver, and a nickel-based alloy.   3. The catalyst body according to claim 2, wherein the metal substrate is selected from nickel, iron, chromium, aluminum, titanium, zirconium, magnesium, and an alloy of two or more of these metals. . Coating the surface of a metal base effective as a catalyst with an eluting metal that can be eluted with an aqueous solution of an alkali or acid, and alloying;
And a step of bringing the metal base material into contact with an aqueous solution of an alkali or an acid to elute the eluted metal. A process of integrating and coating a metal effective as a catalyst on the surface of a metal substrate;
Next, a step of coating the surface of the metal covering the metal substrate with an eluting metal that can be eluted with an aqueous solution of an alkali or an acid to form an alloy;
And a step of bringing the metal base material into contact with an aqueous solution of an alkali or an acid to elute the eluted metal. Coating and integrating an alloy of a metal effective on the surface of the metal substrate and an eluting metal that can be eluted with an alkali or acid aqueous solution; and
And a step of bringing the metal substrate into contact with an aqueous solution of an alkali or an acid to elute a metal that can be eluted. A method for producing a catalyst body, comprising:   A method for generating hydrogen, comprising contacting the catalyst body according to any one of claims 1 to 4 with an alkali aqueous solution of a metal hydride complex compound to generate hydrogen gas. 9. The method for generating hydrogen according to claim 8, wherein the metal hydrogen complex compound is tetrahydroborate.

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