Hydrogen generation and production methods

Abstract

To secure hydrogen with high purity and at low cost.SOLUTION: The invention is configured to electrically connect: a hydrogen generation promoting member which has an electrical plating film which is formed on a surface of a processed product having a metal surface, by using an acidic electrical plating bath including, pyridine compound and nickel; and metal whose corrosion potential in an alkali solution is less noble relative to that of the nickel, in the state, immerse the hydrogen generation promoting member and the metal in the alkali solution, for generating hydrogen. The hydrogen generation promoting member has high responsiveness to hydrogen generation, therefore, the metal whose corrosion potential is less noble relative to that of the nickel and which contacts the hydrogen generation promoting member instantly starts to dissolve in a reaction solution and generates hydrogen. Drive force of hydrogen generation is generated by a potential difference between metals, therefore no power is required for the hydrogen generation, in addition, it is possible to use classical water substitute and the like for enhancing purity of the generated hydrogen, so that, a complicated device configuration is not required. Therefore, hydrogen with high purity can be secured at low cost.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a hydrogen generation method for generating hydrogen. [Background technology]

[0002] A known method for generating hydrogen is to immerse aluminum in an alkaline solution such as a sodium hydroxide solution. The following patent documents describe a technique for generating hydrogen using such a method: [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-107895 Summary of the Invention [Problem to be solved by the invention]

[0004] Demand for hydrogen is expected to increase in the near future, but a high-purity hydrogen supply source that does not adversely affect fuel cells has yet to be established. There is a need for a high-purity, low-cost hydrogen source and hydrogen generation method that can replace liquid hydrocarbons, steam reforming units, and hydrogen generation methods by water electrolysis, which require desulfurization equipment. Fossil fuel reforming, which produces hydrogen from fossil fuels, can produce hydrogen stably and on a large scale. However, unless carbon dioxide capture and storage (CCS) technology is used, high-purity hydrogen cannot be obtained due to the release of carbon dioxide. Furthermore, not only do steam reforming units and CO converters become necessary, but sulfur compounds present in fuel contaminate fuel cell catalysts, resulting in performance degradation, necessitating the need for desulfurization equipment. Therefore, the complexity of hydrogen production equipment is unavoidable. Furthermore, while hydrogen generation by water electrolysis can produce hydrogen stably and on a large scale, it cannot produce high-purity hydrogen due to the release of carbon dioxide unless CCS technology is used. Furthermore, because this production method uses electricity, the cost of electricity is directly related to production costs. Therefore, an object of the present invention is to secure high-purity, low-cost hydrogen. [Means for solving the problem]

[0005] In order to solve the above problems, the hydrogen generation method of the present invention is characterized in that hydrogen is generated by using an acidic electroplating bath containing a pyridine-based compound and nickel, and immersing a hydrogen generation promoting member having an electroplating film formed on the surface of a workpiece having a metal surface in an alkaline solution while electrically connecting the member to a metal whose corrosion potential in the alkaline solution is more base than nickel, in the alkaline solution.

[0006]

[0007] In order to solve the above problems, the manufacturing method of the present invention is to use a metal having a corrosion potential lower than that of nickel in an alkaline solution. and electrical is immersed in the alkaline solution while connected to This generates hydrogen.The method for producing a hydrogen generation promotion member is characterized in that the hydrogen generation promotion member is produced by forming an electroplating film on the surface of a workpiece having a metal surface using an acidic electroplating bath containing a pyridine-based compound and nickel. [Effects of the Invention]

[0008] In the present invention, the hydrogen generation promoting member exhibits high responsiveness to hydrogen generation. Therefore, metals with corrosion potentials lower than nickel that come into contact with the hydrogen generation promoting member in the reaction solution immediately begin to dissolve and generate hydrogen. In addition, since the driving force for hydrogen generation is the potential difference between the metals, no electric power is required for hydrogen generation. Furthermore, since the classical water displacement method can be used to increase the purity of the generated hydrogen, no complicated device configuration is required. Therefore, by using the present invention, it is possible to obtain high-purity, low-cost hydrogen. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is a table showing the composition of an acidic electroplating bath when forming a hydrogen evolution-promoting film, plating conditions, and the film thickness of the hydrogen evolution-promoting film. [Figure 2] FIG. 2 is a diagram showing the composition of an acidic electroplating bath used in forming an underlying nickel film. [Figure 3] FIG. 10 is a graph showing the amount of hydrogen generated when a promotion member is used, the amount of hydrogen generated in a blank test, and the hydrogen generation ratio for each sodium hydroxide concentration in a sodium hydroxide solution. [Figure 4] FIG. 10 is a graph showing the amount of hydrogen generated when using a promotion member, the amount of hydrogen generated in a blank test, and the hydrogen generation ratio for each liquid temperature of a sodium hydroxide solution. [Figure 5] FIG. 10 is a graph showing the amount of hydrogen generated when a promotion member is used for each area ratio, the amount of hydrogen generated in a blank test, and the hydrogen generation ratio. [Figure 6] This figure shows the amount of hydrogen generated when using a promotion member, the amount of hydrogen generated in a blank test, and the hydrogen generation ratio when a hydrogen generating member and a zinc plate are in contact with each other and immersed in a sodium hydroxide solution. [Figure 7]This figure shows the amount of hydrogen generated when using a promotion member when the hydrogen generating member is in contact with zinc particles and immersed in a sodium hydroxide solution, the amount of hydrogen generated in a blank test, and the hydrogen generation ratio. [Figure 8] FIG. 10 is a graph showing the amount of hydrogen generated when using a promotion member, the amount of hydrogen generated in a blank test, and the hydrogen generation ratio when the hydrogen generating member and an aluminum plate are in contact with each other and immersed in a potassium hydroxide solution. [Figure 9] FIG. 10 is a diagram showing a hydrogen generation promotion member and an aluminum plate immersed in a sodium hydroxide solution while being in electrical contact with each other. DETAILED DESCRIPTION OF THE INVENTION

[0010] The "pyridine compound" described in the present invention is a compound having a pyridine ring, and specifically includes, for example, pyridine, 2-methylpyridine, 3-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 3-ethylpyridine, 4-ethylpyridine, 2-propylpyridine, 3-propylpyridine, 4-propylpyridine, 2,6-dimethylpyridine, 2,4-dimethylpyridine, 3,4-dimethylpyridine, 3,5-dimethylpyridine, 2,4,6-trimethylpyridine, 2,3,5-trimethylpyridine, 2-methylpyridine, 2,4,6-trimethylpyridine, 2,3,5-tri ... -5-Ethylpyridine, 3,5-diethylpyridine, 2-cyanopyridine, 3-cyanopyridine, 4-cyanopyridine, 2-picolinamide, 3-picolinamide, 4-picolinamide, pyridine-2-carboxylic acid, pyridine-3-carboxylic acid, pyridine-4-carboxylic acid, 1-methylpyridinium-2-carboxylic acid hydrochloride, 1-methylpyridinium-3-carboxylic acid hydrochloride, 1-methylpyridinium-4-carboxylic acid hydrochloride, 2-pyridinecarboxaldehyde, 3-pyridinecarboxaldehyde, 4-pyridinecarboxaldehyde Carboxaldehyde, 2-aminopyridine, 3-aminopyridine, 4-aminopyridine, 1-methylpyridinium chloride, 1-ethylpyridinium chloride, 1-propylpyridinium chloride, 1-butylpyridinium chloride, 1-pentylpyridinium chloride, 1-hexylpyridinium chloride, 1-heptylpyridinium chloride, 1-octylpyridinium chloride, 1-nonylpyridinium chloride, 1-decylpyridinium chloride, 1-undecylpyridinium chloride, 1-dodecylpyridinium chloride Examples of suitable pyridinium compounds include 1-benzylpyridinium chloride, 1-benzylpyridinium chloride, 1-benzylpyridinium-3-carboxylate, 1-benzyl-3-carboxylate pyridinium sodium chloride, 2-benzylpyridine, 3-benzylpyridine, 4-benzylpyridine, 2-hydroxypyridine, 3-hydroxypyridine, 4-hydroxypyridine, 2-acetylpyridine, 3-acetylpyridine, 4-acetylpyridine, 2-phenylpyridine, 3-phenylpyridine, 4-phenylpyridine, 5,6,7,8-tetrahydroquinoline, 2-methylpyrazine, and 5-methylpyrazine.

[0011] The concentration of the pyridine-based compound in the electroplating bath containing the pyridine-based compound is preferably 0.18 to 938 mmol / L, and particularly preferably 0.88 to 368 mmol / L.

[0012] The bath temperature of the electroplating bath containing the pyridine compound is preferably 5 to 90°C, and particularly preferably 25 to 45°C.

[0013] The electroplating bath containing the pyridine-based compound may contain, as compounds that provide conductivity and buffering properties, inorganic acids, organic acids, alkali salts thereof, organic complexing agents, alkali salts thereof, organic amines, organic polyamines, etc.

[0014] The electroplating bath containing the pyridine-based compound may further contain, as a film stabilizer or a film adhesion enhancer, low molecular weight compounds such as compounds having a phenolic hydroxyl group or phenolic acid salts, polymeric compounds having these in their skeletons, and polymeric compounds known as polyphenols such as tannin, tannic acid, and catechin.

[0015] In the electroplating bath containing the pyridine-based compound, it is preferable to employ cathodic electrolysis. This makes it possible to form a highly durable coating. The current density during cathodic electrolysis is preferably 0.2 to 60 A / dm2, and more preferably 1 to 10 A / dm2. This makes it possible to form a coating at a relatively low current density.

[0016] In addition, in the electroplating bath containing the above pyridine-based compound, it is possible to employ an electrolysis method in which anodic electrolysis and cathodic electrolysis are alternately repeated, i.e., the so-called PR electrolysis method, rather than cathodic electrolysis. When employing the PR electrolysis method, it is preferable that the current density during cathodic electrolysis is 0.2 to 60 A / dm2 and the current density during anodic electrolysis is 0 to 30 A / dm2, and it is particularly preferable that the current density during cathodic electrolysis is 1 to 10 A / dm2 and the current density during anodic electrolysis is 0 to 10 A / dm2. Furthermore, it is preferable that the cathodic electrolysis time is 0.1 to 10 seconds and the anodic electrolysis time is 0.1 to 10 seconds, and the ratio of the cathodic electrolysis time to the anodic electrolysis time is preferably cathodic electrolysis time:anodic electrolysis time = 1:0.1 to 1:1.

[0017] It is also preferable to perform a nickel undercoat plating before forming a coating using the electroplating bath containing the pyridine compound. This allows the coating to be properly formed using the electroplating bath containing the pyridine compound and improves adhesion. The cathode current density during the nickel undercoat plating is preferably 0.5 to 30 A / dm2, and more preferably 1 to 15 A / dm2. The bath temperature is preferably 30 to 60°C.

[0018] The coating formed using an electroplating bath containing the pyridine-based compound only needs to contain at least Ni, and by adjusting the metal ions added, it is possible to include single metals other than Ni, such as Cu, Co, Mn, Fe, In, Ir, Pt, Sn, Pd, Ag, Ru, and Rh, or alloys of two or more of these elements containing Ni. Furthermore, the coating can also include fine particles of metal oxides and sulfides of Mo, W, Zr, Si, Ce, V, Al, Ni, Cu, Co, Mn, Fe, In, Sn, Pd, Ag, Ru, and Rh, carbon bodies such as carbon nanotubes, carbon nanofibers, and carbon black, alkali metal compounds, alkaline earth metal compounds, and the like.

[0019] The "hydrogen generation promoting member" according to the present invention is produced by forming a plating film on the surface of a substrate using an electroplating bath containing the pyridine-based compound. Then, by immersing the hydrogen generation promoting member in an alkaline solution while electrically contacting the member with a metal having a corrosion potential lower than that of nickel, the metal is dissolved, thereby generating high-purity hydrogen.

[0020] The electrical contact between the hydrogen generation promotion member and the metal having a corrosion potential lower than that of nickel may be achieved by directly contacting the hydrogen generation promotion member with the metal, or by connecting the hydrogen generation promotion member with a conductive wire or the like to achieve indirect contact. When the hydrogen generation promotion member and the metal are in indirect contact, they may be contacted via a variable resistor. This allows the current flowing between the hydrogen generation promotion member and the metal to be adjusted, thereby adjusting the amount of hydrogen generated.

[0021] The ratio of the surface area of ​​the hydrogen generation promotion member immersed in the alkaline solution to the surface area of ​​the metal having a corrosion potential more base than nickel is preferably 0.1:1 to 1:0.1, and particularly preferably 1:1. That is, the ratio of the surface area of ​​the hydrogen generation promotion member to the surface area of ​​the metal is preferably 0.1 to 10, and particularly preferably 1. Note that a metal having a corrosion potential more base than nickel dissolves when immersed in an alkaline solution, and the surface area of ​​the metal decreases with the lapse of immersion time. Therefore, considering that the ratio of the surface area of ​​the hydrogen generation promotion member to the surface area of ​​the metal increases with the lapse of immersion time, the value of the ratio (0.1 to 10) is the value at the beginning of immersion, and the ratio during immersion is preferably 0.1 or more.

[0022] Metals having a corrosion potential lower than that of nickel include Al, Zn, Mg, etc., with Al and Zn being particularly preferred.

[0023] The hydrogen generation promoting member to be immersed in the alkaline solution and the metal having a corrosion potential lower than that of nickel may each take various shapes, such as a plate shape, a lump shape, a granular shape, or a shavings shape.

[0024] Examples of alkaline solutions include sodium hydroxide solution, potassium hydroxide solution, calcium hydroxide solution, and barium hydroxide solution. If the alkaline solution is a sodium hydroxide solution, the sodium hydroxide concentration is preferably 5 to 400 g / L, and more preferably 100 g / L. If the alkaline solution is a potassium hydroxide solution, the potassium hydroxide concentration is preferably 7 to 561 g / L, and more preferably 140 g / L.

[0025] The temperature of the alkaline solution is preferably 15 to 40°C, and particularly preferably 20°C.

[0026] Furthermore, when the hydrogen generation promotion member and a metal having a corrosion potential lower than nickel are immersed in an alkaline solution in a connected state, hydrogen can be generated favorably by stirring the alkaline solution. However, in consideration of the power consumption required for stirring, it is preferable to immerse the hydrogen generation promotion member and the metal in a connected state in the alkaline solution without stirring the alkaline solution. [Example]

[0027] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples and can be practiced in various forms with various modifications and improvements based on the knowledge of those skilled in the art.

[0028] An acidic electroplating bath for producing a hydrogen generation promoting member was prepared from the raw materials having the composition shown in Figure 1. Details of each raw material are as follows. Nickel chloride hexahydrate: Fujifilm Wako Pure Chemical Industries, Ltd. 35% hydrochloric acid: Toagosei Co., Ltd. Pyridine compounds: 1-benzyl-3-carboxylate pyridinium sodium chloride

[0029] Before forming the electroplating film using the acidic electroplating bath, the substrate is subjected to a nickel undercoat to enhance the adhesion of the film. The substrate used in the acidic electroplating bath is a plate-shaped SPCC-SD material (manufactured by Engineering Test Services Co., Ltd.) and granular Strong Steel Shot NB-280 (manufactured by Nitchu Co., Ltd.: cast steel shot, φ2.8 mm balls).

[0030] The plating bath for the base nickel is prepared using the ingredients of the plating bath composition shown in Figure 2. Details of each ingredient in Figure 2 are as follows: Nickel chloride hexahydrate: Fujifilm Wako Pure Chemical Industries, Ltd. 35% hydrochloric acid: Toagosei Co., Ltd.

[0031] The plating conditions for the nickel base are as follows: Cathode current density: 1A / dm2 Bath temperature: 35℃ Processing time: 70 minutes Anode: Ni material Liquid circulation: Stirrer stirring (rotation speed: 500 rpm) (stirring bar size: φ8 x 30 mm)

[0032] When the nickel base plating is performed under the above conditions, a nickel coating (hereinafter referred to as the "nickel base coating") having a thickness of 5 μm is formed on the surface of the substrate. Then, cathodic electroplating is performed on the substrate on which the nickel base coating has been formed, using the acid electroplating bath shown in FIG. 1. The electroplating conditions at this time are as follows: Liquid pH: less than 0.1 Anode: Ni material or insoluble anode Liquid circulation: Stirrer stirring (rotation speed: 500 rpm) (stirring bar size: φ8 x 30 mm) The cathode current density (A / dm2), bath temperature (°C), and treatment time (min) are listed in the plating conditions in Figure 1.

[0033] By performing electroplating under the above conditions, a nickel film (hereinafter referred to as a "hydrogen generation-promoting film") is formed on the substrate on which the underlying nickel film has been formed. That is, an underlying nickel film is formed on the surface of the substrate, and the hydrogen generation-promoting film is formed on the surface of the underlying nickel film. The film thickness (μm) of the hydrogen generation-promoting film thus formed was measured. The measured film thickness (μm) of the hydrogen generation-promoting film is shown in FIG. 1.

[0034] The composition of the hydrogen generation promoting coating of Example 1 formed as described above was measured using a scanning electron microscope (JSM-IT300, manufactured by JEOL Ltd.) and an energy dispersive X-ray analyzer (EX-37001, manufactured by JEOL Ltd.). The composition is shown below. Composition of the hydrogen generation promoting film Ni: 93.04 wt% C: 3.36 wt% O: 3.61 wt%

[0035] Then, a member on which a hydrogen generation promoting film was formed by the above-described method (hereinafter referred to as the "hydrogen generation promotion member") was immersed in a sodium hydroxide solution while being in electrical contact with aluminum, and the amount of hydrogen generation was measured. Specifically, as shown in FIG. 9 , a plate-shaped aluminum plate 10 (surface area: 0.75 dm²) and a plate-shaped hydrogen generation promotion member 12 (0.75 dm²) were immersed in a sodium hydroxide solution 14 while being in direct contact with each other. That is, the plate-shaped aluminum plate 10 and the plate-shaped hydrogen generation promotion member 12 were immersed in a sodium hydroxide solution 14 while being in direct contact with each other, under the condition that the ratio of the surface area of ​​the aluminum plate to the surface area of ​​the hydrogen generation promotion member was 1. The aluminum plate 10 and the hydrogen generation promotion member 12 were fixed with a fixing member 16 such as a clip. The temperature of the sodium hydroxide solution was 20°C, and the sodium hydroxide solution was not stirred. The amount of hydrogen generated when the aluminum plate 10 and the hydrogen generation promotion member 12 were immersed in each of seven sodium hydroxide solutions with sodium hydroxide concentrations of 5 g / L, 10 g / L, 50 g / L, 100 g / L, 200 g / L, 300 g / L, and 400 g / L was measured. The generated hydrogen was collected by water displacement, and the amount of collected hydrogen per unit time was measured as the hydrogen generation rate (ml / min). The amount of hydrogen generated when the aluminum plate and the hydrogen generation promotion member were immersed in the sodium hydroxide solution in a state of contact with each other (hereinafter referred to as the "hydrogen generation rate when the promotion member is used") is shown in Figure 3. In addition, as a blank test, the amount of hydrogen generated (ml / min) when only an aluminum plate was immersed in each of the seven types of sodium hydroxide solution was also measured. The amount of hydrogen generated in the blank test is also shown in Figure 3. Then, the ratio of the amount of hydrogen generated when the accelerator member was used to the amount of hydrogen generated in the blank test (hereinafter referred to as "hydrogen generation ratio") was calculated, and this hydrogen generation ratio is also shown in FIG.

[0036] The amount of hydrogen generated was also measured when an aluminum plate and a hydrogen generation promotion member were immersed in each of six types of sodium hydroxide solutions with liquid temperatures of 15°C, 20°C, 25°C, 30°C, 35°C, and 40°C while in contact with each other. The amount of hydrogen generated when the promotion member was used, measured for each of the six types of sodium hydroxide solutions, is shown in Figure 4. In each of the six types of sodium hydroxide solutions, the sodium hydroxide concentration was 100 g / L, and the ratio of the surface area of ​​the hydrogen generation promotion member to the surface area of ​​the aluminum plate was 1. In addition, each of the six types of sodium hydroxide solutions was unstirred. In addition, as a blank test, the amount of hydrogen generated (ml / min) when only an aluminum plate was immersed in each of the six types of sodium hydroxide solution was also measured. The amount of hydrogen generated in the blank test is also shown in Figure 4. The hydrogen generation ratio of the amount of hydrogen generated when the accelerator was used to the amount of hydrogen generated in the blank test was calculated, and this hydrogen generation ratio is also shown in FIG.

[0037] In addition, the ratio of the surface area of ​​the hydrogen generation promotion member to the surface area of ​​the aluminum plate was changed, and the amount of hydrogen generated when the aluminum plate and the hydrogen generation promotion member were immersed in a state of contact was also measured. Specifically, the amount of hydrogen generated was measured when a plate-shaped aluminum plate (surface area 0.075 dm2) and a plate-shaped hydrogen generation promotion member (0.75 dm2) were immersed in a sodium hydroxide solution in a state of direct contact. That is, the amount of hydrogen generated was measured when a plate-shaped aluminum plate and a plate-shaped hydrogen generation promotion member were immersed in a sodium hydroxide solution in a state of contact, under the condition that the ratio of the surface area of ​​the hydrogen generation promotion member to the surface area of ​​the aluminum plate was 10. In addition, the amount of hydrogen generated was measured when a plate-shaped aluminum plate (surface area 0.75 dm2) and a plate-shaped hydrogen generation promotion member (0.075 dm2) were immersed in a sodium hydroxide solution in a state of direct contact. Specifically, the ratio of the surface area of ​​the hydrogen generation promotion member to the surface area of ​​the aluminum plate was 0.1, and the amount of hydrogen generated was measured when a plate-shaped aluminum plate and a plate-shaped hydrogen generation promotion member were in contact with each other and immersed in a sodium hydroxide solution. The amount of hydrogen generated was also measured when a plate-shaped aluminum plate (surface area 0.75 dm2) and a plate-shaped hydrogen generation promotion member (0.75 dm2) were in direct contact with each other and immersed in a sodium hydroxide solution. The ratio of the surface area of ​​the hydrogen generation promotion member to the surface area of ​​the aluminum plate was 1, and the amount of hydrogen generated was measured when a plate-shaped aluminum plate and a plate-shaped hydrogen generation promotion member were in contact with each other and immersed in a sodium hydroxide solution. The concentration of the sodium hydroxide solution was 100 g / L, and the temperature of the sodium hydroxide solution was 20°C. The sodium hydroxide solution was not stirred. The amounts of hydrogen generated during use of the promotion member measured under the conditions of a surface area ratio of 10, 1, and 0.1 are shown in FIG. 5. As a blank test, the amount of hydrogen generated (ml / min) was also measured when the aluminum plate alone was immersed in a sodium hydroxide solution with different surface areas. The amount of hydrogen generated in the blank test is also shown in Figure 5. Then, the hydrogen generation ratio of the amount of hydrogen generated when the accelerator was used to the amount of hydrogen generated in the blank test was calculated, and this hydrogen generation ratio is also shown in FIG.

[0038] As described above, efficient hydrogen generation is achieved by immersing a plate-shaped aluminum plate and a plate-shaped hydrogen generation promotion member in contact with each other in a sodium hydroxide solution. Specifically, as shown in FIG. 3 , the hydrogen generation ratio is 1.2 or higher at any sodium hydroxide solution concentration range of 5 to 400 g / L. That is, at any sodium hydroxide solution concentration range of 5 to 400 g / L, hydrogen generation is 1.2 times or higher by immersing an aluminum plate in contact with a hydrogen generation promotion member in a sodium hydroxide solution compared to immersing only an aluminum plate in a sodium hydroxide solution. In particular, when the sodium hydroxide solution concentration is in the range of 50 to 300 g / L, the hydrogen generation ratio is 1.3 or higher, enabling efficient hydrogen generation. Furthermore, considering the hydrogen generation ratio, the amount of hydrogen generated per unit time, and the duration for which hydrogen can be continuously generated, the concentration of the sodium hydroxide solution is preferably 100 to 300 g / L, and more preferably 100 g / L.

[0039] Furthermore, as shown in Figure 4, the hydrogen generation ratio is 1.1 or more regardless of the temperature range of the sodium hydroxide solution from 15 to 40°C. In other words, regardless of the temperature range of the sodium hydroxide solution from 15 to 40 g / L, hydrogen can be generated more efficiently by bringing the aluminum plate into contact with the hydrogen generation promotion member and immersing it in the sodium hydroxide solution compared to immersing only the aluminum plate in the sodium hydroxide solution. In particular, when the temperature of the sodium hydroxide solution is 20°C, the hydrogen generation ratio is 1.3, allowing for efficient hydrogen generation.

[0040] 5, the hydrogen generation ratio is 1.1 or more regardless of the ratio of the surface area of ​​the hydrogen generation promotion member to the surface area of ​​the aluminum plate being in a range of 0.1 to 10. In other words, regardless of the ratio of the surface area of ​​the hydrogen generation promotion member to the surface area of ​​the aluminum plate being in a range of 0.1 to 10, hydrogen can be generated more efficiently by bringing the aluminum plate and the hydrogen generation promotion member into contact with each other and immersing them in a sodium hydroxide solution compared to immersing only the aluminum plate in a sodium hydroxide solution. In particular, when the ratio of the surface area of ​​the hydrogen generation promotion member to the surface area of ​​the aluminum plate is 1, the hydrogen generation ratio is 1.3, allowing hydrogen to be generated efficiently.

[0041] Furthermore, hydrogen can be efficiently generated by directly contacting a metal other than aluminum with the hydrogen generation promotion member and immersing the member in a sodium hydroxide solution. Specifically, a plate-shaped zinc plate (surface area: 0.75 dm²) and a plate-shaped hydrogen generation promotion member (0.75 dm²) were immersed in a sodium hydroxide solution while in direct contact with each other. That is, the plate-shaped zinc plate and the plate-shaped hydrogen generation promotion member were immersed in a sodium hydroxide solution while in direct contact with each other, with the ratio of the surface area of ​​the zinc plate to the surface area of ​​the hydrogen generation promotion member being 1. The concentration of the sodium hydroxide solution was 100 g / L, and the temperature of the sodium hydroxide solution was 20°C. The sodium hydroxide solution was not stirred. The amount of hydrogen generated during use of the promotion member was measured when the zinc plate and the hydrogen generation promotion member were in contact with each other and immersed in a sodium hydroxide solution. The amount of hydrogen generated during use of the promotion member is shown in Figure 6. As a blank test, the amount of hydrogen generated (ml / min) when only the zinc plate was immersed in the sodium hydroxide solution was also measured. In this case, almost no hydrogen was generated, so the amount of hydrogen generated could not be measured. Therefore, it was not possible to calculate the hydrogen generation rate.

[0042] Thus, hydrogen can be efficiently generated by immersing a plate-shaped zinc plate and a plate-shaped hydrogen generation promotion member in contact with each other in a sodium hydroxide solution. In other words, hydrogen cannot be generated by immersing only a zinc plate in a sodium hydroxide solution. However, hydrogen can be generated by immersing a plate-shaped zinc plate and a plate-shaped hydrogen generation promotion member in contact with each other in a sodium hydroxide solution. This shows that hydrogen can be efficiently generated by electrically connecting a metal, such as aluminum or zinc, whose corrosion potential in an alkaline solution is lower than that of nickel to a hydrogen generation promotion member and immersing the metal in a sodium hydroxide solution.

[0043] Furthermore, hydrogen can be efficiently generated regardless of the shape of the metal in contact with the hydrogen generation promotion member. Specifically, zinc particles (manufactured by Toho Zinc Co., Ltd.) in granular form (surface area: 2.2 dm²) were directly contacted with a hydrogen generation promotion member in granular form (surface area: 2.5 dm²) and immersed in a sodium hydroxide solution. Specifically, the zinc particles and the hydrogen generation promotion member in granular form were directly contacted and immersed in a sodium hydroxide solution under the condition that the ratio of the surface area of ​​the zinc particles to the surface area of ​​the hydrogen generation promotion member was 1.14. The concentration of the sodium hydroxide solution was 100 g / L, and the temperature of the sodium hydroxide solution was 20°C. The sodium hydroxide solution was not stirred. The amount of hydrogen generated during use of the promotion member was measured when the zinc particles and the hydrogen generation promotion member were in contact and immersed in a sodium hydroxide solution. The amount of hydrogen generated during use of the promotion member is shown in Figure 7. As a blank test, the amount of hydrogen generated (ml / min) when zinc particles alone were immersed in a sodium hydroxide solution was also measured. Since almost no hydrogen was generated, the amount of hydrogen generated could not be measured. Therefore, it was not possible to calculate the hydrogen generation rate.

[0044] In this way, hydrogen can be efficiently generated by immersing a granular zinc plate in a sodium hydroxide solution while the plate is in contact with the hydrogen generation promotion member. In other words, hydrogen cannot be generated by immersing only zinc granules in a sodium hydroxide solution, but hydrogen can be generated by immersing the plate in a sodium hydroxide solution while the zinc granules are in contact with the hydrogen generation promotion member. This shows that hydrogen can be efficiently generated regardless of the shape of the metal that is brought into contact with the hydrogen generation promotion member.

[0045] Furthermore, hydrogen can be efficiently generated by immersing aluminum in contact with a hydrogen generation promotion member in an alkaline solution other than a sodium hydroxide solution. Specifically, a plate-shaped aluminum plate (surface area: 0.75 dm²) and a plate-shaped hydrogen generation promotion member (surface area: 0.75 dm²) were immersed in a potassium hydroxide solution while in direct contact with each other. The potassium hydroxide solution had a concentration of 100 g / L and a temperature of 20°C. The potassium hydroxide solution was not stirred. The amount of hydrogen generated when the promotion member was in use was measured when the aluminum plate and the hydrogen generation promotion member were in contact with each other and immersed in a potassium hydroxide solution. The amount of hydrogen generated when the promotion member was in use is shown in Figure 8. As a blank test, the amount of hydrogen generated (ml / min) when only the aluminum plate was immersed in the potassium hydroxide solution was also measured. The amount of hydrogen generated in the blank test is also shown in Figure 8. Then, the hydrogen generation ratio of the amount of hydrogen generated when the accelerator was used to the amount of hydrogen generated in the blank test was calculated, and this hydrogen generation ratio is also shown in FIG.

[0046] Thus, efficient hydrogen generation is possible by immersing an aluminum plate in a potassium hydroxide solution while the aluminum plate is in contact with the hydrogen generation promotion member. In other words, by immersing an aluminum plate in a potassium hydroxide solution while the aluminum plate is in contact with the hydrogen generation promotion member, the hydrogen generation ratio becomes 1.3, which means that hydrogen can be generated 1.3 times more efficiently than when only the aluminum plate is immersed in a potassium hydroxide solution. This demonstrates that efficient hydrogen generation is possible by immersing an aluminum plate in an alkaline solution such as a sodium hydroxide solution or a potassium hydroxide solution while the aluminum plate is electrically connected to the hydrogen generation promotion member.

[0047] In this way, hydrogen can be efficiently generated by electrically connecting the hydrogen generation promotion member and a metal having a corrosion potential lower than nickel in an alkaline solution and immersing the member in the alkaline solution. In this case, as shown in FIG. 9, hydrogen can be generated simply by immersing the hydrogen generation promotion member and the metal in the alkaline solution while electrically connecting them. Therefore, hydrogen can be generated using a simple and uncomplicated hydrogen production device. Furthermore, hydrogen can be generated without using electricity, so low-cost hydrogen can be obtained. In particular, as described above, alkaline solutions such as sodium hydroxide can efficiently generate hydrogen even without stirring, so that the electricity required for stirring is not required, and low-cost hydrogen can be obtained.

[0048] Furthermore, the hydrogen generated by the above method was collected by water displacement, and the purity of the collected hydrogen was measured using a gas chromatograph (GC-2014: manufactured by Shimadzu Corporation), which revealed that the purity of the hydrogen was 98.3%. In this way, highly pure hydrogen can be obtained by generating hydrogen by electrically connecting the hydrogen generation promotion member to a metal whose corrosion potential in alkaline solution is lower than that of nickel and immersing it in alkaline solution.

Claims

1. A hydrogen generation method comprising: using an acidic electroplating bath containing a pyridine-based compound and nickel, electrically connecting a hydrogen generation promotion member having an electroplating film formed on the surface of a workpiece having a metal surface to a metal having a corrosion potential lower than nickel in the alkaline solution, and immersing the connected member in the alkaline solution to generate hydrogen.

2. 2. The method for generating hydrogen according to claim 1, wherein the alkaline solution contains sodium hydroxide.

3. 3. The method for generating hydrogen according to claim 2, wherein the alkaline solution contains 5 to 400 g / L of sodium hydroxide.

4. 2. The method for generating hydrogen according to claim 1, wherein the alkaline solution contains potassium hydroxide.

5. 5. The method for generating hydrogen according to claim 4, wherein the alkaline solution contains 7 to 561 g / L of potassium hydroxide.

6. 6. The method for generating hydrogen according to claim 1, wherein the metal less noble than nickel is aluminum.

7. 7. The method for generating hydrogen according to claim 1, wherein the ratio of the surface area of ​​the hydrogen generation promoting member to the surface area of ​​the metal less noble than nickel is 0.1 or more.

8. A method for producing a hydrogen generation promotion member that generates hydrogen when immersed in an alkaline solution while electrically connected to a metal having a corrosion potential lower than nickel in the alkaline solution, comprising: A manufacturing method for producing a hydrogen generation promoting member by forming an electroplating film on the surface of a workpiece having a metal surface using an acidic electroplating bath containing a pyridine-based compound and nickel.

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