JP2017095746A - Hydrogen generator and hot-water feed system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydrogen generator capable of production with a simple structure suited to installation and maintenance and also at a low cost.SOLUTION: Provided is a hydrogen generator comprising: an electrode part 2A electrolyzing water, provided with a hydrogen pole 22 and an oxygen pole 23 so as to hold both the sides of a PEM membrane 24 in a sealed container; and a power source part 3 applying d.c. voltage to a space between the hydrogen pole 22 and the oxygen pole 23 in the electrode part 2A, in which an electrode material for water electrolysis containing no platinum group elements is used as a hydrogen pole catalyst layer in the hydrogen pole 22 or an oxygen pole catalyst layer in the oxygen pole 23. The electrode material for water electrolysis is made of a molded body essentially consisting of Fe or Ni, and being a molded body at least including, as metallic material, Fe or Ni and a plurality of different transition metals belonging to 3d transition metals.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a hydrogen generator and a hot water supply system.

  Using hydrogen generators that generate hydrogen, hydrogen is mixed with water and dissolved in the form of fine bubbles and used for beverages, and used for hot water for bathing and the like.

  It should be noted that in a bathroom apparatus using hydrogen water, a hydrogen water bathing mechanism (hydrogen gas cylinder provided outside the bathroom, an air discharge unit disposed in the bathtub, a hydrogen gas cylinder, which supplies hydrogen and uses hot water as hydrogen water) A hydrogen supply bath mechanism for supplying hydrogen water bath containing hydrogen or a supply pipe connecting the gas release section and a shutoff valve mechanism provided in the supply pipe (hydrogen supply path) or hydrogen Provided with a predetermined exhaust ventilation mechanism, a hydrogen sensor in the bathroom, and a shutoff valve mechanism that shuts off the hydrogen supply path or the bath water supply path in the hydrogen water bathing mechanism based on the detection value of the hydrogen sensor in the bathroom It is known that the above is provided (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 2008-5973

  Conventional hot water supply equipment is a type equipped with a hydrogen gas tank, and it takes time to supply hydrogen. In addition, the maintenance cost of the hydrogen gas tank to be stored is high, so it is not suitable for general households.

  On the other hand, if the hydrogen generator can be manufactured at low cost and can be installed in a hot water supply facility, hydrogen water can be easily used at home. The hydrogen generator and hot water supply system as described above are desired.

  Therefore, the problem to be solved by the present invention is to provide a hydrogen generator and a hot water supply system that can be manufactured at a low cost with a simple structure suitable for installation and maintenance.

  In order to solve the above problems, a hydrogen generator according to the present invention is a hydrogen generator capable of supplying water by electrolyzing water. The hydrogen generation device is formed of a sealed container capable of discharging hydrogen, and an electrode unit for electrolyzing water is provided so that a hydrogen electrode and an oxygen electrode sandwich both sides of the electrolyte membrane in the sealed container. And a power supply unit that applies a DC voltage between the hydrogen electrode and the oxygen electrode in the electrode unit. In the water electrolysis electrode material used as the hydrogen electrode catalyst layer in the hydrogen electrode or the oxygen electrode catalyst layer in the oxygen electrode, for water electrolysis that does not contain platinum group elements of Ru, Rh, Pd, Os, Ir, and Pt. The electrode material for water electrolysis is a molded body mainly composed of Fe or Ni, and contains at least Fe or Ni and a plurality of different transition metals belonging to a 3d transition metal as a metal material. The molded body is made of a mixture containing each powder of the metal material, and the water and hydrogen gas or oxygen gas generated by electrolyzing the water permeate the molded body. The main feature is to have voids dispersed in the molded body as much as possible.

  Further, in the hydrogen generator according to the present invention, the plurality of different transition metals include at least one of Fe, Ni, Mn, Cr, or Ti belonging to a 3d transition element, and the compact includes The main feature is that the metal material other than the transition metal to be contained includes any one of Cu, Zn, Al, or Mg, which has a higher electrical conductivity than the transition metal contained.

  Furthermore, the hydrogen generator according to the present invention is characterized in that the plurality of different transition metals include at least Ni and Fe, Ni and Cu, or Fe and Cu.

  Furthermore, in the hydrogen generator according to the present invention, the composition ratio of the metal material in the molded body is 1 to 3 mass% of Mg or 2 to 2 mass of Zn when the mass of the molded body is 100 mass%. The main feature is that it contains at least 3% by mass or 5-6% by mass of Al, and contains Ni, Fe, and Cr totaling 100% by mass, which is obtained by subtracting the mass% of the contained metal.

  In addition, the hydrogen generator according to the present invention is characterized in that the porosity of the molded body is in a range of 20% to 40% with respect to the volume of the molded body.

  Furthermore, the water electrolysis electrode material is characterized in that the hydrogen electrode catalyst layer or the oxygen electrode catalyst layer further contains a titanium oxide material.

  Furthermore, the water electrolysis electrode material is characterized in that the electrode part further includes ultraviolet irradiation means for irradiating the hydrogen electrode or the oxygen electrode with ultraviolet rays.

  Moreover, in order to solve the said subject, the hot water supply system which concerns on this invention is based on the said hydrogen production | generation apparatus in any one of the above, the hot water supply apparatus which can supply water or hot water to hot-water supply piping, and the said hydrogen production | generation apparatus. A discharge pump for discharging hydrogen gas, and mixing the hydrogen gas discharged from the hydrogen generator with water or hot water supplied from the hot water supply device and returning the mixed water to the hot water supply pipe by the discharge pump. Main features.

  The hydrogen generator and hot water supply system according to the present invention can be manufactured at a low cost with a simple structure suitable for installation and maintenance.

The block diagram which shows an example of a structure of the hydrogen generator of 1st Embodiment which concerns on this invention The figure which shows an example of the structure of the electrode part used for the hydrogen generator of FIG. The figure which shows an example of the other structure of the electrode part used for the hydrogen generator of FIG. The figure which shows an example of the structure of the hydrogen electrode unit used for the electrode part of FIG. Diagram showing prototype water electrolysis electrode material Table showing the outline of the prototype electrode materials for water electrolysis The figure which shows an example of another structure of the electrode part used for the hydrogen generator of FIG. The figure which shows the Example of a hot-water supply system

  Hereinafter, an embodiment of a hydrogen generator according to the present invention will be specifically described with reference to the drawings. Here, the same or similar parts are denoted by common reference numerals, and redundant description is omitted. The following embodiment described here will be described by taking an example of a hydrogen generator attached to a hot water supply facility.

[First Embodiment]
FIG. 1 is a block diagram illustrating an example of the configuration of the hydrogen generator 1 according to the first embodiment.
The hydrogen generator 1 of this embodiment generates hydrogen and oxygen by electrolyzing water. The hydrogen generator 1 can supply hydrogen to a water / hot water supply piping route of the hot water supply apparatus. For this purpose, as shown in FIG. 1, the hydrogen generator 1 includes an electrode unit 2, a distilled water tank 11, a gas-liquid separator 12, a drying filter 13, a power supply unit 3, a control unit 4, And a display unit 5.

  The electrode unit 2 is composed of a hydrogen electrode 22, an oxygen electrode 23, and a PEM film 24 mainly made of an electrode material for water electrolysis, as will be described later (FIG. 2 etc.). The electrode part 2 is formed so as to have a sealed container provided with at least a water supply port and a discharge port for discharging hydrogen gas and oxygen gas.

  The electrode unit 2 is formed of a sealed container capable of discharging generated hydrogen, and the hydrogen electrode 22 and the oxygen electrode 23 are provided so as to sandwich both sides of the electrolyte membrane (PEM film 24) in the sealed container. Yes. The sealed container is made of, for example, a non-conductive material. Or even if it is mainly formed of a metal material, the inside of the container is covered with a non-conductive sheet.

  The electrode unit 2 electrolyzes the supplied or replenished water to generate hydrogen and oxygen. In the case of a single cell unit configuration, for example, the electrode unit 2 can electrolyze water at an interelectrode applied voltage of 1.6 V or higher.

  As shown in FIG. 2, the power supply unit 3 applies a DC voltage between the hydrogen electrode 22 and the oxygen electrode 23 in the electrode unit 2 to supply DC electricity. In addition, the power supply unit 3 supplies electricity at a necessary voltage level to the control unit 4, the display unit 5, sensors / instruments, and the like shown in FIG. For example, the power supply unit 3 is connected to a commercial power source (for example, AC 100 V) or the like drawn from the outside, and converts the commercial power source into electricity at a necessary DC level of the hydrogen generator 1.

  The distilled water tank 11 stores distilled water in order to supply the electrode unit 2 with water for electrolysis. The distilled water tank 11 is connected so that distilled water can be supplied to the electrode part 2. Further, the distilled water tank 11 is provided with a flow path so as to be able to receive the water circulated and returned from the gas-liquid separator 12 and the electrode unit 2.

  The gas-liquid separator 12 separates water and hydrogen gas from water containing hydrogen gas discharged from the electrode unit 2. After separating water and hydrogen gas, the gas-liquid separator 12 returns the water to the distilled water tank 11 and discharges the hydrogen gas to the dry filter 13.

  The drying filter 13 passes the hydrogen gas containing moisture discharged from the gas-liquid separator 12, removes the moisture with a filter while allowing the hydrogen gas to pass, and dries it. The drying filter 13 discharges the dried hydrogen gas through the hydrogen discharge port of the hydrogen generator 1. For example, in the dry filter 13, a filter coated with a medicine is used, and it is possible to know the filter replacement time from the color change. As a result, the maintenance replacement timing can be easily recognized visually.

  The hydrogen meter 114 is provided at the hydrogen outlet. The hydrogen meter 114 measures the flow rate of hydrogen gas passing through the hydrogen discharge port. The hydrogen meter 114 sends the measurement data to the control unit 4. For example, the control unit 4 converts the production amount of hydrogen gas based on the measurement data.

  The liquid level sensor 111 measures the level of distilled water stored in the distilled water tank 11. Thereby, the remaining amount of distilled water can be detected. The liquid level sensor 111 sends measurement data to the control unit 4.

  The electrode current detection sensor 112 measures the current flowing through the electrode unit 2. The electrode current detection sensor 112 sends measurement data to the control unit 4.

  The hydrogen pressure sensor 113 is provided at the discharge port of the drying filter 13 and measures the pressure of the hydrogen gas discharged from the drying filter 13. The hydrogen pressure sensor 113 sends measurement data to the control unit 4.

  The control unit 4 sequentially collects measurement data measured from various sensors, and monitors each state (hydrogen gas amount, distilled water remaining amount, electrode current, etc.) based on the collected measurement data. For example, the control unit 4 is provided with a protection function for stopping the supply of electricity from the power supply unit 3 when the electrode current detection sensor 112 detects an overcurrent. The control unit 4 includes a memory, a CPU, and the like, and the monitoring / protection / control operation process is executed by a program in which a monitoring / protection / control function is incorporated.

  The display unit 5 is a lamp display, instrument display, liquid crystal data display, etc. so as to be able to display the power ON / OFF state, warning (overcurrent alarm, etc.) state of the power supply unit 3 and various measurement data as described above. Is displayed.

  As described above, the hydrogen generator 1 of the present embodiment can be configured with very simple parts. Moreover, since these parts have a long replacement part life, the hydrogen generator 1 can easily perform maintenance such as repair, replacement, and inspection.

  The normal maintenance performed by the user is to replenish the hydrogen generator 1 with distilled water, and does not require complicated operations and operations.

  Moreover, since the hydrogen generator 1 of this embodiment produces | generates hydrogen by electrolysis of water, it can produce | generate high purity hydrogen. Furthermore, hydrogen can be produced at the same time the apparatus is started.

  Further, since the liquid level sensor 111, the electrode current detection sensor 112, the hydrogen pressure sensor 113, and the hydrogen meter 114 can be provided on the main body side of the hydrogen generator 1, the water level of the hydrogen gas increased in pressure and stored. Detecting a decrease or the like. The control unit 4 can monitor the detection of these abnormalities, etc., and can stop the voltage application of the power supply unit 3 to protect the device and automatically stop the hydrogen generation. Thereby, it can apply to a general household as an apparatus excellent in safety | security.

[Second Embodiment]
A configuration example of the electrode unit 2 is shown as the hydrogen generator 1 of the second embodiment. Here, FIG. 2 shows an example of the structure of the electrode part 2 (electrode part 2A) used in the hydrogen generator 1 of FIG. 1, and FIG. Part 2B).

  The electrode part 2A shown in FIG. 2 is an example of a solid polymer membrane type water electrolysis electrode. As shown in FIG. 2, the electrode part 2A is a sealed container including a hydrogen electrode 22, an oxygen electrode 23, and a PEM film 24 in the container. The sealed container is provided with a hydrogen storage unit 25, a water storage unit 26, a hydrogen discharge connection unit 31, an oxygen discharge connection unit 33, a water discharge unit 32, and a water supply connection unit 34. That is, the structure is such that water can be supplied and water, hydrogen gas, and oxygen gas can be discharged from inside and outside the container.

  The sealed container is partitioned by the hydrogen electrode 22 side and the oxygen electrode 23 side. In the sealed container, a hydrogen discharge connection portion 31 is provided above the hydrogen storage portion 25 in the compartment on the hydrogen electrode 22 side (on the upper side with respect to the direction of gravity), and the water storage portion in the compartment on the oxygen electrode 23 side. An oxygen discharge connecting portion 33 is provided at the upper portion of 26. Thereby, the generated hydrogen gas and oxygen gas are easily discharged from the electrode portion 2A.

The oxygen electrode 23 is an anode made of an electrode material for water electrolysis having an oxygen electrode catalyst layer not containing a platinum group element (Ru, Rh, Pd, Os, Ir, Pt). On the oxygen electrode 23 side, for example, an oxygen discharge connection portion 33 connected to an external discharge port, and a water storage portion 26 for storing oxygen generated at the oxygen electrode 23 and water supplied from the water supply connection portion 34 are provided. Thus, oxygen (O ₂ ) is discharged.

In the vicinity of the oxygen electrode 23 on the PEM film 24 side, water (H ₂ O) supplied from the water supply connection part 34 and accumulated in the water storage part 26 is electrolyzed, and hydrogen ions (H ⁺ ) and electrons ( e ⁻ ) and oxygen (O ₂ ) are generated. The generated hydrogen ions move to the hydrogen electrode 22 through the PEM film 24, and the generated electrons pass through the electrode connection terminal 35 connected to the oxygen electrode 23 and the power supply unit 3 to the hydrogen electrode 22. Moving. That is, water (H ₂ O) is electrolyzed by a reaction of 2H ₂ O → 4H ⁺ + O ₂ + 4e ⁻ . Note that the generated oxygen is discharged from the oxygen discharge connection portion 33 to the outside, for example.

A PEM (Proton Exchange Membrane) film 24 is provided with a structure sandwiched between a hydrogen electrode 22 and an oxygen electrode 23. The PEM film 24 is an electrolytic film capable of transmitting hydrogen ions (H ⁺ ) generated by electrolyzing water from the oxygen electrode 23 side to the hydrogen electrode 22 side.

The hydrogen electrode 22 is a cathode made of an electrode material for water electrolysis having a hydrogen electrode catalyst layer not containing a platinum group element. On the hydrogen electrode 22 side, hydrogen (H ₂ ) is discharged through, for example, a hydrogen discharge connection portion 31 connected to an external hydrogen supply destination and a hydrogen storage portion 25 that discharges hydrogen to the hydrogen supply destination.

In the hydrogen electrode 22, the generated hydrogen ions (H ⁺ ) and electrons (e ⁻ ) react with 2H ⁺ + 2e ⁻ → H ₂ to generate hydrogen. At this time, hydrogen ions generated on the oxygen electrode 23 side pass through the inside of the PEM film 24, and electrons moving from the oxygen electrode 23 are connected to the electrode connection terminal 35 and the power supply unit 3 connected to the hydrogen electrode 22. And move to the hydrogen electrode 22.

  Next, FIG. 3 shows an example of the structure of the electrode part 2B (another embodiment of the electrode part 2) used in the hydrogen generator 1 of FIG. FIG. 4 shows an example of the structure of the hydrogen electrode unit 22b used in the electrode part 2B of FIG.

  As shown in FIG. 4, the hydrogen electrode unit 22 b includes a water electrolysis electrode material (hydrogen electrode 22) and a sealing plate 222. Also, the oxygen electrode unit 23b shown in FIG. 3 has the same structure as that of the hydrogen electrode unit 22b shown in FIG. 4 and is composed of a water electrolysis electrode material (oxygen electrode 23) and a sealing plate 232.

  As shown in FIG. 4, the sealing plate 222 is disposed adjacent to each other so that the flat surfaces of the hydrogen electrode 22 and the flat plate face each other, and the sealing plate 232 is adjacent so that the flat surfaces of the oxygen electrode 23 and the flat plate face each other. Arranged. Further, since gas is generated from the hydrogen electrode 22 and the oxygen electrode 23, the sealing plates 222 and 232 are fixed so as to sandwich the hydrogen electrode 22 and the oxygen electrode 23 from the outside in the sealed container shown in FIG. The sealing plates 222 and 232 are made of a known metal material such as a stainless sintered body.

  The sealing plate 222 is provided with a plurality of fine holes 223 dispersed on the flat plate so that the generated gas or water can pass therethrough. The fine hole 223 is provided so as to penetrate from the surface of one end of the flat plate of the sealing plate 222 to the surface of the other end. The hydrogen gas generated at the hydrogen electrode 22 passes through the plurality of fine holes 223 of the sealing plate 222 and can be discharged to the hydrogen storage unit 25. The sealing plate 232 has the same configuration.

  For example, in the hydrogen generator 1 shown in FIG. 1, the hydrogen discharge connection part 31 is connected to the gas-liquid separator 12 outside the sealed container of the electrode part 2B (2). Thereby, the hydrogen produced | generated by the hydrogen electrode 22 can be sent to the gas-liquid separator 12 from an airtight container.

  As described above, according to the hydrogen generator 1 of the present embodiment, by supplying hydrogen gas as fine bubbles to the hot water supply piping route for supplying water and hot water, Since fine bubbles can enter the uneven portions of the dirt component, there is a sterilizing / cleaning effect in these pipes.

  In addition, since the bubbles are homogeneous and fine, when supplied to the hot water supply piping route for water and hot water supply, the water flow is not a turbulent flow, but a laminar flow through the flow path. Water and hot water containing gas bubbles can be supplied. Thereby, the skin beautifying effect and the cleaning effect can be expected.

<Example of production of molded article>
Next, the electrode material for water electrolysis (hydrogen electrode 22 and oxygen electrode 23) will be described. FIG. 5 shows an example of the structure of the hydrogen electrode 22 and the oxygen electrode 23.

  Conventionally, research and development related to transition metals and noble metals have been conducted on the catalytic action of electrode materials for water electrolysis. In particular, in the present invention, a water electrolysis electrode material having a highly active catalytic action can be provided by using different transition metals other than platinum group elements or a combination thereof with other metals.

  The electrode material for water electrolysis is made of a metal material that does not contain a platinum group element (Ru, Rh, Pd, Os, Ir, Pt). The electrode material for water electrolysis is a molded body mainly composed of Fe or Ni, and includes a molded body containing at least a plurality of different transition metals belonging to Fe or Ni and a 3d transition metal as a metal material. This molded body is made of a mixture containing powders of each of these metal materials, and voids dispersed in the molded body so that water, hydrogen gas, and oxygen gas used for the electrode part 2 can permeate the molded body. Each of the powders is formed by mixing so as to have.

  Preferably, the plurality of different transition metals include at least one of Fe, Ni, Mn, Cr, or Ti belonging to the 3d transition element. Further, the molded body contains any one of Cu, Zn, Al, or Mg, which is higher in electrical conductivity than the transition metal contained, as a metal material other than the contained transition metal.

  Therefore, as an example, an example of a material (a material used as a hydrogen electrode catalyst layer or an oxygen electrode catalyst layer) that exhibits a highly active catalytic action with a different transition metal other than the platinum group element or a combination of these and other metals. Show and explain. For example, examples are shown in which several different molded bodies are manufactured under the manufacturing conditions described below. The appearance of the hydrogen electrode 22 and the oxygen electrode 23 shown in FIG. 5 is a prototype water electrode material for water electrolysis (prototype molded body).

<Electrode material for water electrolysis>
In the examples of the electrode material for water electrolysis (hydrogen electrode 22 and oxygen electrode 23) of the present embodiment, for example, a molded body containing a plurality of different transition metals as described below is used.

  In terms of material cost, it is preferable to include Fe and Ni, Fe and Cu, or Ni and Cu as a plurality of different transition metals. For example, the embodiment shown in FIG. 5 contains a large amount of Fe as a 3d transition metal among different transition metals, and a small amount of Cu in a mass ratio compared to Fe and about the same amount as Fe as other 3d transition metals. A molded body containing a small amount of Ni. That is, more preferably, from the viewpoint of material cost, it is a molded body mainly composed of Fe among 3d transition metals.

  These transition metals or powders of these and other metals are mixed so as to be uniform throughout. Then, the mixed powder is pressed and sintered to form a molded body. The molded body produced in this way has a large number of holes on the surface of the molded body so that hydrogen gas, oxygen gas, water, solution, etc. can permeate the thickness direction of the molded body, and molding is performed. It has a structure in which many voids are provided inside the body (also referred to as a multiporous structure).

  For example, when powder is filled in a mold having a certain shape and pressure is applied, the gap between the powders decreases as the pressure increases. Thus, the porosity of a molded object can be adjusted with the magnitude | size of a pressure. For this reason, in order to manufacture a molded object so that it may exist in the range of the desired porosity, the pressure to pressurize is controlled.

  Note that the porosity changes slightly depending on the sintering temperature and time during sintering after pressurization, so that the molded product that is finally produced can be obtained by adjusting and controlling these conditions as well. Manufactured to be in the range of porosity.

  The space provided in the molded body is a space surrounded by the surfaces of a plurality of different transition metals or other metals. In addition, on the surface, a plurality of holes that continue to the voids of the molded body are formed. As the plurality of transition metals contained in the molded body, 3d transition metals are preferable.

  For example, in the molded body of the example shown in FIG. 5, a plurality of different 3d transition metals contain, for example, mainly Ni and a small amount of Cu and Fe. Specifically, the molded body shown in FIG. 5 is provided with voids surrounded by metal in a proportion corresponding to the number of particles having a mass ratio of Fe: Ni: Cu = 1: 48: 4. For example, in a molded body expressed as Fe-48Ni-4Cu, the composition ratio of Fe, Ni, and Cu is 1: 48: 4 in terms of mass ratio.

  Further, for example, a plurality of different 3d transition metals contain, for example, Fe as a main component, Ni in the same amount or a small amount, and Cu or the like in a small amount. Specifically, the molded body shown in FIG. 5 is provided with voids surrounded by metal in a proportion corresponding to the number of particles having a mass ratio of Fe: Ni: Cu = 48: 48: 4. For example, in a molded body represented as 48Fe-48Ni-4Cu, the composition ratio of Fe, Ni, and Cu is 48: 48: 4 in terms of mass ratio.

The effect of the space | gap provided in the above molded objects is demonstrated. For example, in the electrode material for water electrolysis used in the hydrogen electrode unit 22b and the oxygen electrode unit 23b shown in FIG. 3, hydrogen ions that permeate through the voids surrounded by the powder as described above pass through these voids. In this case, it has a catalytic action that promotes the reaction on the right side of (Formula 1) and (Formula 2).
(Oxygen electrode) H ₂ O → 1/2 · O ₂ + 2H ⁺ + 2e ⁻ (Expression 1)

  That is, a catalytic action that promotes a reaction for electrolyzing water is exerted on the surface of the void in the electrode material for water electrolysis (oxygen electrode 23) and the surface near the boundary with the PEM film 24. Conventionally, as the electrode material for water electrolysis, a material in which a platinum catalyst is supported on a carbon black carrier has been used. Instead, the electrode material for water electrolysis can be used.

The hydrogen ions (H ⁺ ) generated by (Equation 1) pass through the PEM film 24 that is an electrolytic film and reach the hydrogen electrode 22.
(Hydrogen electrode) 2H ⁺ + 2e ⁻ → H ₂ (Formula 2)

Here, on the surface of the void in the electrode material for water electrolysis (hydrogen electrode 22), a catalytic action that promotes a reaction in which hydrogen ions (H ⁺ ) and electrons (e ⁻ ) are combined to form hydrogen is exerted. .

That is, the hydrogen ion (H ⁺ ) that has reached the hydrogen electrode 22 of the hydrogen electrode unit 22b is connected to the power supply unit 3 or the like in the vicinity of the boundary where the PEM film 24 and the electrode material for water electrolysis are in contact with each other. As shown in (Formula 2), hydrogen is generated by the reaction with the electrons (e ⁻ ) supplied from the base.

<Example of production of molded article>
For example, an example in which several different molded bodies are manufactured under the manufacturing conditions described below will be shown. FIG. 5 described above shows the appearance of the prototype. FIG. 6 is a list showing an outline of the prototypes (water electrolysis electrode materials (hydrogen electrode 22 and oxygen electrode 23)).

  The compact shown in FIG. 5 is a hydrogen electrode 22 and an oxygen electrode 23 for use in the electrode portions 2A and 2B. In the hydrogen electrode 22 and the oxygen electrode 23 shown in FIG. 5, a large number of holes are formed in a disk-shaped surface. Many of the holes are formed by connecting many of the voids inside the molded body. The voids inside the molded body are formed so that water, hydrogen, oxygen, and hydrogen ions used for the electrode portions 2A and 2B and the like can pass through the molded body. For example, when a water droplet is dropped on the hydrogen electrode 22 and the oxygen electrode 23 shown in FIG. 5 and the surface is rubbed by hand with the surface immersed in the water droplet, the water droplet is absorbed into the molded body.

  As an example of this embodiment, for use as the hydrogen electrode 22 and the oxygen electrode 23 of the electrode portions 2A and 2B, the prototypes No11, No12, No13, and No14 shown in FIG. 6 (electrode materials for water electrolysis) are prototyped. did. As production conditions for the prototypes No. 11 to No. 14, the respective materials, sintering temperature, sintering time, pressure during sintering, and other conditions are as shown below.

<Material of molded body>
The metal materials of trial production No11 and No12 are 48Fe-48Ni-4Cu. That is, the metal material contains Fe (iron), Ni (nickel), and Cu (copper) metals in a mass ratio of about 48: 48: 4. Moreover, the metal material of trial manufacture No13 and No14 is Fe-48Ni-4Cu. That is, the metal material contains Fe (iron), Ni (nickel), and Cu (copper) metals in a mass ratio of approximately 1: 48: 4.

<Powder shape>
Preferably, the powder to be mixed for manufacturing the molded body is spherical or acicular, or at least one type of metal material is processed into a spherical shape and another type of metal material is processed into an acicular shape.
Further, preferably, among the metals contained in the compact, at least the metal having the lowest melting point is spherical, and the other metal having the highest melting point is a needle-like powder.

  When needle-shaped powder is used, when the mixed powder is pressure-molded, it is easy to form a void having good permeability in the finished molded body. Further, if the metal having the lowest melting point is a spherical powder, the surface area when joining to another metal can be increased.

  Each transition metal or metal, or an alloy containing the transition metal or the like is pulverized by a pulverizer so as to be equal to or smaller than a predetermined average particle diameter to obtain powder. The average particle diameter of the powder (for example, the length of the longitudinal portion of the longitudinal shape or the outer diameter of the sphere) is 200 (μm) or less. For example, the pulverized powder is passed through a mesh that allows a pore diameter of about 200 (μm) or less to pass through, for example, in a processing step, and sieved. This is because if the average particle diameter exceeds 200 (μm), it becomes difficult to maintain the strength due to warpage or cracks of the molded article to be produced.

  Preferably, the average particle size is 10 to 200 (μm). If the average particle diameter of many powders is less than 10 (μm), voids (pores) are likely to close during pressing and sintering, and the manufactured molded product has a transmittance of oxygen, hydrogen, etc. It is because it falls. In some cases, the average particle diameter may be less than 10 (μm) in a small part of the powder by treatment with a pulverizer or the like, but there is no practical problem when a very small amount is contained.

<Pressing pressure>
Each transition metal or metal powder is mixed so as to be uniformly dispersed by a mixer or the like, and the mixed powder is put into a mold for molding and pressed at a predetermined pressure. The pressure at the time of pressurization is about 5 to 8 (t / cm ² ), in other words, about 500 to 800 (Mpa).

  As a guideline, if the pressure during pressurization is less than 500 (Mpa), the voids are slightly too large (the porosity is too high), and cracks and warpage tend to enter the produced molded body. The strength of is reduced. Moreover, it is because the space | gap of the manufactured molded object will become a little too small (the porosity will become low too much) when the pressure at the time of pressurization exceeds 800 (Mpa).

  On the other hand, the voids (also referred to as pores) provided in the molded body are within the above-mentioned range because they affect the transmittance of the hydrogen electrode 22 through which hydrogen permeates and the oxygen electrode 23 through which oxygen permeates. A higher rate is preferred.

<Sintering conditions>
Next, after the mixed powder is put into a mold and subjected to pressure molding, the compact is sintered. For example, a compact (Fe-48Ni-4Cu) containing a metal whose composition ratio of Fe (iron), Ni (nickel), and Cu (copper) is approximately 1: 48: 4 by mass ratio, and approximately 48 by mass ratio. The sintering conditions for sintering the compact (48Fe-48Ni-4Cu) containing a metal of 48: 4 are as follows.

(1) Sintering temperature 1100-1400 ° C
As a guideline, when the sintering temperature is below 1100 ° C., the melting point of Cu contained in the molded body is 1084 ° C., particularly on the inner side of the molded body. In this case, since Cu having high electrical conductivity does not melt, it is difficult to closely bond to other transition metal powders. On the other hand, when the sintering temperature exceeds 1400 ° C., especially when the melting point of Ni contained in the compact is higher than 1455 ° C., a certain amount of voids are provided in the pressure-molded state. Since melting of Ni starts by heating, the formed voids are extremely deformed, and problems such as blocking pores occur. Moreover, it becomes difficult to adjust a desired porosity.

(2) Sintering time About 4-6 hours At the set sintering temperature, a sufficient heating time is provided, and the compact is sintered at about normal pressure (atmospheric pressure). The sintering time of 4 to 6 hours is data based on experience. Further, an inert gas is used in the atmosphere so that the metal is not oxidized during sintering.

  (3) After sintering, natural cooling is performed. Moreover, although it may cool by a cooling fan or water cooling, it is not necessary to cool rapidly in time. This is because, when rapidly cooled, the molded body is likely to be cracked, warped, or the like.

<Manufacturing method>
Hereinafter, an example of the manufacturing method of the electrode material for water electrolysis of this embodiment is demonstrated.
As a basic process, a plurality of different transition metals other than platinum group elements or powders of these and other metals are mixed so as to be uniform overall, and the mixed powder is pressed and sintered, It is a manufacturing method including the process of manufacturing a molded object (electrode material for water electrolysis). For example, the manufacturing method of the electrode material for water electrolysis includes the following steps.

(Crushing process)
First, a 1st process is a grinding | pulverization process grind | pulverized to 200 micrometers or less as a powder for every transition metal or those and another metal.
Preferably, the pulverizing step further includes a shape processing step in which the powder is processed into a spherical shape or a needle shape, or at least one type of metal material is processed into a spherical shape and another type of metal material is processed into a needle shape.

(Mixing process)
Next, the second step is a mixing step in which powders containing different transition metals are mixed so as to be uniformly dispersed after the pulverization step.

(Pressure process)
Next, the third step is a pressurization step in which the uniformly dispersed powder is put into a mold after the mixing step and is pressed at a pressure of about 500 to 800 MPa to form a molded body.
(Sintering process)
Next, a 4th process is a sintering process which sinters a molded object at high temperature after a pressurization process. Preferably, the sintering time is about 4 to 6 hours at the sintering temperature set in the sintering step.

  Preferably, in the sintering step, the sintering temperature is in a range higher than the melting point of the metal having the highest electrical conductivity among the metal materials and lower than the melting point of the metal other than the metal having the highest electrical conductivity. .

  The reason for the above sintering temperature is that when heating is started in the sintering process, the powders are joined by surface diffusion, and the heating temperature is the melting point of the metal having the highest electrical conductivity among the included metals. As a result, the internal diffusion also occurs inside the powder of the molded body, and the powders are bonded to each other. As a result, a metal having high electrical conductivity is closely bonded to other powders in the sintered compact.

  For example, 48Fe-48Ni-4Cu or Fe-48Ni-4Cu molded body metal material includes Fe and Ni belonging to the 3d transition element, and further includes the 3d transition metal Fe, Ni contained as the metal material. A case of an example including Cu having a higher electric conductivity will be described. Cu is also a 3d transition metal.

For example, at an atmospheric pressure of 1 atm, the melting point of Cu is 1084 ° C., the melting point of Fe is 1536 ° C., and the melting point of Ni is 1455 ° C. (see Science Chronology, Vol. 88, 2015). Further, where the term high electric conductivity and is, for example, when compared with the value of the electrical resistivity (and 0 ℃ ^{reference), Fe: 8.9 (10 -8} Ωm), Ni: 6.2 (10 - Compared with 3d transition metals such as ⁸ Ωm), Al: 2.50 (10 ⁻⁸ Ωm), Cu: 1.55 (10 ⁻⁸ Ωm), Mg: 3.94 (10 ⁻⁸ Ωm), etc. It is a metal having electrical resistance characteristics (see Science Chronology, Vol.88, 2015).

  In this case, in the sintering process of the compact including the powders of Fe, Ni, and Cu (when the pressure is 1 atm), the sintering temperature is the melting point of the metal Cu having the highest electrical conductivity among the metal materials. The range is higher than 1084 ° C. and lower than the melting point of the metal other than the metal having the highest electrical conductivity (Ni melting point: 1455 ° C.). That is, the sintering temperature is in the range of 1100 to 1400 ° C., for example.

  As an example of this embodiment, as shown in FIG. 6, prototypes No. 11, No. 12, No. 13 and No. 14 used for the hydrogen electrode 22 and the oxygen electrode 23 were prototyped by the manufacturing method as described above. FIG. 6 is a list showing an outline of these prototypes. In particular, it shows characteristics such as the external shape and density of the prototype.

  FIG. 6 shows the electrode material, the substantially disk-shaped average outer shape, the average thickness, the density, the relative density, and the sintering temperature for each prototype No. (prototype type) of the molded body used as the hydrogen electrode 22 and the oxygen electrode 23. . In addition, as manufacturing conditions of trial manufacture No11-No14, each sintering temperature, sintering time, sintering conditions, such as the pressure at the time of sintering, and other conditions are as having mentioned above, Here, it is mainly trial manufacture No11. , No12, No13, No14 will be described with respect to the differences in the trial production conditions.

<Material of molded body>
The metal materials of prototype No11 and No12 are 48Fe-48Ni-4Cu, and the metal material of prototype No13 and No14 is Fe-48Ni-4Cu. Here, the notation of 48Fe-48Ni-4Cu indicates that the composition ratio of Fe (iron), Ni (nickel), Cu (copper) contained as a metal material is 48: 48: 4 by mass ratio, and Fe-48Ni The notation of -4Cu indicates that the composition ratio of Fe (iron), Ni (nickel), and Cu (copper) contained as a metal material is 1: 48: 4 in mass ratio. In this material, each metal is easily available, and the material cost is low.

<Density of molded body>
After the sintering, as shown in FIG. 6, the average outer shape and the average thickness of the molded body were measured for each of the prototype Nos. 11 to 14. Further, the volume of the molded body was calculated from the average outer shape and the average thickness, and the mass for each prototype No. was measured, and the measured mass was divided by the calculated volume to calculate each density.

<Relative density of molded body>
The relative density of the molded body shown in FIG. 6 is calculated as follows.
In the known technology, if the particle diameter of the close-packed particles is combined (the smaller particles are filled in the gaps between the particles and the particles are mixed and adjusted), the theoretical porosity can be filled to about 4%. Are known. Therefore, the relative density of the molded body is calculated by setting such a metal plate that is closest packed (filled with 96% of particles) to 100% relative density.

For example, the density at a relative density of 100% of Fe-48Ni-4Cu and 48Fe-48Ni-4Cu used as a reference is calculated using the following data (see Science Chronology, Vol. 88, 2015) did.
Fe density: 7.874 (g / cm ³ ), 20 ° C.
Ni density: 8.902 (g / cm ³ ), 25 ° C.
Cu density: 8.96 (g / cm ³ ), 20 ° C.
Here, when the composition ratio of Fe, Ni, and Cu is 1: 48: 4 by mass ratio, for example, when the mass and volume of the metal are simply added at these ratios, the volume per 53 (g) is 5. Since 9654 (cm ³ ), 53 (g) /5.9654 (cm ³ ) = 8.885 (g / cm ³ ).

When the composition ratio of Fe, Ni, and Cu is 48: 48: 4 by mass ratio, for example, when the mass and volume of the metal are simply added at these ratios, the volume per 100 (g) is 11.934. Since it is (cm ³ ), 100 (g) /11.934 (cm ³ ) = 8.379 (g / cm ³ ).

Therefore, when it is a metal plate that is closest packed with Fe, Ni, Cu powder as particles,
For the density ρ1 of 48Fe-48Ni-4Cu,
ρ1 = 8.379 (g / cm ³ ) × 0.96 = 8.04 (g / cm ³ )
・ In density ρ2 of Fe-48Ni-4Cu,
ρ2 = 8.885 (g / cm ³ ) × 0.96 = 8.53 (g / cm ³ )
Calculate as The relative density shown in FIG. 6 was calculated using the above density ρ1 = 8.04 (g / cm ³ ) and ρ2 = 8.53 (g / cm ³ ) as a comparison standard with a relative density of 100%.

From the above, as shown in FIG. 6, the relative density of each of the prototypes No. 11 to No. 14 is substantially based on the density ρ1 = 8.04 or ρ2 = 8.53 (g / cm ³ ), where the relative density is 100%. It was calculated as 69%, 79%, 75%, and 82%.

<Calculate the porosity of the molded body>
The metal plate used as the closest packing described above is defined as 100% relative density, and the relative porosity at this time is defined as 0%, and the porosity of the molded body is defined as (Equation 3). To do.
Porosity = 100−relative density (%) (Formula 3)

Based on the result of the relative density shown in FIG. 6, when calculating the porosity according to (Equation 3) for the prototype No. 11 to No. 14,
(Prototype No11) relative density 69%, porosity 31%
(Prototype No. 12) Relative density 79%, porosity 21%
(Prototype No. 13) Relative density 75%, porosity 25%
(Prototype No. 14) relative density 82%, porosity 18%
The result is as described above. In addition to this, regarding the calculation of the porosity, there may be a method of calculating by measuring the amount of water or oil (liquid with a small contact angle) impregnated into the molded body.

<Differences in sintering temperature under prototype conditions>
・ Sintering temperature Temperature Hi = 1100 to 1300 ° C. (center temperature around 1200 ° C.)
Temperature Lo = 1000 to 1200 ° C. (center temperature about 1100 ° C.)

  In the material 48Fe-48Ni-4Cu, the sintering temperature of the trial production No11 is the above temperature Hi, and is in the range of the center temperature 1200 ° C. sufficiently higher than the melting point 1084 ° C. of Cu. On the other hand, the sintering temperature of the trial No. 12 is the temperature Lo, which is about 1100 ° C. at the center temperature close to the melting point of Cu of 1084 ° C. In addition, in the material Fe-48Ni-4Cu, the sintering temperatures of the prototypes No. 13 and No. 14 are the temperature Lo.

  Therefore, in the range of 1200 ° C., which is sufficiently higher than the melting point of 1084 ° C., the Cu solid powder transitions to the liquid state. That is, in the sintering process, which is the sintering temperature of the prototype No11, Cu has a lower melting point than other transition metals and has a high conductivity (high electrical conductivity) if the sintering temperature is 1100 to 1300 ° C. Melts and is in a state of being closely bonded to Ni and Fe powder having a high melting point (melting point higher than that of one metal).

  On the other hand, since the center temperature of the prototype Nos. 12, 13, and 14 is 1100 ° C., in particular, many portions on the inner side of the molded body have 1000 to 1084 sintering temperatures lower than the melting point of Cu of 1084 ° C. It is considered to be in the range of ° C., and in the sintering process, since it remains a Cu solid powder at the time of pressure forming, it is not in a state where it is sufficiently bonded to Ni and Fe powder. Conceivable.

  Referring to FIG. 6, the sintering temperature in trial production No11 is a molded body sintered at a temperature Hi higher than the temperature Lo. As described above, at a high temperature Hi (sintering temperature 1100 to 1300 ° C .: center temperature around 1200 ° C.), Cu powder having a high electric conductivity melts and has a high melting point (a melting point higher than that of one transition metal). ) And Ni and Fe powders.

  On the other hand, at temperature Lo (sintering temperature 1000 to 1200 ° C .: center temperature about 1100 ° C.), the sintering temperature is lower than the melting point 1084 ° C. of Cu, particularly on the inner side of the molded body. In this case, since Cu does not melt, it is difficult to closely bond to other transition metal powders. According to the water electrolysis experiment, hydrogen gas generation could be confirmed in any of the prototype No. 11 to No. 14, but when the prototype No. 11 and the prototype No. 12 to No. 14 were compared, The electrode material was presumed to have a better electrolysis efficiency of water, but in this experiment, a large difference in the amount of hydrogen gas generated could not be observed.

  Although the number of samples in FIG. 6 is not large, the porosity of the molded body and the efficiency of water electrolysis in the electrode material for water electrolysis are within a certain range of porosity (20 to 40%). However, the hydrogen generation efficiency in water electrolysis tends to be improved.

  Preferably, the porosity of the molded body is in the range of 20 to 40% with respect to the volume of the molded body (or with respect to 100% relative density of the metal plate that is the closest packed). This is because when the porosity is less than 20%, the transmittance of products such as hydrogen gas and oxygen gas is decreased, and the surface area ratio of the void is also decreased. On the other hand, if the porosity exceeds 40%, the strength of the molded body becomes weak in the structural aspect of the molded body, and it is difficult to maintain sufficient strength.

  With respect to the prototype material shown in FIG. 6, as an electrode material for water electrolysis (anode catalyst) containing a transition metal other than a platinum group element, a catalytic action that promotes a reaction to release electrons and become hydrogen ions was confirmed. Moreover, the catalytic action which produces | generates hydrogen gas was able to be confirmed as an electrode material for water electrolysis (cathode catalyst) containing transition metals other than a platinum group element.

In addition to the above examples, as the metal material in the molded body, when the mass of the molded body is 100 mass%, Mg is 1 to 3 mass%, Zn is 2 to 3 mass%, or Al is 5 to 5 mass%. It is preferable to include at least 6% by mass, including Ni, Fe, and Cr, with a total of mass% obtained by subtracting mass% of the contained metal from 100% by mass.
Other Examples 1) Ni, Fe, Cr, Mg: Other Examples including 1 to 3% by mass of Mg 2) Ni, Fe, Cr, Zn: Other Examples including 2 to 3% by mass of Zn 3) Ni, Fe, Cr, Al: It has been found that a combination of a 3d transition metal containing 5 to 6 mass% of Al and the above metal is also promising as an electrode material for water electrolysis.

  Further, as the metal material used for the powder, not only a single metal but also an alloy of two or more metals, for example, an alloy of Ni and Fe, may be used as a powder. Moreover, you may use the powder below a predetermined particle diameter.

  Since a material that does not use a platinum group element is used for the electrode material for water electrolysis, the manufacturing cost of the hydrogen generator can be reduced. In addition, since a metal that is not a scarce resource can be used, the problem of resource problems can be solved.

  As described above, the present invention relates to a water electrolysis electrode material having a catalytic action without using a platinum group element. In addition, as an example of the present embodiment, a water electrolysis electrode material having a catalytic action, a method for producing the same, and a hydrogen generator can be provided without using a platinum group element.

[Third Embodiment]
Still another configuration example of the electrode unit 2 is shown as the hydrogen generator 1 of the third embodiment. Here, FIG. 7 shows an example of another structure (electrode part 2C) of the electrode part 2 used in the hydrogen generator 1 of FIG.

  The electrode part 2C shown in FIG. 7 is a structure in the case of using the hydrogen electrode unit 22c and the oxygen electrode unit 23c. The electrode portion 2C shown in FIG. 7 is oxidized as a second hydrogen electrode catalyst layer 220 and a second oxygen electrode catalyst layer 230 with respect to the electrode material for water electrolysis as compared with the electrode portion 2B shown in FIG. The difference is that a titanium electrode is used and an ultraviolet irradiation means 28 for irradiation with ultraviolet rays is provided.

  As shown in FIG. 7, the electrode portion 2C is a sealed container including a hydrogen electrode unit 22c, an oxygen electrode unit 23c, and a PEM film 24 in the container. The sealed container is provided with a hydrogen storage unit 25, a water storage unit 26, a hydrogen discharge connection unit 31, an oxygen discharge connection unit 33, a water discharge unit 32, and a water supply connection unit 34. That is, the structure is such that water can be supplied and water, hydrogen gas, and oxygen gas can be discharged from inside and outside the container.

  The electrode portion 2C is formed of a sealed container capable of taking out the generated hydrogen, and the hydrogen electrode unit 22c and the oxygen electrode unit 23c are provided so as to sandwich both sides of the PEM film 24 in the sealed container. In the example of FIG. 7, the hydrogen electrode 22 and the oxygen electrode 23 are provided so as to directly sandwich the PEM film 24 from both sides.

  Further, the hydrogen electrode unit 22 c includes a hydrogen electrode 22 and a second hydrogen electrode catalyst layer 220. The second hydrogen electrode catalyst layer 220 is closely stacked so as to cover the flat plate side of the hydrogen electrode 22 from the space side of the hydrogen storage portion 25.

  The oxygen electrode unit 23 c includes the oxygen electrode 23 and the second oxygen electrode catalyst layer 230. The second oxygen electrode catalyst layer 230 is closely stacked so as to cover the plane plate side of the oxygen electrode 23 from the space side of the water storage portion 26.

  The ultraviolet irradiation means 28 is disposed in the sealed container of the electrode part 2C so that the flat surface of the second hydrogen electrode catalyst layer 220 can be irradiated into the space of the hydrogen storage part 25. Similarly, the ultraviolet irradiation means 28 is arranged so that the flat surface of the second oxygen electrode catalyst layer 230 can be irradiated into the space of the water storage unit 26. The ultraviolet irradiation means 28 is connected to an irradiation power source 30 provided in the power supply unit 3, and irradiation power is supplied from the irradiation power source 30.

  The ultraviolet irradiation means 28 includes, for example, a light emitting source that emits ultraviolet light, an ultraviolet light guide provided in the vicinity of the electrodes of the second hydrogen electrode catalyst layer 220 and the second oxygen electrode catalyst layer 230, and ultraviolet light emitted from the light source. Is composed of a light guide wire or the like for guiding the light to the ultraviolet light guide. As the light source, UV-LED (ultraviolet LED) can be preferably used. As the ultraviolet light guide path, for example, a resin-made or glass-made rod-like body or tube capable of transmitting ultraviolet rays can be used.

The titanium oxide electrode used for the second hydrogen electrode catalyst layer 220 and the second oxygen electrode catalyst layer 230 is, for example, Ti (titanium), TiO ₂ (titanium oxide), Ni (nickel), Fe (iron), Cr ( Chromium), Pt (platinum), Co (cobalt), and Rh (rhodium) powders can be used for powder metallurgy, and Ti and TiO ₂ are placed around an electrode core formed of a stainless steel rod. It can also be formed by powder metallurgy. As for the mass ratio of each metal after sintering performed by powder metallurgy, the ratio of TiO ₂ is preferably 3 to 5 mass% of the whole. Thus, the effect based on various TiO ₂ to be described later is sufficiently exhibited. In addition, it is more preferable to include platinum group elements such as Pt and Rh, and Co since decomposition of water can be promoted.

Further, when viewed in Ti and portions the ratio of TiO ₂ was formed by powder metallurgy, Ti concentration 5-7% by weight, it is preferably contained as TiO ₂ concentration of 3 to 5 wt%. Thus, by forming the surfaces of the second hydrogen electrode catalyst layer 220 and the second oxygen electrode catalyst layer 230, which are titanium oxide electrodes, with a porous sintered metal layer, the surface area of the electrode can be increased, and the water to be electrolyzed. The contact area with can be increased. In addition, the amount of titanium oxide present on the electrode surface can be increased. Thereby, the electrolysis efficiency of water and the photolysis efficiency of water can be improved.

Moreover, in the aspect of the electrode part 2C provided with the ultraviolet irradiation means 28 for irradiating the second hydrogen electrode catalyst layer 220 and the second oxygen electrode catalyst layer 230, the second hydrogen electrode catalyst layer 220 has SrTiO ₃ (titanic acid). Strontium) is preferably included, and WO ₃ (tungsten oxide) is preferably included in the second oxygen electrode catalyst layer 230.

  Hydrogen generation from the second hydrogen electrode catalyst layer 220 is performed by including strontium titanate in the second hydrogen electrode catalyst layer 220 for generating hydrogen and irradiating ultraviolet rays of 400 to 800 nm by the ultraviolet irradiation means 28, for example. Can be promoted. Further, tungsten oxide is included in the second oxygen electrode catalyst layer 230 that generates oxygen, and ultraviolet rays are irradiated by the ultraviolet irradiation means 28. Thereby, oxygen generation from the second oxygen electrode catalyst layer 230 can be promoted.

  Also in this case, by forming the surface of the titanium oxide electrode with a porous sintered metal layer, the surface area of the electrode can be increased, and the amount of strontium titanate and tungsten oxide present on the electrode surface can be increased. In addition, when it is preferable that the amount of oxygen generated in the electrode portion 2C is small, it is not necessary to include tungsten oxide in the second oxygen electrode catalyst layer 230.

Next, a process of generating hydrogen from water will be described for the case where the electrode unit 2C is used in the hydrogen generator 1 of the third embodiment.
When a power switch (not shown) of the hydrogen generator 1 (corresponding to FIG. 1) is pressed to turn on the power, a voltage is applied from the power supply unit 3 to the hydrogen electrode unit 22c and the oxygen electrode unit 23c, and FIG. Irradiation power is supplied from the irradiation power supply 30 to the ultraviolet irradiation means 28 shown. Thereby, the ultraviolet irradiation means 28 irradiates the second hydrogen electrode catalyst layer 220 and the second oxygen electrode catalyst layer 230 with ultraviolet rays.

  7, oxygen is generated from the anode oxygen electrode unit 23c and hydrogen is generated from the cathode hydrogen electrode unit 22c by electrolysis of water. Further, by irradiating the second hydrogen electrode catalyst layer 220 and the second oxygen electrode catalyst layer 230 with ultraviolet rays, oxygen and hydrogen are generated by photolysis of water (Honda-Fujishima effect) and negative ions are generated. To do.

  As described above, in the hydrogen generator 1 of this embodiment, by irradiating the titanium oxide electrode with ultraviolet rays, oxygen and hydrogen can be generated by photolysis of water in addition to electrolysis of water. Moreover, since the hydrophilicity of the electrode surface is increased by irradiating the titanium oxide electrode with ultraviolet rays, the generated hydrogen and oxygen are easily separated from the electrode.

  In addition, when the titanium oxide electrode is irradiated with ultraviolet rays, the electrode is self-cleaning due to the increase in hydrophilicity of the electrode surface and the decomposition effect of the organic matter, so that the contamination of the electrode can be prevented.

  With these features, the hydrogen generation apparatus 1 of the present embodiment can increase the hydrogen generation efficiency as compared with the case of only electrolysis. Therefore, since hydrogen can be generated with high generation efficiency, the apparatus can be made compact.

In the electrode portion 2C, the titanium oxide electrodes used for the second hydrogen electrode catalyst layer 220 and the second oxygen electrode catalyst layer 230 are Ti (titanium), TiO ₂ (titanium oxide), Ni (nickel), Fe ( It is formed by powder metallurgy using powders of iron, Cr (chromium), Pt (platinum), Co (cobalt), and Rh (rhodium), and the ratio of TiO ₂ after sintering is 3 to 5% by mass of the whole. Preferably there is. Thereby, hydrogen can be generated with higher generation efficiency.

  As described above, according to the hydrogen generator 1 of this embodiment, the hydrophilicity of hydrogen gas is improved in addition to the effects of the second embodiment. If the hydrophilicity is good, hydrogen gas is likely to diffuse well into hot water. For example, there are effects such that bubbles do not concentrate at the drain of the bath and hydrogen gas is more easily diffused.

  As a result, by supplying highly hydrophilic hydrogen gas to the hot water supply piping route for water and hot water supply, sterilization of hot water supply piping such as water supply and hot water supply pipes, precipitates and other deposits on the surface of the bathtub・ Excellent cleaning effect. In addition, a skin-beautifying effect can be expected by using water or hot water containing hydrogen gas having good hydrophilicity.

    [Fourth Embodiment]

  FIG. 8 shows an embodiment of a hot water supply system. The hot water supply system shown in FIG. 8 mainly includes a hot water supply facility 10 having the hydrogen generator 1 and the hot water supply device 7 of any of the embodiments described above. Moreover, the hot water supply facility 10 is connected to the bathtub facility 8 through a piping facility such as a hot water supply piping so that water and hot water can be supplied.

  In the hot water supply system of the present embodiment, an example of the bathtub equipment 8 will be described as an example of equipment to which the hot water supply system is applied. However, in the hot water supply equipment 10, water can be supplied to a sink, kitchen equipment, etc. via a hot water supply pipe equipment. It may be connected like this. Hereinafter, the configuration of the hot water supply system will be described with reference to FIG.

  The hydrogen discharge on / off valve 15 is a valve that is provided on the piping path of the hydrogen discharge pipe and that can be opened and closed for supplying or stopping the hydrogen gas discharged from the hydrogen generator 1.

  When the valve is closed to stop the supply of hydrogen gas in the hydrogen discharge on / off valve 15, normal hot water supply is supplied from the hot water supply device 7 to the bathtub equipment 8.

  The discharge pump 16 is a pump for sending the hydrogen gas discharged from the hydrogen generator 1 to the mixing unit 72 provided in the hot water supply piping facility. The discharge pump 16 is connected to the hydrogen generator 1 through a hydrogen discharge pipe. The hydrogen generated by the hydrogen generator 1 can be sucked by the discharge pump 16, and the hydrogen can be efficiently discharged from the hydrogen generator 1. The discharge pump 16 sends out the sucked hydrogen to the mixing unit 72 via the hydrogen discharge pipe.

  The hot water supply pump 71 is a pump for sending hot water (including water supply) discharged from the hot water supply device 7 to the bathtub facility 8 through the hot water supply pipe.

  The circulation pump 81 is a pump for sending the hot water of the bathtub provided in the bathtub facility 8 to the hot water supply device 7 when warming the hot water of the bathtub.

  The mixing unit 72 mixes hot water (or water supply) supplied via a hot water supply pipe connected from the hot water supply pump 71 and hydrogen supplied via a hydrogen discharge pipe connected from the discharge pump 16. The mixing unit 72 discharges the hot water mixed with hydrogen gas to the bathtub facility 8 through the hot water supply pipe.

  Preferably, the mixing unit 72 may have a structure that generates, for example, microbubbles (fine bubbles). The mixing part 72 has a micro bubble panel, for example. The microbubble panel is provided with a plurality of fine holes dispersed with respect to a plate shape for generating micro-order bubbles. The fine hole is provided so as to penetrate from the plate-like surface of one end of the microbubble panel to the surface of the other end. The micro bubble panel is a known metal material such as a sintered body of stainless steel, for example.

  The hydrogen gas flowing into the mixing unit 72 can be discharged from the mixing unit 72 through a plurality of fine holes of the microbubble panel. Preferably, the micropores in the microbubble panel are formed to have a pore diameter of 10 to 50 μm. In the case of supplying hydrogen to the bathtub, bubbles having a pore size of less than 10 μm tend to be too fine, and in the case of a pore size exceeding 50 μm, the effects as described later are slightly reduced as bubbles of micro-order hydrogen gas. This is because it is easy.

  In addition, the microbubble panel is arranged inside the mixing unit 72 so that the hydrogen gas discharged from the hydrogen gas inflow port blows vigorously against the surface of the one or more microbubble panels. The shape of the microbubble panel may be, for example, a flat plate shape or a hemispherical shape. Thereby, for example, hydrogen gas is vigorously discharged by the discharge pressure from the discharge pump 16, and blown onto the shape surface of the microbubble panel to form a microbubble corresponding to a pore diameter of 10 to 50 μm inside the mixing portion 72. Water containing hydrogen gas can be produced.

  As described above, according to the hot water supply system of the present embodiment, by supplying hydrogen gas as fine bubbles to the hot water supply piping route for water and hot water supply, hot water supply pipes such as water supply and hot water supply pipes and dirt components in the bathtub Since fine bubbles can enter even the uneven portions of these, there is a sterilization / cleaning effect in these pipes.

  In addition, since the bubbles are homogeneous and fine, when supplied to the hot water supply piping route for water and hot water supply, the water flow is not a turbulent flow, but a laminar flow through the flow path. Water and hot water containing gas bubbles can be supplied. Thereby, the skin beautifying effect and the cleaning effect can be expected.

  Needless to say, a further synergistic effect can be expected by combining the effect of hydrogen gas with good hydrophilicity by the hydrogen generator 1 of the third embodiment described above.

  As described above, hot water containing hydrogen gas is delivered to the bathtub provided in the bathtub facility 8. Thereby, for example, effects such as health promotion and beauty of a user who uses this bathtub are expected.

  In addition, it has a cleaning effect against dirt and dirt in the bathtub and an effect of suppressing the propagation of various germs. Further, it is possible to suppress the cleaning effect against the dirt in the pipes up to the bathtub facility 8 and the propagation of germs in the hot water supply pipes.

  Further, for example, the hot water supply facility 10 can be easily controlled from an indoor hot water supply control panel (not shown). Thereby, water and hot water containing hydrogen gas can be controlled from the hot water supply control panel, and water and hot water containing hydrogen can be easily used even at home.

  In addition, for example, the hydrogen generator 1 in the hot water supply system according to the embodiment can be installed in a board with sufficient space in the space where the hot water supply device is installed, or when installed in a space in the premises of a house. Can also save space.

  As described above, in the hot water supply system of the present embodiment, the cost reduction and space saving of the hydrogen generator 1 can be realized, so that it can be expected to be widely used at home.

[Other Embodiments]
As mentioned above, although embodiment of this invention was described, this embodiment is shown as an example and is not intending limiting the range of invention. Further, for example, this embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. For example, when an electrode catalyst using platinum is used, the electrode material for water electrolysis according to the present invention is used in order to reduce the amount of platinum used. This embodiment and its modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and their equivalents.

DESCRIPTION OF SYMBOLS 1 ... Hydrogen generator, 2, 2A, 2B, 2C ... Electrode part,
DESCRIPTION OF SYMBOLS 3 ... Power supply part 4 ... Control part 5 ... Display part 7 ... Hot-water supply apparatus 8 ... Bathtub equipment 10 ... Hot-water supply equipment 11 ... Distilled water tank 12 ... Gas-liquid separator 13 ... Drying filter 15 ... Hydrogen discharge on-off valve 16 ... Discharge pump DESCRIPTION OF SYMBOLS 22 ... Hydrogen electrode 22b, 22c ... Hydrogen electrode unit 23 ... Oxygen electrode 23b, 23c ... Oxygen electrode unit 24 ... PEM film | membrane 25 ... Hydrogen storage part 26 ... Water storage part 28 ... Ultraviolet irradiation means 30 ... Irradiation power supply 31 ... Hydrogen discharge | emission Connection part 32 ... Water discharge part 33 ... Oxygen discharge connection part 34 ... Water supply connection part 35 ... Electrode connection terminal 71 ... Hot water supply pump 72 ... Mixing part 81 ... Circulation pump 111 ... Liquid level sensor 112 ... Electrode current detection sensor 113 ... Hydrogen Pressure sensor 114 ... Hydrogen meter 220 ... Second hydrogen electrode catalyst layer 222, 232 ... Sealing plates 223, 233 ... Fine holes 230 ... Second oxygen electrode catalyst layer

Claims (8)

A hydrogen generator capable of supplying hydrogen by electrolyzing water,
An electrode part for electrolyzing water, which is formed of a sealed container capable of discharging hydrogen, and provided with a hydrogen electrode and an oxygen electrode sandwiching both sides of the electrolyte membrane in the sealed container;
A power supply unit that applies a DC voltage between the hydrogen electrode and the oxygen electrode in the electrode unit;
In the electrode material for water electrolysis used as a hydrogen electrode catalyst layer in the hydrogen electrode or an oxygen electrode catalyst layer in the oxygen electrode,
An electrode material for water electrolysis that does not contain platinum group elements of Ru, Rh, Pd, Os, Ir, and Pt,
The electrode material for water electrolysis is a molded body mainly composed of Fe or Ni, and includes a molded body containing at least Fe or Ni and a plurality of different transition metals belonging to a 3d transition metal as a metal material,
The molded body is made of a mixture containing each powder of the metal material, and the molded body is formed such that the water and hydrogen gas or oxygen gas generated by electrolyzing the water can permeate the molded body. A hydrogen generator characterized by having voids dispersed in the body. The plurality of different transition metals include at least one of Fe, Ni, Mn, Cr, or Ti belonging to the 3d transition element,
Furthermore, the molded body includes any one of Cu, Zn, Al, or Mg, which is higher in electrical conductivity than the transition metal included, as the metal material other than the transition metal included. The hydrogen generator according to claim 1. The hydrogen generation apparatus according to claim 2, wherein the plurality of different transition metals include at least Ni and Fe, Ni and Cu, or Fe and Cu. The composition ratio of the metal material in the molded body is 1 to 3 mass% for Mg, 2 to 3 mass% for Zn, or 5 to 6 mass% for Al when the mass of the molded body is 100 mass%. The hydrogen generating apparatus according to claim 3, comprising at least Ni, Fe, and Cr, the total of which is 100% by mass and subtracts mass% of the metal contained from 100% by mass. The hydrogen generating device according to any one of claims 1 to 4, wherein a porosity of the molded body is in a range of 20% to 40% with respect to a volume of the molded body. 6. The hydrogen according to claim 1, wherein in the water electrolysis electrode material, the hydrogen electrode catalyst layer or the oxygen electrode catalyst layer further contains a titanium oxide material. Generator. The hydrogen generation apparatus according to claim 6, wherein the electrode unit further includes ultraviolet irradiation means for irradiating the hydrogen electrode or the oxygen electrode with ultraviolet rays. The hydrogen generator according to any one of claims 1 to 7,
A hot water supply device capable of supplying water or hot water to the hot water supply pipe;
A discharge pump for discharging hydrogen gas from the hydrogen generator,
A hot water supply system, wherein the discharge pump mixes hydrogen gas discharged from the hydrogen generator with water or hot water supplied from the hot water supply device, and returns the mixed water to the hot water supply pipe.