JP7411920B2 - Method for manufacturing anode and cathode of electrolyzer - Google Patents

Description

The present invention relates to a method for manufacturing an anode and a cathode for an electrolyzer that chemically decomposes a predetermined aqueous solution using electricity.

The reaction tube includes a reaction tube, a catalyst body housed in the reaction tube, and a cylindrical body having a fluid inlet and a fluid outlet, the fluid inlet and the fluid outlet communicating with each other as a flow path inside the cylindrical body, and the reaction tube is placed in the flow path, the catalyst body is inserted into the reaction tube with its axis parallel to the longitudinal direction of the reaction tube, and the catalyst body includes a base material extending along a certain axis and a dehydrogenation catalyst. a dehydrogenation catalyst layer, a plate-like part extending along the axis while being twisted in a direction in which the base material rotates about the axis, and the dehydrogenation catalyst layer is provided on the surface of the plate-like part. A hydrogen generator has been disclosed (see Patent Document 1).

Japanese Patent Application Publication No. 2016-55251

The catalyst body of the hydrogen generator disclosed in Patent Document 1 includes a step of anodizing the surface of a metal molded body to form a metal oxide film containing a metal oxide, and a step of adding a dehydrogenation catalyst to the metal oxide film. It is made from a process of carrying . In the step of supporting a dehydrogenation catalyst on a metal oxide film, hexachloroplatinate (IV) ions are loaded onto the metal oxide film by bringing an acidic platinum chloride aqueous solution containing hexachloroplatinate (IV) ions into contact with the metal oxide film. At the same time, the metal oxide film to which hexachloroplatinate (IV) ions are attached is fired to cause the metal oxide film to support platinum as a dehydrogenation catalyst.

Various platinum-supported carbons are widely used as anodes and cathodes in electrolyzers. However, since platinum is a precious metal and a rare resource with limited production, there is a need to reduce its use. Furthermore, in order to popularize electrolyzers in the future, there is a need to reduce the content of expensive platinum as much as possible, and to develop anodes and cathodes that use metals other than platinum in addition to a small amount of platinum.

An object of the present invention is to provide an anode and a cathode that can minimize the content of platinum group metals and have excellent catalytic activity (catalytic action) despite the low content of platinum group metals. It is an object of the present invention to provide a method for manufacturing an anode and a cathode of an electrolyzer, which can perform electrolysis efficiently using the anode and cathode, and can generate a large amount of hydrogen gas in a short time.

The premise of the present invention for solving the above-mentioned problems is that the present invention is equipped with an anode, a cathode, and an electrode assembly membrane located between the anode and the cathode to connect the electrodes, and an electrolysis method for chemically decomposing a predetermined aqueous solution. A method of manufacturing the anode and the cathode of the device.

A feature of the present invention based on the above premise is that the method for producing an anode and a cathode is such that the total weight of the permalloy fine powder obtained by finely pulverizing Fe-Ni permalloy is such that the work function of the permalloy fine powder approximates the work function of a platinum group element. a content rate determination step of determining the content rate of Fe (iron) in the range of 45% to 55% and the content rate of Ni (nickel) to the total weight of the permalloy fine powder in the range of 45% to 55%; , finely pulverize platinum to produce a platinum group metal fine powder with a particle size of 50 nm to 80 nm, and finely pulverize Fe-Ni permalloy formed from Fe and Ni with a content determined in the content determination step to obtain a particle size of A fine powder creation process for producing permalloy fine powder with a diameter of 1 μm to 100 μm, and a weight ratio of the platinum group metal fine powder to the total weight (100%) of the mixture of platinum group metal fine powder and permalloy fine powder created by the fine powder creation process. (content rate) is determined to be in the range of 4% to 10% by weight, and the weight ratio (content rate) of the permalloy fine powder to the total weight (100%) of the body mixture is determined to be in the range of 90% to 96% by weight. At the same time, a predetermined binder and a predetermined pore-forming material are added to the platinum group metal fine powder and the permalloy fine powder at the same weight ratio, and the binder and the pore-forming material are added to the platinum group metal fine powder and the permalloy fine powder. A fine powder mixture creation step for producing a uniformly mixed and dispersed fine powder mixture, and a fine powder mixture created by the fine powder mixture creation step are put into an injection molding machine or an extrusion molding machine, and the fine powder mixture is processed by the injection molding machine. By injection molding or by extruding the fine powder mixture using an extrusion molding machine, a fine powder mixture molded product is formed from the fine powder mixture into a thin plate shape with a predetermined area and a thickness of 0.05 mm to 0.5 mm. The fine powder mixed molded product created by injection molding or extrusion molding in the fine powder mixed molded product creation process and the fine powder mixed molded product creation process are degreased, and the degreased fine powder mixed molded product is put into a firing furnace to produce fine powder. The powder mixture molded product is sintered in a firing furnace at a temperature of 900°C to 1400°C for 2 to 6 hours, and the fine powder mixture molded product is sintered into a thin plate shape with a predetermined area. After the pore-forming material foams inside the molded fine powder mixture, the pore-forming material disappears from the inside of the molded fine powder mixture, forming an anode and a cathode that are thin plate-like foamed metal electrodes with a microporous structure in which many fine continuous pores are formed. and a process for creating a thin plate-like foamed metal electrode.

As an example of the method for manufacturing the anode and cathode of the present invention, open cells formed in the anode and cathode extend irregularly in the thickness direction between the front and rear surfaces of the anode and cathode, and It extends irregularly in the radial direction between the center and the outer periphery of the anode and cathode.

As another example of the method for manufacturing the anode and cathode of the present invention, the continuous cells that are adjacent to each other in the radial direction and extend bent in the thickness direction are partially connected in the radial direction, so that one continuous cell and the other continuous cell are connected in the radial direction. The cells communicate with each other, and the continuous cells that are adjacent to each other in the thickness direction and bend and extend in the radial direction are partially connected in the thickness direction, and one continuous cell and the other continuous cell communicate with each other. The average diameter of the bubbles is not uniform in the thickness direction, but changes irregularly in the thickness direction, and is not uniform in the radial direction, but changes irregularly in the radial direction. ing.

Another example of the method for manufacturing anodes and cathodes of the present invention is that the average diameter of continuous pores formed in the anode and cathode is in the range of 1 μm to 100 μm and varies in the range of ±0.1 μm to ±5 μm. are doing.

As another example of the method for producing an anode and a cathode of the present invention, the open cells formed in the anode and cathode have a porosity in the range of 45% to 55%.

As another example of the method for manufacturing an anode and a cathode of the present invention, the density of the anode and cathode is in the range of 6.0 g/cm ² to 8.0 g/cm ² .

According to the electrolysis device of the present invention, the anode and cathode used therein are formed from a small amount of at least one platinum group metal selected from various platinum group metals and Fe-Ni permalloy. A predetermined binder is uniformly mixed and dispersed into a platinum group metal fine powder obtained by pulverizing at least one type of platinum group metal and a permalloy fine powder obtained by pulverizing Fe-Ni permalloy, and a predetermined pore forming material is uniformly mixed therein.・After dispersing and forming a fine powder mixture in which a binder and a pore-forming material are mixed into a thin plate with a predetermined area, degreasing and sintering the fine powder mixture molded into a thin plate with a predetermined area. It is a thin plate-like foamed metal electrode with a microporous structure in which many fine continuous pores are evenly formed.Platinum group metal fine powder is fixed to a permalloy melt in which permalloy fine powder is fused and bonded, and open pores are formed. Since platinum group metal fine powder is exposed on the surface of the permalloy melt that defines the Electrolysis can be efficiently carried out in an electrolyzer using the catalytic activity of platinum group metals exposed on the surface of the metal, and the fuel electrode and air electrode that utilize the catalytic activity of Fe-Ni permalloy. can generate a large amount of hydrogen gas.

In the anode and cathode, the Fe (iron) content and Ni (nickel) content in the Fe-Ni permalloy are determined so that the work function of the permalloy fine powder approximates the work function of the platinum group element. In the electrolyzer, the content of Fe and Ni in Fe-Ni permalloy is determined so that the work function of permalloy fine powder approximates that of platinum group elements, so the content of platinum group metals is low. Nevertheless, the anode and cathode have approximately the same work function as electrodes that support platinum group metals, and the anode and cathode exhibit approximately the same excellent catalytic activity (catalytic action) as electrodes that support platinum group metals. However, electrolysis can be efficiently carried out in an electrolysis device by using the catalytic activity of platinum group metals exposed on the surface of the permalloy melt and by using an anode and a cathode that utilize the catalytic activity of Fe-Ni permalloy. , it is possible to generate a large amount of hydrogen gas in a short time.

Open cells formed in the anode and cathode extend irregularly in the thickness direction between the front and rear surfaces of the anode and cathode, and in the radial direction between the center and outer periphery of the anode and cathode. In an electrolysis device that extends irregularly, the open cells extend irregularly in the thickness direction and radial direction, so it is possible to increase the specific surface area of the anode and cathode. By allowing the liquid (water) to flow through the pores, the liquid can be brought into contact with the contact surfaces of the anode and cathode over a wide range, and the catalytic action of the anode and cathode can be utilized to the fullest. The anode and cathode used in an electrolysis device have excellent catalytic activity (catalytic action), and the anode and cathode are brought into contact with the liquid (water) over a wide area to maximize the catalytic action of the anode and cathode. Therefore, electrolysis can be efficiently performed in an electrolyzer using the anode and cathode, and a large amount of hydrogen gas can be generated in a short time.

These open cells that are adjacent in the radial direction and extend bent in the thickness direction are partially connected in the radial direction, so that one open cell and the other open cell communicate with each other, and the open cells are adjacent in the thickness direction and bend in the radial direction. The continuous cells that extend in the thickness direction are partially connected in the thickness direction, and one continuous cell and the other continuous cell communicate with each other, and the average diameter of the continuous cells is not uniform in the thickness direction. The electrolyzer, which changes irregularly in the radial direction and is not uniform in the radial direction, has open cells on one side and open cells on the other side in the radial and thickness directions. The open cells communicate with each other, and the average diameter of the open cells changes irregularly in the thickness direction and the radial direction, so the specific surface area of the anode and cathode can be increased. By flowing the liquid (water), the liquid can be brought into contact with the contact surfaces of the anode and cathode over a wide range, and the catalytic action of the anode and cathode can be utilized to the maximum. The anode and cathode used in an electrolysis device have excellent catalytic activity (catalytic action), and the anode and cathode are brought into contact with the liquid (water) over a wide area to maximize the catalytic action of the anode and cathode. Therefore, electrolysis can be efficiently performed in an electrolyzer using the anode and cathode, and a large amount of hydrogen gas can be generated in a short time.

An electrolyzer in which the average diameter of continuous pores formed in the anode and cathode is in the range of 1 μm to 100 μm and varies in the range of ±0.1 μm to ±5 μm, Since the average diameter of the anode and cathode is in the range of 1 to 100 μm and varies in the range of ±0.1 μm to ±5 μm, a large number of continuous pores are formed per unit volume of the anode and cathode, and the specific surface area of the anode and cathode is By allowing the liquid (water) to flow through these pores, the liquid can be brought into contact with the contact surfaces of the anode and cathode over a wide range, and the catalytic action of the anode and cathode can be utilized to the maximum. Can be done. The anode and cathode used in an electrolysis device have excellent catalytic activity (catalytic action), and the anode and cathode are brought into contact with the liquid (water) over a wide area to maximize the catalytic action of the anode and cathode. Therefore, electrolysis can be efficiently performed in an electrolyzer using the anode and cathode, and a large amount of hydrogen gas can be generated in a short time.

In an electrolyzer in which the thickness of the anode and cathode is in the range of 0.05 mm to 0.5 mm, the electrical resistance of the anode and cathode can be reduced by setting the thickness of the anode and cathode within the above range, Current can flow smoothly through the anode and cathode. The anode and cathode used in an electrolyzer have excellent catalytic activity (catalytic action) almost the same as electrodes supporting platinum group elements, and current flows smoothly through the anode and cathode (proton conductivity). ), electrolysis can be performed efficiently in an electrolyzer using an anode and a cathode, and a large amount of hydrogen gas can be generated in a short time.

The content of Fe in Fe-Ni permalloy is in the range of 45% to 55%, the content of Ni in Fe-Ni permalloy is in the range of 45% to 55%, and platinum group metal fine powder and permalloy fine powder are mixed. The weight ratio of the platinum group metal fine powder to the total weight of the fine powder mixture is in the range of 4% to 10% by weight, and the permalloy fine powder is based on the total weight of the fine powder mixture in which the platinum group metal fine powder and the permalloy fine powder are mixed. An electrolyzer in which the weight ratio of Fe-Ni permalloy is in the range of 90% to 96% by weight is such that the content of Fe and Ni in Fe-Ni permalloy is adjusted so that the work function of the permalloy fine powder approximates the work function of platinum group elements. is defined in the above range, the anode and cathode have approximately the same work function as the electrode supporting the platinum group element, even though the content of the platinum group element is small, and the anode and cathode used in the electrolyzer are It is possible to exhibit approximately the same excellent catalytic activity (catalytic action) as an electrode in which a platinum group element is supported on the cathode. In the electrolyzer, the weight ratio of the platinum group metal fine powder to the total weight of the fine powder mixture is within the above range, and the content of expensive platinum group metals in the anode and cathode is low, reducing material costs for the anode and cathode. Therefore, the electrolyzer can be manufactured at low cost. Since an electrolyzer exhibits excellent catalytic activity (catalytic action) that is almost the same as an electrode in which an anode and a cathode support a platinum group metal, electrolysis can be carried out efficiently in an electrolyzer that uses an anode and a cathode. It is possible to generate a large amount of hydrogen gas in a short period of time.

An electrolyzer in which the porosity of the open cells formed in the anode and cathode is in the range of 45% to 55% can be manufactured by setting the porosity of the anode and cathode within the above range. It is formed into a porous material with pores (a microporous structure in which fine continuous pores with an average diameter of 1 μm to 100 μm are uniformly formed), and the specific surface area of the anode and cathode can be increased, and the continuous pores can be This makes it possible to bring the liquid into contact with the contact surfaces of the anode and cathode over a wide area while flowing water (water), making it possible to make maximum use of the catalytic action of the anode and cathode. It is possible to reliably exhibit substantially the same catalytic activity (catalytic action) as an electrode in which a platinum group metal is supported on the cathode.

An electrolyzer in which the density of the anode and cathode is in the range of 6.0 g/cm ² to 8.0 g/cm ² can be used by setting the density of the anode and cathode within the above range. It is formed into a porous material with pores (a microporous structure in which fine continuous pores with an average diameter of 1 μm to 100 μm are uniformly formed), and the specific surface area of the anode and cathode can be increased, and the continuous pores can be This makes it possible to bring the liquid into contact with the contact surfaces of the anode and cathode over a wide area while flowing water (water), making it possible to make maximum use of the catalytic action of the anode and cathode. It is possible to reliably exhibit substantially the same catalytic activity (catalytic action) as an electrode in which a platinum group metal is supported on the cathode.

An electrolyzer in which the particle size of the permalloy fine powder is in the range of 1 μm to 100 μm and the particle size of the platinum group metal fine powder is in the range of 50 nm to 80 nm, by setting the particle size of the permalloy fine powder in the above range, The anode and cathode are formed in a porous structure with many fine continuous pores (a microporous structure in which fine continuous pores with an average diameter of 1 μm to 100 μm are uniformly formed), increasing the specific surface area of the anode and cathode. This makes it possible to allow liquid (water) to flow through these continuous pores and bring the liquid into contact with the contact surfaces of the anode and cathode over a wide area, making it possible to make maximum use of the catalytic action of the anode and cathode. , it is possible to reliably exhibit substantially the same catalytic activity (catalytic action) as an electrode in which a platinum group metal is supported on the anode and cathode used in an electrolyzer.

FIG. 2 is a side view of an electrolyzer shown as an example. FIG. 2 is a perspective view of an anode and a cathode shown as an example. The partially enlarged view shown as an example of an anode and a cathode. The figure explaining an example of electrolysis using an electrolysis device. FIG. 1 is a diagram showing an example of a hydrogen gas generation system using an electrolyzer. 1 is a side view of a polymer electrolyte fuel cell using an air electrode (anode) and a fuel electrode (cathode). The figure which shows the result of the electromotive force test of an anode and a cathode. The figure which shows the result of the IV characteristic test of an anode and a cathode. FIG. 2 is a diagram illustrating a method for manufacturing an anode (air electrode) and a cathode (fuel electrode) used in an electrolyzer and a polymer electrolyte fuel cell.

The details of the electrolyzer and the method for manufacturing the anode and cathode used in the electrolyzer according to the present invention will be described below with reference to the accompanying drawings such as FIG. 1, which is a side view of an electrolyzer 10 shown as an example. It is as follows. 2 is a perspective view of the anode 11 and the cathode 12 shown as an example, and FIG. 3 is a partially enlarged view of the anode 11 and the cathode 12 shown as an example. In FIG. 2, the thickness direction is indicated by an arrow X, and the radial direction is indicated by an arrow Y.

The electrolyzer 10 (hydrogen gas generator) includes an anode 11 (anode), a cathode 12 (cathode), and a solid polymer electrolyte membrane 13 (electrode assembly membrane) located (interposed) between the anode 11 and the cathode 12. ) (a fluorine-based ion exchange membrane having a sulfonic acid group), an anode power supply member 14, a cathode power supply member 15, an anode water tank 16, a cathode water tank 17, an anode main electrode 18, and a cathode main electrode 19. It is formed.

The electrolyzer 10 applies electricity to an anode 11 and a cathode 12 to cause an oxidation reaction at the anode 11 and a reduction reaction at the cathode 12 to chemically decompose a predetermined aqueous solution. In the electrolyzer 10, an anode 11, a cathode 12, and a solid polymer electrolyte membrane 13 are overlapped and integrated in the thickness direction to form a membrane/electrode assembly (MEA). is sandwiched between the anode power supply member 14 and the cathode power supply member 15. In the membrane/electrode assembly 20, the surface of the anode 11 is brought into close contact with one surface of the solid polymer electrolyte membrane 13 without any gaps by hot pressing, and the surface of the cathode 12 is brought into close contact with the other surface of the solid polymer electrolyte membrane 13 without any gaps. It's in close contact. The solid polymer electrolyte membrane 13 has proton conductivity and no electronic conductivity.

The anode power supply member 14 is located outside the anode 11 and in close contact with the anode 11, and supplies positive current to the anode 11. The anode water tank 16 is located outside the anode power supply member 14 and is in close contact with the anode power supply member 14 . The anode main electrode 18 is located outside the anode water tank 16 and supplies positive current to the anode power supply member 14 . The cathode power supply member 15 is located outside the cathode 12 and in close contact with the cathode 12, and supplies negative current to the cathode 12. The cathode water tank 17 is located outside the cathode power supply member 15 and is in close contact with the cathode power supply member 15 . The cathode main electrode 19 is located outside the cathode water tank 17 and supplies negative current to the cathode power supply member 15 .

The anode 11 and the cathode 12 used in the electrolyzer 10 (hydrogen gas generator) have a front surface 21 and a rear surface 22, a predetermined area and a predetermined thickness L1, and have a rectangular planar shape. ing. The anode 11 and the cathode 12 are porous (microporous structure) thin plate-shaped foamed metal electrodes 24 having a large number of fine pores 23 (continuous and independent passage pores). An aqueous solution (liquid) flows through the pores 23 . Note that there is no particular restriction on the planar shape of the anode 11 or the cathode 12, and in addition to the square shape, the anode 11 and the cathode 12 can be formed into any other planar shape such as a circle or an ellipse depending on the intended use.

The anode 11 and the cathode 12 (thin plate-like foamed metal electrodes 24 with a microporous structure) are made of a platinum group metal 49 that has been finely pulverized (pulverized) into powder and Fe-Ni that has been pulverized (pulverized) into powder. It is made of Permalloy 50. As the platinum group metal 49, platinum (Pt), palladium (Pb), rhodium (Rh), ruthenium (Ru), iridium (Ir), and osmium (Os) can be used. At least one of them is used for the platinum group metal 49.

Platinum group metal fine powder 51 of platinum group metal 49 (Pt (platinum) crushed into fine powder, Pb (palladium) crushed into fine powder, Rh (rhodium) crushed into fine powder, fine powder) Permalloy fine powder 52 (Ru (ruthenium) crushed into fine powder, Ir (iridium) crushed into fine powder, Os (osmium) crushed into fine powder) and Fe-Ni Permalloy 50 (pulverized into fine powder) Processed Fe-Ni permalloy 52) is mixed with a predetermined binder 53 (powdered resin binder), and platinum group metal fine powder 51, permalloy fine powder 52, and binder 53 are uniformly mixed and dispersed. A predetermined pore-forming material 54 (foaming agent) is further mixed with the fine powder mixture 55 to produce a fine powder mixture 55 in which the pore-forming material 54 is uniformly mixed and dispersed. The prepared fine powder mixture 55 is molded into a thin plate with a predetermined area (extrusion molding or injection molding) to produce a thin plate-shaped fine powder mixture molded product 56, and the prepared fine powder mixed molded product 56 is degreased and baked at a predetermined temperature. By sintering (firing), an anode 11 and a cathode 12 (thin foam metal electrode 24) are produced (see FIG. 9). The platinum group metal fine powder 51 is fixed to the permalloy melt to which the permalloy fine powder 52 is fused and bonded, and is exposed on the surface of the permalloy melt defining and surrounding the open cells 23.

In the anode 11 and the cathode 12, the Fe content (weight ratio) and the Ni content (weight ratio) in the Fe-Ni permalloy 50 are adjusted such that the work function of the permalloy fine powder 52 approximates the work function of the platinum group element. has been determined. Specifically, the content of Fe (iron) in Fe-Ni permalloy 50 is in the range of 45% to 55%, preferably in the range of 49% to 51%, and The content is in the range of 45% to 55%, preferably in the range of 49% to 51%.

Note that the work function of platinum is 5.65 (eV), the work function of Fe is 4.67 (eV), and the work function of Ni is 5.22 (eV). When the content of Fe in the Fe-Ni permalloy 50 and the content of Ni in the Fe-Ni permalloy 50 are outside the above range, the work function of the permalloy fine powder 52 cannot be approximated to the work function of the platinum group element, The anode 11 and cathode 12 (thin foam metal electrode 24) made by degreasing and sintering (firing) the fine powder mixture molded product 56 formed from the fine powder mixture 55 are substantially similar to electrodes supporting platinum group elements. cannot exhibit catalytic activity (catalytic action).

The weight ratio (content rate) of the platinum group metal fine powder 51 to the total weight (100%) of the fine powder mixture 55, which is a mixture of the platinum group metal fine powder 51 and the permalloy fine powder 52, is 4% to 10% by weight. range, preferably in the range of 5% to 8% by weight, and the weight of the permalloy fine powder 52 relative to the total weight (100%) of the fine powder mixture 55 in which the platinum group metal fine powder 51 and the permalloy fine powder 52 are mixed. The ratio (content) is in the range 90% to 96% by weight, preferably in the range 92% to 95% by weight. The weight ratio of the platinum group metal fine powder 51 to the total weight of the fine powder mixture 55 that is a mixture of the platinum group metal fine powder 51 and the permalloy fine powder 52, and the fine powder that is the mixture of the platinum group metal fine powder 51 and the permalloy fine powder 52. If the weight ratio of the permalloy fine powder 52 to the total weight of the mixture 55 is outside the above range, the anode 11 and cathode made by degreasing and sintering (firing) the fine powder mixture molded product 56 formed from the fine powder mixture 55. 12 (thin plate-shaped foamed metal electrode 24) cannot exhibit substantially the same catalytic activity (catalytic action) as an electrode supporting a platinum group element.

A large number of fine continuous pores 23 (continuous ventilation holes) having different diameters are formed in the anode 11 and the cathode 12 (thin foam metal electrode 24). Since the anode 11 and the cathode 12 have a large number of fine continuous pores 23 formed therein, their specific surface area is large. The continuous pores 23 formed in the anode 11 and the cathode 12 (thin foam metal electrode 24) have a plurality of communication ports 25 opening on the front surface 21 of the anode 11 and the cathode 12, and a rear surface 22 of the anode 11 and the cathode 12. It has a plurality of communication holes 25 that open to the anode 11 and the cathode 12, and penetrates the anode 11 and the cathode 12 in the thickness direction from the front surface 21 of the anode 11 and the cathode 12 toward the rear surface 22. It penetrates in the radial direction from the center toward the outer peripheral edge 26.

These continuous pores 23 extend between the front surface 21 and the rear surface 22 of the anode 11 and the cathode 12 while being irregularly bent in the thickness direction of the anode 11 and the cathode 12, and the outer periphery 23 of the anode 11 and the cathode 12 It extends from the center toward the center in the radial direction of the anode 11 and cathode 12 while being irregularly bent. The continuous pores 23 (continuous vents) that are adjacent to each other in the radial direction and extend bent in the thickness direction are partially connected in the radial direction, and one pore 23 and the other pore 23 are in communication with each other. The continuous pores 23 (continuous vents) that are adjacent to each other in the thickness direction and bend and extend in the radial direction are partially connected in the thickness direction, and one pore 23 and the other pore 23 are in communication with each other.

The average diameter (opening area) of these continuous pores 23 is not uniform in the thickness direction, but changes irregularly in the thickness direction, and is not uniform in the radial direction, but in the radial direction. It is changing irregularly. These continuous pores 23 open irregularly in the thickness direction and the radial direction, with the average diameter (opening area) increasing or decreasing. Furthermore, the average diameters (opening areas) of the communication ports 25 that open on the front surface 21 of the anode 11 and the cathode 12 and the communication ports 25 that open on the rear surface 22 are not uniform, and the average diameters are all different. ing. The average diameter (opening area) of the continuous pores 23 and the average diameter (opening area) of the communication ports 25 on the front and rear surfaces 21 and 22 are in the range of 1 μm to 100 μm, preferably in the range of 45 μm to 55 μm, ±0 It varies within a range of .1 μm to ±5 μm (width of change in average diameter of continuous pores 23).

The electrolyzer 10 has a plurality of continuous pores 23 (continuous ventilation pores) formed in the anode 11 and cathode 12 that extend irregularly in the thickness direction and radial direction, and the average diameter of the pores 23 is 1. 100 μm (preferably 45 μm to 55 μm), and the variation width of the average diameter of continuous pores 23 is within ±0.1 μm to ±5 μm. A large number of continuous pores 23 are formed, and the specific surface area of the anode 11 and the cathode 12 can be increased, and while liquid (water) flows through these pores 23, the liquid is transferred to the contact surface of the anode 11 and the cathode 12 at the pores 23. The catalytic activity (catalytic action) of the anode 11 and the cathode 12 can be effectively and maximally utilized.

The thickness L1 of the anode 11 and the cathode 12 (thin foam metal electrode 24 with a microporous structure) is in the range of 0.05 mm to 0.5 mm. If the thickness dimension L1 of the anode 11 and the cathode 12 is less than 0.05 mm, the strength of the anode 11 and the cathode 12 will decrease, and the anode 11 and the cathode 12 will be easily damaged or destroyed when an impact is applied, and the shape of the anode 11 and the cathode 12 will be deteriorated. It may not be possible to maintain it. If the thickness dimension L1 of the anode 11 and the cathode 12 exceeds 0.5 mm, the electrical resistance of the anode 11 and the cathode 12 will increase, and current will not flow smoothly through the anode 11 and the cathode 12 (proton conductivity is low). When the electrolyzer 11 and the cathode 12 are used in the electrolyzer 10, electrolysis cannot be performed efficiently in the electrolyzer 10, and a large amount of hydrogen gas cannot be generated in a short time.

Since the thickness L1 of the anode 11 and cathode 12 used in the electrolyzer 10 is in the range of 0.05 mm to 0.5 mm, the anode 11 and cathode 12 have high strength and maintain their shape. This can prevent the anode 11 and the cathode 12 from being damaged or destroyed when a shock is applied to the anode 11 and the cathode 12. Furthermore, the electrical resistance of the anode 11 and the cathode 12 can be reduced, current flows smoothly through the anode 11 and the cathode 12 (high proton conductivity), and the anode 11 and the cathode 12 can be used in the electrolyzer 10. Sometimes, electrolysis can be performed efficiently in the electrolyzer 10, and a large amount of hydrogen gas can be generated in a short time.

The anode 11 and the cathode 12 (thin foam metal electrode 24 with a microporous structure) have a porosity in the range of 45% to 55%. If the porosity of the anode 11 and the cathode 12 is less than 45%, many fine continuous pores 23 (continuous vents) are not formed in the anode 11 and the cathode 12, and the specific surface area of the anode 11 and the cathode 12 cannot be increased. Can not. When the porosity of the anode 11 and the cathode 12 exceeds 55%, the average diameter (opening area) of the continuous pores 23 (continuous ventilation holes) and the average diameter (opening area) of the communication ports 25 on the front and rear surfaces 21 and 22 are required. If the anode 11 and the cathode 12 become larger than the The catalytic activity of the anode 11 and the cathode 12 is reduced, the anode 11 and the cathode 12 cannot exhibit sufficient catalytic activity, and the catalytic activity (catalytic action) of the anode 11 and the cathode 12 cannot be used effectively.

Since the porosity of the anode 11 and the cathode 12 used in the electrolyzer 10 is within the above range, the anode 11 and the cathode 12 have a large number of fine continuous pores 23 (with an average diameter of 1 Continuous pores 23 in the range of ~100 μm, preferably in the range of 45 μm to 55 μm) and a large number of fine ventilation holes 25 in the front and rear surfaces 21 and 22 with different average diameters (opening areas) (in the range of 1 to 100 μm in average diameter) The anode 11 and the cathode 12 are preferably formed into a porous structure (microporous structure) having a through hole 25 in the range of 45 μm to 55 μm. ) can be brought into wide contact with the contact surfaces of the pores 23 of the anode 11 and cathode 12 while flowing through the liquid. Furthermore, the catalytic action of the anode 11 and the cathode 12 is improved, and the anode 11 and the cathode 12 can exhibit excellent catalytic activity, and when the anode 11 and the cathode 12 are used in the electrolyzer 10, 10, electrolysis can be performed efficiently and a large amount of hydrogen gas can be generated in a short time.

The anode 11 and the cathode 12 (thin foam metal electrode 24 with a microporous structure) have a density in the range of 6.0 g/cm ² to 8.0 g/cm ² , preferably 6.5 g/cm ² to 7.0 g/cm 2 . It is in the range of 5g/ ^cm2 . If the density of the anode 11 and the cathode 12 is less than 6.0 g/cm ² (6.5 g/cm ² ), the strength of the anode 11 and the cathode 12 will decrease, and the anode 11 and the cathode 12 will easily break when an impact is applied. In some cases, the anode 11 and the cathode 12 are damaged or destroyed, and cannot maintain their shape, and the catalytic action of the anode 11 and the cathode 12 decreases, making it impossible for the anode 11 and the cathode 12 to exhibit sufficient catalytic activity. The catalytic activity (catalytic action) of the cathode 11 and the cathode 12 cannot be used effectively. When the density of the anode 11 and the cathode 12 exceeds 8.0 g/cm ² (7.5 g/cm ² ), many fine continuous pores 23 and many fine communication holes 25 are formed in the anode 11 and the cathode 12. Therefore, the specific surface area of the anode 11 and the cathode 12 cannot be increased, and the catalytic action of the anode 11 and the cathode 12 is reduced, and the anode 11 and the cathode 12 are unable to exhibit sufficient catalytic activity. The catalytic activity (catalytic action) of the cathode 11 and the cathode 12 cannot be used effectively.

Since the density of the anode 11 and the cathode 12 used in the electrolyzer 10 is within the above range, the anode 11 and the cathode 12 have a large number of fine continuous pores 23 (with an average diameter of 1 to 1) having different average diameters (opening areas). Continuous pores 23 in the range of 100 μm, preferably in the range of 45 μm to 55 μm) and a large number of fine flow holes 25 on the front and rear surfaces 21 and 22 with different average diameters (opening areas) (in the range of 1 to 100 μm in average diameter, Preferably, the anode 11 and the cathode 12 are formed into a porous structure (microporous structure) having a through hole 25) in the range of 45 μm to 55 μm, so that the specific surface area of the anode 11 and the cathode 12 can be increased. The liquid can be widely brought into contact with the contact surfaces of the pores 23 of the anode 11 and the cathode 12 while flowing, and the catalytic action of the anode 11 and the cathode 12 can be effectively and maximally utilized. Furthermore, the catalytic action of the anode 11 and the cathode 12 is improved, and the anode 11 and the cathode 12 can exhibit excellent catalytic activity, and when the anode 11 and the cathode 12 are used in the electrolyzer 10, 10, electrolysis can be performed efficiently and a large amount of hydrogen gas can be generated in a short time.

The particle size of the permalloy fine powder 52 (Fe-Ni permalloy 50 processed into powder) is in the range of 1 μm to 100 μm, preferably in the range of 30 μm to 60 μm. Platinum group metal fine powder 51 (Pt fine powder (powdered Pt), Pb fine powder (powdered Pb), Rh fine powder (powdered Rh), Ru The particle size of the fine powder of Ru (Ru processed into powder), the fine powder of Ir (Ir processed into powder), and the fine powder of Os (Os processed into powder) is 50 nm to 80 nm. in range.

If the particle size of the permalloy fine powder 52 is less than 1 μm, the continuous pores 23 (continuous ventilation pores) are blocked by the permalloy fine powder 42, and a large number of fine continuous pores 23 cannot be formed in the anode 11 and the cathode 12. , the specific surface area of the anode 11 and the cathode 12 cannot be increased, and the catalytic action of the anode 11 and the cathode 12 is reduced, and the anode 11 and the cathode 12 cannot exhibit sufficient catalytic activity. The catalytic activity (catalytic action) of the cathode 12 cannot be effectively utilized. When the particle size of the permalloy fine powder 52 exceeds 100 μm, the average diameter (opening area) of the continuous pores 23 and the average diameter (opening area) of the communication ports 25 on the front and rear surfaces 21 and 22 become larger than necessary, and the anode 11 It is not possible to form many fine continuous pores 23 in the cathode 12, and the specific surface area of the anode 11 and the cathode 12 cannot be increased, and the catalytic action of the anode 11 and the cathode 12 is reduced, The cathode 12 cannot exhibit sufficient catalytic activity, and the catalytic activity (catalytic action) of the anode 11 and the cathode 12 cannot be effectively utilized.

In the electrolyzer 10, since the particle size of the permalloy fine powder 52 forming the anode 11 and the cathode 12 is within the above range, the anode 11 and the cathode 12 have a large number of fine continuous pores 23 (with different average diameters (opening areas)). Continuous pores 23 with an average diameter in the range of 1 to 100 μm, preferably 45 μm to 55 μm) and a large number of fine flow holes 25 in the front and rear surfaces 21 and 22 with different average diameters (opening areas) (with an average diameter of 1 to 55 μm) It is formed into a porous structure (microporous structure) having a through hole 25) in the range of ~100 μm, preferably in the range of 45 μm to 55 μm, and the specific surface area of the anode 11 and cathode 12 can be increased. While the liquid (water) is flowing through the liquid, the liquid can be widely contacted with the contact surfaces of the pores 23 of the anode 11 and the cathode 12, and the catalytic activity (catalytic action) of the anode 11 and the cathode 12 can be effectively and maximized. can be used. Furthermore, the catalytic action of the anode 11 and the cathode 12 is improved, and the anode 11 and the cathode 12 can exhibit excellent catalytic activity, and when the anode 11 and the cathode 12 are used in the electrolyzer 10, 10, electrolysis can be performed efficiently and a large amount of hydrogen gas can be generated in a short time.

A specific example of the platinum group metal 31 used for the anode 11 and the cathode 12 (microporous thin plate foam metal electrode 24) is platinum 49 (Pt) processed into powder, as shown in FIG. Group metal fine powder 51 (particle size: 50 nm to 80 nm) is used. A fine powder mixture 55 is prepared by uniformly mixing and dispersing a predetermined binder 53 and a predetermined pore forming material 54 (foaming agent) in fine powders 51 and 52 of platinum 49 and Fe-Ni permalloy 50, and the fine powder mixture 55 By extrusion molding or injection molding to form a thin plate of a predetermined area to create a thin plate-shaped fine powder mixture molded product 56, and degrease the fine powder mixture molded product 56 and sinter (fire) it at a predetermined temperature. , a large number of fine continuous pores 23 (continuous pores 23 with an average diameter in the range of 1 to 100 μm, preferably in the range of 45 μm to 55 μm) are formed, and permalloy fine powder 52 is fused and bonded to the permalloy melt. The platinum group metal fine powder 51 is fixed and formed into a thin plate-shaped foamed metal electrode 24 having a microporous structure in which the platinum group metal fine powder 52 is exposed on the surface of the permalloy melt defining and surrounding the open cells 23.

FIG. 4 is a diagram illustrating an example of electrolysis using the electrolyzer 10, and FIG. 5 is a diagram illustrating an example of a hydrogen gas generation system 27 using the electrolyzer 10. In the electrolysis shown in FIG. 4, water ( _aqueous solution) is electrolyzed to generate hydrogen and oxygen. Electrolysis of ₂ SO ₄ aqueous solution, NaCl aqueous solution, AgNO ₃ aqueous solution, and CuSO ₄ aqueous solution is performed.

During water electrolysis in the electrolyzer 10, water (H ₂ O) is supplied to the anode water tank 16 and the cathode water tank 17, as shown by arrows in FIG. At the same time, a negative current is supplied to the cathode main electrode 19 from the power source. The + current supplied to the anode main electrode 18 is supplied from the anode power supply member 14 to the anode 11 (anode), and the - current supplied to the cathode main electrode 19 is supplied from the cathode power supply member 15 to the cathode 12 (cathode). be done.

At the anode 11 (electrode), oxygen is generated by the anodic reaction (catalytic action) of 2H ₂ O → 4H ⁺ +4e ^- +O ₂ , and at the cathode 12 (electrode), the cathodic reaction (catalytic action) of 4H ⁺ +4e ^- →2H ₂ ) produces hydrogen. Protons (hydrogen ions: H ⁺ ) pass through the solid polymer electrolyte membrane 13 and move from the anode 11 to the cathode 12 (electrode). Protons generated at the anode 11 flow through the solid polymer electrolyte membrane 12 .

The electrolyzer 10 includes an anode 11 (electrode) and a cathode 12 (electrode) containing platinum group metal fine powder 37 (particle size: 50 nm to 80 nm) obtained by finely pulverizing Pt (platinum) (platinum group metal), and further, The Fe content (weight ratio) and Ni content (weight Since the anode 11 and the cathode 12 have approximately the same work function as an electrode supporting a platinum group element (platinum), they have approximately the same performance as an electrode supporting a platinum group element (platinum). It exhibits catalytic activity (catalytic action), and water electrolysis progresses efficiently.

In the electrolysis of NaOH aqueous solution, an anodic reaction (catalytic action) of 4OH ^- →2H ₂ O+O ₂ +4e ^- occurs at the anode 11, and a cathodic reaction (catalytic action) of 2H ₂ O+2e ^- →2OH ^- +H ₂ occurs at the cathode 12. happens. In the electrolysis of H ₂ SO ₄ aqueous solution, an anodic reaction (catalytic action) of 2H ₂ O → O ₂ +4H ⁺ +4e ^- occurs at the anode 11, and a cathodic reaction (catalytic action) of 2H ⁺ +2e ^- → H ₂ occurs at the cathode 12. happens.

In the electrolysis of an aqueous NaCl solution, an anodic reaction (catalytic action) of 2Cl ⁻ →Cl ₂ +2e ⁻ occurs at the anode 11, and a cathodic reaction (catalytic action) of 2H ₂ O+2e ⁻ →2OH ⁻ +H ₂ occurs at the cathode 12. In the electrolysis of the AgNO ₃ aqueous solution, an anodic reaction (catalytic action) of 2H ₂ O→O ₂ +4H ⁺ +4e ⁻ occurs at the anode 11, and a cathodic reaction (catalytic action) of Ag ⁺ +e ⁻ →Ag occurs at the cathode 12. In the electrolysis of the CuSO ₄ aqueous solution, an anodic reaction (catalytic action) of 2H ₂ O→O ₂ +4H ⁺ +4e ⁻ occurs at the anode 11, and a cathodic reaction (catalytic action) of Cu ²⁺ +2e ⁻ →Cu occurs at the cathode 12.

The hydrogen gas generation system 27 includes an electrolyzer 10, a DC power supply 28 that supplies electricity to the anode 11 and cathode 12 of the electrolyzer 10, a water storage tank 29 that stores water (pure water), and a water storage tank 29 that stores water (pure water). a water supply pump 30 that supplies water), an oxygen gas-liquid separator 31, two circulation pumps 32 and 33 that supplies water (pure water), a hydrogen gas-liquid separator 34, and a cylinder 35 that stores hydrogen ( hydrogen tank).

In the hydrogen gas generation system 27, water (pure water) stored in a water storage tank 29 is supplied to an oxygen gas-liquid separator 31 by a water supply pump 30, and water flowing out from the oxygen gas-liquid separator 31 is supplied to the electrolyzer 10. Water is supplied. Electricity is supplied from the DC power supply 28 to the electrolyzer 10, and water is decomposed into hydrogen and oxygen by electrolysis performed in the electrolyzer 10. Oxygen flows into the oxygen gas-liquid separator 31, is separated into gas and liquid, and then released into the atmosphere. The water separated into gas and liquid in the oxygen gas-liquid separator 31 is supplied to the electrolyzer 10 again by the circulation pump 32. Hydrogen flows into the hydrogen gas-liquid separator 34, where it is separated into gas and liquid, and then flows into the cylinder 35 (hydrogen tank). The water separated into gas and liquid in the hydrogen gas-liquid separator 34 is supplied to the electrolyzer 10 again by the circulation pump 33.

The electrolyzer 10 (hydrogen gas generation system 27) has an anode 11 and a cathode 12 made of a small amount of at least one platinum group metal 49 (platinum 49) selected from various platinum group metals and Fe-Ni. A predetermined binder 53 is uniformly applied to a platinum group metal fine powder 51 which is formed by finely pulverizing at least one selected platinum group metal 49 and a permalloy fine powder 52 which is formed by finely pulverizing Fe-Ni permalloy 50. After uniformly mixing and dispersing a predetermined pore-forming material 54, and forming a fine powder mixture 55 in which a binder 53 and a pore-forming material 54 are mixed into the fine powders 51 and 52 into a thin plate having a predetermined area. By degreasing and sintering a fine powder mixture molded product 56 formed into a thin plate shape with a predetermined area, it is a thin plate-shaped foamed metal electrode 24 with a microporous structure in which a large number of fine continuous pores 23 are evenly and uniformly formed. , the platinum group metal fine powder 51 is fixed to the permalloy melt to which the permalloy fine powder 52 is fused and bonded, and the platinum group metal fine powder 51 is exposed on the surface of the permalloy melt defining and surrounding the open cells 23. Furthermore, the Fe content (weight ratio) and the Ni content (weight ratio) in the Fe-Ni permalloy 50 are determined so that the work function of the permalloy fine powder 52 approximates the work function of the platinum group element. Therefore, the anode 11 and cathode 12 have approximately the same work function as an electrode supporting a platinum group metal (platinum), and the anode 11 and cathode 12 have excellent catalytic activity (catalytic action). Since the cathode 12 exhibits substantially the same catalytic activity (catalytic action) as an electrode supporting a platinum group metal (platinum), electrolysis can be carried out efficiently using the anode 11 and cathode 12, and in a short period of time. A large amount of hydrogen gas can be generated in a short amount of time.

The electrolyzer 10 (hydrogen gas generation system 27) uses the anode 11 and cathode 12 mainly composed of Fe-Ni permalloy 50 and has a low content of platinum group metal 49, so the material of the anode 11 and cathode 12 is The cost can be reduced, the electrolyzer 10 (hydrogen gas generation system 27) can be manufactured at low cost, and the operating cost of the electrolyzer 10 (hydrogen gas generation system 27) can be lowered.

FIG. 6 is a side view of a polymer electrolyte fuel cell 36 using an air electrode 38 (anode 11) and a fuel electrode 37 (cathode 12), and FIG. 7 shows an anode 11 (air electrode 38) and a cathode 12 ( It is a figure which shows the result of the electromotive force test of fuel electrode 37). FIG. 8 is a diagram showing the results of an IV characteristic test of the anode 11 (air electrode 38) and the cathode 12 (fuel electrode 37). Although FIG. 6 shows a state in which the load 48 is connected, in the electromotive force test, the load 48 does not exist and there is no load. In the electromotive voltage test and the IV characteristic test, the anode 11 (air electrode 38) and cathode 12 (fuel electrode 37) used in the electrolyzer 10 were used in the polymer electrolyte fuel cell 36 shown in FIG. The electromotive voltage at the load was measured, the load 48 was connected to the polymer electrolyte fuel cell 36, and its IV characteristics were measured.

As shown in FIG. 6, the polymer electrolyte fuel cell 36 includes a fuel electrode 37 (cathode 12), an air electrode 38 (anode 11), and a solid height located (interposed) between the fuel electrode 37 and the air electrode 38. A molecular electrolyte membrane 39 (electrode assembly membrane) (a fluorine-based ion exchange membrane having sulfonic acid groups), a separator 40 (bipolar plate) located on the outside in the thickness direction of the fuel electrode 37, and a separator 40 (bipolar plate) located on the outside in the thickness direction of the air electrode 38. It is formed from a separator 41 (bipolar plate) located thereon.

The separators 40 and 41 are carved with flow paths for supplying reactive gases (hydrogen, oxygen, etc.). The fuel electrode 37, the air electrode 38, and the solid polymer electrolyte membrane 39 overlap in the thickness direction and are integrated to form a membrane/electrode assembly (MEA), and the membrane/electrode assembly 42 is connected to the separator 40. , 41 are sandwiched in. The solid polymer electrolyte membrane 39 has proton conductivity and no electronic conductivity.

A gas diffusion layer 43 is formed between the fuel electrode 37 and the separator 40, and a gas diffusion layer 44 is formed between the air electrode 38 and the separator 41. Gas seals 45 are installed between the fuel electrode 37 and the separator 40 and above and below the gas diffusion layer 43. Gas seals 46 are installed between the air electrode 38 and the separator 41 and above and below the gas diffusion layer 44 .

In the polymer electrolyte fuel cell 36, hydrogen (fuel) is supplied to the fuel electrode 37 (cathode 12), and air (oxygen) is supplied to the air electrode 38 (anode 11). At the fuel electrode 37, hydrogen is decomposed into protons (hydrogen ions, H ⁺ ) and electrons by a reaction (catalytic action) of H ₂ →2H ⁺ +2e ⁻ . Thereafter, protons pass through the solid polymer electrolyte membrane 39 and move from the fuel electrode 37 to the air electrode 38, and electrons pass through the conductive wire 47 and move to the air electrode 38. Protons generated at the fuel electrode 37 flow through the solid polymer electrolyte membrane 39 . At the air electrode 38, protons transferred from the solid polymer electrolyte membrane 39 and electrons transferred through the conducting wire 47 react with oxygen in the air, and water is generated by the reaction 4H ⁺ +O ₂ +4e→2H ₂ O.

The polymer electrolyte fuel cell 36 has a fuel electrode 37 (cathode 12) and an air electrode 38 (anode 12) made of platinum group metal fine powder 37 (particle size: 50 nm to 50 nm) obtained by finely pulverizing Pt31 (platinum) (platinum group metal). 80 nm), and further, the Fe content (weight ratio) in Fe-Ni permalloy 50 is adjusted so that the work function of permalloy fine powder 52 obtained by finely pulverizing Fe-Ni permalloy 50 approximates the work function of platinum group elements. Since the content rate (weight ratio) of Ni and Ni have been determined, the fuel electrode 37 and the air electrode 38 have approximately the same work function as the electrode supporting a platinum group element (platinum). It shows almost the same excellent catalytic activity (catalytic action) as an electrode supporting hydrogen, and hydrogen is efficiently decomposed into protons and electrons.

In the electromotive voltage test, the voltage (V) between the electrode (fuel electrode 37 or air electrode 38) and the electrode (fuel electrode 37 or air electrode 38) is measured for 15 minutes after hydrogen gas is injected. was measured. In the diagram showing the results of the electromotive voltage test in Figure 7, the horizontal axis represents the measurement time (min), and the vertical axis represents the time between the electrodes (fuel electrode 37 and air electrode 38) and the electrodes (fuel electrode 37 and air electrode 38). represents the voltage (V) between the electrodes. In the polymer electrolyte fuel cell 36 using a fuel electrode 37 (cathode 12) and an air electrode 38 (anode 11), the voltage between the electrodes is 1.07 (V) to 1.088 (V) as shown in FIG. V).

In the IV characteristic test, a load 48 is connected between the electrodes (fuel electrode 37 and air electrode 38) and the electrodes (fuel electrode 37 and air electrode 38) (between the electrodes), and the relationship between voltage and current is measured. did. In the diagram showing the results of the IV characteristic test in FIG. 8, the horizontal axis represents current (A), and the vertical axis represents voltage (V). In the polymer electrolyte fuel cell 36 using the fuel electrode 37 (cathode 12) and the air electrode 38 (anode 11), a gradual voltage drop was observed as shown in FIG. As shown in the results of the electromotive voltage test in FIG. 7 and the results of the IV characteristic test in FIG. It was confirmed that it has an excellent catalytic action that promotes oxidation, as well as an excellent oxygen reduction function (catalytic action).

FIG. 9 is a diagram illustrating a method of manufacturing the anode 11 (air electrode 38) and cathode 12 (fuel electrode 37) used in the electrolyzer 10 and the polymer electrolyte fuel cell 36. The anode 11 (air electrode 38) and the cathode 12 (fuel electrode 37) are formed, as shown in FIG. It is manufactured by an electrode manufacturing method having steps S4 and S5 of forming a thin plate-like foamed metal electrode. In the electrode manufacturing method, an anode 11 (air electrode 38) and a cathode 12 (fuel electrode 37) are manufactured using platinum group metal 49 and Fe--Ni permalloy 50 as raw materials. It is assumed that platinum 49 (Pt) is used as the platinum group metal 49.

In the content determination step S1, the content of Fe (iron) in the Fe-Ni permalloy 50 is determined so that the work function of the permalloy fine powder 52 obtained by pulverizing the Fe-Ni permalloy 50 approximates the work function of platinum group elements. The content rate of Ni (nickel) is determined. The content of Fe in Fe-Ni permalloy 50 is determined in the range of 45% to 55%, preferably in the range of 49% to 51%, and the content of Ni in Fe-Ni permalloy 50 is determined in the range of 45% to 55%. %, preferably in the range of 49% to 51%.

In the fine powder creation step S2, at least one type of platinum group metal 49 (platinum 49) selected from various platinum group metals is finely pulverized to create a platinum group metal fine powder 51, and in the content rate determination step S1. Fe--Ni permalloy 50 formed from Fe and Ni at the determined content is pulverized to produce permalloy fine powder 52. Platinum 49 (Pt) is pulverized to a particle size of 50 nm to 80 nm using a pulverizer to produce platinum group metal fine powder 51 with a particle size of 50 nm to 80 nm, and Fe-Ni permalloy 50 is pulverized to a particle size of 1 μm to 100 μm using a pulverizer. permalloy fine powder 51 having a particle size of 1 μm to 100 μm, preferably 30 μm to 60 μm.

The electrode manufacturing method involves finely pulverizing Fe-Ni permalloy 50 to a particle size of 1 μm to 100 μm, preferably 30 μm to 60 μm, to form a porous structure having a large number of fine continuous pores 23 (continuous ventilation pores). A thin plate-like foamed metal electrode 24 with a microporous structure and a large specific surface area can be created by molding the electrode into a microporous structure. The anode 11 (air electrode 38) and the cathode 12 (fuel pole 37) can be made.

In the fine powder mixture creation step S3, a predetermined binder 53 and a predetermined pore forming material 54 are added to the platinum group metal fine powder 51 and the permalloy fine powder 52 created in the fine powder mixture creation step S2, and the platinum group metal fine powder 51 and the permalloy fine powder are added. A binder 53 and a pore-forming material 54 are uniformly mixed and dispersed in a fine powder 52 to form a fine powder mixture 55. In the fine powder mixture 55 made in the fine powder mixture creation step S3, the proportion of the platinum group metal fine powder 51 relative to the total weight (100%) of the fine powder mixture 55 in which the platinum group metal fine powder 51 and the permalloy fine powder 52 are mixed is A fine powder in which a platinum group metal fine powder 51 and a permalloy fine powder 52 are mixed, with a weight ratio (content) determined in a range of 4% by weight to 10% by weight, preferably in a range of 5% by weight to 8% by weight. The weight ratio (content) of the permalloy fine powder 52 to the total weight (100%) of the mixture 55 is determined in the range of 90% to 96% by weight, preferably in the range of 92% to 95% by weight. In the electrode manufacturing method, since the weight ratio of the platinum group metal fine powder 51 to the total weight of the fine powder mixture 55, which is a mixture of the platinum group metal fine powder 51 and the permalloy fine powder 52, is within the above range, the expensive platinum group metal 49 is used. (Platinum 49) content is low, and the anode 11 (air electrode 38) and cathode 12 (fuel electrode 37) can be made at low cost.

In the fine powder mixture creation step S3, a platinum group metal fine powder 51 of platinum 49 (Pt) with a determined weight ratio, a permalloy fine powder 52 of Fe-Ni permalloy 50 with a determined weight ratio, and a binder 53 (powdered resin-based A platinum group metal fine powder 51 of platinum 49, a permalloy fine powder 52 of Fe-Ni permalloy 50, and a binder 53 are stirred and mixed by the mixer or stirrer, and the platinum group metal fine powder is mixed. A fine powder mixture 55 (foamed metal forming material) is prepared in which the body 51, permalloy fine powder 52, and binder 53 are uniformly mixed and dispersed. Next, a predetermined amount of pore-forming material 54 (powder foaming agent) is mixed (added) to the fine powder mixture 55 . A predetermined amount of pore-forming material 54 is put into a mixer or stirrer, and a fine powder mixture 55 (metal foam molding material) is made by uniformly mixing and dispersing the pore-forming material 54 in the fine powder mixture 55 using the mixer or stirrer. . The average diameter and porosity of the continuous pores 25 formed in the anode 11 (air electrode 38) and cathode 12 (fuel electrode 37) are determined by the amount of the pore-forming material 54 (powder foaming agent) mixed (added amount).

In the fine powder mixture molded product creation step S4, the fine powder mixture 55 (metal foam molding material) created in the fine powder mixture creation step S3 is put into an injection molding machine (not shown) or an extrusion molding machine (not shown). Then, the fine powder mixture 55 is injection molded with an injection molding machine, or the fine powder mixture 55 is extruded with an extrusion molding machine, and the fine powder mixture 55 is formed into a thin plate shape with a predetermined area (thickness dimension L1 is 0.05 mm to 0.05 mm). A fine powder mixture molded article 56 (foamed metal molded article) is made into a fine powder mixture molded article (within a range of .5 mm).

In the thin plate-like foamed metal electrode production step S5, the fine powder mixture molded product 56 (foamed metal molded product) made by injection molding or extrusion molding in the fine powder mixture molded product creation step S4 is degreased, and the degreased fine powder mixed molding is performed. The product 56 is placed in a firing furnace (combustion furnace, electric furnace, etc.), and the fine powder mixture molded product 56 is sintered (fired) at a predetermined temperature for a predetermined period of time in the kiln. ) are evenly formed and the platinum group metal fine powder 51 is fixed to the permalloy melt of the fused permalloy fine powder 52, and the platinum group metal fine powder 51 is fixed to the permalloy melt that defines and surrounds the open cells 23. A thin plate-like foamed metal electrode 24 (having a thickness L1 of 0.05 mm to 0.5 mm) and an anode 11 (air electrode 38) and a cathode 12 (fuel electrode 37) having a microporous structure where the metal fine powder 51 is exposed are made.

The sintering (firing) temperature is 900°C to 1400°C. The sintering (firing) time is 2 to 6 hours. In the thin plate-like foamed metal electrode production step S5, when the fine powder mixture molded product 56 (foamed metal molded product) formed into a thin plate shape with a predetermined area is sintered, the pore forming material 54 ( After foaming of the powder foaming agent), the pore-forming material 54 disappears from inside the fine powder mixture molded product 56, resulting in a thin plate-like microporous structure in which many fine continuous pores 23 (continuous vents) are formed. Foamed metal electrodes 24 (anode 11 (air electrode 38) and cathode 12 (fuel electrode 37) having a thickness L1 of 0.05 mm to 0.5 mm are manufactured.

In the electrode manufacturing method, a platinum group metal fine powder 51 of platinum group metal 49 (platinum 49) and a permalloy fine powder 52 of Fe-Ni permalloy 50 are connected via a binder 53 by injection molding or extrusion molding. After degreasing the fine powder mixture molded product 56 (foamed metal molded product) made by extrusion molding, it is sintered (fired) at a predetermined temperature to form a micro-particle having a large number of fine continuous pores 23 (continuous ventilation pores). The thin plate-like foamed metal electrode 24 (anode 11 (air electrode 38) and cathode 12 (fuel electrode 37) with a thickness L1 of 0.05 mm to 0.5 mm) having a porous structure can be made and has high strength. It is possible to create an anode 11 (air electrode 38) and a cathode 12 (fuel electrode 37) containing a small amount of platinum group metal, which can maintain their shape and prevent breakage or damage when subjected to impact. can. The electrode manufacturing method can produce the anode 11 (air electrode 38) and cathode 12 (fuel electrode 37) with a thickness in the range of 0.05 mm to 0.5 mm, so the electrical resistance is low and current can flow smoothly. The anode 11 (air electrode 38) and cathode 12 (fuel electrode 37) that are capable of proton conductivity can be made.

In the electrode manufacturing method, the content of Fe (iron) in Fe-Ni permalloy 50 and Ni ( a content rate determination step S1 of determining the content rate of nickel), and finely pulverizing at least one type of platinum group metal 49 (platinum 49) selected from various platinum group metals to form a platinum group metal fine powder 51. (Platinum group metal fine powder 51 of platinum 49) is made, and Fe-Ni permalloy 50 formed from Fe and Ni at the content determined in the content rate determination step is pulverized to produce permalloy fine powder 52. A predetermined binder 53 and a predetermined pore-forming material 54 are added to the platinum group metal fine powder 51 and permalloy fine powder 52 created in step S2 and the fine powder creation step S2, and the platinum group metal fine powder 51 and permalloy fine powder 52 are added. A fine powder mixture creation step S3 in which a binder 53 and a pore forming material 54 are uniformly mixed and dispersed to create a fine powder mixture 55 (foamed metal molding material), and a fine powder mixture 55 created in the fine powder mixture creation step S3. A fine powder mixture molded product creation step S4 in which a fine powder mixed molded product 56 (foamed metal molding material) is produced by molding into a thin plate shape (extrusion molding or injection molding), and a fine powder created by the fine powder mixed molded product creation step S4. The mixed molded product 56 is degreased and the fine powder mixed molded product 56 is sintered at a predetermined temperature, so that a large number of fine continuous pores 23 are uniformly formed, and platinum group metal is added to the permalloy melt of the fused permalloy fine powder 52. Thin plate foaming to create a thin plate foam metal electrode 24 with a microporous structure in which the metal fine powder 51 is fixed and the platinum group metal fine powder 51 is exposed on the surface of the permalloy melt that defines and surrounds the open cells 23. Since the anode 11 (air electrode 38) and cathode 12 (fuel electrode 37) are manufactured through each process including the metal electrode production process S5, the thickness L1 is within the range of 0.05 mm to 0.5 mm through these processes S1 to S5. The anode 11 (air electrode 38) and the cathode 12 (fuel electrode 37) (microporous structure thin plate-shaped foamed metal electrode 24) can be manufactured in which a large number of fine continuous pores 23 (continuous ventilation holes) are formed. The anode 11 (air electrode 38) and cathode 12 (fuel electrode 37) can be manufactured at low cost.

The electrode manufacturing method can exhibit excellent catalytic activity (catalytic action) that is almost the same as an electrode supporting a platinum group element (platinum), and also has excellent catalytic activity (catalytic action) and has a catalytic function. An anode 11 (air electrode 38) and a cathode 12 containing a small amount of platinum group metal, which can be fully and reliably utilized and suitably used in the electrolyzer 10 and the polymer electrolyte fuel cell 36. (Fuel electrode 37) can be made. In the electrode manufacturing method, the anode 11 and cathode 12 produced by the method exhibit excellent catalytic activity (catalytic action) that is almost the same as an electrode supporting a platinum group element, so that electrolysis can be carried out efficiently in the electrolyzer 10. It is possible to produce an anode 11 and a cathode 12 containing a small amount of platinum group metal, which can generate a large amount of hydrogen gas in a short period of time.

10 Electrolyzer 11 Anode (electrode)
12 Cathode (electrode)
13 Solid polymer electrolyte membrane 14 Anode power supply member 15 Cathode power supply member 16 Anode water tank 17 Cathode water tank 18 Anode main electrode 19 Cathode main electrode 20 Membrane/electrode assembly 21 Front face 22 Back face 23 Continuous pores (continuous ventilation holes)
24 Thin plate-shaped foamed metal electrode with microporous structure 25 Communication port 26 Outer periphery 27 Hydrogen gas generation system 28 DC power supply 29 Water storage tank 30 Water supply pump 31 Oxygen gas-liquid separator 32 Circulation pump 33 Circulation pump 34 Hydrogen gas-liquid separator 35 Cylinder 36 Polymer electrolyte fuel cell 37 Fuel electrode 38 Air electrode 39 Solid polymer electrolyte membrane 40 Separator 41 Separator 42 Membrane/electrode assembly 43 Gas diffusion layer 44 Gas diffusion layer 45 Gas seal 46 Gas seal 47 Conductor 48 Load 49 Platinum Group metals (platinum)
50 Fe-Ni permalloy 51 Platinum group metal fine powder 52 Permalloy fine powder 53 Binder 54 Pore forming material (foaming agent)
55 Fine powder mixture 56 Fine powder mixture molded product (foamed metal molded product)
L1 Thickness dimension S1 Content rate determination process S2 Fine powder creation process S3 Fine powder mixture creation process S4 Fine powder mixture molded product creation process S5 Thin plate foam metal electrode creation process

Claims (6)

A method for producing the anode and the cathode of an electrolyzer for chemically decomposing a predetermined aqueous solution, comprising an anode, a cathode, and an electrode assembly membrane located between the anode and the cathode to connect the electrodes. ,
The method for producing the anode and the cathode includes a method in which Fe (iron) is added to the total weight of the permalloy fine powder so that the work function of the permalloy fine powder obtained by finely pulverizing Fe-Ni permalloy approximates the work function of a platinum group element. a content rate determination step of determining the content rate in the range of 45% to 55%, and determining the content rate of Ni (nickel) to the total weight of the permalloy fine powder in the range of 45% to 55%;
Platinum is finely pulverized to produce platinum group metal fine powder with a particle size of 50 nm to 80 nm, and Fe--Ni permalloy formed from Fe and Ni with a content determined in the content rate determination step is pulverized to obtain a particle size of 50 nm to 80 nm. a fine powder creation step of making the permalloy fine powder with a diameter of 1 μm to 100 μm;
The weight ratio (content) of the platinum group metal fine powder to the total weight (100%) of the mixture of the platinum group metal fine powder and the permalloy fine powder created by the fine powder creation step is 4% by weight to 10% by weight. The weight ratio (content) of the permalloy fine powder to the total weight (100%) of the mixture is determined to be in the range of 90% to 96% by weight, and the platinum group metal fine powder in the above weight ratio A predetermined binder and a predetermined pore-forming material are added to Permalloy fine powder having the same weight ratio as above, and the binder and the pore-forming material are uniformly mixed and dispersed in the platinum group metal fine powder and the Permalloy fine powder. a step of creating a fine powder mixture to create a body mixture;
The fine powder mixture produced by the fine powder mixture creation step is put into an injection molding machine or an extrusion molding machine, and the fine powder mixture is injection molded by the injection molding machine, or the fine powder mixture is extruded by the extrusion molding machine. A step of creating a fine powder mixture molded article by molding the fine powder mixture into a thin plate shape with a predetermined area and a thickness of 0.05 mm to 0.5 mm;
The fine powder mixed molded product produced by injection molding or extrusion molding in the fine powder mixed molded product creation step is degreased, the degreased fine powder mixed molded product is put into a firing furnace, and the fine powder mixed molded product is At the time of sintering the fine powder mixture molded product which is sintered at a temperature of 900° C. to 1400° C. for 2 to 6 hours in a firing furnace and formed into a thin plate shape of a predetermined area, inside the fine powder mixed molded product. After the pore-forming material foams, the pore-forming material disappears from the inside of the fine powder mixture molded product, and the anode is a thin plate-like foamed metal electrode with a microporous structure in which a large number of fine continuous pores are formed. A method for manufacturing the anode and the cathode, comprising the step of creating a thin plate-like foamed metal electrode for making the cathode. The open cells formed in the anode and the cathode extend irregularly in the thickness direction between the front and rear surfaces of the anode and the cathode, and extend between the center and the outer periphery of the anode and the cathode. The method for manufacturing the anode and the cathode according to claim 1, wherein the anode and the cathode extend in a radial direction while being irregularly bent . The open cells that are adjacent in the radial direction and extend in a bent direction in the thickness direction are partially connected in the radial direction so that one open cell and the other open cell are in communication with each other, and the open cells are adjacent in the thickness direction. The continuous cells bend and extend in the radial direction, and are partially connected in the thickness direction, so that one continuous cell and the other continuous cell communicate with each other, and the average diameter of the continuous cells extends in the thickness direction. According to claim 2, the thickness is not uniform in the thickness direction and changes irregularly in the thickness direction, and the thickness is not uniform in the radial direction but changes irregularly in the radial direction. The method for manufacturing the anode and cathode described above . The anode and the cathode according to claim 3, wherein the average diameter of continuous pores formed in the anode and the cathode is in the range of 1 μm to 100 μm and varies in the range of ±0.1 μm to ±5 μm. manufacturing method . The method for manufacturing the anode and the cathode according to any one of claims 1 to 4 , wherein the open cells formed in the anode and the cathode have a porosity in the range of 45% to 55% . The method for manufacturing the anode and the cathode according to any one of claims 1 to 5, wherein the anode and the cathode have a density in a range of 6.0 g/cm ² to 8.0 g/cm ² .

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