JP2007245122A - Hydrogen permeable membrane of composite multi-layer structure and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive hydrogen permeable membrane of a composite multi-layer structure having no pin hole even if it is rolled to a thin shape, having a sufficient permeation/separation performance of hydrogen of a high purity and not causing hydrogen brittleness. <P>SOLUTION: The hydrogen permeable membrane 21 of the composite multi-layer structure has a composite core superposed body 51 in which a first metal layer comprising a base metal with a high hydrogen permeable performance, i.e., a transition metal of a high melting point having a body-centered cubic structure and a second metal layer, i.e., a transition metal hardly creating a metal hydride are alternately superposed, and the uppermost and lowermost layer 50 are the second metal layers. Catalyst metal layers 52 comprising Pd or its alloy are formed on both surfaces of the composite core superposed body 51. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is a composite in which a hydrocarbon such as methane gas and steam are mixed and reformed at high temperature, and then only hydrogen gas is permeated and separated from the generated mixed gas to produce high purity hydrogen gas. The present invention relates to a hydrogen permeable membrane having a multilayer structure and a manufacturing method thereof.

  Conventionally, this type of composite multilayer structure hydrogen permeable membrane is known as a single layer using Pd or an alloy containing Pd that selectively transmits only hydrogen. In some cases, a Pd alloy film is formed on the surface of the ceramic porous support by a plating method (see Patent Document 1).

  In addition, as a composite multilayer structure hydrogen permeable film having a sandwich structure, there is a film in which a Pd film or a Pd alloy film is arranged on both surfaces of a metal film having high hydrogen permeability (see Patent Document 2).

  First, a hydrogen separation method using Pd or Pd alloy as a hydrogen permeable membrane will be briefly described.

  Normally, a hydrogen permeable membrane having a composite multilayer structure is used by rolling Pd or a Pd alloy into a thin film. For example, a cylindrical tube is made of a Pd film or a Pd alloy film, one end of the tube is sealed and welded, hydrogen gas in a pressurized state is supplied to the outside of the tube, and heated to a certain temperature. Molecules dissociate atomically, form a solid solution with Pd, and are taken into the Pd film.

  The incorporated hydrogen atoms diffuse from the outside of the high pressure tube to the low inside due to the difference in hydrogen partial pressure inside and outside the tube, and become hydrogen molecules again on the inside surface. Impurities other than hydrogen contained in the reformed gas produced from methane or methanol by steam reforming do not react with Pd, and therefore remain outside the tube, thereby purifying hydrogen.

  In a hydrogen permeable membrane having a composite multilayer structure of only Pd, deterioration due to hydrogen embrittlement is a problem, and it is used after being alloyed. Already, Pd alloys with 23% silver and 40% copper are well known, and hydrogen purifiers using a single tube made of only a Pd alloy film have been put into practical use. However, the thickness of the tube used is as thick as 80 μm or more in order to maintain the strength, and there is a problem that the amount of hydrogen permeation is small and expensive.

  FIG. 8 shows an example of a conventional hydrogen permeable membrane having a composite multilayer structure described in Patent Document 1. As shown in FIG. As shown in FIG. 8, the hydrogen separator 1 has a porous substrate 2 made of a cylindrical ceramic and a surface 2a of the porous substrate that becomes a surface to be processed outside thereof, and has a hydrogen separating ability such as Pd and Pd. And a hydrogen separation membrane 4 formed by electroless plating, and the diameter of the small holes 5 of the porous substrate 2 is not more than the thickness of the hydrogen separation membrane 4 and not less than 1 μm.

  Here, the operation of the cylindrical hydrogen separator 1 in which the hydrogen separation membrane 4 forms the outer surface will be described.

  First, when pressurized hydrogen gas is supplied to the outside of the cylindrical hydrogen separator 1 and heated to a certain temperature, the hydrogen molecules in contact with the hydrogen separation membrane 4 on the surface of the porous body 2 become atomic. It dissociates, forms a solid solution with Pd, and is taken into the Pd membrane, that is, into the hydrogen separation membrane 4.

  The taken-in hydrogen atoms diffuse from the outer side of the hydrogen separation membrane 4 having a high pressure to the lower side due to the difference in hydrogen partial pressure inside and outside the hydrogen separation membrane 4, and become hydrogen molecules again on the inner surface. After that, it flows in the small holes 5 of the cylindrical porous substrate 2 from the surface 2a of the porous body. Since many impurities contained in the reformed hydrogen gas do not react with Pd, they remain outside the hydrogen separator 1, thereby purifying the hydrogen.

  However, the conventional method of forming a Pd film or Pd alloy film on the outer surface of a porous substrate made of ceramic by plating can increase the mechanical strength of the structure, and is a thin film of about 1 to 5 μm and a certain amount Even if the pore size of the porous support is selected so as not to affect the permeation amount, the plating thickness varies in the plating process and the Pd alloy film becomes thin. It is difficult to eliminate the leakage of the pinhole.

  Therefore, if there is an impurity in the reformed hydrogen gas generated as a result of the steam reforming, the purity of the hydrogen gas obtained through permeation through the film also deteriorates in proportion to the impurity concentration. For example, the thickness of the Pd alloy film At 5 μm, the purity was about 99.9%, and carbon monoxide of 50 ppm or more was mixed, so that the permeated gas could not be used by supplying it to a solid polymer membrane fuel cell. In addition, when used for a long time, the strength decreases due to hydrogen embrittlement, and in particular, there is a problem that deterioration of the pinhole portion is promoted and breakage easily occurs.

  FIG. 9 shows a conventional hydrogen permeable membrane described in Patent Document 2. As shown in FIG. 9, the hydrogen permeable film 6 is composed of a metal film 7 having a high hydrogen permeable performance and a Pd film or a Pd alloy film 8 disposed on both sides thereof.

  The hydrogen permeable membrane 6 having the sandwich structure is produced in the following forms (1) and (2).

  (1) The metal film 7 having high hydrogen permeation performance and the Pd film or the Pd alloy film 8 are dry-etched in vacuum to remove impurities and oxide layers on the surface. Etching can be performed by ion bombardment with inert gas ions. Thereafter, a Pd film or a Pd film is disposed on both surfaces of the metal film 7 having high hydrogen permeation performance while maintaining a vacuum, and is rolled in a vacuum.

  (2) The Pd film or the Pd alloy film 8 is disposed on both surfaces of the metal film 7 having high hydrogen permeation performance and heated in vacuum to remove impurities and oxide layers. A technique such as hot pressing can be applied to heating in vacuum. Then roll.

  An attachment method and operation of the hydrogen permeable membrane having the sandwich structure thus prepared will be described.

  As shown in FIG. 10, a cylindrical tube is usually formed by winding a hydrogen permeable membrane 6 around an outer layer 10 of a cylindrical porous body 9 and welding a mating portion 11 with a copper braze 12. Next, one end of the tube is hermetically welded, and pressurized raw material hydrogen gas is supplied to the outside of the tube.

  When heated to a certain temperature, the hydrogen molecules in contact with the tube surface dissociate into atoms, form a solid solution with Pd, and are taken into the Pd film. Due to the difference in hydrogen partial pressure between the inside and outside of the tube, the incorporated hydrogen atoms quickly diffuse from the outside of the tube with high hydrogen partial pressure through the metal film with high hydrogen permeability to the inside with low hydrogen partial pressure. It becomes hydrogen molecule again. Many impurities contained in the reformed hydrogen gas do not react with Pd and remain outside the tube, thereby purifying the hydrogen.

  In the hydrogen permeable membrane 6 having the sandwich structure formed in this way, the metal 7 having a high hydrogen diffusion coefficient and high hydrogen permeation performance is used for the core material. A product with high transmission performance is obtained.

  In addition, since a Pd film or alloy film is arranged on both sides of a metal film having high hydrogen permeation performance, an oxide film layer is not formed on the surface, and since it has a laminated structure, it is a dense composite multilayer having no pinholes. A hydrogen permeable membrane having a composite multilayer structure is obtained, and further, a Pd film or a Pd alloy film is uniformly arranged on both sides of a metal film having high hydrogen permeability, which is considered to be particularly weak in hydrogen embrittlement. Deterioration of physical properties due to is reduced.

  However, in a hydrogen permeable membrane in which a Pd (palladium) coating layer is formed on both surfaces of a V (vanadium) base layer as in Patent Document 2, interdiffusion between V and Pd proceeds under practical temperature conditions, and V is the surface. The catalyst layer moves to Pd, and further precipitates on the outer surface of Pd, and easily oxidizes V to form an oxide film, which loses the catalytic ability to atomize and dissociate hydrogen molecules, resulting in hydrogen permeation performance. There was a problem of being lowered.

As a method for solving the above problem, Patent Document 3 discloses a hydrogen permeable membrane in which a SiO ₂ intermediate layer is interposed between a V base layer and a Pd coating layer.

Further, in Patent Document 4, a metal base layer containing a VA group element and at least one of two surfaces of the metal base layer are selected and selected from Ni (nickel) and Co (cobalt). Disclosed is a hydrogen permeable membrane comprising a metal intermediate layer containing an element and a metal coating layer containing Pd (palladium) formed on a surface of the metal intermediate layer on which no metal base layer is formed. Has been.
JP 2000-317282 A JP-A-11-276866 JP-A-7-185277 JP 2003-112020 A

However, in the hydrogen permeable membrane in which the SiO ₂ intermediate layer is interposed between the V base layer and the Pd coating layer as shown in Patent Document 3 above, the diffusion between V and Pd can be reduced. However, a ceramic intermediate layer such as SiO ₂ has a problem of low hydrogen permeation performance.

  This is because the ceramic intermediate layer allows only hydrogen in the molecular state to pass through. Since hydrogen needs to be recombined once before passing through the ceramic intermediate layer and then dissociated again after passing through the ceramic intermediate layer, hydrogen is required. Transmission performance is low. Furthermore, when ceramic and metal are joined, there are problems that the production is relatively difficult and the hydrogen permeable membrane is easily cracked due to the difference in thermal expansion coefficient.

  Patent Document 4 is selected from Ni (nickel) and Co (cobalt) formed on at least one of two surfaces of a metal base layer containing a VA group element and the metal base layer. A metal intermediate layer containing an element and a metal coating layer containing Pd (palladium), which is formed on a surface of the two metal intermediate layers on which the metal base layer is not formed, selectively transmits hydrogen. Although it is a hydrogen permeable membrane, it has better adhesion and better hydrogen permeation performance than the previous ceramic intermediate layer, and the interdiffusion is reduced and deterioration of hydrogen permeation performance can be suppressed.

  However, when a nickel or cobalt intermediate layer having a low hydrogen solubility even though the diffusion coefficient is large is formed on the permeable membrane, there is a problem that the hydrogen permeation performance in that portion is extremely lowered. In addition, the metal serving as the metal base layer containing the VA group element has a problem in that physical properties deteriorate due to hydrogen embrittlement because hydride is formed through the presence of hydrogen and volume expansion is repeated.

  The present invention solves the above-described conventional problems, and there is no pinhole that permeates and separates only hydrogen gas from a mixed gas after methane gas or the like is subjected to steam reforming treatment to produce high-purity hydrogen gas, An object of the present invention is to provide an inexpensive composite multilayer structure hydrogen permeable membrane having good hydrogen permeation separation performance and not hydrogen embrittlement, and a method for producing the same.

  In order to achieve the above object, a hydrogen permeable membrane having a composite multilayer structure according to the present invention includes a first metal layer made of a base metal having high hydrogen permeable performance, and a second metal layer made of a modified metal that hardly forms a metal hydride. Have a composite core laminate in which the uppermost lower layer is the second metal layer, and a catalyst metal layer made of Pd or Pd alloy is formed on both surfaces of the composite core laminate. It has a composite multilayer structure.

  As a result, a second metal layer is formed between the first metal layer of the base metal and the catalytic metal layer of Pd, which is easily diffused with the base metal and difficult to diffuse with Pd. In addition, the first metal layer and the second metal layer become a multilayer laminate that is alternately laminated by repetition of diffusion bonding and rolling by laminating a plurality of layers. Since the base metal, which is the metal layer, is structurally divided in an extremely thin film state, distortion due to volume expansion is reduced, and deterioration of physical properties due to hydrogen embrittlement is suppressed.

  Also, expensive Pd is only used on both surfaces of the composite multilayer structure hydrogen permeable membrane, resulting in a thin and inexpensive hydrogen permeable membrane free of pinholes.

  A hydrogen permeable membrane having a composite multilayer structure and a method for producing the same according to the present invention include a second metal layer that is easily diffused between a base metal and a Pd catalyst metal layer and a base metal first metal layer, and hardly diffuses from Pd. Is formed, the interdiffusion between the first metal layer and the catalytic metal layer is suppressed and the catalytic function of the surface layer is maintained, and the first metal layer and the second metal layer are alternately laminated by heat treatment. Due to diffusion bonding and rolling treatment, hydrogen embrittlement is suppressed by the solid solution of the first metal layer and the second metal layer and the ultrathin film stacking effect. Therefore, it is possible to provide a membrane having a high permeation separation performance and a high-performance hydrogen permeation amount.

  In the invention of the hydrogen permeable membrane having a composite multilayer structure according to claim 1, the first metal layer made of a base metal having high hydrogen permeable performance and the second metal layer which is a modified metal which is difficult to form a metal hydride are alternately formed. The composite core laminate is formed by laminating a catalyst metal layer made of Pd or a Pd alloy on both sides of the composite core laminate, and the first metal layer and the second metal layer are When diffusion bonding and rolling are performed in a multilayered state in which the layers are alternately stacked, hydrogen embrittlement is suppressed by the solid solution of the second metal layer in the first metal layer and the effect of ultrathin film stacking. However, there is no pinhole, the permeation separation performance of high-purity hydrogen is good, and high-performance hydrogen permeation can be maintained.

  In the invention of the hydrogen permeable membrane having a composite multilayer structure according to claim 2, the first metal layer made of a base metal having high hydrogen permeability and the second metal layer which is a modified metal which is difficult to form a metal hydride are alternately formed. It has a composite core laminate in which the uppermost lower layer is the second metal layer, and a catalyst metal layer made of Pd or Pd alloy is formed on both sides of the composite core laminate, A second metal layer that is hard to diffuse with the Pd catalyst metal layer is formed on the uppermost layer, and mutual diffusion between the first metal layer and the catalyst metal layer is suppressed, and the catalytic function of the surface layer is stably maintained. The base metal layer is prevented from being deposited on the surface of the catalyst metal layer, and long-term reliability is ensured.

  In the invention of the hydrogen permeable membrane having the composite multilayer structure according to claim 3, the base metal having high hydrogen permeability of the first metal layer according to claim 1 or 2 is a high melting point material having a body-centered cubic structure. A VA group metal of transition metal or an alloy thereof, and a VA group metal having a body-centered cubic structure is a metal having a high hydrogen diffusion coefficient and a relatively high hydrogen permeation performance. The performance can be ensured, the area of the hydrogen permeable membrane having a composite multilayer structure necessary for the hydrogen generator can be handled with a small area, and the size of the apparatus itself can be made compact.

  The invention of the hydrogen permeable membrane having a composite multilayer structure according to claim 4 is characterized in that the base metal having a high hydrogen permeability of the first metal layer according to any one of claims 1 to 3 is a body-centered cubic structure. It is one of Ta, Nb, V, Ta alloy, Nb alloy, and V alloy, which is a transition metal having a high melting point, and Ta, Nb, and V have not only a high hydrogen diffusion coefficient but also hydrogen solid solution. It is a metal that is particularly excellent in hydrogen permeation performance and can improve the performance as a hydrogen permeable membrane with a composite multilayer structure. When applied to a hydrogen generator, it can be used in a smaller area and the device itself Can be made more compact.

  The invention of the hydrogen permeable membrane having a composite multilayer structure according to claim 5 is characterized in that the second metal layer, which is a modified metal that hardly forms a metal hydride according to any one of claims 1 to 4, is Mo. , Re, Mo alloy, or Re alloy, and Mo and Re are metals that do not easily form metal hydrides. The function of suppressing the hydrogen embrittlement of the VA group metal and suppressing interdiffusion is remarkably exhibited.

  In the invention of the hydrogen permeable membrane having a composite multilayer structure according to claim 6, the composite core laminate in the invention according to any one of claims 1 to 5 is subjected to at least one diffusion bonding and rolling. As a result of repeated diffusion bonding and rolling, the solid solution of the modified metal into the first metal layer, which is the base metal, progresses to a metal layer with less hydrogen embrittlement, As the thickness of one layer becomes thinner, the structural breakage between metals proceeds, so that volume expansion in the metal hydride is suppressed and hydrogen embrittlement is reduced.

  The invention of the hydrogen permeable membrane having a composite multilayer structure according to claim 7 is characterized in that the total thickness of the composite core laminate in the invention according to any one of claims 1 to 6 is 1 to 200 μm and the first metal layer is The thickness of one sheet is 100 nm or less. When the total thickness is 200 μm or more, the hydrogen permeation performance is extremely deteriorated. The thinner the thickness is, the higher the hydrogen permeation performance is. Further, when the thickness of one metal layer is 100 nm or less, the structural breakage of the metal layer becomes remarkable, the volume expansion of the metal hydride is suppressed, and the deterioration of physical properties due to hydrogen embrittlement can be reduced.

  The invention of the hydrogen permeable membrane having a composite multilayer structure according to claim 8 is the invention according to any one of claims 1 to 7, wherein the thicknesses of the first metal layer and the second metal layer of the composite core laminate are as follows. If the ratio of the element is 0.05% to 10% in terms of the element ratio and the thickness ratio is 0.05% or less in terms of the element ratio, the effect of suppressing mutual diffusion The hydrogen permeation performance deteriorates at 10% or more.

  The invention of the method for producing a hydrogen permeable membrane having a composite multilayer structure according to claim 9 includes a first metal foil made of a base metal having high hydrogen permeability and a second metal foil that is a modified metal that is difficult to form a metal hydride. A lamination process in which a plurality of sheets are alternately laminated to form a laminated product, a diffusion bonding process in which the laminated product is diffusion-bonded by heat and pressure to form a diffusion-bonded product, and the diffusion-bonded product is rolled to a predetermined thickness and rolled to form a composite A rolling process for forming a core laminate, a repeated lamination rolling process for further repeating lamination and rolling of the composite core laminates as necessary to form a composite core laminate, and Pd or Pd alloy on both sides of the composite core laminate. A catalyst metal layer forming step for forming a catalyst metal foil, and the hydrogen permeation performance does not deteriorate over time due to interdiffusion under a heat load during practical use due to the presence of a modified metal, and the electrode foil film The structure of the laminate Hydrogen permeable membrane of the composite multilayer structure in which hydrogen embrittlement is suppressed can be easily manufactured by.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a schematic configuration diagram of a hydrogen generation / separation apparatus 22 incorporating a hydrogen permeable membrane 21 having a composite multilayer structure according to the first embodiment. FIG. 2 is a sectional view of the hydrogen permeable membrane 21 having the composite multilayer structure of the first embodiment. 3 is an enlarged cross-sectional view of a portion A of the hydrogen permeable membrane 21 having the composite multilayer structure according to the first embodiment. FIG. 4 is a schematic cross-sectional configuration diagram of a diffusion bonding apparatus 23 for diffusion bonding the metal foil body according to Embodiment 1 of the present invention. FIG. 5 is an enlarged sectional view showing the press member 73 of the diffusion bonding apparatus 23 according to the first embodiment of the present invention. FIG. 6 is a cross-sectional view of the rolling mill 20 according to Embodiment 1 of the present invention in the rolling process state. FIG. 7 is a manufacturing process diagram of the hydrogen permeable membrane 21 having the composite multilayer structure according to the first embodiment of the present invention.

  In FIG. 1, the hydrogen generation / separation apparatus 22 includes a reaction chamber 25 that generates a hydrogen mixed gas by reacting a hydrocarbon gas and water vapor at a high temperature of 300 ° C. or more and 1550 ° C. or less, and a mixture generated in the reaction chamber 25. It consists of a hydrogen permeable membrane 21 having a composite multilayer structure that transmits only hydrogen gas in the gas, and a separation chamber 26 that passes through the hydrogen permeable membrane 21 having a composite multilayer structure and is separated as a high-purity hydrogen gas. The reaction chamber 25 and the separation chamber 26 are configured to be divided into two independent chambers by a hydrogen permeable membrane 21 having a composite multilayer structure.

  The reaction chamber 25 is a rectangular reaction vessel 28 made of a stainless steel plate having a connection opening 27 at the top, and a flange 29 is formed on the entire periphery of the connection opening 27 so as to project outward.

  Further, the wall surface 30 of the reaction chamber 25 has a supply port 31 that communicates with the outside of the hydrogen generator / separator 22 and supplies fuel, and an exhaust port 32 that discharges the residual gas after the reforming process. The supply port 31 and the discharge port 32 are arranged as far as possible from each other, and a reforming catalyst 33 made of continuous nickel foam is inserted in the space between the supply port 31 and the discharge port 32 of the reaction chamber 25. A heating means 34 for heating the reaction chamber 25 is disposed below the reaction chamber 25.

  The separation chamber 26 includes a stainless steel separation container 36 having a connection opening 35 below, and a flange 37 projecting outward is formed around the connection opening 35 so as to correspond to the flange 29 of the reaction chamber 25. Is formed.

  The side surface of the outer shell 38 of the separation chamber 26 has an inlet 39 for introducing a sweep gas such as water vapor that communicates with the outside of the hydrogen generator / separator 22 and a discharge port 40 for discharging the generated hydrogen. Yes.

  The hydrogen permeable membrane 21 having a composite multilayer structure is located at the joint of the flange 37 of the separation chamber 26 and the flange 29 of the reaction chamber 25, and through a gasket 41 and a gasket 42 installed on the flange 29 and the flange 37, A plurality of bolts 43 and nuts 44 outside the flange 29 and the flange 37 are fastened and fixed.

  Further, in order to minimize the deformation of the hydrogen permeable membrane 21 having a composite multilayer structure that is attached so as to cover the connection opening 27 and the connection opening 35, the hydrogen permeable membrane 21, the flange 29, and the flange having the composite multilayer structure. A spacer 46 made of a stainless porous material is interposed so as to be supported by the protrusions 45 of 37.

  Further, the pressure in the reaction chamber 25 can be adjusted by installing a pressure adjusting valve 47 downstream of the discharge port 32 so that the pressure in the reaction chamber 25 is higher than that in the separation chamber 26.

  Note that the gasket 41 and the gasket 42 may be made of mild steel or copper metal, but considering the influence of damage to the hydrogen permeable membrane 21 having a composite multilayer structure, it is preferable to use more flexible graphite. As the gasket material used this time, highly purified graphite (Nippon Carbon Co., Ltd., Nika Film, FL-300SH) was used.

  As the porous stainless steel material used for the spacer 46, a mesh-like filter material made of SUS316 material was used.

  2 and 3, the hydrogen permeable membrane 21 having a composite multilayer structure includes a first metal layer 48 made of Ta (tantalum) as a base metal having high hydrogen permeable performance, and Mo ( Molybdenum) second metal layers 49 are alternately laminated, and the uppermost lower layer 50 has a composite core laminate 51 that becomes the second metal layer 49, and Pd is formed on both surfaces of the composite core laminate 51. Alternatively, it has a composite multilayer structure in which a catalytic metal layer 52 made of a Pd alloy is formed.

  The hydrogen permeable membrane 21 of this composite multilayer structure has a total thickness of 50 μm, and the Mo metal forming the second metal layer 49 has an element ratio of about 2% with respect to the Ta metal forming the first metal layer 48. Is set. The thickness distribution of each layer is such that the catalyst metal layer 52 is about 1 μm, and the remaining composite core laminate 51 is formed by forming about 10,000 layers each of a pair of the first metal layer 48 and the second metal layer 49. In other words, the thickness of one layer of the first metal layer 48 is calculated to be 5 nm or less.

  In the first embodiment, a VA group element Ta metal, which is a high melting point transition metal having a high hydrogen permeation performance and a body-centered cubic structure, is applied as the base metal to be the first metal layer 48. In addition, any of Nb, V, Ta alloy, Nb alloy, and V alloy may be adopted.

  In addition, although Mo is used as the modified metal of the second metal layer 49, Re (rhenium) or an alloy thereof may be used. Further, although the Pd catalytic metal layer 52 is provided on the outermost layer of the multilayer film, a Pd alloy layer may be provided instead of the Pd layer.

  In the first embodiment of the present invention, the thickness of the hydrogen permeable membrane 21 having a composite multilayer structure is 50 μm. However, when the thickness is 1 μm or less, the film does not have sufficient strength and cannot stand by itself, and when the thickness is 200 μm or more, the hydrogen permeation performance is extremely poor. Thus, the film area increases and the price increases, but the thickness is not limited to 50 μm.

  In the first embodiment of the present invention, the thickness of the first metal layer is designed to be 5 nm. However, when the thickness is 100 nm or less, the structural breakage of the metal layer becomes remarkable, and the effect of suppressing hydrogen embrittlement is obtained. The thickness of one metal layer is not limited to 5 nm.

  In the first embodiment of the present invention, the element ratio of the second metal layer 49 to the first metal layer 48 in the composite core laminate 51 is designed to be 2%. The brittle effect is not seen, and if it is 10% or more, the hydrogen permeation performance is extremely deteriorated, but it is not limited to 2%.

  Next, a method for manufacturing the hydrogen permeable membrane 21 having the composite multilayer structure according to the first embodiment of the present invention will be described with reference to FIGS.

  In FIG. 4, the diffusion bonding apparatus 23 includes a vacuum chamber 61, a high temperature diffusion furnace 62, and a hydraulic press 63.

  The vacuum chamber 61 is composed of a stainless upper chamber 64, a lower chamber 65, a vacuum pump 66 using an oil rotary pump and an oil diffusion pump as a vacuum exhaust system, and the upper chamber is removed by detaching the pin 68 of the connecting portion 67. 64 and the lower chamber 65 can be opened and closed up and down.

  The high-temperature diffusion furnace 62 is surrounded by a ceramic heat insulating wall 69 having a structure (not shown) that can be opened on the front surface, and a heater 70 made of Kanthal having high heat resistance is embedded therein. 71 can control the temperature in the high-temperature diffusion furnace 62.

  There is a lower stage 72 in the high-temperature diffusion furnace 62, and by installing a press member 73 on the lower stage 72, the upper stage 74 can be lowered by the hydraulic press 63 and pressure can be applied to the press member 73.

  The drive shaft 75 of the upper stage 74 passes through the heat insulating wall 69 and the upper chamber 64 and is connected to the hydraulic press 63. The intersection 76 between the drive shaft 75 and the upper chamber 64 is a drivable airtight mechanism using a bellows or the like. Thus, the inside of the vacuum chamber 61 and the outside are completely sealed.

  In FIG. 5, a press member 73 includes an upper pressurizing flat plate jig 77a and a lower pressurizing flat plate jig 77b obtained by cutting a SUS316L stainless steel plate to a certain size, and two support bolts 78a for fixing them in place. , 78b.

  Between the pressurizing flat plate jigs 77a and 77b, a first metal foil 79 made of Ta metal as a base metal having high hydrogen permeability and a second metal foil 80 made of modified metal Mo which is difficult to form a metal hydride, A laminated product 81 in which a plurality of sheets are laminated in an intersection is set. Further, there is no generation of gas due to heat between the both surfaces of the laminated product 81 and the pressurizing flat jigs 77a and 77b, and the elastic deformation is caused by the pressurization, and the surface of the laminated product 81 and the pressurizing flat jigs 77a and 77b. In this state, releasable sheets 82a and 82b having good releasability after diffusion bonding are interposed.

  As the material of the peelable sheets 82a and 82b, silica fiber non-woven fabric (Advantech Toyo Co., Ltd., silica fiber filter paper, QR-100) purified at a temperature of 1000 ° C. or higher, or graphite purified at about 2000 ° C. (Nippon Carbon Co., Ltd., Nika Film, FL-300SH) and carbon fiber felt (Nihon Carbon Co., Carboron, GF-20-2F) that has been highly purified at about 2000 ° C. can be used.

  In FIG. 6, the rolling mill 20 includes an upper roll 85 and a lower roll 86 that are rotated at a predetermined speed by a power source of a motor 84 of the machine unit 83, and an adjustment handle 87 that adjusts the interval between the upper and lower rolls 85 and 86. Therefore, the rolled material 88 is repeatedly rolled to reduce the thickness to a predetermined thickness while the interval between the upper and lower rolls 85, 86 is gradually set smaller than the thickness of the rolled material 88 with the adjusting handle 87.

  Next, the manufacturing method until the laminated product 81 of Embodiment 1 of the present invention is bonded by diffusion bonding to form the hydrogen permeable separation membrane 21 and the operation during the diffusion bonding step will be described with reference to the process diagram of FIG. To do.

  In order to manufacture the hydrogen permeable membrane 21 having the composite multilayer structure according to the first embodiment of the present invention, first, a Ta foil as the first metal foil 79 having a thickness of 200 μm, which is a base metal having a high hydrogen permeation performance, and a metal hydrogen A 5 μm thick Mo foil 90, which is a modified metal second metal foil 80 that is difficult to form a chemical compound, is prepared, and cleaning, degreasing, etching, and the like are performed in a pretreatment process.

  Specifically, the surface of the Ta foil of the first metal foil 79 that becomes the first metal layer 48 of the base metal having a high hydrogen permeation coefficient is degreased with acetone, and then immersed in hydrofluoric acid having a concentration of about 0.1 mol for 20 minutes. Treat it with sufficient water washing and azeotropic drying with alcohol. Further, the Mo foil of the second metal foil 80 serving as the modified metal is degreased with acetone and then washed with hot water at 40 ° C.

  Next, in the repeating step, first, in the laminating step A, ten Ta foil first metal foils 79 and Mo foil second metal foils 80 are alternately laminated to form a laminated product 81, and a pressing plate jig 77b is placed with a carbon fiber felt subjected to high purity treatment as a peelable sheet 82b, and a laminate 81 is set thereon.

  Further, the same peelable sheet 82 a and the pressing flat plate jig 77 a are sequentially placed thereon, and lightly tightened with the support bolts 78 a and 78 b to prepare as the press member 73.

  Next, in the diffusion bonding step A, the vacuum chamber 61 of the diffusion bonding apparatus 23 is removed from the pin 68 of the connecting portion 67, the upper chamber 64 is moved upward, and the vacuum chamber 61 is opened. Next, the heat insulating wall 69 of the high temperature diffusion furnace 62 is opened, the prepared press member 73 is set on the lower stage 72 of the hydraulic press 63 in the middle, the heat insulating wall 69 is closed, and the vacuum chamber 61 is fixed. The vacuum chamber 61 is sealed by returning the position and fixing the connecting portion 67 with the pin 68.

  Next, the vacuum pump 66 is operated, the degree of vacuum in the vacuum chamber 61 is lowered to 10 −5 Pa or less, the heater power is turned on, and the controller 71 raises the temperature to 900 ° C. After confirming the rise, the hydraulic press 63 is driven, the upper stage 73 is lowered, the press member 73 is pressurized so that a pressure of about 0.1 MPa is applied, and left at 900 ° C. for 2 hours.

  Thereafter, the heater power is turned off and the furnace is cooled to 50 ° C. to complete the diffusion bonding step A, whereby a primary diffusion bonded product is obtained.

  When the press member 73 is pressurized, the first metal foil 79 and the second metal foil 80 are deformed while the peelable sheets 82a and 82b made of a highly purified carbon fiber felt that is elastically deformed by the pressure are deformed. Is uniformly adhered, and the bonding interface of each metal foil surface adheres to the entire surface, whereby diffusion bonding is smoothly performed.

  Next, after cooling to 50 ° C., a rolling process A in which a 2050 μm primary diffusion bonded product prepared by diffusion bonding with the two-stage rolling mill 20 is rolled to 180 μm is entered.

  As rolling process A, it sets so that it may become a compression ratio of 2 to 3% from the thickness of the primary diffusion joining goods which are to-be-rolled products, and it rolls by passing the clearance gap between upper and lower rolls 85 and 86 repeatedly. At this time, if the rolling direction is kept constant, peeling or deformation will occur unless the device is made to reduce the strain of the laminated product.

  Next, a plate rolled to 180 μm is cut into a predetermined size of 10 sheets to obtain a primary rolled cut product, which is washed as necessary, and the rolled cut product is again laminated by the same operation in the laminating step A. Then, the diffusion bonding process A and the rolling process A are repeated.

  By repeating this process of repeating the lamination process A, diffusion bonding process A, rolling process A, and cutting four times, a stack of about 10,000 sheets is realized.

  Next, after repeating the above repeating step four times, the catalyst metal layer forming step 94 is started.

  In the lamination step B in the catalyst metal layer forming step 94, a laminate of 10 composite core laminates 51 obtained by cutting into a predetermined size in the previous cutting step is prepared, and the second metal foil 80 is prepared. The same 5 μm Mo foil is washed with hot water, and a 50 μm Pd foil obtained by simple pickling is prepared.

  Next, as the lamination step B, a high-purity carbon fiber felt as a peelable sheet 82b is placed on the same pressing plate jig 77b as used in the lamination step A, and the catalyst metal foil 91 and the outermost metal foil 91 are placed thereon. The Mo foil 90 to be the upper and lower layers 50, the composite core laminate 51 in which the previous 10 sheets were laminated, the Mo foil 90 to be the uppermost lower layer 50, and the catalytic metal foil 91 were set, and from above, the same A peelable sheet 82 a and a pressing flat plate jig 77 a are sequentially placed and lightly tightened with support bolts 78 a and 78 b to prepare a laminate 81 on the press member 73.

  Next, the diffusion bonding step B is the same as the diffusion bonding step A, but the vacuum chamber 61 of the diffusion bonding apparatus 23 is removed from the pin 68 of the connecting portion 67, the upper chamber 64 is moved upward, and the vacuum chamber 61 is opened. Next, the heat insulating wall 69 of the high temperature diffusion furnace 62 is opened, the prepared press member 73 is set on the lower stage 72 of the hydraulic press 63 in the middle, the heat insulating wall 69 is closed, and the vacuum chamber 61 is fixed. The vacuum chamber 61 is sealed by returning the position and fixing the connecting portion 67 with the pin 68.

Next, the vacuum pump 66 is operated, the degree of vacuum in the vacuum chamber 61 is lowered to 10 ⁻⁵ Pa or less, the heater power is turned on, and the controller 71 raises the temperature to 900 ° C. After confirming the rise, the hydraulic press 63 is driven to lower the upper stage 74 to pressurize the press member 73 so that a pressure of about 0.1 MPa is applied, and left at 900 ° C. for 2 hours.

  Thereafter, the heater power supply is turned off and the furnace is cooled to 50 ° C. to complete the diffusion bonding step B, whereby a final diffusion bonded product is obtained.

  When the press member 73 is pressurized, the peelable sheets 82a and 82b made of highly purified carbon fiber felt that is elastically deformed by the pressure are sandwiched between the 50 μm Pd foil and the 5 μm Mo foil while being deformed. Diffusion bonding is smoothly performed when the laminated product 81 is uniformly adhered and the bonding interface is adhered on the entire surface.

  Next, after cooling to 50 ° C., a rolling process B in which a final diffusion bonded product of about 1500 μm created by diffusion bonding with the two-stage rolling mill 20 is rolled to 50 μm is entered.

  The rolling process B is set to have a compression ratio of 2% to 3% based on the thickness of the final diffusion bonded product, which is a rolled product, and the rolling process B is repeatedly passed through the gaps between the upper and lower rolls 85 and 86 as in the rolling process A. Roll.

  By the lamination step B, diffusion bonding step B, and rolling step B in the catalytic metal layer forming step, a composite multilayer structure hydrogen permeable membrane having the composite core laminate 51 as a core material is obtained, and the membrane is separated by hydrogen generation and separation. Attach the device 22 at a predetermined position.

  In addition, by interposing a 5 μm Mo foil serving as the uppermost lower layer 50, the interdiffusion under the heating conditions in the diffusion bonding step B of the Ta metal in the composite core laminate 51 to the Pd catalyst metal layer 52 is suppressed. And the deterioration of the hydrogen permeation performance of the hydrogen permeable membrane can be prevented.

  In addition, this rolling operation has an effect of preventing a very thin oxide film generated at each metal layer interface from being broken and preventing a decrease in hydrogen permeation performance.

  The operation of the hydrogen generation / separation apparatus 22 to which the hydrogen permeable membrane 21 having the composite multilayer structure configured as described above is attached will be described below.

  When the reaction chamber 25 is heated to 800 ° C. by the operation of the heating means 34 and hydrocarbon methane and water vapor are supplied to the reaction chamber 25 of the hydrogen generator / separator 22 from the supply port 31, the interface of the reforming catalyst 33 of the communicating Ni foam is formed. Thus, as in (Chemical Formula 1), in addition to the generation of hydrogen and carbon dioxide by the reaction in which methane is oxidized by water vapor and the water vapor is reduced, the catalyst is brought into contact with the Pd catalyst metal layer 52 of the hydrogen permeable separation membrane 21. The action promotes the reaction and produces hydrogen.

生成された水素は水素透過分離膜２１の触媒金属層５２のＰｄ触媒により、水素分子が水素原子に解離され、複合多層構造の水素透過膜２１内に固溶される。触媒金属層５２の表面層は１００％のＰｄ濃度層であり触媒能力は非常に高く維持されている。

The generated hydrogen is dissociated into hydrogen atoms by the Pd catalyst of the catalytic metal layer 52 of the hydrogen permeable separation membrane 21 and is dissolved in the hydrogen permeable membrane 21 having a composite multilayer structure. The surface layer of the catalytic metal layer 52 is a 100% Pd concentration layer, and the catalytic ability is kept very high.

  The dissolved hydrogen atoms flow toward the separation chamber 26 due to the difference in hydrogen concentration between the reaction chamber 25 and the separation chamber 26, and after passing through the Pd catalyst metal layer 52, the Mo lowermost layer 50 and Mo and Ta are densely packed. Flows through the composite core laminated body 51, and again permeates the Mo lowermost layer 50, and is again combined with hydrogen molecules from hydrogen atoms by the Pd catalyst of the catalytic metal layer 52 on the separation chamber 26 side as the hydrogen gas. Flow into.

  At this time, the central portion of the hydrogen permeable membrane 21 having a composite multilayer structure is a composite core laminate material of Ta and Mo having a high hydrogen permeation performance, so that hydrogen atoms are diffused very quickly and further separated. Since the metal coating layer 52 on the chamber 24 side is a Pd catalyst metal layer 52 having a concentration of 100%, bonding from hydrogen atoms to hydrogen molecules is also performed quickly.

  If the surface is only a Pd metal with a catalytic gold enhancement layer and the center is only a base metal monolayer such as Ta as in the conventional example, mutual diffusion between Pd and Ta is gradually caused by heating at 800 ° C. for a long time. As a result, Ta is deposited on the surface of the Pd layer, and the formation of an oxide film of Ta on the surface layer causes the hydrogen permeable film to be extremely deteriorated. Further, Ta metal is a metal that is relatively easy to be hydrogen embrittled, and due to temperature change caused by operation and stop of the apparatus, the strength deteriorates due to hydrogen embrittlement, and the film cannot be self-supported and is destroyed.

  However, in this embodiment, the uppermost lower layer 51 of Mo suppresses interdiffusion between Ta and Pd, and the composite core laminate 51 of Ta and Mo is alloyed by diffusion of Mo into Ta. In addition to suppressing hydrogen embrittlement, the Ta metal layer is divided as a very thin layer, so that the structural disconnection between metals proceeds, so the volume expansion in the metal hydride is suppressed and the effect of suppressing hydrogen embrittlement is achieved. It works even more strongly.

  Mo is a metal that is difficult to form a metal hydride, and has an effect of suppressing interdiffusion between Ta and Pd. In addition to suppressing the precipitation of Ta element on the surface of the Pd coating layer, Mo is contained in the Ta layer. Has the effect of suppressing the hydrogen embrittlement of Ta.

  Next, the other mixed gas remaining in the reaction chamber 25 flows downstream on the discharge port 32 side, generates hydrogen gas by the same reaction, and similarly flows into the separation chamber 26 through the hydrogen separation membrane 21.

  That is, when flowing from the supply port 31 to the discharge port 32, hydrogen sequentially flows out from the reaction chamber 25 through the hydrogen permeable membrane 21 having a composite multilayer structure, so that the hydrogen gas concentration of the flowing gas does not reach an equilibrium state even downstream. The hydrogen gasification reaction (Chemical Formula 1) is performed smoothly, and in the vicinity of the discharge port 32, most of the circulating gas is discharged as carbon dioxide.

  Normally, the hydrogen ratio of the flowing gas increases as it goes downstream, reaches an equilibrium state, and does not react any more, but in the reaction chamber 25, the reaction continues because the hydrogen gas moves to the separation chamber 26. Done.

  As can be understood from this description, Pd constituting the catalytic metal layer 52 has a catalytic function for promoting dissociation / recombination of hydrogen and a function for permeating hydrogen. Further, Mo constituting the second metal layer 49 with the modified metal and Ta constituting the first metal layer 48 with the base metal have a function of allowing hydrogen to permeate. Note that the hydrogen permeation performance of Ta is considerably superior to the hydrogen permeation performance of Pd.

  In the present embodiment, since a sleeve gas such as water vapor is introduced into the separation chamber 26 from the introduction port 39 and flows through the separation chamber 26, the hydrogen remaining in the spacer 46 portion of the hydrogen permeable membrane 21 having the composite multilayer structure is washed away. The hydrogen concentration in the vicinity of the Pd layer of the metal layer 52 does not increase, and a pressure partial pressure difference always occurs, and smooth diffusion and movement of hydrogen is performed in the reaction chamber 25 and the separation chamber 26.

  In the present embodiment, 5 μm Mo foil 90 is additionally used in the catalyst metal formation step as the uppermost layer 50, but the effect of suppressing interdiffusion between Ta and Pd is more reliably performed. Therefore, it is possible to cope with the problem by devising the orientation of the laminated product so that the second metal layer faces the Pd catalyst metal layer 52 without using the Mo foil again.

  In this embodiment, Ta is used as the first metal layer of the base metal, but any metal plate having a high hydrogen permeation coefficient can be applied, and in particular, transition metals such as Ta, Nb, V, and the like. This alloy is effective and is not limited to Ta.

  Further, in this embodiment, as the material of the peelable sheet 77, carbon fiber felt (Nihon Carbon Co., Carboron, GF-20-2F) purified at about 2000 ° C. was used, but 1000 ° C. or more. The silica fiber non-woven fabric (Advantech Toyo Co., Ltd., silica fiber filter paper, QR-100) purified with a high purity is good due to the pressure applied to the appropriate bonding interface in terms of surface denseness, and high at about 2000 ° C. Purified graphite (Nihon Carbon Co., Nika Film, FL-300SH) has the same effect, does not generate gas due to heat, is elastically deformed by pressurization, and the first metal foil 79 and the second metal foil 80. It is possible to use a material having good releasability from the catalyst metal foil 91 and the pressurizing flat plate jigs 77a and 77b, and is not limited to the felt of carbon fiber.

  Further, in this embodiment, as an initial laminated product, a product obtained by laminating 10 sheets of Ta foil and Mo foil each is a laminated product, and diffusion bonding and rolling are repeated four times, and a layer corresponding to 10,000 sheets. The composite core laminate was formed, but the effect of destroying the oxide film on the surface of each metal layer can be obtained by performing diffusion bonding and rolling at least once, so that the hydrogen permeation performance does not deteriorate The repeating process is not limited to four times.

  Further, in this embodiment, the total thickness of the composite core laminate is designed to be 50 μm and the thickness of one sheet of the first metal layer is 5 nm. However, when the total thickness is 1 μm or less, the strength capable of supporting itself as a film However, if the total thickness is 200 μm or more, the hydrogen permeation performance is extremely lowered, and if the thickness of one first metal layer is 100 nm or more, the structural breakage of the metal layer is not sufficient, The effect of suppressing hydrogen embrittlement is reduced.

  In the present embodiment, the ratio of the thickness of the second metal layer to the first metal layer of the composite core laminate is designed to be 2% in terms of element ratio. The effect of suppressing the hydrogen embrittlement of Ta becomes extremely small, and if it becomes 10% or more, the hydrogen permeation performance is extremely lowered, and it is configured with an allocation corresponding to 0.05% to 10%. For example, it is possible to obtain a hydrogen embrittlement suppressing effect and maintain hydrogen permeation performance.

  Thus, if the uppermost lower layer of Mo is interposed between the first metal layer made of the Ta base metal and the Pd catalytic metal layer, the interdiffusion of Ta metal is suppressed in the Pd catalytic metal layer. It is possible to reduce the deterioration of hydrogen permeation characteristics due to diffusion.

  As described above, in the present embodiment, the case where Ta is used as the first metal layer, Mo is used as the second metal layer, and Pd is used as the catalyst metal layer, but Nb having the same properties as this instead of Ta is used. V or an alloy thereof may be used, Re may be used instead of Mo or an alloy thereof, or Pd alloy may be used instead of Pd. Also good. Also in this case, the above description can be applied in the same manner, and thus a detailed description is omitted.

  As described above, the hydrogen permeable membrane having the composite multilayer structure and the manufacturing method thereof according to the present embodiment are easily diffused between the Pd catalyst metal layer and the base metal first metal layer. The second metal layer that is difficult to diffuse is formed, the mutual diffusion between the first metal layer and the catalyst metal layer is suppressed, the catalytic function of the surface layer is maintained, and the first metal layer and the second metal layer are Because diffusion bonding and rolling are performed by heat treatment in the multilayered state in which the layers are alternately stacked, hydrogen embrittlement is suppressed by the solid solution of the first metal layer and the second metal layer and the effect of ultrathin film stacking. However, there can be provided a hydrogen permeable membrane having no pinholes, good permeation separation performance of high purity hydrogen, and high performance hydrogen permeation.

  As described above, the hydrogen permeable membrane of the composite multilayer structure according to the present invention is used not only in the field of fuel cells using the hydrogen permeable membrane, but also for hydrogen generator for gas chromatograph analysis and surface modification in a semiconductor manufacturing factory. It can be used not only for hydrogen generators that are used, but also for promoting reaction kettles that have a reaction that generates hydrogen as an intermediate substance, and can also be used effectively for making equipment such as hydrogen generators inexpensively. .

1 is a schematic configuration diagram of a hydrogen generation / separation device incorporating a hydrogen permeable membrane having a composite multilayer structure according to Embodiment 1 of the present invention. Enlarged sectional view of the hydrogen permeable membrane having the composite multilayer structure of the embodiment Section A enlarged sectional view of the hydrogen permeable membrane of the composite multilayer structure of the same embodiment Schematic cross-sectional configuration diagram showing a diffusion bonding apparatus for diffusion bonding metal foil bodies in the same embodiment The expanded sectional view which shows the press member of the diffusion bonding apparatus in the embodiment Sectional drawing which shows the cross section in the rolling process state of the rolling mill in the embodiment Process drawing which shows the manufacturing method of the hydrogen permeable membrane of the composite multilayer structure of the embodiment Cross section of a conventional hydrogen permeable membrane Perspective view of a conventional hydrogen permeable membrane Perspective view of a tube using a conventional hydrogen permeable membrane

Explanation of symbols

21 Hydrogen Permeation Membrane 48 First Metal Layer 49 Second Metal Layer 50 Uppermost Lower Layer 51 Composite Core Laminate 52 Catalytic Metal Layer 79 First Metal Foil 80 Second Metal Foil 81 Laminated Product 91 Catalytic Metal Foil

Claims (9)

  A composite core laminate comprising a composite core laminate in which a first metal layer made of a base metal having high hydrogen permeation performance and a second metal layer that is a modified metal that is difficult to form a metal hydride are laminated alternately. A hydrogen permeable membrane having a composite multi-layer structure in which a catalytic metal layer made of Pd or a Pd alloy is formed on both sides.   A composite core in which a first metal layer made of a base metal having high hydrogen permeation performance and a second metal layer that is a modified metal that is difficult to form a metal hydride are alternately laminated, and the uppermost lower layer is the second metal layer. A hydrogen permeable membrane having a composite multilayer structure in which a catalyst metal layer made of Pd or a Pd alloy is formed on both surfaces of the composite core laminate.   3. The hydrogen permeable membrane having a composite multilayer structure according to claim 1, wherein the base metal having a high hydrogen permeation performance of the first metal layer is a VA group metal of a high melting point transition metal having a body-centered cubic structure or an alloy thereof.   The base metal having high hydrogen permeation performance of the first metal layer is any one of Ta, Nb, V, Ta alloy, Nb alloy, and V alloy, which are high melting point transition metals having a body-centered cubic structure. 4. A hydrogen permeable membrane having a composite multilayer structure according to any one of 3 above.   The hydrogen permeation of the composite multilayer structure according to any one of claims 1 to 4, wherein the second metal layer that is a modified metal that is difficult to form a metal hydride is Mo, Re, a Mo alloy, or a Re alloy. film.   The hydrogen permeable membrane having a composite multilayer structure according to any one of claims 1 to 5, wherein the composite core laminate is formed by repeating at least one diffusion bonding and rolling.   The hydrogen permeable membrane of a composite multilayer structure according to any one of claims 1 to 6, wherein the total thickness of the composite core laminate is 1 to 200 µm and the thickness of one sheet of the first metal layer is 100 nm or less.   The ratio of the thickness of the 1st metal layer of a composite core laminated body and the 2nd metal layer was comprised in the distribution equivalent to 0.05% to 10% in conversion of an element ratio. A hydrogen permeable membrane having a composite multilayer structure according to one item.   A lamination process in which a plurality of first metal foils made of a base metal having high hydrogen permeation performance and second metal foils, which are modified metals that are difficult to form metal hydrides, are alternately laminated to form a laminate, and the laminate is heated. And a diffusion bonding step in which diffusion bonding is performed by pressure and pressure to form a diffusion bonded product, a rolling step in which the diffusion bonded product is rolled to a predetermined thickness to form a rolled composite core laminate, and a composite core laminate is further laminated as necessary. A composite multilayer structure comprising: a repeated lamination and rolling process in which a rolling process is repeated to form a composite core laminate; and a catalyst metal layer forming process for forming a catalyst metal foil made of Pd or a Pd alloy on both surfaces of the composite core laminate. A method for manufacturing a permeable membrane.

Images