JP2007245010A - Hydrogen refining filter and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydrogen refining filter having superior hydrogen permeation efficiency in hydrogen refining, and a manufacturing method for easily manufacturing such a filter. <P>SOLUTION: The structure of the hydrogen refining filter comprises a diffusion preventive layer disposed on one face of a porous support body; a Pd alloy film disposed on the porous support body to cover a lot of pores of the porous support body via the diffusion preventive layer; and an annular outer frame member positioned in the region of the outside of the Pd alloy film and at least one face of the porous support body. A thickness of the outer frame member is set thicker than that of the Pd alloy film. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a hydrogen purification filter and a method for producing the same, and more particularly to a hydrogen purification filter used in a reformer or the like for steam reforming various hydrocarbon fuels to produce a hydrogen rich gas, The present invention relates to a manufacturing method that can be manufactured.

In recent years, global environmental and energy / resource problems have become apparent, and fuel cells have been attracting attention as one of energy supply systems that harmonize these with industry. A fuel cell directly produces hydrogen gas or hydrogen-rich gas obtained by reforming a hydrocarbon-based fuel such as natural gas, gasoline, butane gas, or methanol by electrochemical reaction with oxygen in the air. It is the electric power generating apparatus which takes out. The fuel cell using the hydrogen-rich gas includes a reformer that generates hydrogen-rich gas by steam reforming a hydrocarbon-based fuel, a fuel cell body that generates electricity, a converter that converts the generated DC electricity into AC, and the like It consists of
Such a fuel cell may be a phosphoric acid fuel cell (PAFC), a molten carbonate fuel cell (MCFC), a solid electrolyte fuel cell (SOFC), an alkaline type, depending on the electrolyte used in the fuel cell body, the reaction mode, and the like. There are five types of fuel cells (AFC) and polymer electrolyte fuel cells (PEFC). Among these, the polymer electrolyte fuel cell (PEFC) is advantageous in that the electrolyte is solid compared to other fuel cells such as a phosphoric acid fuel cell (PAFC) and an alkaline fuel cell (AFC). Have the requirements.

However, the polymer electrolyte fuel cell (PEFC) uses platinum as the catalyst and has a low operating temperature, so that the electrode catalyst is poisoned by a small amount of CO, and the performance deterioration is particularly remarkable in a high current density region. There is. For this reason, it is necessary to reduce the CO concentration contained in the reformed gas (hydrogen-rich gas) generated by the reformer to about 10 ppm.
As one of the means for purifying hydrogen by removing CO from the reformed gas, a hydrogen purification filter having a Pd alloy film has been developed. In particular, only hydrogen is permeable, and the reformed gas side is set to a high temperature and high pressure (for example, 500 ° C., 3 to 10 kg / cm ² (0.29 to 0.98 MPa)), thereby achieving a low hydrogen partial pressure side. Permeates hydrogen.

  In the hydrogen refining method using the Pd alloy film as described above, the hydrogen permeation rate is inversely proportional to the film thickness, so that a thin film is required. However, from the viewpoint of mechanical strength, the Pd alloy film alone is about 30 μm. In the case of using a Pd alloy film having a film thickness of about several tens of μm, a porous support was disposed on the low hydrogen partial pressure side of the Pd alloy film. However, since the Pd alloy film and the support are separately mounted on the reformer, the workability for obtaining good sealing is poor, and the Pd alloy film and the support are rubbed to cause the Pd alloy film. There was a problem that the durability of was not sufficient.

In order to solve the above problem, a hydrogen purification filter in which a Pd alloy film is directly formed on a support and the Pd alloy film and the support are integrated has been developed. For example, a Pd alloy film is formed on a temporary support, a resist pattern is formed on the Pd alloy film, and then a metal base having fine openings so as to cover 30 to 95% of the Pd alloy film. There is a hydrogen purification filter manufactured by forming a film by electrolytic plating and then removing the temporary support (Patent Document 1). Further, a metal plate is arranged on one surface of the conductive substrate having a through hole, and a copper plating layer is formed so as to fill the through hole by copper plating from the other surface of the conductive substrate. There is a hydrogen purification filter manufactured by removing the metal film, forming a Pd alloy film on the surface, and removing the copper plating layer by selective etching (Patent Document 2).
JP 2002-292259 A JP 2004-57866 A

However, in the above-described hydrogen purification filter of Patent Document 1, it takes a long time to form the metal base film on the Pd alloy film by electrolytic plating, and the formation of a thick metal base film having sufficient strength is difficult. There was a problem that it was difficult. There is also a problem that the resist is likely to remain in the fine opening of the formed metal base film.
Further, the hydrogen purification filter of Patent Document 2 described above has voids in the copper plating layer, particularly in the deep part of the through hole (part where the Pd alloy film is formed in the subsequent process) in the step of filling the through hole by copper plating. In some cases, a void that is not filled with copper plating is generated, and in the process of forming the Pd alloy film, this void may cause pinhole defects in the Pd alloy film. For this reason, process management has become complicated, which has hindered the reduction of manufacturing costs.

Furthermore, the conventional hydrogen purification filter in which the Pd alloy film is directly formed on one surface of the support is warped due to the stress of the Pd alloy film, and is difficult to handle during the manufacturing process and during assembly and mounting. There was a problem. Such warpage can be prevented by increasing the thickness of the support, but there is a demand for thinning of the hydrogen purification filter, and when the thickness of the support is about 10 to 50 μm, it is effective in preventing warpage. It was difficult to respond properly. Further, there has been a problem that the use of the material for a long time at a high temperature diffuses the constituent material of the support into the Pd alloy film, resulting in a decrease in hydrogen permeation efficiency.
This invention is made | formed in view of the above situations, and provides the hydrogen purification filter which shows the hydrogen permeation efficiency excellent in hydrogen purification, and the manufacturing method for manufacturing such a filter simply. Objective.

  In order to achieve such an object, the hydrogen purification filter of the present invention comprises a porous support having a plurality of pores, a diffusion prevention layer disposed on one surface of the porous support, and the pores. A Pd alloy film disposed on the porous support through the diffusion prevention layer so as to cover, and an annular region located outside the Pd alloy film and located on at least one surface of the porous support An outer frame member, and the thickness of the outer frame member is equal to or greater than the thickness of the Pd alloy film.

As another aspect of the present invention, the diffusion preventing layer is configured to be one of titanium nitride, titanium carbide, silicon nitride, silicon carbide, magnesium oxide, cerium oxide, and zinc oxide.
As another aspect of the present invention, the porous support is made of stainless steel, and the outer frame member is made of iron or nickel.
As another aspect of the present invention, the porous support has a thickness in the range of 10 to 50 μm, and the Pd alloy film has a thickness in the range of 1 to 5 μm.
As another aspect of the present invention, the outer frame member has a width in the range of 1 to 5 mm.
As another aspect of the present invention, the outer frame member has a thickness that is 3 to 50 μm thicker than the Pd alloy film.

  Further, the method for producing a hydrogen purification filter of the present invention includes a film forming step of forming a diffusion prevention layer on the surface side of the support and forming a Pd alloy film on the diffusion prevention layer, and an outer region of the Pd alloy film. An outer frame member forming step of forming an annular outer frame member having a thickness equal to or greater than that of the Pd alloy film on the support, and a resist pattern in which a plurality of openings are located in a region inside the outer frame member Is formed on the back side of the support, and the support is etched from the back side using the resist pattern as a mask to form a plurality of through holes in the support, and then exposed to the through holes. And an etching step of removing the diffusion prevention layer by etching to produce a porous support.

As another aspect of the present invention, in the outer frame member forming step, an outer frame member made of iron or nickel is formed by electrolytic plating.
As another aspect of the present invention, in the film formation step, titanium nitride, titanium carbide, silicon nitride, silicon carbide, magnesium oxide, cerium oxide is formed by any one of vacuum deposition, ion plating, sputtering, and electroless plating. The diffusion preventing layer made of any of zinc oxide is formed.

Since the hydrogen purification filter of the present invention includes a diffusion prevention layer between the porous support and the Pd alloy film, the diffusion of the constituent material of the porous support into the Pd alloy film is surely prevented, and at a high temperature. High hydrogen permeation efficiency is maintained even when used for a long time, and the diffusion preventing layer ensures high adhesion with the porous support and the Pd alloy film, so that the durability is greatly improved. The annular outer frame member present in the region resists the stress of the Pd alloy film and prevents the hydrogen purification filter from warping. A purification filter is possible.
Further, in the method for producing a hydrogen purification filter of the present invention, a Pd alloy film is formed on a support through a diffusion prevention layer, so that the formed Pd alloy film has a uniform film thickness and high hydrogen permeation performance. In addition, since it is not necessary to add or remove a member that does not remain in the final hydrogen purification filter, the process becomes simple, and an annular outer frame member is attached before the etching process for producing the porous support. Since it forms, the hydrogen purification filter is prevented from warping in the state where the etching process is completed, and the handleability during the manufacturing process is good.

Embodiments of the present invention will be described below with reference to the drawings.
[Hydrogen purification filter]
FIG. 1 is a perspective view showing an embodiment of the hydrogen purification filter of the present invention, and FIG. 2 is a longitudinally enlarged partial sectional view taken along line AA of the hydrogen purification filter shown in FIG. 1 and 2, the hydrogen purification filter 1 includes a porous support 2 having a plurality of fine pores 3, and Pd disposed on the surface 2 a side of the porous support 2 via a diffusion prevention layer 5. The alloy film 6 and a region outside the Pd alloy film 6 and an annular outer frame member 8 positioned on the surface 2a side of the porous support 2 are provided. The thickness T of the outer frame member 8 is equal to or greater than the thickness of the Pd alloy film 6.
The porous support 2 constituting the hydrogen purification filter 1 can be produced using materials such as austenitic and ferritic stainless steel such as SUS304 and SUS430, and the thickness is appropriately set within a range of 10 to 50 μm. be able to.

The pores 3 of the porous support 2 preferably have an opening diameter in the range of 15 to 150 μm. In addition, the total area of the openings of the holes 3 in the region where the Pd alloy film 6 is disposed preferably occupies 20 to 80% of the area of the Pd alloy film 6. In addition, when there exists a difference in the opening diameter of the hole part 3 in the thickness direction of the porous support body 2, the said opening diameter means a minimum opening diameter.
The diffusion preventing layer 5 constituting the hydrogen purification filter 1 prevents the constituent material of the porous support 2 from diffusing into the Pd alloy film 6 and has high adhesion to the porous support 2 and the Pd alloy film 6. It is a layer for securing. Such a diffusion prevention layer 5 is a thin film made of a nitride, oxide, or carbide of one or more elements selected from Ti, Si, Al, Mg, Ce, Cr, Ca, Zr, etc. A thin film such as titanium nitride (TiN), titanium carbide (TiC), silicon nitride (SiN), silicon carbide (SiC), magnesium oxide (MgO), cerium oxide (CeO ₂ ), or zinc oxide (ZnO) can be formed. . Further, the diffusion preventing layer 5 may be a thin film made of a refractory metal such as Zr, Mo, Ta, W, Cr, Hf, Nb, Ru. The thickness of the diffusion preventing layer 5 can be appropriately set in consideration of the material, and can be, for example, about 0.01 to 20 μm, preferably about 0.5 to 2 μm.

  The Pd alloy film 6 constituting the hydrogen purification filter 1 usually has a Pd content of 60% by weight or more, and Ag, Cu, Pt, Au, Ni, Co, V, Nb, Ta, Zr and the like as additive elements. It contains 1 type or 2 types or more. The thickness of the Pd alloy film 6 is preferably as thin as possible from the viewpoint of improving the hydrogen permeation rate, but can be appropriately set within a range of 1 to 5 μm, for example.

The annular outer frame member 8 constituting the hydrogen purification filter 1 has a square cross section and resists the warpage of the Pd alloy film 6 in the structure in which the porous support 2 is provided only on one side of the Pd alloy film 6. It is arranged for the purpose of preventing. As described above, the thickness T of the outer frame member 8 is equal to or greater than the thickness of the Pd alloy film 6, and can be set to be 3 to 50 μm thicker than the thickness of the Pd alloy film 6, for example. If the thickness T of the outer frame member 8 is less than the thickness of the Pd alloy film 6, the hydrogen purification filter 1 is likely to warp, which is not preferable. The material of the outer frame member 8 may be iron, nickel, gold, silver, copper, or the like. In the present invention, the state in which warpage is prevented means that, when the hydrogen purification filter 1 is placed on a horizontal surface plate, the height variation from the surface plate to the surface of the Pd alloy film 6 is 3 mm or less. It means that.
Further, the width W of the annular outer frame member 8 can be set in the range of 1 to 5 mm, and the cross-sectional shape of the outer frame member 8 is rectangular in the illustrated example, but is not limited thereto. It may be trapezoidal, dome-shaped, or the like.

FIG. 3 is a cross-sectional view corresponding to FIG. 2 showing another embodiment of the hydrogen purification filter of the present invention. In FIG. 3, the hydrogen purification filter 11 includes a porous support 12 having a plurality of fine holes 13, and a Pd alloy film 16 disposed on the surface 12 a side of the porous support 12 via a diffusion prevention layer 15. And an annular outer frame member 18 located on the back surface 12b side of the porous support 12 in the region outside the Pd alloy film 16. The thickness T of the outer frame member 18 is equal to or greater than the thickness of the Pd alloy film 16.
This hydrogen purification filter 11 is the same as the hydrogen purification filter 1 described above except that an annular outer frame member 18 is provided on the back surface 12b side of the porous support 12. Accordingly, the porous support member 12, the diffusion prevention layer 15, the Pd alloy film 16, and the annular outer frame member 18 that constitute the hydrogen purification filter 11 are respectively the porous support member 2, the diffusion prevention layer 5, and the Pd alloy film. 6 and the annular outer frame member 8, and a description thereof is omitted here.

  FIG. 4 is a cross-sectional view corresponding to FIG. 2 showing another embodiment of the hydrogen purification filter of the present invention. In FIG. 4, the hydrogen purification filter 21 includes a porous support 22 having a plurality of fine pores 23, and a Pd alloy film 26 disposed on the surface 22 a side of the porous support 22 via a diffusion prevention layer 25. And an annular outer frame member 28a located on the surface 22a side of the porous support 22 and an annular outer frame member 28b located on the back surface 22b side of the porous support 22 in a region outside the Pd alloy film 26. Is provided. That is, the annular outer frame member 28 includes an outer frame member 28 a and an outer frame member 28 b that are positioned on each surface of the porous support 22. The thickness of the outer frame member 28 (the sum of the thickness T1 of the outer frame member 28a and the thickness T2 of the outer frame member 28b) is equal to or greater than the thickness of the Pd alloy film 26.

  This hydrogen purification filter 21 is the same as the above-described hydrogen purification filter 1 except that annular outer frame members 28 a and 28 b are provided on both surfaces of the porous support 22. Therefore, the porous support member 22, the diffusion prevention layer 25, and the Pd alloy film 26 constituting the hydrogen purification filter 21 are the same as the porous support member 2, the diffusion prevention layer 5, and the Pd alloy film 6 described above, respectively. be able to. The annular outer frame member 28 is the same as the annular outer frame member 8 except that the thicknesses T1 and T2 of the outer frame members 28a and 28b are equal to or greater than the thickness of the Pd alloy film 26. The description here will be omitted.

  Since the hydrogen purification filter of the present invention as described above includes the diffusion prevention layers 5, 15, 25 between the porous supports 2, 12, 22 and the Pd alloy films 6, 16, 26, the Pd alloy film 6, Diffusion of the constituent materials of the porous supports 2, 12, 22 into 16, 26 is reliably prevented, and high hydrogen permeation efficiency is maintained even when used for a long time at high temperatures. Further, since the diffusion preventing layers 5, 15, and 25 ensure high adhesion with the porous supports 2, 12, and 22 and the Pd alloy films 6, 16, and 26, they have excellent durability. Further, since the annular outer frame members 8, 18, 28a, 28b existing in the outer region of the Pd alloy films 2, 16, 26 counter the stress of the Pd alloy films 6, 16, 26, the porous support 2, Even if 12, 22 is thin, warping of the hydrogen purification filter is prevented.

  In addition, the above-mentioned embodiment is an illustration and the hydrogen purification filter of this invention is not limited to these. For example, in the above-described embodiment, the diffusion preventing layer is disposed on the entire surface of the porous support (even in a region where the Pd alloy film is not formed), but is disposed only directly below the Pd alloy film. It may be. In addition, the shape of the hydrogen purification filter is circular in the illustrated example, but can be any shape such as a square, a polygon, an ellipse, and accordingly, the shape of the diffusion preventing layer, the Pd alloy film, and The ring shape of the outer frame member can also be set as appropriate.

[Method for producing hydrogen purification filter]
Next, the manufacturing method of the hydrogen purification filter of this invention is demonstrated.
FIG. 5 and FIG. 6 are process diagrams showing an embodiment of the method for producing a hydrogen purification filter of the present invention, taking the above-described hydrogen purification filter 1 of the present invention as an example.
In the production method of the present invention, first, in the film formation step, the diffusion prevention layer 5 is formed on the surface 2'a side of the support 2 'for the porous support (FIG. 5A). A Pd alloy film 6 is formed thereon (FIG. 5B).
For the support 2 ', materials such as austenitic and ferritic stainless steel such as SUS304 and SUS430 can be used, and the thickness can be in the range of 10 to 50 µm.

The diffusion prevention layer 5 can be formed by a vacuum film formation method such as vacuum deposition, ion plating, sputtering, or electroless plating. Specifically, it can be formed as a thin film of nitride, oxide, or carbide of one or more elements selected from Ti, Si, Al, Mg, Ce, Cr, Ca, Zr, etc. Examples include thin films such as titanium nitride (TiN), titanium carbide (TiC), silicon nitride (SiN), silicon carbide (SiC), magnesium oxide (MgO), cerium oxide (CeO ₂ ), and zinc oxide (ZnO). The diffusion prevention layer 5 can also be formed as a thin film of a refractory metal such as Zr, Mo, Ta, W, Cr, Hf, Nb, Ru. In the case where the diffusion preventing layer 5 is formed in a desired portion of the support 2 ', a resist pattern can be provided in a non-formed portion or can be formed through a desired mask.

  The Pd alloy film 6 can be formed by electrolytic plating. It is also possible to form a Pd alloy film 6 by component diffusion by laminating a thin film of each component constituting the Pd alloy on the diffusion prevention layer 5 by electrolytic plating or electroless plating, and then performing heat treatment. In this case, for example, Pd can be formed to a thickness of 3 μm by plating, Ag can be formed to a thickness of 1 μm by plating, and then subjected to heat treatment at 500 ° C. for 24 hours to form a Pd alloy. . Further, heat treatment may be performed after performing multi-layer plating such as a Pd / Ag / Pd3 layer and a Pd / Ag / Pd / Ag4 layer. The thickness of the Pd alloy film 6 to be formed can be about 1 to 5 μm.

  Next, in the outer frame member forming step, an annular outer frame member 8 is formed in a region outside the Pd alloy film 6 (FIG. 5C). In the manufacturing example of the hydrogen purification filter 1, the outer frame member 8 is formed on the surface 2'a side of the support 2 '. However, in the manufacture of the hydrogen purification filter 11, the outer frame member is formed on the back surface side of the support. Further, in the manufacture of the hydrogen purification filter 21 described above, the outer frame members are formed on the front surface side and the back surface side of the support. The outer frame member 8 can be formed, for example, by forming a resist pattern in a non-formed portion and depositing iron, nickel, gold, silver, copper, or the like by electrolytic plating. The thickness of the outer frame member 8 to be formed is equal to or greater than the thickness of the Pd alloy film 6, and can be set to be 3 to 50 μm thicker than the thickness of the Pd alloy film 6, for example.

Next, in an etching process, a resist pattern 9 is formed on the back surface 2'b side of the support 2 '(FIG. 6A). The resist pattern 9 includes a plurality of openings 9a in a region inside the outer frame member 8, that is, a region facing the Pd alloy film 6 through the support 2 '. Next, the support 2 'is etched from the back surface 2'b side using the resist pattern 9 as a mask, thereby forming a plurality of through holes 3 in the support 2' (FIG. 6B). Thereafter, the diffusion preventing layer 5 exposed in these through holes 3 is removed by selective etching to produce a porous support 2 (FIG. 6C). Thereby, the hydrogen purification filter 1 is obtained.
Etching of the support 2 'can be performed by using a ferric chloride-based etching solution by a spray method from the back surface, a dipping method only on the back surface, or the like. By such etching of the support 2 'from the back surface 2'b side, the through-hole 3 to be formed usually has a large opening on the back surface 2'b side. In this case, in order to maintain the strength and hydrogen permeation efficiency of the porous support 2 at a high level, the minimum opening diameter (on the surface 2′a side) of the through hole 3 is 1.5 to 1.5 mm of the thickness of the support 2 ′. The opening 9a of the resist pattern 9 is three times larger and the maximum opening diameter of the through hole 3 (on the back surface 2'b side) is 3.5 to 5 times the thickness of the support 2 '. It is preferable to set etching conditions.

Further, the selective etching of the diffusion preventing layer 5 can be performed by appropriately selecting an etching solution in consideration of the material of the diffusion preventing layer 5. For example, when the support 2 'is stainless steel and the diffusion prevention layer 5 is titanium nitride, hydrogen peroxide can be used as an etching solution. The resist pattern 9 can be removed using an alkaline aqueous solution or the like.
In the manufacturing method of the present invention as described above, the Pd alloy film 6 is formed on the flat surface of the support 2 'via the diffusion prevention layer 5, so that it is possible to form the Pd alloy film 6 having a uniform thickness. is there. In addition, since the annular outer frame member 8 is formed before the etching step for producing the porous support 2, warpage in the state where the etching step is completed is prevented, and the handleability during the manufacturing process is good. Furthermore, since there is no member addition / removal process that does not remain in the final hydrogen purification filter 1, the process becomes simple.

Next, the present invention will be described in more detail by showing more specific examples.
[Example 1]
A circular (35 mm diameter) SUS304 material having a thickness of 40 μm was prepared as a support. Next, a photosensitive resist material (OFPR manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied to both surfaces of this SUS304 material by a dipping method (application amount: 7 μm (when dry)). Next, the resist coating film on one surface was exposed through a photomask having a circular opening with an opening diameter of 30 mm, and developed using sodium hydrogen carbonate. Thus, a resist pattern was formed so that only one surface of the SUS304 material was exposed as a circle having a diameter of 30 mm.
Next, a thin film of titanium nitride (thickness 0.5 μm) was formed on the circular exposed portion of the SUS304 material by a vacuum vapor deposition method to form a diffusion preventing layer.

Next, a Pd alloy film (thickness 5 μm) was formed on the diffusion prevention layer by electrolytic plating under the following conditions, and then the resist pattern was removed using sodium hydroxide. (End of film formation process)
(Pd alloy film deposition conditions)
-Bath used: Pd chloride plating bath (Pd concentration: 12 g / L)
・ PH: 7-8
・ Current density: 1 A / dm ²
・ Liquid temperature: 40 ℃

  Next, a photosensitive resist material (OFPR manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied to both surfaces of the SUS304 material on which the diffusion preventing layer and the Pd alloy film are formed as described above (application amount: 10 μm (when dried)). did. Thereafter, a photomask having an annular opening having a width of 3 mm (the inner diameter of the opening is 31 mm) is located at the peripheral edge of the SUS304 material on the surface on which the diffusion prevention layer and the Pd alloy film are formed. The resist coating film was exposed through this photomask and developed using sodium hydrogen carbonate. As a result, a resist pattern was formed such that only the peripheral portion (region outside the Pd alloy film) of the SUS304 material on the surface on which the diffusion prevention layer and the Pd alloy film were formed was exposed in an annular shape with a width of 3 mm.

Next, a Ni film (thickness: 10 μm) was formed on the annular exposed portion of the SUS304 material by Ni electrolytic plating under the following conditions to obtain an outer frame member. Thereafter, the resist pattern was removed using sodium hydroxide. (End of outer frame member forming process)
(Ni electrolytic plating conditions)
・ Use bath: Nickel chloride bath ・ Liquid temperature: 55 ℃
・ Current density: 10 A / dm ²

  Next, a photosensitive resist material (OFPR manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied to the back surface of the SUS304 material by a dipping method (application amount: 7 μm (when dry)). Next, a photomask provided with a plurality of circular openings having an opening size (opening diameter) of 90 μm at a pitch of 120 μm is disposed on the resist coating film, and the resist coating film is exposed through the photomask, and sodium hydrogen carbonate. Developed using Thus, a resist pattern having a circular opening having an opening dimension (opening diameter) of 90 μm was formed on the back side of the SUS304 material.

Next, using the resist pattern as a mask, the SUS304 material was etched by spraying from the back side under the following conditions.
(Etching conditions)
・ Temperature: 50 ℃
・ Ferric chloride concentration: 45 Baume ・ Pressure: 0.30 MPa

After the above etching treatment was completed, the resist pattern was removed using sodium hydroxide and washed with water. Thereby, a through hole was formed in the SUS304 material to obtain a porous support. These through holes are all formed in the region where the Pd alloy film is formed. Each through hole has an opening size (opening diameter) of 95 μm on the back side of the SUS304 material. The surface side opening dimension (opening diameter) was 70 μm.
Next, using a hydrogen peroxide solution as a selective etching solution for the diffusion preventing layer, the diffusion preventing layer exposed in the inner part of the through hole was selectively removed by etching and washed with water. (End of etching process)
Through the above steps, the hydrogen purification filter of the present invention as shown in FIGS. 1 and 2 was obtained.

As a result of placing the hydrogen purification filter prepared as described above on a horizontal surface plate and measuring the height from the surface plate to the surface of the Pd alloy film, the height variation is 3 mm or less and there is no warpage. Was confirmed.
In addition, a hydrogen purification filter is attached to the reformer, and a mixture of methanol and water vapor is supplied to the Pd alloy membrane for 100 hours continuously under high temperature and high pressure conditions (500 ° C., 0.50 MPa), and permeates to the porous support side of the hydrogen purification filter. The CO concentration of the hydrogen rich gas and the flow rate of the hydrogen rich gas were measured. As a result, the CO concentration from the start of reforming to the elapse of 300 hours is as extremely low as 5 to 10 ppm, and the flow rate of the hydrogen rich gas is 1 L / min, and the hydrogen purification filter of the present invention has excellent durability. The hydrogen permeation efficiency was confirmed.

[Example 2]
As shown in FIG. 3, in the same manner as in Example 1, except that the annular outer frame member is formed on the peripheral edge of the back surface side (the surface on which the diffusion preventing layer and the Pd alloy film are not formed) of the SUS304 material. Thus, a hydrogen purification filter of the present invention was obtained.
The produced hydrogen purification filter was placed on a horizontal surface plate, and the height from the surface plate to the surface of the Pd alloy film was measured. As a result, the height variation was 3 mm or less, and it was confirmed that there was no warp. .
In addition, a hydrogen purification filter is attached to the reformer, and a mixture of methanol and water vapor is supplied to the Pd alloy membrane of the filter under the same high-temperature and high-pressure conditions as in Example 1, and CO of hydrogen-rich gas that permeates to the porous support side of the filter. The concentration and the flow rate of the hydrogen rich gas were measured. As a result, the CO concentration from the start of reforming to the elapse of 300 hours is as extremely low as 5 to 10 ppm, and the flow rate of the hydrogen rich gas is 1 L / min, and the hydrogen purification filter of the present invention has excellent durability. The hydrogen permeation efficiency was confirmed.

[Comparative Example 1]
A hydrogen purification filter was obtained in the same manner as in Example 1 except that the annular outer frame member was not formed.
The produced hydrogen purification filter was placed on a horizontal platen, and the height from the platen to the surface of the Pd alloy film was measured. As a result, the height variation was 7 mm, and it was confirmed that warpage occurred. It was done.

[Comparative Example 2]
A hydrogen purification filter was obtained in the same manner as in Example 1 except that the thickness of the annular outer frame member was 2 μm.
The produced hydrogen purification filter was placed on a horizontal surface plate, and the height from the surface plate to the surface of the Pd alloy film was measured. As a result, the height variation was 5 mm, and it was confirmed that warpage occurred. It was done.

[Comparative Example 3]
A hydrogen purification filter was obtained in the same manner as in Example 1 except that the diffusion prevention layer was not formed.
The produced hydrogen purification filter was placed on a horizontal surface plate, and the height from the surface plate to the surface of the Pd alloy film was measured. As a result, the height variation was 3 mm or less, and it was confirmed that there was no warp. .
In addition, a hydrogen purification filter is attached to the reformer, and a mixture of methanol and water vapor is supplied to the Pd alloy membrane of the filter under the same high-temperature and high-pressure conditions as in Example 1, and CO of hydrogen-rich gas that permeates to the porous support side of the filter. The concentration and the flow rate of the hydrogen rich gas were measured. As a result, the CO concentration from the start of reforming to the elapse of 100 hours was as extremely low as 5 to 10 ppm, and the flow rate of the hydrogen rich gas was 1 L / min. The CO concentration exceeded 10 ppm, the amount of gas leakage increased, and the purity of the hydrogen-rich gas decreased.

  It can be used in various fields that require high-purity hydrogen-rich gas.

It is a perspective view which shows one Embodiment of the hydrogen purification filter of this invention. FIG. 2 is a longitudinally enlarged partial sectional view taken along line AA of the hydrogen purification filter shown in FIG. 1. It is a fragmentary sectional view equivalent to FIG. 2 which shows other embodiment of the hydrogen purification filter of this invention. It is a fragmentary sectional view equivalent to FIG. 2 which shows other embodiment of the hydrogen purification filter of this invention. It is process drawing which shows one Embodiment of the manufacturing method of the hydrogen purification filter of this invention. It is process drawing which shows one Embodiment of the manufacturing method of the hydrogen purification filter of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,11,21 ... Hydrogen refinement | purification filter 2,12,22 ... Porous support body 3,13,23 ... Hole 5,15,25 ... Diffusion prevention layer 6,16,26 ... Pd alloy film 8,18,28, 28a, 28b ... outer frame member 2 '... support 9 ... resist pattern 9a ... opening

Claims (9)

  A porous support having a plurality of pores, a diffusion prevention layer disposed on one surface of the porous support, and disposed on the porous support via the diffusion prevention layer so as to cover the pores A Pd alloy film, and an annular outer frame member located on at least one surface of the porous support in a region outside the Pd alloy film, and the thickness of the outer frame member is the same as that of the Pd alloy film. A hydrogen purification filter having a thickness equal to or greater than the thickness.   2. The hydrogen purification filter according to claim 1, wherein the diffusion prevention layer is one of titanium nitride, titanium carbide, silicon nitride, silicon carbide, magnesium oxide, cerium oxide, and zinc oxide.   The hydrogen purification filter according to claim 1 or 2, wherein the porous support is stainless steel, and the outer frame member is iron or nickel.   4. The hydrogen according to claim 1, wherein the porous support has a thickness in the range of 10 to 50 μm, and the Pd alloy film has a thickness in the range of 1 to 5 μm. Purification filter.   5. The hydrogen purification filter according to claim 1, wherein a width of the outer frame member is in a range of 1 to 5 mm. 6. The hydrogen purification filter according to claim 1, wherein a thickness of the outer frame member is 3 to 50 [mu] m thicker than the Pd alloy film. In the method for producing a hydrogen purification filter,
Forming a diffusion preventing layer on the surface side of the support, and forming a Pd alloy film on the diffusion preventing layer; and
An outer frame member forming step of forming an annular outer frame member having a thickness equal to or greater than that of the Pd alloy film on the support in the outer region of the Pd alloy film;
A resist pattern having a plurality of openings located in a region inside the outer frame member is formed on the back side of the support, and the support is etched from the back side using the resist pattern as a mask. Forming a porous support by forming a plurality of through holes in the body and then removing the diffusion prevention layer exposed in the through holes by etching to produce a porous support. Method.   The method for manufacturing a hydrogen purification filter according to claim 7, wherein in the outer frame member forming step, an outer frame member made of iron or nickel is formed by electrolytic plating.   In the film forming step, any one of vacuum deposition, ion plating, sputtering, and electroless plating is used, and the film is formed of any one of titanium nitride, titanium carbide, silicon nitride, silicon carbide, magnesium oxide, cerium oxide, and zinc oxide. The method for producing a hydrogen purification filter according to claim 7 or 8, wherein the diffusion preventing layer is formed.

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