Tubular palladium-vanadium / iron-palladium composite membrane as well as preparation method and application thereof

Abstract

The invention relates to a tubular palladium-vanadium / iron-palladium composite membrane as well as a preparation method and application thereof. The tubular palladium-vanadium / iron-palladium composite film comprises a tubular V / Fe alloy matrix and palladium layers formed on the inner surface and the outer surface of the tubular V / Fe alloy matrix. The tubular V / Fe alloy matrix is sequentially immersed in a tin salt solution and a first palladium salt solution for sensitization and activation treatment, after cleaning and blow-drying, the tubular V / Fe alloy matrix is immersed in a second palladium salt-ethidene diamine chemical plating solution, a hydrazine hydrate solution is added for a reaction, and the palladium layers are formed on the inner surface and the outer surface of the tubular V / Fe alloy matrix in a chemical plating mode. And the tubular palladium-vanadium / iron-palladium composite membrane is obtained. Compared with the prior art, the material cost can be greatly reduced, the hydrogen permeation rate can be increased, the mechanical strength can be improved, and the service life of the composite membrane tubular assembly can be prolonged.

Description

Technical Field

[0001] This invention relates to the field of hydrogen purification technology, and in particular to a tubular palladium-vanadium / iron-palladium composite membrane, its preparation method, and its application. Background Technology

[0002] The production of high-purity hydrogen is a crucial step in high-end technology fields such as fuel cells, semiconductor manufacturing, and fine chemicals. Currently, the main sources of high-purity hydrogen include fossil fuel-based hydrogen production routes such as coal-to-hydrogen and natural gas steam methane reforming, as well as industrial by-product hydrogen production based on coke oven gas and ammonia synthesis processes. After initial purification, hydrogen purity can typically reach 90% to 99.9%, but further purification is still needed to meet the stringent purity requirements of industries such as fuel cells (requiring hydrogen purity higher than 99.999%) and semiconductor manufacturing. However, impurities such as carbon monoxide (CO), nitrogen (N2), methane (CH4), and hydrogen sulfide (H2S) often remain in the aforementioned hydrogen production and by-product gases. These impurities can seriously affect the performance and safety of downstream devices, especially threatening the electrochemical reactions and long-term stability of fuel cells. Therefore, developing efficient and reliable hydrogen purification technologies is of significant practical importance.

[0003] Currently used methods for further purification of high-purity hydrogen include adsorption and cryogenic distillation, but these processes generally suffer from high energy consumption, complex equipment structures, and poor operational flexibility. In contrast, membrane separation technology, with its advantages of simple operation, low energy consumption, and ease of system integration and scale-up, has gradually become a research hotspot in the field of hydrogen purification.

[0004] Among various hydrogen separation membranes, dense metal membranes, represented by palladium and its alloys, have made some progress in material design, structural optimization, and industrial application. These membranes utilize the dissolution-diffusion mechanism of hydrogen atoms in the metal lattice to achieve efficient hydrogen separation. However, traditional palladium membranes still face problems such as high material cost and insufficient mechanical strength. Of particular concern is that pure palladium membranes are prone to hydrogen embrittlement during operation and are easily deactivated by sulfide poisoning in sulfur-containing atmospheres, limiting their large-scale commercial application. Although alloying (such as Pd-Ag, Pd-Cu, etc.) can improve these problems to some extent, for example, by adjusting lattice gaps and surface energy to promote the dissolution and diffusion of hydrogen atoms, the thickness of existing Pd alloy membranes is usually still above 20 μm. Excessive thickness leads to low hydrogen permeation flux, while material costs remain high. To reduce palladium usage and increase flux, research has attempted to deposit palladium or its alloy membranes several micrometers thick onto the surface of porous rigid supports (such as ceramics, porous stainless steel, glass, etc.). Although this type of composite structure has improved cost control, its hydrogen permeation flux is still difficult to meet actual production needs. The main reasons include the unsatisfactory porosity and pore size distribution of the porous matrix, as well as the insufficient integrity and adhesion strength of the membrane layer on the carrier surface, which in turn affects the selectivity and long-term operational reliability of the membrane.

[0005] Another promising class of hydrogen separation membrane materials consists of Group V metals (such as vanadium, niobium, and tantalum) and their body-centered cubic (BCC) alloys. Theoretical studies have shown that the bulk diffusion rate of hydrogen in these materials is several orders of magnitude higher than that in face-centered cubic palladium-based alloys. However, Group V metal membranes still have significant limitations in practical hydrogen separation applications: firstly, a dense oxide layer easily forms on the surface of these metals, hindering the dissociation and adsorption process of hydrogen molecules and causing surface reaction control steps; secondly, these materials typically have high hydrogen solubility, which can easily lead to hydrogen embrittlement and affect the mechanical stability of the membrane.

[0006] The problem of excessive hydrogen solubility in vanadium can be effectively solved through alloying, with iron exhibiting significant advantages as an alloying element. Iron not only significantly reduces the solubility of hydrogen in the vanadium matrix by replacing matrix positions in the vanadium lattice, but its body-centered cubic structure, identical to that of pure vanadium, also provides a structural basis for the formation of disordered solid solutions. Vanadium-iron alloys based on this disordered body-centered cubic structure exhibit exceptionally superior hydrogen diffusion properties, with their hydrogen diffusivity even surpassing that of pure vanadium under certain conditions. In existing high-purity hydrogen production processes, hydrogen-containing mixed gases typically require treatment through a palladium membrane purification unit. This process relies on the selective permeation characteristics of the palladium membrane for hydrogen; hydrogen molecules dissociate into hydrogen atoms on the membrane surface, dissolve, diffuse to the other side of the membrane, and recombine to form hydrogen molecules, thus achieving efficient separation and purification of hydrogen. Impurity gases that fail to permeate the membrane (such as CO2, CO, N2, etc.) and some residual hydrogen are discharged from the exhaust port. However, existing palladium membranes often suffer from reduced airtightness and poor structural reliability due to insufficient mechanical strength during actual operation, which in turn has a significant adverse effect on the purity of the final product, hydrogen. Summary of the Invention

[0007] The purpose of this invention is to overcome the defects of the prior art, such as insufficient strength, insufficient air tightness, and poor reliability of palladium membranes, which lead to poor hydrogen purity, and to provide a tubular palladium-vanadium / iron-palladium composite membrane, its preparation method and application, so as to significantly reduce material costs, increase hydrogen permeation rate, improve mechanical strength, and enhance the service life of the composite membrane tubular component.

[0008] The objective of this invention can be achieved through the following technical solutions: One of the technical solutions of the present invention is to provide a tubular palladium-vanadium / iron-palladium composite film, which includes: a tubular V / Fe alloy substrate, and a palladium layer formed on the inner and outer surfaces of the tubular V / Fe alloy substrate.

[0009] Furthermore, in the tubular V / Fe alloy matrix, the atomic percentage content of Fe is 5 at% to 30 at%.

[0010] Furthermore, the wall thickness of the tubular V / Fe alloy matrix is ​​150~500μm; The thickness of the palladium layer on the inner and outer surfaces is independently 2~10 μm.

[0011] Furthermore, the tubular V / Fe alloy matrix has a length of 10~40cm and a diameter of 0.4~1cm.

[0012] The second technical solution of the present invention provides a method for preparing a tubular palladium-vanadium / iron-palladium composite film. The tubular V / Fe alloy substrate is sequentially immersed in a tin salt solution and a first palladium salt solution for sensitization and activation treatment, cleaned, dried, and then immersed in a second palladium salt-ethylenediamine chemical plating solution. A hydrazine hydrate solution is added to react, and the palladium layer is formed on the inner and outer surfaces of the tubular V / Fe alloy substrate by chemical plating to obtain a tubular palladium-vanadium / iron-palladium composite film.

[0013] Furthermore, the tin salt solution includes one or more of stannous chloride, stannous bromide, stannous iodide, stannous sulfate, and stannous methanesulfonate solution; The first palladium salt solution and the second palladium chloride solution are each independently one or more of the following: palladium chloride solution, palladium bromide solution, palladium iodide solution, palladium nitrate solution, and palladium acetate solution. The concentration of the tin salt solution is 2.0 × 10⁻⁶. -3 ~6.0×10 -3 mol / L; The concentration of the first palladium salt solution is 3.0 × 10⁻⁶. -4 ~6.0×10 -4 mol / L; The concentration of the second palladium salt in the second palladium salt-ethylenediamine electroless plating solution is 4~8 g / L, and the concentration of ethylenediamine is 10~15 g / L; The concentration of the hydrazine hydrate solution is 30 wt% ~ 90 wt%; The volume ratio of the hydrazine hydrate solution to the second palladium salt-ethylenediamine electroless plating solution is 4~12mL:1L; The reaction temperature is 40~60℃ and the time is 1~3h.

[0014] The third technical solution of the present invention is to provide an application of a tubular palladium-vanadium / iron-palladium composite membrane, characterized in that the tubular palladium-vanadium / iron-palladium composite membrane is used to purify hydrogen from a hydrogen-containing gas mixture.

[0015] Furthermore, the tubular palladium-vanadium / iron-palladium composite membrane is used to prepare a hydrogen purification device. The hydrogen purification device includes a shell and a first chamber, a second chamber, and a third chamber disposed within the shell. The first chamber is provided with an air inlet, the second chamber is provided with a first air outlet, and the third chamber is provided with a second air outlet. The third chamber is provided with a plurality of spaced composite membrane storage chambers, each containing a tubular palladium-vanadium / iron-palladium composite membrane. Each composite membrane storage chamber has a first channel and a second channel at its two ends. The first channel communicates with the second chamber, and the second channel is located within the third chamber. The composite membrane storage chamber is connected to the first chamber via a gas supply pipe.

[0016] Furthermore, the gas supply pipe is connected to the inner or outer side of the tubular palladium-vanadium / iron-palladium composite membrane.

[0017] Furthermore, when the gas supply pipe is connected to the inner side of the tubular palladium-vanadium / iron-palladium composite membrane, the hydrogen purification device is an internal pressure hydrogen purification device, the first channel serves as the impurity gas discharge channel, the second channel serves as the purified hydrogen discharge channel, the first outlet serves as the total outlet for impurity gas, and the second outlet serves as the total outlet for purified hydrogen. When the gas supply pipe is connected to the outside of the tubular palladium-vanadium / iron-palladium composite membrane, the hydrogen purification device is an external pressure hydrogen purification device. The first channel serves as the purified hydrogen discharge channel, the second channel serves as the impurity gas discharge channel, the first outlet serves as the total purified hydrogen outlet, and the second outlet serves as the total impurity gas outlet.

[0018] Furthermore, the two ends of the purified hydrogen discharge channel are provided with secondary purification membranes made of palladium or its alloy.

[0019] Furthermore, the palladium alloy includes other multi-element alloys such as Pd-Ag, Pd-Au, Pd-Cu, Pd-Fe, and Pd-Ag-Au.

[0020] Furthermore, the housing is made of pressure-resistant and corrosion-resistant metal materials (such as 316L stainless steel).

[0021] Furthermore, the tubular palladium-vanadium / iron-palladium composite membrane is arranged circumferentially along the third chamber, and the outer surface of the composite membrane storage chamber is fixedly sealed to the inner wall of the third chamber.

[0022] Furthermore, the tubular palladium-vanadium / iron-palladium composite membrane is welded to the inner wall of the third chamber using argon arc welding, and the weld is inspected. The sealing specifications require no obvious holes or cracks after welding, a firm bond, and a leakage rate ≤1×10⁻⁶. -9 Pa•m 3 / s.

[0023] Furthermore, the inner and outer ends of the purified hydrogen exhaust channel are fixed with a secondary purification membrane made of palladium or its alloy by argon arc welding.

[0024] Furthermore, a gas flow gap is reserved between the inner wall of the shell and the outer surface of the tubular palladium-vanadium / iron-palladium composite membrane to ensure that impurity gases can be fully discharged, avoiding membrane surface blockage or decreased permeation efficiency due to accumulation.

[0025] Furthermore, the operation process of the hydrogen purification device is as follows: S1. Introduce raw material gas: Introduce hydrogen-containing mixed gas into the first chamber through the gas inlet, and then transport it to the feed side of the tubular palladium-vanadium / iron-palladium composite membrane through the gas supply pipe; S2. Hydrogen separation and purification: Under the conditions of operating temperature of 350℃~650℃, operating pressure of 100Pa~1.2MPa, and pressure difference across the composite membrane ≤0.3MPa, hydrogen selectively permeates through the composite membrane to its permeation side under the drive of pressure difference and concentration gradient. S3. Product Output: The purified hydrogen from the permeation side is collected through the corresponding purified hydrogen discharge channel and output from the total purified hydrogen outlet; the impurity gas that has not permeated is collected through the corresponding impurity gas discharge channel and output from the total impurity gas outlet.

[0026] Furthermore, the hydrogen content in the hydrogen-containing mixture is 90% to 99.9%.

[0027] Compared with the prior art, the present invention has the following advantages: (1) Traditional palladium membranes are expensive and prone to hydrogen embrittlement and sulfur poisoning. While metals such as vanadium and niobium have extremely high bulk hydrogen diffusion rates, their surfaces are easily passivated and have high hydrogen solubility, making them susceptible to hydrogen embrittlement. This invention creatively uses a tubular V / Fe alloy as the substrate. The addition of Fe effectively regulates the hydrogen solubility of the substrate and significantly enhances mechanical stability. The key is that by preparing ultrathin palladium layers on both sides of the substrate, the excellent hydrogen dissociation catalytic activity of palladium is utilized to perfectly solve the problem of slow reaction kinetics on the surface of Group V metals. This composite structure of "palladium catalytic surface + V / Fe fast diffusion channel" achieves functional synergy at the molecular level, enabling the membrane to maintain high selectivity while having a theoretical hydrogen permeation flux far exceeding that of traditional palladium membranes, and fundamentally improving the material's resistance to poisoning.

[0028] (2) The tubular integral structure and its preparation process of the present invention significantly improve the mechanical strength and long-term operational reliability of the membrane. Designing the composite membrane as a self-supporting tubular body, compared with thin films deposited on porous carriers, results in a qualitative leap in structural integrity and pressure resistance, effectively avoiding the risk of failure caused by carrier defects or coating peeling. Through an optimized chemical plating process, a micron-level dense palladium layer is formed on the V / Fe substrate, which ensures uniform coating and strong bonding. This integrated structure enables it to withstand greater thermal stress and operating pressure difference when welded and sealed with the shell, completely improving the common problems of poor airtightness and sealing failure in traditional palladium membrane modules, and providing a solid guarantee for the stable operation of the device under variable temperature and pressure conditions.

[0029] (3) The purification device of the present invention is equipped with multiple parallel composite membrane storage chambers, which greatly improves the hydrogen processing efficiency per unit volume. Its innovation lies in defining two operating modes: internal pressure and external pressure. Users can flexibly choose according to the inlet pressure and maintenance requirements, which enhances the adaptability of the working conditions. In particular, a secondary purification membrane is set in the pure hydrogen outlet channel, which constitutes a two-level guarantee of "coarse purification + refining". It can effectively intercept trace amounts of impurities that may leak from the microscopic defects that may exist in the main membrane, ensuring that the purity of the produced hydrogen is consistently higher than 99.999%, meeting the application requirements of the most demanding fields.

[0030] (4) The purification device provided by the invention can not only effectively reduce material and processing costs, but also significantly improve the mechanical strength and stability of the composite membrane, and exhibit a longer service life in long-term operation; and through its tubular composite membrane structure design, it significantly improves the hydrogen permeation rate, thereby enhancing the overall processing capacity and lifespan of the device. Attached Figure Description

[0031] Figure 1 A schematic cross-sectional view of the tubular palladium-vanadium / iron-palladium composite membrane shown in this invention; Figure 2 This is a schematic diagram of the internal pressure hydrogen purification device shown in this invention; Figure 3 This is a schematic diagram of the external pressure purification device shown in this invention.

[0032] Explanation of markings in the diagram 1-Tube-shaped palladium-vanadium / iron-palladium composite film, 11-Tube-shaped V / Fe alloy substrate, 12-Palladium layer; 2-Shell; 3-First chamber, 31-Air inlet; 4-Second chamber, 41-First air outlet; 5-Third chamber, 51-Second air outlet; 6-Composite membrane storage chamber; 61-First channel; 62-Second channel; 63-Secondary purification membrane; 7-Gas supply pipe. Detailed Implementation

[0033] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments. In the following embodiments or examples, unless otherwise specified, the functional components or structures are conventional components or structures used in the art to achieve the corresponding functions.

[0034] It should be noted that in the description of this invention, the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0035] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0036] A tubular palladium-vanadium / iron-palladium composite film 1 includes: a tubular V / Fe alloy substrate 11, and palladium layers 12 formed on the inner and outer surfaces of the tubular V / Fe alloy substrate 11.

[0037] In some specific embodiments, the atomic percentage content of Fe in the tubular V / Fe alloy matrix 11 is 5 at% to 30 at%.

[0038] In some specific embodiments, the wall thickness of the tubular V / Fe alloy matrix 11 is 150~500μm; The thickness of the palladium layer 12 on the inner and outer surfaces is independently 2~10 μm.

[0039] In some specific embodiments, the tubular V / Fe alloy substrate 11 has a length of 10~40cm and a diameter of 0.4~1cm.

[0040] A method for preparing a tubular palladium-vanadium / iron-palladium composite film involves immersing a tubular V / Fe alloy substrate 11 sequentially in a tin salt solution and a first palladium salt solution for sensitization and activation, cleaning, drying, and then immersing it in a second palladium salt-ethylenediamine chemical plating solution. A hydrazine hydrate solution is added to react, and the palladium layer 12 is formed on the inner and outer surfaces of the tubular V / Fe alloy substrate 11 by chemical plating to obtain a tubular palladium-vanadium / iron-palladium composite film.

[0041] In some specific embodiments, the tin salt solution includes one or more of stannous chloride, stannous bromide, stannous iodide, stannous sulfate, and stannous methanesulfonate solution; The first palladium salt solution and the second palladium chloride solution are each independently one or more of the following: palladium chloride solution, palladium bromide solution, palladium iodide solution, palladium nitrate solution, and palladium acetate solution. The concentration of the tin salt solution is 2.0 × 10⁻⁶. -3 ~6.0×10 -3 mol / L; The concentration of the first palladium salt solution is 3.0 × 10⁻⁶. -4 ~6.0×10 -4 mol / L; The concentration of the second palladium salt in the second palladium salt-ethylenediamine electroless plating solution is 4~8 g / L, and the concentration of ethylenediamine is 10~15 g / L; The concentration of the hydrazine hydrate solution is 30 wt% ~ 90 wt%; The volume ratio of the hydrazine hydrate solution to the second palladium salt-ethylenediamine electroless plating solution is 4~12mL:1L; The reaction temperature is 40~60℃, and the time is 1~3h. A third technical solution of the present invention provides an application of a tubular palladium-vanadium / iron-palladium composite membrane, characterized in that the tubular palladium-vanadium / iron-palladium composite membrane is used to purify hydrogen from a hydrogen-containing gas mixture.

[0042] In some specific embodiments, the tubular palladium-vanadium / iron-palladium composite membrane is used to prepare a hydrogen purification device. The hydrogen purification device includes a shell 2 and a first chamber 3, a second chamber 4, and a third chamber 5 disposed in the shell 2. The first chamber 3 is provided with an air inlet 31, the second chamber 4 is provided with a first air outlet 41, and the third chamber 5 is provided with a second air outlet 51. The third chamber 5 is provided with a plurality of spaced composite membrane storage chambers 6. The composite membrane storage chamber 6 is provided with a tubular palladium-vanadium / iron-palladium composite membrane 1. The two ends of the composite membrane storage chamber 6 are respectively provided with a first channel 61 and a second channel 62. The first channel 61 is connected to the second chamber 4, and the second channel 62 is located in the third chamber 5. The composite membrane storage chamber 6 is connected to the first chamber 3 via a gas supply pipe 7.

[0043] In some specific embodiments, the gas supply pipe 7 is connected to the inner or outer side of the tubular palladium-vanadium / iron-palladium composite membrane 1.

[0044] In some specific embodiments, when the gas supply pipe 7 is connected to the inner side of the tubular palladium-vanadium / iron-palladium composite membrane 1, the hydrogen purification device is an internal pressure hydrogen purification device, the first channel 61 serves as an impurity gas discharge channel, the second channel 62 serves as a purified hydrogen discharge channel, the first outlet 41 serves as the total outlet of impurity gas, and the second outlet 51 serves as the total outlet of purified hydrogen. When the gas supply pipe 7 is connected to the outside of the tubular palladium-vanadium / iron-palladium composite membrane 1, the hydrogen purification device is an external pressure hydrogen purification device. The first channel 61 serves as the purified hydrogen discharge channel, the second channel 62 serves as the impurity gas discharge channel, the first outlet 41 serves as the purified hydrogen total outlet, and the second outlet 51 serves as the impurity gas total outlet.

[0045] In some specific embodiments, the two ends of the purified hydrogen discharge channel are further provided with secondary purification membranes 63 made of palladium or its alloy.

[0046] In some specific embodiments, the palladium alloy includes other multi-element alloys such as Pd-Ag, Pd-Au, Pd-Cu, Pd-Fe, and Pd-Ag-Au.

[0047] In some specific embodiments, the housing is made of a pressure-resistant and corrosion-resistant metal material (such as 316L stainless steel).

[0048] In some specific embodiments, the tubular palladium-vanadium / iron-palladium composite membrane 1 is arranged circumferentially along the third chamber 5, and the outer surface of the composite membrane storage chamber 6 is fixedly sealed to the inner wall of the third chamber 5.

[0049] In some specific embodiments, the tubular palladium-vanadium / iron-palladium composite membrane 1 is welded to the inner wall of the third chamber 5 by argon arc welding, and the weld is inspected. The sealing specifications require that there be no obvious holes or cracks after welding, and that the bond is firm; the leakage rate ≤1×10⁻⁶. -9 Pa•m 3 / s.

[0050] In some specific embodiments, the secondary purification membrane 63 is fixed at both ends of the purified hydrogen exhaust channel by argon arc welding.

[0051] In some specific embodiments, a gas flow gap is reserved between the inner wall of the housing 2 and the outer surface of the tubular palladium-vanadium / iron-palladium composite membrane 1 to ensure that impurity gases can be fully discharged and avoid membrane surface blockage or decreased permeation efficiency due to accumulation.

[0052] In some specific embodiments, the operation process of the hydrogen purification device is as follows: S1. Introduce raw material gas: Introduce hydrogen-containing mixed gas into the first chamber 3 through the gas inlet 31, and transport it to the feed side of the tubular palladium-vanadium / iron-palladium composite membrane 1 through the gas supply pipe 7. S2. Hydrogen separation and purification: Under the conditions of operating temperature of 350℃~650℃, operating pressure of 100Pa~1.2MPa, and pressure difference across composite membrane 1 ≤0.3MPa, hydrogen selectively permeates through composite membrane 1 to its permeate side under the drive of pressure difference and concentration gradient. S3. Product Output: The purified hydrogen from the permeation side is collected through the corresponding purified hydrogen discharge channel and output from the total purified hydrogen outlet; the impurity gas that has not permeated is collected through the corresponding impurity gas discharge channel and output from the total impurity gas outlet.

[0053] In some specific embodiments, the hydrogen content in the hydrogen-containing gas mixture is 90% to 99.9%.

[0054] Each of the above embodiments can be implemented individually or in any combination of two or more.

[0055] The following description uses specific examples to illustrate the point.

[0056] Example 1 The preparation of a tubular palladium-vanadium / iron-palladium composite film includes the following steps: (1) A tubular V / Fe alloy substrate 11 with a length of 25 cm, a diameter of 0.6 cm, a thickness of 500 μm, and an Fe atomic percentage of 10 at% was chemically activated by sequentially immersing it in a solution with a concentration of 3.0 × 10⁻⁶. -3 A SnCl2 solution with a concentration of 4.0 × 10⁻⁶ mol / L and a SnCl₂ solution with a concentration of 4.0 × 10⁻⁶ mol / L. -4 Sensitization and activation were performed in a mol / L PdCl2 solution with an activation time of 15 min. (2) The tubular V / Fe alloy matrix 11 was cleaned with deionized water and dried with nitrogen to obtain the activated tubular V / Fe alloy matrix 11. (3) A palladium layer 12 is chemically plated on the upper and lower surfaces of a tubular V / Fe alloy substrate 11. The substrate is immersed in a chemical plating solution containing 6 g / L PdCl2 and 13 g / L ethylenediamine. The reaction temperature is 50°C. A 10 mL / L 80 wt% hydrazine hydrate solution is added. The palladium plating reaction on the tubular V / Fe alloy substrate 11 is carried out for 120 min to obtain a tubular palladium-vanadium / iron-palladium composite film 1. The tubular palladium-vanadium / iron-palladium composite film 1 includes a tubular V / Fe alloy substrate 11 and palladium layers 12 formed on the inner and outer surfaces of the tubular V / Fe alloy substrate 1. The tubular V / Fe alloy substrate 11 has a wall thickness of 500 μm. The palladium layer 12 on the inner surface of the tubular V / Fe alloy substrate 12 has a thickness of 4 μm, and the palladium layer 12 on the outer surface of the tubular V / Fe alloy substrate 12 has a thickness of 4 μm. Figure 1 As shown.

[0057] like Figure 2 As shown, the tubular palladium-vanadium / iron-palladium composite membrane is used in a purification device. The hydrogen purification device is an internal pressure hydrogen purification device, which includes: a shell 2 and a first chamber 3, a second chamber 4, and a third chamber 5 disposed in the shell 2. The first chamber 3 is provided with an air inlet 31, the second chamber 4 is provided with a first air outlet 41, and the third chamber 5 is provided with a second air outlet 51. The third chamber 5 is provided with a plurality of spaced composite membrane storage chambers 6. The composite membrane storage chamber 6 is provided with a tubular palladium-vanadium / iron-palladium composite membrane 1. The two ends of the composite membrane storage chamber 6 are respectively provided with a first channel 61 and a second channel 62. The first channel 61 is connected to the second chamber 4, and the second channel 62 is located in the third chamber 5. The composite membrane storage chamber 6 is connected to the inside of the first chamber 3 through a gas supply pipe 7; the first channel 61 serves as an impurity gas discharge channel, the second channel 62 serves as a purified hydrogen gas discharge channel, the first outlet 41 serves as the total outlet for impurity gases, and the second outlet 51 serves as the total outlet for purified hydrogen gases.

[0058] In this embodiment, a palladium-made secondary purification membrane 63 is provided at both ends of the purified hydrogen exhaust channel (i.e., the second channel 62).

[0059] In this embodiment, a gas flow gap is reserved between the inner wall of the housing 2 and the outer surface of the tubular palladium-vanadium / iron-palladium composite membrane 1 to ensure that impurity gases can be fully discharged and to avoid membrane surface blockage or decreased permeation efficiency due to accumulation.

[0060] In this embodiment, the tubular palladium-vanadium / iron-palladium composite membrane 1 is provided with four parallel sections, which are evenly spaced.

[0061] The procedure for using this tubular palladium-vanadium / iron-palladium composite membrane in a purification device for hydrogen purification is as follows: (1) Clean and dry each component of the purification device, remove surface oil and other impurities, weld the tubular palladium-vanadium / iron-palladium composite membrane 1 to the stainless steel shell by argon arc welding, and inspect the weld seam. Then, install it into the cleaned purification device. (2) The secondary purification membrane 63 is fixed at both ends of the second channel 62 by argon arc welding; (3) The purification device is heated to 400°C using an external heating device (conventional technology in the art); (4) A mixture of 99.5% hydrogen gas enters the first chamber 3 through the inlet 31. The pressure difference of the tubular palladium-vanadium / iron-palladium composite membrane 1 is 0.25 MPa. The gas is introduced into the inner side of the tubular palladium-vanadium / iron-palladium composite membrane 1 through the gas supply pipe 7. (5) Under the action of pressure difference and concentration gradient, hydrogen first dissolves on the inner palladium film 12 surface of tubular palladium-vanadium / iron-palladium composite film 1, then diffuses through palladium layer 12 in atomic state, then migrates to the other side through the metal lattice gap of tubular V / Fe alloy substrate 11, and then permeates out of outer palladium film 12. (6) The purified hydrogen is further purified by the secondary purification membrane 63. The second channel 62 serves as the purified hydrogen discharge channel, from which it is discharged in the form of high-purity hydrogen. The second outlet 51 serves as the total outlet of purified hydrogen and is connected to external equipment to output high-purity hydrogen. (7) The impurity gas that has not been permeated is discharged through the first channel 61 (as the impurity gas discharge channel) and the first outlet 41 (as the total outlet of the impurity gas) at the top of the purification device.

[0062] Tests have shown that the hydrogen purification device based on the tubular Pd-V / Fe-Pd composite membrane of this invention can purify 99.5% hydrogen into 99.9997% high-purity hydrogen, with a total hydrogen permeation flux of 59.2 scc / s and a hydrogen recovery rate of 99.6%.

[0063] Example 2 The preparation of a tubular palladium-vanadium / iron-palladium composite film includes the following steps: (1) A tubular V / Fe alloy substrate 11 with a length of 35 cm, a diameter of 0.8 cm, a thickness of 2000 μm, and an Fe atomic percentage of 15 at% was chemically activated by sequentially immersing it in a solution with a concentration of 5.0 × 10⁻⁶. -3 A SnCl2 solution with a concentration of 5.0 × 10⁻⁶ mol / L and a SnCl₂ solution with a concentration of 5.0 × 10⁻⁶ mol / L. -4 Sensitization and activation were performed in a mol / L PdCl2 solution for 20 min. (2) The tubular V / Fe alloy matrix 11 was cleaned with deionized water and dried with nitrogen to obtain the activated tubular V / Fe alloy matrix 11. (3) A palladium layer 12 is electrolessly plated onto the upper and lower surfaces of a tubular V / Fe alloy substrate 11. The substrate is immersed in an electroless plating solution containing 8 g / L PdCl2 and 11 g / L ethylenediamine. The reaction temperature is 45°C, and 8 mL / L 50 wt% hydrazine hydrate solution is added. The palladium plating reaction on the tubular V / Fe alloy substrate 11 is carried out for 180 min to obtain a tubular palladium-vanadium / iron-palladium composite film 1. The tubular palladium-vanadium / iron-palladium composite film 1 includes a tubular V / Fe alloy substrate 11 and palladium layers 12 formed on the inner and outer surfaces of the tubular V / Fe alloy substrate 1. The wall thickness of the tubular V / Fe alloy substrate 11 is 2000 μm. The palladium layer 12 on the inner surface of the tubular V / Fe alloy substrate 12 has a thickness of 6 μm, and the palladium layer 12 on the outer surface of the tubular V / Fe alloy substrate 12 has a thickness of 6 μm.

[0064] The tubular palladium-vanadium / iron-palladium composite membrane is used in a purification device. The hydrogen purification device is an internal pressure hydrogen purification device, which includes: a shell 2 and a first chamber 3, a second chamber 4, and a third chamber 5 disposed in the shell 2. The first chamber 3 is provided with an air inlet 31, the second chamber 4 is provided with a first air outlet 41, and the third chamber 5 is provided with a second air outlet 51. The third chamber 5 is provided with a plurality of spaced composite membrane storage chambers 6. The composite membrane storage chamber 6 is provided with a tubular palladium-vanadium / iron-palladium composite membrane 1. The two ends of the composite membrane storage chamber 6 are respectively provided with a first channel 61 and a second channel 62. The first channel 61 is connected to the second chamber 4, and the second channel 62 is located in the third chamber 5. The composite membrane storage chamber 6 is connected to the inside of the first chamber 3 through a gas supply pipe 7; the first channel 61 serves as an impurity gas discharge channel, the second channel 62 serves as a purified hydrogen gas discharge channel, the first outlet 41 serves as the total outlet for impurity gases, and the second outlet 51 serves as the total outlet for purified hydrogen gases.

[0065] In this embodiment, a palladium-made secondary purification membrane 63 is provided at both ends of the purified hydrogen exhaust channel (i.e., the second channel 62).

[0066] In this embodiment, a gas flow gap is reserved between the inner wall of the housing 2 and the outer surface of the tubular palladium-vanadium / iron-palladium composite membrane 1 to ensure that impurity gases can be fully discharged and to avoid membrane surface blockage or decreased permeation efficiency due to accumulation.

[0067] In this embodiment, the tubular palladium-vanadium / iron-palladium composite membrane 1 is provided with four parallel sections, which are evenly spaced.

[0068] The procedure for using this tubular palladium-vanadium / iron-palladium composite membrane in a purification device for hydrogen purification is as follows: (1) Clean and dry each component of the purification device, remove surface oil and other impurities, weld the tubular palladium-vanadium / iron-palladium composite membrane 1 to the stainless steel shell by argon arc welding, and inspect the weld seam. Then, install it into the cleaned purification device. (2) The secondary purification membrane 63 is fixed at both ends of the second channel 62 by argon arc welding; (3) The purification device is heated to 450°C using an external heating device (conventional technology in the field); (4) A mixture of 98.5% hydrogen gas enters the first chamber 3 through the inlet 31. The pressure difference of the tubular palladium-vanadium / iron-palladium composite membrane 1 is 0.2 MPa. The gas is introduced into the inner side of the tubular palladium-vanadium / iron-palladium composite membrane 1 through the gas supply pipe 7. (5) Under the action of pressure difference and concentration gradient, hydrogen first dissolves on the inner palladium film 12 surface of tubular palladium-vanadium / iron-palladium composite film 1, then diffuses through palladium layer 12 in atomic state, then migrates to the other side through the metal lattice gap of tubular V / Fe alloy substrate 11, and then permeates out of outer palladium film 12. (6) The purified hydrogen is further purified by the secondary purification membrane 63. The second channel 62 serves as the purified hydrogen discharge channel, from which it is discharged in the form of high-purity hydrogen. The second outlet 51 serves as the total outlet of purified hydrogen and is connected to external equipment to output high-purity hydrogen. (7) The impurity gas that has not been permeated is discharged through the first channel 61 (as the impurity gas discharge channel) and the first outlet 41 (as the total outlet of the impurity gas) at the top of the purification device.

[0069] Tests have shown that the hydrogen purification device based on the tubular Pd-V / Fe-Pd composite membrane of this invention can purify 98.5% hydrogen into 99.9994% high-purity hydrogen, with a total hydrogen permeation flux of 6.03 scc / s and a hydrogen recovery rate of 99.5%.

[0070] Example 3 The preparation of a tubular palladium-vanadium / iron-palladium composite film includes the following steps: (1) A tubular V / Fe alloy substrate 11 with a length of 25 cm, a diameter of 0.6 cm, a thickness of 500 μm, and an Fe atomic percentage of 10 at% was chemically activated by sequentially immersing it in a solution with a concentration of 3.0 × 10⁻⁶. -3 A SnCl2 solution with a concentration of 4.0 × 10⁻⁶ mol / L and a SnCl₂ solution with a concentration of 4.0 × 10⁻⁶ mol / L. -4 Sensitization and activation were performed in a mol / L PdCl2 solution with an activation time of 15 min. (2) The tubular V / Fe alloy matrix 11 was cleaned with deionized water and dried with nitrogen to obtain the activated tubular V / Fe alloy matrix 11. (3) A palladium layer 12 is electrolessly plated on the upper and lower surfaces of a tubular V / Fe alloy substrate 11. The substrate is immersed in an electroless plating solution containing 6 g / L PdCl2 and 13 g / L ethylenediamine. The reaction temperature is 50 °C. A 10 mL / L 65 wt% hydrazine hydrate solution is added. The palladium plating reaction on the tubular V / Fe alloy substrate 11 is carried out for 120 min to obtain a tubular palladium-vanadium / iron-palladium composite film 1. The tubular palladium-vanadium / iron-palladium composite film 1 includes a tubular V / Fe alloy substrate 11 and palladium layers 12 formed on the inner and outer surfaces of the tubular V / Fe alloy substrate 1. The wall thickness of the tubular V / Fe alloy substrate 11 is 500 μm. The palladium layer 12 on the inner surface of the tubular V / Fe alloy substrate 12 has a thickness of 4 μm, and the palladium layer 12 on the outer surface of the tubular V / Fe alloy substrate 12 has a thickness of 4 μm.

[0071] like Figure 3 As shown, the tubular palladium-vanadium / iron-palladium composite membrane is used in a purification device. The hydrogen purification device is an external pressure hydrogen purification device, which includes: a shell 2 and a first chamber 3, a second chamber 4, and a third chamber 5 disposed in the shell 2. The first chamber 3 is provided with an air inlet 31, the second chamber 4 is provided with a first air outlet 41, and the third chamber 5 is provided with a second air outlet 51. The third chamber 5 is provided with a plurality of spaced composite membrane storage chambers 6. The composite membrane storage chamber 6 is provided with a tubular palladium-vanadium / iron-palladium composite membrane 1. The two ends of the composite membrane storage chamber 6 are respectively provided with a first channel 61 and a second channel 62. The first channel 61 is connected to the second chamber 4, and the second channel 62 is located in the third chamber 5. The composite membrane storage chamber 6 is connected to the outside of the first chamber 3 via a gas supply pipe 7; When the gas supply pipe 7 is connected to the outside of the tubular palladium-vanadium / iron-palladium composite membrane 1, the hydrogen purification device is an external pressure hydrogen purification device. The first channel 61 serves as the purified hydrogen discharge channel, the second channel 62 serves as the impurity gas discharge channel, the first outlet 41 serves as the purified hydrogen total outlet, and the second outlet 51 serves as the impurity gas total outlet.

[0072] In this embodiment, a secondary purification membrane 63 made of palladium is provided at both ends of the purified hydrogen exhaust channel (i.e., the first channel 61).

[0073] In this embodiment, a gas flow gap is reserved between the inner wall of the housing 2 and the outer surface of the tubular palladium-vanadium / iron-palladium composite membrane 1 to ensure that impurity gases can be fully discharged and to avoid membrane surface blockage or decreased permeation efficiency due to accumulation.

[0074] In this embodiment, the tubular palladium-vanadium / iron-palladium composite membrane 1 is provided with four parallel sections, which are evenly spaced.

[0075] The procedure for using this tubular palladium-vanadium / iron-palladium composite membrane in a purification device for hydrogen purification is as follows: (1) Clean and dry each component of the purification device, remove surface oil and other impurities, weld the tubular palladium-vanadium / iron-palladium composite membrane 1 to the stainless steel shell by argon arc welding, and inspect the weld seam. Then, install it into the cleaned purification device. (2) The secondary purification membrane 63 is fixed at both ends of the first channel 61 by argon arc welding; (3) The purification device is heated to 400°C using an external heating device (conventional technology in the art); (4) A mixture of 99.5% hydrogen gas enters the first chamber 3 through the inlet 31. The pressure difference of the tubular palladium-vanadium / iron-palladium composite membrane 1 is 0.25 MPa. The gas is supplied to the outside of the tubular palladium-vanadium / iron-palladium composite membrane 1 through the gas supply pipe 7. (5) Under the action of pressure difference and concentration gradient, hydrogen first dissolves on the outer palladium film 12 surface of the tubular palladium-vanadium / iron-palladium composite film 1, then diffuses through the palladium layer 12 in atomic state, then migrates to the other side through the metal lattice gap of the tubular V / Fe alloy substrate 11, and then permeates out of the inner palladium film 12. (6) The purified hydrogen is further purified by the secondary purification membrane 63. The first channel 61 serves as the purified hydrogen discharge channel, and the purified hydrogen is discharged in the form of high-purity hydrogen. The first outlet 41 serves as the total outlet of purified hydrogen and is connected to external equipment to output high-purity hydrogen. (7) Unpermeable impurity gases are discharged successively through the second channel 62 (as the impurity gas discharge channel) and the second outlet 51 (as the total impurity gas outlet) at the bottom of the purification device.

[0076] Tests have shown that the hydrogen purification device based on the tubular Pd-V / Fe-Pd composite membrane of this invention can purify 99.5% hydrogen into 99.9997% high-purity hydrogen, with a total hydrogen permeation flux of 71.6 scc / s and a hydrogen recovery rate of 99.6%.

[0077] Example 4 The preparation of a tubular palladium-vanadium / iron-palladium composite film includes the following steps: (1) A tubular V / Fe alloy substrate 11 with a length of 35 cm, a diameter of 0.8 cm, a thickness of 2000 μm, and an Fe atomic percentage of 15 at% was chemically activated by sequentially immersing it in a solution with a concentration of 5.0 × 10⁻⁶. -3 A SnCl2 solution with a concentration of 5.0 × 10⁻⁶ mol / L and a SnCl₂ solution with a concentration of 5.0 × 10⁻⁶ mol / L. -4 Sensitization and activation were performed in a mol / L PdCl2 solution for 20 min. (2) The tubular V / Fe alloy matrix 11 was cleaned with deionized water and dried with nitrogen to obtain the activated tubular V / Fe alloy matrix 11. (3) A palladium layer 12 is electrolessly plated onto the upper and lower surfaces of a tubular V / Fe alloy substrate 11. The substrate is immersed in an electroless plating solution containing 8 g / L PdCl2 and 11 g / L ethylenediamine. The reaction temperature is 45°C, and 8 mL / L 40 wt% hydrazine hydrate solution is added. The palladium plating reaction on the tubular V / Fe alloy substrate 11 is carried out for 180 min to obtain a tubular palladium-vanadium / iron-palladium composite film 1. The tubular palladium-vanadium / iron-palladium composite film 1 includes a tubular V / Fe alloy substrate 11 and palladium layers 12 formed on the inner and outer surfaces of the tubular V / Fe alloy substrate 1. The wall thickness of the tubular V / Fe alloy substrate 11 is 2000 μm. The palladium layer 12 on the inner surface of the tubular V / Fe alloy substrate 12 has a thickness of 6 μm, and the palladium layer 12 on the outer surface of the tubular V / Fe alloy substrate 12 has a thickness of 6 μm.

[0078] The tubular palladium-vanadium / iron-palladium composite membrane is used in a purification device. The hydrogen purification device is an external pressure hydrogen purification device, which includes: a shell 2 and a first chamber 3, a second chamber 4, and a third chamber 5 disposed in the shell 2. The first chamber 3 is provided with an air inlet 31, the second chamber 4 is provided with a first air outlet 41, and the third chamber 5 is provided with a second air outlet 51. The third chamber 5 is provided with a plurality of spaced composite membrane storage chambers 6. The composite membrane storage chamber 6 is provided with a tubular palladium-vanadium / iron-palladium composite membrane 1. The two ends of the composite membrane storage chamber 6 are respectively provided with a first channel 61 and a second channel 62. The first channel 61 is connected to the second chamber 4, and the second channel 62 is located in the third chamber 5. The composite membrane storage chamber 6 is connected to the outside of the first chamber 3 via a gas supply pipe 7; When the gas supply pipe 7 is connected to the outside of the tubular palladium-vanadium / iron-palladium composite membrane 1, the hydrogen purification device is an external pressure hydrogen purification device. The first channel 61 serves as the purified hydrogen discharge channel, the second channel 62 serves as the impurity gas discharge channel, the first outlet 41 serves as the purified hydrogen total outlet, and the second outlet 51 serves as the impurity gas total outlet.

[0079] In this embodiment, a gas flow gap is reserved between the inner wall of the housing 2 and the outer surface of the tubular palladium-vanadium / iron-palladium composite membrane 1 to ensure that impurity gases can be fully discharged and to avoid membrane surface blockage or decreased permeation efficiency due to accumulation.

[0080] In this embodiment, the tubular palladium-vanadium / iron-palladium composite membrane 1 is provided with four parallel sections, which are evenly spaced.

[0081] In this embodiment, a secondary purification membrane 63 made of palladium is provided at both ends of the purified hydrogen exhaust channel (i.e., the first channel 61).

[0082] The procedure for using this tubular palladium-vanadium / iron-palladium composite membrane in a purification device for hydrogen purification is as follows: (1) Clean and dry each component of the purification device, remove surface oil and other impurities, weld the tubular palladium-vanadium / iron-palladium composite membrane 1 to the stainless steel shell by argon arc welding, and inspect the weld seam. Then, install it into the cleaned purification device. (2) The secondary purification membrane 63 is fixed at both ends of the first channel 61 by argon arc welding; (3) The purification device is heated to 450°C using an external heating device (conventional technology in the field); (4) A mixture of 98.5% hydrogen gas enters the first chamber 3 through the inlet 31. The pressure difference of the tubular palladium-vanadium / iron-palladium composite membrane 1 is 0.2 MPa. The gas is supplied to the outside of the tubular palladium-vanadium / iron-palladium composite membrane 1 through the gas supply pipe 7. (5) Under the action of pressure difference and concentration gradient, hydrogen first dissolves on the outer palladium film 12 surface of the tubular palladium-vanadium / iron-palladium composite film 1, then diffuses through the palladium layer 12 in atomic state, then migrates to the other side through the metal lattice gap of the tubular V / Fe alloy substrate 11, and then permeates out of the inner palladium film 12. (6) The purified hydrogen is further purified by the secondary purification membrane 63. The first channel 61 serves as the purified hydrogen discharge channel, and the purified hydrogen is discharged in the form of high-purity hydrogen. The first outlet 41 serves as the total outlet of purified hydrogen and is connected to external equipment to output high-purity hydrogen. (7) Unpermeable impurity gases are discharged successively through the second channel 62 (as the impurity gas discharge channel) and the second outlet 51 (as the total impurity gas outlet) at the bottom of the purification device.

[0083] Tests have shown that the hydrogen purification device based on the tubular Pd-V / Fe-Pd composite membrane of this invention can purify 98.5% hydrogen into 99.9994% high-purity hydrogen, with a total hydrogen permeation flux of 12.06 scc / s and a hydrogen recovery rate of 99.5%.

[0084] Although the present invention has been described in detail above with general descriptions, specific embodiments, and experiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A tubular palladium-vanadium / iron-palladium composite membrane, characterized in that, The tubular palladium-vanadium / iron-palladium composite film (1) includes: a tubular V / Fe alloy substrate (11) and palladium layers (12) formed on the inner and outer surfaces of the tubular V / Fe alloy substrate (11).

2. The tubular palladium-vanadium / iron-palladium composite membrane according to claim 1, characterized in that, In the tubular V / Fe alloy matrix (11), the atomic percentage content of Fe is 5 at% to 30 at%.

3. The tubular palladium-vanadium / iron-palladium composite membrane according to claim 1, characterized in that, The wall thickness of the tubular V / Fe alloy matrix (11) is 150~500μm; The thickness of the palladium layer (12) on the inner and outer surfaces is 2~10 μm, respectively.

4. A method for preparing a tubular palladium-vanadium / iron-palladium composite film according to any one of claims 1 to 3, characterized in that, The tubular V / Fe alloy substrate (11) was sequentially immersed in tin salt solution and first palladium salt solution for sensitization and activation treatment, cleaned, dried and then immersed in second palladium salt-ethylenediamine chemical plating solution. Hydrazine hydrate solution was added to react, and the palladium layer (12) was formed on the inner and outer surfaces of the tubular V / Fe alloy substrate (11) by chemical plating to obtain a tubular palladium-vanadium / iron-palladium composite film.

5. The method for preparing a tubular palladium-vanadium / iron-palladium composite film according to claim 4, characterized in that, The tin salt solution includes one or more of stannous chloride, stannous bromide, stannous iodide, stannous sulfate, and stannous methanesulfonate solution; The first palladium salt solution and the second palladium chloride solution are each independently one or more of the following: palladium chloride solution, palladium bromide solution, palladium iodide solution, palladium nitrate solution, and palladium acetate solution. The concentration of the tin salt solution is 2.0 × 10⁻⁶. -3 ~6.0×10 -3 mol / L; The concentration of the first palladium salt solution is 3.0 × 10⁻⁶. -4 ~6.0×10 -4 mol / L; The concentration of the second palladium salt in the second palladium salt-ethylenediamine electroless plating solution is 4~8 g / L, and the concentration of ethylenediamine is 10~15 g / L; The concentration of the hydrazine hydrate solution is 30 wt% ~ 90 wt%; The volume ratio of the hydrazine hydrate solution to the second palladium salt-ethylenediamine electroless plating solution is 4~12mL:1L; The reaction is carried out at a temperature of 40-60°C for 1-3 hours.

6. The application of the tubular palladium-vanadium / iron-palladium composite membrane as described in any one of claims 1 to 3, characterized in that, The tubular palladium-vanadium / iron-palladium composite membrane is used to purify hydrogen from a hydrogen-containing gas mixture.

7. The application of the tubular palladium-vanadium / iron-palladium composite membrane according to claim 6, characterized in that, The tubular palladium-vanadium / iron-palladium composite membrane is used to prepare a hydrogen purification device. The hydrogen purification device includes a shell (2) and a first chamber (3), a second chamber (4), and a third chamber (5) disposed in the shell (2). The first chamber (3) is provided with an air inlet (31), the second chamber (4) is provided with a first air outlet (41), and the third chamber (5) is provided with a second air outlet (51). The third chamber (5) is provided with a plurality of spaced composite membrane storage chambers (6), and a tubular palladium-vanadium / iron-palladium composite membrane (1) is provided in the composite membrane storage chamber (6). A first channel (61) and a second channel (62) are respectively provided at both ends of the composite membrane storage chamber (6). The first channel (61) is connected to the second chamber (4), and the second channel (62) is located in the third chamber (5). The composite membrane storage chamber (6) is connected to the first chamber (3) via a gas supply pipe (7).

8. The application of the tubular palladium-vanadium / iron-palladium composite membrane according to claim 7, characterized in that, The gas supply pipe (7) is connected to the inner or outer side of the tubular palladium-vanadium / iron-palladium composite membrane (1); When the gas supply pipe (7) is connected to the inner side of the tubular palladium-vanadium / iron-palladium composite membrane (1), the hydrogen purification device is an internal pressure hydrogen purification device, the first channel (61) serves as the impurity gas discharge channel, the second channel (62) serves as the purified hydrogen discharge channel, the first outlet (41) serves as the total outlet of the impurity gas, and the second outlet (51) serves as the total outlet of the purified hydrogen. When the gas supply pipe (7) is connected to the outside of the tubular palladium-vanadium / iron-palladium composite membrane (1), the hydrogen purification device is an external pressure hydrogen purification device. The first channel (61) serves as the purified hydrogen discharge channel, the second channel (62) serves as the impurity gas discharge channel, the first outlet (41) serves as the purified hydrogen total outlet, and the second outlet (51) serves as the impurity gas total outlet.

9. The application of the tubular palladium-vanadium / iron-palladium composite membrane according to claim 8, characterized in that, The purified hydrogen discharge channel is also provided with secondary purification membranes (63) made of palladium or its alloy at both ends.

10. The application of the tubular palladium-vanadium / iron-palladium composite membrane according to claim 7, characterized in that, The operation process of the hydrogen purification device is as follows: S1. Introduce raw material gas: Introduce hydrogen-containing mixed gas into the first chamber (3) through the gas inlet (31) and transport it to the feed side of the tubular palladium-vanadium / iron-palladium composite membrane (1) through the gas supply pipe (7); S2, Hydrogen separation and purification: Under the conditions of operating temperature of 350℃~650℃, operating pressure of 100Pa~1.2MPa, and pressure difference on both sides of the composite membrane (1) ≤0.3MPa, hydrogen selectively permeates through the composite membrane (1) to its permeation side under the drive of pressure difference and concentration gradient. S3. Product Output: The purified hydrogen from the permeation side is collected through the corresponding purified hydrogen discharge channel and output from the total purified hydrogen outlet; the impurity gas that has not permeated is collected through the corresponding impurity gas discharge channel and output from the total impurity gas outlet.

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