Palladium-based alloy material, method for preparing the same, and use thereof

Abstract

The application relates to the field of palladium-based alloy materials, and discloses a palladium-based alloy material and a preparation method and application thereof, wherein the palladium-based alloy material contains Pd, Cu and Ni, and the molar ratio of Pd, Cu and Ni is 100:(65-93):(37-62); the crystal structure of the palladium-based alloy material is body-centered cubic packing, the lattice parameter k is 0.2703-0.2911 nm, and the half-peak width of at least one characteristic peak in the XRD spectrum of the palladium-based alloy material in the range of 20-90 degrees is less than or equal to 0.1396. The palladium-based alloy material with the body-centered cubic packing crystal structure can not only improve the purity of hydrogen, but also improve the hydrogen recovery rate.

Description

Technical Field

[0001] This invention relates to the field of palladium-based alloy materials, specifically to a palladium-based alloy material, its preparation method, and its applications. Background Technology

[0002] Hydrogen energy is considered the most promising clean energy source in the 21st century, possessing several highly competitive characteristics: (1) high energy density, with a calorific value per unit mass approximately 4 times that of coal, 3.1 times that of gasoline, and 2.6 times that of natural gas; (2) storable and carbon-free, allowing for flexible use across time and regions compared to electricity. Therefore, hydrogen is the best energy carrier in the global energy transition process. Hydrogen energy is playing an increasingly important role in the chemical industry, food, semiconductor industry, communication base stations, low-temperature superconductivity, military, and aviation fields. The World Hydrogen Energy Association predicts that by 2050, 20% of global carbon dioxide emission reductions can be achieved through hydrogen energy. The effective use of hydrogen energy will help improve the global energy structure and mitigate the greenhouse effect. The global production of "pure hydrogen" is approximately 80 million tons per year, mainly from: 76% natural gas reforming, 23% coal-based hydrogen production, and 1% water electrolysis. Currently, industrial hydrogen production is mainly based on "gray hydrogen" produced from carbon-based fossil energy and "blue hydrogen" produced using carbon-based energy supplemented by carbon dioxide capture, utilization, and storage technologies. The production of "green hydrogen" using renewable energy and nuclear power through water electrolysis, achieving a 100% green and carbon-free process, still faces technological challenges. However, the development of "green hydrogen" will be the future trend of hydrogen energy production. Utilizing renewable energy for water electrolysis to produce hydrogen is a flexible, efficient, and low-cost "green hydrogen" solution. It can be vigorously developed in areas with abundant wind and solar power resources. However, the uneven distribution of renewable energy in time and space is a significant factor restricting its rapid development. Meanwhile, the purity of the produced hydrogen is not high (usually less than 95%). To meet the industrial demand for various high-purity hydrogens, hydrogen must be separated and purified. Common hydrogen separation methods include cryogenic separation, pressure swing adsorption (PSA), and membrane separation. Among these, membrane separation has advantages such as small size, simple operation, and low noise, making it particularly suitable for small- to medium-scale applications requiring high hydrogen purity. However, the reaction temperature for hydrogen production by water electrolysis is relatively low, usually below 100℃. Conventional pure palladium membranes are difficult to adapt to this operating condition. When the temperature is <200℃, the pure palladium membrane is prone to hydrogen embrittlement and cracking due to drastic changes in lattice parameters after hydrogen dissolves, which greatly reduces the quality of hydrogen separated by the palladium membrane. Summary of the Invention

[0003] The purpose of this invention is to overcome the problems existing in the prior art and to provide a palladium-based alloy material, its preparation method, and its application.

[0004] To achieve the above objectives, the first aspect of the present invention provides a palladium-based alloy material containing Pd, Cu, and Ni, wherein the molar ratio of Pd, Cu, and Ni is 100:(65-93):(37-62), the palladium-based alloy material has a body-centered cubic crystal structure, a lattice parameter k of 0.2703-0.2911 nm, and the full width at half maximum (FWHM) of at least one characteristic peak of 2θ in the range of 20°-90° in the XRD pattern of the palladium-based alloy material is less than or equal to 0.1396.

[0005] The second aspect of the present invention provides a method for preparing palladium-based alloy materials, the method comprising: depositing Pd, Cu and Ni on a support, and then alloying the support on which Pd, Cu and Ni have been deposited, wherein the molar ratio of Pd, Cu and Ni is 100:(65-93):(37-62).

[0006] The alloying treatment is carried out as follows: after treatment in an activating atmosphere at a temperature of 500-550℃ and a pressure of 0.43-0.56MPa for 5-8 hours, the temperature is reduced to 100-160℃ at a rate of 50-70℃ / min. The gases providing the activating atmosphere include H2, N2 and NH3, and the volume ratio of H2, N2 and NH3 is 100:(21-64):(1-13).

[0007] A third aspect of the present invention provides a palladium-based alloy material prepared by the method described above.

[0008] The fourth aspect of this invention provides the application of the palladium-based alloy material described above in hydrogen separation.

[0009] The palladium-based alloy material of the present invention, with a body-centered cubic stacked crystal structure, can not only improve the purity of hydrogen to obtain high-purity hydrogen (greater than 99.9999%), but also improve the hydrogen recovery rate, making the recovery rate of high-purity hydrogen higher than 99%. Simultaneously, the palladium-based alloy material of the present invention can avoid hydrogen embrittlement and cracking caused by hydrogen dissolution in the palladium film. The palladium-based alloy material of the present invention can operate stably for a long time while ensuring hydrogen purity and recovery rate. Attached Figure Description

[0010] Figure 1 The image shows a scanning electron microscope (SEM) image of the palladium-based alloy material in Example G1. Detailed Implementation

[0011] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0012] The first aspect of the present invention provides a palladium-based alloy material containing Pd, Cu, and Ni, wherein the molar ratio of Pd, Cu, and Ni is 100:(65-93):(37-62), the palladium-based alloy material has a body-centered cubic crystal structure, the lattice parameter k is 0.2703-0.2911 nm, and the full width at half maximum (FWHM) of at least one characteristic peak of 2θ in the range of 20°-90° in the XRD pattern of the palladium-based alloy material is less than or equal to 0.1396.

[0013] In this invention, "body-centered cubic packing" refers to a close-packed arrangement in a cubic crystal system, which includes two lattice points, one at the vertex and one at the body center. That is, eight atoms are located at the eight vertices of the cube, and one atom is located at the center of the cube. The eight atoms at the vertices are tangent to the central atom.

[0014] In this invention, "lattice parameter k" refers to the physical dimensions of a unit cell in a crystal lattice, representing a fundamental structural parameter of a crystalline material. The lattice parameter k represents the edge length of the unit cell, that is, the edge length of each parallelepiped unit, and it is directly related to the bonding energy between atoms. A unit cell in three-dimensional space generally has three lattice parameters, denoted by a, b, and c. Based on the morphological distribution of the Bravais lattice, in the cubic crystal structure (body-centered cubic packing) involved in this invention, these three constants are all equal, and therefore can be represented by parameter k. Changes in k reflect changes in the composition, stress state, etc., within the crystal. The lattice parameter k can be determined using X-ray diffraction (XRD) or atomic force microscopy (AFM).

[0015] According to the present invention, preferably, the full width at half maximum (FWHM) of all characteristic peaks of 2θ in the range of 20°-90° in the XRD pattern of the palladium-based alloy material is less than or equal to 0.1396, more preferably less than or equal to 0.0513, and usually greater than or equal to 0.0175.

[0016] According to the present invention, preferably, in the XRD pattern of the palladium-based alloy material, the full width at half maximum (FWHM) of the characteristic peak at 2θ = 43° ± 1° (i.e., the characteristic peak of crystal plane (110)) is less than or equal to 0.0524 (e.g., 0.0524, 0.05, 0.045, 0.04, 0.035, 0.03, 0.025, 0.02, 0.0175, 0.015, 0.01, and any two of the above points), more preferably 0.0175-0.0258, or the characteristic peak at 2θ = 53° ± 1° (i.e., the characteristic peak of crystal plane (111)). The full width at half maximum (FWHM) of the characteristic peak at 2θ = 62° ± 1° (i.e., 0.0698, 0.06, 0.0524, 0.05, 0.045, 0.04, 0.035, 0.03, 0.025, 0.02, 0.015, 0.01, and any two of the above points) is less than or equal to 0.0698 (e.g., 0.0698, 0.06, 0.0524, 0.05, 0.045, 0.035, 0.03, 0.025, 0.02, 0.015, 0.01, and any two of the above points), more preferably 0.02-0.041, or the FWHM of the characteristic peak at 2θ = 62° ± 1° (i.e., the characteristic peak of the crystal plane (200)) is less than or equal to 0.0698 (e.g., 0.0698, 0.06, 0.0524, 0.05, 0.045, 0.01, and any two of the above points). The range of 0.04, 0.035, 0.03, 0.025, 0.02, 0.015, 0.01, and any two of the above points), more preferably 0.046-0.056, or the full width at half maximum (FWHM) of the characteristic peak at 2θ = 70° ± 1° (i.e., the characteristic peak of the crystal plane (210)) is less than or equal to 0.1047 (e.g., 0.1047, 0.09, 0.08, 0.07, 0.06, 0.0524, 0.05, 0.045, 0.04, 0.035, 0.03, 0.025, 0.02, 0.015, 0.045 ...5, 0.035, 0.03, 0.025, 0.02, 0.015, 0.045, 0.0524, 0.05, 0.0524, 0.05, 0.045, 0.045, 0.035, 0.03, 0.025, 0.02, 0.015, 0.0524, 0.0524, 0.05, 0.045, 0.045, 0.035, 0.03, 0.025, 0.02, 01, and the range formed by any two points mentioned above), more preferably 0.06-0.072, or the half-width of the characteristic peak at 2θ=79°±1° (i.e., the characteristic peak of the crystal plane (211)) is less than or equal to 0.1396 (e.g., 0.1571, 0.1, 0.09, 0.08, 0.07, 0.06, 0.0524, 0.05, 0.045, 0.04, 0.035, 0.03, 0.025, 0.02, 0.015, 0.01, and the range formed by any two points mentioned above), more preferably 0.07-0.086. The "half-width" is defined as the peak width at half the peak height, i.e., the half-height width. The half-height width is converted into radians according to the Debye-Scherrer formula (D=Kγ / Bcosθ), and the radian value characterizes the size of the half-width. When the palladium-based alloy material has no characteristic peak at the corresponding 2θ, the half-peak width is considered to be 0.

[0017] According to the present invention, preferably, the thickness of the palladium-based alloy material is 0.5-30 μm (e.g., 0.5 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, and any two of the above), more preferably 5-15 μm, and even more preferably 7.5-8.5 μm.

[0018] According to the present invention, preferably, the palladium-based alloy material is a film material.

[0019] According to the present invention, preferably, the palladium-based alloy material is attached to a support, and the thickness of the support is 0.1-20 mm (for example, 0.1 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 15 mm, 20 mm, and any two of the above), more preferably 2-5 mm.

[0020] The second aspect of the present invention provides a method for preparing palladium-based alloy materials, the method comprising: depositing Pd, Cu and Ni on a support, and then alloying the support on which Pd, Cu and Ni have been deposited, wherein the molar ratio of Pd, Cu and Ni is 100:(65-93):(37-62).

[0021] The alloying treatment is performed as follows: the material is treated in an activating atmosphere at a temperature of 500-550℃ and a pressure of 0.43-0.56 MPa for 5-8 hours; then the temperature is reduced to 100-160℃ at a rate of 50-70℃ / min. The activating atmosphere consists of gases including H2, N2, and NH3, with a volume ratio of H2, N2, and NH3 of 100:(21-64):(1-13). The palladium-based alloy material obtained according to this preferred embodiment exhibits higher hydrogen permeability or stability (smaller half-width at half-maximum corresponding to characteristic peaks). The addition of alkaline gas NH3 enables faster activation of the palladium-based alloy film, resulting in a more stable body-centered cubic structure and a smaller half-width at half-maximum for the characteristic peaks in the XRD pattern.

[0022] In this invention, the pressure of the alloying process is generally controlled by adjusting the amount of gas used to provide the activating atmosphere. After being cooled to below 160°C at a specific rate, it can be cooled to room temperature for later use.

[0023] According to the present invention, preferably, the total thickness of Pd, Cu and Ni deposited on the support is 0.5-30 μm (e.g., 0.5 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, and any two of the above), more preferably 5-15 μm, and even more preferably 7.5-8.5 μm.

[0024] According to the present invention, preferably, the thickness of the support is 0.1-20 mm (e.g., 0.1 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 15 mm, 20 mm, and any two of the above), more preferably 2-5 mm. The support can be provided by materials commonly used in the art that can withstand the operating temperature of the present invention without affecting hydrogen permeability, that is, materials that do not deform or affect hydrogen permeability at the operating temperature of the present invention. While ensuring excellent hydrogen permeability, in order to obtain better mechanical and thermal stability and reduce the amount of palladium used (reducing costs), preferably, the support is a porous support, which can be selected from at least one of porous ceramics, porous glass, porous metals (such as porous stainless steel), porous quartz, and polymers, more preferably from at least one of porous ceramics, porous metals, and polymers. Generally, the porosity distribution of the support ranges from 15-75%, and the average pore size is 0.05-0.4 μm. To obtain a tubular membrane, the support is preferably a tubular support. The porous ceramic material can be γ-Al₂O₃, with a porosity distribution ranging from 25-66% and an average pore size of 0.12-0.4 μm. The porous stainless steel material can be 316L(Fe₂O₃). 69 Cr 17 Ni 12 Mo2 has a porosity ranging from 32% to 71% and an average pore size of 0.08 to 0.36 μm. The polymer material can be polyimide, with a porosity ranging from 15% to 37% and an average pore size of 0.05 to 0.22 μm. The "porosity range" and "average pore size" can both be determined using nitrogen physical adsorption.

[0025] A third aspect of the present invention provides a palladium-based alloy material prepared by the method described above.

[0026] The present invention reduces the hydrogen permeation activation energy of the membrane material (palladium-based alloy material) by performing heat treatment at a specific temperature and then cooling it at a specific rate, thereby improving the hydrogen permeation efficiency and stability of the membrane material (the half-peak width corresponding to the characteristic peak is small). The use of ammonia will further improve the hydrogen permeability and stability of the membrane material.

[0027] The fourth aspect of this invention provides the application of the palladium-based alloy material described above in hydrogen separation.

[0028] According to the present invention, preferably, the conditions for separating hydrogen include: a transmembrane pressure difference greater than or equal to 0.1 MPa (e.g., 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, 1 MPa, 10 MPa, and any two of the above), preferably 0.3-0.5 MPa; and a system separation temperature of 373-473 K (e.g., 373 K, 380 K, 390 K, 400 K, 410 K, 420 K, 430 K, 440 K, 473 K, and any two of the above), preferably 380-423 K. The transmembrane pressure difference refers to the difference between the pressure on the inner side of the membrane (the side where the feed gas enters) and the pressure on the outer side (the side where hydrogen permeates out). The purity of hydrogen in the sample to be separated can be less than or equal to 99.9% by volume (e.g., 99-99.9% by volume).

[0029] The present invention will be described in detail below through embodiments. In the following embodiments, the inner surface of the support is sealed with polytetrafluoroethylene (PTFE) material, and therefore the PTFE material is peeled off before application or performance testing.

[0030] Examples G1-G3

[0031] Using a porous stainless steel tube as the support (tubular, inner diameter: 9.5 mm, outer diameter: 12.5 mm; average pore size: 0.25 μm, porosity: 65%), the support was first soaked in anhydrous ethanol for 30 minutes to remove surface contaminants such as dust and grease. Then, the surface and inner side of the support were rinsed with deionized water and placed in warm water for vacuum rinsing to remove residual ethanol from the pores. Finally, it was placed in an oven and dried at 423 K for 4 hours. Pd, Cu, and Ni were deposited on the support using electroplating according to Faraday's law. The molar ratio M of Pd, Cu, and Ni is shown in Table 1. The effective film area was 21 cm². 2 The electroplating conditions were as follows: using a conductive layer carrier as the working electrode, a platinum electrode (Pd plated), a waveguide with a copper content of 99.999% (Cu plated), and a nickel electrode (Ni plated) as the counter electrodes, and a saturated calomel electrode as the reference electrode, at a temperature of 30°C, the metal ions (Pd) in the plating bath... 2+ Cu 2+ Ni 2+The concentration was 0.01-0.3 mol / L. Electroplating experiments were carried out using cyclic voltammetry, with the working voltage range being -0.60V to -0.90V, the scan rate being 0.0075V / s, the scan period being 1000, and the sensitivity being set to 0.0001A / V. Meanwhile, during the electroplating process, a plunger-type constant flow pump was used to add the following solutions to the plating bath at a rate of 1-2 ml / min: 0.05 mol / L ammonium palladium chloride ((NH4)2PdCl4) solution; 0.5-1.5 ml / min: 0.075 mol / L copper nitrate (Cu(NO3)2) solution; 0.2-1.0 ml / min: 0.05 mol / L nickel sulfate (NiSO4) solution; 0.05-0.12 ml / min: ethylenediamine (EDA, 99%, analytical grade); 0.025-0.05 ml / min: disodium ethylenediaminetetraacetate (EDTA-2Na, 99%, analytical grade); and 0.01-0.015 ml / min: bipyridine (C... 10 H8N2 (99%, analytical grade). The plating bath was vigorously stirred (1000 r / min) while the above solution was added. Every 30 min of electroplating, the working electrode, cleaned with distilled water, was immersed for 10 min in 0.05 mol / L phosphoric acid (H3PO4) solution and 0.05 mol / L dipotassium hydrogen phosphate (K2HPO4) solution, respectively. After the cyclic voltammetry procedure, the working electrode was treated in distilled water at 100℃ for 10 min before being removed. The Pd, Cu, and Ni deposited support was subjected to high-temperature alloying treatment. The alloying treatment was performed as follows: under an activating atmosphere, at temperature T1 and pressure P, the temperature was lowered to T2 at a rate V. The activating atmosphere consisted of H2, N2, and NH3, with the volume ratio of H2, N2, and NH3 equal to R1. The amount of activating atmosphere gas provided ensured that the alloying pressure was P. Detailed parameters are shown in Table 1.

[0032] Table 1

[0033]

[0034]

[0035] Comparative example GD1

[0036] The process is carried out in accordance with Example G1, except that the gas providing the activating atmosphere is only N2.

[0037] Comparative example GD2

[0038] The process is carried out in accordance with Example G1, except that the gas providing the activating atmosphere is only H2.

[0039] Comparative example GD3

[0040] The process is carried out in accordance with Example G1, except that the gas providing the activation atmosphere is only argon.

[0041] Comparative example GD4

[0042] The process is carried out in accordance with Example G1, except that the gases providing the activation atmosphere are hydrogen and CO2 (volume ratio of 1:1).

[0043] Comparative example GD5

[0044] The process was carried out in accordance with Example G1, except that the temperature was reduced to T2 at a rate of V = 5°C / min.

[0045] Comparative example GD6

[0046] The process was carried out in accordance with Example G1, except that the alloying temperature T1 = 700°C.

[0047] Comparative example GD7

[0048] The process was carried out in accordance with Example G1, except that the alloying pressure P = 0.1 MPa.

[0049] Comparative example GD8

[0050] The procedure was carried out in accordance with Example G1, except that the molar ratio of Pd, Cu and Ni was 100:500:500.

[0051] Comparative example GD9

[0052] The procedure was carried out in accordance with Example G1, except that the molar ratio of Pd, Cu and Ni was 100:0.5:0.5.

[0053] Test case

[0054] (I) The materials obtained after alloying treatment in each embodiment and comparative example (i.e., palladium-based alloy materials) were characterized. The characterization method is as follows, and the crystal structure parameters of the palladium-based alloy materials are shown in Table 2.

[0055] The crystal structure analysis of palladium-based alloy materials was performed on an X'Pert PRO / PANalytical automated X-ray diffractometer manufactured by Philips, Netherlands. The experimental conditions were Cu K α X-rays (λ = 0.1543 nm), tube voltage 40 kV, current 40 mA, diffraction angle 2θ scan range 10-90°. The interplanar spacing of the sample was calculated using the Bragg equation.

[0056] d=λ / 2sinθ

[0057] Where λ corresponds to Cu K α The wavelength of the radiation, θ is the angle of the diffraction peak.

[0058] The crystal structure of the palladium-based alloy was tested at the European Synchrotron Radiation Facility (beam BM25A) in France, which has higher resolution, with synchrotron radiation λ = 0.0618886 nm or 0.077449 ​​nm and tube voltage of 10.0335 keV or 20.0335 keV. Initially, a 10 × 1 mm sample was used. 2 The sample was placed in a 2mm diameter quartz capillary tube, with both ends sealed with quartz wool. The capillary tube was then mounted on a rotating sample stage (to ensure uniform temperature and a larger X-ray irradiation area). The test temperature range was 298-473K (heated by a hot air blower), and the pressure range was 10... -4 The test atmosphere was -130 kPa. Hydrogen gas was first introduced and treated for 30 minutes, then a vacuum was drawn, and helium gas was introduced as a protective gas for measurement.

[0059] Methods for testing the lattice parameters of palladium-based alloy materials: Combining the above in-situ XRD tests, the cell parameters of the palladium-based alloy materials are obtained (represented by three cell constants a, b, and c, and the three inter-edge angles α, β, and γ). According to the formula d1 = a / (α... 2 +β 2 +γ 2 ) 0.5 d2=b / (α) 2 +β 2 +γ 2 ) 0.5 d3=c / (α) 2 +β 2 +γ 2 ) 0.5The interplanar spacing (d1 d2 d3) of the corresponding characteristic crystal planes is calculated. That is, the PdCuNi alloy material obtained in this invention belongs to the body-centered cubic (BCC) structure, and its characteristic crystal planes include (110), (111), (200), (210), and (211). At the same time, according to the X-ray diffraction results, a series of different characteristic crystal plane ratios (the intensity corresponding to different crystal planes) can be obtained. For example, in the PdCuNi alloy material obtained in this invention, the (110) plane corresponds to the characteristic peak at 2θ = 43° ± 1°, the (111) plane corresponds to the characteristic peak at 2θ = 53° ± 1°, the (200) plane corresponds to the characteristic peak at 2θ = 62° ± 1°, the (210) plane corresponds to the characteristic peak at 2θ = 70° ± 1°, and the (211) plane corresponds to the characteristic peak at 2θ = 79° ± 1°. Using HighScorePlus analysis software, combined with the peak intensities of the aforementioned characteristic crystal planes, the lattice parameters k of the corresponding materials are calculated.

[0060] The thickness of the palladium-based alloy material was tested using a scanning electron microscope (SEM) (model: JSM-7610F). The thickness of the alloy film was determined by measuring the corresponding scale according to the magnification. The surface smoothness of the obtained palladium-based alloy material could also be observed using the SEM. The surface smoothness of the palladium-based alloy material in Example G1 is shown below. Figure 1 As shown in the figure, the palladium-based alloy material obtained by the method of the present invention has a uniform structure and a smooth surface. The surface smoothness of the palladium-based alloy materials in Examples G2-G3 is similar to that of the palladium-based alloy material in Example G1, and will not be shown here again.

[0061] The method for testing the half-peak width (WHM) of palladium-based alloy materials is as follows: based on the XRD spectrum test results, combined with HighScorePlus software analysis, the radian value of the WHM is obtained.

[0062] E act (Hydrogen permeation activation energy, unit: kJ·mol) -1 The test method involves measuring the hydrogen permeation rate from 573 K to 773 K under a transmembrane pressure difference of 0.1 MPa, combined with the Arrhenius equation J. H2 =J H2 ° exp(-E act / RT), calculated through measurement, where J H2 It is the hydrogen permeation diffusion rate, J H2 ° is the hydrogen permeation diffusion coefficient, R is the gas constant, and T is the absolute temperature. The higher the hydrogen permeation activation energy, the higher the hydrogen mass transfer resistance of the composite membrane material, and the more difficult it is for hydrogen to permeate and diffuse through the composite membrane.

[0063] J H2 (Hydrogen permeation rate, unit: mol·m)-2 ·s -1 The test method involves measuring the volume of hydrogen passing through the palladium-based composite membrane per minute (liters) at 20℃ and a transmembrane pressure difference of 0.1 MPa, and then normalizing it to the hydrogen permeation rate (mol·m²) based on the membrane area (square meters). -2 ·s -1 ).

[0064] J N2 (Nitrogen permeation diffusion rate, unit: mmol·m) -2 ·s -1 The test method involves measuring the volume (mL) of nitrogen gas passing through the palladium-based composite membrane per minute at 20℃ and a transmembrane pressure difference of 0.1 MPa, and then normalizing it to the hydrogen permeation rate (mmol·m²) based on the membrane area (m²). -2 ·s -1 ).

[0065] Table 2

[0066]

[0067] Note: BCC+FCC in Table 2 indicates that it includes both body-centered cubic packing and face-centered cubic close packing.

[0068] (II) Performance Testing

[0069] The performance of the composite membranes prepared in the above embodiments and comparative examples in the preparation of high-purity hydrogen was tested.

[0070] The composite membrane prepared above was encapsulated in a tubular reactor. Nitrogen gas was first introduced into the inner and outer sides of the composite membrane at flow rates of 10 mL / min and 30 mL / min, respectively. The temperature was increased to 623 K at a rate of 1 K / min, and the composite membrane was activated for 5 hours. Then, hydrogen gas (99.0% purity) produced by water electrolysis was introduced into the tubular reactor. High-purity hydrogen gas was obtained under the separation action of the composite membrane. The separation temperature was controlled at 423 K, and the pressure difference between the inside and outside of the composite membrane (P) was maintained. 外侧 -P 内侧 The pressure is equal to 0.5 MPa. The gas components to be separated, high-purity hydrogen, and residual components during the separation process were analyzed online using a Shanghai Tianmei SCION-456 gas chromatograph equipped with FID and PDHID detectors. Product distribution and hydrogen purity changes were monitored in real time, and the purity of high-purity hydrogen was calculated based on the detection results. High-purity hydrogen was tested every 5 hours. The continuous operating time was recorded when the purity of high-purity hydrogen decreased to 99.999%. The initial separation values ​​and experimental measurements after reaching the continuous operating time are shown in Table 3. The purity of high-purity hydrogen is represented by S. 高 The hydrogen recovery rate is expressed in H2. 回 It means that H 回The calculation formula is: H 回 = Amount of hydrogen on the permeate side / (Amount of hydrogen on the permeate side + Amount of hydrogen on the residual permeate side).

[0071] Table 3

[0072]

[0073] As shown in Table 3, the palladium-based alloy material with a body-centered cubic stacked crystal structure of the present invention can not only improve the purity of hydrogen and obtain high-purity (greater than 99.9999%) hydrogen, but also improve the recovery rate of hydrogen, making the recovery rate of high-purity hydrogen higher than 99%. At the same time, the palladium-based alloy material of the present invention can also avoid hydrogen embrittlement and cracking caused by hydrogen dissolution of the palladium film.

[0074] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A palladium-based alloy material, characterized in that, This palladium-based alloy material contains Pd, Cu, and Ni, with a molar ratio of Pd, Cu, and Ni of 100:(65-93):(37-62). The palladium-based alloy material has a body-centered cubic crystal structure with a lattice parameter k of 0.2703-0.2911 nm. In the XRD pattern of this palladium-based alloy material, 2θ is at 20 nm. o -90 o The full width at half maximum (FWHM) of at least one characteristic peak within the range is less than or equal to 0.1396.

2. The palladium-based alloy material according to claim 1, wherein, In the XRD pattern of the palladium-based alloy material, 2θ is at 20°. o -90 o The full width at half maximum (FWHM) of all characteristic peaks within the range is less than or equal to 0.1396.

3. The palladium-based alloy material according to claim 1 or 2, wherein, In the XRD pattern of the palladium-based alloy material, 2θ = 43. o ±1 o The full width at half maximum (FWHM) of the characteristic peak at that location is less than or equal to 0.0524, or 2θ = 53. o ±1 o The full width at half maximum (FWHM) of the characteristic peak at that location is less than or equal to 0.0698, or 2θ = 62. o ±1 o The full width at half maximum (FWHM) of the characteristic peak at that location is less than or equal to 0.0698, or 2θ = 70°. o ±1 o The full width at half maximum (FWHM) of the characteristic peak at that location is less than or equal to 0.1047, or 2θ = 79. o ±1 o The full width at half maximum (FWHM) of the characteristic peak at that location is less than or equal to 0.1396. And / or, the thickness of the palladium-based alloy material is 0.5-30µm.

4. The palladium-based alloy material according to claim 1 or 2, wherein, The thickness of the palladium-based alloy material is 5-15µm.

5. The palladium-based alloy material according to claim 1 or 2, wherein, The palladium-based alloy material is a film-like material.

6. The palladium-based alloy material according to claim 1 or 2, wherein, The palladium-based alloy material is attached to the support, and the thickness of the support is 0.1-20 mm.

7. The palladium-based alloy material according to claim 1 or 2, wherein, The palladium-based alloy material is attached to the support, and the thickness of the support is 2-5 mm.

8. A method for preparing palladium-based alloy materials, characterized in that, The method includes: depositing Pd, Cu and Ni on a support, and then alloying the support with deposited Pd, Cu and Ni, wherein the molar ratio of Pd, Cu and Ni is 100:(65-93):(37-62); The alloying process is as follows: after treatment in an activating atmosphere at a temperature of 500-550℃ and a pressure of 0.43-0.56MPa for 5-8 hours, the temperature is reduced to 100-160℃ at a rate of 50-70℃ / min. The gases providing the activating atmosphere include H2, N2 and NH3, and the volume ratio of H2, N2 and NH3 is 100:(21-64):(1-13).

9. The method according to claim 8, wherein, The total thickness of Pd, Cu and Ni deposited on the support is 0.5-30µm.

10. The method according to claim 8, wherein, The total thickness of Pd, Cu and Ni deposited on the support is 5-15µm.

11. The method according to claim 8, wherein, The thickness of the support is 0.1-20mm.

12. The method according to claim 8, wherein, The thickness of the support is 2-5mm.

13. The palladium-based alloy material prepared by the method according to any one of claims 8-12.

14. The use of the palladium-based alloy material according to any one of claims 1-7 and 13 in hydrogen separation.

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