Palladium-based composite alloy material, its manufacturing method and use

Abstract

The present invention relates to a palladium-based composite alloy material, its manufacturing method, and its use. The palladium-based composite alloy material contains Pd and a Group IB metal element, and in the XRD spectrum of the palladium-based composite alloy material, the half-width of at least one characteristic peak within the 2θ range of 5° to 90° is 0.1745 or less. The palladium-based composite alloy material used in the present invention has a low hydrogen gas permeation activation energy, and high hydrogen permeation efficiency, stability, and carbon deposition resistance, and has a long life when used as a composite membrane (particularly for hydrogen production by steam reforming).

Description

Detailed Description of the Invention

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the rights and benefit of Chinese Patent Applications Nos. 202210841761.4, 202210843337.3, 202210843306.8, and 202210843326.5, filed on July 18, 2022, the contents of which are incorporated herein by reference. [Technical Field]

[0002] The present invention relates to the field of palladium-based alloy materials, and in particular to palladium-based composite alloy materials, their manufacturing methods and uses. [Background technology]

[0003] The hydrogen production process using methanol steam reforming has attracted considerable attention due to its abundant methanol supply, convenient storage and transportation, high hydrogen storage capacity per unit mass of methanol, and low reaction temperature. Currently, research on catalysts for hydrogen production using methanol steam reforming is becoming increasingly mature. The CuO / ZnO / Al2O3 catalyst is the most representative catalyst, suitable for reaction temperatures between 150 and 350°C. Because 100% methanol conversion is difficult to achieve, and the target H2 inevitably contains components such as CO, CO2, and H2O, subsequent separation and purification are particularly important. Currently, relatively mature hydrogen gas separation processes include cryogenic separation, pressure swing adsorption, and membrane separation. Among these, membrane separation has the advantages of low noise (typically 30-40 decibels) and compactness, making it particularly suitable for small- to medium-scale applications requiring high purity hydrogen gas, such as in the electronics and semiconductor industries. In membrane separation processes, metallic palladium and its alloy membranes have a single selective permeability for hydrogen gas based on the dissolution-diffusion principle. The dense membrane material can block other impurity gases. This theoretically allows for 100% separation and purification of hydrogen gas, making them suitable for product separation. For example, CN108686522A discloses the use of high-temperature resistant palladium alloy composite membranes in hydrogen production by steam reforming. Palladium alloy composite membranes with thicknesses of 1-10 μm supported on tubular ceramic supports are used in the hydrogen production reaction by steam reforming. However, the application of palladium membranes in methanol steam reforming systems has several issues that urgently need to be resolved: 1) After dissolving hydrogen at low temperatures (<573 K), ultrathin palladium membranes are prone to hydrogen embrittlement and fracture due to a rapid change in lattice parameter. 2) As the reaction progresses, carbon deposition on the surface of the palladium membrane increases the hydrogen permeation activation energy, slowing the hydrogen permeation and diffusion rate and affecting the product separation and purification efficiency. 3) The non-precious metal catalyst and the precious metal palladium membrane material are in direct contact, and the interaction between the non-precious metal catalyst and the precious metal palladium membrane material is likely to reduce the hydrogen gas permeation and diffusion rate and catalytic activity.4) Depending on the raw material source, sulfur-containing compounds may be present in the reaction system. Trace amounts of sulfur-containing compounds, such as hydrogen sulfide and methyl sulfide, are more likely to adsorb and accumulate on the surface of palladium membranes than hydrogen gas. Palladium membranes are easily poisoned by prolonged exposure to sulfur-containing atmospheres, forming palladium sulfide (PdS), which adversely affects the permeation and diffusion efficiency of hydrogen gas. Prior technology has not made any breakthroughs in addressing the sulfur tolerance issue of palladium membranes. 5) The hydrogen production reaction process using methanol steam reforming inevitably generates large amounts of carbon dioxide. However, further development of this process is limited by a series of environmental issues, including the greenhouse effect caused by carbon dioxide emissions. Therefore, the challenge for this system is how to achieve comprehensive utilization, including carbon dioxide capture and conversion, through the structural design of membrane reactors, ultimately achieving "zero carbon emissions." Summary of the Invention [Problem to be solved by the invention]

[0004] The object of the present invention is to overcome the problems existing in the prior art and to provide a palladium-based composite alloy material, its manufacturing method and use. [Means for solving the problem] In order to achieve the above object, one aspect of the present invention provides a palladium-based composite alloy material containing Pd and a Group IB metal element, in which the half-width of at least one characteristic peak within a 2θ range of 5° to 90° in an XRD spectrum is 0.1745 or less.

[0005] A second aspect of the present invention comprises the steps of depositing Pd and a Group IB metal on a support, and then alloying the support on which the Pd and Group IB metal have been deposited; The alloying treatment method comprises first performing a heat treatment at a temperature of 350°C or higher in an activation atmosphere, and then lowering the temperature to 200°C or lower at a rate of more than 5°C / min, and the gas providing the activation atmosphere optionally contains an alkaline gas.

[0006] A third aspect of the present invention provides a palladium-based composite alloy material produced by the method according to the second aspect.

[0007] A fourth aspect of the present invention provides a composite membrane comprising a palladium-based composite alloy material and a hydrophobic group-modified silicon-aluminum molecular sieve attached to the surface of the palladium-based composite alloy material, wherein the palladium-based composite alloy material is the above-mentioned palladium-based composite alloy material.

[0008] A fifth aspect of the present invention provides the use of the composite membrane described above in hydrogen production by steam reforming.

[0009] A sixth aspect of the present invention is Provided is a method for producing hydrogen by steam reforming, the method comprising the steps of: introducing alcohol and steam into a first reactor provided with a first composite membrane in the presence of a catalyst to carry out a reforming reaction, the first composite membrane being the composite membrane described above; introducing the alcohol and steam into a side of the hydrophobic-group-modified silicon-aluminum molecular sieve that is closer to the first composite membrane; and allowing hydrogen gas produced by the reforming reaction to pass through one side of the hydrophobic-group-modified silicon-aluminum molecular sieve, permeate the first composite membrane, and be removed from the first reactor. [Effects of the Invention]

[0010] According to the above technical solution, the composite membrane made of the palladium-based composite alloy material of the present invention has low hydrogen gas permeation activation energy, high hydrogen permeation efficiency and stability, and high carbon deposition resistance, which further extends the service life of the composite membrane. Furthermore, when the composite membrane of the present invention is used in hydrogen production by steam reforming, the catalytic reaction activity of the catalyst and the mechanical structural integrity of the palladium-based composite alloy material can be ensured.

[0011] According to a preferred embodiment of the present invention, by using a molecular sieve as a protective layer for a palladium-based composite alloy material, the resulting composite membrane has a high hydrogen gas permeation and diffusion rate, and since the non-precious metal catalyst and the precious metal palladium membrane material are not in direct contact with each other, the hydrogen gas permeation and diffusion rate and catalytic activity are less affected and are stable.

[0012] According to another preferred embodiment of the present invention, the hydrophobized composite membrane has higher sulfur resistance and carbon deposition resistance, lower hydrogen gas permeation activation energy, and longer service life. The sulfur-resistant metal oxide nanoparticles on the surface of the molecular sieve can activate and decompose sulfur-containing compounds, further improving the sulfur resistance of the composite membrane.

[0013] According to a further preferred embodiment of the present invention, the composite membrane of the present invention is combined with other palladium membranes to capture or convert carbon dioxide obtained from hydrogen production by steam reforming and convert the carbon dioxide into high-value-added products, thereby improving the overall utilization rate of carbon dioxide and alleviating the environmental problems caused by carbon dioxide. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a schematic diagram of hydrogen production by alcohol-based steam reforming over a hydrophobized ZSM-5 / PdAu composite membrane. 2a to 2c are XRD characteristic spectra of the structures of the palladium-based composite alloy material and the molecular sieve. FIG. 3 shows experimental diagrams of contact angles between the composite film and various liquids before hydrophobization treatment. FIG. 4 shows experimental diagrams of contact angles between the composite film and various liquids after hydrophobic treatment. Figure 5 shows the results of infrared characterization of the hydroxyl groups before and after the hydrophobic treatment. FIG. 6 shows the results of NMR characterization before and after the hydrophobic treatment. Figure 7 is a scanning electron microscope (SEM) image of the surface of the composite membrane after loading MoO2 nanoparticles. FIG. 8 is a schematic diagram of the structure when the catalyst and composite membrane are packaged and placed in a tubular reactor. [Mode for Carrying Out the Invention]

[0015] The ranges and endpoints of any values disclosed herein are not limited to the precise ranges or values, but should be understood to include values approaching such ranges or values. In the case of numerical ranges, the range endpoints, the range endpoints and individual point values, and the individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges shall be considered to be specifically disclosed herein.

[0016] The present invention provides a palladium-based composite alloy material comprising Pd and a Group IB metal element, and characterized in that in an XRD spectrum, at least one characteristic peak within a 2θ range of 5° to 90° has a half-value width of 0.1745 or less.

[0017] In the present invention, the crystal structure of the palladium-based composite alloy material is face-centered cubic close-packed (FCC) or body-centered cubic (BCC). "Face-centered cubic close-packed" refers to the 14 atoms involved in a unit cell belonging to four layers, with one vertex designated as layer A, the three face-centered atoms and the three vertex-corner atoms adjacent to it belonging to layer B, and the next six atoms belonging to layer C, with one vertex opposite the vertex angle of layer A being in layer A of the next cycle. "Body-centered cubic packing" refers to one of the closest packing methods in a cubic crystal system, containing two lattice points, one at a vertex and one at the body center. That is, eight atoms are located at the eight vertices of a cube, one atom at the center of the cube, and each of the eight vertex atoms is adjacent to the atom at the center.

[0018] In the present invention, the lattice parameter k of the palladium-based composite alloy material is 0.3836 to 0.4369 nm, preferably 0.4075 to 0.4289 nm. The "lattice parameter k" refers to the physical size of a unit cell in a lattice and represents a basic structural parameter of a crystalline substance. The lattice parameter k represents the edge length of the unit cell, i.e., the edge length of each parallelepiped cell, and is directly related to the interatomic bond energy. A unit cell in three-dimensional space generally has three lattice parameters, a, b, and c, and is distributed in the form of a Bravais lattice. In the cubic crystal structure of the present invention, these three constants are equal, so the lattice parameter k can be expressed by the parameter k. Changes in k reflect changes in the internal components of the crystal, the state under stress, etc. The lattice parameter k can be measured using X-ray diffraction analysis (XRD) or atomic force microscopy (AFM).

[0019] According to a preferred embodiment of the present invention, in the XRD spectrum of the palladium-based composite alloy material, the half-value width of all characteristic peaks within a 2θ range of 5° to 90° is 0.1745 or less, more preferably 0.084 or less, 0.078 or less, 0.072 or less, 0.069 or less, 0.064 or less, 0.055 or less, 0.039 or less, usually 0.01 or more, 0.017 or more, 0.029 or more, 0.031 or more, 0.032 or more, 0.052 or more, 0.059 or more, 0.062 or more, 0.068 or more, 0.073 or more, and further preferably 0.017 or more.

[0020] More preferably, when the palladium-based composite alloy material has a face-centered cubic close-packed structure, in its XRD spectrum, the half-width of the characteristic peak at 2θ=40°±1° (i.e., the characteristic peak of the crystal plane (110)) is 0.0555 or less, or 0.0198 or less, or the half-width of the characteristic peak at 2θ=46°±1° (i.e., the characteristic peak of the crystal plane (111)) is 0.0699 or less, or 0.0332 or less, or The half-width of the characteristic peak at 2θ=83°±1° (i.e., the characteristic peak of the crystal plane (220)) is 0.0873 or less, or 0.0352 or less, or the half-width of the characteristic peak at 2θ=83°±1° (i.e., the characteristic peak of the crystal plane (311)) is 0.1047 or less, or 0.039 or less, or the half-width of the characteristic peak at 2θ=87°±1° (i.e., the characteristic peak of the crystal plane (222)) is 0.1396 or less, or 0.0402 or less. Furthermore, in the XRD spectrum of the palladium-based composite alloy material, the half width of the characteristic peak at 2θ=40°±1° is in the range of 0.017 to 0.02, or the half width of the characteristic peak at 2θ=46°±1° is in the range of 0.017 to 0.034, or the half width of the characteristic peak at 2θ=69°±1° is in the range of 0.029 to 0.036, or the half width of the characteristic peak at 2θ=83°±1° is in the range of 0.031 to 0.039, or the half width of the characteristic peak at 2θ=87°±1° is in the range of 0.032 to 0.041.

[0021] More preferably, when the palladium-based composite alloy material has a body-centered cubic packed structure, in its XRD spectrum, the half-width of the characteristic peak at 2θ=43°±1° (i.e., the characteristic peak of the crystal plane (110)) is 0.0722 or less, or 0.058 or less, or the half-width of the characteristic peak at 2θ=53°±1° (i.e., the characteristic peak of the crystal plane (111)) is 0.0873 or less, or 0.073 or less, or The half-width of the characteristic peak at 2θ=70°±1° (i.e., the characteristic peak of the crystal plane (200)) is 0.0873 or less, or 0.086 or less, or the half-width of the characteristic peak at 2θ=70°±1° (i.e., the characteristic peak of the crystal plane (210)) is 0.1047 or less, or 0.088 or less, or the half-width of the characteristic peak at 2θ=79°±1° (i.e., the characteristic peak of the crystal plane (211)) is 0.1571 or less, or 0.103 or less. Furthermore, in the XRD spectrum of the palladium-based composite alloy material, the half-width of the characteristic peak at 2θ = 43° ± 1° is in the range of 0.017 to 0.041, or the half-width of the characteristic peak at 2θ = 53° ± 1° is in the range of 0.024 to 0.055, or the half-width of the characteristic peak at 2θ = 62° ± 1° is in the range of 0.036 to 0.066, or the half-width of the characteristic peak at 2θ = 70° ± 1° is in the range of 0.047 to 0.068, or the half-width of the characteristic peak at 2θ = 79° ± 1° is in the range of 0.051 to 0.074. The "half-width" is defined as the peak width at half the peak height, i.e., the half-height width, and is expressed in radians by converting the half-height width to radians using the Debye-Scherrer equation (D = Kγ / B cosθ). In the palladium-based composite alloy material, when no characteristic peak exists at the corresponding 2θ, the half-value width is considered to be zero.

[0022] According to the palladium-based composite alloy material of the present invention, the Group IB metal element can improve the permeation and diffusion properties such as hydrogen gas solubility and diffusion coefficient of the obtained palladium-based composite alloy material, and may be at least one of Cu, Ag, and Au, but Au is preferred.

[0023] According to the palladium-based composite alloy material of the present invention, the Group IB metal element is Au, and in the XRD spectrum of the palladium-based composite alloy material, the half width of the characteristic peak at 2θ=40°±1° is FWHM1, the half width of the characteristic peak at 2θ=46°±1° is FWHM2, the half width of the characteristic peak at 2θ=69°±1° is FWHM3, the half width of the characteristic peak at 2θ=83°±1° is FWHM4, and the half width of the characteristic peak at 2θ=87°±1° is FWHM5, satisfying the following formula I: FWHM x =(FWHM x-1 +FWHM x+1 ) / 2±W Formula I Here, x is 2, 3, or 4, and W is 0.0003 to 0.0064. A palladium-based composite alloy material whose half width of the characteristic peak satisfies formula I has better hydrogen permeation efficiency and stability.

[0024] The palladium-based composite alloy material according to the present invention may further contain Ni. Preferably, the molar ratio of Pd to Ni is 1:(0.35 to 0.65).

[0025] According to the palladium-based composite alloy material of the present invention, the palladium-based composite alloy material is a film-like material, and the thickness of the palladium-based composite alloy material may be 0.5 to 30 μm, but is preferably 5 to 15 μm.

[0026] According to one embodiment of the present invention, the palladium-based composite alloy material may be a palladium-based composite alloy material E, which will be described later.

[0027] As a result of research, the inventors have found that alloying treatment by a specific method is particularly advantageous in improving the hydrogen permeability and stability of the resulting palladium-based composite alloy material. Therefore, the present invention also provides a method for producing a palladium-based composite alloy material, comprising the steps of depositing Pd, a Group IB metal, and optionally Ni on a support, and then alloying the support on which Pd, a Group IB metal, and optionally Ni have been deposited, wherein the molar ratio of Pd to the Group IB metal is preferably 1:(0.01 to 10), more preferably 1:(0.1 to 1.6), and even more preferably 1:(0.2 to 0.8).

[0028] Here, the alloying treatment method involves first performing heat treatment in an activation atmosphere at a temperature of 350°C or higher (e.g., 500°C, 540°C, 550°C, 560°C, 570°C, 580°C, 590°C, 600°C, or any value between the above values), and then lowering the temperature to 200°C or lower at a rate of more than 5°C / min (e.g., 30, 35, 40, 45, 55, 65, 70, 80, 100°C / min, etc., or any value between the above values), and the gas providing the activation atmosphere optionally contains an alkaline gas.

[0029] In the present invention, the molar ratio of the Group IB metal element (or Group IB metal) to Pd may be 0.05, 0.1, 0.2, 0.25, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 3, 5, 8, 9, or any value between the above values, but is preferably 0.1 to 1.6, and more preferably 0.2 to 0.8.

[0030] In the present invention, the molar ratio of Ni to Pd is preferably 0.35 to 0.65, for example, 0.4, 0.45, 0.5, 0.55, 0.58, 0.6, 0.62, or any value between the above values.

[0031] In the present invention, the Group IB metal may be at least one of Cu, Ag, and Au, and is preferably Au.

[0032] In a preferred embodiment of the present invention, the alloying treatment is carried out in an active atmosphere at a temperature of 350 to 650°C and a pressure of 0.12 to 0.75 MPa for 2 to 10 hours, and then cooled to 100 to 200°C at a rate of 25 to 150°C / min. The palladium-based composite alloy material obtained by this embodiment has higher hydrogen permeability and stability.

[0033] In the present invention, the gas providing the activation atmosphere may be any of a variety of gases commonly used in the art that are gaseous under alloying treatment conditions. Preferably, the activation atmosphere is provided by at least one of a rare gas (e.g., Ar), N2, water vapor, H2, an acidic gas (e.g., CO2), and an alkaline gas (ethylenediamine, NH3, PH3, or N2H4). According to a preferred embodiment of the present invention, the gas providing the activation atmosphere contains hydrogen gas and nitrogen gas, and the hydrogen gas content in the mixed gas of hydrogen gas and nitrogen gas is 30% by volume or more, more preferably 35 to 70% by volume. In particular, the addition of an alkaline gas accelerates the activation of the palladium-based alloy film, stabilizes the formed face-centered cubic structure, and reduces the half-width of the characteristic peak in the XRD spectrum. Therefore, the gas providing the activation atmosphere preferably contains an alkaline gas.

[0034] According to a preferred embodiment of the present invention, the gas providing the activation atmosphere contains hydrogen gas and alkaline gas. More preferably, the content of alkaline gas in the gas providing the activation atmosphere is 20% by volume or more, for example, 22%, 25%, 28%, 30%, 40%, 50%, or any value between the above values, more preferably 30% by volume or more. Similar effects can be obtained even if the gas providing the activation atmosphere is alkaline gas only.

[0035] The alkaline gas may be an organic alkaline gas or an inorganic alkaline gas, and more preferably, the alkaline gas is at least one selected from ethylenediamine, NH3, PH3 (phosphine), and N2H4 (hydrazine).

[0036] In the present invention, the pressure of the alloying process is generally controlled by adjusting the amount of gas that provides the activating atmosphere. After the temperature is reduced to below 200°C at a specific rate, it can be cooled to room temperature for later use.

[0037] In a preferred embodiment of the present invention, the total thickness of Pd and Group IB metal deposited on the support is 0.5 to 30 μm, preferably 5 to 15 μm. The method for depositing Pd and Group IB metal on the support may be any method commonly used in the art, such as at least one of vapor deposition (e.g., physical vapor deposition or chemical vapor deposition), electroless plating, electroplating, and electroforming, and preferably at least one of electroplating and electroless plating.

[0038] In a preferred embodiment of the present invention, the thickness of the support is 0.1 to 20 mm, preferably 2 to 5 mm. The support can be made of a material commonly used in the art that can withstand the operating temperature of the present invention without affecting hydrogen permeability, i.e., does not deform at the operating temperature and does not affect hydrogen permeability. To ensure excellent hydrogen permeability, as well as to obtain better mechanical and thermal stability and reduce the amount of palladium used (reducing costs), the support is preferably a porous support, which may be at least one selected from porous ceramic, porous glass, porous metal (e.g., porous stainless steel), porous quartz, and polymers, but is more preferably at least one selected from porous ceramics, porous metals, and polymers. Generally, the support has a porosity distribution range of 15 to 75% and an average pore diameter of 0.05 to 0.4 μm. To obtain a tubular membrane, the support is preferably a tubular support. The porous ceramic may be made of γ-Al2O3 with a porosity distribution range of 25-66% and an average pore diameter of 0.12-0.4 μm. The porous stainless steel may be made of 316L (Fe) with a porosity distribution range of 32-71% and an average pore diameter of 0.08-0.36 μm. 69 Cr 17 Ni 12The polymer may be a polyimide material having a porosity distribution range of 15 to 37% and an average pore diameter of 0.05 to 0.22 μm. The "porosity distribution range" can be measured by nitrogen physical adsorption. The "average pore diameter" can be measured by nitrogen physical adsorption.

[0039] The present invention also provides a palladium-based composite alloy material produced by the above method.

[0040] According to the present invention, in order to further improve the properties of the palladium-based composite alloy material, such as sulfur resistance, chlorine resistance, and carbon precipitation resistance, the palladium-based composite alloy material can be covered with a protective layer, and the protective layer can improve the hydrogen permeability (E act , J H2 , and J N2 ), and a protective layer commonly used in this field, such as a modified or unmodified molecular sieve, can be used. The present invention further provides a composite membrane comprising a palladium-based composite alloy material and a hydrophobic group-modified silicon-aluminum molecular sieve attached to the surface of the palladium-based composite alloy material, wherein the palladium-based composite alloy material is the above-mentioned palladium-based composite alloy material or a palladium-based composite alloy material produced by the above-mentioned method.

[0041] According to the composite film of the present invention, the water contact angle of the composite film is preferably 90° or more, more preferably 105° or more.

[0042] In the composite membrane of the present invention, the composite membrane is preferably a tubular membrane.

[0043] According to the composite membrane of the present invention, the composite membrane further comprises a support, and the palladium-based composite alloy material is attached to the support, and the thickness and type of the support are as described above, and will not be described in detail here.

[0044] According to the composite membrane of the present invention, the hydrophobic group-modified silicon-aluminum molecular sieve 29In the Si MAS nuclear magnetic resonance spectrum, the peak area ratio of peaks at chemical shifts of -113 ppm and -103 ppm (ie, Q4 / Q3) is 6-12.

[0045] According to the composite membrane of the present invention, the hydrophobic groups in the hydrophobic group-modified silicon-aluminum molecular sieve can be provided by a substance that improves the hydrophobicity of the molecular sieve by binding to the molecular sieve through electrostatic adsorption or coordinate bonding, such as at least one of polymethylhydrogensiloxane, vinyltriethoxysilane, 3-aminopropyltriethylsilane, N,N-diethyltrimethylsilane, 3-aminopropyltrimethoxysilane, (3-mercaptopropyl)trimethoxysilane, 3-aminopropyltriethoxysilane, N,N-diethyl-3-(trimethoxysilyl)propylamine, 1-[3-(trimethoxysilyl)propyl]urea, (3-chloropropyl)trimethoxysilane, and 3-chloropropyltriethoxysilane, and preferably at least one of polymethylhydrogensiloxane, vinyltriethoxysilane, 3-aminopropyltriethylsilane, N,N-diethyltrimethylsilane, and 3-aminopropyltrimethoxysilane.

[0046] According to the composite membrane of the present invention, the silicon-aluminum molecular sieve is at least one of ZSM-5, ZSM-11, ZSM-12, ZSM-23, ZSM-34, 3A molecular sieve, 4A molecular sieve, 5A molecular sieve, SAPO-31, SAPO-34, SAPO-44, RUB-13, MCM-68, Y-type molecular sieve, and mordenite, more preferably ZSM-5 molecular sieve. The combination of the preferred molecular sieve of the present invention with a palladium-based composite alloy material can further improve the efficiency of hydrogen production by reforming.

[0047] According to the composite membrane of the present invention, the thickness of the hydrophobic group-modified silicon-aluminum molecular sieve may be 1 to 100 μm, preferably 5 to 30 μm.

[0048] According to the composite membrane of the present invention, the molar ratio of silicon to aluminum in the hydrophobic-group-modified silicon-aluminum molecular sieve may be (2 to 100):1, preferably (2.5 to 20):1. The average particle size of the hydrophobic-group-modified silicon-aluminum molecular sieve may be 60 to 380 nm, preferably 150 to 200 nm. The average pore size of the hydrophobic-group-modified silicon-aluminum molecular sieve may be 0.3 to 230 nm, preferably 1 to 18 nm. The specific surface area of the hydrophobic-group-modified silicon-aluminum molecular sieve may be 35 to 750 m. 2 / g, preferably 65 to 480m 2 The crystallinity of the hydrophobic group-modified silicon-aluminum molecular sieve may be 90% or more, and preferably 95 to 99%.

[0049] According to the composite membrane of the present invention, in order to improve the sulfur tolerance of the composite membrane of the present invention and to accommodate hydrogen production by reforming a sulfur-containing raw material, the composite membrane may further comprise Group VIB metal oxide nanoparticles attached to the surface of the hydrophobic-group-modified silicon-aluminum molecular sieve. Preferably, the Group VIB metal is Mo and / or W (or the Group VIB metal oxide is MoO2 and / or WO3), more preferably Mo (or the Group VIB metal oxide is MoO2). Preferably, the average particle size of the Group VIB metal oxide nanoparticles is 50 to 200 nm. Preferably, the content of the Group VIB metal oxide nanoparticles is such that the molar ratio of the Group VIB metal to Pd is 0.01 to 0.5. In a preferred embodiment, as shown in FIGS. 1 and 8, the composite membrane comprises a support 1, a palladium-based composite alloy material 2, a hydrophobic-group-modified silicon-aluminum molecular sieve 3, and optional Group VIB metal oxide nanoparticles, which are sequentially attached to the support 1. When the composite membrane of the present invention is used for hydrogen production by reforming, by further attaching a catalyst 4 for catalyzing the reforming reaction, the reforming reaction proceeds on the side closer to the catalyst, and the generated hydrogen gas passes through any Group VIB metal oxide nanoparticles that may be present, the hydrophobic group-modified silicon-aluminum molecular sieve 3, the palladium-based composite alloy material 2, and the support 1 in this order.

[0050] The present invention also provides (1) depositing Pd, a Group IB metal, and optionally Ni on a support, and then alloying the support on which Pd, a Group IB metal, and optionally Ni have been deposited, wherein the molar ratio of Pd to the Group IB metal is preferably 1:(0.01 to 10), more preferably 1:(0.1 to 1.6), and even more preferably 1:(0.2 to 0.8); The alloying treatment method comprises the steps of first performing a heat treatment at a temperature of 350°C or higher in an activation atmosphere, and then decreasing the temperature to 200°C or lower at a rate of more than 5°C / min, wherein the activation atmosphere optionally contains an alkaline gas; (2) placing the alloyed material into a solution containing a silicon-aluminum molecular sieve precursor, and sequentially carrying out hydrothermal crystallization, drying, and calcination to obtain a composite membrane precursor; (3) modifying the composite membrane precursor with a hydrophobic group.

[0051] In the method for producing the composite membrane, the alloying treatment method in step (1), the Group IB metal, the activation atmosphere, the support, etc. are as described above, and will not be described in detail here.

[0052] In the method for preparing the composite membrane, the solution containing the precursor of the silicon-aluminum molecular sieve generally contains a silicon source, an aluminum source, a template agent, and water.

[0053] Preferably, the molar ratio of the silicon source, aluminum source, template agent, and water is 100:(1-50):(10-55):(50-2750), more preferably 100:(5-40):(25-50):(75-1500).

[0054] Preferably, the amount of the solution containing the precursor of the silicon-aluminum molecular sieve is 0.05 to 2 ml per 1 g of the alloyed material.

[0055] Here, the silicon source may be a substance commonly known in the art that can provide silicon element, but is preferably at least one of silicate ester, silicate, and silicon dioxide, and more preferably at least one selected from tetrabutyl orthosilicate, tetraethyl orthosilicate, sodium silicate, potassium silicate, silica sol, and water glass.

[0056] Here, the aluminum source may be a substance commonly known in the art that can provide aluminum element, but is preferably at least one of metaaluminate, aluminum oxide, aluminum salt, aluminum sol, and organic aluminum alkoxide, and more preferably at least one selected from sodium metaaluminate, pseudoboehmite, aluminum sulfate, aluminum nitrate, and aluminum isopropoxide.

[0057] Preferably, the template agent is at least one of tetraalkylammonium hydroxide, alkylamine, and tetraalkylammonium halide, and more preferably at least one selected from tetrabutylammonium hydroxide, tetrapropylammonium hydroxide, tetraethylammonium hydroxide, triethylamine, cetyltrimethylamine bromide, and isopropylamine.

[0058] In the method for producing the composite membrane, the hydrothermal crystallization can be carried out by aging followed by crystallization.

[0059] Preferably, the aging conditions include an aging temperature of 60 to 90°C.

[0060] Preferably, the aging conditions further include an aging time of 3 to 9 hours.

[0061] Preferably, the crystallization conditions include a crystallization temperature of 150 to 185°C.

[0062] Preferably, the crystallization conditions further include a crystallization time of 12 to 72 hours.

[0063] The aging of the present invention can be carried out under stirring conditions, but the stirring speed for aging is preferably 600 to 1200 rpm. The crystallization of the present invention can also be carried out under stirring conditions, but the stirring speed for aging is preferably 15 to 30 rpm.

[0064] In the method for producing a composite membrane, there are no special requirements for the drying conditions, which may include a drying temperature of 50 to 80° C. The drying conditions may also include a drying time of 4 to 18 hours.

[0065] In the method for producing a composite membrane, the roasting conditions preferably include a roasting temperature of 500 to 650° C. Preferably, the roasting conditions further include a roasting time of 4 to 10 hours.

[0066] In the method for producing a composite membrane, the method for modifying the composite membrane precursor with a hydrophobic group is preferably a method of silanizing the composite membrane precursor with a silanizing reagent, and a chemical vapor deposition method can be used.

[0067] Preferably, the amount of the silanizing reagent used is 3 to 9 ml per 1 g of the composite film precursor.

[0068] Preferably, the silanizing reagent can be selected from substances commonly used in the art that can silanize molecular sieves to improve their hydrophobicity. For example, the silanizing reagent is at least one selected from polymethylhydrogensiloxane, vinyltriethoxysilane, 3-aminopropyltriethylsilane, N,N-diethyltrimethylsilane, 3-aminopropyltrimethoxysilane, (3-mercaptopropyl)trimethoxysilane, 3-aminopropyltriethoxysilane, N,N-diethyl-3-(trimethoxysilyl)propylamine, 1-[3-(trimethoxysilyl)propyl]urea, (3-chloropropyl)trimethoxysilane, and 3-chloropropyltriethoxysilane. Preferably, the silanizing reagent is at least one selected from polymethylhydrogensiloxane, vinyltriethoxysilane, 3-aminopropyltriethylsilane, N,N-diethyltrimethylsilane, and 3-aminopropyltrimethoxysilane.

[0069] Preferably, the silanization conditions may include a temperature of 15 to 75°C, preferably 30 to 55°C, and a pressure of 10 to 70 kPa. The silanization reagent may be introduced by a purge gas (N, rare gas, CO, etc.), and the flow rate of the purge gas may be 35 to 75 ml / min.

[0070] The method for producing the composite membrane may further include a step (4) of depositing Group VIB metal oxide nanoparticles on the surface of the hydrophobic group-modified product obtained in step (3) to improve the sulfur resistance of the composite membrane.

[0071] Preferably, the Group VIB metal is Mo and / or W (or the Group VIB metal oxide is MoO2 and / or WO3), more preferably Mo (or the Group VIB metal oxide is MoO2).

[0072] Preferably, the average particle size of the Group VIB metal oxide nanoparticles is 50 to 200 nm.

[0073] Preferably, the amount of the Group VIB metal oxide nanoparticles deposited is such that the molar ratio of the Group VIB metal to Pd is 0.01 to 0.5.

[0074] In the method for preparing the composite membrane, the method for depositing the Group VIB metal oxide nanoparticles can be, but is not limited to, in situ synthesis using a hydrothermal synthesis method. Specifically, the method may include immersing the hydrophobic group-modified product obtained in step (3) in a solution containing a Group VIB metal precursor under hydrothermal synthesis conditions. Preferably, the concentration of the Group VIB metal element in the solution containing the Group VIB metal precursor is 0.01-0.55 mol / L. Here, the Group VIB metal precursor may be selected from molybdates and / or tungstates, and is preferably at least one of (NH)MoO, sodium tungstate, sodium molybdate, potassium molybdate, and strontium molybdate. According to a specific embodiment of the present invention, the solution containing the Group VIB metal precursor contains (NH)MoO, (NH)CO, NH, and LiOH in a molar ratio of 1:(1-5):(5-8):(2-5). Preferably, the conditions for the hydrothermal synthesis (immersion) may include a temperature of 150 to 250° C. and a time of 24 to 40 hours.

[0075] The present invention also relates to a composite membrane produced by the above-mentioned method for producing a composite membrane.

[0076] The present invention also provides the use of the above composite membrane in hydrogen production by steam reforming.

[0077] By using the composite membrane of the present invention, it is possible to obtain high-purity hydrogen gas with a purity of more than 99.999%. a step of introducing alcohol and steam into a first reactor provided with a first composite membrane in the presence of a catalyst to carry out a reforming reaction, the first composite membrane being the composite membrane described above, the alcohol and steam being introduced from a side of the hydrophobic-group-modified silicon-aluminum molecular sieve close to the first composite membrane, hydrogen gas produced by the reforming reaction passing through one side of the hydrophobic-group-modified silicon-aluminum molecular sieve, permeating the first composite membrane, and being taken out of the first reactor; Optionally, the method for producing hydrogen by steam reforming further comprises the step of introducing the gas that has not permeated the first composite membrane into a second reactor provided with a second composite membrane to capture or convert carbon dioxide.

[0078] In the method for producing hydrogen by steam reforming, the alcohol may be a monohydric alcohol having 1 to 6 carbon atoms and / or a dihydric alcohol having 1 to 6 carbon atoms, and is preferably at least one of methanol, ethanol, ethylene glycol, and propylene glycol.

[0079] In the method for producing hydrogen by steam reforming, the catalyst may be a catalyst commonly used in the art for producing hydrogen by steam reforming, such as at least one of CuO / ZnO / Al2O3, Ru / Al2O3, Cu-Ir / Al2O3, Pd / ZnO, CuO / Fe2O3 / ZrO2, CuO / La2O3 / ZrO2, CuO / ZnO / ZrO2 / Al2O3, and CuO / ZnO / La2O3 / Al2O3, but is preferably at least one selected from CuO / ZnO / Al2O3, Pd / ZnO, and CuO / Fe2O3 / ZrO2. Among these, in the CuO / ZnO / Al2O3 catalyst, the molar ratio of Cu, Zn, and Al may be 1:(0.1-2):(0.05-2.2), preferably 1:(0.2-1.25):(0.1-1.25). In the Pd / ZnO catalyst, the molar ratio of Pd to ZnO may be 1:(0.5-15), preferably 1:(2.5-8). In the CuO / Fe2O3 / ZrO2 catalyst, the molar ratio of Cu, Fe, and Zr may be 1:(0.01-0.75):(0.1-5.6), preferably 1:(0.02-0.65):(0.8-2.3).

[0080] In the method for producing hydrogen by steam reforming, the volume ratio of alcohol to steam may be 1:(0.2 to 6.8), and preferably 1:(0.5 to 3).

[0081] In the method for producing hydrogen by steam reforming, the conditions for the reforming reaction may include a temperature of 125 to 725°C, preferably 175 to 475°C. The space velocity of the alcohol and steam (raw material gas) may be 1250 to 25500 h -1 , preferably 3750 to 15000h -1 The conditions for the reforming reaction may further include a pressure of 0.01 to 1.25 MPa, preferably 0.05 to 0.75 MPa.

[0082] The method for producing hydrogen by steam reforming further includes a step of introducing the gas that does not permeate the first composite membrane into a second reactor provided with a second composite membrane to capture (physically capture) or convert (chemically) carbon dioxide.

[0083] The inventors have found through research that there is a certain correlation between the hydrogen gas permeation and diffusion rate and the value of the lattice parameter of a palladium membrane, and that by determining the lattice parameter of a palladium membrane according to the required hydrogen gas permeation and diffusion rate and selecting the manufacturing process or raw materials according to the lattice parameter, the manufacturing process and raw materials can be simplified, thereby making the manufacture and use of palladium membranes more targeted. Therefore, according to one embodiment of the present invention, the method for producing hydrogen by steam reforming is characterized by determining the hydrogen gas permeation and diffusion rate J required for carbon dioxide capture or conversion. H2 (Generally 0.2 to 0.4 mol m -2 ·s -1 ), providing a second composite membrane (particularly, a palladium membrane not containing Au) containing the palladium membrane having the lattice parameter k, and capturing or converting carbon dioxide in the presence of the provided second composite membrane. Preferably, the hydrogen gas permeation and diffusion rates J H2 and the lattice parameter k satisfy Equation II.

number

[0084] Preferably, when the material of the palladium film is a PdCu alloy, the value of b is in the range of 0.54 to 1.25.

[0085] Preferably, when the material of the palladium membrane is a PdAg alloy, the value of b is in the range of 0.61 to 1.68.

[0086] Preferably, when the material of the palladium film is a PdAu alloy, the value of b is in the range of 0.7 to 3.

[0087] Preferably, when the material of the palladium membrane is a PdCuAg alloy, the value of b is in the range of 0.59 to 1.62.

[0088] Preferably, when the material of the palladium film is a PdCuAu alloy, the value of b is in the range of 0.75 to 2.65.

[0089] Preferably, when the material of the palladium membrane is a PdCuNi alloy, the value of b is in the range of 0.51 to 1.22.

[0090] The hydrogen gas permeation and diffusion rates of several palladium-based alloy materials that satisfy the above formula II, and the lattice parameter values of the palladium membranes are shown below.

[0091] [Table 1] JPEG2025525455000004.jpg245169

[0092] According to a preferred embodiment of the present invention, the second composite membrane includes a palladium membrane and a silicon-aluminum molecular sieve carrying sodium-modified nano-FeO attached to the surface of the palladium membrane (i.e., the silicon-aluminum molecular sieve carries sodium-modified nano-FeO). The thickness of the palladium membrane may be 0.5 to 30 μm, preferably 5 to 15 μm. The material of the palladium membrane may be metallic palladium or a palladium alloy, but is preferably the above-mentioned palladium-based composite alloy material or the palladium-based composite alloy material E described below. The palladium-based composite alloy material E contains Pd, Cu, and Ag, with a molar ratio of Pd, Cu, and Ag of 100:(12 to 38):(9 to 25). The palladium-based composite alloy material E has a face-centered cubic close-packed crystal structure and a lattice parameter k of 0.4025 to 4255 nm.

[0093] According to the present invention, preferably, the half-value width of at least one characteristic peak within the 2θ range of 10° to 90° in the XRD spectrum of the palladium-based composite alloy material E is 0.1633 or less, more preferably, the half-value width of all characteristic peaks within the 2θ range of 10° to 90° in the XRD spectrum of the palladium-based composite alloy material E is 0.1633 or less, even more preferably, 0.084 or less, 0.078 or less, 0.072 or less, 0.069 or less, 0.064 or less, 0.055 or less, 0.039 or less, typically, 0.052 or more, 0.059 or more, 0.062 or more, 0.068 or more, 0.073 or more. More preferably, in the XRD spectrum of the composite palladium-based alloy material E, the half-width of the characteristic peak at 2θ=40°±1° (i.e., the characteristic peak of the crystal plane (110)) is 0.0698 or 0.055 or less, or the half-width of the characteristic peak at 2θ=46°±1° (i.e., the characteristic peak of the crystal plane (111)) is 0.0873 or 0.069 or less, or the half-width of the characteristic peak at 2θ=69°±1° is 0.0873 or 0.069 or less. The half-width of the characteristic peak (i.e., the characteristic peak of the crystal plane (220)) is 0.1047 or 0.072 or less, or the half-width of the characteristic peak at 2θ=83°±1° (i.e., the characteristic peak of the crystal plane (311)) is 0.1396 or 0.078 or less, or the half-width of the characteristic peak at 2θ=87°±1° (i.e., the characteristic peak of the crystal plane (222)) is 0.1633 or 0.084 or less.

[0094] Preferably, the second composite membrane is a tubular membrane.

[0095] Preferably, the second composite membrane may further include a support, and the palladium membrane (palladium-based composite alloy material E) is attached to the support, and the thickness of the support may be 0.1 to 20 mm, but more preferably 2 to 5 mm.

[0096] Preferably, the silicon-aluminum molecular sieve in the second composite membrane is at least one of HZSM-5, HZSM-11, HZSM-12, HZSM-23, HZSM-34, HY, HMCM-22, HBEA, and HMOR.

[0097] Preferably, the thickness of the sodium-modified nano-Fe3O4-loaded silicon-aluminum molecular sieve is 100 to 3750 nm, more preferably 350 to 1500 nm.

[0098] Preferably, the silicon-aluminum molecular sieve in the second composite membrane has a molar ratio of silicon element to aluminum element of (2 to 50):1, more preferably (5 to 20):1, an average particle size of 50 to 420 nm, more preferably 150 to 300 nm, an average pore size of 0.25 to 225 nm, more preferably 0.75 to 35 nm, and a specific surface area of 25 to 600 m 2 / g, more preferably 50 to 500m 2 / g, and the crystallinity is 92% or more, more preferably 96 to 99%.

[0099] Preferably, the average particle size of the sodium-modified nano Fe3O4 in the second composite film is 5 to 300 nm, preferably 10 to 100 nm.

[0100] Preferably, the amount of sodium-modified nano Fe3O4 loaded in the second composite film is such that the molar ratio of Pd to Fe is 1:(0.001 to 0.1), preferably 1:(0.001 to 0.03).

[0101] Preferably, the molar ratio of Na to Fe in the sodium-modified nano-Fe3O4 in the second composite film is 1:(1-10), preferably 1:(3-6).

[0102] According to the present invention, the method for producing the palladium-based composite alloy material E preferably includes the steps of depositing Pd, Cu, and Ag on a support, and then alloying the support on which the Pd, Cu, and Ag have been deposited, wherein the molar ratio of Pd, Cu, and Ag is 100:(12-38):(9-25). The alloying treatment is performed by first performing a heat treatment in an activation atmosphere at a temperature of 500-650°C (e.g., 500°C, 540°C, 550°C, 560°C, 570°C, 580°C, 590°C, 600°C, or any value therebetween) and a pressure of more than 0.1 MPa, and then cooling the temperature to 200°C or lower at a rate of more than 30°C / min (e.g., 31, 35, 40, 45, 55, 65, 70, 80, 100°C / min, or any value therebetween). As mentioned above, the gas providing the activation atmosphere may optionally contain an alkaline gas, but this will not be described in detail here. More preferably, the alloying treatment is carried out in an activation atmosphere under conditions of a temperature of 600 to 625°C and a pressure of 0.56 to 0.73 MPa for 1.5 to 7 hours, and then the temperature is lowered to 150 to 200°C at a rate of 55 to 75°C / min.

[0103] The method for producing the second composite membrane may include the steps of: (I) placing a palladium membrane or the above-mentioned alloyed material (palladium-based composite alloy material E) in a solution containing a silicon-aluminum molecular sieve precursor, and sequentially performing hydrothermal crystallization, drying, and roasting to obtain a composite membrane precursor; and (II) supporting (or depositing) sodium-modified nano-Fe3O4 on the surface of the composite membrane precursor.

[0104] In the method for producing the second composite membrane, the solution containing the precursor of the silicon-aluminum molecular sieve preferably contains a silicon source, an aluminum source, a template agent, and water.

[0105] In the method for producing the second composite membrane, the molar ratio of the silicon source, the aluminum source, the template agent, and the water is preferably 100:(2-50):(15-65):(60-2400), more preferably 100:(5-20):(20-50):(70-1250).

[0106] In the method for producing the second composite membrane, the amount of the solution containing the precursor of the silicon-aluminum molecular sieve used is preferably 0.025 to 0.85 ml per 1 g of the palladium membrane or alloyed material.

[0107] In the second composite membrane manufacturing method, the silicon source may be a material commonly used in the art capable of providing elemental silicon, preferably at least one of silicate ester, silicate, and silicon dioxide, more preferably at least one selected from tetrabutyl orthosilicate, tetraethyl orthosilicate, sodium silicate, potassium silicate, silica sol, and water glass. The aluminum source may be a material commonly used in the art capable of providing elemental aluminum, preferably at least one of metaaluminate, aluminum oxide, aluminum salt, aluminum sol, and organoaluminum alkoxide, more preferably at least one selected from sodium metaaluminate, pseudoboehmite, aluminum sulfate, aluminum nitrate, and aluminum isopropoxide. The template agent may be at least one of tetraalkylammonium hydroxide, alkylamine, and tetraalkylammonium halide, more preferably at least one selected from tetrabutylammonium hydroxide, tetrapropylammonium hydroxide, tetraethylammonium hydroxide, triethylamine, cetyltrimethylamine bromide, and isopropylamine.

[0108] In the method for producing the second composite membrane, preferably, the hydrothermal crystallization method involves aging followed by crystallization. More preferably, the aging conditions include an aging temperature of 70 to 90°C. More preferably, the aging conditions further include an aging time of 6 to 10 hours. More preferably, the crystallization conditions include a crystallization temperature of 160 to 190°C. More preferably, the crystallization conditions further include a crystallization time of 24 to 48 hours. The aging can be carried out under stirring conditions, with the stirring speed for aging preferably being 800 to 1000 rpm. The crystallization can also be carried out under stirring conditions, with the stirring speed for aging preferably being 15 to 30 rpm.

[0109] In the method for producing the second composite membrane, the drying conditions are not particularly limited, but preferably include a drying temperature of 50 to 80° C. and a drying time of 8 to 12 hours.

[0110] In the method for producing the second composite membrane, the roasting conditions preferably include a roasting temperature of 575 to 625° C. Preferably, the roasting conditions further include a roasting time of 4 to 6 hours.

[0111] In the second composite membrane manufacturing method, when the silicon source and / or aluminum source (e.g., sodium silicate, potassium silicate, water glass, sodium metaaluminate) contains Na or K, the roasted product is a sodium-type molecular sieve. Therefore, to obtain a hydrogen-type molecular sieve, the method preferably further includes a step of subjecting the roasted product to ammonium exchange. The ammonium exchange can be performed using a conventional method, which will not be described in detail here.

[0112] In the second method for producing a composite membrane, preferably, the method for depositing sodium-modified nano-Fe3O4 on the surface of the composite membrane precursor involves immersing the composite membrane precursor in a solution containing an iron source and a sodium source, followed by drying and calcination, in which the molar ratio of Na to Fe in the solution containing the iron source and the sodium source is 1:(1-10). More preferably, the concentration of Fe in the solution containing the iron source and the sodium source may be 0.01-0.86 mol / L. More preferably, the concentration of Na in the solution containing the iron source and the sodium source may be 0.01-0.55 mol / L. More preferably, the amount of the solution containing the iron source and the sodium source used is 0.01-0.05 ml per gram of the composite membrane precursor. Preferably, the iron source may be a substance commonly used in the art that can provide iron element, more preferably at least one selected from iron salts and ferrous salts, and even more preferably FeCl3, FeCl2, Fe(NO3), F e According to a particularly preferred embodiment, the iron source is at least one selected from the group consisting of SO4, NH4Fe(SO4)2, and (NH4)2Fe(SO4)2. According to a particularly preferred embodiment, the iron source is a mixture of iron ions (Fe 3+ ) source (e.g., FeCl3) and ferrous ions (Fe 2+ ) source (e.g., FeCl2).

[0113] More preferably, the sodium source may be a substance commonly used in the art that can provide elemental sodium. Preferably, the sodium source is at least one selected from sodium hydroxide and sodium salts, more preferably at least one selected from NaOH, NaHCO3, Na2CO3, and NaCl. More preferably, the pH value of the solution containing the iron source and the sodium source may be 8 to 12, preferably 9 to 11. When NaOH is used as the sodium source, the content of NaOH in the solution is such that the pH value of the solution satisfies the above range. More preferably, the soaking conditions include a soaking temperature of 15 to 85°C, more preferably 25 to 60°C, and a soaking time of 0.5 to 3.5 hours, more preferably 1 to 2 hours. More preferably, the calcination conditions include a calcination temperature of 325 to 500°C, and a calcination time of 3 to 5 hours. More preferably, the solution containing the iron source and the sodium source is aged before the composite membrane precursor is immersed in the solution containing the iron source and the sodium source, and the aging conditions include a temperature of 20 to 70°C and a time of 0.5 to 3 hours.

[0114] The methods for testing parameters such as half-width, lattice parameter, crystalline structure, thickness, average particle size, average pore size, and specific surface area according to the present invention are as described in the following test examples.

[0115] The present invention will be described in more detail below with reference to examples. In the following examples and comparative examples, the inner surface of the support is sealed with a polytetrafluoroethylene material, so that molecular sieves, nanoparticles, etc. are selectively supported only on the outer surface of the support, and the polytetrafluoroethylene material is peeled off before application or performance testing. Examples A1 to A4

[0116] (1) A porous stainless steel pipe (tubular, inner diameter: 10 mm, outer diameter: 13 mm, average pore size: 0.25 μm, porosity: 65%) was used as a support. It was first immersed in absolute ethanol for 30 minutes to remove surface contaminants such as dust and oil. The surface and interior of the support were then rinsed with deionized water, placed in warm water, and a vacuum pump was used to remove any remaining ethanol in the channels. Finally, the support was placed in an oven and dried at 423 K for 4 hours. Following Faraday's law, Pd and Au were deposited on the support using electroplating. The molar ratio M of Pd to Au is shown in Table 2, and the effective membrane area was 25 cm. 2 Here, the electroplating method is as follows: the conductive layer support is the working electrode, the platinum electrode (Pd plating) and the ruthenium / titanium oxide composite electrode (RuO2 / TiO2) (Au plating) are the counter electrodes, and the saturated calomel electrode is the reference electrode. At a temperature of 30°C, the metal ions (Pd 2+ , Au 3+ The concentrations of ammonium tetrachloropalladate (II) ((NH4)2PdCl4) solution at a rate of 1-2 ml / min, 0.01 mol / L chloroauric acid (HAuCl4) solution at a rate of 0.5-1.5 ml / min, ethylenediamine (EDA, 99%, analytical grade) at a rate of 0.1 ml / min, ethylenediaminetetraacetic acid disodium salt (EDTA-2Na, 99%, analytical grade) at a rate of 0.05 ml / min, and bipyridine (C) were used to perform the electroplating experiments. The operating voltage range was -0.60 V to -0.90 V, the scan rate was 0.0075 V / s, the scan period was 1000, and the sensitivity was 0.0001 A / V. Simultaneously, during the electroplating process, a plunger-type constant current pump was used to pump the plating solution containing 0.05 mol / L ammonium tetrachloropalladate (II) ((NH4)2PdCl4) solution at a rate of 1-2 ml / min, 0.01 mol / L chloroauric acid (HAuCl4) solution at a rate of 0.5-1.5 ml / min, ethylenediamine (EDA, 99%, analytical grade) at a rate of 0.1 ml / min, ethylenediaminetetraacetic acid disodium salt (EDTA-2Na, 99%, analytical grade) at a rate of 0.05 ml / min, and bipyridine (C). 10H8N2 (99%, analytical grade) was added at a rate of 0.01 ml / min. The plating solution was vigorously stirred (1000 r / min) during the addition of the above solution. Every 30 min of electroplating, the working electrode, washed with distilled water, was immersed in a 0.05 mol / L phosphoric acid (H3PO4) solution and a 0.05 mol / L dipotassium hydrogen phosphate (K2HPO4) solution for 10 min each. After the cyclic voltammetry program was completed, the working electrode was treated in distilled water at 95 °C for 15 min before being removed. The support on which Pd and Au were deposited was subjected to a high-temperature alloying treatment. The alloying treatment method was as follows: In an activating atmosphere, treatment was performed at a temperature of T1 and a pressure of P for a predetermined time (t), and then the temperature was lowered to T2 at a rate of V. The gas providing the activation atmosphere contains H2 and N2, the volume ratio of H2 to N2 is R1, the amount of gas used to provide the activation atmosphere is P, and the pressure of the alloying process is P. The details of each parameter are shown in Table 2. (2) The alloyed material obtained in step (1) was added to a ZSM-5 molecular sieve precursor solution, followed by hydrothermal crystallization (aging and crystallization were performed sequentially), drying, and roasting to obtain a composite membrane precursor. The molar ratio R2 of silicon source, aluminum source, template agent, and water, as well as the conditions for each step, are shown in Table 2. In the ZSM-5 molecular sieve precursor solution, tetrapropylammonium hydroxide (TPAOH) was the template agent, tetrabutyl orthosilicate (TEOS) was the silicon source, and sodium metaaluminate was the aluminum source. The amount of silicon-aluminum molecular sieve precursor solution used was 0.5 ml per 1 g of alloyed material. (3) The surface of the composite film precursor was silanized using a silanization reagent (Table 2) to obtain a composite film. The silanization step involved silanizing the composite film for 45 min in a chemical vapor deposition furnace under constant temperature, pressure, vacuum, and inert purge gas conditions. The silanization conditions were: temperature 55°C, system pressure maintained at 25 kPa using a vacuum pump (atmospheric pressure 101.325 kPa). The inert purge gas was N2, with a flow rate of 35–75 ml / min. The silanization reagent was analytical grade. 5 ml of the reagent was weighed out for 1 g of the composite film precursor and placed in a quartz boat, with the quartz boat positioned on both the front and back of the sample. Example A5

[0117] The same procedure as in Example A1 was carried out, except that the molar ratio of Pd to Au was changed to 1:1. Example A6

[0118] The same procedure as in Example A1 was carried out, except that the molar ratio of Pd to Au was changed to 1:0.2. Example A7

[0119] The same procedure as in Example A1 was carried out, except that the gases providing the activation atmosphere were changed to hydrogen gas and ammonia gas, the volume ratio of the two was set to 2.5:1, and the treatment time t in the activation atmosphere was set to 3 hours. Example A8

[0120] The same procedure as in Example A2 was carried out, except that the gases providing the activation atmosphere were changed to hydrogen gas and hydrazine, the volume ratio of the two was set to 3:1, and the treatment time t in the activation atmosphere was set to 2.5 hours. Example A9

[0121] The same procedure as in Example A3 was carried out, except that the gas providing the activation atmosphere was changed to hydrogen and phosphine, the volume ratio of the two was 3.5:1, and the treatment time in the activation atmosphere was t=2 hours. Example AD1

[0122] The same procedure as in Example A1 was carried out, except that the gas providing the activation atmosphere was N2 only. Example AD2

[0123] The procedure was the same as in Example A1, except that the gas providing the activating atmosphere was H2 only. Example AD3

[0124] The procedure was the same as in Example A1, except that the only gas providing the activation atmosphere was argon. Example AD4

[0125] The same procedure as in Example A1 was carried out, except that the gases providing the activation atmosphere were hydrogen gas and CO2 (volume ratio 1:1). Example A10

[0126] The same procedure as in Example A7 was repeated, except that a molybdenum oxide deposition step was performed on the product obtained in step (3). Specifically, the resulting silanized material was placed in a high-pressure hydrothermal synthesis reactor lined with PTFE (polytetrafluoroethylene), and a mixture of (NH4)6Mo7O2·4H2O, (NH4)2CO3, N2H4·H2O, and LiOH was added. The molar ratio of each of the above substances was 1:2:5:3, and the molar concentration of (NH4)6Mo7O2·4H2O was 0.075 mol / L. After hydrothermal synthesis in a rotary oven at 200 °C for 36 h, a uniform layer of MoO2 nanoparticles was obtained on the surface of the material. A scanning electron microscope image of the resulting molybdenum oxide nanoparticles is shown in Figure 7. Example A11

[0127] The procedure was the same as in Example A7, except that a molybdenum oxide deposition step was performed on the product obtained in step (3). Specifically, the resulting silanized material was placed in a high-pressure hydrothermal synthesis reactor lined with PTFE (polytetrafluoroethylene), and a mixture of (NH4)6Mo7O2·4H2O, (NH4)2CO3, N2H4·H2O, and LiOH was added. The molar ratio of each of the above materials was 1:3:7.5:4.5, and the molar concentration of (NH4)6Mo7O2·4H2O was 0.05 mol / L. After hydrothermal synthesis in a rotary oven at 200 °C for 36 h, a uniform layer of MoO2 nanoparticles was obtained on the surface of the material. Example A12

[0128] The procedure was the same as in Example A7, except that a tungsten oxide deposition step was performed on the product obtained in step (3). Specifically, the resulting silanized material was placed in a high-pressure hydrothermal synthesis reactor lined with PTFE (polytetrafluoroethylene) material, and a mixture of Na2WO4·2H2O, H2O, and HCl was added. The molar ratio of each of the above materials was 1:50:20, and the concentration of Na2WO4·2H2O was 0.03 mol / L. The mixture was vigorously stirred to form a uniform suspension, which was then hydrothermally synthesized in a rotary oven at 180 °C for 24 hours. A uniform layer of WO3 nanoparticles was obtained on the surface of the material. Example AD5

[0129] The same procedure as in Example A1 was carried out, except that the temperature was decreased to temperature T2 at a rate of V=5° C. / min. Example AD6

[0130] The same procedure as in Example A1 was carried out, except that the alloying treatment temperature was T1=700°C. Example AD7

[0131] The alloying treatment was carried out in the same manner as in Example A1, except that the pressure P in the alloying treatment was set to 0.1 MPa.

[0132] [Table 2] [Examples E1 to E4]

[0133] (1) A porous stainless steel pipe (tubular, inner diameter: 10 mm, outer diameter: 13 mm, average pore size: 0.25 μm, porosity: 65%) was used as a support. It was first immersed in absolute ethanol for 30 minutes to remove surface contaminants such as dust and oil. The surface and interior of the support were then rinsed with deionized water, placed in warm water, and a vacuum pump was used to remove any remaining ethanol in the channels. Finally, the support was placed in an oven and dried at 423 K for 4 hours. Following Faraday's law, Pd, Cu, and Ag were deposited on the support using electroplating. The atomic moles (M) of Pd, Cu, and Ag are shown in Table 3. The effective membrane area was 50 cm. 2 Here, the electroplating method is as follows: the conductive layer support is the working electrode, the platinum electrode (Pd plating), the waveguide with a copper content of 99.999% (Cu plating), and the silver electrode (Ag plating) are the counter electrodes, and the saturated calomel electrode is the reference electrode. At a temperature of 30°C, the metal ions (Pd 2+ , Cu 2+ , Ag + The concentration of HCl was 0.01–0.1 mol / L, and the electroplating experiments were performed by cyclic voltammetry. The operating voltage range was −0.60 V to −0.90 V, the scan rate was 0.0075 V / s, the scan period was 1000, and the sensitivity was 0.0001 A / V. At the same time, during the electroplating process, a plunger-type constant current pump was used to pump the following into the plating solution: 0.05 mol / L ammonium tetrachloropalladate (II) ((NH4)2PdCl4) solution at a rate of 1-2 ml / min, 0.075 mol / L copper nitrate (Cu(NO3)2) solution at a rate of 0.5-1.5 ml / min, 0.05 mol / L silver nitrate (AgNO3) solution at a rate of 0.25-1 ml / min, ethylenediamine (EDA, 99%, analytical grade) at a rate of 0.1 ml / min, ethylenediaminetetraacetic acid disodium salt (EDTA-2Na, 99%, analytical grade) at a rate of 0.05 ml / min, and bipyridine (C 10H8N2 (99%, analytical grade) was added at a rate of 0.01 ml / min. The plating solution was vigorously stirred (1000 r / min) during the addition of the above solution. Every 30 min of electroplating, the working electrode, washed with distilled water, was immersed in a 0.05 mol / L phosphoric acid (H3PO4) solution and a 0.05 mol / L dipotassium hydrogen phosphate (K2HPO4) solution for 10 min each. After the cyclic voltammetry program was completed, the working electrode was treated in distilled water at 95 °C for 15 min before being removed. The support on which Pd, Cu, and Ag were deposited was subjected to a high-temperature alloying treatment. The alloying treatment method was as follows: In an activating atmosphere, treatment was performed at a temperature of T1 and a pressure of P for a predetermined time (t), and then the temperature was lowered to T2 at a rate of V. The gas providing the activation atmosphere contains H2 and N2, the volume ratio of H2 to N2 is R1, the amount of gas used to provide the activation atmosphere is P, and the pressure of the alloying process is P. The details of each parameter are shown in Table 3. (2) The alloyed material obtained in step (1) was added to a HZSM-5 molecular sieve precursor solution, followed by hydrothermal crystallization (aging and crystallization performed sequentially), drying, and roasting. Ammonium exchange was then performed using ammonium nitrate (NH4NO3) to obtain a composite membrane precursor. The silicon source, aluminum source, template agent, and water molar ratio R2, as well as the conditions for each step, are listed in Table 3. For the HZSM-5 molecular sieve precursor solution, tetrapropylammonium hydroxide was the template agent, tetrabutyl orthosilicate (TEOS) was the silicon source, and sodium metaaluminate was the aluminum source. The amount of silicon-aluminum molecular sieve precursor solution used was 0.25 ml per 1 g of alloyed material. The specific method of ammonium exchange is as follows: 0.5 mol / L ammonium nitrate solution (NH4NO3) is used as an ion exchanger to exchange Na + The roasted product to be exchanged was immersed in the ion exchanger at 1.5 times the input amount and stirred at 80°C, atmospheric pressure, and 50 r / min for 2 hours. After ion exchange, the sample was baked in an oven at 100°C for 6 hours. The baked sample was immersed in the ion exchanger, and the above procedure was repeated once. (3) Sodium-modified nano-Fe3O4 was deposited on the surface of the composite membrane precursor to obtain a composite membrane. The steps for depositing sodium-modified nano-Fe3O4 were as follows: A mixed solution of FeCl3 and FeCl2 was prepared using FeCl3·6H2O and FeCl2·4H2O in a molar ratio of 2.0. The pH was adjusted with 0.1 mol / L NaOH to obtain a solution containing iron and sodium sources. The solution was aged at a stirring speed of 500 r / min to obtain a soaking solution. The composite membrane precursor was then immersed in the soaking solution, dried at 25°C and 0.002 MPa under vacuum for 10 hours to remove free water, and then calcined at 475°C for 5 hours to remove water of crystallization and the template. The molar ratio R3 of Na to Fe in the solution containing iron and sodium sources is shown in Table 3. The amount of solution containing iron and sodium sources used was 0.025 ml per 1 g of composite membrane precursor.

[0134] [Table 3] Example E5

[0135] The same procedure as in Example E1 was carried out, except that the gases providing the activation atmosphere were changed to hydrogen gas and ammonia gas, the volume ratio of the two was set to 2.5:1, and the treatment time t in the activation atmosphere was set to 4 hours. Example E6

[0136] The same procedure as in Example E1 was carried out, except that the gases providing the activation atmosphere were changed to hydrogen gas and hydrazine, the volume ratio of the two was set to 3:1, and the treatment time t in the activation atmosphere was set to 3.5 hours. Example E7

[0137] The same procedure as in Example E1 was carried out, except that the gases providing the activation atmosphere were changed to hydrogen gas and phosphine, the volume ratio of the two was set to 3.5:1, and the treatment time t in the activation atmosphere was set to 1.5 hours. Example ED1

[0138] The procedure was the same as in Example E1, except that the only gas providing the activation atmosphere was N2. Example ED2

[0139] The procedure was the same as in Example E1, except that the only gas providing the activating atmosphere was H2. Example ED3

[0140] The same procedure as in Example E1 was carried out, except that the gas providing the activation atmosphere was argon gas only. Example ED4

[0141] The same procedure as in Example E1 was carried out, except that the gases providing the activation atmosphere were hydrogen gas and CO2 (volume ratio 1:1). Example ED5

[0142] The same procedure as in Example E1 was carried out, except that the temperature was decreased to a temperature T2 at a rate of V=5° C. / min. Example ED6

[0143] The same procedure as in Example E1 was carried out, except that the alloying treatment temperature T1 was set to 700°C. Example ED7

[0144] The alloying treatment was carried out in the same manner as in Example E1, except that the pressure P of the alloying treatment was set to 0.1 MPa. Example ED8

[0145] The same procedure as in Example E1 was carried out, except that the atomic molar ratio of Pd, Cu, and Ag was M=100:500:500. Example ED9

[0146] The same procedure as in Example E1 was carried out, except that the atomic molar ratio of Pd, Cu, and Ag was M=100:0.5:0.5. Example E8

[0147] The same procedure as in Example A7 was carried out, except that Pd and Cu were deposited on the support in a weight ratio of 1:1.3. Example E9

[0148] The same procedure as in Example A7 was carried out, except that Pd, Cu and Ni were deposited on the support in a weight ratio of 1:1:0.6. [Test example]

[0149] (I) The materials (i.e., palladium-based composite alloy materials) obtained by the alloying treatment in step (1) of each example and comparative example were characterized as follows, and the crystal structure parameters of the obtained palladium-based composite alloy materials are shown in Tables 4 to 8. The crystal phase structure of the palladium-based composite alloy material was analyzed using an X'PertPRO / PANalytical automatic X-ray diffractometer manufactured by Philips in the Netherlands. α The scanning range of the diffraction angle 2θ was 10 to 90°C. ° The interplanar spacing of the sample was calculated using the Bragg equation.

[0150]

number

[0151] The crystal structure of palladium-based composite alloy materials was examined at the European Synchrotron Radiation Center (beam BM25A) in France, with higher resolution, synchrotron radiation λ = 0.0618886 nm or 0.077449 nm, tube pressure 10.0335 keV or 20.0335 keV. 2 The sample was placed in a quartz capillary tube with a diameter of 2 mm, and both ends of the tube were sealed with quartz wool. The quartz capillary tube was then placed on a rotatable sample stage (ensuring uniform temperature and a larger radiation exposure area). The test temperature range was 298–473 K (heated by a hot air blower), and the pressure range was 10. -4The pressure was adjusted to about 130 kPa, and hydrogen gas was first introduced as the test atmosphere. After 30 minutes of treatment, the sample was evacuated, and then helium gas was introduced as a protective gas for measurement. The test method for the lattice parameters of palladium-based composite alloy materials is as follows: Combined with the above in-situ XRD test, the unit cell parameters of palladium-based alloy materials can be obtained (expressed as both the three unit cell constants a, b, c and the intersection angles α, β, γ between the three edges of the unit cell), and calculated using 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 ) 0.5 The crystal plane spacing (d1d2d3) of the corresponding characteristic crystal plane was obtained by conversion using the formula: For example, the PdAu alloy material obtained in the present invention belongs to a face-centered cubic close-packed (FCC) structure, and its characteristic crystal planes include (110), (111), (220), (311), and (222). In addition, the X-ray diffraction results obtained a series of different characteristic crystal plane ratios (intensities corresponding to the different measured crystal planes). For example, in the PdAu alloy material obtained in the present invention, the (110) plane has a 2θ=40 o ±1 o The (111) plane corresponds to the characteristic peak at 2θ=46 o ±1 o The (220) plane corresponds to the characteristic peak at 2θ=69 o ±1 o The (311) plane corresponds to the characteristic peak at 2θ=83 o ±1 o The (222) plane corresponds to the characteristic peak at 2θ=87 o ±1 o This corresponds to the characteristic peak in the crystal plane. The lattice parameter k of the corresponding material was obtained by combining and converting the peak intensity of the characteristic crystal planes mentioned above through HighScorePlus analysis software.

[0152] The thickness of the palladium-based composite alloy material was measured using a scanning electron microscope (model: JSM-7610F) and the thickness of the alloy film was measured according to the scale bar corresponding to the magnification. The surface flatness of the obtained palladium-based composite alloy material was also observed using a scanning electron microscope, and the results show that the surface of the palladium-based composite alloy material produced by the present invention is smooth and defect-free.

[0153] The half-width of the palladium-based composite alloy material was measured as follows: The radian value of the half-width was obtained from the XRD spectrum test results using HighScorePlus analysis software. The XRD spectra of the palladium-based composite alloy materials obtained in Examples A1 and E8 are shown in Figures 2a and 2b, respectively.

[0154] (II) The composite membranes (materials obtained before oxide deposition) obtained in each example and comparative example were subjected to solid-phase exfoliation treatment to exfoliate the molecular sieves and evaluate their properties. The method for evaluating properties is as follows. The relevant structural parameters of the molecular sieves attached to the surface of the palladium-based composite alloy material were obtained, and are specifically listed in Tables 4 and 6.

[0155] The molecular sieves were analyzed using an Empyrean X-ray diffractometer manufactured by Malvern-Panalytical. Test conditions were: Cu target, Ka radiation, Ni filter, 40 kV tube voltage, 40 mA tube current, scintillation counter, 0.0131° step size, 5-35° scan range, 2.5° / min scan rate. The results indicated that the molecular sieves were ZSM-5 silicon-aluminum molecular sieves with a channel structure consisting of intersecting double ten-membered rings (MFI structure). (Figure 2c shows the XRD spectrum of the molecular sieve obtained in Example A1. The four characteristic peaks between 23° and 25° indicate that this material has a channel structure consisting of intersecting double ten-membered rings, which is consistent with the characteristics of ZSM-5 silicon-aluminum molecular sieves. The XRD spectra of the molecular sieves in each example were similar to Figure 2c, indicating that all the molecular sieves obtained were ZSM-5 silicon-aluminum molecular sieves.)

[0156] Testing method for molecular sieve specific surface area and average pore diameter: This was performed using a Micromeritics ASAP 2020 physical adsorption apparatus from the United States. The samples were subjected to high vacuum treatment at 363K and 573K for 1h and 3h, respectively, and then adsorbed at a constant temperature of 77K using N2 as the adsorbate. The BET specific surface area was calculated from the N2 adsorption isotherm combined with the BET equation. The average pore diameter was calculated from the desorption branch of the N2 adsorption isotherm using the BJH method.

[0157] Test method for molecular sieve crystallinity: Using a conventional X-ray diffraction instrument, measurements were performed at a tube voltage of 40 kV, a tube current of 40 mA, and a scan rate of 2.5° / min. The diffraction patterns of the samples were recorded within the 2θ range of 5° to 35°. A ZSM-5 sample manufactured by Aladdin Biochemical Technology Co., Ltd. (Shanghai) M196697 was used as the reference sample, and its relative crystallinity was set to 100. The peak intensities of the characteristic diffraction peaks at 2θ = 7.96°, 8.83°, 23.18°, 23.99°, and 24.45° of each sample were calculated and compared with the sum of the peak intensities of the reference sample to calculate the relative crystallinity of each sample.

[0158] Test method for average particle size of molecular sieve: The microscopic morphology of the molecular sieve in the sample was observed under a transmission electron microscope, and the diameter was measured according to the scale bar. The corresponding particle size distribution was calculated by averaging multiple samples by mathematical statistical methods.

[0159] The thickness of the molecular sieve was determined by measuring the thickness of the molecular sieve membrane according to the scale bar corresponding to the magnification obtained from the results of a scanning electron microscope.

[0160] Infrared testing method for hydroxyl groups of molecular sieves: Fourier transform infrared spectra of samples were recorded using a Bruker-INVENIO R and Tensor 27 infrared spectrometer with KBr as the background. The samples were placed in a flow cell and evacuated at 823 K for 2 h. The wavelengths were measured from 4000 to 650 cm. -1 The hydroxyl group content in the range was determined by a total of 32 scans at wavenumber 3500 cm in the corresponding spectrum. -1 The peak around 3750 cm represents the relative content of nested hydroxyl groups in the molecular sieve. -1 The peak around represents the relative content of terminal hydroxyl groups in the molecular sieve. The degree of reduction in the total amount of hydroxyl groups before and after hydrophobic treatment can be determined from the change in peak area. Here, the larger the peak area at the corresponding position, the higher the hydroxyl group content, which can qualitatively describe the hydrophobic properties of the membrane material. (The results of the infrared characteristic evaluation of the hydroxyl groups before and after treatment with the silanization reagent in Example A1 are shown in Figure 5 (the dotted line indicates before hydrophobic treatment, and the solid line indicates after hydrophobic treatment). After hydrophobic treatment, the peak at a wavenumber of 3500 cm -1 and wave number 3750 cm -1 The peak area around the peak area is significantly reduced. This indicates that the hydrophobic treatment method of the present invention can effectively reduce the number of hydroxy groups on the surface of the membrane material and improve the hydrophobicity of the membrane material. The results of the infrared characterization of the hydroxy groups before and after treatment with the silanization reagent in each example are similar to those in Figure 5.

[0161] NMR test method for silicon molecular sieve: VARIAN VNMRS 400WB nuclear magnetic resonance spectrometer, (CH3)3Si(CH2)3SO3Na was used as the chemical shift standard, and the frequency was 79.43 MHz by the single pulse method with a spinning speed of 3 kHz and a cycle delay of 60 s. 29 The Si MAS nuclear magnetic resonance spectrum was measured. In the corresponding spectrum, the peaks with chemical shifts around -113 ppm and -103 ppm represent the relative content of the silicon molecular sieve framework structures Q4:Si(OSi)4 and Q3:Si(OSi)3OH, respectively. The ratio of Q4 / Q3 represents the relative content of silanol groups in the molecular sieve. The larger the Q4 / Q3 value, the fewer the number of silanol groups and the better the hydrophobicity of the material. For details, see the corresponding values of "Silanol Groups (Q4 / Q3)" in Table 4. The degree of reduction in the relative content of silanol groups can be determined based on the change in the ratio before and after hydrophobization treatment (as shown in Figure 6 (dotted line: before hydrophobization treatment, solid line: after hydrophobization treatment), the nuclear magnetic resonance characterization results in an increase in Q4 / Q3 after hydrophobization treatment, which indicates that the hydrophobization method of the present invention can effectively reduce the number of silanol groups on the surface of the membrane material and improve the hydrophobicity of the membrane material).

[0162] (III) Comprehensive test of composite membrane The liquid contact angles of the obtained composite membranes were tested as follows. Using a data physics Contact Angle System OCA 25 device, various liquids were used as media. The contact states of the various liquids and the composite membrane were captured using a built-in high-speed camera, and the captured images were processed using built-in software to obtain contact angle information. Figures 3 and 4 show the contact angle experiments between the composite membrane of Example A1 and various liquids before and after hydrophobic treatment, respectively.

[0163] E act (Hydrogen permeation activation energy, unit: kJ mol -1The test method for this is as follows: The hydrogen gas permeation rate was measured at a temperature between 573K and 773K with a transmembrane pressure difference of 0.1MPa, and the Arrhenius equation J H2 =J H2 o exp(-E act / RT), where J H2 is the hydrogen gas permeation / diffusion rate, J H2 o is the hydrogen gas permeation and diffusion coefficient, R is the gas constant, and T is the absolute temperature. The higher the hydrogen permeation activation energy, the higher the mass transfer resistance of hydrogen gas in the composite membrane material, making it more difficult for hydrogen gas to permeate and diffuse through the composite membrane. H2 (Hydrogen gas permeation / diffusion rate, unit: mol m -2 ·s -1 The test method is to measure the volume (L) of hydrogen gas passing through a palladium composite membrane in 1 minute at 20°C and a transmembrane pressure difference of 0.1 MPa, and calculate the hydrogen permeability (mol m -2 ·s -1 ) normalized by the membrane area (square meters). N2 (Nitrogen gas permeation / diffusion rate, unit: mmol m -2 ·s -1 The test method is to measure the volume (ml) of nitrogen gas passing through a palladium composite membrane in 1 minute at 20°C and a transmembrane pressure difference of 0.1 MPa, and then calculate the hydrogen permeation rate (mmol m -2 ·s -1 ) normalized by the membrane area (square meters).

[0164] Since the dynamic molecular diameter of hydrogen gas is smaller than the average pore diameter of the molecular sieve membrane, the E act , J H2 , J N2 is the E of palladium-based composite alloy materials act , J H2 , J N2 is equal to.

[0165] The elemental composition of the composite films was analyzed using a combination of X-ray fluorescence (XRF) and inductively coupled plasma optical emission spectroscopy (ICP-OES), and the valence states of the elements were analyzed and determined using X-ray photoelectron spectroscopy (XPS).

[0166] The morphology of the oxide nanoparticles was observed using a scanning electron microscope (SEM), and the average particle size was calculated. The test results are shown in Tables 4 to 8.

[0167] [Table 4]

[0168] [Table 5]

[0169] [Table 6]

[0170] [Table 7]

[0171] [Table 8] (IV) Application Test

[0172] The performance of the composite membranes prepared in the above examples and comparative examples in reformed hydrogen production is tested.

[0173] (a) The Pd and Au composite membrane (tubular membrane) prepared above and a CuO / ZnO / Al2O3 (Cu, Zn, and Al molar ratio 1:1:0.23) steam reforming catalyst were packaged together in a membrane reactor. The steam reforming catalyst was packed inside the tubular membrane with a loading volume of 5 ml (see Figure 8). After sealing with a stainless steel plug equipped with a graphite gasket 5, it was packed into a cylindrical stainless steel reactor 6 with a length of 500 mm and an inner diameter of 45 mm (see Figure 8 for details). The conditions were 320°C, 0.35 MPa, and a gas volumetric space velocity of 10,000 h -1The feed gas (feed) was introduced at a molar ratio of CHOH:HO = 1:4, and a reforming hydrogen production reaction was carried out under the conditions described above. The product and exhaust gas were detected as follows: The hydrogen product (permeate) from the permeate side was analyzed online using a Shanghai Tianmei SCION-456 gas chromatograph equipped with FID and PDHID detectors. Changes in product distribution and hydrogen gas purity were monitored in real time. The exhaust gas (retentate) from the retentate side was analyzed online using a Shanghai Tianmei SCION-456 gas chromatograph equipped with TCD and FID detectors. Based on the detection results, the methanol conversion rate, hydrogen gas selectivity, and hydrogen gas recovery rate were calculated. The product was tested every 5 hours. The continuous operation time was measured when the methanol conversion rate fell to 90% of its initial value. The experimental values measured after reaching the initial value and the continuous operation time are shown in Table 9. Here, the amount of hydrogen gas produced by the reaction is the sum of the amounts of hydrogen gas on the retention side and permeation side, and the calculation formulas for methanol conversion, hydrogen gas selectivity, and hydrogen gas recovery rate are as follows:

[0174] Methanol conversion rate (C CH3OH ) = (amount of carbon dioxide + amount of carbon monoxide) / amount of methanol introduced into the reactor Selectivity for hydrogen gas (S H2 ) = amount of hydrogen gas produced by the reaction / (amount of hydrogen gas produced by the reaction + amount of carbon monoxide produced by the reaction) Hydrogen gas recovery rate (R H2 ) = Amount of hydrogen gas permeating through the permeation side / Amount of hydrogen gas produced by the reaction

[0175] Hydrogen-nitrogen selectivity (α(H2 / N2)) refers to the ratio of the hydrogen gas permeation and diffusion rate through defects in the palladium membrane to the nitrogen gas permeation and diffusion rate through defects. The larger this value, the more stable the mechanical strength of the palladium membrane is and the fewer defects there are in the composite membrane material. Specifically, the hydrogen gas permeation and diffusion rate (J H2) and the permeation and diffusion rate (J N2 ) and the equation α(H2 / N2)=J H2 / J N2 The above measurement methods were combined to perform the measurement.

[0176] The carbon deposition amount test method is a thermogravimetric analysis method in which the test sample is heated in an air atmosphere from room temperature to 800°C at a rate of 5°C / min, and the amount of carbon deposition is obtained from the change in the mass of the sample before and after the reaction.

[0177] [Table 9]

[0178] (b) Hydrogen production by steam reforming was carried out in the same manner as in step (a), except that 50 ppm of hydrogen sulfide (HS) was added to the feed gas. The results are shown in Table 10.

[0179] [Table 10]

[0180] (c) The retained exhaust gas (CO2 and H2 in a volume ratio of 1:4) obtained using the composite membrane A1 in step (a) was introduced into another reactor, where the hydrocarbons in the gasoline fraction and some of the unreacted CO2 were obtained through the catalytic action of Na-Fe3O4 / HZSM-5 in another composite membrane (containing Pd, Cu, and Ag). The specific operation is as follows:

[0181] The exhaust gas (CO and H in a volume ratio of 1:4, the volumetric space velocity of the mixed gas was 5000 h ) obtained by using the composite membrane A1 in step (a) on the retention side. -1) was introduced at 350°C and a pressure of 0.3 MPa. After separation through another composite membrane, pure hydrogen gas was obtained from the permeate side, and a mixture of some hydrogen gas and carbon dioxide was obtained from the retentate side. The Na-Fe3O4 / HZSM-5 composite membrane catalyzed the separation of hydrocarbons (gasoline fraction) and some incompletely reacted CO2. The permeate hydrogen gas product was analyzed online using a Shanghai Tianmei gas chromatograph SCION-456 equipped with FID and PDHID detectors to monitor changes in hydrogen gas purity in real time. The retentate side composition was analyzed using an Agilent 7890B chromatograph equipped with TCD and FID detectors to detect the relative content of hydrocarbon components (gasoline fraction), as well as the content of incompletely reacted hydrogen gas, carbon dioxide, and other feedstocks. Based on the test results, the carbon dioxide conversion, selectivity for hydrocarbons (gasoline fraction), and hydrogen gas recovery were calculated. The products were measured every 5 h. The continuous operation time when the carbon dioxide conversion rate dropped to 90% of the initial value was recorded as the continuous operation time, and the initial reaction value and the experimental measurement values after reaching the continuous operation time are shown in Table 11. The hydrocarbons that are the gasoline fraction in the mixed components are concentrated and absorbed in the light naphtha absorbent, and if the concentration of CO2 remaining after the reaction on the retention side is sufficiently high, the carbon dioxide component is further concentrated and stored after compression. Carbon dioxide conversion rate (C CO2 ) = amount of carbon dioxide at reactor outlet / (amount of carbon dioxide at reactor inlet - amount of carbon dioxide at reactor outlet) Selectivity of hydrocarbons in the gasoline fraction (S gasline ) = C5 to C at the reactor outlet 12 Total amount of hydrocarbons / Total amount of hydrocarbons at reactor outlet Hydrogen gas recovery rate (R H2 ) = Amount of hydrogen gas permeating through the permeation side / Amount of hydrogen gas introduced into the reaction Hydrogen-nitrogen selectivity (α(H2 / N2)) refers to the ratio of the hydrogen gas permeation and diffusion rate through defects in the palladium membrane to the nitrogen gas permeation and diffusion rate through defects. The larger this value, the more stable the mechanical strength of the palladium membrane is and the fewer defects there are in the composite membrane material. Specifically, the hydrogen gas permeation and diffusion rate (J H2 ) and the permeation and diffusion rate (J N2 ) and the equation α(H2 / N2)=J H2 / J N2 The above measurement methods were combined to perform the measurement.

[0182] [Table 11]

[0183] Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited thereto. Within the scope of the technical idea of the present invention, various simple modifications can be made to the technical solutions of the present invention, including combining various technical features in other appropriate ways. These simple modifications and combinations should also be considered as the disclosure of the present invention, and all fall within the protection scope of the present invention. [Brief explanation of the drawings]

[0184] [Figure 1] Schematic diagram of hydrogen production by alcohol-based steam reforming over a hydrophobized ZSM-5 / PdAu composite membrane. [Figure 2] 2a to 2c are XRD characteristic spectra of the structures of the palladium-based composite alloy material and the molecular sieve. [Figure 3] FIG. 1 is an experimental diagram of contact angles between a composite film and various liquids before hydrophobization treatment. [Figure 4] 1 is an experimental diagram of contact angles between composite films and various liquids after hydrophobic treatment. [Figure 5] 1 shows the results of infrared characteristic evaluation of hydroxyl groups before and after hydrophobic treatment. [Figure 6] The results of NMR characteristic evaluation before and after hydrophobic treatment are shown. [Figure 7] 1 shows a scanning electron microscope (SEM) image of the surface of the composite membrane after loading MoO2 nanoparticles. [Figure 8] FIG. 1 is a schematic structural diagram of the catalyst and composite membrane packaged and placed in a tubular reactor.

Claims

1. A palladium-based composite alloy material comprising Pd and a Group IB metal element, wherein the half-width of at least one characteristic peak within a 2θ range of 5° to 90° in an XRD spectrum is 0.1745 or less.

2. 2. The palladium-based composite alloy material according to claim 1, wherein in the XRD spectrum, the half-width of all characteristic peaks within the 2θ range of 5° to 90° is 0.1745 or less.

3. 3. The palladium-based composite alloy material according to claim 1, wherein in an XRD spectrum, the half-width of all characteristic peaks within a 2θ range of 5° to 90° is 0.01 or more.

4. In the XRD spectrum, the half width of the characteristic peak at 2θ = 40 ° ± 1 ° is in the range of 0.017 to 0.02, or the half width of the characteristic peak at 2θ = 46 ° ± 1 ° is in the range of 0.017 to 0.034, or the half width of the characteristic peak at 2θ = 69 ° ± 1 ° is in the range of 0.029 to 0.036, or the half width of the characteristic peak at 2θ = 83 ° ± 1 ° is in the range of 0.031 to 0.039, or the half width of the characteristic peak at 2θ = 87 ° ± 1 ° is in the range of 0.032 to 0.

041. The palladium-based composite alloy material according to claim 1, 2 or 3.

5. In the XRD spectrum, the half width of the characteristic peak at 2θ = 43 ° ± 1 ° is in the range of 0.017 to 0.041, the half width of the characteristic peak at 2θ = 53 ° ± 1 ° is in the range of 0.024 to 0.055, the half width of the characteristic peak at 2θ = 62 ° ± 1 ° is in the range of 0.036 to 0.066, the half width of the characteristic peak at 2θ = 70 ° ± 1 ° is in the range of 0.047 to 0.068, and the half width of the characteristic peak at 2θ = 79 ° ± 1 ° is in the range of 0.051 to 0.

074. The palladium-based composite alloy material according to claim 1, 2 or 3.

6. The IB group metal element is Au, and in the XRD spectrum of the palladium-based composite alloy material, the half width of a characteristic peak at 2θ=40°±1° is FWHM １ , the half-width of the characteristic peak at 2θ = 46° ± 1° is FWHM ２ , the half-width of the characteristic peak at 2θ = 69° ± 1° is FWHM ３ , the half-width of the characteristic peak at 2θ = 83° ± 1° is FWHM ４ , the half-width of the characteristic peak at 2θ = 87° ± 1° is FWHM ５ Then, the following formula I is satisfied: FWHM ｘ = (FWHM ｘ－１ + FWHM ｘ＋１ ) / 2 ± W Formula I 6. The palladium-based composite alloy material according to claim 1, wherein x is 2, 3, or 4, and W is 0.0003 to 0.0064.

7. The palladium-based composite alloy material according to any one of claims 1 to 6, wherein the lattice parameter k of the palladium-based composite alloy material is 0.3836 to 0.4369 nm.

8. The palladium-based composite alloy material according to any one of claims 1 to 7, wherein the lattice parameter k of the palladium-based composite alloy material is 0.4075 to 0.4289 nm.

9. The palladium-based composite alloy material has a face-centered cubic close-packed or body-centered cubic packed crystal structure, and / or the Group IB metal element is at least one of Cu, Ag, and Au; and / or the molar ratio of Pd to the IB group metal element is 1:(0.01 to 10), preferably 1:(0.1 to 1.6), more preferably 1:(0.2 to 0.8); and / or the palladium-based composite alloy material further contains Ni, and the molar ratio of Pd to Ni is 1:(0.35 to 0.65); And / or the palladium-based composite alloy material according to any one of claims 1 to 8, wherein the thickness of said palladium-based composite alloy material is 0.5 to 30 µm, preferably 5 to 15 µm.

10. A composite membrane comprising: a palladium-based composite alloy material; and a hydrophobic group-modified silicon-aluminum molecular sieve attached to a surface of the palladium-based composite alloy material, wherein the palladium-based composite alloy material is the palladium-based composite alloy material according to any one of claims 1 to 9.

11. The composite film has a water contact angle of 90° or more, preferably 105° or more, and / or the composite membrane is a tubular membrane; And / or the composite membrane according to claim 10, wherein the composite membrane further comprises a support, the palladium-based composite alloy material is attached to the support, and the thickness of the support is 0.1 to 20 mm, preferably 2 to 5 mm.

12. The hydrophobic group-modified silicon-aluminum molecular sieve ２９ In the Si MAS nuclear magnetic resonance spectrum, the peak area ratio of the peaks at chemical shifts of −113 ppm and −103 ppm is 6 to 12, and / or the silicon-aluminum molecular sieve is at least one of ZSM-5, ZSM-11, ZSM-12, ZSM-23, ZSM-34, 3A molecular sieve, 4A molecular sieve, 5A molecular sieve, SAPO-31, SAPO-34, SAPO-44, RUB-13, MCM-68, Y-type molecular sieve, and mordenite; and / or the thickness of the hydrophobic group-modified silicon-aluminum molecular sieve is 1 to 100 μm, preferably 5 to 30 μm; and / or the hydrophobic group-modified silicon-aluminum molecular sieve has a molar ratio of silicon element to aluminum element of (2 to 100):1, preferably (2.5 to 20):1, an average particle size of 60 to 380 nm, preferably 150 to 200 nm, an average pore size of 0.3 to 230 nm, preferably 1 to 18 nm, and a specific surface area of 35 to 750 m ２ / g, preferably 65 to 480 m ２ / g and a crystallinity of 90% or more, preferably 95 to 99%.

13. The method further comprises attaching Group VIB metal oxide nanoparticles to the surface of the hydrophobic group-modified silicon-aluminum molecular sieve, wherein the Group VIB metal oxide nanoparticles have an average particle size of 50 to 200 nm; 13. A composite membrane according to claim 10, 11 or 12, wherein the content of said Group VIB metal oxide nanoparticles is preferably such that the molar ratio of Group VIB metal to Pd is between 0.01 and 0.

5.

14. Use of the composite membrane of any one of claims 10 to 13 in hydrogen production by steam reforming.

15. A method for producing hydrogen by steam reforming, comprising: a step of introducing alcohol and water vapor into a first reactor provided with a first composite membrane in the presence of a catalyst to carry out a reforming reaction, the first composite membrane being the composite membrane according to any one of claims 10 to 13, the alcohol and water vapor being introduced from a side of the hydrophobic-group-modified silicon-aluminum molecular sieve close to the first composite membrane, hydrogen gas produced by the reforming reaction passing through one side of the hydrophobic-group-modified silicon-aluminum molecular sieve, permeating the first composite membrane, and being taken out of the first reactor; Optionally, the method further comprises introducing gas that does not permeate the first composite membrane into a second reactor containing a second composite membrane for capturing or converting carbon dioxide.

16. The second composite membrane is a palladium membrane and a sodium-modified nano-Fe attached to the surface of the palladium membrane. ３ O ４ and a silicon-aluminum molecular sieve carrying the compound.

17. the silicon-aluminum molecular sieve in the second composite membrane is at least one of HZSM-5, HZSM-11, HZSM-12, HZSM-23, HZSM-34, HY, HMCM-22, HBEA, and HMOR; and / or the sodium-modified nano-Fe ３ O ４ The thickness of the silicon-aluminum molecular sieve carrying the above-mentioned compound is 100 to 3750 nm, more preferably 350 to 1500 nm, and / or the silicon-aluminum molecular sieve in the second composite membrane has a molar ratio of silicon element to aluminum element of (2 to 50):1, preferably (5 to 20):1, an average particle size of 50 to 420 nm, preferably 150 to 300 nm, an average pore size of 0.25 to 225 nm, preferably 0.75 to 35 nm, and a specific surface area of 25 to 600 m ２ / g, preferably 50 to 500m ２ / g, and the crystallinity is 92% or more, preferably 96 to 99%; and / or sodium-modified nano-Fe in the second composite membrane. ３ O ４ The average particle size of the powder is 5 to 300 nm, preferably 10 to 100 nm, and / or sodium-modified nano-Fe in the second composite membrane. ３ O ４ The amount of Pd supported is set so that the molar ratio of Pd to Fe is 1: (0.001 to 0.1), preferably 1: (0.001 to 0.03), and / or sodium-modified nano-Fe in the second composite membrane. ３ O ４ The method according to claim 16, wherein the molar ratio of Na to Fe in the solution is 1:(1-10), preferably 1:(3-6).

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