CN113274891A - Zirconium carbide film for hydrogen separation and preparation method thereof - Google Patents

Abstract

The invention relates to the technical field of hydrogen purification, in particular to a zirconium carbide membrane for hydrogen separation, which comprises a dissociation layer, a diffusion layer and a recombination layer, wherein the dissociation layer, the diffusion layer and the recombination layer are sequentially stacked from top to bottom and are used for dissociating hydrogen, diffusing hydrogen atoms and recombining the hydrogen atoms, and the dissociation layer and the recombination layer are zirconium carbide films and are prepared according to the method comprising the step four.

Description

A kind of zirconium carbide membrane for hydrogen separation and preparation method thereof

technical field

The invention relates to the technical field of hydrogen purification, in particular to a zirconium carbide membrane for hydrogen separation and a preparation method thereof.

Background technique

Since high-purity hydrogen energy has the advantages of cleanness, environmental protection, automatic regeneration, high temperature and high energy, it is widely used in the fields of electronics industry, aerospace, petrochemical industry, and automobile industry, so the preparation of high-purity hydrogen with high efficiency and low cost is of great significance. The three methods of hydrogen production commonly used in industry are water electrolysis, gas reforming and hydrocarbon cracking. However, the purity of hydrogen obtained by this method is too low to be used on a large scale. Therefore, it is very important for hydrogen purification technology. . Hydrogen purification methods include pressure swing adsorption, low temperature distillation and membrane separation. Among them, membrane separation has the advantages of simple operation, resource saving, low cost and high efficiency. Therefore, the most widely used purification method in industry is membrane separation. The metal membrane separation method has the advantages of high selectivity and wide operating temperature.

Metal membrane materials for hydrogen filtration currently used in industry include: Pd alloy membrane and 5B group element alloy membrane; Pd alloy membrane has the advantages of high hydrogen permeability and independent catalytic hydrogen molecule dissociation, etc. The 5B element alloy film has the advantages of high hydrogen dissolution and low cost, but the 5B group alloy film cannot adsorb and dissociate hydrogen molecules into hydrogen atoms on the metal surface, and the hydrogen embrittlement is serious at low temperature (<350 °C). Deposition of Pd film on the surface of Group 5B metals can solve this problem, but the interdiffusion between the Pd film and the diffusion layer at high temperature leads to a decrease in hydrogen permeation performance. Therefore, we urgently need to develop a new type of hydrogen separation membrane with low cost and catalytic activity. .

In view of this, the present invention is proposed.

SUMMARY OF THE INVENTION

In view of the above defects, the present invention proposes a zirconium carbide membrane for hydrogen separation, including a dissociation layer for dissociating hydrogen, a diffusion layer for diffusing hydrogen atoms, and a For the recombination layer for recombining hydrogen atoms, both the dissociation layer and the recombination layer are zirconium carbide thin films.

Preferably, the molar ratio of Zr and C in the zirconium carbide thin film is (1-6):(1-3).

Preferably, the molar ratio of Zr and C in the zirconium carbide thin film is (1-3):1.

Preferably, the diffusion layer is made of dense material or porous material;

When the diffusion layer is a dense material, the dense material is V, Nb, Ta, Mo, Ni, Ti, Pd, Pt, V-Ni alloy, V-Cr alloy, V-Cu alloy, V-Fe alloy , V-Al alloy, V-Co alloy, V-Mo alloy, V-W alloy, V-Ti-Ni alloy, V-Fe-Al alloy, V-Mo-W alloy, Nb-Ti-Ni alloy, Nb-Ti -One of Co alloy and Nb-Mo-W alloy;

When the diffusion layer is a porous material, the porous material is porous stainless steel or porous titanium-aluminum alloy.

Preferably, the thickness of the dissociation layer is 5-500 nm, the thickness of the recombination layer is 5-500 nm, and the thickness of the diffusion layer is 20-20000 μm.

A preparation method of a zirconium carbide membrane for hydrogen separation, characterized in that, according to the following steps:

Step 1: Preprocess the diffusion layer;

Step 2: cleaning the surface of the diffusion layer with an ion beam;

Step 3: using one of magnetron sputtering, ion beam sputtering, electron beam evaporation, pulse deposition, molecular beam epitaxy and atomic layer deposition to form a dissociation layer on one side of the diffusion layer;

Step 4: forming a recombination layer on the other side of the diffusion layer by using one of magnetron sputtering, ion beam sputtering, electron beam evaporation, pulse deposition, molecular beam epitaxy and atomic layer deposition.

Preferably, in step 1, acetone and anhydrous ethanol are used to ultrasonically clean the diffusion layer for 5-15 minutes, repeating 2-3 times, then rinsed with deionized water for 1-2 minutes, and then dried.

Preferably, in step 3, a dissociation layer is formed on one side of the diffusion layer by magnetron sputtering; in step 4, a recombination layer is formed on the other side of the diffusion layer by magnetron sputtering.

Preferably, the cleaning conditions in step 2 include: the vacuum degree in the sputtering chamber is less than 10 ^-4 Pa; the temperature of the diffusion layer is 25-600°C; the negative bias voltage of the diffusion layer is 0-500V; ; Set the electron beam current 50mA, the argon flow rate 5sccm, the chamber pressure 3-8* ^10-2 Pa, and the continuous bombardment time is 5-60min;

The conditions of the magnetron sputtering in step 3 and step 4 include: the vacuum degree of magnetron sputtering is less than 10 ^-4 Pa, the temperature of the diffusion layer is 25-600° C., the negative bias voltage of the diffusion layer is 0-500V, and argon gas is introduced. The flow rate is 10-50sccm, the working pressure is 0.2-2Pa, the working power is 50-400W, and the sputtering time is 2-120min.

Application of a zirconium carbide membrane for hydrogen separation and its preparation method in hydrogen separation and/or hydrogen purification.

Compared with the prior art, the present invention has at least the following advantages:

1. The present invention combines the novel zirconium carbide hydrogen separation membrane with the diffusion layer material to replace the precious metal Pd, which greatly reduces the application cost of hydrogen separation;

2. As a new type of hydrogen separation membrane, zirconium carbide has good stability and hydrogen permeability in high temperature environment;

3. The zirconium carbide and substrate composite membrane of the present invention has better high-temperature hydrogen permeation stability than pure Pd, Pd alloy and Pd/diffusion layer composite membrane;

The novel niobium carbide hydrogen separation membrane of the present invention provides a new choice for materials and devices for realizing novel, cheap, efficient and stable hydrogen separation and purification.

Description of drawings

In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the accompanying drawings required in the description of the specific embodiments or the prior art. Obviously, the accompanying drawings in the following description The drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

Figure 1 is a schematic structural diagram of a zirconium thin film,

2 is a schematic diagram of the hydrogen permeation process of hydrogen atoms when the zirconium film is purified by hydrogen;

Figure 3 is a SEM image of a single side cross-section of a zirconium thin film;

Fig. 4 is the XRD pattern of the zirconium carbide thin film prepared in Example 1;

Fig. 5 is the variation curve of hydrogen flux with pressure obtained under different working temperatures of the zirconium thin film prepared under the sputtering power of 300W in Example 1;

Fig. 6 is the variation curve of hydrogen flux with pressure obtained under different working temperatures of the zirconium thin film prepared under the sputtering power of 200W in Example 1;

Fig. 7 is the variation curve of hydrogen flux with pressure obtained under different working temperatures of the zirconium thin film prepared under 100W sputtering power in Example 1;

Fig. 8 is the curve that the hydrogen permeation flux changes with time when the sputtering power is 300W;

in,

1- dissociation layer, 2- diffusion layer, 3- recombination layer.

Detailed ways

The following is a detailed description of several preferred embodiments of the present invention, but the present invention is not limited to these embodiments. The present invention covers any alternatives, modifications, equivalent methods and arrangements made within the spirit and scope of the present invention. In order to give the public a thorough understanding of the present invention, specific details are described in detail in the following preferred embodiments of the present invention, and those skilled in the art can fully understand the present invention without the description of these details.

Example 1

As shown in FIG. 1, a zirconium carbide membrane for hydrogen separation includes a dissociation layer 1 for dissociating hydrogen, a diffusion layer 2 for diffusing hydrogen atoms and For the recombination layer 3 for recombining hydrogen atoms, the dissociation layer 1 and the recombination layer 3 are both zirconium carbide films, and the diffusion layer 2 is a V foil with a thickness of 100 μm.

In this embodiment, the molar ratio of Zr and C in the zirconium carbide thin film is (1-6):(1-3).

In this embodiment, the molar ratio of Zr and C in the zirconium carbide thin film is (1-3):1.

In this embodiment, the molar ratio of Zr and C in the zirconium carbide film is 1:1

In this embodiment, the diffusion layer 2 is made of dense material or porous material;

When the diffusion layer 2 is a dense material, the dense material is V, Nb, Ta, Mo, Ni, Ti, Pd, Pt, V-Ni alloy, V-Cr alloy, V-Cu alloy, V-Fe Alloys, V-Al alloys, V-Co alloys, V-Mo alloys, V-W alloys, V-Ti-Ni alloys, V-Fe-Al alloys, V-Mo-W alloys, Nb-Ti-Ni alloys, Nb- One of Ti-Co alloy and Nb-Mo-W alloy;

When the diffusion layer 2 is a porous material, the porous material is porous stainless steel or porous titanium-aluminum alloy.

In this embodiment, the thickness of the dissociation layer 1 is 5-500 nm, further 5-500 nm, and further 100 nm; the thickness of the recombination layer 3 is 5-500 nm, further 10-300 nm, and further The thickness of the diffusion layer 2 is 20-20000 μm, 50-15000 μm, 50-15 μm, and 50-100 μm further.

In the performance test of the produced composite membrane, the hydrogen transmission rate of the composite membrane is ≥1×10 ^{- 3} molm ^-2 s ^-1 , specifically (4-6)×10 ^-2 molm ^-2 s ^{- 1.} The operating temperature of the composite membrane is 300-550°C, specifically 450-550°C, in addition, the hydrogen permeation flow rate of the composite membrane is ≥1×10 ^-8 molH ₂ m ^-1 s ^-1 Pa ^-0.5 , specifically (2 -5)×10 ^-8 molH ₂ m _-1 s _{- 1} Pa _-0.5 , with good performance.

Embodiment 2

A preparation method of a zirconium carbide membrane for hydrogen separation, according to the following steps:

Step 1: Pre-treat the diffusion layer 2; use an ultrasonic cleaner to clean the cut V-foil. During cleaning, use acetone, anhydrous ethanol, and deionized water to ultrasonically clean the V-foil for 10 minutes in sequence, and then perform drying treatment. .

Step 2: The surface of the diffusion layer 2 is cleaned with an ion beam; the pretreated V foil and the zirconium carbide (atomic ratio 1:1) target are respectively placed on the sample stage and the target head of the magnetron sputtering coating chamber, Use a molecular pump to pump the vacuum of the chamber to below 10 ^-4 Pa, set the electron beam current to 50mA, the argon flow rate to 5sccm, the chamber pressure to 3-8*10 ^-2 Pa, and use the argon ion beam to clean the surface of the V foil for 30min .

Step 3: Use one of magnetron sputtering, ion beam sputtering, electron beam evaporation, pulse deposition, molecular beam epitaxy and atomic layer deposition to form a dissociation layer 1 on one side of the diffusion layer 2; set the position of the V foil The negative bias voltage of the coating chamber is 0V, the sputtering power is 300W, the chamber pressure is 1.0Pa, and the substrate temperature is 25℃. Lower the baffle, start timing 20min for formal sputtering, and deposit a layer of zirconium carbide film on the surface of the V foil.

Step 4: Turn the V foil over, repeat Step 3, coat the other side of the V foil with a layer of zirconium carbide film, and take it out to obtain a zirconium film.

When the prepared zirconium film is purified by hydrogen, the working principle is shown in Figure 2: hydrogen can pass through the dissociation layer 1, the diffusion layer 2 and the recombination layer 3 in sequence, while other impurities such as CO ₂ and CO cannot pass through, so that the Hydrogen is separated and purified.

Figure 3 shows the SEM cross-sectional view of the prepared zirconium thin film, and the thickness of the zirconium thin film is 200 nm.

Figure 4 shows the GIXRD pattern of the zirconium thin film prepared by magnetron sputtering. The results show that the zirconium thin film with a zirconium-carbon ratio of 1:1 prepared by magnetron sputtering has better crystallinity.

Using the hydrogen permeation device to set different pressures at both ends of the hydrogen separation and purification membrane of this embodiment, the obtained change curve of the hydrogen flux with the upstream pressure is shown in Figure 5; The hydrogen permeation flow rate expressed by the permeation hydrogen molar amount of the membrane per unit time and unit area, in molH ₂ m ^-2 s ^-1 , where P _u represents the upper end pressure of the composite membrane. The results in Fig. 5 show that when the hydrogen permeation temperature is constant, the hydrogen permeation flux J increases with the increase of the upstream pressure P _u ; when the P _u is the same, the J increases with the increase of the temperature. The hydrogen permeation flux J reached 0.12molH ₂ m ^-2 s ^-1 at 650℃ and 800KPa.

The variation curve of the hydrogen permeation flux of the hydrogen separation composite membrane in this example with working time is shown in Figure 8. After hydrogen permeation for up to 40 hours, the hydrogen permeation flux remained stable, and the high temperature thermal stability of the zirconium film was good.

Embodiment 3

Referring to the preparation method of the second embodiment, the remaining steps and parameters are the same as those of the second embodiment except that the sputtering power is increased to 200W during the coating process in the third and fourth steps.

The change curve of the hydrogen permeation flux of the zirconium thin film in this embodiment with the upstream pressure is shown in FIG. 6 . The results in Fig. 6 show that when the hydrogen permeation temperature is constant, the hydrogen permeation flux J increases with the increase of the upstream pressure P _u ; when the P _u is the same, the J increases with the increase of the temperature. The hydrogen permeation flux J reached 0.09molH ₂ m ^-2 s ^-1 at 650℃ and 800KPa.

Embodiment 4

Referring to the preparation method of the second embodiment, the remaining steps and parameters are the same as those of the second embodiment except that the sputtering power is increased to 100W during the coating process in the third and fourth steps.

The change curve of the hydrogen permeation flux of the zirconium thin film in this embodiment with the upstream pressure is shown in FIG. 7 . The results in Fig. 7 show that when the hydrogen permeation temperature is constant, the hydrogen permeation flux J increases with the increase of the upstream pressure P _u ; when the P _u is the same, the J increases with the increase of the temperature. The hydrogen permeation flux J reached 0.06molH ₂ m ^-2 s ^-1 at 650℃ and 800KPa.

Compared with the prior art, the present invention has the following advantages:

1. The present invention combines the novel zirconium carbide hydrogen separation membrane with the diffusion layer material to replace the precious metal Pd, which greatly reduces the application cost of hydrogen separation;

2. As a new type of hydrogen separation membrane, zirconium carbide has good stability and hydrogen permeability in high temperature environment;

3. The zirconium carbide and substrate composite membrane of the present invention has better high-temperature hydrogen permeation stability than pure Pd, Pd alloy and Pd/diffusion layer composite membrane;

The novel niobium carbide hydrogen separation membrane of the present invention provides a new choice for materials and devices for realizing novel, cheap, efficient and stable hydrogen separation and purification.

This specific embodiment is only an explanation of the present invention, and it does not limit the present invention. Those skilled in the art can make modifications without creative contribution to the present embodiment as needed after reading this specification, but as long as the rights of the present invention are used All claims are protected by patent law.

Claims (10)

1. A zirconium carbide membrane for hydrogen separation, characterized by: include from last to stacking gradually down be used for to hydrogen carry out dissociation layer (1), be used for to hydrogen atom diffusion layer (2) and be used for carrying out recombination layer (3) of recombining to hydrogen atom, dissociation layer (1) with recombination layer (3) are the zirconium carbide film.

2. The zirconium carbide film for hydrogen separation according to claim 1, wherein the molar ratio of Zr to C in the zirconium carbide thin film is (1-6): (1-3).

3. The zirconium carbide film for hydrogen separation according to claim 2, wherein the molar ratio of Zr to C in the zirconium carbide thin film is (1-3): 1.

4. the zirconium carbide membrane for hydrogen separation according to claim 1, wherein the diffusion layer (2) is made of a dense material or a porous material;

when the diffusion layer (2) is a compact material, the compact material is one of V, Nb, Ta, Mo, Ni, Ti, Pd, Pt, V-Ni alloy, V-Cr alloy, V-Cu alloy, V-Fe alloy, V-Al alloy, V-Co alloy, V-Mo alloy, V-W alloy, V-Ti-Ni alloy, V-Fe-Al alloy, V-Mo-W alloy, Nb-Ti-Ni alloy, Nb-Ti-Co alloy and Nb-Mo-W alloy;

when the diffusion layer (2) is a porous material, the porous material is porous stainless steel or porous titanium-aluminum alloy.

5. Zirconium carbide film for hydrogen separation according to claim 1, characterized in that the thickness of the dissociation layer (1) is 5-500nm, the thickness of the recombination layer (3) is 5-500nm and the thickness of the diffusion layer (2) is 20-20000 μm.

6. A method of producing a zirconium carbide film for hydrogen separation according to any one of claims 1 to 5, wherein the following steps are carried out:

the method comprises the following steps: pretreating the diffusion layer (2);

step two: cleaning the surface of the diffusion layer (2) by using ion beams;

step three: forming a dissociation layer (1) on one surface of the diffusion layer (2) by adopting one of magnetron sputtering, ion beam sputtering, electron beam evaporation, pulse deposition, molecular beam epitaxy and atomic layer deposition;

step four: and forming a recombination layer (3) on the other surface of the diffusion layer (2) by adopting one of magnetron sputtering, ion beam sputtering, electron beam evaporation, pulse deposition, molecular beam epitaxy and atomic layer deposition.

7. The method according to claim 6, wherein the step of forming the zirconium carbide film for hydrogen separation comprises forming the zirconium carbide film,

in the first step, the diffusion layer (2) is ultrasonically cleaned for 5-15min by sequentially adopting acetone and absolute ethyl alcohol, the ultrasonic cleaning is repeated for 2-3 times, then deionized water is used for washing for 1-2 min, and then drying is carried out.

8. The method for preparing a zirconium carbide film for hydrogen separation according to claim 6, wherein in step three, the dissociation layer (1) is formed on one side of the diffusion layer (2) by magnetron sputtering; in the fourth step, magnetron sputtering is adopted to form the recombination layer (3) on the other side of the diffusion layer (2).

9. The method of claim 8, wherein the step of forming the zirconium carbide film for hydrogen separation comprises forming the zirconium carbide film,

the cleaning conditions in the second step include: the vacuum degree in the sputtering cavity is less than 10^-4Pa; the temperature of the diffusion layer is 25-600 ℃; the negative bias voltage of the diffusion layer is 0-500V; introducing argon gas flow of 3-10 sccm; setting electron beam current of 50mA, argon gas flow rate of 5sccm and chamber pressure of 3-8 x 10^-2Pa, continuously bombarding for 5-60 min;

the magnetron sputtering conditions in the third step and the fourth step comprise: magnetron sputtering vacuum degree less than 10^-4Pa, the temperature of the diffusion layer is 25-600 ℃, the negative bias of the diffusion layer is 0-500V, the flow of introduced argon is 10-50sccm, the working pressure is 0.2-2Pa, the working power is 50-400W, and the sputtering time is 2-120 min.

10. Use of a zirconium carbide membrane according to any one of claims 1 to 9 for hydrogen separation in hydrogen separation and/or hydrogen purification.

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