A hybrid proton-electron conductor hydrogen-permeable membrane material and a preparation method and application thereof

Abstract

The application discloses a kind of mixed proton-electron conductor hydrogen permeation membrane materials and its preparation method and application.The chemical general formula of the mixed proton-electron conductor hydrogen permeation membrane material of the application is ACe a Fe b P x O 3‑δ In the formula, A is one or two of Ba, Sr and Ca, a+b+x=1, 0.9≤a+b<1, 0

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydrogen separation and purification, and particularly relates to a mixed proton-electron conductor hydrogen permeation membrane material and a preparation method and application thereof. BACKGROUND

[0002] Hydrogen is an ideal clean energy carrier and a key chemical raw material, and is widely used in the fields of transportation and chemical industry (for example: aerospace, metal smelting, synthetic ammonia, etc.). Hydrogen on an industrial scale is mainly produced by a methane steam reforming process, and the produced hydrogen is accompanied by other components, which needs to be separated and purified subsequently. Membrane separation technology has the advantages of high efficiency, simple operation, energy saving, etc., and is considered to be an effective technology for purifying hydrogen. The mixed proton-electron conductor hydrogen permeation membrane has 100% hydrogen selectivity, and has great application potential in hydrogen separation and purification and related membrane reactors.

[0003] Perovskite oxides (chemical formula: ABO3) are the most widely studied mixed proton-electron conductor hydrogen permeation membrane materials, and have high proton conductivity, but poor electronic conductivity, that is, the hydrogen permeation flux is very low even at high temperature, for example: Cai et al. developed a mixed proton-electron conductor hydrogen permeation membrane material BaCe 0.95 Nd 0.05 O 3-δ , which has very low electronic conductivity, resulting in a very low hydrogen permeation flux (only 0.017 mL·min -1 ·cm -2 ).

[0004] At present, in order to improve the electronic conductivity of the mixed proton-electron conductor hydrogen permeation membrane material and further improve the hydrogen permeation performance thereof, researchers mainly use the following methods: doping multivalent metal ions, adjusting the A / B site stoichiometric ratio, introducing a second electronic conductor to construct a two-phase membrane, etc., for example: Zhuang et al. developed a metal-ceramic two-phase membrane material Ni-BaCe 0.85 Fe 0.15 O 3-δ , which has a hydrogen permeation flux of 0.325 mL·min -1 ·cm -2 at 1000℃; Cheng et al. developed a BaCe 0.5 Fe 0.5 O 3-δ two-phase hydrogen permeation membrane, which can automatically decompose into a BaCe 0.85 Fe 0.15 O 3-δ main proton conductive phase and a BaCe 0.15 Fe 0.85 O 3-δThe two thermodynamically stable phases of the main electronic conductive phase can exhibit a high hydrogen permeation flux. However, the two-phase hydrogen permeable membrane materials described above can exhibit a high hydrogen permeation flux, but due to the difference between the two phases in the material and the mismatch in thermal compatibility, the two phases will react at high temperatures to produce a third impurity phase, affecting the thermal stability and chemical stability of the material, limiting the practical application of the two-phase hydrogen permeable membrane materials.

[0005] Therefore, it is of great significance to develop a mixed proton-electron conductor hydrogen permeable membrane material with excellent hydrogen permeation performance, good thermal stability and chemical stability. SUMMARY

[0006] The purpose of the present application is to provide a mixed proton-electron conductor hydrogen permeable membrane material and its preparation method and application.

[0007] The technical solution adopted by the present application is:

[0008] A mixed proton-electron conductor hydrogen permeable membrane material, whose chemical formula is ACe a Fe b P x O 3-δ (ACeO 3-δ is the main proton conductive phase, and AFeO 3-δ is the main electronic conductive phase), wherein A is one or two of Ba, Sr and Ca, a+b+x=1, 0.9≤a+b<1, 0

[0009] Preferably, a mixed proton-electron conductor hydrogen permeable membrane material, whose chemical formula is ACe 0.5 Fe 0.45 P 0.05 O 3-δ , wherein A is one or two of Ba, Sr and Ca, and δ is a non-stoichiometric ratio, 0≤δ≤1.

[0010] A preparation method of the mixed proton-electron conductor hydrogen permeable membrane material as described above comprises the following steps:

[0011] 1) Mix the oxide of A or / and the carbonate of A, cerium oxide (CeO2), iron oxide (Fe2O3) and ammonium dihydrogen phosphate (NH4H2PO4) for wet ball milling, and then dry, calcine and grind to obtain phase-forming powder;

[0012] 2) Inject the phase-forming powder into a mold for compression molding to obtain a membrane green body;

[0013] 3) Sinter the membrane green body to obtain the mixed proton-electron conductor hydrogen permeable membrane material.

[0014] Preferably, the wet ball milling in step 1) adopts a grinding aid solvent of at least one of ethanol and acetone.

[0015] Preferably, the amount of the grinding aid solvent is 100% to 150% of the total mass of the oxide of A and / or the carbonate of A, cerium oxide, iron oxide and ammonium dihydrogen phosphate.

[0016] Preferably, the time of the wet ball milling in step 1) is 24h to 48h.

[0017] Preferably, the drying mode in step 1) is natural ventilation drying.

[0018] Preferably, the specific operation of the calcination in step 1) is: increasing the temperature from room temperature to 900℃ to 1200℃ at a temperature increasing rate of 1℃ / min to 5℃ / min, and then keeping the temperature for 5h to 10h.

[0019] Preferably, the mold in step 2) is a stainless steel mold.

[0020] Preferably, the press forming in step 2) is performed under a pressure of 10MPa to 25MPa, and the pressure keeping time is 8min to 15min.

[0021] Preferably, the specific operation of the sintering in step 3) is: increasing the temperature from room temperature to 1300℃ to 1500℃ at a temperature increasing rate of 1℃ / min to 2℃ / min, and then keeping the temperature for 10h to 20h.

[0022] The application of the mixed proton-electron conductor hydrogen permeable membrane material as described above to selectively separate hydrogen from a hydrogen-containing mixed gas.

[0023] A membrane reactor comprising the mixed proton-electron conductor hydrogen permeable membrane material.

[0024] The mixed proton-electron conductor hydrogen permeable membrane material has excellent hydrogen permeability, good thermal stability and chemical stability, and the preparation method is simple and suitable for large-scale industrial application.

[0025] Specifically:

[0026] The application adjusts the ratio of the proton conductive phase and the electron conductive phase in the mixed proton-electron conductor hydrogen permeable membrane material by doping non-metal ions (P ions), reduces the sintering temperature of the membrane blank, stabilizes the two-phase structure, reduces the precipitation of impurities, ensures that the prepared mixed proton-electron conductor hydrogen permeable membrane material has excellent hydrogen permeability, greatly improves the thermal stability and chemical stability of the mixed proton-electron conductor hydrogen permeable membrane material (still has good stability in the atmosphere containing water vapor), and is suitable for large-scale industrial application. Attached Figure Description

[0027] Figure 1 The images show the XRD patterns of the phase-forming powders in Examples 1-3 and the comparative examples.

[0028] Figure 2 The images show SEM images of the surface and cross-section of the hydrogen permeable membrane material of the hybrid proton-electron conductor in Example 1.

[0029] Figure 3 The images show SEM images of the surface and cross-section of the hydrogen permeable membrane material used in the comparative example, which is a hybrid proton-electron conductor.

[0030] Figure 4 The hydrogen permeation rate-time curves are for the mixed proton-electron conductor hydrogen permeable membrane materials in Examples 1-3 and the comparative examples.

[0031] Figure 5 XRD pattern of the hydrogen permeation membrane material of the mixed proton-electron conductor after hydrogen permeation test was completed. Detailed Implementation

[0032] The present invention will be further explained and described below with reference to specific embodiments.

[0033] Example 1:

[0034] A hybrid proton-electron conductor hydrogen-permeable membrane material, the preparation method of which includes the following steps:

[0035] 1) Mix 13.992g of BaCO3, 6.102g of CeO2, 2.548g of Fe2O3 and 0.4078g of NH4H2PO4, add 25mL of ethanol, and then wet ball mill at 340r / min for 24h. Then dry naturally in ventilation. Then put the dried powder into a muffle furnace and heat it from room temperature to 1000℃ at a heating rate of 2℃ / min. Then hold it at that temperature for 10h, and then cool it to room temperature at a cooling rate of 2℃ / min. Then grind it to obtain the phase-forming powder.

[0036] 2) Inject 1.5g of phase-forming powder into a cylindrical stainless steel mold with an inner diameter of 16mm, and then keep it under a pressure of 25MPa for 8min to obtain a film preform.

[0037] 3) Place the membrane preform in a muffle furnace and heat it from room temperature to 1300℃ at a heating rate of 1.5℃ / min, hold it at that temperature for 10 hours, and then cool it back to room temperature at a cooling rate of 1.5℃ / min to obtain the hybrid proton-electron conductor hydrogen permeable membrane material (chemical formula BaCe). 0.5 Fe 0.45 P 0.05 O 3-δIn the formula, δ is a non-stoichiometric ratio, 0≤δ≤1).

[0038] Comparative example:

[0039] A hybrid proton-electron conductor hydrogen-permeable membrane material, the preparation method of which includes the following steps:

[0040] 1) Mix 13.931g of BaCO3, 6.075g of CeO2 and 2.818g of Fe2O3 and add 25mL of ethanol. Then, wet ball mill the mixture for 24h at a ball mill speed of 340r / min. After natural ventilation drying, place the dried powder into a muffle furnace and heat it from room temperature to 1000℃ at a heating rate of 2℃ / min. Hold the temperature for 10h and then cool it to room temperature at a cooling rate of 2℃ / min. Then grind the powder to obtain the phase-forming powder.

[0041] 2) Inject 1.5g of phase-forming powder into a cylindrical stainless steel mold with an inner diameter of 16mm, and then keep it under a pressure of 25MPa for 8min to obtain a film preform.

[0042] 3) Place the membrane preform in a muffle furnace and heat it from room temperature to 1350℃ at a heating rate of 1.5℃ / min, hold it at that temperature for 10 hours, and then cool it back to room temperature at a cooling rate of 1.5℃ / min to obtain the hybrid proton-electron conductor hydrogen permeable membrane material (chemical formula BaCe). 0.5 Fe 0.5 O 3-δ In the formula, δ is a non-stoichiometric ratio, 0≤δ≤1).

[0043] Performance testing:

[0044] 1) X-ray diffraction (XRD) patterns of the phase-forming powders in Example 1 and the comparative example are shown below. Figure 1 (a is the XRD pattern, and b is the two-phase scale diagram obtained from theoretical calculation and refined calculation) as shown.

[0045] Depend on Figure 1 It can be seen that the phase-forming powder in the comparative example (without phosphorus doping) has a perovskite structure, and it can be clearly seen that it is composed of two phases without any other impurities. The phase-forming powder in Example 1 (doped with phosphorus) still maintains the perovskite structure, and it can also be clearly seen that it is composed of two phases without any impurities.

[0046] 2) Scanning electron microscopy (SEM) images of the surface and cross-section of the hybrid proton-electron conductor hydrogen permeable membrane material in Example 1 and the comparative example are shown below. Figure 2 (a is the surface, b is the cross-section, and c is a magnified view of the cross-section) and Figure 3 (a is the surface, b is the cross-section, and c is a magnified view of the cross-section).

[0047] Depend on Figure 2 It can be seen that the grains on the surface of the hybrid proton-electron conductor hydrogen permeable membrane material in Example 1 are complete and tightly connected, the grain boundaries are obvious and clearly distinguishable, and the three grain boundary angles are close to 120°, indicating that the grains are well developed. Its cross-sectional view also shows that there are no obvious pore structures and pore defects inside the membrane. The grains are tightly connected, and the gas cannot directly pass through the inner lattice of the membrane, indicating that the hybrid proton-electron conductor hydrogen permeable membrane material obtained by sintering at 1300℃ has a dense structure.

[0048] Depend on Figure 3 It can be seen that the grains on the surface of the hydrogen permeable membrane material of the mixed proton-electron conductor in the comparative example are complete and tightly connected, and the grain boundaries are obvious and clearly distinguishable. Its cross-sectional view also shows that there are no obvious pore structures and pore defects inside the membrane. The grains are tightly connected, and the gas cannot directly pass through the inner lattice of the membrane, indicating that the hydrogen permeable membrane material of the mixed proton-electron conductor obtained by sintering at 1350℃ has a dense structure.

[0049] 3) The mixed proton-electron conductor hydrogen permeable membrane material from Example 1 and the comparative example was first coarsely ground with 400-mesh SiC sandpaper to a thickness of approximately 0.8 mm, then further ground with 800-mesh sandpaper to a thickness of approximately 0.5 mm, and then polished with 2000-mesh sandpaper. After ultrasonic cleaning, it was sealed to one end of a φ16 corundum tube with high-temperature ceramic adhesive. A φ30 quartz glass tube was then placed outside the corundum tube for feeding. After standing for 24 hours to allow the high-temperature ceramic adhesive to dry completely, the resulting device was fixed in a tubular high-temperature furnace. The airtightness of the device was tested using the pressure test. If the device was leak-free, heating could begin. The heating procedure was as follows: First... The temperature was increased from room temperature to 80°C at a rate of 1°C / min and held for 2 hours. Then, the temperature was increased to 150°C at a rate of 1°C / min and held for 2 hours. Next, the temperature was increased to 650°C at a rate of 1°C / min and held for 2 hours. Finally, the temperature was increased to 950°C at a rate of 1°C / min and held for testing. The flow rate of the gases used in the test was precisely controlled by a mass flow controller. A hydrogen-helium mixture with a volume ratio of 1:1 was introduced into the feed side at a flow rate of 100 mL / min. Argon gas at a flow rate of 100 mL / min was used as the purge gas. The purge exhaust gas was introduced into an Agilent 7890A gas chromatograph for hydrogen concentration determination. The flow rate of the exhaust gas was measured using a soap bubble flow meter. The hydrogen permeation rate-time curves of the mixed proton-electron conductor hydrogen permeable membrane materials in Example 1 and the comparative example are shown below. Figure 4 As shown, the hydrogen permeability membrane material of the mixed proton-electron conductor, after completing the hydrogen permeability test, was ground into powder and its phase structure was tested. The obtained XRD pattern is shown in the figure. Figure 5 As shown.

[0050] Depend on Figure 4It can be seen that the hydrogen permeation amount of the mixed proton-electron conductor hydrogen permeation membrane material in Example 1 is very stable, and the hydrogen permeation stability is good under the same test conditions, while the hydrogen permeation amount of the mixed proton-electron conductor hydrogen permeation membrane material in the comparative example decays very obviously, and the hydrogen permeation stability is poor, indicating that the mixed proton-electron conductor hydrogen permeation membrane material doped with phosphorus element has excellent hydrogen permeation stability.

[0051] It can be seen that the phase structure of the mixed proton-electron conductor hydrogen permeation membrane material in Example 1 is basically unchanged before and after the hydrogen permeation amount test, and no other impurity phase is generated, indicating that it has good chemical stability; the phase structure of the mixed proton-electron conductor hydrogen permeation membrane material in the comparative example changes before and after the hydrogen permeation amount test, and Fe2O3 impurity phase is generated, indicating that its chemical stability is poor. Figure 1 Figure 5 It can be seen that the phase structure of the mixed proton-electron conductor hydrogen permeation membrane material in Example 1 is basically unchanged before and after the hydrogen permeation amount test, and no other impurity phase is generated, indicating that it has good chemical stability; the phase structure of the mixed proton-electron conductor hydrogen permeation membrane material in the comparative example changes before and after the hydrogen permeation amount test, and Fe2O3 impurity phase is generated, indicating that its chemical stability is poor.

[0052] Example 2:

[0053] A kind of mixed proton-electron conductor hydrogen permeation membrane material, its preparation method includes the following steps:

[0054] 1) 13.961 g of BaCO3, 6.089 g of CeO2 and 2.683 g of Fe2O3 and 0.2034 g of NH4H2PO4 are mixed, then 25 mL of ethanol is added, then wet ball milling is carried out in a ball mill at a speed of 340 r / min for 24 h, then it is naturally ventilated and dried, then the dried powder is placed in a muffle furnace, heated from room temperature to 1000 ℃ at a rate of 2 ℃ / min, then kept for 10 h, then cooled to room temperature at a rate of 2 ℃ / min, then ground to obtain a phase forming powder;

[0055] 2) 1.5 g of the phase forming powder is injected into a cylindrical stainless steel mold with an inner diameter of 16 mm, then kept at a pressure of 25 MPa for 8 min to obtain a membrane green body;

[0056] 3) the membrane green body is placed in a muffle furnace, heated from room temperature to 1275 ℃ at a rate of 1.5 ℃ / min, then kept for 10 h, then cooled to room temperature at a rate of 1.5 ℃ / min to obtain a mixed proton-electron conductor hydrogen permeation membrane material (chemical formula is BaCe 0.5 Fe 0.475 P 0.025 O 3-δ , wherein δ is a non-stoichiometric ratio, 0≤δ≤1).

[0057] Performance test:

[0058] 1) The XRD pattern of the phase forming powder in Example 2 is shown in Figure 1 (a is the XRD pattern, b is the two-phase ratio pattern obtained by theoretical calculation and refinement calculation).​

[0059] It can be seen from Figure 1 that the phase-forming powder (doped with phosphorus) in Example 2 maintains the perovskite structure, and it can also be clearly seen that it is composed of two phases, and no impurity phase is generated.

[0060] 2) The hydrogen permeation amount-time relationship curve of the mixed proton-electron conductor hydrogen permeation membrane material in Example 2 (the test method is the same as that in Example 1) is shown in Figure 4 .

[0061] It can be seen from Figure 4 that under the same test conditions, the hydrogen permeation stability of the mixed proton-electron conductor hydrogen permeation membrane material in Example 2 is better than that of the mixed proton-electron conductor hydrogen permeation membrane material in the comparative example.

[0062] Example 3:

[0063] A mixed proton-electron conductor hydrogen permeation membrane material, the preparation method thereof comprises the following steps:

[0064] 1) 14.054 g of BaCO3, 6.129 g of CeO2, 2.275 g of Fe2O3 and 0.8192 g of NH4H2PO4 are mixed, then 25 mL of ethanol is added, and then 24 h of wet ball milling is performed under the condition that the rotation speed of the ball mill is 340 r / min, and then natural ventilation drying is performed, and then the dried powder is placed into a muffle furnace, and then the temperature is raised from room temperature to 1000℃ at a temperature raising rate of 2℃ / min, and then the temperature is kept for 10 h, and then the temperature is lowered to room temperature at a temperature lowering rate of 2℃ / min, and then grinding is performed, so as to obtain a phase-forming powder;

[0065] 2) 1.5 g of the phase-forming powder is injected into a cylindrical stainless steel mold with an inner diameter of 16 mm, and then the temperature is kept for 8 min under the condition that the pressure is 25 MPa, so as to obtain a membrane green body;

[0066] 3) The membrane green body is placed into a muffle furnace, and then the temperature is raised from room temperature to 1275℃ at a temperature raising rate of 1.5℃ / min, and then the temperature is kept for 10 h, and then the temperature is lowered to room temperature at a temperature lowering rate of 1.5℃ / min, so as to obtain a mixed proton-electron conductor hydrogen permeation membrane material (the chemical general formula is BaCe 0.5 Fe 0.4 P 0.1 O 3-δ , in the formula, δ is a non-stoichiometric ratio, and 0≤δ≤1).

[0067] Performance test:

[0068] 1) The XRD pattern of the phase-forming powder in Example 3 is shown in Figure 1 (a is the XRD pattern, and b is the two-phase proportion pattern obtained by theoretical calculation and refinement calculation).

[0069] Depend on Figure 1 It can be seen that the phase-forming powder (doped with phosphorus) in Example 3 maintains the perovskite structure, and it can also be clearly seen that it is composed of two phases without generating any impurity phases.

[0070] 2) The hydrogen permeation rate-time curve of the hybrid proton-electron conductor hydrogen permeable membrane material in Example 3 (test method is the same as in Example 1) is shown below. Figure 4 As shown.

[0071] Depend on Figure 4 It can be seen that, under the same test conditions, the hydrogen permeation stability of the hybrid proton-electron conductor hydrogen permeation membrane material in Example 3 is better than that of the hybrid proton-electron conductor hydrogen permeation membrane material in the comparative example.

[0072] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A mixed proton-electron conductor hydrogen-permeable membrane material, characterized by, Chemical formula: ACe a Fe b P x O 3-δ , wherein A is one or two of Ba, Sr, and Ca, a+b+x=1, 0.9≤a+b<1, 0 2. A method of producing a mixed proton-electron conductor hydrogen- permeable membrane material as claimed in claim 1, characterized in that The method comprises the following steps: 1) mixing oxide of A and / or carbonate of A, cerium oxide, iron oxide and ammonium dihydrogen phosphate, wet ball milling, drying, calcining and grinding to obtain phase-forming powder; 2) injecting the phase-forming powder into a mold for compression molding to obtain a green membrane; 3) sintering the green membrane to obtain the mixed proton-electron conductor hydrogen permeable membrane material.

3. The method of claim 2, wherein: The wet ball milling in step 1) uses at least one of ethanol and acetone as a grinding solvent.

4. The production method according to claim 2 or 3, characterized by: The wet ball milling in step 1) is performed for 24-48 hours.

5. The production method according to claim 2 or 3, characterized by: The drying in step 1) is performed by natural ventilation drying.

6. The method of claim 2 or 3, wherein: The calcining in step 1) is performed at a temperature increasing rate of 1-5 ℃ / min from room temperature to 900-1200 ℃, and then kept for 5-10 hours.

7. The method of claim 2, wherein: The compression molding in step 2) is performed at a pressure of 10-25 MPa, and the pressure keeping time is 8-15 minutes.

8. The method of any one of claims 2, 3, and 7, wherein: The sintering in step 3) is performed at a temperature increasing rate of 1-2 ℃ / min from room temperature to 1300-1500 ℃, and then kept for 10-20 hours.

9. Use of the mixed proton-electron conductor hydrogen permeable membrane material according to claim 1 for selectively separating hydrogen from a hydrogen-containing mixed gas.

10. A membrane reactor characterized by, A hydrogen permeable membrane material comprising the mixed proton-electron conductor hydrogen permeable membrane material according to claim 1.

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