High-flux MIEC1-MIEC2 double-phase oxygen permeation membrane material and preparation method thereof

Abstract

The invention discloses a high-flux MIEC1-MIEC2 biphase oxygen permeation membrane material and a preparation method thereof. The preparation method comprises the following steps: S1, respectively preparing modified SDC powder and Sm < 0.5 > Sr < 0.5 > Cu < 0.2 > Fe < 0.8 > O < 3-delta > powder by adopting a sol-gel method; s2, mixing the modified SDC powder with the Sm < 0.5 > Sr < 0.5 > Cu < 0.2 > Fe < 0.8 > O < 3-delta > powder, grinding and drying to obtain dual-phase membrane powder; s3, high-temperature granulation is conducted on the biphase membrane powder, and the high-flux MIEC1-MIEC2 biphase oxygen permeation membrane material is obtained.The high-flux MIEC1-MIEC2 biphase oxygen permeation membrane material has the advantages that the high stability of the biphase oxygen permeation membrane is guaranteed, meanwhile, the oxygen permeation performance of the biphase oxygen permeation membrane is improved to a certain degree, and the bottleneck problem of balance between the oxygen permeation rate and the stability of the oxygen permeation membrane is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of mixed conductor oxygen permeable membranes, and in particular relates to a high-flux MIEC1-MIEC2 two-phase oxygen permeable membrane material and a preparation method thereof. Background Art

[0002] Due to the widespread demand for pure oxygen in the energy field, air separation oxygen production technology has become particularly important. Traditional oxygen production processes mainly include cryogenic separation, pressure swing adsorption and polymer membrane separation. However, the three technologies are mutually restricted by factors such as oxygen purity, cost and oxygen production efficiency. Inorganic dense ceramic oxygen permeable membranes with mixed conduction of oxygen ions and electrons can obtain 99.99% high-purity oxygen, and the theoretical selective permeability reaches 100%. Therefore, it has become a research hotspot in recent years. In particular, for the application of membrane reactors, the integration of separation process and subsequent reactions is realized, making the oxygen permeable membrane extremely competitive. However, the oxygen permeable membrane has to achieve industrial requirements for high-throughput and stable operation in harsh atmospheres such as CO2 (1 mL·min -1 cm -2 ), still requires a lot of basic research. The dual-phase oxygen permeable membrane composed of fluorite materials with oxygen ion conduction (IC) and perovskite materials with mixed ion electron conduction capacity (MIEC) shows excellent stability in harsh environments and is a very promising type of membrane material for industrial applications. However, dual-phase membranes generally have limitations in oxygen ion conduction, and their oxygen permeability needs to be further improved.

[0003] Fluorite phase is the main conductor of oxygen ion conduction, and improving its conductivity behavior will help improve the performance of the biphasic membrane. 0.8 Sm 0.2 O 2-δ (SDC) fluorite structural materials are widely used in oxygen ion conducting phases of oxygen permeable membranes and solid oxide fuel cells (SOFC) electrolytes due to their good oxygen ion conductivity and chemical stability. However, the SDC density sintering temperature is too high (1400 ℃ ~ 1600 ℃). The addition of appropriate sintering aids can not only reduce the high sintering temperature of fluorite materials, but more importantly, it may be accompanied by improvements in conductivity behavior. For example, in Ce 0.8 Gd0 .2 O 2-δ When a sintering aid is added to the (GDC) fluorite material, the conductivity behavior is improved and a certain amount of electronic conductivity is introduced. The electronic conductivity introduced in the process makes it easy to cause battery failure when used as a SOFC electrolyte. However, when used as a single-phase fluorite-type oxygen permeable membrane material, it promotes oxygen permeability. However, due to the electronic conduction limitation of the single-phase fluorite-type oxygen permeable membrane, its oxygen permeability is still at a low level. Invention content In view of this, the present invention aims to provide a high-throughput MIEC1-MIEC2 biphasic oxygen permeable membrane material and its preparation method to solve at least one technical problem in the background art.

[0005] To achieve the above object, the technical solution of the present invention is realized as follows: To solve the trade-off problem between stability and high oxygen permeability in the design of the above oxygen permeable membrane, the present invention provides a very promising design concept, which composes a biphasic membrane of a fluorite phase with a sintering aid added and a mixed conducting perovskite phase. This can not only break the limitation of electronic conduction in the single-phase fluorite-type oxygen permeable membrane but also weaken the limitation of oxygen ion conduction on the biphasic membrane. At the same time, there are still two theoretical advantages: on the one hand, the improvement of the conductivity behavior and the enhancement of the mixed conduction ability due to the introduction of electronic conduction change the fluorite phase from an oxygen ion conductor to a mixed conductor, thus expanding the active sites for the oxygen surface exchange reaction (OSER) to the entire surface of the membrane material. On the other hand, the blocking effect of electronic conduction in the fluorite phase will also be weakened.

[0006] A high-throughput MIEC1-MIEC2 biphasic oxygen permeable membrane material includes Sm with mixed ion-electron conduction ability 0.5 Sr 0.5 Cu 0.2 Fe 0.8 O 3-δ and a fluorite phase SDC modified by a sintering element.

[0007] Furthermore, the sintering element includes one or more of Cu, Co, or Fe; Preferably, the sintering aid includes one or more of cerium nitrate hexahydrate, samarium nitrate hexahydrate, copper nitrate, cobalt nitrate hexahydrate, or iron nitrate nonahydrate.

[0008] Furthermore, the content of the sintering element in a high-throughput MIEC1-MIEC2 biphasic oxygen permeable membrane material is at least 5%.

[0009] Furthermore, the content of SDC in a high-throughput MIEC1-MIEC2 biphasic oxygen permeable membrane material is 50% - 70%.

[0010] The preparation method of the above high-throughput MIEC1-MIEC2 biphasic oxygen permeable membrane material includes the following steps: S1: Respectively prepare modified SDC powder and Sm 0.5 Sr 0.5 Cu 0.2 Fe 0.8 O 3-δ powder by the sol-gel method; S2: Mix the modified SDC powder and Sm 0.5 Sr 0.5Cu 0.2 Fe 0.8 O 3-δ The powder of the two-phase membrane is obtained by mixing, grinding and drying the powders. S3: High-temperature granulation is carried out on the powder of the two-phase membrane to obtain a high-flux MIEC1-MIEC2 two-phase oxygen permeable membrane material.

[0011] Furthermore, the preparation of the modified SDC powder in step S1 includes the following steps: The modified SDC powder or Sm in step S1 0.5 Sr 0.5 Cu 0.2 Fe 0.8 O 3-δ The preparation of the powder includes the following steps: The nitrates of the sintering aid elements and other element salts are placed in deionized water, heated and stirred. After complete dissolution, ethylenediaminetetraacetic acid and citric acid monohydrate are added, and the pH value is adjusted. After continuous heating and stirring, it is dried in an oven and kept warm in a muffle furnace to obtain the modified SDC powder.

[0012] Furthermore, the nitrates of the sintering aid elements of the modified SDC powder include copper nitrate, cobalt nitrate hexahydrate and iron nitrate nonahydrate; Preferably, the other element salts of the modified SDC powder are cerium salts and samarium salts; Preferably, the cerium salt is cerium nitrate hexahydrate and the samarium salt is samarium nitrate hexahydrate; Preferably, Sm 0.5 Sr 0.5 Cu 0.2 Fe 0.8 O 3-δ The nitrates of the sintering aid elements of the powder include copper nitrate and iron nitrate nonahydrate; Preferably, Sm 0.5 Sr 0.5 Cu 0.2 Fe 0.8 O 3-δ The other element salts of the powder are strontium salts and samarium salts; Preferably, the strontium salt is strontium nitrate hexahydrate and the samarium salt is samarium nitrate.

[0013] The preparation of the modified SDC powder includes various methods. It can be prepared in the form of element double doping (CSF-SSCF, CSCO-SSCF, CSC-SSCF), or the sintering aid elements can be added in proportion after the SDC powder is prepared (xCo-SDC-SSCF, xCu -SSCF, xFe –SSCF, where x is the content and its value is less than or equal to 5).

[0014] And / or, in the preparation process in step S1, the molar ratio of the total metal ions, the amount of ethylenediaminetetraacetic acid, and the amount of citric acid in the materials is 1:1:1.3 - 1.7; Further, the heating and stirring temperature in step S1 is 85 °C - 90 °C, and the stirring speed is 100 - 200 rpm; And / or, adjusting the pH value in step S1 includes using ammonia water to adjust the pH value to 6 - 8; And / or, the drying temperature of the drying oven in step S1 is 140 - 160 °C, and the heat preservation time in the muffle furnace is 4 - 6 h.

[0015] Further, in step S2, the mass ratio of the modified SDC powder and the Sm 0.5 Sr 0.5 Cu 0.2 Fe 0.8 O 3-δ powder is: 1:1 - 1.2; In step S2, the modified SDC powder and the Sm 0.5 Sr 0.5 Cu 0.2 Fe 0.8 O 3-δ powder is ball-milled for 2 - 4 h with ethanol as the medium and then dried, and finally ground to obtain the final biphasic membrane powder.

[0016] Further, in step S3, high-temperature granulation is performed on the biphasic membrane powder, including adding a binder for granulation, dry-pressing into a circular sheet, heat-preserving in a muffle furnace for 4 - 6 h to obtain the final sintered membrane sheet, pressing and sintering with a fired SDC sheet during the firing process, and finally polishing the membrane with 480 - 520 mesh SiC sandpaper; And / or, the dry-pressing pressure is 150 - 200 MPa, and the pressure-holding time is 2 - 3 min; And / or, the mass ratio of the binder PVA to the biphasic membrane powder is 1 wt%, the heat-preserving temperature of the muffle furnace is 1100 °C - 1250 °C, and the time is 4 - 6 h; And / or, within the range of 200 °C before the heat-preserving time in the muffle furnace, the heating and cooling rate is set at 1 °C·min -1 , and within the remaining temperature range, the heating and cooling rate is set at 2 °C·min -1 ; And / or, the binder is PVA.

[0017] In summary, the fluorite phase with sintering aids and the mixed-conducting perovskite phase form a dual-phase membrane, which is a highly promising design concept for the trade-off between stability and oxygen permeability. It can not only break the limitation of electronic conduction in single-phase fluorite oxygen-permeable membranes but also weaken the limitation of oxygen ion conduction on dual-phase membranes. At the same time, there are still two theoretical advantages: on the one hand, the improvement of the conductivity behavior and the enhancement of the mixed-conducting ability due to the introduction of electronic conduction transform the fluorite phase from an oxygen ion conductor into a mixed conductor, thus expanding the active sites for the oxygen surface exchange reaction (OSER) to the entire surface of the membrane material. On the other hand, the blocking effect of electronic conduction in the fluorite phase will also be weakened. The designed high-flux novel MIEC1-MIEC2 dual-phase oxygen-permeable membrane achieves the trade-off between the stability of the oxygen-permeable membrane and high oxygen permeability.

[0018] Compared with the prior art, the high-flux MIEC1-MIEC2 dual-phase oxygen-permeable membrane material and its preparation method of the present invention have the following advantages: The present invention adds Co, Cu, and Fe sintering elements to the SDC fluorite phase to achieve microscopic regulation of the grain boundary and lattice structure, thereby improving its conductivity behavior. Based on the theoretical basis of the TPB expansion of OSER occurring in the dual-phase oxygen-permeable membrane, the reduction of oxygen ion conduction limitation, and the weakening of the electronic blocking effect, a high-flux novel MIEC1-MIEC2 dual-phase oxygen-permeable membrane material is designed. The prepared dual-phase oxygen-permeable membrane improves its oxygen permeability while maintaining the high stability of the dual-phase membrane, achieving the trade-off between stability and oxygen permeability, which is conducive to the popularization of the industrial application of oxygen-permeable membranes. At the same time, the oxygen-permeable membrane is prepared by a one-pot sol-gel method and formed by sheet dry pressing. The preparation process is simple and suitable for large-scale popularization and use. Brief Description of the Drawings

[0019] The drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: Figure 1 is the XRD pattern of different dual-phase oxygen-permeable membrane samples composed of modified SDC and SSCF in the embodiments of the present invention; Figure 2 is the SEM image, elemental EDS distribution, and particle size statistical chart of some dual-phase membranes prepared according to the method of the present invention in the embodiments of the present invention; Figure 3 is the EDS image of the surface morphology of some dual-phase membranes prepared according to the method of the present invention in the embodiments of the present invention and the distribution diagram of some elements of the sample; Figure 4Morphology, EDS surface scan, line scan data of each element, and element surface scan distribution of the 2Co-SDC-SSCF sintered membrane described in the embodiments of the present invention under TEM; Figure 5 (Grain morphology, HRTEM, and FFT images) of SDC, SSCF, and cobalt oxide phases in the 2Co-SDC-SSCF sample described in the embodiments of the present invention. Detailed implementation manners

[0020] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0021] The present invention will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0022] A high-throughput novel MIEC1-MIEC2 biphasic oxygen permeable membrane material, which material comprises Sm with mixed ionic and electronic conduction ability 0.5 Sr 0.5 Cu 0.2 Fe 0.8 O 3-δ (SSCF) and fluorite phase SDC modified by one of the sintering aid elements Cu, Co, or Fe.

[0023] The perovskite phase has mixed ionic and electronic conduction ability, but mainly conducts electricity by electrons; the electrical conductivity of the modified fluorite phase is optimized, and at the same time, the ability of electronic conduction is introduced, resulting in enhanced mixed conduction ability, thereby expanding the active sites for the occurrence of OSER, and the blocking effect of electronic conduction in the fluorite phase will also be weakened.

[0024] In the biphasic membrane, the mass ratio of the fluorite phase is between 50% and 70%.

[0025] Furthermore, in the modified fluorite phase material, the content of sintering aids such as Cu, Co, Fe, etc. added is generally less than 5 mol% to ensure its optimal electrical conductivity.

[0026] Provide a preparation method for a high-throughput novel MIEC1-MIEC2 biphasic oxygen permeable membrane material, (1) Calculate and accurately weigh the required cerium salts, samarium salts, iron salts, cobalt salts, and copper salts according to the material chemical formula, and add them to an appropriate amount of water, heat and stir until completely dissolved to obtain a metal ion solution; slowly add EDTA acid and citric acid, and adjust the pH of the solution with ammonia water, continuously heat and stir until the solution becomes gel-like, then place it in a drying oven for 12 h. After it shows a black fluffy state, take out the sample and heat it in a flat furnace to burn off the organic matter. After stirring without sparks, put it into a low-temperature muffle furnace for heat preservation to obtain the final required fluorite phase powder; (2) Calculate and accurately weigh the required strontium salts, samarium salts, iron salts, cobalt salts, etc. according to the material chemical formula, add them to an appropriate amount of water, heat and stir until completely dissolved to obtain a metal ion solution; slowly add EDTA acid and citric acid, adjust the pH of the solution with ammonia water, continuously heat and stir until the solution becomes gel-like, then place it in a drying oven for 12 h. After it shows a black and fluffy state, take out the sample and heat it in a plate furnace to burn out the organic matter. After stirring without sparks, place it in a low-temperature muffle furnace for heat preservation to obtain the final required fluorite-phase powder; (3) Mix the modified SDC powder and SSCF powder according to the mass ratio, ball-mill for 3 h with ethanol as the medium and then dry, and finally grind to obtain the final dual-phase membrane powder; (4) Mix the powder with the binder PVA and grind it evenly in an agate mortar. After drying in a drying oven, grind it again until it is fine. Weigh a certain amount of powder according to the thickness of the prepared membrane and place it in a stainless-steel mold. After spreading it evenly, keep it under pressure in an infrared press to obtain a formed green body, and then place it on an alumina plate and put it in a muffle furnace for heat preservation in an air atmosphere. Finally, polish it with 500-mesh sandpaper to obtain the final densified oxygen-permeable membrane sheet. Considering the influence of too fast heating and cooling on the membrane, the sintering system is selected in a segmented form. During this process, in order to prevent cracking and deformation, use the fired SDC sheet to press and sinter.

[0027] As a preferred technical solution, the cerium salt in step (1) is cerium nitrate hexahydrate (Ce(NO3)3·6H2O), the samarium salt is samarium nitrate hexahydrate (Sm(NO3)3·6H2O), the copper salt is copper nitrate (Cu(NO3)2), the cobalt salt is cobalt nitrate hexahydrate (Co(NO3)2·6H2O), and the iron salt is iron nitrate nonahydrate (Fe(NO3)3·9H2O).

[0028] The preparation of the modified SDC powder in step (1) includes various methods. It can be prepared in the form of element double doping (CSF-SSCF, CSCO-SSCF, CSC-SSCF), or auxiliary sintering elements can be added in proportion after the SDC powder is prepared (xCo-SDC-SSCF, xCu -SSCF, xFe –SSCF, where x is the content and its value is less than or equal to 5).

[0029] The heating and stirring temperature in step (1) is 85 °C - 90 °C, the stirring speed is 100 - 200 rpm. During the preparation process, the total amount of metal ions in the material: the amount of EDTA acid: the amount of citric acid = 1:1:1.5. The pH is adjusted to 6 - 8 with ammonia water, the drying oven temperature is 150 °C, and the muffle furnace heat preservation temperature is 550 °C for 5 h.

[0030] The strontium salt in step (2) is strontium nitrate (Sr(NO3)2), samarium nitrate hexahydrate (Sm(NO3)3·6H2O), the copper salt is copper nitrate (Cu(NO3)2), and the iron salt is iron nitrate nonahydrate (Fe(NO3)3·9H2O).

[0031] In step (4), the dry pressing pressure is 150 - 200 MPa, the pressure holding time is 2 - 3 min, the mass ratio of the binder PVA to the powder is 1 wt%, the heat preservation temperature in the high-temperature muffle furnace is 1100 °C - 1250 °C, and the time is 5 h. Within the range of 200 °C before the heat preservation time, the heating and cooling rate is set at 1 °C·min -1 , and the heating and cooling rate is set at 2 °C·min in the remaining temperature range -1 .

[0032] Example 1 Calculate and accurately weigh the required cerium nitrate hexahydrate (Ce(NO3)3·6H2O), samarium nitrate hexahydrate (Sm(NO3)3·6H2O), copper nitrate (Cu(NO3)2), and one of the sintering aids cobalt nitrate hexahydrate (Co(NO3)2·6H2O) or iron nitrate nonahydrate (Fe(NO3)3·9H2O) according to the material chemical formula described.

[0033] According to the ratio of the total amount of metal ions in the material: the amount of EDTA acid: the amount of citric acid = 1:1:1.5 during the preparation process, slowly add EDTA acid and citric acid, and adjust the pH of the solution to 6 - 8 with ammonia water. Continuously heat and stir at a temperature of 85 °C - 90 °C until the solution becomes gel-like, then place it in a drying oven at 150 °C for 12 h. After it becomes black and fluffy, take out the sample and heat it in a flat furnace to burn off the organic matter. After stirring until there are no sparks, put it into a low-temperature muffle furnace and keep it at 550 °C for 5 h to obtain the final required fluorite-phase powder.

[0034] Calculate and accurately weigh the required strontium nitrate (Sr(NO3)2), samarium nitrate hexahydrate (Sm(NO3)3·6H2O), and copper nitrate (Cu(NO3)2); cobalt nitrate hexahydrate (Co(NO3)2·6H2O), iron nitrate nonahydrate (Fe(NO3)3·9H2O). Prepare perovskite powder; mix the modified SDC powder and SSCF powder according to the mass ratio, ball mill for 3 h with ethanol as the medium and then dry, and finally grind to obtain the final biphasic membrane powder.

[0035] The powder was mixed with the binder PVA at 1 wt% and placed in an agate mortar for uniform grinding. After drying in an oven, it was reground until fine. A certain amount of powder was weighed according to the thickness of the prepared membrane and placed in a stainless-steel mold. After spreading evenly, it was pressed in an infrared press at 150 - 200 MPa for 2 - 3 min to obtain a green compact. Then it was placed on an alumina plate and put into a muffle furnace, and kept at 1100 ℃ - 1250 ℃ for 5 h in an air atmosphere. Finally, it was polished with 500-mesh sandpaper to obtain the final densified oxygen-permeable membrane sheet. Considering the influence of too fast heating and cooling rates on the membrane, the sintering regime was selected in a segmented form. Within 200 ℃ before the holding time, the heating and cooling rates were set at 1 ℃·min -1 , and the heating and cooling rates were set at 2 ℃·min in the remaining temperature ranges -1 . During this process, in order to prevent cracking and deformation, the fired SDC sheet was used for pressing and sintering

[0036] As Figure 1 shown, this example adopted a high-flux novel MIEC1-MIEC2 dual-phase oxygen-permeable membrane material and its preparation method to prepare dual-phase oxygen-permeable membranes with different sintering aids and different addition methods. All the dual-phase oxygen-permeable membrane materials contained a fluorite phase and a perovskite phase, and the two phases were well-matched, and no obvious impurity peaks were found. This indicates that for the prepared dual-phase oxygen-permeable membrane, the two phases are compatible with each other and coexist stably, without other adverse reactions. The good compatibility comes from the fact that the two phases contain the same rare-earth element Sm, and Sr has a low solubility energy in the perovskite lattice

[0037] As Figure 2 shown, for the surface SEM image, element EDS distribution map and particle size statistical chart of the dual-phase oxygen-permeable membrane prepared in this example, the particles are closely packed, indicating the high density of the sintered membrane. The average grain size of several samples is between 1.71 μm and 2.45 μm. Although the sintering temperature of the dual-phase membrane is lower than that of fluorite, the grain size does not decrease. The increase in grain size is mainly due to the promotion of the perovskite phase on the fluorite phase grains, which also reflects its sintering aid effect on the SDC fluorite phase. The SEM image intuitively reflects the difference between the two phases. The large particles are the SDC fluorite phase, and the grain size is roughly in the range of 3 μm - 6 μm. The smaller particles are the SSCF perovskite phase, and the grain size range is 0.5 μm - 2 μm. The two types of particles representing different phases are evenly distributed in the membrane body, respectively forming a three-dimensional connected network for the conduction of oxygen ions (lattice oxygen) and electrons, and combining with the surface exchange (adsorption and dissociation) of oxygen to achieve the oxygen permeation effect. From the element EDS distribution map, the distribution profiles of the two phases can also be seen. The SDC representative element Ce and the SSCF representative elements Sr and Fe clearly reflect the distribution of the two phases. Sm and O are more evenly distributed because they exist in both phases

[0038] As shown Figure 3 in the surface scan EDS images of several sintered samples of the dual-phase oxygen permeable membrane prepared in this example, the phase particles show significantly different color distributions due to elemental differences, and correspond to the distribution trends of Ce, Sr, and Fe. The green color comes from the element signals of Ce, Sm, and O, while the purple color comes from the overlap of Sm, Sr, Cu, Fe, and O. The EDS signal intensity corresponds to the mass ratio of the two phases, indicating no obvious reaction, further demonstrating good chemical compatibility between the two phases of the prepared composite ceramic material. At the same time, trace amounts of Ce are detected in the perovskite phase, and trace amounts of perovskite elements are detected in the SDC phase, indicating that there is a small amount of elemental self-diffusion between the two phases. This self-regulation of the chemical composition between the two phases is attributed to the different chemical potentials of the elements in the two phases.

[0039] After sintering to densification, grains with two-phase close arrangement are formed, ensuring the bulk conduction of ions and electrons during the oxygen permeation process. As shown Figure 3 in the IC-EC type dual-phase membrane, the TPB only exists at position A at the junction of the two phases, while in the IC-MIEC type dual-phase membrane, the TPB exists at A and on the surface B of the perovskite phase with mixed conduction ability. The addition of the sintering aid enhances the mixed conduction ability of the SDC fluorite phase, turning the dual-phase membrane into a MIEC1-MIEC2 dual mixed conduction material, thus expanding the TPB from A and B to the surface C of the modified SDC phase with mixed conduction ability. The improvement of the electron conduction ability of the fluorite phase reduces the blocking effect at C when electrons conduct along the L line of the perovskite phase.

[0040] As shown Figure 4 in the morphology of the 2Co-SDC-SSCF dual-phase oxygen permeable membrane prepared in this example and the surface / line scan element distribution in some areas in the high-angle annular dark field (HAADF-STEM) mode, the uniform distribution of Co elements indicates that the added sintering aid elements may exist in both phases, partially dissolve into the SDC lattice at high temperature, and at the same time, Co elements at the remaining grain boundaries will also partially enter the SSCF perovskite lattice.

[0041] As shown Figure 5 in the grain morphology of each phase, HRTEM, and the diffraction patterns obtained by FFT of the 2Co-SDC-SSCF dual-phase oxygen permeable membrane prepared in this example. According to the calibration results of the diffraction patterns, in addition to SDC (PDF#75-0158) in the matrix, the SSCF perovskite phase (PDF#43-0226) is also detected. Under the zone axis of

[010] , taking the (001), (101), and (100) crystal planes as the minimum unit, the corresponding interplanar spacings are 3.88 Å, 2.69 Å, and 3.88 Å respectively, and the included angles are all 45°. The existence of the two phases is consistent with the XRD analysis results. The slight decrease in the interplanar spacings of the SDC and SSCF matrix crystal planes indicates the solid solution of Co elements and elemental self-diffusion at high temperature.

[0042] The perovskite phase of the material of this application is Sm with mixed ionic and electronic conduction (mainly electronic conduction). 0.5 Sr 0.5 Cu 0.2 Fe 0.8 O 3-δ (SSCF). The fluorite phase is based on Ce 0.8 Sm 0.2 O 2-δ (SDC), and different amounts of sintering aids such as Co, Cu or Fe are introduced in different ways to improve its conductivity behavior. The fluorite phase is the main conductor of oxygen ion conduction in the IC-MIEC (oxygen ion conduction - mixed ionic and electronic conduction) type dual-phase oxygen permeable membrane. Improving its conductivity performance and electronic conductivity ability can not only weaken the oxygen ion conduction limitation in the dual-phase membrane, but also extend the triple-phase boundary (TPB) where the oxygen surface exchange reaction (OSER) occurs to the entire membrane surface, and at the same time reduce the blocking effect of electronic conduction in the fluorite phase. Finally, a new type of MIEC1-MIEC2 type dual-phase oxygen permeable membrane is prepared, which can improve its oxygen permeation performance to a certain extent while ensuring the high stability of the dual-phase oxygen permeable membrane, and solve the bottleneck problem of the trade-off between the oxygen permeation rate and stability of the oxygen permeable membrane.

[0043] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A high-throughput MIEC1-MIEC2 biphasic oxygen permeable membrane material, characterized in that: Including Sm with mixed ionic and electronic conduction capabilities 0.5 Sr 0.5 Cu 0.2 Fe 0.8 O 3-δ And fluorite-phase SDC modified by sintering aid elements.

2. The high-throughput MIEC1-MIEC2 biphasic oxygen permeable membrane material according to claim 1, characterized in that: The sintering aid elements include one or more of Cu, Co, or Fe; Preferably, the sintering aid includes one or more of cerium nitrate hexahydrate, samarium nitrate hexahydrate, copper nitrate, cobalt nitrate hexahydrate, or iron nitrate nonahydrate.

3. A high-throughput MIEC1-MIEC2 biphasic oxygen permeable membrane material according to claim 1, characterized in that: The content of the sintering aid element in a high-throughput MIEC1-MIEC2 dual-phase oxygen permeable membrane material is at least 5%.

4. A high-throughput MIEC1-MIEC2 biphasic oxygen permeable membrane material according to claim 1, characterized in that: The content of SDC in a high-throughput MIEC1-MIEC2 dual-phase oxygen permeable membrane material is 50%-70%.

5. The preparation method of a high-throughput MIEC1-MIEC2 dual-phase oxygen permeable membrane material according to claims 1-4, characterized in that: It includes the following steps: S1: Prepare modified SDC powder and Sm 0.5 Sr 0.5 Cu 0.2 Fe 0.8 O 3-δ powder respectively by sol-gel method; S2: Mix the modified SDC powder and the Sm 0.5 Sr 0.5 Cu 0.2 Fe 0.8 O 3-δ powders, and obtain the dual-phase membrane powder after grinding and drying; S3: Granulate the dual-phase membrane powder at high temperature to obtain a high-throughput MIEC1-MIEC2 dual-phase oxygen permeable membrane material.

6. The preparation method of a high-throughput MIEC1-MIEC2 biphasic oxygen permeable membrane material according to claim 5, wherein: The modified SDC powder or Sm in step S1 0.5 Sr 0.5 Cu 0.2 Fe 0.8 O 3-δ The preparation of the powder comprises the following steps: Place the nitrates of the sintering aid elements and other element salts in deionized water, heat and stir. After complete dissolution, add ethylenediaminetetraacetic acid and citric acid monohydrate, and adjust the pH value. After continuous heating and stirring, dry in an oven and keep warm in a muffle furnace to obtain the modified SDC powder.

7. The preparation method of a high-throughput MIEC1-MIEC2 dual-phase oxygen permeable membrane material according to claim 6, wherein: The nitrates of the sintering aid elements in the modified SDC powder include copper nitrate, cobalt nitrate hexahydrate, and iron nitrate nonahydrate; Preferably, the other element salts of the modified SDC powder are cerium salts and samarium salts; Preferably, the cerium salt is cerium nitrate hexahydrate and the samarium salt is samarium nitrate hexahydrate; Preferably, Sm 0.5 Sr 0.5 Cu 0.2 Fe 0.8 O 3-δ The nitrates of the sintering aid elements of the powder include copper nitrate and iron(III) nitrate nonahydrate; Preferably, Sm 0.5 Sr 0.5 Cu 0.2 Fe 0.8 O 3-δ The other element salts of the powder are strontium salts and samarium salts; Preferably, the strontium salt is strontium nitrate hexahydrate and the samarium salt is samarium nitrate.

8. The preparation method of a high-throughput MIEC1-MIEC2 biphasic oxygen permeable membrane material according to claim 6, characterized in that: In the preparation process of step S1, the molar ratio of the total metal ions of the material, the amount of ethylenediaminetetraacetic acid, and the amount of citric acid is 1:1:1.3-1.7; The heating and stirring temperature in step S1 is 85 °C - 90 °C, and the stirring speed is 100-200 rpm; And / or, adjusting the pH value in step S1 includes using ammonia water to adjust the pH value to 6-8; And / or, the drying temperature of the oven in step S1 is 140-160 °C, and the heat preservation time in the muffle furnace is 4-6 h.

9. The preparation method of a high-throughput MIEC1-MIEC2 biphasic oxygen-permeable membrane material according to claim 5, characterized in that: In step S2, the mass ratio of the modified SDC powder to the Sm 0.5 Sr 0.5 Cu 0.2 Fe 0.8 O 3-δ powder is: 1: 1 - 1.2; In step S2, the modified SDC powder and Sm 0.5 Sr 0.5 Cu 0.2 Fe 0.8 O 3-δ powder are ball-milled with ethanol as the medium for 2 - 4 h and then dried, and finally ground to obtain the final powder for the dual-phase membrane.

10. The preparation method of a high-throughput MIEC1-MIEC2 biphasic oxygen permeable membrane material according to claim 5, characterized in that: In step S3, granulating the dual-phase membrane powder at high temperature includes adding a binder for granulation, dry-pressing into a circular sheet, keeping warm in a muffle furnace for 4-6 h to obtain the final sintered membrane sheet, pressing and sintering with a fired SDC sheet during the firing process, and finally polishing the membrane with 480-520 mesh SiC sandpaper; And / or, the dry-pressing pressure is 150-200 MPa, and the pressure-holding time is 2-3 min; And / or, the mass ratio of the binder PVA to the dual-phase membrane powder is 1 wt%, the heat preservation temperature of the muffle furnace is 1100 °C - 1250 °C, and the time is 4-6 h; And / or, within the range of 200 °C before the holding time of the muffle furnace, the heating and cooling rate is set at 1 °C·min -1 , and the heating and cooling rate is set at 2 °C·min within the remaining temperature range -1 ; And / or, the binder is PVA.

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