Composite material as well as preparation method and application thereof

Abstract

The invention relates to a composite material and a preparation method and application thereof, and belongs to the technical field of electrolytic hydrogen production. The composite material comprises a La-based perovskite material and a composite material of oxides of VIB group elements, according to the composite material, the VIB group elements have various valence states, and the valence states of common oxidants of the VIB group elements comprise + 6 and + 4, so that the composite material has certain valence changing capacity, has better interaction with active oxygen, and assists in completing the oxidation process of oxygen ions; and the interface member of the oxide of the VIB group element and the La-based perovskite material can change the electronic structure of the surface of the La-based perovskite material, so that the oxygen evolution reaction activity of the La-based perovskite material is improved, and the purpose of improving the poor catalytic activity of the La-based perovskite material is achieved.

Description

Technical Field

[0001] This application relates to the technical field of electrolytic hydrogen production, and particularly relates to a composite material, a preparation method thereof, and an application thereof. Background Art

[0002] High-temperature electrolytic hydrogen production is a green, clean, and efficient electrolytic hydrogen production technology. In the high-temperature electrolytic hydrogen production process (SOEC), the catalytic activity of the oxygen electrode is a key factor affecting the reaction efficiency. La-based perovskite materials are a type of widely used oxygen electrode catalytic materials. Among them, in the La-based perovskite materials, La 0.6 Sr 0.4 FeO3 perovskite material has good material stability, but the catalytic activity of the oxygen evolution reaction is relatively poor and needs to be further improved. Summary of the Invention

[0003] This application provides a composite material, a preparation method thereof, and an application thereof to improve the problem of poor catalytic activity of La-based perovskite materials.

[0004] In a first aspect, this application provides a composite material, which includes a composite material of a La-based perovskite material and an oxide of a Group VI B element.

[0005] As an optional implementation manner, the La-based perovskite material includes La 0.6 Sr 0.4 FeO3.

[0006] As an optional implementation manner, the oxide of the Group VI B element includes Mo y W 1-y O 3-d , where y is 0.1 to 0.9 and d is 0 to 0.05.

[0007] As an optional implementation manner, the oxide of the Group VI B element includes Mo y W 1-y O 3-d , where y is 0.3 to 0.7 and d is 0 to 0.05.

[0008] As an optional implementation manner, the oxide of the Group VI B element includes Mo y W 1-y O 3-d , where y is 0.4 to 0.6 and d is 0 to 0.05.

[0009] As an optional implementation manner, the mass ratio of the oxide of the Group VI B element to the La-based perovskite material is 0.01 to 0.3.

[0010] As an alternative embodiment, the mass ratio of the oxide of Group VIB element to the La-based perovskite material is 0.02 to 0.1.

[0011] As an alternative embodiment, the mass ratio of the oxide of Group VIB element to the La-based perovskite material is 0.04 to 0.06.

[0012] In a second aspect, the present application provides a method for preparing a composite material, the method comprising:

[0013] Obtaining a La-based perovskite material;

[0014] Compounding the La-based perovskite material with the oxide of Group VIB element to obtain a composite material.

[0015] As an alternative embodiment, the obtaining of the La-based perovskite material includes:

[0016] Dissolving lanthanum nitrate hexahydrate, strontium nitrate and iron nitrate nonahydrate in a solvent to obtain a first mixed solution;

[0017] Mixing the first mixed solution, an ammonia aqueous solution of EDTA and citric acid, and then performing evaporation to obtain a first gel;

[0018] Performing a first baking on the first gel, and then performing a first heat preservation treatment to obtain the La-based perovskite material La 0.6 Sr 0.4 FeO3.

[0019] As an alternative embodiment, the temperature of the first baking is 200 to 300 °C; and / or

[0020] The time of the first baking is 9 to 11 hours.

[0021] As an alternative embodiment, the temperature of the first baking is 230 to 270 °C; and / or

[0022] The time of the first baking is 9.5 to 10.5 hours.

[0023] As an alternative embodiment, the temperature of the first heat preservation treatment is 800 to 1000 °C; and / or

[0024] The time of the first heat preservation treatment is 4 to 6 hours.

[0025] As an alternative embodiment, the temperature of the first heat preservation treatment is 850 to 950 °C; and / or

[0026] The time of the first heat preservation treatment is 4.5 to 5.5 hours.

[0027] As an alternative embodiment, the compounding of the La-based perovskite material and the oxide of Group VIB element to obtain a composite material includes:

[0028] Dissolve ammonium metatungstate and ammonium molybdate in a solvent to obtain a second mixed solution;

[0029] Mix the second mixed solution, an aqueous ammonia solution of EDTA and citric acid, then add the La-based perovskite material and evaporate to obtain a second gel;

[0030] Perform a second baking on the second gel, and then perform a second heat preservation treatment to obtain a composite material.

[0031] As an alternative embodiment, the temperature of the second baking is 200 - 300 °C; and / or

[0032] The time of the second baking is 9 - 11 hours.

[0033] As an alternative embodiment, the temperature of the second baking is 230 - 270 °C; and / or

[0034] The time of the second baking is 9.5 - 10.5 hours.

[0035] As an alternative embodiment, the temperature of the second heat preservation treatment is 400 - 600 °C; and / or

[0036] The time of the second heat preservation treatment is 4 - 6 hours.

[0037] As an alternative embodiment, the temperature of the second heat preservation treatment is 450 - 550 °C; and / or

[0038] The time of the second heat preservation treatment is 4.5 - 5.5 hours.

[0039] In a third aspect, the present application provides an application of a composite material. The composite material includes the composite material described in the first aspect or the composite material prepared by the method described in the second aspect. The application includes using the composite material for electrolytic hydrogen production.

[0040] The above technical solutions provided by the embodiments of the present application have the following advantages compared with the prior art:

[0041] The composite material provided by the embodiment of the present application utilizes the fact that group VI B elements have multiple valences, and their common oxidation valences include +6 and +4. Therefore, they have a certain ability to change valence, have a good interaction with active oxygen, assist in completing the oxidation process of oxygen ions, and the interface structure between the oxides of group VI B elements and the La-based perovskite material can change the electronic structure on the surface of the La-based perovskite material, thereby enhancing the oxygen evolution reaction activity of the La-based perovskite material and achieving the purpose of improving the problem of poor catalytic activity of the La-based perovskite material. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The drawings herein are incorporated into the specification and form a part of this specification, showing embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application.

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0044] Figure 1 It is a flowchart of the method provided by the embodiment of the present application;

[0045] Figure 2 It is a scanning electron microscope image of the composite material provided by Embodiment 1 of the present application;

[0046] Figure 3 It is a transmission electron microscope image and an EDS element distribution map of the composite material provided by Embodiment 1 of the present application;

[0047] Figure 4 It is a powder X-ray diffraction pattern of the composite materials provided by Embodiment 1, Comparative Example 1, and Comparative Example 2 of the present application;

[0048] Figure 5 It is an electrolysis performance diagram of the composite materials provided by Embodiment 1, Comparative Example 1, and Comparative Example 2 of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0049] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments in the present application belong to the scope of protection of the present application.

[0050] Unless otherwise specified, all kinds of raw materials, reagents, instruments and equipment used in this application can be obtained through market purchase or can be prepared by existing methods.

[0051] High-temperature electrolytic hydrogen production is a green, clean and efficient electrolytic hydrogen production technology. In the process of high-temperature electrolytic hydrogen production (SOEC), the catalytic activity of the oxygen electrode is a key factor affecting the reaction efficiency. La-based perovskite materials are a kind of widely used oxygen electrode catalytic materials. Among them, in La-based perovskite materials, La 0.6 Sr 0.4 FeO3 perovskite material has good material stability but relatively poor catalytic activity for oxygen evolution reaction, which needs to be further improved.

[0052] Among transition metals, Mo and W, as group VI B elements, have multiple valence states, and their common oxidation states include +6 and +4. This enables Mo y W 1-y O 3-d to have a certain variable valence ability, have good interaction with active oxygen, and assist in completing the oxidation process of oxygen ions. In addition, Mo y W 1-y O 3-d The construction of the interface with La 0.6 Sr 0.4 FeO3 can change the electronic structure on the surface of La 0.6 Sr 0.4 FeO3, thereby enhancing the oxygen evolution reaction activity of La 0.6 Sr 0.4 FeO3.

[0053] This application provides a method for preparing La 0.6 Sr 0.4 FeO3-x%Mo y W 1-y O 3-d catalyst. Through the interaction of the composite electrode interface, Mo y W 1-y O 3-d changes the electronic structure of La 0.6 Sr 0.4 FeO3; The variable valence process of Mo y W 1-y O 3-d assists in completing the oxidation process of oxygen ions, thereby enhancing its high-temperature electrolytic oxygen evolution reaction activity.

[0054] The embodiment of this application provides a composite material, and the composite material includes a composite material of La-based perovskite material and an oxide of group VI B element.

[0055] This composite material utilizes the fact that group VI B elements have multiple valence states, and their common oxidation states include +6 and +4. Therefore, it has a certain ability to change valence, has a good interaction with active oxygen, and assists in completing the oxidation process of oxygen ions. Moreover, the interface structure between the oxide of group VI B elements and the La-based perovskite material can change the electronic structure on the surface of the La-based perovskite material, thereby enhancing the oxygen evolution reaction activity of the La-based perovskite material and achieving the purpose of improving the problem of poor catalytic activity of the La-based perovskite material.

[0056] In some embodiments, the La-based perovskite material includes La 0.6 Sr 0.4 FeO3. The oxide of the group VI B element includes Mo y W 1-y O 3-d , where y is 0.1 to 0.9 and d is 0 to 0.05. Further, the oxide of the group VI B element includes Mo y W 1-y O 3-d , where y is 0.3 to 0.7 and d is 0 to 0.05. Even further, the oxide of the group VI B element includes Mo y W 1-y O 3-d , where y is 0.4 to 0.6 and d is 0 to 0.05. Exemplarily, y can be 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, or 0.9, etc., and it can also be any value within the range of 0.1 to 0.9. D can be 0, 0.001, 0.005, 0.01, 0.015, 0.02, 0.025, 0.03, 0.035, 0.04, 0.045, or 0.05, etc., and it can also be any value within the range of 0 to 0.05.

[0057] This composite material is achieved by: ① adjusting the surface charge structure. In this patent, by constructing the composite structure of La 0.6 Sr 0.4 FeO3-x%Mo y W 1- y O 3-d , the surface charge structure of La 0.6 Sr 0.4 FeO3 is adjusted, thereby enhancing its oxygen evolution reaction activity; ② Mo y W 1-y O 3-d directly participates in the oxygen evolution reaction to enhance the catalytic activity. The oxygen ions of the fuel electrode migrate through the electrolyte to La 0.6 Sr 0.4The surface of FeO3; oxygen ions oxidize the low-valence IV metal in Mo y W 1-y O 3-d from the low valence state to the high valence state VI; Mo y W 1-y O 3-d The high valence state VI in then reduces to precipitate oxygen and returns to the low valence state IV, thus completing the entire catalytic cycle. This realizes improving the catalytic activity and reducing the electrolysis energy consumption.

[0058] In some embodiments, the mass ratio of the oxide of the Group VI B element to the La-based perovskite material is 0.01 to 0.3. Further, the mass ratio of the oxide of the Group VI B element to the La-based perovskite material is 0.02 to 0.1. Still further, the mass ratio of the oxide of the Group VI B element to the La-based perovskite material is 0.04 to 0.06. Exemplarily, the mass ratio of the oxide of the Group VI B element to the La-based perovskite material can be 0.01, 0.05, 0.1, 0.15, 0.2, 0.25 or 0.3, etc., and it can also be any value within the range of 0.01 to 0.3.

[0059] As Figure 1 shown, based on a general inventive concept, the embodiments of the present application also provide a preparation method of a composite material, and the method includes:

[0060] S1. Obtain the La-based perovskite material;

[0061] In some embodiments, the obtaining of the La-based perovskite material includes:

[0062] S1.1. Dissolve lanthanum nitrate hexahydrate, strontium nitrate and iron nitrate nonahydrate in a solvent to obtain a first mixed solution;

[0063] S1.2. Mix the first mixed solution, the ammonia aqueous solution of EDTA and citric acid, and then evaporate to obtain a first gel;

[0064] S1.3. Perform a first baking on the first gel, and then perform a first heat preservation treatment to obtain the La-based perovskite material La 0.6 Sr 0.4 FeO3.

[0065] In some embodiments, the temperature of the first baking is 200 to 300 °C; the time of the first baking is 9 to 11 hours. Further, the temperature of the first baking is 230 to 270 °C; the time of the first baking is 9.5 to 10.5 hours. Exemplarily, the temperature of the first baking can be 200 °C, 210 °C, 220 °C, 230 °C, 240 °C, 250 °C, 260 °C, 270 °C, 280 °C, 290 °C or 300 °C, etc., and it can also be any value within the range of 200 to 300 °C. The time of the first baking can be 9 hours, 9.2 hours, 9.4 hours, 9.6 hours, 9.8 hours, 10 hours, 10.2 hours, 10.4 hours, 10.6 hours, 10.8 hours or 11 hours, etc., and it can also be any value within the range of 9 to 11 hours.

[0066] In some embodiments, the temperature of the first heat preservation treatment is 800 to 1000 °C; the time of the first heat preservation treatment is 4 to 6 hours. The temperature of the first heat preservation treatment is 850 to 950 °C; the time of the first heat preservation treatment is 4.5 to 5.5 hours. Exemplarily, the temperature of the first heat preservation treatment can be 800 °C, 810 °C, 820 °C, 830 °C, 840 °C, 850 °C, 860 °C, 870 °C, 880 °C, 890 °C, 900 °C, 910 °C, 920 °C, 930 °C, 940 °C, 950 °C, 960 °C, 970 °C, 980 °C, 990 °C or 1000 °C, etc., and it can also be any value within the range of 800 to 1000 °C. The time of the first heat preservation treatment can be 4 hours, 4.1 hours, 4.2 hours, 4.3 hours, 4.4 hours, 4.5 hours, 4.6 hours, 4.7 hours, 4.8 hours, 4.9 hours, 5 hours, 5.1 hours, 5.2 hours, 5.3 hours, 5.4 hours, 5.5 hours, 5.6 hours, 5.7 hours, 5.8 hours, 5.9 hours or 6 hours, etc., and it can also be any value within the range of 4 to 6 hours.

[0067] Specifically, in this embodiment, regarding La 0.6 Sr 0.4 FeO3 synthesis: First, a total of 5 g of lanthanum nitrate hexahydrate, strontium nitrate, and iron nitrate nonahydrate powders are dissolved in 10 ml of water according to the stoichiometric ratio. After stirring and dissolving, 20 ml of 50% EDTA ammonia aqueous solution is added. After stirring and dissolving, 10 g of citric acid is added. Stir at 80 °C until the solution evaporates to form a gel. After taking out the gel, bake it at 250 °C for 10 hours to form a black powder coke-like powder, and then keep it at 900 °C for 5 h to form La 0.6 Sr 0.4 FeO3 powder, grind it for 10 minutes and store it after drying.

[0068] S2. Combine the La-based perovskite material and the oxide of Group VIB element to obtain a composite material.

[0069] In some embodiments, the combining the La-based perovskite material and the oxide of Group VIB element to obtain a composite material includes:

[0070] S2.1. Dissolve ammonium metatungstate and ammonium molybdate in a solvent to obtain a second mixed solution;

[0071] S2.2. Mix the second mixed solution, the ammonia aqueous solution of EDTA and citric acid, then add the La-based perovskite material and evaporate to obtain a second gel;

[0072] S2.3. Perform a second baking on the second gel, and then perform a second heat preservation treatment to obtain a composite material.

[0073] In some embodiments, the temperature of the second baking is 200 - 300 °C; the time of the second baking is 9 - 11 hours. Further, the temperature of the second baking is 230 - 270 °C; the time of the second baking is 9.5 - 10.5 hours. Exemplarily, the temperature of the second baking can be 200 °C, 210 °C, 220 °C, 230 °C, 240 °C, 250 °C, 260 °C, 270 °C, 280 °C, 290 °C or 300 °C, etc., and it can also be any value within the range of 200 - 300 °C. The time of the second baking can be 9 hours, 9.2 hours, 9.4 hours, 9.6 hours, 9.8 hours, 10 hours, 10.2 hours, 10.4 hours, 10.6 hours, 10.8 hours or 11 hours, etc., and it can also be any value within the range of 9 - 11 hours.

[0074] In some embodiments, the temperature of the second heat preservation treatment is 400 - 600 °C; the time of the second heat preservation treatment is 4 - 6 hours. Further, the temperature of the second heat preservation treatment is 450 - 550 °C; the time of the second heat preservation treatment is 4.5 - 5.5 hours. Exemplarily, the temperature of the second heat preservation treatment can be 400 °C, 410 °C, 420 °C, 430 °C, 440 °C, 450 °C, 460 °C, 470 °C, 480 °C, 490 °C, 500 °C, 510 °C, 520 °C, 530 °C, 540 °C, 550 °C, 560 °C, 570 °C, 580 °C, 590 °C or 600 °C, etc., and it can also be any value within the range of 400 - 600 °C. The time of the second heat preservation treatment can be 4 hours, 4.1 hours, 4.2 hours, 4.3 hours, 4.4 hours, 4.5 hours, 4.6 hours, 4.7 hours, 4.8 hours, 4.9 hours, 5 hours, 5.1 hours, 5.2 hours, 5.3 hours, 5.4 hours, 5.5 hours, 5.6 hours, 5.7 hours, 5.8 hours, 5.9 hours or 6 hours, etc., and it can also be any value within the range of 4 - 6 hours.

[0075] Specifically, in this embodiment, regarding La 0.6 Sr 0.4 FeO3 - 5% Mo 0.5 W 0.5 O 3-d Synthesis: Dissolve a total of 0.91 g of ammonium metatungstate and 0.72 g of ammonium molybdate in 10 ml of water. After stirring and dissolving, add 10 ml of 50% ammonia aqueous solution of EDTA. After stirring and dissolving, add 1 g of citric acid. Add 10 g of La 0.6 Sr 0.4 FeO3 powder into the solution to form a suspension. Stir at 80 °C until the solution evaporates to form a gel. After taking out the gel, bake it at 250 °C for 10 hours to form a black powder coke-like powder, and then keep it at 500 °C for 5 h to form La 0.6 Sr 0.4 FeO3 - Mo 0.5 W 0.5 O 3-d powder, grind it for 10 minutes and store it after drying.

[0076] This method is realized based on the above composite material. For the specific content of the composite material, reference can be made to the above embodiments. Since this method adopts some or all of the technical solutions of the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be elaborated one by one here.

[0077] This method synthesizes La 0.6 Sr 0.4 FeO3 - x% Mo by a one-step sol-gel synthesis methody W 1-y O 3-d Composite material. Applying it to the high-temperature electrolysis of water can improve the electrode catalytic performance and reduce the reaction overpotential.

[0078] Based on a general inventive concept, an embodiment of the present application also provides an application of a composite material, where the composite material includes the composite material provided above or the composite material prepared by the method provided above, and the application includes using the composite material for hydrogen production by electrolysis.

[0079] This application is implemented based on the above composite material or method. For the specific content of the composite material or method, reference can be made to the above embodiments. Since this application adopts some or all of the technical solutions of the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be elaborated one by one here.

[0080] Specifically, in this embodiment, regarding La 0.6 Sr 0.4 FeO3 - 5% Mo 0.5 W 0.5 O 3-d Preparation of the electrode layer: Mix 2 ml of a 6% ethyl cellulose solution in terpineol with 2 g of La 0.6 Sr 0.4 FeO3 - Mo 0.5 W 0.5 O 3-d powder and ball mill for 5 h to obtain an electrode paste. Screen-print the electrode paste on the surface of the electrolyte of a half electrolytic cell three times repeatedly. Put the obtained half cell into a constant temperature heating at 950 °C for 2 h, and after cooling to room temperature, obtain a full electrolytic cell with a La 0.6 Sr 0.4 FeO3 - Mo 0.5 W 0.5 O 3-d oxygen electrode layer.

[0081] The usage conditions of this composite material include: at 750 °C, 80% water vapor concentration, and an electrolysis voltage of 1.29 V at 1 A / cm2.

[0082] The following further elaborates the present application in combination with specific embodiments. It should be understood that these embodiments are only used to illustrate the present application and not to limit the scope of the present application. For the experimental methods without specific conditions indicated in the following embodiments, they are usually determined according to national standards. If there is no corresponding national standard, they are carried out according to general international standards, conventional conditions, or the conditions recommended by the manufacturer.

[0083] Example 1

[0084] A method for preparing a full electrolytic cell, the method comprising:

[0085] Preparation of composite material:

[0086] La 0.6 Sr 0.4 Synthesis of LaSrFeO3: First, a total of 5 g of lanthanum nitrate hexahydrate, strontium nitrate, and iron nitrate nonahydrate powders were dissolved in 10 ml of water according to the stoichiometric ratio. After stirring and dissolving, 20 ml of 50% ammonia solution of EDTA was added. After stirring and dissolving, 10 g of citric acid was added. Stir at 80 °C until the solution evaporates to form a gel. After taking out the gel, it was baked at 250 °C for 10 hours to form a black powder in the form of coke powder, and then kept at 900 °C for 5 h to form La1-xSrxFeO3 powder, which was ground for 10 minutes and stored after drying.

[0087] La 0.6 Sr 0.4 LaSrFeO3 - 5% Mo 0.5 W 0.5 O 3-d Synthesis: 0.33 g of ammonium metatungstate and 0.26 g of ammonium molybdate were dissolved in 10 ml of water. After stirring and dissolving, 10 ml of 50% ammonia solution of EDTA was added. After stirring and dissolving, 1 g of citric acid was added. 10 g of La 0.6 Sr 0.4 LaSrFeO3 powder was added to the solution to form a suspension. Stir at 80 °C until the solution evaporates to form a gel. After taking out the gel, it was baked at 250 °C for 10 hours to form a black powder in the form of coke powder, and then kept at 500 °C for 5 h to form La 0.6 Sr 0.4 LaSrFeO3 - 5% Mo 0.5 W 0.5 O 3-d powder, which was ground for 10 minutes and stored after drying.

[0088] Preparation of the above composite material into a solid electrolytic cell:

[0089] 2 ml of a 6% ethyl cellulose solution in terpineol was ball - milled with 2 g of La 0.6 Sr 0.4 LaSrFeO3 - 5% Mo 0.5 W 0.5 O 3-d powder for 5 h to prepare an electrode paste. The electrode paste was screen - printed on the electrolyte surface of the half - electrolytic cell three times repeatedly. The obtained half - cell was placed in a furnace heated to 950 °C and kept at a constant temperature for 2 h, and then cooled to room temperature to obtain a solid electrolytic cell with a La 0.6 Sr 0.4 LaSrFeO3 - 5% Mo 0.5 W 0.5 O 3-d oxygen electrode layer.

[0090] Example 2

[0091] A preparation method of a full electrolytic cell, the method comprising:

[0092] Preparing a composite material:

[0093] La 0.6 Sr 0.4 Synthesis of LaSrFeO3: First, a total of 5 g of lanthanum nitrate hexahydrate, strontium nitrate, and iron nitrate nonahydrate powders are dissolved in 10 ml of water according to the stoichiometric ratio. After stirring and dissolving, 20 ml of 50% EDTA ammonia aqueous solution is added. After stirring and dissolving, 10 g of citric acid is added. Stir at 80 °C until the solution evaporates to form a gel. After taking out the gel, bake it at 250 °C for 10 hours to form a black powder coke-like powder, and then keep it at 900 °C for 5 h to form La1-xSrxFeO3 powder, grind it for 10 minutes and store it after drying.

[0094] La 0.6 Sr 0.4 LaSrFeO3 - 5% Mo 0.1 W 0.9 O 3-d Synthesis: Dissolve a total of 0.5 g of ammonium metatungstate and 0.044 g of ammonium molybdate in 10 ml of water. After stirring and dissolving, add 10 ml of 50% EDTA ammonia aqueous solution. After stirring and dissolving, add 1 g of citric acid. Add 10 g of La 0.6 Sr 0.4 FeO3 powder into the solution to form a suspension. Stir at 80 °C until the solution evaporates to form a gel. After taking out the gel, bake it at 250 °C for 10 hours to form a black powder coke-like powder, and then keep it at 500 °C for 5 h to form La 0.6 Sr 0.4 LaSrFeO3 - 5% Mo 0.1 W 0.9 O 3-d powder, grind it for 10 minutes and store it after drying.

[0095] Preparing a full electrolytic cell from the above composite material:

[0096] Mix 2 ml of a 6% ethyl cellulose terpineol solution with 2 g of La 0.6 Sr 0.4 LaSrFeO3 - 5% Mo 0.1 W 0.9 O 3-d powder and ball mill for 5 h to obtain an electrode paste. Screen-print the electrode paste on the electrolyte surface of the half electrolytic cell and repeat the printing three times. Put the obtained half cell into a constant temperature heating at 950 °C for 2 h, and after cooling to room temperature, obtain a cell with La 0.6 Sr 0.4 LaSrFeO3 - 5% Mo0.1 W 0.9 O 3-d The all - electrolytic cell of the oxygen electrode layer.

[0097] Example 3

[0098] A preparation method of an all - electrolytic cell, the method comprising:

[0099] Preparing a composite material:

[0100] La 0.6 Sr 0.4 Synthesis of LaSrFeO3: First, a total of 5 g of lanthanum nitrate hexahydrate, strontium nitrate, and iron(III) nitrate nonahydrate powders are dissolved in 10 ml of water according to the stoichiometric ratio. After stirring and dissolving, 20 ml of 50% ammonia solution of EDTA is added. After stirring and dissolving, 10 g of citric acid is added. Stir at 80 °C until the solution evaporates to form a gel. After taking out the gel, it is baked at 250 °C for 10 hours to form a black powder in the form of coke - like powder, and then kept at 900 °C for 5 h to form La1 - xSrxFeO3 powder, which is ground for 10 minutes and stored after drying.

[0101] La 0.6 Sr 0.4 LaSrFeO3 - 5% Mo 0.9 W 0.1 O 3-d Synthesis: 0.081 g of ammonium metatungstate and 0.577 g of ammonium molybdate are dissolved in 10 ml of water. After stirring and dissolving, 10 ml of 50% ammonia solution of EDTA is added. After stirring and dissolving, 1 g of citric acid is added. 10 g of La 0.6 Sr 0.4 FeO3 powder is added to the solution to form a suspension. Stir at 80 °C until the solution evaporates to form a gel. After taking out the gel, it is baked at 250 °C for 10 hours to form a black powder in the form of coke - like powder, and then kept at 500 °C for 5 h to form La 0.6 Sr 0.4 FeO3 - 5% Mo 0.9 W 0.1 O 3-d powder, which is ground for 10 minutes and stored after drying.

[0102] Preparing the all - electrolytic cell with the above - mentioned composite material:

[0103] Mix 2 ml of a 6% ethyl cellulose solution in terpineol with 2 g of La 0.6 Sr 0.4 FeO3 - 5% Mo 0.9 W 0.1 O 3-dThe electrode paste was prepared by ball milling the powder for 5 h. The electrode paste was screen-printed on the surface of the electrolyte of the half electrolytic cell three times repeatedly. The obtained half cell was put into a constant temperature heating at 950 °C for 2 h, and after cooling to room temperature, a full electrolytic cell with a La 0.6 Sr 0.4 FeO3-5% Mo 0.9 W 0.1 O 3-d oxygen electrode layer was obtained.

[0104] Example 4

[0105] A preparation method of a full electrolytic cell, the method comprising:

[0106] Preparing a composite material:

[0107] La 0.6 Sr 0.4 Synthesis of FeO3: First, a total of 5 g of lanthanum nitrate hexahydrate, strontium nitrate, and iron nitrate nonahydrate powders were dissolved in 10 ml of water according to the stoichiometric ratio. After stirring and dissolving, 20 ml of 50% EDTA ammonia aqueous solution was added. After stirring and dissolving, 10 g of citric acid was added. Stir at 80 °C until the solution evaporated to form a gel. After taking out the gel, it was baked at 250 °C for 10 hours to form a black powder coke-like powder, and then kept at 900 °C for 5 h to form La1-xSrxFeO3 powder, which was ground for 10 minutes and stored after drying.

[0108] La 0.6 Sr 0.4 FeO3-1% Mo 0.5 W 0.5 O 3-d Synthesis: 0.066 g of ammonium metatungstate and 0.052 g of ammonium molybdate were dissolved in 2 ml of water. After stirring and dissolving, 2 ml of 50% EDTA ammonia aqueous solution was added. After stirring and dissolving, 1 g of citric acid was added. 10 g of La 0.6 Sr 0.4 FeO3 powder was added to the solution to form a suspension. Stir at 80 °C until the solution evaporated to form a gel. After taking out the gel, it was baked at 250 °C for 10 hours to form a black powder coke-like powder, and then kept at 500 °C for 5 h to form La 0.6 Sr 0.4 FeO3-1% Mo 0.5 W 0.5 O 3-d powder, which was ground for 10 minutes and stored after drying.

[0109] Preparing a full electrolytic cell from the above composite material:

[0110] 2 ml of a 6% ethyl cellulose terpineol solution and 2 g of La 0.6 Sr0.4 FeO3 - 1% Mo 0.5 W 0.5 O 3-d The electrode slurry was prepared by ball - milling the powder for 5 h. The electrode slurry was screen - printed on the surface of the electrolyte of the half - electrolytic cell three times repeatedly. The obtained half - cell was placed in a constant - temperature heating furnace heated to 950 °C for 2 h, and after cooling to room temperature, a full - electrolytic cell with a La 0.6 Sr 0.4 FeO3 - 1% Mo 0.5 W 0.5 O 3-d oxygen electrode layer was obtained.

[0111] Example 5

[0112] A preparation method of a full - electrolytic cell, the method comprising:

[0113] Preparing a composite material:

[0114] La 0.6 Sr 0.4 Synthesis of LaSrFeO3: First, a total of 5 g of lanthanum nitrate hexahydrate, strontium nitrate, and iron(III) nitrate nonahydrate powders were dissolved in 10 ml of water according to the stoichiometric ratio. After stirring and dissolving, 20 ml of 50% EDTA ammonia solution was added. After stirring and dissolving, 10 g of citric acid was added. Stirring was carried out at 80 °C until the solution evaporated to form a gel. After taking out the gel, it was baked at 250 °C for 10 hours to form a black powder in the shape of coke, and then kept at 900 °C for 5 h to form La1 - xSrxFeO3 powder, which was ground for 10 minutes and stored after drying.

[0115] La 0.6 Sr 0.4 FeO3 - 10% Mo 0.5 W 0.5 O 3-d Synthesis: 0.660 g of ammonium metatungstate and 0.522 g of ammonium molybdate were dissolved in 10 ml of water. After stirring and dissolving, 10 ml of 50% EDTA ammonia solution was added. After stirring and dissolving, 1 g of citric acid was added. 10 g of La 0.6 Sr 0.4 FeO3 powder was added to the solution to form a suspension. Stirring was carried out at 80 °C until the solution evaporated to form a gel. After taking out the gel, it was baked at 250 °C for 10 hours to form a black powder in the shape of coke, and then kept at 500 °C for 5 h to form La 0.6 Sr 0.4 FeO3 - 10% Mo 0.5 W 0.5 O 3-d powder, which was ground for 10 minutes and stored after drying.

[0116] Preparing the full - electrolytic cell with the above - mentioned composite material:

[0117] Mix 2 ml of a 6% ethyl cellulose solution in terpineol with 2 g of La 0.6 Sr 0.4 FeO3 - 10% Mo 0.5 W 0.5 O 3-d powder and ball - mill for 5 h to prepare an electrode paste. Screen - print the electrode paste on the surface of the electrolyte of a half - electrolytic cell three times repeatedly. Place the obtained half - cell in an oven heated to 950 °C and keep it at a constant temperature for 2 h. After cooling to room temperature, a full - electrolytic cell with a La 0.6 Sr 0.4 FeO3 - 10% Mo 0.5 W 0.5 O 3-d oxygen electrode layer is obtained.

[0118] Example 6

[0119] A method for preparing a full - electrolytic cell, the method comprising:

[0120] Prepare a composite material:

[0121] La 0.6 Sr 0.4 Synthesis of FeO3: First, dissolve a total of 5 g of lanthanum nitrate hexahydrate, strontium nitrate, and iron(III) nitrate nonahydrate powders in 10 ml of water according to the stoichiometric ratio. After stirring and dissolving, add 20 ml of a 50% aqueous ammonia solution of EDTA. After stirring and dissolving, add 10 g of citric acid. Stir at 80 °C until the solution evaporates to form a gel. After taking out the gel, bake it at 250 °C for 10 hours to form a black powder in the shape of coke powder, and then keep it at 900 °C for 5 h to form La1 - xSrxFeO3 powder, grind it for 10 minutes and store it after drying.

[0122] La 0.6 Sr 0.4 FeO3 - 20% Mo 0.5 W 0.5 O 3-d Synthesis: Dissolve a total of 1.319 g of ammonium metatungstate and 1.043 g of ammonium molybdate in 20 ml of water. After stirring and dissolving, add 20 ml of a 50% aqueous ammonia solution of EDTA. After stirring and dissolving, add 1 g of citric acid. Add 10 g of La 0.6 Sr 0.4 FeO3 powder to the solution to form a suspension. Stir at 80 °C until the solution evaporates to form a gel. After taking out the gel, bake it at 250 °C for 10 hours to form a black powder in the shape of coke powder, and then keep it at 500 °C for 5 h to form La 0.6 Sr 0.4 FeO3 - 20% Mo 0.5 W 0.5 O3-d The powder was ground for 10 minutes and stored dry.

[0123] Prepare a full electrolytic cell with the above composite material:

[0124] Mix 2 ml of a 6% ethyl cellulose solution in terpineol with 2 g of La 0.6 Sr 0.4 FeO3 - 20% Mo 0.5 W 0.5 O 3-d The powder was ball-milled for 5 h to prepare an electrode paste. The electrode paste was screen-printed on the electrolyte surface of the half electrolytic cell three times repeatedly. The obtained half cell was placed in an oven heated to 950 °C and kept at a constant temperature for 2 h, and then cooled to room temperature to obtain a full electrolytic cell with a La 0.6 Sr 0.4 FeO3 - 20% Mo 0.5 W 0.5 O 3-d oxygen electrode layer.

[0125] Example 7

[0126] A method for preparing a full electrolytic cell, the method comprising:

[0127] Prepare a composite material:

[0128] La 0.6 Sr 0.4 Synthesis of FeO3: First, a total of 5 g of lanthanum nitrate hexahydrate, strontium nitrate, and iron(III) nitrate nonahydrate powders were dissolved in 10 ml of water according to the stoichiometric ratio. After stirring and dissolving, 20 ml of a 50% aqueous ammonia solution of EDTA was added. After stirring and dissolving, 10 g of citric acid was added. Stir at 80 °C until the solution evaporated to form a gel. After taking out the gel, it was baked at 250 °C for 10 hours to form a black powder in the form of coke powder, and then kept at 900 °C for 5 h to form La1-xSrxFeO3 powder, which was ground for 10 minutes and stored dry.

[0129] La 0.6 Sr 0.4 FeO3 - 30% Mo 0.5 W 0.5 O 3-d Synthesis: Dissolve a total of 1.979 g of ammonium metatungstate and 1.565 g of ammonium molybdate in 30 ml of water. After stirring and dissolving, 30 ml of a 50% aqueous ammonia solution of EDTA was added. After stirring and dissolving, 3 g of citric acid was added. Add 10 g of La 0.6 Sr 0.4 FeO3 powder to the solution to form a suspension. Stir at 80 °C until the solution evaporated to form a gel. After taking out the gel, it was baked at 250 °C for 10 hours to form a black powder in the form of coke powder, and then kept at 500 °C for 5 h to form La0.6 Sr 0.4 SrFeO₃ - 30% Mo 0.5 W 0.5 O 3-d Powder, ground for 10 minutes and stored dry.

[0130] Prepare a full electrolytic cell with the above composite material:

[0131] Mix 2 ml of a 6% ethyl cellulose solution in terpineol with 2 g of La 0.6 Sr 0.4 SrFeO₃ - 30% Mo 0.5 W 0.5 O 3-d Powder was ball - milled for 5 h to obtain an electrode paste. The electrode paste was screen - printed on the electrolyte surface of the half - electrolytic cell three times repeatedly. The obtained half - cell was placed in an oven heated to 950 °C and kept at a constant temperature for 2 h, and then cooled to room temperature to obtain a full electrolytic cell with a La 0.6 Sr 0.4 SrFeO₃ - 30% Mo 0.5 W 0.5 O 3-d oxygen electrode layer.

[0132] Comparative Example 1

[0133] A method for preparing a full electrolytic cell, the method comprising:

[0134] La 0.6 Sr 0.4 Synthesis of LaSrFeO₃: First, a total of 5 g of lanthanum nitrate hexahydrate, strontium nitrate, and iron(III) nitrate nonahydrate powders were dissolved in 10 ml of water according to the stoichiometric ratio. After stirring and dissolving, 20 ml of a 50% EDTA ammonia solution was added. After stirring and dissolving, 10 g of citric acid was added. Stir at 80 °C until the solution evaporated to form a gel. After taking out the gel, it was baked at 250 °C for 10 hours to form a black powder, a coke - like powder, and then kept at 900 °C for 5 h to form La 0.6 Sr 0.4 SrFeO₃ powder, ground for 10 minutes and stored dry.

[0135] La 0.6 Sr 0.4 Preparation of the LaSrFeO₃ electrode layer: Mix 2 ml of a 6% ethyl cellulose solution in terpineol with 2 g of La 0.6 Sr 0.4 SrFeO₃ powder was ball - milled for 5 h to obtain an electrode paste. The electrode paste was screen - printed on the electrolyte surface of the half - electrolytic cell three times repeatedly. The obtained half - cell was placed in an oven heated to 950 °C and kept at a constant temperature for 2 h, and then cooled to room temperature to obtain a full electrolytic cell with a La 0.6 Sr 0.4 SrFeO₃ oxygen electrode layer.

[0136] Comparative Example 2

[0137] A preparation method of a full electrolytic cell, the method comprising:

[0138] Mo 0.5 W 0.5 O 3-d Synthesis: Dissolve a total of 6.597 g of ammonium metatungstate and 5.216 g of ammonium molybdate in 10 ml of water. After stirring and dissolving, add 10 ml of an aqueous ammonia solution of 50% EDTA. After stirring and dissolving, add 10 g of citric acid. Stir at 80 °C until the solution evaporates to form a gel. After taking out the gel, bake it at 250 °C for 10 hours to form a black powder coke-like powder, and then keep it at 500 °C for 5 h to form Mo 0.5 W 0.5 O 3-d powder, grind for 10 minutes and store it dry.

[0139] Mo 0.5 W 0.5 O 3-d Preparation of the electrode layer: Ball-mill 2 ml of a 6% ethyl cellulose solution in terpineol with 2 g of Mo 0.5 W 0.5 O 3-d powder for 5 h to obtain an electrode paste. Screen-print the electrode paste on the electrolyte surface of the half electrolytic cell and repeat the printing three times. The obtained half cell is placed in a constant temperature heating at 950 °C for 2 h, and after cooling to room temperature, a full electrolytic cell with a Mo 0.5 W 0.5 O 3-d oxygen electrode layer is obtained.

[0140] The composite materials provided in Examples 1 to 7 were analyzed. Since the results are similar, only the composite material provided in Example 1 will be taken as an example for illustration below.

[0141] As Figures 2 to 4 shown, Figure 2 is the scanning electron microscope image of the composite material provided in Example 1 of this application, Figure 3 is the transmission electron microscope image of Example 1 of this application, and Figure 4 is the powder X-ray diffraction pattern of the composite materials provided in Example 1 and Comparative Examples 1 and 2 of this application. From the scanning electron microscope image, it can be seen that Mo 0.5 W 0.5 O 3-d is more uniformly mixed with La 0.6 Sr 0.4 FeO3. The particle size of Mo 0.5 W 0.5 O 3-d is about 0.05 - 0.2 μm, and La 0.6 Sr0.4 The particle size of FeO3 is about 0.2 - 0.5 μm. For Mo in Example 1 0.5 W 0.5 O 3-d The particles were detected by transmission electron microscopy and elemental analysis ( Figure 3 ). It can be seen that the Mo and W elements are uniformly distributed in the electrode particles. From the powder X-ray diffraction pattern, it can be seen that there are corresponding diffraction peaks of Mo 0.5 W 0.5 O 3-d and La 0.6 Sr 0.4 FeO3, and no additional phases appear.

[0142] The electrolytic performance of the full electrolytic cells provided in Example 1 and Comparative Examples 1 to 2 was tested. The test process included: heating the cell to 750 °C, introducing steam (H2O / H2 = 1:4) on the fuel electrode side and air on the oxygen electrode side for high-temperature electrolytic water testing. The results are as Figure 5 shown, Figure 5 This is the electrolytic performance diagram of the composite materials provided in Example 1, Comparative Example 1, and Comparative Example 2 of the present application. From the figure, it can be obtained that La 0.6 Sr 0.4 FeO3 - 5% Mo 0.5 W 0.5 O 3-d (Example 1) The electrolytic voltage at a current density of 1 A / cm 2 is only 1.36 V, which has better electrolytic performance compared to pure La 0.6 Sr 0.4 FeO3 (1.61 V; Comparative Example 1) and Mo 0.5 W 0.5 O 3-d (2.34 V; Comparative Example 2).

[0143] The various embodiments of the present application may exist in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity and should not be construed as a rigid limitation on the scope of the present application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single values within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Additionally, whenever a numerical range is indicated herein, it means including any cited number (fraction or integer) within the indicated range.

[0144] In this application, unless otherwise specified, the orientation terms such as "upper" and "lower" specifically refer to the drawing directions in the attached drawings. Additionally, in the description of this application's specification, terms such as "include" and "comprise" mean "include but not limited to". In this text, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. In this text, "and / or" describes the association relationship of associated objects and indicates that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, or B exists alone. Here, A and B can be singular or plural. In this text, "at least one" means one or more, and "a plurality" means two or more. "At least one kind", "at least one of the following items (pieces)" or similar expressions refer to any combination of these items, including any combination of single items (pieces) or plural items (pieces). For example, "at least one of a, b, or c", or, "at least one of a, b, and c" can both mean: a, b, c, a - b (i.e., a and b), a - c, b - c, or a - b - c, where a, b, and c can be single or multiple respectively.

[0145] The above are only specific implementation manners of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application will not be limited to these embodiments shown herein, but rather will conform to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. A composite material, characterized in that, The composite material includes a composite of a La-based perovskite material and an oxide of a Group VI B element.

2. The composite material according to claim 1, characterized in that, The La-based perovskite material includes La 0.6 Sr 0.4 FeO3.

3. The composite material according to claim 1, characterized in that, The oxides of Group VIB elements include Mo y W 1- y O 3-d , where y is 0.1 to 0.9 and d is 0 to 0.

05.

4. The composite material according to claim 3, characterized in that, The oxides of Group VIB elements include Mo y W 1- y O 3-d , where y is 0.3 to 0.7 and d is 0 to 0.

05.

5. The composite material according to claim 4, wherein The oxides of Group VIB elements include Mo y W 1- y O 3-d , where y is 0.4 to 0.6 and d is 0 to 0.

05.

6. The composite material according to claim 1, wherein The mass ratio of the oxide of the Group VI B element to the La-based perovskite material is 0.01 to 0.

3.

7. The composite material according to claim 6, characterized in that, The mass ratio of the oxide of the Group VI B element to the La-based perovskite material is 0.02 to 0.

1.

8. The composite material according to claim 7, characterized in that, The mass ratio of the oxide of the Group VI B element to the La-based perovskite material is 0.04 to 0.

06.

9. A method for preparing a composite material, characterized in that, The method includes: Obtaining a La-based perovskite material; Composite the La-based perovskite material and the oxide of the Group VI B element to obtain a composite material.

10. The method for preparing the composite material according to claim 9, characterized in that, The obtaining of the La-based perovskite material includes: Dissolve lanthanum nitrate hexahydrate, strontium nitrate and iron(III) nitrate nonahydrate in a solvent to obtain a first mixed solution; Mix the first mixed solution, an aqueous ammonia solution of EDTA and citric acid, and then evaporate to obtain a first gel; Perform a first baking on the first gel, and then perform a first heat preservation treatment to obtain the La-based perovskite material La 0.6 Sr 0.4 FeO3.

11. The preparation method of the composite material according to claim 10, characterized in that, The temperature of the first baking is 200 to 300 °C; The time of the first baking is 9 to 11 hours.

12. The method for preparing the composite material according to claim 11, wherein The temperature of the first baking is 230 to 270 °C; The time of the first baking is 9.5 to 10.5 hours.

13. The preparation method of the composite material according to claim 10, characterized in that, The temperature of the first heat preservation treatment is 800 to 1000 °C; The time of the first heat preservation treatment is 4 to 6 hours.

14. The method for preparing the composite material according to claim 13, wherein, The temperature of the first heat preservation treatment is 850 to 950 °C; The time of the first heat preservation treatment is 4.5 to 5.5 hours.

15. The method for preparing the composite material according to claim 9, wherein The composite of the La-based perovskite material and the oxide of the Group VI B element to obtain a composite material includes: Dissolve ammonium metatungstate and ammonium molybdate in a solvent to obtain a second mixed solution; Mix the second mixed solution, an aqueous ammonia solution of EDTA and citric acid, then add the La-based perovskite material and evaporate to obtain a second gel; Perform a second baking on the second gel, and then perform a second heat preservation treatment to obtain a composite material.

16. The method for preparing the composite material according to claim 15, wherein The temperature of the second baking is 200 to 300 °C; The time of the second baking is 9 to 11 hours.

17. The method for preparing the composite material according to claim 16, wherein The temperature of the second baking is 230 to 270 °C; The time of the second baking is 9.5 to 10.5 hours.

18. The method for preparing the composite material according to claim 15, wherein, The temperature of the second heat preservation treatment is 400 to 600 °C; The time of the second heat preservation treatment is 4 to 6 hours.

19. The method for preparing the composite material according to claim 18, characterized in that, The temperature of the second heat preservation treatment is 450 to 550 °C; The time of the second heat preservation treatment is 4.5 to 5.5 hours.

20. Application of a composite material, characterized in that, The composite material includes the composite material described in any one of claims 1 to 8 or the composite material prepared by the method described in any one of claims 9 to 19, and the application includes using the composite material for electrolytic hydrogen production.

Images