All-solid-state electrolytic cell electrolysis catalyst materials, preparation methods and applications

Abstract

This invention discloses an all-solid-state electrolytic cell catalytic material, its preparation method, and its application. The electrolytic catalytic material is expressed as SFM@M-C, where SFM is Sr2Fe. 1.5 Mo 0.5 O 6‑δ M is one or both of Ni and Co, or a combination of one of Ni and Co with any of Fe and Cu, and C is rare earth-doped SDC. In the electrolytic catalytic material of this invention, metal M has high catalytic performance and can selectively adsorb and activate small molecules such as CO2 and H2O. C, as an oxygen ion conductor, can provide an oxygen ion transport channel and effectively promote oxygen ion transport. By utilizing the strong interaction between M and C, the stability of metal M at high temperatures can be enhanced. Introducing this electrolytic catalytic material into the electrolytic cell effectively improves the co-electrolysis performance and enables the regulation of syngas composition.

Description

Technical Field

[0001] This invention belongs to the field of solid oxide electrolysis cell technology, specifically relating to an all-solid-state electrolysis cell electrolysis catalytic material, its preparation method, and its application. Background Technology

[0002] Solid oxide electrolyzers (SOECs) can utilize renewable energy sources such as wind and solar power to efficiently electrolyze H2O and CO2 to produce H2 and CO syngas. CO2 electrolysis and H2O / CO2 co-electrolysis technologies are of great significance for future energy utilization systems, as they can not only solve the problem of renewable energy storage, but also the problem of greenhouse gas reuse.

[0003] As an all-solid-state electrolyzer, SOEC possesses advantages such as high conversion efficiency and low electrolysis energy consumption, demonstrating promising prospects for large-scale application. In recent years, co-electrolysis technology based on SOEC has also seen rapid development, particularly the co-electrolysis of H2O and CO2. This technology effectively produces CO, H2, or hydrocarbon fuels using renewable energy electricity, achieving electro-gas conversion. More importantly, by using different ratios of H2 and CO, other high-value-added products can be obtained through the Fischer-Tropsch process.

[0004] Currently, SOEC co-electrolysis still faces challenges in syngas control. The co-conversion reaction of water and carbon dioxide is complex, involving not only individual electrochemical reactions but also a reverse water-gas reaction. Furthermore, at operating temperatures, this reverse water-gas reaction significantly impacts the composition control of the syngas. Traditional co-electrolysis offers limited control over the syngas ratio. This instability and unreliability prevents it from providing the standard feedstock gas required for downstream chemical synthesis, directly leading to a severe disconnect from mature chemical industry chains and hindering efficient and stable system coupling. Summary of the Invention

[0005] The purpose of this invention is to provide an all-solid-state electrolytic cell catalytic material, its preparation method, and its application, so as to solve the problem of difficulty in controlling the syngas in SOEC co-electrolysis.

[0006] This invention is achieved through the following technical solution: An all-solid-state electrolytic cell catalytic material, wherein the catalytic material is expressed as SFM@MC; where SFM is Sr2Fe. 1.5 Mo 0.5 O 6-δ M is one or two of Ni and Co, or a combination of one of Ni and Co with any of Fe, Cu, Zn, and Ru, and C is rare earth doped SDC, GDC, or CeO2.

[0007] In some embodiments of the present invention, the SDC is Sm 0.2 Ce 0.8 O2, the GDC is Gd 0.1 Ce 0.9 O2.

[0008] In some embodiments of the present invention, the mass ratio of C to M is 1:10 to 10:1, and the total mass of C and M is 5 to 6 wt.% of SFM.

[0009] On the other hand, the present invention also provides a method for preparing an all-solid-state electrolytic cell catalytic material, comprising the following steps: S01. Prepare precursor powder for SFM. Grind and sieve the precursor powder and then sinter it. S02. Dissolve salt M and the metal salt used to prepare C in deionized water to prepare a metal salt solution; S03. Add the sintered precursor powder from step S01 to the metal salt solution, stir at room temperature, and then freeze dry. S04. The powder obtained by freeze-drying in step S03 is sintered to obtain SFM@MC powder.

[0010] In some embodiments of the present invention, the step of preparing the precursor powder of SFM in step S01 includes: S011. According to the stoichiometric ratio of SFM material, Sr salt, Fe salt and Mo salt are dissolved in deionized water to prepare SFM solution; S012. Add glycine to the SFM solution, stir until the glycine is completely dissolved, and then freeze-dry to obtain the precursor powder of SFM.

[0011] In some embodiments of the present invention, in step S01, the ground precursor powder is passed through a 200-mesh sieve and then sintered at 300-500°C for 5-10 hours.

[0012] In some embodiments of the present invention, in step S04, the powder obtained by freeze drying is subjected to high-temperature sintering at 700-1000°C for 2-10 hours.

[0013] On the other hand, the present invention also provides an all-solid-state electrolytic cell catalytic material, and the application of the all-solid-state electrolytic cell catalytic material prepared by the all-solid-state electrolytic cell catalytic material preparation method in an all-solid-state electrolytic cell.

[0014] In some embodiments of the present invention, SFM@MC slurry is prepared using SFM@MC powder, pore-forming agent, and organic adhesive; the SFM@MC slurry is coated onto the surface of an all-solid-state electrolytic cell and then sintered to form an SFM@MC catalyst layer on the surface of the all-solid-state electrolytic cell.

[0015] In some embodiments of the present invention, the pore-forming agent is one or more of activated carbon, graphite, corn starch or PMMA; and / or, the organic adhesive is composed of ethyl cellulose and terpineol in a mass ratio of (1-10):(90-99).

[0016] Compared with the prior art, the present invention has the following advantages and beneficial effects: In the electrolytic catalytic material of the present invention, metal M has high catalytic performance and can selectively adsorb and activate small molecules such as CO2 and H2O. C, as an oxygen ion conductor, can provide oxygen ion transport channels and effectively promote oxygen ion transport. By utilizing the strong interaction between M and C, the stability of metal M at high temperatures can be enhanced. Introducing this electrolytic catalytic material into the electrolytic cell effectively improves the co-electrolysis performance and enables the regulation of syngas composition.

[0017] This invention employs chemical impregnation and freeze-drying methods to prepare highly dispersed SFM catalytic material powders coated with active metals and oxygen ion conductor oxides. The freeze-drying method ensures the particle size of the prepared nanoparticles, resulting in a powder material with a high specific surface area, which further promotes the dispersion of M and C, thus exhibiting high catalytic activity. The synergistic effect of the active metal and the high-ion conductor oxide further enhances the ability to regulate the composition of syngas from the co-electrolysis of CO2 and H2O. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 The images show the XRD patterns of the catalytic materials prepared in Comparative Example 3 and Example 4 of this invention.

[0020] Figure 2 The graph shows a comparison of the gas production performance of Embodiments 1 and 4, and Comparative Examples 3 and 1 at 800°C during co-electrolysis. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0022] This invention addresses the problems of poor co-electrolysis performance and low CO selectivity by proposing a highly active, highly dispersed, and highly CO-selective core-shell catalytic material to achieve control over the composition of syngas produced through co-electrolysis. The MC-coated SFM syngas control catalytic material is prepared using impregnation and freeze-drying methods. Metal M provides high catalytic activity sites, while C acts as an oxygen ion conductor to provide oxygen ion transport channels. Simultaneously, the dispersion of metal M is stabilized at high temperatures, maintaining its small nanoscale size. This solves the problem of cathode stability in solid oxide electrolyzers during high-temperature operation, improves the co-electrolysis performance of the electrolyzer, and enables control over the composition of syngas.

[0023] In some embodiments of the present invention, the electrolytic catalyst material for the all-solid-state electrolytic cell is expressed as SFM@MC; wherein, SFM is Sr2Fe 1.5 Mo 0.5 O 6-δ M can be one or two of Ni and Co, or a combination of Ni, Co and any of Fe, Cu, Zn, and Ru, and C can be rare earth doped SDC, GDC, or CeO2. For example, M can be Ni, Co, a combination of Ni and Co, a combination of Ni and Fe, a combination of Ni and Cu, a combination of Ni and Zn, a combination of Ni and Ru, a combination of Co and Fe, a combination of Co and Cu, a combination of Co and Zn, or a combination of Co and Ru.

[0024] SDC is Sm 0.2 Ce 0.8 O2, GDC is Gd 0.1 Ce 0.9 O2.

[0025] The mass ratio of C to M is 1:10 to 10:1, and the total mass of C and M is 5 to 6 wt.% of SFM.

[0026] When M is a combination of Ni and Co with two metals, Fe, Cu, Zn, and Ru, the molar ratio of the two metals is 1:1.

[0027] On the other hand, some embodiments of the present invention relate to a method for preparing an all-solid-state electrolytic cell catalytic material, comprising the following steps: S1. SFM powder is prepared using the glycine-citrate method. Sr salt, Fe salt, and Mo salt are dissolved in deionized water according to the stoichiometric ratio of SFM to prepare a 1 mol / L solution A. Sr salt and Fe salt can be nitrates or chlorides, and Mo salt can be ammonium molybdate.

[0028] S2. Add glycine to solution A and stir at 300 r / min. After the glycine is completely dissolved, freeze-dry the mixture to obtain SFM nano precursor powder. Grind the precursor powder through a 200-mesh sieve and sinter it at different temperatures.

[0029] In this step, the molar ratio of glycine to the total metal ions in SFM is (1-5):1.

[0030] The sintering temperature is 300-500℃, and the sintering time is 5-10 hours. For example, the sintering temperature is 500℃ and the sintering time is 5 hours.

[0031] S3. Dissolve salt M and the metal salt used to prepare C in deionized water to prepare a solution with a concentration of 0.1 mol / L-0.5 mol / L.

[0032] M salt, the metal salt used to prepare C can be a nitrate or a chloride salt, the concentration of the prepared solution can be 0.2 mol / L, and the mass ratio of C to M is 1:10 to 10:1, and the total mass of C and M is 5 to 6 wt. of SFM.

[0033] S4. Add the powder obtained in step S2 to the solution in S3, stir at 300 r / min for 5-12 h at room temperature, and then freeze dry.

[0034] S5. The freeze-dried powder is sintered at 700-1000℃ for 2-10 hours to obtain SFM@MC catalyst powder.

[0035] On the other hand, the present invention also relates to an all-solid-state electrolytic cell electrolysis catalytic material as described above, and the application of the all-solid-state electrolytic cell electrolysis catalytic material prepared by the above preparation method in an all-solid-state electrolytic cell.

[0036] Taking existing commercial electrolytic cells as an example, SFM@MC powder, pore-forming agent, and organic adhesive are mixed and ground in a mass ratio of 1:1:0.5 to obtain SFM@MC slurry; The SFM@MC slurry was coated onto the Ni-3YSZ surface of a commercial Ni-3YSZ / Ni-8YSZ / YSZ / SDC / LSCF-SDC electrolytic cell and sintered at 900-1100℃ for 2-10 hours to form an SFM@MC catalytic layer on the Ni-3YSZ surface.

[0037] The all-solid-state electrolyzer prepared at this time consists of a 6-layer structure, which is represented as SFM@MC / Ni-3YSZ / Ni-8YSZ / YSZ / SDC / LSCF-SDC; wherein, Ni-3YSZ is the support, Ni-8YSZ is the active layer, YSZ is the electrolyte, SDC is the buffer layer, LSCF-SDC is the oxygen electrode, and SFM@MC is the catalyst layer used for the control of syngas composition.

[0038] The pore-forming agent is one or more of activated carbon, graphite, corn starch, or PMMA, for example, PMMA can be used. The organic adhesive is composed of ethyl cellulose and terpineol in a mass ratio of (1-10):(99-90), for example, the mass ratio of ethyl cellulose to terpineol is 4:96.

[0039] The all-solid-state electrolytic cell with a catalyst layer prepared above was sealed on an alumina tube. After heating, CO2 and H2O were introduced into the cathode layer and then an electric current was applied to prepare syngas.

[0040] The synthesis gas was prepared at a temperature of 650-850℃, with a CO2 to H2O volume ratio of (0.1-9):1, and 10% H2 was used as a protective gas; the current density was 0.1-2 A·cm³. -2 .

[0041] The present invention will now be described in detail with reference to specific embodiments and comparative examples.

[0042] Example 1 Prepare an all-solid-state electrolytic cell according to the following steps: S1, to synthesize 1 mol Sr2Fe 1.5 Mo 0.5 O 6-δ For example, weigh 2 mol of strontium nitrate, 1.5 mol of ferric nitrate and 0.125 mol of ammonium molybdate, add them to deionized water and stir to prepare a 1 mol / L solution.

[0043] S2. Weigh 5 mol of glycine and add it to the solution in step S1. Stir at 300 r / min until the glycine is completely dissolved. Place the dissolved mixture into a freeze dryer for freeze drying. After water sublimation, the precursor powder of SFM is obtained. Grind the precursor powder, pass it through a 200-mesh sieve, and sinter it at 500℃ for 5 h.

[0044] S3. Based on the total mass of Ni and SDC accounting for 6 wt.% of the mass of SFM and the mass ratio of Ni to SDC being 5:1, weigh out M salt (nickel nitrate), samarium nitrate, and cerium nitrate, dissolve them in deionized water, and prepare a transparent and clear solution with a concentration of 0.2 mol / L.

[0045] S4. Add the powder obtained in step S2 to the solution in S3, stir at 300 r / min for 10 h at room temperature to ensure that the salt solution fully wets the SFM powder, and freeze dry.

[0046] S5. The powder obtained after freeze-drying in step S4 is sintered at 700℃ for 2 hours to obtain SFM@M-SDC powder.

[0047] S6. Mix SFM@M-SDC powder, PMMA, and a terpineol solution containing 4 wt.% ethyl cellulose to obtain SFM@M-SDC slurry. The ratio of SFM@M-SDC powder:PMMA:terpineol solution is 1:1:0.5 (mass ratio).

[0048] S7. The SFM@M-SDC slurry is coated on the Ni-3YSZ surface of a commercial Ni-3YSZ / Ni-8YSZ / YSZ / SDC / LSCF-SDC electrolytic cell, and then sintered at 1000℃ for 2h to prepare an all-solid-state electrolytic cell with an SFM@M-SDC catalyst layer.

[0049] S8. Seal the all-solid-state electrolytic cell obtained in step S7 onto an alumina tube. After heating, introduce 45% CO2-45% H2O-10% H2 into the cathode layer, and then apply 0.1-2 A·cm. -2 The current was measured, and the components of H2 and CO in the exhaust gas were analyzed by gas chromatography and the ratio was calculated.

[0050] Example 2 The steps in Example 2 are the same as those in Example 1, except that in step S3, the M salt is Ni(NO3)2·6H2O, and the mass ratio of SDC oxide to M salt is 1:1.

[0051] Example 3 The steps in Example 3 are the same as those in Example 1, except that in step S3, the M salt is Ni(NO3)2·6H2O, and the mass ratio of SDC oxide to M salt is 1:5.

[0052] Example 4 The steps in Example 4 are the same as those in Example 1, except that in step S3, the M salt is Ni(NO3)2·6H2O and Cu(NO3)2·6H2O, the molar ratio of Ni to Cu is 1:1, and the mass ratio of SDC oxide to M salt is 1:1.

[0053] Example 5 The steps in Example 5 are the same as those in Example 1, except that in step S3, the M salt is Ni(NO3)2·6H2O and Co(NO3)2·6H2O, the molar ratio of Ni to Co is 1:1, and the mass ratio of SDC oxide to M salt is 1:1.

[0054] Example 6 The steps in Example 6 are the same as those in Example 1, except that in step S3, the M salt is Ni(NO3)2·6H2O and Fe(NO3)2·6H2O, the molar ratio of Ni to Fe is 1:1, and the mass ratio of SDC oxide to M salt is 1:1.

[0055] Example 7 The steps in Example 7 are the same as those in Example 1, except that in step S3, the M salt is Co(NO3)2·6H2O, and the mass ratio of SDC oxide to M salt is 1:1.

[0056] Comparative Example 1 The steps of Comparative Example 1 and Example 1 are the same, except that only cerium nitrate is used in step S3, the catalyst layer component is SFM@CeO2, and the sintering temperature of step S7 is 1100℃.

[0057] The electrolytic cell structure in Comparative Example 1 is SFM / CeO2 / Ni-3YSZ / Ni-8YSZ / YSZ / SDC / LSCF-SDC.

[0058] Comparative Example 2 Comparative Example 1 and Example 1 follow the same steps, except that in step S3, samarium nitrate and cerium nitrate are used, the catalyst layer composition is SFM@SDC, and the sintering temperature in step S7 is 1100℃.

[0059] The electrolytic cell structure in Comparative Example 1 is SFM / SDC / Ni-3YSZ / Ni-8YSZ / YSZ / SDC / LSCF-SDC.

[0060] Comparative Example 3 The steps in Comparative Example 3 are the same as those in Example 1, except that in step S3, the M salt is Cu(NO3)2·6H2O, and the mass ratio of SDC oxide to M salt is 1:1.

[0061] Table 1 shows the performance comparison of the electrolyzers in the examples and the comparative examples, as well as the detection data of the components of the prepared syngas.

[0062] Table 1

[0063]

[0064] As can be seen from Table 1, in Comparative Examples 1-2, no active metal catalyst was introduced, and the polarization resistance of the electrolytic cells was relatively high, all around 1 Ω·cm. 2 The corresponding co-electrolysis performance also shows a relatively low current density at 1.3V.

[0065] In Examples 1-7, the polarization resistance of the electrolytic cell was significantly reduced and the current density at 1.3V was increased by introducing an active metal catalyst, indicating that the introduction of a specific active metal catalyst in the examples improved the co-electrolysis performance of the electrolytic cell.

[0066] When Cu metal catalyst was introduced alone in Comparative Example 3, the polarization resistance and co-electrolysis performance of the electrolytic cell were significantly worse than those in Examples 1-7, indicating that the type and composition of the metal catalyst have a significant impact on the performance of the electrolytic cell.

[0067] Meanwhile, the comparison shows that the introduction of an active metal catalyst in the examples can greatly increase the proportion of H2 in the co-electrolysis synthesis gas, while the CO content in the comparative examples is increased.

[0068] from Figure 1 As can be seen, in addition to the main phase of SFM, there are also NiO and SDC phases. The SDC content in Example 4 is higher than the peak value of SDC in Comparative Example 3. SDC@PDF#750158 represents the diffraction peak of SDC, CuO@PDF#80-0076 represents the CuO peak, and Cu@PDF#901-3023 represents the diffraction peak of Cu.

[0069] from Figure 2 As can be seen, the technical solution of the present invention can achieve continuous control of the syngas ratio over a large range, while the control range of the syngas ratio is smaller when using the solutions of Comparative Example 1 and Comparative Example 3.

[0070] Certain terms are used in the specification and claims to refer to specific components. Those skilled in the art will understand that hardware manufacturers may use different names to refer to the same component. This specification and claims do not distinguish components based on differences in name, but rather on differences in function. The terms "comprising" and "including" used throughout the specification and claims are open-ended and should be interpreted as "comprising / including but not limited to". "Approximately" means that within an acceptable margin of error, those skilled in the art can solve the technical problem and substantially achieve the technical effect within a certain margin of error. The following descriptions in the specification are preferred embodiments for carrying out this application; however, these descriptions are for the purpose of illustrating the general principles of this application and are not intended to limit the scope of this application. The scope of protection of this application shall be determined by the appended claims.

[0071] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a product or system comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a product or system. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the product or system that includes said element.

[0072] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0073] The foregoing description illustrates and describes several preferred embodiments of this application. However, as previously stated, it should be understood that this application is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the application concept described herein through the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of this application should be within the protection scope of the appended claims.

Claims

1. An electrolytic catalyst material for an all-solid-state electrolytic cell, characterized in that, The electrolytic catalyst is expressed as SFM@MC; where SFM is Sr2Fe 1.5 Mo 0.5 O 6-δ M is Co, or a combination of Ni and Co, or a combination of one of Ni or Co with any of Fe or Cu; C is Sm. 0.2 Ce 0.8 O2.

2. The all-solid-state electrolytic cell catalytic material according to claim 1, characterized in that, The mass ratio of C to M is 1:5 to 5:1, and the total mass of C and M is 5 to 6 wt.% of SFM.

3. The method for preparing the all-solid-state electrolytic cell catalytic material according to any one of claims 1-2, characterized in that, Includes the following steps: S01. Prepare precursor powder for SFM, grind and sieve the precursor powder and then sinter it. S02. Dissolve salt M and the metal salt used to prepare C in deionized water to prepare a metal salt solution; S03. Add the sintered precursor powder from step S01 to the metal salt solution, stir at room temperature, and then freeze dry. S04. Sinter the powder obtained by freeze-drying in step S03 to obtain SFM@MC powder; The steps in step S01 for preparing the precursor powder of SFM include: S011. According to the stoichiometric ratio of SFM material, Sr salt, Fe salt and Mo salt are dissolved in deionized water to prepare SFM solution; S012. Add glycine to the SFM solution, stir until the glycine is completely dissolved, and then freeze-dry to obtain the precursor powder of SFM.

4. The preparation method according to claim 3, characterized in that, In step S01, the ground precursor powder is passed through a 200-mesh sieve and then sintered at 500°C for 5 hours.

5. The preparation method according to claim 3, characterized in that, In step S04, the powder obtained by freeze drying is sintered at 700°C for 2 hours.

6. The application of the all-solid-state electrolytic cell catalytic material according to any one of claims 1-2 or the all-solid-state electrolytic cell catalytic material prepared by the preparation method according to any one of claims 3-5 in an all-solid-state electrolytic cell.

7. The application of the all-solid-state electrolytic cell catalytic material according to claim 6 in an all-solid-state electrolytic cell, characterized in that, SFM@MC slurry was prepared using SFM@MC powder, pore-forming agent, and organic adhesive. The SFM@MC slurry was coated onto the surface of an all-solid-state electrolytic cell and then sintered to form an SFM@MC catalyst layer on the surface of the all-solid-state electrolytic cell.

8. The application of the all-solid-state electrolytic cell catalytic material according to claim 7 in an all-solid-state electrolytic cell, characterized in that, The pore-forming agent is PMMA; and / or the organic adhesive is composed of ethyl cellulose and terpineol.

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