Electrode material and preparation method and application thereof

Abstract

The invention relates to the technical field of fuel cells, in particular to an electrode material and a preparation method and application thereof. The electrode material is obtained through in-situ reduction by taking a solid-phase mixed precursor as a precursor. Wherein x is more than or equal to 0 and less than or equal to 0.3, y is more than or equal to 0 and less than or equal to 0.3, z is more than or equal to 0 and less than or equal to 0.3, and delta is oxygen vacancy content. The preparation method of the electrode material is simple, convenient, economical and high in repeatability, and the reaction conditions are mild and controllable. When the electrode material is used as a fuel electrode of a solid oxide electrolytic cell and a fuel cell, the electrode material shows excellent electrochemical performance during hydrocarbon fuel electrochemical oxidation power generation and carbon dioxide electrolytic reduction.

Description

Technical Field

[0001] This invention relates to the field of electrode material preparation technology, specifically to an electrode material, its preparation method, and its application. Background Technology

[0002] The overuse of fossil fuels has led to problems such as climate change and global warming, making solid oxide cells (SOCs) a key, efficient, and clean energy conversion technology of great interest. SOCs mainly include solid oxide fuel cells (SOFCs) for power generation and solid oxide electrolyzers (SOECs) that electrochemically convert CO2 or H2O into CO or H2. SOECs, in particular, have advantages such as low overpotential and high energy efficiency, and can be coupled with intermittent renewable energy sources such as wind and solar power, as well as nuclear power and industrial waste heat systems, and are considered an effective way to achieve CO2 resource utilization and carbon neutrality goals. However, efficient and stable cathode materials for high-temperature CO2 electroreduction reactions (CO2RR) remain a key bottleneck restricting the development of this technology.

[0003] Perovskite oxides (ABO3) are promising candidates for high-temperature electrochemical applications due to their mixed ionic-electron conductivity, resistance to carbon deposition, and thermal / redox stability. However, their CO2 reduction reaction (CO2RR) kinetics are inferior to those of commercially available nickel-based ceramic cathodes. Most unmodified perovskite oxide cathodes exhibit poor catalytic activity, and prolonged exposure to pure CO2 at high temperatures leads to crystal structure instability and performance degradation. For example, the commonly used Sr2Fe... 1.5 Mo 0.5 O 6−δ Taking (SFM) perovskite as an example, its lattice oxygen intrinsic reactivity is low, which limits CO2 adsorption activation, oxygen vacancy formation, and bulk O. 2- Ion migration leads to slow CO2RR kinetics.

[0004] Currently, modification strategies such as morphology control, surface engineering, and chemical doping have been developed to improve the CO2 electrolysis catalytic performance of perovskite oxides. While impregnation is effective, its low preparation temperature easily leads to high-temperature coarsening of the impregnated nanoparticles. Another efficient method is to dope the A-site and / or B-site of perovskite oxides with low-valence metal ions to generate oxygen vacancies and enhance its activity. Furthermore, the introduction of catalyst metal dopants can precipitate into nanoparticles under specific conditions, thereby improving catalytic activity; for example, SFM perovskite doped with elements such as Bi, Ni, Co, Ir, and Cu shows a significant improvement in CO2 electrolysis performance. The morphology and microstructure of in-situ precipitated nanoparticles affect catalytic activity, and constructing core-shell structured nanoparticles can effectively improve performance; for example, La... 0.4 Sr 0.6 Co7W6@WO dispersed on TiO3 surfacex Nanoparticles and precipitated nanoparticles with a Co-Fe@CoFeO4 core-shell structure on the surface of LaBaMn2O5 can both expand the three-phase boundary, enhance catalytic activity, and improve carbon deposition resistance. This is mainly due to the synergistic effect of the core-shell structure and oxygen vacancy active sites. Furthermore, the synergistic effect of perovskite oxides and oxygen ion conductors (such as cerium oxide doped with perovskite) can improve CO2RR performance. However, the preparation of this composite cathode using mechanical grinding or impregnation methods suffers from cumbersome processes and uneven distribution. On the other hand, no reported materials or preparation methods can simultaneously achieve the above advantages. Therefore, there is an urgent need to develop a novel solid oxide battery electrode material to solve these problems. Summary of the Invention

[0005] The purpose of this invention is to provide an electrode material and its preparation method, so as to solve the problems of cumbersome preparation process, uneven distribution of doped elements and low oxygen activity of existing electrode materials.

[0006] The present invention also provides applications of this electrode material to improve the overall efficiency of batteries or electrolytic cells.

[0007] To achieve the above objectives, the present invention provides the following technical solution: an electrode material, wherein the electrode material is obtained by solid-phase mixing of Pr y Sr 2-x-y Li x Fe 1.5-z Sn z Mo 0.5 O 6–δ and Ce 0.8 Sm 0.2 O 1.9 The precursor is obtained through in-situ reduction, where x ranges from 0 ≤ x ≤ 0.3, y ranges from 0 ≤ y ≤ 0.3, z ranges from 0 ≤ z ≤ 0.3, and δ represents the oxygen vacancy content; the Pr y Sr 2-x-y Li x Fe 1.5-z Sn z Mo 0.5 O 6–δ The Ce content is 50%–70% by mass. 0.8 Sm 0.2 O 1.9 The mass percentage content is 30% to 50%.

[0008] Furthermore, the electrode material exhibits an oxygen-vacancy-rich perovskite structure comprising uniformly distributed active metal nanoparticles; the active metal nanoparticles are FeSn alloy phases.

[0009] Furthermore, the Pr ySr 2-x-y Li x Fe 1.5-z Sn z Mo 0.5 O 6–δ It is prepared by praseodymium, strontium, lithium, iron, tin and molybdenum ions in the molar ratio of the indicated elements.

[0010] This application also provides a method for preparing the above-mentioned electrode material, including the following steps: S1. Dissolve nitrates of praseodymium, strontium, lithium, iron, tin and molybdenum in water, then add an aqueous solution of ammonia containing a chelating agent, mix well to obtain solution A; S2. Add citric acid to solution A and adjust the pH of solution A to the range of 5-8. Then, stir at a temperature of 80-90°C to carry out a chemical reaction to obtain sol A. S3. The sol A is dried at 100-120°C, and then calcined at 950-1200°C to obtain Pr. y Sr 2-x-y Li x Fe 1.5-z Sn z Mo 0.5 O 6–δ ; S4. Dissolve samarium and cerium nitrates in water, then add an alkaline solution containing ethylenediaminetetraacetic acid, mix well, and obtain solution B; S5. Add citric acid to the solution B and adjust the pH value of the solution B to the range of 5-8. Then, stir at a temperature of 80-90°C to carry out a chemical reaction to obtain sol B. S6. The sol B is dried at 100-120°C, and then calcined at 650-750°C to obtain Ce. 0.8 Sm 0.2 O 1.9 ; S7, the Pr y Sr 2-x-y Li x Fe 1.5-z Sn z Mo 0.5 O 6–δ and the Ce 0.8 Sm 0.2 O 1.9After mixing and ball milling, the mixture is calcined at 700–800°C in air. Then, it is reduced at 650–800°C in a mixed atmosphere of hydrogen and argon to obtain the electrode material.

[0011] Furthermore, the total concentration of metal ions in both sol A and sol B is any value between 0.2 and 0.45 mol / L; In step S1, the molar ratio of the chelating agent to the total metal ions in sol A is (1.5-2):1; in step S4, the molar ratio of the chelating agent to the total metal ions in sol B is also (1.5-2):1.

[0012] Furthermore, the chelating agent is any one of ethylenediaminetetraacetic acid, ethylene glycol, glycine, and oxalic acid.

[0013] Furthermore, in solution A, the molar ratio of citric acid to the total metal ion solution in solution A is (1-1.1):1; In solution B, the molar ratio of citric acid to the total metal ion solution of solution B is (1-1.1):1.

[0014] Furthermore, in step S7, after the calcination treatment is completed, a sieving treatment is performed, and a sieve with a mesh size of 180 to 300 mesh is used for the sieving treatment.

[0015] Further, in step S7, the flow rate of the hydrogen gas is any value between 50 mL / min and 100 mL / min, and the volume of the hydrogen gas accounts for 5% to 10% of the mixed gas.

[0016] This application also provides the application of the above-mentioned electrode materials in hydrocarbon fuel solid oxide fuel cells and solid oxide electrolyzers for the electrochemical reduction of carbon dioxide.

[0017] The beneficial effects of this invention are as follows: the electrode material provided in this application is based on Pr y Sr 2-x-y Li x Fe 1.5- z Sn z Mo 0.5 O 6–δ -Ce 0.8 Sm 0.2 O 1.9This electrode material is prepared by in-situ reduction of a precursor. It comprises uniformly distributed alloy nanoparticles, significantly increasing its specific surface area. A suitable oxygen vacancy concentration helps optimize the ion / electron conduction pathway. Furthermore, the reduction reaction forms active metal nanoparticles on the electrode material's surface, further increasing the active sites and effectively promoting the adsorption and desorption of reactant gases, thus enhancing the electrochemical reaction rate and improving the catalytic activity of the electrode material. This novel electrode material, obtained by effectively controlling the activity of oxygen species and the distribution of active metal sites in a perovskite electrode, exhibits high catalytic activity and excellent stability. It demonstrates excellent anti-carbon deposition performance under hydrocarbon fuel atmospheres and significantly enhances CO2 electroreduction capacity, contributing to the development of high-temperature CO2 electrolysis technology.

[0018] This application provides a simple, economical, and highly reproducible method for preparing electrode materials, with mild and controllable reaction conditions. Furthermore, by adjusting key reaction parameters such as solution pH, calcination temperature, and reduction conditions, the crystal structure of the precursor and the structure of the electrode material can be effectively controlled, thereby ensuring the quality and stability of the electrode material.

[0019] The electrode material provided by this invention significantly increases the three-phase interface length by combining different materials, such as perovskite oxide and oxygen ion conductors. As a fuel electrode material for solid oxide batteries, it exhibits excellent stability and catalytic activity at high temperatures and maintains stable electrochemical performance under high current densities and high temperatures. The presence of alloy nanoparticles provides more active sites for electrochemical reactions, contributing to improved overall battery or electrolyzer performance.

[0020] The electrode material of this invention is also applicable to CO2 reduction reaction (CO2RR), which helps to realize the resource utilization of CO2 and promotes the achievement of carbon neutrality. This electrode material exhibits significant electrochemical performance under a CO2 atmosphere and has the potential to become a key material for clean energy technologies, driving the green energy transition.

[0021] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0022] Attached Figure Description Figure 1 The precursor Pr shown in Embodiment 1 and some other embodiments of the present invention 0.3 Sr 1.6 Li 0.1 Fe 1.3 Sn 0.2 Mo0.5 O 6–δ XRD patterns; Figure 2 This is a SEM image of the electrode material shown in Embodiment 2 of the present invention; Figure 3 This is a TEM image of the electrode material shown in Embodiment 2 of the present invention; Figure 4 The precursor Pr shown in Embodiments 1-3 of this invention y Sr 2-x-y Li x Fe 1.5-z Sn z Mo 0.5 O 6–δ XRD patterns; Figure 5 The graphs show the power density curves of the electrode materials shown in Examples 2, 5 and 6 of this invention in a solid oxide fuel cell at 800°C under a hydrogen atmosphere. Figure 6 This is a power density curve of the electrode material shown in Example 2 of the present invention in a solid oxide fuel cell under hydrogen atmosphere and at different temperatures; Figure 7 This is a power density curve of the electrode material shown in Example 2 of the present invention in a solid oxide electrolytic cell under CO2 atmosphere and at different temperatures. Detailed Implementation

[0023] The technical solutions of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0024] An electrode material is shown in a preferred embodiment of this application, the electrode material being a solid-phase mixture of Pr y Sr 2-x- y Li x Fe 1.5-z Sn z Mo 0.5 O 6–δ and Ce 0.8 Sm 0.2 O 1.9 It is a precursor prepared via an in-situ reduction process. In the electrode material formulation, the precursor Pr... y Sr 2-x-y Li xFe 1.5-z Sn z Mo 0.5 O 6–δ The mass percentage content is 50%–70%, and the precursor Ce 0.8 Sm 0.2 O 1.9 Its mass percentage is 30%–50%. Precursor Pr y Sr 2-x-y Li x Fe 1.5-z Sn z Mo 0.5 O 6–δ In this equation, x ranges from 0 ≤ x ≤ 0.3, y ranges from 0 ≤ y ≤ 0.3, z ranges from 0 ≤ z ≤ 0.3, and δ represents the oxygen vacancy content. By precisely defining the value range and mass percentage of each component, it is possible to ensure that the electrode material has a specific chemical composition and microstructure. This helps to optimize the ionic and electronic conductivity of the electrode material, thereby giving it good electrochemical performance and improving its reactivity and stability in relevant electrochemical devices.

[0025] In one embodiment, the precursor Pr y Sr 2-x-y Li x Fe 1.5-z Sn z Mo 0.5 O 6–δ It is prepared by adding praseodymium, strontium, lithium, iron, tin, and molybdenum ions in molar ratios specified by the indicated elements. This preparation method, which strictly adheres to the principle of stoichiometry, ensures the quality of Pr. y Sr 2-x-y Li x Fe 1.5-z Sn z Mo 0.5 O 6-δ The precision of compound composition and batch-to-batch consistency enable it to play its intended role in electrode materials, such as providing specific active sites or improving ion transport channels, thus providing a reliable basis for subsequent regulation of the microstructure of electrode materials and optimization of their performance.

[0026] In this embodiment or other embodiments, the electrode material exhibits an oxygen-rich defect perovskite structure comprising uniformly distributed active metal nanoparticles. The active metal nanoparticles are an FeSn alloy phase. This nanocomposite structure significantly enhances the electrode material's performance through the synergistic effect between the active metal nanoparticles, oxygen vacancies, and the metal-oxide interface. Excellent ion conductivity is achieved by controlling the oxygen vacancy concentration, providing an efficient channel for charge transport; while the strong interaction between the uniformly dispersed FeSn alloy nanoparticles and the metal-oxide interface exhibits high electrocatalytic activity, effectively reducing the activation energy of the electrochemical reaction. The synergistic effect of these three elements significantly enhances the overall electrochemical performance of the electrode material, significantly increases the reaction rate, lowers the electrode reaction activation energy barrier, and improves long-term operational stability.

[0027] This application also provides a method for preparing the above-mentioned electrode material, which includes the following steps: S1. Dissolve nitrates of praseodymium (Pr), strontium (Sr), lithium (Li), iron (Fe), tin (Sn) and molybdenum (Mo) in water, then add an ammonia solution containing a chelating agent, mix well, and obtain solution A. S2. Add citric acid to solution A and adjust the pH of solution A to the range of 5-8. Then, stir at a temperature of 80-90℃ to carry out a chemical reaction and obtain sol A. S3. Sol A is dried at 100–120°C, and then calcined at 950–1200°C to obtain Pr. y Sr 2-x-y Li x Fe 1.5-z Sn z Mo 0.5 O 6–δ ; S4. Dissolve samarium and cerium nitrates in water, then add ammonia solution containing chelating agent, mix well to obtain solution B; S5. Add citric acid to solution B and adjust the pH of solution B to the range of 5-8. Then, stir at a temperature of 80-90℃ to carry out a chemical reaction and obtain sol B. S6. Sol B is dried at 100–120°C, and then calcined at 650–750°C to obtain Ce. 0.8 Sm 0.2 O 1.9 ; S7, Pr y Sr 2-x-y Li x Fe 1.5-z Snz Mo 0.5 O 6–δ and Ce 0.8 Sm 0.2 O 1.9 After mixing and ball milling, the mixture is calcined at 700–800°C in air. Then, it is reduced at 650–800°C in a mixed atmosphere of hydrogen and argon to obtain the electrode material.

[0028] By combining the sol-gel method with subsequent calcination and reduction treatments, the microstructure and composition of electrode materials can be precisely controlled. Adjusting and optimizing conditions such as temperature and atmosphere in each step facilitates the formation of uniform nanostructures, improves the crystallinity and purity of the material, and thus enhances the electrochemical performance and stability of the electrode material.

[0029] In step S1, by selecting nitrates of praseodymium (Pr), strontium (Sr), lithium (Li), iron (Fe), tin (Sn), and molybdenum (Mo) with excellent solubility properties as starting materials, a transparent and homogeneous solution system can be rapidly formed. This ensures that these metal nitrates are completely dissolved in water, effectively avoiding component segregation problems caused by uneven dissolution of the raw materials, and ensuring the stability and consistency of the composition of the final electrode material. Using an ammonia solution containing a chelating agent as the complexing agent ensures the solubility of the chelating agent and optimizes the chelation process of metal ions.

[0030] In step S2, citric acid is selected as a gelation promoter, which can undergo intermolecular cross-linking reactions with metal-chelating agent complexes, effectively regulating the gelation kinetics of the sol system. Ammonia solution is preferred as a pH adjuster, which not only helps maintain the stable complexation of metal ions by chelating agents such as EDTA and promotes the esterification reaction between citric acid and metal ions, but also avoids introducing other ionic impurities. The esterification reaction promotes the transformation of the solution into a sol state, ultimately forming a transparent sol A.

[0031] In step S3, uniform thermal convection promotes the evaporation of water and organic solvents in sol A at a stable rate, preventing the sol structure from collapsing or cracking due to localized overheating, ultimately yielding a homogeneous, porous dry gel. Before calcination, the dry gel can be ground and sieved. Thorough grinding and sieving ensure uniform particle size, providing a good reactive interface for subsequent high-temperature solid-phase reactions. Calcination ensures the complete decomposition of metal nitrates, citric acid, etc., in the dry gel, while simultaneously promoting the rearrangement of metal ions through solid-state diffusion, forming a Pr with a single perovskite phase structure and good crystallinity. y Sr 2-x-y Li xFe 1.5- z Sn z Mo 0.5 O 6–δ powder.

[0032] In steps S4 to S6, the precursor Ce is preferably prepared using the same or similar methods as in steps S1 to S3. 0.8 Sm 0.2 O 1.9 powder.

[0033] In step S7, to achieve the optimal synergistic effect of electrical conductivity and oxygen ion conductivity, the powders obtained in steps S3 and S6 can be mixed at a specific mass ratio, and ball milling can achieve nanoscale uniform mixing. During calcination, solid-state diffusion can promote the initial bonding between the two phases, forming a stable composite framework structure. Through reduction, some metal ions undergo controlled reduction, while Ce... 0.8 Sm 0.2 O 1.9 The crystal structure stability of the phase is preserved, ultimately yielding an electrode material with a multiphase nanocomposite structure.

[0034] In one embodiment, the total concentration of metal ions in sol A and sol B is any value ranging from 0.2 to 0.45 mol / L. Furthermore, in step S1, the molar ratio of the chelating agent to the total metal ions in sol A is (1.5–2):1; in step S4, the molar ratio of the chelating agent to the total metal ions in sol B is also (1.5–2):1. By controlling the total concentration of metal ions in the sol and the molar ratio of the chelating agent to the metal ions, a stable sol system is formed, ensuring uniform dispersion of metal ions in the sol and avoiding agglomeration caused by excessively high local concentrations. This results in a uniform nanostructure during subsequent processing, improving the consistency of the final electrode material's performance. In this embodiment or other embodiments, the chelating agent can be any one of ethylenediaminetetraacetic acid (EDTA), ethylene glycol, glycine, and oxalic acid. To further optimize the chelation process of metal ions, an ammonia solution containing dissolved EDTA is preferred, with the pH of the solution preferably limited to the range of 8–10. This ensures that the complexation capacity of EDTA for each metal ion is optimally balanced, avoiding incomplete complexation due to excessively low pH and preventing metal hydroxide precipitation due to excessively high pH. Through stirring, the metal ions and EDTA molecules undergo sufficient collision and chelation, ultimately yielding a stable and transparent metal-EDTA complex solution A. Other organic polyacids can also be used instead of citric acid. Organic acids can promote the chelation reaction, enabling the chelating agent to form a stable complex with the metal ions, thereby effectively controlling the release of metal ions and the reaction rate, promoting the formation of a homogeneous sol, and being easily decomposed in subsequent processing without introducing impurities, thus contributing to the acquisition of high-purity electrode materials.

[0035] In one embodiment, the molar ratio of citric acid to the total metal ion solution in solution A is (1-1.1):1; the molar ratio of citric acid to the total metal ion solution in solution B is also (1-1.1):1. By rationally controlling the molar ratio of citric acid to the metal ion solution, the gelation process of the sol can be adjusted, so that the formed sol has a suitable viscosity and structure, which is beneficial to the formation of uniform nanoparticles during subsequent drying and calcination, while avoiding structural defects caused by excessive or insufficient citric acid, thereby improving the performance of the electrode material.

[0036] In one embodiment, in step S7, after calcination, a sieving process is required. During sieving, a sieve of 180-300 mesh can be used. Sieving removes agglomerated particles or large impurities that may exist after calcination, making the precursor particles of the electrode material more uniform in size. This facilitates the formation of a uniform multiphase nanoparticle structure of active metals and metal oxides during the reduction process, improving the reactivity and uniformity of the electrode material. In this embodiment or other embodiments, in step S7, the hydrogen flow rate is any value between 50 mL / min and 100 mL / min, and the volume of hydrogen accounts for 5%-10% of the mixed gas. By adjusting the hydrogen flow rate and its volume percentage in the mixed gas, the atmosphere and intensity of the reduction process can be adjusted, allowing Pr to... y Sr 2-x-y Li x Fe 1.5-z Sn z Mo 0.5 O 6–δ The metal ions in the electrode are moderately reduced to FeSn alloy nanoparticles, avoiding excessive or insufficient reduction that could adversely affect the structure and performance of the electrode material, thus ensuring the acquisition of electrode materials with good electrochemical performance.

[0037] This application also provides the application of the above-mentioned electrode material in hydrocarbon fuel solid oxide fuel cells and solid oxide electrolyzers for the electrochemical reduction of carbon dioxide. Due to its unique composition and structure, this electrode material can provide highly efficient electrocatalytic activity in hydrocarbon fuel solid oxide fuel cells, promoting the oxidation reaction of hydrocarbon fuels and improving the energy conversion efficiency of the battery; it can also effectively catalyze the carbon dioxide reduction reaction in solid oxide electrolyzers for the electrochemical reduction of carbon dioxide, realizing the resource utilization of carbon dioxide, and has broad application prospects and important environmental significance.

[0038] Example 1 S1. Weigh praseodymium nitrate, strontium nitrate, lithium nitrate, ferric nitrate, tin nitrate, and molybdenum nitrate in a molar ratio of 0.3:1.6:0.1:1.3:0.2:0.5, and dissolve them in water. Then, add an ammonia solution containing dissolved ethylenediaminetetraacetic acid to the water in a molar ratio of 2:1 (ethylenediaminetetraacetic acid to metal ions in water), mix thoroughly, and obtain solution A.

[0039] S2. Add citric acid to solution A at a molar ratio of 1:1 (metal ions to citric acid) and adjust the pH of solution A to 6. Then, stir at 85°C to carry out a chemical reaction and obtain sol A.

[0040] S3. Sol A is dried at 110°C, and then calcined at 1050°C to obtain Pr. 0.3 Sr 1.6 Li 0.1 Fe 1.3 Sn 0.2 Mo 0.5 O 6–δ (PSLiFSnM).

[0041] S4. Weigh samarium nitrate and cerium nitrate in a molar ratio of 0.8:0.2, and dissolve them in water. Then, add an ammonia solution containing dissolved ethylenediaminetetraacetic acid to the water in a molar ratio of 2:1 (ethylenediaminetetraacetic acid to metal ions in water), mix thoroughly, and obtain solution B.

[0042] S5. Add citric acid to solution B at a molar ratio of 1:1 for metal ions to citric acid, and adjust the pH of solution B to 7. Then, stir at 85°C to carry out a chemical reaction to obtain sol B.

[0043] S6. Sol B is dried at 110°C, and then calcined at 700°C to obtain Ce. 0.8 Sm 0.2 O 1.9 (SDC).

[0044] S7, the precursor Pr 0.3 Sr 1.6 Li 0.1 Fe 1.3 Sn 0.2 Mo 0.5 O 6–δ and Ce 0.8 Sm 0.2 O 1.9 The materials were mixed at a mass fraction of 60% and 40%, respectively, and then ball-milled before calcination at 750℃ in air. After calcination for 5 hours, a reduction treatment was performed at 800℃ for 5 hours in a mixed gas atmosphere of hydrogen and argon, with a hydrogen flow rate of 80 mL / min and a hydrogen volume accounting for 5% of the total mixed gas volume, to obtain the electrode material, 60% Pr 0.3 Sr 1.6 Li 0.1 Fe 1.3 Sn 0.2 Mo 0.5 O 6–δ -40%Ce 0.8 Sm 0.2 O 1.9 .

[0045] In the precursor Pr 0.3 Sr 1.6 Li 0.1 Fe 1.3 Sn 0.2 Mo 0.5 O 6–δ In the preparation process, to investigate the effects of different reaction conditions on its crystal structure quality and phase purity, and to optimize its preparation process, key reaction parameters were systematically controlled in steps S1 to S3 in some embodiments. Specifically, the effects of changes in the pH value of solution A, calcination temperature, and chelating agent (ethylene glycol or ethylenediaminetetraacetic acid) on the precursor Pr were investigated. 0.3 Sr 1.6 Li 0.1 Fe 1.3 Sn 0.2 Mo 0.5 O 6–δ The influence of crystal structure was investigated, and X-ray diffraction (XRD) was used to analyze the precursor Pr prepared under different conditions. 0.3 Sr 1.6 Li 0.1 Fe 1.3 Sn 0.2 Mo 0.5 O 6–δ Conduct testing and comparative analysis.

[0046] Depend on Figure 1 It can be seen that when the pH of solution A is adjusted to 6 and ethylenediaminetetraacetic acid is used as a complexing agent, the precursor Pr is prepared. 0.3 Sr 1.6 Li 0.1 Fe 1.3 Sn 0.2 Mo 0.5 O 6–δ Its XRD pattern showed the highest match with the standard card. This indicates that under these conditions, the precursor Pr... 0.3 Sr 1.6 Li 0.1 Fe 1.3 Sn 0.2 Mo 0.5 O 6–δ The phase purity is high and the crystal structure is relatively complete. Furthermore, under the same pH value in solution A and using ethylenediaminetetraacetic acid as a complexing agent, when the calcination temperature is 1250℃, the precursor Pr... 0.3 Sr 1.6 Li 0.1 Fe 1.3 Sn 0.2 Mo 0.5 O 6–δThe crystal structure is relatively complete. This indicates that calcination temperature has a significant impact on the crystal structure of the precursor; higher calcination temperatures help improve the integrity of the crystal structure, while lower temperatures may lead to incomplete crystal structures and the formation of more impurity phases. During the preparation process, the calcination temperature can be set at around 1250℃ to ensure its stability and avoid temperature fluctuations that could cause crystal structure instability.

[0047] Example 2 The difference between this embodiment and Embodiment 1 is that: in step S3, the calcination temperature is 1250℃; and, Pr is obtained through steps S1 to S3. 0.2 Sr 1.7 Li 0.1 Fe 1.4 Sn 0.1 Mo 0.5 O 6–δ The final electrode material obtained is 60% Pr 0.2 Sr 1.7 Li 0.1 Fe 1. 4Sn 0.1 Mo 0.5 O 6–δ -40%Ce 0.8 Sm 0.2 O 1.9 It is denoted as 60%PSLiFSnM-40%SDC. The microstructure of this electrode material is as follows: Figure 2 , Figure 3 As shown.

[0048] Depend on Figure 2 , Figure 3 It is known that the electrode material obtained after reduction will form many nanoparticles, namely FeSn alloy phase, on its surface. These FeSn alloys can significantly improve the electrocatalytic activity of the electrode material, thereby effectively reducing the activation energy of the electrochemical reaction and greatly increasing the electrochemical reaction rate.

[0049] Example 3 The difference between this embodiment and embodiment 2 is that Pr is obtained through steps S1 to S3. 0.3 Sr 1.6 Li 0.1 Fe 1.4 Sn 0.1 Mo 0.5 O 6–δ The final electrode material obtained is 60% Pr 0.3 Sr 1.6 Li 0.1 Fe 1.4 Sn 0.1 Mo 0.5 O 6–δ-40%Ce 0.8 Sm 0.2 O 1.9 .

[0050] The precursors Pr prepared in Examples 1-3 were analyzed using X-ray diffraction (XRD). 0.3 Sr 1.6 Li 0. 1Fe 1.4 Sn 0.1 Mo 0.5 O 6–δ The tests were conducted and comparative analyses were performed. The results are as follows: Figure 4 As shown.

[0051] Depend on Figure 4 Examples 2 and 3 further demonstrate that calcination temperature has a significant impact on the crystal structure of the precursor material, affecting its crystal growth, crystallinity, and grain size. Furthermore, different component ratios of the precursor material also lead to changes in the atomic arrangement within the crystal structure, thereby altering the position and intensity of the diffraction peaks.

[0052] Example 4 The difference between this embodiment and embodiment 2 is that: after steps S1 to S3, (Pr) is obtained. 0.4 Sr 1.6 ) 0.95 Li 0.1 Fe 1.3 Sn 0.2 Mo 0.5 O 6–δ The final electrode material obtained is 60% (Pr 0.4 Sr 1.6 ) 0.95 Li 0.1 Fe 1.3 Sn 0.2 Mo 0.5 O 6–δ -40%Ce 0.8 Sm 0.2 O 1.9 .

[0053] Example 5 The difference between this embodiment and Embodiment 2 is that the metal ion solution A does not contain tin nitrate, and Pr is obtained through steps S1 to S3. 0.2 Sr 1.7 Li 0.1 Fe 1.5 Mo 0.5 O 6–δ The final electrode material obtained is 60% Pr 0.2 Sr 1.7 Li 0.1 Fe1.5 Mo 0.5 O 6–δ -40%Ce 0.8 Sm 0.2 O 1.9 It is denoted as 60%PSLiFM-40%SDC.

[0054] Example 6 The difference between this embodiment and Embodiment 2 is that the metal ion solution A does not contain lithium nitrate, and Pr is obtained through steps S1 to S3. 0.2 Sr 1.8 Fe 1.4 Sn 0.1 Mo 0.5 O 6–δ The final electrode material obtained is 60% Pr 0.3 Sr 1.7 Fe 1.3 Sn 0.2 Mo 0.5 O 6–δ -40%Ce 0.8 Sm 0.2 O 1.9 It is denoted as 60%PSFSnM-40%SDC.

[0055] The electrode materials prepared in Examples 2, 5, and 6 were applied to a solid oxide fuel cell, and their electrochemical performance was measured under a hydrogen atmosphere at 800°C. The results are as follows: Figure 5 As shown. During the test, La... 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O 3-δ (LSGM) was used as the electrolyte, with PrBa 0.5 Sr 0.5 Co 1.5 Fe 0.5 O 6-δ (PBSCF) was used as the cathode material, and the electrode materials prepared in Examples 2, 5 and 6 were used as the anode materials.

[0056] Depend on Figure 5It can be seen that, at the same current density, the electrode material prepared in Example 2 exhibits a higher voltage and maintains good voltage stability even at higher current densities; its power density curve also reaches its peak at higher current densities, indicating that the electrode material prepared in Example 2 has good power output performance at high current densities. In contrast, although the electrode material prepared in Example 5 has a similar voltage at low current densities to that prepared in Example 2, its voltage decreases significantly with increasing current density, and its power density peak is also lower. This indicates that the electrode material prepared in Example 5 has poor power output performance at high current densities. The voltage-current density curve and power-current density curve of the electrode material prepared in Example 6 are between those of Examples 2 and 5, showing moderate electrochemical performance. Therefore, the electrode material prepared in Example 2 exhibits good voltage retention and high power output at high current densities, demonstrating its potential advantages in electrochemical applications. This result shows that when the electrode material provided in this application is used in a solid oxide fuel cell, it can significantly improve the performance of the solid oxide fuel cell, and by optimizing the composition ratio of the electrode material, the performance of the electrochemical device can be further optimized.

[0057] The electrode material prepared in Example 2 was applied to a solid oxide fuel cell, and its electrochemical performance was measured under different temperature conditions in a hydrogen atmosphere. The results are as follows. Figure 6 As shown.

[0058] Depend on Figure 6 It is evident that as the temperature increases from 650°C to 800°C, the voltage significantly increases at the same current density, and the peak power density also increases significantly. Specifically, at 800°C, the peak power density is significantly higher than that at other lower temperatures, indicating that the electrode material can output higher power at higher temperatures. This change can be attributed to the increased ion migration rate and improved electrode reaction kinetics resulting from the increased temperature, which in turn reduces polarization effects and enhances the electrochemical performance of the material. Therefore, temperature has a significant impact on the electrochemical performance of this electrode material; increasing the temperature can effectively enhance its voltage and power density, thus demonstrating the high application potential of this electrode material in high-temperature electrochemical devices.

[0059] The electrode material prepared in Example 2 was applied to a solid oxide electrolytic cell for carbon dioxide electrochemical reduction. Its electrochemical performance was measured under a CO2 atmosphere and at different temperatures. The results are as follows: Figure 7 As shown.

[0060] Depend on Figure 7As can be seen, all three curves show a trend of gradually increasing voltage with increasing current density. This indicates a positive correlation between current density and voltage in a CO2 atmosphere. Furthermore, at the same current density, the higher the temperature, the higher the voltage. This is because increased temperature enhances the ion migration and electron conduction capabilities within the electrode material, reducing resistance, thus maintaining a higher voltage at the same current density. In addition, the current density value corresponding to a specific voltage (1.5V) also shows that the higher the temperature, the greater the current density that can be withstood at 1.5V. This further illustrates that the electrode material has better electrical performance and current carrying capacity at high temperatures. Therefore, the electrode material provided in this application exhibits superior voltage-current characteristics under high-temperature conditions, indicating that it has important reference value for relevant high-temperature electrochemical applications, such as electrochemical sensors and energy conversion devices under specific conditions.

[0061] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0062] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. An electrode material, characterized in that, The electrode material is obtained through solid-phase mixing. and The precursor is obtained through in-situ reduction, where x ranges from 0 to 0.3, y ranges from 0 to 0.3, z ranges from 0 to 0.3, and δ represents the oxygen vacancy content. The mass percentage content is 50% to 70%, the aforementioned The mass percentage content is 30% to 50%.

2. The electrode material as described in claim 1, characterized in that, The electrode material exhibits an oxygen-vacancy-rich perovskite structure comprising uniformly distributed active metal nanoparticles; the active metal nanoparticles are FeSn alloy phase.

3. The electrode material as described in claim 1, characterized in that, The It is prepared by praseodymium, strontium, lithium, iron, tin and molybdenum ions in the molar ratio of the indicated elements.

4. The method for preparing the electrode material according to any one of claims 1-3, characterized in that, Includes the following steps: S1. Dissolve nitrates of praseodymium, strontium, lithium, iron, tin and molybdenum in water, then add an aqueous solution of ammonia containing a chelating agent, mix well to obtain solution A; S2. Add citric acid to solution A and adjust the pH of solution A to the range of 5-8. Then, stir at a temperature of 80-90°C to carry out a chemical reaction to obtain sol A. S3. The sol A is dried at 100-120°C, and then calcined at 950-1200°C to obtain... ; S4. Dissolve samarium and cerium nitrates in water, then add an alkaline solution containing ethylenediaminetetraacetic acid, mix well, and obtain solution B; S5. Add citric acid to the solution B and adjust the pH value of the solution B to the range of 5-8. Then, stir at a temperature of 80-90°C to carry out a chemical reaction to obtain sol B. S6. The sol B is dried at 100-120°C, and then calcined at 650-750°C to obtain... ; S7, the above and stated After mixing and ball milling, the mixture is calcined at 700–800°C in air. Then, it is reduced at 650–800°C in a mixed atmosphere of hydrogen and argon to obtain the electrode material.

5. The preparation method according to claim 4, characterized in that, The total concentration of metal ions in sol A and sol B is any value between 0.2 and 0.45 mol / L; In step S1, the molar ratio of the chelating agent to the total metal ions in sol A is (1.5-2):1; in step S4, the molar ratio of the chelating agent to the total metal ions in sol B is also (1.5-2):

1.

6. The preparation method according to claim 4, characterized in that, The chelating agent is any one of ethylenediaminetetraacetic acid, glycine, ethylene glycol, and oxalic acid.

7. The preparation method according to claim 4, characterized in that, In solution A, the molar ratio of citric acid to the total metal ion solution in solution A is (1-1.1):1; In solution B, the molar ratio of citric acid to the total metal ion solution in solution B is (1-1.1):

1.

8. The preparation method according to claim 4, characterized in that, In step S7, after the calcination process is completed, a sieving process is performed, and a sieve with a mesh size of 180 to 300 is used for the sieving process.

9. The preparation method according to claim 4, characterized in that, In step S7, the flow rate of the hydrogen gas is any value between 50 mL / min and 100 mL / min, and the volume of the hydrogen gas accounts for 5% to 10% of the mixed gas.

10. The application of the electrode material according to any one of claims 1 to 3 in hydrocarbon fuel solid oxide fuel cells and solid oxide electrolyzers for the electrochemical reduction of carbon dioxide.

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