Perovskite oxide loaded by high-entropy alloy nanoparticles, preparation method and application

Abstract

The invention relates to a high-entropy alloy loaded composite fuel electrode for a high-temperature solid oxide electrolytic cell, a preparation method and application. Gd < 0.2 > Ce < 0.8 > O < 1.95 >-La < 0.6 > Sr < 1.4 > MnO < 4 + delta > (GDC-LSM) is synthesized by a one-step method to provide mixed ion conductivity for the composite fuel electrode. And then introducing five high-activity high-entropy alloys (HEA) of equimolar metal elements on the surface of the GDC-LSM through a liquid phase method to ensure the size of the alloy. Through the catalytic effect of the high-entropy alloy, the problem that CO2 is excessively adsorbed by single metal such as Fe is solved, and meanwhile the reaction activity of CO2 electrolysis is provided for the composite fuel electrode. Based on the excellent mixed ion / electron conductivity of the GDC-LSM carrier and the excellent stability in a reducing atmosphere, the high-entropy alloy FeCoNiCuRu can provide efficient CO2 reduction reaction activity, and shows excellent CO2 reduction reaction performance under cooperation.

Description

Technical Field

[0001] This invention relates to a perovskite oxide supported on high-entropy alloy nanoparticles, its preparation method, and its applications, belonging to the field of fuel cell technology. Background Technology

[0002] Solid oxide electrolyzer (SOEC) technology Figure 1 SOEC (Solar Energy Concentrator) can effectively utilize renewable electrical energy and solar thermal energy to efficiently convert CO2 into directly usable fuel (CO), thus achieving CO2 recycling. Due to its advantages in energy conversion efficiency, waste heat utilization, feedstock diversity, and environmental friendliness, SOEC has the potential to become an important link between electricity, fuel gas, and heat networks. SOEC consists of a porous hydrogen electrode (cathode), a porous oxygen electrode (anode), and an electrode capable of conducting oxygen ions (O2). 2- It consists of three main components: a dense ceramic electrolyte, a CO2 source, and an O2 source. CO2 is electrochemically reduced at the cathode to produce fuel gas (CO) and O2. 2- O 2- The electrolyte conducts the charge to the anode side, where it is recombined into O2. Therefore, the development of highly active and thermally stable fuel electrode materials is of great significance for the efficient and stable operation of SOEC.

[0003] However, one of the technical challenges of SOEC is the insufficient catalytic activity and stability of the CO2RR fuel electrode, which is also a major obstacle to the commercialization of SOEC. Despite this, research on SOEC fuel electrodes has progressed from early nickel-based electrodes to perovskite electrodes, and finally to the widely studied composite electrodes. Currently reported advanced composite electrodes struggle to achieve excellent catalytic activity while maintaining superior stability. Furthermore, the active particles in these composite electrodes face problems such as particle agglomeration, thus requiring more advanced SOEC fuel electrodes. Recently, high-entropy alloys (HEAs) have attracted increasing interest, offering a wide range of possibilities for tuning material functions, including electrocatalysis, ion storage, and superconductivity. Due to their crystal structure, synthesis effects, and the synergistic effects of different ions, HEAs can exhibit unique properties, possessing increased entropy and lower Gibbs free energy, providing excellent stability, and have been successfully used in SOEC fuel electrodes.

[0004] Zhu et al. synthesized a series of novel Fe using the sol-gel method. 0.1 Co 0.35 Ni 0.35 Cu 0.1 Mo 0.1(FCNCM) high-entropy alloy, and explored the possibility of using high-entropy alloy as a solid oxide electrolysis cell (SOEC) fuel electrode for the efficient and stable co-electrolysis of H2O and CO2 to produce syngas. The FCNCM / gadolinium-doped ceria (CGO) composite fuel electrode-based cell achieved a maximum power density of 0.48 W cm -2 in SOFC mode, which was more than 20% higher than that of traditional Ni / CGO-based cells. In addition, a measurable working current density of 878 mA cm -2 was achieved at a co-electrolysis voltage of 1.5 V and an input H2O / CO2 gas ratio of 2 / 1, which was an 18% increase compared to the Ni cell. The proportion of CO in the co-electrolysis product was also significantly increased compared to the Ni-based cell. This fully demonstrates the advancement of using high-entropy alloy as a SOEC fuel electrode (Non-patent document 1). At the same time, the composition of multiple elements regulates the entropy value of the alloy, thereby improving the stability of the material, but the direct preparation of the alloy inevitably leads to the agglomeration and coarsening of the alloy, reducing the electrochemical activity of the SOEC fuel electrode material.

[0005] Non-patent document 1: Tong J, Ni N, Zhou B, et al. Toward High CO Selectivity and Oxidation Resistance Solid Oxide Electrolysis Cell with High-Entropy Alloy [J]. ACS Catalysis, 2024, 14, 5, 2897-2907. SUMMARY

[0006] The technical problem to be solved by the present application is that in the existing application in the CO2RR process in the solid oxide electrolysis cell (SOEC), due to the agglomeration of active particles, the perovskite structure is inevitably destroyed by the reducing atmosphere, resulting in the problem of catalytic activity decay and low operation durability. The present application proposes a composite fuel electrode of high-entropy alloy loaded perovskite oxide, which has Fe 0.2 Co 0.2 Ni 0.2 Cu 0.2 Ru 0.2 @Gd 0.2 Ce 0.8 O 1.95 -La 0.6 Sr 1.4 MnO 4+δA general formula of the high-entropy alloy nanoparticles supported perovskite oxide (FeCoNiCuRu@GDC-LSM), and the method aims to improve the CO2RR activity of the SOEC fuel electrode. The high-entropy alloy is directly loaded on the traditional GDC-LSM composite electrode by a liquid phase method. Due to the combination of the characteristics of active metal elements in the alloy, the adsorption and activation degree of CO2 by the alloy are effectively considered, the promotion of the activation and conversion of CO2 by the material is realized, and the CO2RR activity of the FeCoNiCuRu@GDC-LSM fuel electrode in SOEC is greatly enhanced. In addition, under the effective promotion of the increase of entropy, the structural stability of the FeCoNiCuRu@GDC-LSM fuel electrode is obviously improved, so that the single cell performs well in the short-term stability test.

[0007] A high-entropy alloy nanoparticle supported perovskite oxide includes a core material and an alloy material coated outside the core material;

[0008] The core material is a gadolinium-doped cerium dioxide and lanthanum-strontium-manganese-oxygen-perovskite composite (GDC-LSM);

[0009] The alloy material is an alloy composed of iron, cobalt, nickel, copper, and ruthenium.

[0010] The gadolinium-doped cerium dioxide and lanthanum-strontium-manganese-oxygen-perovskite composite has a chemical formula of Gd 0.2 Ce 0.8 O 1.95 -La 0.6 Sr 1.4 MnO 4+δ ; and δ is the content of oxygen vacancies.

[0011] The high-entropy alloy nanoparticles have a nanoscale particle size.

[0012] The alloy material has a chemical formula of Fe x Co y Ni z Cu m Ru n , wherein x, y, z, m, and n are greater than 0 and x+y+z+m+n=1.

[0013] The alloy material has x=y=z=m=n=0.2; the particle size is 100-300 nm; and the molar proportion of the ruthenium element in the alloy is 10%-30%.

[0014] The preparation method of the perovskite oxide includes the following steps:

[0015] Step 1, according to the stoichiometric ratio, the Gd salt, Ce salt, La salt, Sr salt, Mn salt is dissolved in water, after adding the complexing agent and adjusting the pH, the reaction is carried out to generate a gel; the gel is dried and calcined to obtain the GDC-LSM powder;

[0016] Step 2, according to the selected stoichiometric ratio, a certain amount of Fe salt, Co salt, Ni salt, Cu salt, Ru salt is dissolved in water, and the synthesized GDC-LSM powder is added, and the heating and stirring is continued until the water is evaporated, and then the final electrode material is obtained after calcination and reduction.

[0017] In step 1, the molar ratio of total metal ions: EDTA: CA: ammonia is 1:0.5-1.5:1-3:3-20, the drying condition is 140-160℃ baking for 1-10h; the calcination temperature is 900-1200℃ calcination for 1-10h, and the heating rate is 2-8℃ / min.

[0018] In step 2, during the heating and stirring until the water is evaporated, the temperature is 50-80℃, and the stirring evaporation is 5-10h; the calcination temperature is 900-1200℃ calcination for 1-10h, and the heating rate is 2-8℃ / min; the reduction temperature is 800-1000℃ reduction for 5-20h, the atmosphere is 10% H2 / N2, and the heating rate is 2-8℃ / min.

[0019] The above perovskite oxide is used in a solid oxide electrolysis cell or an oxygen ion conductor fuel electrode.

[0020] The electrolysis cell is used for CO2 electrolysis to prepare CO.

[0021] The perovskite oxide is used to improve the highest adsorption temperature and chemical adsorption amount of CO2.

[0022] The method for improving the chemical adsorption amount of CO2 by the perovskite oxide loaded with high-entropy alloy nanoparticles, characterized in that the chemical adsorption amount of CO2 of the perovskite oxide is improved by 100-120% compared with GDC-LSM, and is improved by 30-40% compared with GDC-LSM loaded with iron, cobalt and nickel ternary alloy on the surface.

[0023] The beneficial effects of the present application are:

[0024] (1) The present application synthesizes high-entropy alloy solid oxide fuel electrode material active components by combining one-step sol-gel method and liquid phase method, the elements in the material are uniformly distributed, the synthesis method is simple and efficient, Ru can form an alloy with many metals (FeRu, FeNiRu, etc.), and the selection of Ru can ensure that it is easier to form an alloy with other metals during preparation.

[0025] (2) The composite electrode material prepared by traditional methods such as direct physical mixing, impregnation and nanoparticle precipitation can improve the activity of the electrode to a certain extent, but inevitably reduces the stability of the material. Therefore, based on the perovskite material with excellent stability under hydrogen atmosphere, GDC-LSM is synthesized by one-step sol-gel method to ensure the excellent mixed ion / electron conduction performance of the electrode matrix. The high-entropy alloy is dispersed on the surface of GDC-LSM by liquid phase method to provide CO2RR activity for the whole fuel electrode.

[0026] (3) The chemical adsorption energy of the interaction between transition metals and CO2 is related as follows: Fe (-33.4 kcal / mol) < Co (-9.6 kcal / mol) < Ni (-1.1 kcal / mol) < Cu (+17.3 kcal / mol). Fe with the strongest chemical adsorption energy can effectively adsorb CO2, so that iron-based materials are widely used for electrolysis of CO2. The entropy engineering strategy based on perovskite oxides has been proved to effectively improve the adsorption activity and stability of the cathode material to CO2. Therefore, by mixing several transition metals, the properties of each metal can be effectively combined, the entropy value of the alloy is improved, and the adsorption and activation process of CO2 by the metal can be further optimized, thereby improving the activity and efficiency of the FeCoNiCuRu@GDC-LSM fuel electrode in the conversion of CO2 to CO in SOEC.

[0027] (4) FeCoNiCuRu@GDC-LSM is used as an excellent fuel electrode material, and the current density of electrolysis of CO2 is 2.34 A cm -2 -2 at 800℃, 1.5V in the electrolysis cell mode, which is 207.9% higher than that of GDC-LSM under the same conditions. At the same time, the Faraday efficiency of CO2 conversion is more than 95% in the range of 800℃, 1.2-2.4 A cm -2 -2, and the CO yield is 16.53 mL min -2 -2 cm -1 -2 at 2.4 A cm -2 . BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is the XRD pattern of LSM, GDC and LSM-GDC electrode materials at room temperature.

[0029] Figure 2 is the XRD pattern of FeCoNiCuRu@GDC and FeCoNiCuRu@GDC-LSM electrode materials before and after reduction at 850℃, 10% H2 / N2 atmosphere for 5h;

[0030] Figure 3is the SEM image of FeCoNiCuRu@GDC electrode material after reduction at 850℃ under 10% H2 / N2 atmosphere for 5h;

[0031] Figure 4 is the high magnification TEM image of FeCoNiCuRu alloy formed after reduction at 850℃ under 10% H2 / N2 atmosphere for 5h;

[0032] Figure 5 is the mapping image of FeCoNiCuRu alloy formed after reduction at 850℃ under 10% H2 / N2 atmosphere for 5h;

[0033] Figure 6 is the CO2 temperature programmed desorption graph of GDC-LSM, FCN@GDC-LSM and HEA@GDC-LSM and the integral area graph of CO2 desorption curve in the range of 600-900℃;

[0034] Figure 7 is the impedance graph of FeCoNiCuRu@GDC and LSM electrode materials prepared with different mixing ratios on symmetrical cells under 50% CO-CO2 atmosphere in the range of 850-700℃;

[0035] Figure 8 is the impedance comparison graph and the activation energy graph of FeCoNiCuRu@GDC and LSM electrode materials with different mixing ratios on symmetrical cells under 50% CO-CO2 atmosphere at 800℃;

[0036] Figure 9 is the I-V curve and the impedance graph at 1.5V of GDC-LSM|LSGM|BSGF electrolytic cell in electrolytic cell mode in the temperature range of 700-850℃;

[0037] Figure 10 is the I-V curve and the impedance graph at 1.5V of FCN@GDC-LSM|LSGM|BSGF electrolytic cell in electrolytic cell mode in the temperature range of 700-850℃;

[0038] Figure 11 is the I-V curve and the impedance graph at 1.5V of FeCoNiCuRu@GDC-LSM|LSGM|PBSGF electrolytic cell in electrolytic cell mode in the temperature range of 700-850℃;

[0039] Figure 12 is the impedance graph and the corresponding DRT treatment of FeCoNiCuRu@GDC-LSM|LSGM|PBSGF electrolytic cell under different voltages at 800℃;

[0040] Figure 13The DRT treatment of the impedance diagram of a single cell with GDC-LSM and FeCoNiCuRu@GDC-LSM as electrodes at 800℃ and 1.5V;

[0041] Figure 14 The image shows the SEM morphology of a single cell with FeCoNiCuRu@GDC-LSM as the electrode.

[0042] Figure 15 The figure shows the Faraday efficiency of the FeCoNiCuRu@GDC-LSM fuel electrode for CO2 electrolysis at different current densities at 800℃. Detailed Implementation

[0043] This invention provides a solid oxide electrolyzer fuel electrode material with excellent electrochemical performance, specifically with the molecular formula: Fe. x Co y Ni z Cu m Ru n @Gd 0.2 Ce 0.8 O 1.95 -La 0.6 Sr 1.4 MnO 4+δ (FeCoNiCuRu@GDC-LSM), where δ represents the oxygen vacancy content; and x,y,z,m,n>0, and x+y+z+m+n=1, belongs to the field of solid oxide electrolytic cell fuel electrode materials. The alloy metal is dispersed on the surface of GDC-LSM using a liquid-phase method, resulting in a more uniform particle size distribution of the high-entropy alloy, effectively expanding the reactive sites. Simultaneously, using GDC-LSM perovskite as the electrode substrate effectively expands the mixed ionic / electronic conductivity of the electrode material. The uniform mixing of multiple elements effectively increases the alloy's entropy value, promoting its stability at high temperatures, and also enhances the material's CO2 RR capability and CO2 conversion capacity in electrolytic cell mode through the interactions between elements. In electrolytic cell mode, the FeCoNiCuRu@GDC-LSM fuel electrode exhibits a current density of -2.34 A cm⁻¹ at 800℃ and 1.5V. -2 At the same time, at 800℃, 1.2-2.4Acm -2 The Faraday efficiency of CO2 conversion within the specified range reached over 95%, at 2.4 Acm. -2 The CO yield reached 16.53 mL / min. -1 cm -2 This invention develops a high-performance solid oxide fuel electrode material and its preparation method, which greatly improves the electrochemical performance and CO2 conversion capacity of solid oxide electrolyzers.

[0044] In a first aspect, the present application provides:

[0045] A solid oxide fuel electrode material, whose molecular structure is: Fe x Co y Ni z Cu m Ru n @Gd 0.2 Ce 0.8 O 1.95 -La 0.6 Sr 1.4 MnO 4+δ (FeCoNiCuRu@GDC-LSM), wherein δ is the content of oxygen vacancies; and x, y, z, m, n > 0, and x + y + z + m + n = 1.

[0046] Preferably, the specific molecular structure of the solid oxide fuel electrode material is: Fe 0.2 Co 0.2 Ni 0.2 Cu 0.2 Ru 0.2 @Gd 0.2 Ce 0.8 O 1.95 -La 0.6 Sr 1.4 MnO 4+δ (FeCoNiCuRu@GDC-LSM).

[0047] In a second aspect, the present application provides:

[0048] The preparation method of the above-mentioned solid oxide fuel electrode material is prepared by one-step sol-gel method combined with liquid phase method according to the element ratio.

[0049] The sol-gel method comprises the following steps:

[0050] According to the stoichiometric ratio, Gd salt, Ce salt, La salt, Sr salt and Mn salt are dissolved in water, a complexing agent is added and pH is adjusted, and then the reaction is carried out to generate a gel; the gel is dried and calcined to obtain GDC-LSM powder.

[0051] In an embodiment, the molar ratio of total metal ions: EDTA: CA: ammonia is 1: 0.5-1.5: 1-3: 3-20.

[0052] In an embodiment, the drying condition is baking at 140-160℃ for 1-10h.

[0053] In an embodiment, the calcination temperature is 900-1200℃ for 1-10h, and the heating rate is 2-8℃ / min.

[0054] The liquid phase method comprises the following steps:

[0055] According to the selected stoichiometric ratio, a certain amount of Fe salt, Co salt, Ni salt, Cu salt, Ru salt is weighed and dissolved in water, and the above synthesized GDC-LSM powder is added in proportion, and heating and stirring are continued until the water is evaporated, and then calcination and reduction are carried out to obtain the final electrode material.

[0056] In one embodiment, the heating and stirring process to evaporate the water is 50-80℃, and the stirring evaporation time is 5-10h.

[0057] In one embodiment, the calcination temperature is 900-1200℃, the calcination time is 1-10h, and the heating rate is 2-8℃ / min.

[0058] In one embodiment, the reduction temperature is 800-1000℃, the reduction time is 5-20h, the atmosphere is 10% H2 / N2, and the heating rate is 2-8℃ / min.

[0059] The third aspect of the present application provides:

[0060] The above-mentioned solid oxide fuel electrode material is used in a solid oxide electrolysis cell or an oxygen ion conductor fuel electrode.

[0061] In one embodiment, the above-mentioned use is to improve the CO2RR capability of the electrode material and the efficiency of the electrochemical conversion of CO2 to CO.

[0062] In one embodiment, the electrolyte used in the above-mentioned solid oxide electrolysis cell is La 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O 3-δ (LSGM).

[0063] Example 1

[0064] This example provides a preparation method of a solid oxide electrolysis cell fuel electrode material Fe 0.2 Co 0.2 Ni 0.2 Cu 0.2 Ru 0.2 @Gd 0.2 Ce 0.8 O 1.95 -La 0.6 Sr 1.4 MnO 4+δ , and the specific steps are as follows:

[0065] Step 1:

[0066] (1) Take stoichiometric amounts of 6.9735 g of gadolinium nitrate hexahydrate, 26.8348 g of cerium nitrate hexahydrate, 12.9903 g of lanthanum nitrate hexahydrate, 14.8141 g of strontium nitrate, and 12.2545 g of manganese acetate tetrahydrate, and dissolve them in an appropriate amount of deionized water. Take 58.448 g of ethylenediaminetetraacetic acid and 84.056 g of citric acid monohydrate as complexing agents in a molar ratio of ethylenediaminetetraacetic acid: citric acid monohydrate: metal ions = 1:2:1, and add an appropriate amount of deionized water.

[0067] (2) Add the obtained complexing agent to the dissolved metal ion solution, and then add an appropriate amount of ammonia water to adjust the pH of the solution to the range of 7-8, and then heat and stir until the water evaporates to obtain a gel-like substance.

[0068] (3) Place the gel-like substance in an oven at 250°C to remove water to obtain a precursor.

[0069] (4) Place the obtained precursor in a high-temperature furnace at 1150°C and calcine for 10 h to finally obtain Gd 0.2 Ce 0.8 O 1.95 -La 0.6 Sr 1.4 MnO 4+δ (GDC-LSM) powder.

[0070] Step 2:

[0071] (1) Take stoichiometric amounts of 1.01 g of iron nitrate nonahydrate, 0.7276 g of cobalt nitrate hexahydrate, 0.7270 g of nickel nitrate hexahydrate, 0.6039 g of copper nitrate, and 0.6536 g of ruthenium chloride trihydrate, and dissolve them in an appropriate amount of deionized water.

[0072] (2) Add 22.2374 g of the GDC-LSM powder in Step 1 to the obtained metal ion solution, and then heat and stir until the water evaporates to obtain a dry powder.

[0073] (3) Place the above dry powder in a muffle furnace at 1000°C to calcine and obtain a precursor.

[0074] (4) Place the obtained precursor in a tube furnace at 850°C, and pass 10% H2 / N2 to reduce for 5 h to finally obtain FeCoNiCuRu@GDC-LSM (HEA@GDC-LSM) electrode powder.

[0075] Example 2

[0076] This example provides a Fe 0.2 Co 0.2 Ni 0.2 Cu 0.2 Ru0.2 @Gd 0.2 Ce 0.8 O 1.95 -La 0.6 Sr 1.4 MnO 4+δ The preparation and testing method of the symmetrical battery with the electrode is as follows:

[0077] (1) 1g of the electrode powder Fe 0.2 Co 0.2 Ni 0.2 Cu 0.2 Ru 0.2 @Gd 0.2 Ce 0.8 O 1.95 -La 0.6 Sr 1.4 MnO 4+δ in a high-energy ball mill, and 10mL of isopropyl alcohol, 2mL of ethylene glycol, and 0.8mL of glycerol are added thereto. After ball milling at 400r / min for 30min, the electrode slurry is obtained.

[0078] (2) The prepared LSGM electrolyte sheet is placed on a heating table at 150℃, and the prepared electrode slurry is uniformly sprayed on both sides of the electrolyte sheet by inert gas and a spray gun. After the liquid is completely evaporated, the sprayed electrolyte sheet is calcined in a high-temperature furnace at 1000℃ for 2h to obtain the required symmetrical battery, which is used for the test of electrode polarization impedance in the temperature range of 700-850℃. The polarization impedance of the symmetrical battery measured at 800℃ in a 50% CO-CO2 atmosphere is 1.72Ωcm 2 .

[0079] Example 3

[0080] This example provides a method for preparing and testing a single cell with Fe 0.2 Co 0.2 Ni 0.2 Cu 0.2 Ru 0.2 @Gd 0.2 Ce 0.8 O 1.95 -La 0.6 Sr 1.4 MnO 4+δ as the fuel electrode, and the specific steps are as follows:

[0081] (1) 1g of the electrode powder Fe 0.2 Co 0.2 Ni 0.2 Cu 0.2 Ru 0.2@Gd 0.2 Ce 0.8 O 1.95 -La 0.6 Sr 1.4 MnO 4+δ In a high-energy ball mill, 10 mL of isopropyl alcohol, 2 mL of ethylene glycol, and 0.8 mL of glycerol were added, and the electrode slurry was obtained after ball milling at 400 r / min for 30 min.

[0082] (2) The prepared PBSCF-LSGM half-cell sheet was placed on a heating table at 150°C, and the prepared electrode slurry was uniformly sprayed on the surface of the electrolyte side by inert gas and a spray gun. After the liquid was completely evaporated, the sprayed electrolyte sheet was placed in a high-temperature furnace at 1000°C and calcined for 2h to obtain the required single cell, which was used for testing the performance of the battery in the temperature range of 700-850°C in the electrolysis of CO2. The current density obtained by the battery in the electrolysis cell mode at 800°C, 1.5V was-2.34 A cm -2 .

[0083] Comparative Example 1

[0084] The present embodiment provides a preparation method of a solid oxide electrolysis cell fuel electrode material Gd 0.2 Ce 0.8 O 1.95 -La 0.6 Sr 1.4 MnO 4+δ , and the specific steps are as follows:

[0085] (1) The stoichiometric amounts of 6.9735 g of gadolinium nitrate hexahydrate, 26.8348 g of cerium nitrate hexahydrate, 12.9903 g of lanthanum nitrate hexahydrate, 14.8141 g of strontium nitrate, and 12.2545 g of manganese acetate tetrahydrate were weighed and dissolved in an appropriate amount of deionized water. 58.448 g of ethylenediaminetetraacetic acid and 84.056 g of citric acid monohydrate were weighed as complexing agents according to the molar ratio of ethylenediaminetetraacetic acid: citric acid monohydrate: metal ion = 1:2:1, and an appropriate amount of deionized water was added.

[0086] (2) The obtained complexing agent was added to the dissolved metal ion solution, and an appropriate amount of ammonia water was added to adjust the pH range of the solution to 7-8, and then heated and stirred until the water evaporated to obtain a gel-like substance.

[0087] (3) The gel-like substance was placed in an oven at 250°C to remove water to obtain a precursor.

[0088] (4) The obtained precursor was placed in a high-temperature furnace at 1150°C and calcined for 10h to finally obtain the electrode powder.

[0089] Comparative Example 2

[0090] The embodiment provides a solid oxide electrolysis cell fuel electrode material Fe 5 / 3 Co 5 / 3 Ni 5 / 3 @Gd 0.2 Ce 0.8 O 1.95 -La 0.6 Sr 1.4 MnO 4+δ A preparation method of the material is as follows:

[0091] Step 1:

[0092] (1) The stoichiometric 6.9735g gadolinium nitrate hexahydrate, 26.8348g cerium nitrate hexahydrate, 12.9903g lanthanum nitrate hexahydrate, 14.8141g strontium nitrate, and 12.2545g manganese acetate tetrahydrate are weighed and dissolved in a proper amount of deionized water. 58.448g ethylenediaminetetraacetic acid and 84.056g citric acid monohydrate are weighed as complexing agents according to the molar ratio of ethylenediaminetetraacetic acid: citric acid monohydrate: metal ion = 1:2:1 and added with a proper amount of deionized water.

[0093] (2) The obtained complexing agent is added to the dissolved metal ion solution, and then a proper amount of ammonia water is added to adjust the pH range of the solution to 7-8, and then heated and stirred until the water evaporates to obtain a colloidal substance.

[0094] (3) The colloidal substance is placed in an oven at 250 DEG C to remove water to obtain a precursor.

[0095] (4) The obtained precursor is placed in a high-temperature furnace at 1150 DEG C and calcined for 10h to finally obtain Gd 0.2 Ce 0.8 O 1.95 -La 0.6 Sr 1.4 MnO 4+δ (GDC-LSM) powder.

[0096] Step 2:

[0097] (1) The stoichiometric 6.9735g gadolinium nitrate hexahydrate, 26.8348g cerium nitrate hexahydrate, 12.9903g lanthanum nitrate hexahydrate, 14.8141g strontium nitrate, and 12.2545g manganese acetate tetrahydrate are weighed and dissolved in a proper amount of deionized water. 58.448g ethylenediaminetetraacetic acid and 84.056g citric acid monohydrate are weighed as complexing agents according to the molar ratio of ethylenediaminetetraacetic acid: citric acid monohydrate: metal ion = 1:2:1 and added with a proper amount of deionized water.

[0098] (2) 22.2374g GDC-LSM powder in step 1 is added to the obtained metal ion solution, and then heated and stirred until the water evaporates to obtain dry powder.

[0099] (3) The above dry powder is placed in a muffle furnace at 1000 DEG C to obtain a precursor.

[0100] (4) The obtained precursor was placed in a tube furnace at 850°C, and 10% H2 / N2was introduced for 5h to obtain the final FCN@GDC-LSM electrode powder.

[0101] Characterization results

[0102] 1. X-ray diffraction (XRD) characterization

[0103] Figure 1 is the XRD pattern of LSM, GDC and LSM-GDC electrode materials at room temperature. The characteristic peaks of LSM-GDC are consistent with the diffraction peaks of LSM and GDC, and no other impurity peaks are generated.

[0104] Figure 2 is the XRD pattern of FeCoNiCuRu@GDC and FeCoNiCuRu@GDC-LSM electrode materials before and after reduction at 850°C, 10% H2 / N2for 5h; both samples show consistent phase structure before reduction, which means that the electrode material with LSM as the carrier can maximize the stability of the electrode material while providing mixed ionic and electronic conductivity for the fuel electrode in a reducing atmosphere. In addition, in order to eliminate the influence of LSM diffraction peaks, the alloy shape was observed on FeCoNiCuRu@GDC. In addition to the diffraction peaks of GDC, obvious alloy diffraction peaks appeared near 42° and 50°, indicating that reduction can promote the formation of alloy.

[0105] 2. Scanning electron microscope (SEM) characterization

[0106] Figure 3 is the SEM image of FeCoNiCuRu@GDC electrode material after reduction at 850°C, 10% H2 / N2. According to the SEM image, it can be clearly seen that the electrode powder still maintains a porous structure after reduction treatment, and no sintering occurs, and the powder surface is loaded with clear and uniform nanoparticles. From the SEM image, it can be clearly seen that the particle size of the alloy nanoparticles is about 200nm.

[0107] 3. Transmission electron microscope (TEM) characterization

[0108] Figure 4 is the high-magnification TEM image of FeCoNiCuRu; the interplanar spacing of FeCoNiCuRu alloy is 0.164nm, corresponding to the (200) crystal plane.

[0109] Figure 5is the mapping result of TEM, in which the elements of Fe, Co, Ni, Cu and Ru in the high-entropy alloy are uniformly distributed in the material. This proves that the preparation of high-entropy alloy is achieved at 850℃ in an atmosphere of 10% H2 / N2.

[0110] 4. CO2 temperature programmed desorption (CO2-TPD) characterization

[0111] Figure 6 is the CO2 real-time desorption signal (CO2-TPD) and the integral area graph of CO2 desorption curve in the range of 600-900℃ of the three materials GDC-LSM, FCN@GDC-LSM and HEA@GDC-LSM after pre-adsorbing for two hours at 300℃ in pure CO2 atmosphere, using QMS 403Aё(Germany, Ritter) to monitor the process of heating the materials from room temperature to 1000℃. The CO2 desorption behaviors of the three materials are similar, and the CO2 desorption occurring above 300℃ is due to the chemical adsorption of CO2 by the materials. The desorption peaks of GDC-LSM, FCN@GDC-LSM and HEA@GDC-LSM at high temperature appear at 770.2, 776.1 and 804.2℃, respectively, indicating the improvement of the alloy's ability to bind CO2 molecules. The higher the peak temperature, the stronger the chemical bonding ability of CO2 molecules to the surface of the material. In the process of CO2 electrolytic reduction (CO2RR), CO2 molecules need to be chemically adsorbed by the electrode material first. Stronger adsorption ability is usually conducive to the subsequent C=O double bond breaking and reduction reaction, therefore, HEA@GDC-LSM has the strongest CO2 chemical adsorption capacity, laying a foundation for high-efficiency catalysis. At the same time, the integral area of CO2 desorption curve in the range of 600-900℃ of HEA@GDC-LSM is 3.64*10 -8 A℃, while the integral areas of GDC-LSM and FCN@GDC-LSM are 1.78*10 -8 and 2.70*10 -8A °C. Compared with GDC-LSM and FCN@GDC-LSM, the CO2 desorption amount of HEA@GDC-LSM increased by 104.5% and 34.8%, respectively. Obviously, FCN@GDC-LSM material exhibits improved CO2 adsorption capacity with the surface loading of FeCoNi alloy on GDC-LSM, the larger the peak area, the more CO2 molecules the material can adsorb under the same conditions. This indicates that HEA@GDC-LSM has a larger adsorption capacity, and more chemical adsorption sites mean more simultaneous reaction sites, which macroscopically manifests as higher reaction rate and current density. At the same time, when the alloy composition is further increased to FeCoNiCuRu, the characteristics of high-entropy alloy make HEA@GDC-LSM electrode material exhibit the highest adsorption temperature and chemical adsorption amount of CO2, which is conducive to promoting the CO2RR process of the material. The introduction of high-entropy alloy (compared with GDC-LSM) significantly increases the number and adsorption strength of CO2 chemical adsorption sites on the material surface, and the "high-entropy" design (compared with FCN@GDC-LSM), that is, the introduction of Cu and Ru, further maximizes this adsorption capacity.

[0112] 5. Electrochemical impedance test

[0113] Figure 7 is the impedance diagram of the electrode material prepared by mixing FeCoNiCuRu@GDC and LSM in different proportions on the symmetrical cell under 850-700 °C, 50% CO-CO2 atmosphere. It can be clearly seen from it that as the test temperature decreases, the symmetrical cell polarization impedance increases, which indicates that the CO2RR in the solid oxide electrolysis cell is greatly affected by temperature, and high temperature is conducive to promoting the activation of CO2.

[0114] Figure 8 is the impedance specific comparison results and the corresponding activation energy results of different mixing proportions under 50% CO-CO2 atmosphere, 800 °C. Under the atmosphere of 50% CO-CO2, the ASR of the mixed electrode with a mixing ratio of 30%-70% at 800 °C is 2.49, 1.95, 1.72 and 1.79 Ωcm 2 , respectively. The ASR of the fuel electrode mixed with FeCoNiCuRu@GDC and LSM at a ratio of 50% is the smallest. The activation energy corresponding to the mixing ratio of 30%-70% is 1.19, 1.08, 1.09 and 1.09 eV, respectively, further confirming that mixing an appropriate amount of LSM can effectively improve the activation ability of the electrode to CO2.

[0115] 6. Electrolysis cell performance test

[0116] Figure 9 , Figure 10 and Figure 11These are GDC-LSM|LSGM|PBSGF, FCN@GDC-LSM|LSGM|PBSGF, and FeCoNiCuRu@GDC-LSM|LSGM|PBSGF electrolyzers at 100 mL / min. -1 The temperature was increased to 850℃ under a pure CO2 atmosphere, and the temperature was decreased in 50℃ increments to obtain IV curves in electrolytic cell mode within the temperature range of 700-850℃; the GDC-LSM|LSGM|PBSGF electrolytic cell was used in 100mL min... -1 Under a pure CO2 atmosphere, the current densities at 700, 750, 800, and 850 °C are -0.26, -0.41, -0.75, and -1.3 mA cm⁻¹, respectively. -2 (1.5V). The current densities of FeCoNiCuRu@GDC-LSM|LSGM|PBSGF under the same conditions were -0.43, -0.74, -1.18, and -1.8 mA cm⁻¹, respectively. -2 (1.5V). The current densities of FeCoNi@GDC-LSM|LSGM|PBSGF under the same conditions were -1.17, -1.78, -2.34, and -3.32 mA cm⁻¹, respectively. -2 (1.5V). It can be seen that the current density of the fuel electrode with the FeCoNiCuRu high-entropy alloy loading is significantly higher than that of the GDC-LSM and FeCoNi@GDC-LSM composite electrodes in the temperature range of 700-850℃. Meanwhile, the polarization impedance of the FeCoNiCuRu@GDC-LSM|LSGM|PBSGF electrolyzer at 1.5V is also much lower than that of the GDC-LSM|LSGM|PBSGF electrolyzer (0.065 vs. 1.3 Ωcm). 2 ).

[0117] Figure 12 This presents the polarization impedance of FeCoNiCuRu@GDC-LSM|LSGM|PBSGF at 800℃ and different voltages, along with the corresponding DRT fitting results. The impedance results clearly show a trend of decreasing polarization impedance with increasing voltage. Further DRT analysis reveals that the high-frequency region (>10) related to electrolyte-electrode ion transport... 3 The frequency (Hz) does not change with voltage. However, the mid-to-low frequency range (less than 10 Hz) is highly correlated with CO2RR. 3 The peak intensity (Hz) decreases significantly with increasing voltage, indicating that voltage can greatly promote the catalytic conversion of CO2.

[0118] Figure 13is the DRT results of the impedance of GDC-LSM|LSGM|PBSGF and FeCoNiCuRu@GDC-LSM|LSGM|PBSGF two electrolytic cells at 800℃, 1.5V. It can be seen that the fuel electrode with FeCoNiCuRu high-entropy alloy load has very small peak response intensity in the low-frequency region, which means that the alloy has significantly improved CO2RR activity. FeCoNiCuRu@GDC-LSM is also an excellent solid oxide electrolytic cell fuel electrode candidate material.

[0119] Figure 14 is the SEM morphology of FeCoNiCuRu@GDC-LSM|LSGM|PBSGF after testing. It can be seen that the LSGM electrolyte thickness is about 250μm, and the FeCoNiCuRu@GDC-LSM fuel electrode thickness is about 20μm. The surface of the fuel electrode after testing is still distributed with uniform high-entropy alloy particles.

[0120] 7. Electrolytic cell Faraday efficiency test

[0121] Figure 15 is the CO production and Faraday efficiency of FeCoNiCuRu@GDC-LSM fuel electrode electrolysis of CO2 at 800℃ under different current densities; FeCoNiCuRu@GDC-LSM electrode at 800℃, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, 2.2 and 2.4A cm -2 , respectively, the CO production rate is 3.67, 5.09, 6.57, 8.01, 9.46, 10.91, 12.39, 13.84, 15.29 and 16.53mL cm -2 min -1 , the Faraday efficiency of FeCoNiCuRu@GDC-LSM fuel electrode in electrolysis of CO2 is higher than 95% when the current density is greater than 1.2A cm -2 , and reaches 99.81% at 2.2A cm -2 , indicating that FeCoNiCuRu@GDC-LSM electrode has excellent CO2RR activity and electrochemical reaction rate.

Claims

1. A high-entropy alloy nanoparticle supported perovskite oxide, characterized in that, The core material is a composite material of gadolinium-doped cerium dioxide and lanthanum strontium manganese calcium perovskite (GDC-LSM), and the alloy material is an alloy of iron, cobalt, nickel, copper and ruthenium.

2. The high entropy alloy nanoparticle supported perovskite oxide of claim 1, wherein, The gadolinium-doped ceria composite material with a chemical formula of Gd 0.2 Ce 0.8 O 1.95 -La 0.6 Sr 1.4 MnO 4+δ ; δ is the content of oxygen vacancies.

3. The high entropy alloy nanoparticle supported perovskite oxide of claim 1, wherein, The high-entropy alloy nanoparticles have a nanoscale particle size, and the weight of the alloy material is 1-5% of the weight of the core material.

4. The high entropy alloy nanoparticle supported perovskite oxide of claim 1, wherein, The alloy material has a chemical formula of Fe x Co y Ni z Cu m Ru n wherein x, y, z, m, n > 0 and x + y + z + m + n = 1.

5. The high entropy alloy nanoparticle supported perovskite oxide of claim 1, wherein, The alloy material x=y=z=m=n=0.2, the particle size is 100-300 nm, and the molar proportion of the Ru element in the alloy is 10%-30%.

6. The method of claim 1, wherein the perovskite oxide is prepared by the steps of: The method comprises the following steps: Step 1, dissolving Gd salt, Ce salt, La salt, Sr salt and Mn salt in water according to the stoichiometric ratio, adding a complexing agent and adjusting the pH, and then reacting to generate a gel; drying the gel and calcining to obtain GDC-LSM powder; Step 2, dissolving a certain amount of Fe salt, Co salt, Ni salt, Cu salt and Ru salt in water according to the selected stoichiometric ratio, adding the synthesized GDC-LSM powder, continuing to heat and stir until the water is evaporated, and then calcining and reducing to obtain the final electrode material.

7. The preparation method according to claim 6, characterized in that, In Step 1, the molar ratio of total metal ions: EDTA: CA: ammonia is 1: 0.5-1.5: 1-3: 3-20, the drying condition is 140-160℃ baking for 1-10h, the calcination temperature is 900-1200℃ calcination for 1-10h, and the heating rate is 2-8℃ / min.

8. The preparation method according to claim 6, characterized in that, In Step 2, the heating and stirring process to evaporate the water is carried out at 50-80℃ for 5-10h, the calcination temperature is 900-1200℃ calcination for 1-10h, and the heating rate is 2-8℃ / min. The reduction temperature is 800-1000℃ reduction for 5-20h, the atmosphere is 10% H2 / N2, and the heating rate is 2-8℃ / min.

9. Use of the perovskite oxide material of claim 1 in a solid oxide electrolysis cell or an oxygen ion conductor fuel electrode; the electrolysis cell is used for CO2 electrolysis to produce CO.

10. A method of increasing the amount of chemical adsorption of CO2 by a perovskite oxide loaded with the high-entropy alloy nanoparticles of claim 1, characterized in that, The perovskite oxide has a CO2 chemical adsorption capacity increased by 100-120% compared with GDC-LSM, and increased by 30-40% compared with GDC-LSM loaded with a ternary alloy of iron, cobalt and nickel on the surface.

Images