A mixed metal oxide supported catalyst, its preparation method and use

Abstract

This invention belongs to the field of electrocatalysis technology, specifically a mixed metal oxide supported catalyst, its preparation method, and its application. In this mixed metal oxide supported catalyst, the active component is selected from Ru, Ir, and Pt, and the support is a metal oxide ABOx formed by the homogeneous blending of metal oxides AOm and Bon; A and B are respectively selected from transition metal atoms or main group metal atoms; AOm... m The main support component contains at least two metal-oxygen coordination structures, and is associated with BO, the secondary support component. n A blending interface is formed, providing oxygen diffusion channels required for the oxygen evolution reaction (OER). B is used to regulate the electronic structure of the host support A, thereby regulating the electronic structure of the noble metal atoms, which helps improve the OER activity and stability of the catalyst. The catalyst of this invention can be used to prepare OER catalyst electrodes and water electrolysis devices. The preparation process of this invention is simple, and it can achieve high OER activity and stability while reducing the noble metal content, showing broad application prospects.

Description

Technical Field

[0001] This invention belongs to the field of electrochemical catalysis technology, specifically relating to mixed metal oxide supported catalysts, their preparation methods, and applications. Background Technology

[0002] Polymer electrolyte membrane (PEM, also known as proton exchange membrane) water electrolysis devices are a new type of water electrolysis device. Compared with alkaline water electrolysis devices, they have advantages such as high current density, high pure hydrogen concentration, high pressure, low gas permeation and fast dynamic response. They can fully adapt to the fluctuations of renewable energy power generation and have broad application prospects.

[0003] Water electrolysis consists of two half-reactions: the cathode hydrogen evolution reaction (HER) and the anode oxygen evolution reaction (OER). Compared to the cathode HER, the anode OER involves multiple electron transfer steps and has slower kinetics. Therefore, developing highly active anode catalysts is one of the key issues that need to be addressed to further improve the efficiency of water electrolysis. At the same time, the strong acid and strong oxidizing environment of PEM water electrolysis also places high demands on the stability of the anode catalyst.

[0004] Currently, noble metal oxides IrO2 and RuO2 are the most commonly used acidic OER catalysts, but their high price limits their application in PEM water electrolysis, and their activity and stability do not meet the requirements for industrial applications.

[0005] Therefore, there is an urgent need for a new type of mixed metal oxide supported catalyst whose activity and stability can meet the industrial requirements of PEM water electrolysis, while also reducing costs. Summary of the Invention

[0006] The first objective of this invention is to provide a mixed metal oxide supported catalyst and its preparation method, which has the activity and stability to meet the industrial requirements of PEM water electrolysis, while reducing catalyst cost.

[0007] Another objective of this invention is to provide an oxygen evolution reaction catalyst electrode and its preparation method, as well as a water electrolysis device, which uses a mixed metal oxide supported catalyst to improve the oxygen evolution reaction efficiency.

[0008] The mixed metal oxide supported catalyst provided by this invention includes a support component and an active component supported on the support component; the active component is a noble metal atom M, and the noble metal atom M is selected from at least one of Ru, Ir, and Pt; the support component is a mixed metal oxide ABO.x The mixed metal oxide ABO x AO metal oxide, which is stable in both acidic and oxidizing environments m and metal oxide BO n A homogeneous blend is formed, wherein metal atoms A and B are selected from transition metal atoms or main group metal atoms different from noble metal atoms M, and the sum of the contents of metal atoms A and B accounts for 50%-99% of the total contents of metal atoms A, B, and M; in the mixed metal oxide ABO x In the above, the metal oxide AO m The metal oxide BO serves as the main support component and contains at least two metal-oxygen coordination structures, and is used in conjunction with the metal oxide BO serving as the secondary support component. n A blending interface is formed, which provides the oxygen diffusion channel required for the oxygen evolution reaction. Metal atom B is used to regulate the electronic structure of the host carrier A, thereby regulating the electronic structure of the noble metal atom M. x O m and O n O represents oxygen atoms, the subscript indicates the oxygen atom ratio of the metal oxide, and x, m, and n are constants.

[0009] Further, it is preferred that the sum of the contents of metal atoms A and B accounts for 70%-99% of the total contents of metal atoms A, B, and M; more preferably, it is preferred that the sum of the contents of metal atoms A and B accounts for 85%-99% of the total contents of metal atoms A, B, and M.

[0010] Optionally, the metal atom A is selected from one of W, Mo, Pd, Ag, Mn, Pb, Sn, Sb, Zr, Ta, Nb, Co, and Ce, and the metal atom B is selected from one of W, Mo, Pd, Ag, Mn, Pb, Sn, Sb, Zr, Ta, Nb, Co, and Ce.

[0011] This invention also provides a method for preparing the mixed metal oxide supported catalyst, the specific steps of which are as follows:

[0012] (1) Weigh out two metal oxides AO that are stable in both acidic and oxidizing environments according to the preset ratio. m and BO n And uniformly dispersed in the corresponding organic solvent to obtain a precipitate;

[0013] (2) After drying the precipitate, it is calcined in a tube furnace to obtain a mixed metal oxide ABO. x ;

[0014] (3) Dissolve the noble metal salt in a polyol solvent according to the required ratio, and then add the mixed metal oxide ABO. xThe mixture is then agitated to disperse it evenly, thereby obtaining a mixture, wherein the noble metal atom M in the noble metal salt is selected from at least one of Ru, Ir, and Pt;

[0015] (4) Heat the mixture according to the preset conditions and filter to obtain the precipitate;

[0016] (5) The precipitate is washed with ethanol and water, and after drying, it is calcined in a tube furnace to obtain a mixed metal oxide supported catalyst, wherein the mixed metal oxide supported catalyst is based on the mixed metal oxide ABO x The carrier component is the noble metal atom M, which is the active component.

[0017] Optionally, the organic solvent in step (1) is selected from methanol, ethanol, isopropanol, acetone, and tetrahydrofuran.

[0018] Optionally, in step (2), the precipitate is dried and then calcined in a tube furnace using a hydrogen-argon mixed atmosphere. The heating rate is controlled at 1℃ / min-20℃ / min, and the temperature is raised to 200℃-1000℃ for 1-6 hours to obtain the mixed metal oxide ABO. x .

[0019] Optionally, the ratio described in step (3) includes: 0.5g-5g of ruthenium salt, iridium salt, or platinum salt, 50mL-200mL of polyol solvent, and 1g-20g of mixed metal oxide ABO. x .

[0020] Optionally, the noble metal M salt is selected from at least one of Ru salt, Ir salt, and platinum salt; the Ru salt is selected from at least one of anhydrous ruthenium chloride, hydrated ruthenium chloride, ruthenium chloride trihydrate, ruthenium acetylacetonate, and ruthenium nitrite; the Ir salt is selected from at least one of anhydrous iridium trichloride, iridium trichloride hydrate, iridium tetrachloride hydrate, iridium acetylacetonate, and sodium hexachloroacetate; and the Pt salt is selected from at least one of chloroplatinic acid hydrate, chloroplatinic acid hexahydrate, platinum hexahydroxide, sodium platinum hexahydroxide, platinum acetylacetonate, potassium hexachloroplatinate, ammonium hexachloroplatinate, potassium chloroplatinate, potassium chloroplatinate, ammonium chloroplatinate, potassium trichloroplatinate hydrate, and tetrabutylammonium hexachloroplatinate.

[0021] Optionally, the polyol solvent is one of ethylene glycol, glycerol, 1,2-propanediol, and pentaerythritol.

[0022] Optionally, the preset conditions in step (4) are: heating the mixture at 100℃-200℃ for 1h-5h.

[0023] Optionally, in step (5), the precipitated product is placed in a tube furnace for calcination, using an air atmosphere, and the heating rate is controlled at 1℃ / min-20℃ / min, heated to 200℃-800℃, and calcined for 1h-6h to obtain a mixed metal oxide supported catalyst.

[0024] This invention also provides a method for preparing an oxygen evolution reaction catalyst electrode, comprising:

[0025] (1) The mixed metal oxide supported catalyst, binder, and conductive agent are added to a mixed solvent of organic solvent and water to form a catalyst slurry;

[0026] (2) The catalyst slurry is ultrasonically dispersed and then coated onto a conductive substrate or a proton exchange membrane to form an oxygen evolution reaction catalyst electrode. Alternatively, the catalyst slurry is first sprayed onto a support film, dried, and then attached to a proton exchange membrane. The support film is then peeled off to obtain the oxygen evolution reaction catalyst electrode.

[0027] Optionally, the binder has a proportion of 1%-30% in the catalyst slurry, the conductive agent has a proportion of 10%-30% in the catalyst slurry, and the mixed metal oxide supported catalyst is loaded at 1 mg / cm³ on the oxygen evolution reaction catalyst electrode. 2 -50 mg / cm 2 .

[0028] Optionally, the organic solvent in the mixed solvent includes at least one of methanol, ethanol, isopropanol, tetrahydrofuran, and acetone; the binder is a perfluorosulfonic acid polymer solution; and the conductive agent includes at least one of carbon nanotubes, carbon black, and graphene.

[0029] Optionally, the conductive substrate includes carbon felt, carbon film, carbon cloth, metal foam or metal foil, the proton exchange membrane is a perfluorosulfonic acid resin film, and the carrier film is a polytetrafluoroethylene film.

[0030] The present invention also provides an oxygen evolution reaction catalyst electrode, which includes an electrode support and a mixed metal oxide supported catalyst as described in the present invention, covered on the electrode support. The electrode support is a conductive substrate or a proton exchange membrane. The conductive substrate is a carbon felt, a carbon film, a carbon cloth, a metal foam, or a metal foil. The proton exchange membrane is a perfluorosulfonic acid resin film. The support film is a polytetrafluoroethylene film.

[0031] The present invention also provides a water electrolysis device having a mixed metal oxide supported catalyst as described in the present invention as an anode catalyst; or, the water electrolysis device having an oxygen evolution reaction catalyst electrode as described in the present invention.

[0032] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0033] 1. In this invention, a noble metal atom M (selected from at least one of Ru, Ir, and Pt) or an oxide containing a noble metal atom M is loaded onto other mixed metal oxides ABO that are stable under acidic and oxidizing conditions. x The above (containing binary metal atoms A and B) can form a mixed metal oxide supported catalyst M-ABO. x The mixed metal oxide supported catalyst M-ABO x The main carrier component AO m It can provide a variety of metal-oxygen coordination structures, and with BO as a secondary support component n A blending interface is formed to provide oxygen diffusion channels required for the oxygen evolution reaction. Metal atom B can modulate the electronic structure of noble metal atoms M such as Ru, Ir, and Pt. Therefore, the mixed metal oxide supported catalyst M-ABO of this invention... x It changes the oxygen diffusion path in the oxygen evolution process, avoids the problems of easy peroxidation and reconstruction of existing unit metal oxide supports, and helps to improve the oxygen evolution activity and long-term stability of the catalyst.

[0034] 2. While maintaining catalyst activity, the content of noble metal atoms M is greatly reduced, thereby reducing catalyst cost;

[0035] 3. The preparation process of the mixed metal oxide supported catalyst and oxygen evolution reaction catalyst electrode of the present invention is simple and low in cost. It can realize the high activity and high stability of water electrolysis oxygen evolution reaction and has broad application prospects. Attached Figure Description

[0036] Figure 1 The M-ABO catalyst, a hybrid metal oxide supported catalyst according to a specific embodiment of the present invention, is... x A schematic diagram of a transmission electron microscope image.

[0037] Figure 2 This is a specific embodiment of the mixed metal oxide supported catalyst Ir-ZrTaO. x The energy spectrum distribution diagram.

[0038] Figure 3 This is a specific embodiment of the mixed metal oxide supported catalyst Ir-ZrTaO. x Comparison diagram with the X-ray diffraction patterns of the corresponding ZrO2 and Ta2O5 materials.

[0039] Figure 4 This is a specific embodiment of the mixed metal oxide supported catalyst Ir-ZrTaO. x Its corresponding IrO2 and Ir-ZrOx Ir-TaO x The linear voltammetric curves of ZrO2 and Ta2O5 materials are shown in the comparison figure. The scan rate of the linear scan voltammetry test for each material is 5 mV / s.

[0040] Figure 5 This is a specific embodiment of the mixed metal oxide supported catalyst Ir-ZrTaO. x The potential curve of the constant current test over 1000 hours, with a test current density of 10 mA / cm². 2 .

[0041] Figure 6 This is a specific embodiment of the mixed metal oxide supported catalyst Ir-ZrTaO. x Its corresponding Ir-ZrO x Ir-TaO x A comparison of the potential curves for the material's stability test over 200 hours, with a current density of 10 mA / cm² used in all tests. 2 .

[0042] Figure 7 This is a specific embodiment of the mixed metal oxide supported catalyst Ir-ZrTaO. x A schematic diagram of the voltage curve used as the anode catalyst in a proton exchange membrane water electrolysis device, and its stability tested in constant current mode. The current density used in this test was 1 A / cm². 2 .

[0043] Figure 8 This is a flowchart illustrating the preparation method of a mixed metal oxide supported catalyst according to a specific embodiment of the present invention.

[0044] Figure 9 This is a flowchart illustrating the preparation method of the oxygen evolution reaction catalyst electrode according to a specific embodiment of the present invention. Detailed Implementation

[0045] The core of the technical solution of this invention is that, based on existing single-unit metal oxide AO... m or BO n In supported Ru-based or Ir-based catalysts, a second metal oxide support (BO) is introduced. n or AO m Constructing a hybrid metal oxide ABO x Supported catalyst M-ABO xIt can change the oxygen diffusion path in the oxygen evolution reaction and regulate the electronic structure of noble metal atoms M (i.e., at least one of Ru, Ir, and Pt), ultimately achieving high activity and long-term stability of the catalyst. At the same time, it can reduce the content of noble metal atoms M, thereby reducing costs and improving water electrolysis efficiency. This allows the catalyst to meet the stability and activity requirements of the strong acid and strong oxidation environment of PEM water electrolysis.

[0046] The technical solution proposed by the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings. It should be noted that the accompanying drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the purpose of illustrating the embodiments of the present invention.

[0047] Please refer to Figure 1 One embodiment of the present invention provides a mixed metal oxide supported catalyst, the material of which is abbreviated as M-ABO. x Specifically, it includes a carrier component and an active component, wherein the carrier component is a mixed metal oxide ABO that is stable under strong acid and strong oxidation conditions. x The active component is a noble metal atom M.

[0048] Wherein, the noble metal atom M is selected from at least one of Ru, Ir, and Pt, thus the M-ABO of this embodiment is... x In fact, it is also a supported Ru-based, Ir-based, or Pt-based catalyst, or a supported catalyst that is a blend of supported Ru-based, Ir-based, and supported Pt-based catalysts.

[0049] Mixed metal oxides ABO x It consists of two different metal oxides AO m and metal oxide BO n Formed by homogeneous dispersion of blended metal oxides AO m and metal oxide BO n It is stable under strong acid and strong oxidizing conditions (such as the acidic conditions of water electrolysis). Metal atoms A and B are two different metal atoms selected from transition metal atoms or main group metal atoms that are different from the noble metal atom M.

[0050] In the mixed metal oxide ABO x In the middle, metal oxide AO m As the main carrier component, metal oxide BO n As a secondary support component, metal oxide AO m It can provide at least two metal-oxygen coordination structures, and with metal oxide BO n A blending interface is formed, which provides the oxygen diffusion channels (i.e., oxygen diffusion paths) required for the oxygen evolution reaction. The metal oxide BO nMetal atom B in the matrix can regulate the electronic structure of the host carrier A, thereby regulating the electronic structure of the noble metal atom M.

[0051] It should be understood that the metal oxides AOm and BON can be any two suitable metal oxides that meet the above conditions. For example, metal atom A is selected from one of W, Mo, Pd, Ag, Mn, Pb, Sn, Sb, Zr, Ta, Nb, Co, and Ce, and metal atom B is selected from one of W, Mo, Pd, Ag, Mn, Pb, Sn, Sb, Zr, Ta, Nb, Co, and Ce.

[0052] As an example, metal oxide AO m For tantalum oxide, the metal-oxygen coordination structures it can provide include TaO7, TaO6, TaO5, TaO4, etc. Metal oxide BO n The catalyst is ZrO2. The noble metal atom M is Ir, and the catalyst is a mixed metal oxide supported catalyst M-ABO. x For Ir-ZrTaO x .

[0053] In this embodiment, the sum of the total content of metal atoms A, B, and M is considered to be 100%, then the content of noble metal atom M is 1%-50% (that is, the sum of the total content of Ru, Ir, and Pt is 1%-50%), and the sum of the total content of metal atoms A and B is 50%-99%.

[0054] The following example uses the mixed metal oxide supported catalyst M-ABO from this embodiment. x For Ir-ZrTaO x Taking this example, we will analyze and explain in detail the performance of the mixed metal oxide supported catalyst in this embodiment.

[0055] Figure 1 It is a mixed metal oxide supported catalyst Ir-ZrTaO x A schematic diagram of a transmission electron microscope image. Figure 2 It is a mixed metal oxide supported catalyst Ir-ZrTaO x Energy spectrum distribution of the material. From the bonding... Figure 1 and Figure 2 As can be seen from this, the mixed metal oxide supported catalyst Ir-ZrTaO x In the mixture, Ta₂O₅ and ZrO₂ are particles of approximately 200 nm, while Ir atoms are successfully loaded onto the mixed metal oxide ZrTaO₅. x On the carrier (i.e. loaded onto Ta2O5 and ZrO2).

[0056] Figure 3 It is a mixed metal oxide supported catalyst Ir-ZrTaO xX-ray diffraction patterns of materials, including ZrO2 and Ta2O5. From... Figure 3 As can be seen from this, the mixed metal oxide supported catalyst Ir-ZrTaO x The X-ray diffraction characteristic peaks of the material are mainly attributed to its support β-Ta₂O₅, while Ir and Zr show no obvious characteristic peaks due to their low content. This indicates that the mixed metal oxide ZrTaO₅... x In this process, Ta2O5 is the main carrier component, ZrO2 is the secondary carrier component, and Ir content is low or particle size is small and crystallinity is not high.

[0057] Figure 4 It is a mixed metal oxide supported catalyst Ir-ZrTaO x Materials and IrO2, Ir-ZrO x Ir-TaO x Comparison of linear sweep voltammetry (LSV) curves of ZrO2 and Ta2O5 materials used to form OER catalyst electrodes. The scan rate for the linear sweep voltammetry test of each material was 5 mV / s, and the loading of these catalyst materials for the OER catalyst electrode was 22.5 μg cm⁻¹. -2 .from Figure 4 As can be seen from this, the mixed metal oxide supported catalyst Ir-ZrTaO x Under catalysis, it reaches 10 mA / cm 2 The potential of the oxygen evolution reaction current is 1.48V, which is significantly better than that of IrO2 and Ir-ZrO. x Ir-TaO x Catalysts such as ZrO2, Ta2O5, and commercial IrO2 catalysts.

[0058] Figure 5 It is a mixed metal oxide supported catalyst Ir-ZrTaO x Potential curves of the material under constant current testing for 1000 hours (h) in a laboratory with three electrodes. Figure 6 It is a mixed metal oxide supported catalyst Ir-ZrTaO x Materials and Ir-ZrO x Ir-TaO x The potential curves of the material stability test over 200 hours are compared, and the current density used in the test was 10 mA / cm². 2 .from Figure 5 As can be seen from the data, during the 1000-hour constant current test, the mixed metal oxide supported catalyst Ir-ZrTaO... x The material potential did not show a significant increase, indicating that the mixed metal oxide supported catalyst Ir-ZrTaO xThe material exhibits extremely high stability. From Figure 6 As can be seen from the data, during the 200-hour constant current test, the mixed metal oxide supported catalyst Ir-ZrTaO... x The change in material potential relative to Ir-ZrO x Ir-TaO x The material is relatively small, which indicates that the mixed metal oxide supported catalyst Ir-ZrTaO x Material relative to single-metal oxide supported catalysts Ir-ZrO x Ir-TaO x The material has extremely high stability.

[0059] Figure 7 It is a mixed metal oxide supported catalyst Ir-ZrTaO x A schematic diagram of the voltage curve used as the anode catalyst in a proton exchange membrane water electrolysis device, and its stability tested in constant current mode, is shown, where the test current density is 1 A / cm². 2 The temperature is 80℃. From Figure 7 As can be seen from this, the mixed metal oxide supported catalyst Ir-ZrTaO x No significant voltage increase was observed during the constant current test under operating conditions over 240 hours, indicating that the Ir-ZrTaO mixed metal oxide supported catalyst... x Electrolyzed water still exhibits high stability under operating conditions.

[0060] In summary, the Ir-ZrTaO mixed metal oxide supported catalyst of this embodiment is effective. x It can change the oxygen diffusion path in the oxygen evolution process, avoid the problems of easy peroxidation and reconstruction of existing unit metal oxide supports, and help improve the oxygen evolution activity and long-term stability of the catalyst.

[0061] Please refer to Figure 8 This embodiment also provides a method for preparing a mixed metal oxide supported catalyst, which includes the following steps:

[0062] S1.1, Weigh out two metal oxides AO that are stable in both acidic and oxidizing environments according to a preset ratio. m and BO n The precipitate is uniformly dispersed in organic solvents such as methanol, ethanol, isopropanol, acetone or tetrahydrofuran to obtain a suspension containing precipitate. The suspension is then treated by centrifugation or filtration to obtain the precipitate.

[0063] S1.2, the precipitate is dried and then calcined in a tube furnace (e.g., in a hydrogen-argon mixed atmosphere, heated to 200℃-1000℃ at a heating rate of 1℃ / min-20℃ / min, calcined for 1h-6h) to obtain the mixed metal oxide ABO. x .

[0064] S1.3, prepare according to the required ratio (e.g., 0.5g-5g ruthenium salt, iridium salt, or platinum salt, 50mL-200mL polyol solvent, and 1g-20g mixed metal oxide ABO). x The noble metal salt is dissolved in a polyol solvent selected from ethylene glycol, glycerol, 1,2-propanediol, and pentaerythritol, and then a mixed metal oxide, ABO, is added. x The mixture is then agitated to disperse it evenly, resulting in a mixed solution. The noble metal atom M in the noble metal salt is selected from at least one of Ru, Ir, and Pt, specifically, the noble metal salt is selected from at least one of Ru salt, Ir salt, and Pt salt. The Ru salt is selected from at least one of anhydrous ruthenium chloride, hydrated ruthenium chloride, ruthenium chloride trihydrate, ruthenium acetylacetonate, and ruthenium nitrite. The Ir salt is selected from at least one of anhydrous iridium trichloride, iridium trichloride hydrate, iridium tetrachloride hydrate, iridium acetylacetonate, and sodium hexachloroacetate. The Pt salt is selected from at least one of chloroplatinic acid hydrate, chloroplatinic acid hexahydrate, platinum hexahydroxide, sodium platinum hexahydroxide, platinum acetylacetonate, potassium hexachloroplatinate, ammonium hexachloroplatinate, potassium chloroplatinate, potassium chloroplatinate, ammonium chloroplatinate, potassium trichloroplatinate hydrate, and tetrabutylammonium hexachloroplatinate.

[0065] S1.4, the mixture is heated according to preset conditions (e.g., heated at 100℃-200℃ for 1h-5h) and filtered to obtain the precipitated product.

[0066] S1.5, the precipitate is washed with ethanol and water, and after drying, it is calcined in a tube furnace (e.g., heated to 200°C-800°C in air at a heating rate of 1°C / min-20°C / min, and calcined for 1-6 hours) to obtain a mixed metal oxide supported catalyst, wherein the mixed metal oxide supported catalyst is based on the mixed metal oxide ABO x The carrier component is the noble metal atom M, which is the active component.

[0067] The mixed metal oxide supported catalyst provided in this embodiment can be used to manufacture oxygen evolution reaction catalyst electrodes or as an anode catalyst in a proton exchange membrane-based water electrolysis device.

[0068] Based on this, please refer to Figure 9 This embodiment also provides a method for preparing an oxygen evolution reaction catalyst electrode, which includes the following steps:

[0069] S2.1, Provide a mixed metal oxide supported catalyst as described in this embodiment, or prepare a mixed metal oxide supported catalyst using the preparation method of the mixed metal oxide supported catalyst as described in this embodiment.

[0070] S2.2, the mixed metal oxide supported catalyst of this embodiment, a binder (e.g., a perfluorosulfonic acid polymer solution), and a conductive agent (which may include at least one of carbon nanotubes, carbon black, and graphene) are added to a mixed solvent of organic solvents such as methanol, ethanol, isopropanol, tetrahydrofuran, or acetone and water to form a catalyst slurry; wherein, optionally, the binder has a proportion of 1%-30% in the catalyst slurry, and the conductive agent has a proportion of 10%-30% in the catalyst slurry.

[0071] S2.3 After ultrasonically dispersing the catalyst slurry, it is coated onto a conductive substrate (e.g., a 50μm-250μm conductive carbon film) such as carbon felt, carbon film, carbon cloth, metal foam, or metal foil to form an oxygen evolution reaction catalyst electrode. Alternatively, it is coated onto a proton exchange membrane (which can be made of perfluorosulfonic acid resin) with a thickness of 10μm-250μm to form a proton exchange membrane anode supported by the mixed metal oxide-supported catalyst of this embodiment. Alternatively, the catalyst slurry is first sprayed onto a support film (e.g., a 10μm-250μm thick polytetrafluoroethylene film), dried, and then hot-pressed at 100℃-260℃ and 1MPa-20MPa for 1min-20min. After holding the pressure, the support film is carefully peeled off to obtain a proton exchange membrane anode supported by the mixed metal oxide-supported catalyst of this embodiment. The loading of the mixed metal oxide-supported catalyst on the oxygen evolution reaction catalyst electrode in this embodiment is 1mg / cm³. 2 -50 mg / cm 2 The adhesive comprises 5-40% by mass.

[0072] The preparation method of the mixed metal oxide supported catalyst and the preparation method of the oxygen evolution reaction catalyst electrode in this embodiment will be described in detail below with specific examples.

[0073] First Example

[0074] (1) Please combine Figure 8 Preparation of a mixed metal oxide supported catalyst based on polyol reduction: Step S1.1, 0.5 g of zirconium oxide (ZrO2) and 2 g of tantalum oxide (Ta2O5) were weighed into 50 mL of ethanol, ultrasonically dispersed for 30 min to form a uniformly dispersed suspension, and then centrifuged to obtain a precipitate; Step S1.2, after the precipitate was dried, it was placed in a tube furnace and annealed at 600 °C for 4 h (i.e., calcined), and cooled to room temperature to obtain the mixed metal oxide Zr1Ta10 O x Step S1.3: Add 100 mg of the mixed metal oxide Zr1Ta 10 O x Disperse the sodium hexachloroiridate into 12.8 mL of ethylene glycol, then add 7.2 mL of ethylene glycol solution containing sodium hexachloroiridate (Na3IrCl6) to form a mixture with a sodium hexachloroiridate concentration of 3.48 g. Ir / L. Step S1.4: Place the mixed solution in an oil bath and heat at 160℃ for 2.5h with continuous stirring. After cooling to room temperature, filter to obtain the precipitate. Step S1.5: Wash the precipitate with ethanol and water to obtain the mixed metal oxide supported catalyst Ir-ZrTaO. x Material.

[0075] (2) Please combine Figure 9 A type of Ir-ZrTaO x Preparation of the supported catalyst electrode: Step S2.2, 5 mg of mixed metal oxide supported catalyst Ir-ZrTaO was added. x 2 mg of carbon powder and 20 μL of 5 wt% perfluorosulfonic acid resin monomer solution were added to 1 mL of a mixed solvent of ethanol and water, wherein the volume ratio of ethanol to water was 5:1. After ultrasonic dispersion, a catalyst slurry was formed. In step S2.3, the catalyst slurry was drop-coated onto an area of ​​0.0706 cm². -2 On a glassy carbon electrode, after drying, an OER catalyst electrode, Ir-ZrTaO, is obtained. x The loading capacity was 22.5 μg cm. -2 The OER catalyst electrode was subjected to linear voltammetry scanning in a 0.5 mol H₂SO₄ aqueous solution, and its LSV curve was obtained, as shown below. Figure 4 As shown, it reaches 10 mA / cm 2 The potential of the oxygen evolution reaction current is 1.48 V, indicating that the OER catalyst electrode is significantly superior to commercial RuO2 and IrO2 catalyst electrodes. Figure 5 As shown, during the 1000-hour constant current test, the potential of the OER catalyst electrode did not show a significant increase, indicating that the OER catalyst electrode has extremely high stability.

[0076] Second example

[0077] (1) Please combine Figure 8Preparation of a supported catalyst material based on a polyol reduction method using a mixed metal oxide as a support: Step S1.1, 20.5 mg of zirconium oxide (ZrO2) and 368.2 mg of tantalum oxide (Ta2O5) were weighed into 50 mL of ethanol, ultrasonically dispersed for 30 min to form a uniformly dispersed suspension, and then centrifuged to obtain a precipitate; Step S1.2, after the precipitate was dried, it was placed in a tube furnace and annealed at 600 °C for 2 h, and cooled to room temperature to obtain the mixed metal oxide Zr1Ta 10 O x Step S1.3: Add 100 mg of the mixed metal oxide Zr1Ta 10 O x The solution was dispersed in 12.8 mL of ethylene glycol, and then 7.2 mL of an ethylene glycol solution of sodium hexachloroiridate (Na3IrCl6) was added to obtain a mixed solution with a sodium hexachloroiridate concentration of 3.48 g. Ir / L. Step S1.4: Place the mixed solution in an oil bath and heat at 160℃ for 2.5h with continuous stirring. After cooling to room temperature, filter to obtain the precipitate; Step S1.5: Wash the precipitate with ethanol and water to obtain the mixed metal oxide supported catalyst Ir-ZrTaO. x .

[0078] (2) Please combine Figure 9 A supported catalyst based on a mixed metal oxide support is used for the preparation of the anode electrode of a proton exchange membrane water electrolysis: Step S2.2, the above-obtained mixed metal oxide supported catalyst Ir-ZrTaO is used. x The material was used as the anode catalyst. 20 mg of the mixed metal oxide supported catalyst Ir-ZrTaO was weighed out. x The material was dispersed in 10 mL of isopropanol, and 120 μL of a 5 wt% perfluorosulfonic acid resin monomer solution was added. After ultrasonication to ensure uniform dispersion, a catalyst slurry was obtained. In step S2.3, the catalyst slurry was sprayed onto a 5 cm² area. 2 of On a type 117 proton exchange membrane, the anolyte Ir loading is approximately 0.57 mg. Ir / cm 2 After drying, a mixed metal oxide-supported catalyst, Ir-ZrTaO, was obtained. x The proton exchange membrane anode.

[0079] (3) Based on the above, there is a mixed metal oxide supported catalyst Ir-ZrTaO x Assembly of a water electrolysis device with a proton exchange membrane anode.

[0080] First, weigh 5 mg of platinum-carbon catalyst with a platinum content of 40% and disperse it in 10 mL of a mixed solution of methanol and water (methanol:water = 9:1). At the same time, add 30 μL of 5 wt% perfluorosulfonic acid resin monomer solution and ultrasonically disperse it evenly to obtain another catalyst slurry.

[0081] Next, the other catalyst slurry was sprayed onto the area that had already been sprayed, which had a surface area of ​​5 cm². 2 anode catalyst The back side of the 117-type proton exchange membrane, with a platinum-carbon catalyst supported on the back side of the membrane containing approximately 0.1 mg of platinum. Pt / cm 2 .

[0082] After drying the proton exchange membrane, anode catalysts (i.e., mixed metal oxide supported catalysts Ir-ZrTaO) were obtained on both sides. x The proton exchange membrane of the cathode catalyst (platinum-carbon catalyst) and the cathode catalyst (platinum-carbon catalyst).

[0083] Next, the proton exchange membrane was hot-pressed at 60°C and 2MPa for 10 minutes to obtain a membrane electrode assembly for a proton exchange membrane water electrolysis device.

[0084] Subsequently, sealing rings and porous sintered titanium felt (5 cm² area) were respectively assembled on both sides of the membrane electrode assembly prepared above. 2 ), a titanium bipolar plate with an S-shaped flow channel (5cm²) 2 The proton exchange membrane water electrolysis device was assembled.

[0085] Deionized water at 80°C was introduced into the anode side of the proton exchange membrane water electrolysis device, and electrochemical tests were conducted. For example... Figure 7 As shown, the mixed metal oxide supported catalyst Ir-ZrTaO x No significant voltage increase was observed during the constant current test over 240 hours, indicating that the Ir-ZrTaO mixed metal oxide supported catalyst... x It still exhibits high stability under water electrolysis conditions.

[0086] It should be understood that the above two examples are merely illustrative examples of this embodiment and do not imply that the technical solution of the present invention is limited to these.

[0087] For example, in other examples of the present invention, when the prepared mixed metal oxide supported catalyst material is used as the anode catalyst in a proton exchange membrane-based water electrolysis device, and a platinum-carbon catalyst is used as the cathode catalyst, the platinum content of the cathode catalyst can be 20%-100%; when a perfluorosulfonic acid resin proton exchange membrane is used as the diaphragm, its thickness can be 25μm-250μm. Furthermore, sealing rings can be assembled on both sides of the membrane electrode assembly prepared above, and porous sintered titanium felt or carbon paper with a microporous layer can be used as the gas diffusion layer for the anode and cathode. A graphite plate, stainless steel plate, or titanium plate with engraved flow channels can be used as the bipolar plates for the anode and cathode, and a 0.05mol / -2mol / L sulfuric acid solution or pure water can be used as the electrolyte for the water electrolysis device, thus assembling a proton exchange membrane water electrolysis device.

[0088] For example, in other embodiments of the present invention, when using the mixed metal oxide supported catalyst material prepared according to the present invention to manufacture the membrane electrode assembly in a water electrolysis device based on a proton exchange membrane, the following steps can be taken: The mixed metal oxide supported catalyst material is dispersed in a mixed solvent of organic solvent and water, a binder is added, and the mixture is ultrasonically dispersed until uniform. The catalyst slurry is then sprayed onto a proton exchange membrane with a thickness of 10-250 μm. Alternatively, the catalyst slurry is sprayed onto a polytetrafluoroethylene (PTFE) film with a thickness of 10-250 μm, dried, and then bonded to the proton exchange membrane. The film is then hot-pressed at 100-260°C and 1-20 MPa for 1-20 min, and after holding the pressure, the PTFE film is carefully peeled off to obtain a proton exchange membrane anode with catalyst loading. The catalyst loading is 0.25 mg / cm³. 2 The adhesive comprises 5-40% by mass.

[0089] The catalyst preparation process and electrode preparation process of this embodiment are simple. They can reduce the noble metal content in the catalyst while achieving high oxygen evolution activity and stability of the catalytic junction, and have broad application prospects.

[0090] Based on the above examples, this embodiment also provides an oxygen evolution reaction (OER) catalyst electrode and a water electrolysis device. The OER catalyst electrode includes an electrode support and a mixed metal oxide supported catalyst, as described in this embodiment, covering the electrode support. The electrode support is a conductive substrate or a proton exchange membrane. The conductive substrate is carbon felt, carbon film, carbon cloth, metal foam, or metal foil. The proton exchange membrane is a perfluorosulfonic acid resin film, and the support film is a polytetrafluoroethylene film. The water electrolysis device has either the mixed metal oxide supported catalyst as described in this embodiment as the anode catalyst, or it has the OER catalyst electrode as described in this embodiment.

[0091] In summary, the M-ABO mixed metal oxide supported catalyst of this invention... xThe binary metal oxide support alters the oxygen diffusion pathway during the oxygen evolution process, avoiding the problems of easy peroxidation and reconstruction of single metal oxide supports, thus contributing to improved oxygen evolution activity and stability of the catalyst. Furthermore, the preparation process of this mixed metal oxide supported catalyst is simple, achieving high oxygen evolution activity and stability while reducing the precious metal content, and it has broad application prospects.

[0092] The above description is only a description of preferred embodiments of the present invention and is not intended to limit the scope of the present invention in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the present invention.

Claims

1. A mixed metal oxide supported catalyst, characterized in that, The composition includes a support component and an active component, wherein the active component is a noble metal atom M, and the noble metal atom M is selected from at least one of Ru, Ir, and Pt, and the support component is a mixed metal oxide ABO. x The mixed metal oxide ABO x AO metal oxide, which is stable in both acidic and oxidizing environments m and metal oxide BO n The mixture forms a homogeneous phase, with the sum of the contents of metal atoms A and B accounting for 50%-99% of the total contents of metal atoms A, B, and M. In the mixed metal oxide ABO x In the above, the metal oxide AO m The metal oxide BO serves as the main support component and contains at least two metal-oxygen coordination structures, and is used in conjunction with the metal oxide BO serving as the secondary support component. n A blending interface is formed, which provides an oxygen diffusion channel required for the oxygen evolution reaction. Metal atom B is used to regulate the electronic structure of the host carrier A, thereby regulating the electronic structure of the noble metal atom M. Among them, metal atom A is Zr and metal atom B is Ta; The homogeneous blend is formed through the following steps: (1) Weigh out two metal oxides AO that are stable in both acidic and oxidizing environments according to the preset ratio. m and BO n And uniformly dispersed in the corresponding organic solvent to obtain a precipitate; (2) After drying the precipitate, it is placed in a tube furnace for calcination to obtain a mixed metal oxide ABOx.

2. A method for preparing a mixed metal oxide supported catalyst as described in claim 1, characterized in that, The specific steps are as follows: (1) Weigh out two metal oxides AO that are stable in both acidic and oxidizing environments according to the preset ratio. m and BO n And uniformly dispersed in the corresponding organic solvent to obtain a precipitate; wherein, metal atom A is Zr and metal atom B is Ta; (2) The precipitate is dried and then calcined in a tube furnace to obtain a mixed metal oxide ABOx; (3) Dissolve the noble metal salt in a polyol solvent according to the ratio, and then add the mixed metal oxide ABO. x The mixture is then agitated to disperse it evenly, thereby obtaining a mixture, wherein the noble metal atom M in the noble metal salt is selected from at least one of Ru, Ir, and Pt; (4) Heat the mixture according to the preset conditions and filter to obtain the precipitate; (5) The precipitate is washed with ethanol and water, and after drying, it is calcined in a tube furnace to obtain a mixed metal oxide supported catalyst, wherein the mixed metal oxide supported catalyst is based on the mixed metal oxide ABO x The carrier component is the noble metal atom M, which is the active component.

3. The preparation method according to claim 2, characterized in that: The organic solvent mentioned in step (1) is selected from methanol, ethanol, isopropanol, acetone or tetrahydrofuran; In step (2), the precipitate is dried and then calcined in a tube furnace using a hydrogen-argon mixed atmosphere. The heating rate is controlled at 1 ℃ / min-20 ℃ / min, and the temperature is raised to 200℃-1000℃. The calcination is carried out for 1 h-6 h to obtain the mixed metal oxide ABO. x .

4. The preparation method according to claim 2, characterized in that, The ratio described in step (3) includes: 0.5 g-5 g of ruthenium salt, iridium salt, or platinum salt, 50 mL-200 mL of polyol solvent, and 1 g-20 g of mixed metal oxide ABO. x ; The precious metal salt is selected from at least one of Ru salt, Ir salt, and platinum salt; the Ru salt is selected from at least one of anhydrous ruthenium chloride, hydrated ruthenium chloride, ruthenium chloride trihydrate, ruthenium acetylacetonate, and ruthenium nitrite; the Ir salt is selected from at least one of anhydrous iridium trichloride, iridium trichloride hydrate, iridium tetrachloride hydrate, iridium acetylacetonate, and sodium hexachloroiridate; and the Pt salt is selected from at least one of chloroplatinic acid hydrate, chloroplatinic acid hexahydrate, platinum hexahydroxide, sodium platinum hexahydroxide, platinum acetylacetonate, potassium hexachloroplatinate, ammonium hexachloroplatinate, potassium chloroplatinate, potassium chloroplatinate, ammonium chloroplatinate, potassium trichloroplatinate hydrate, and tetrabutylammonium hexachloroplatinate. The polyol solvent is one of ethylene glycol, glycerol, 1,2-propanediol, and pentaerythritol.

5. The preparation method according to claim 2, characterized in that: The preset conditions in step (4) are: heating temperature of 100℃-200℃ and heating time of 1 h-5 h; In step (5), the precipitated product is placed in a tube furnace for calcination. An air atmosphere is used, and the heating rate is controlled at 1 ℃ / min-20 ℃ / min. The temperature is raised to 200℃-800℃ and calcined for 1 h-6 h to obtain a mixed metal oxide supported catalyst.

6. An oxygen evolution reaction catalyst electrode supported on a mixed metal oxide supported catalyst as described in claim 1, characterized in that, The device includes an electrode support and a mixed metal oxide supported catalyst covering the electrode support. The electrode support is a conductive substrate, a proton exchange membrane, or a support film. The conductive substrate is a carbon felt, a carbon film, a carbon cloth, a metal foam, or a metal foil. The proton exchange membrane is a perfluorosulfonic acid resin film, and the support film is a polytetrafluoroethylene film.

7. A method for preparing the oxygen evolution reaction catalyst electrode as described in claim 6, characterized in that, The specific steps are as follows: (1) The mixed metal oxide supported catalyst, binder, and conductive agent are added to a mixed solvent of organic solvent and water to form a catalyst slurry; (2) The catalyst slurry is ultrasonically dispersed and then coated onto a conductive substrate or a proton exchange membrane to form an oxygen evolution reaction catalyst electrode. Alternatively, the catalyst slurry is first sprayed onto a support film, dried, and then attached to a proton exchange membrane. The support film is then peeled off to obtain the oxygen evolution reaction catalyst electrode.

8. The preparation method according to claim 7, characterized in that, The binder comprises 1%-30% of the catalyst slurry, the conductive agent comprises 10%-30% of the catalyst slurry, and the mixed metal oxide supported catalyst is loaded at 1 mg / cm³ onto the oxygen evolution reaction catalyst electrode. 2 -50 mg / cm 2 ; The organic solvent in the mixed solvent is selected from at least one of methanol, ethanol, isopropanol, tetrahydrofuran, and acetone; the binder is a perfluorosulfonic acid polymer solution; and the conductive agent is selected from at least one of carbon nanotubes, carbon black, and graphene.

9. A water electrolysis device, characterized in that, The mixed metal oxide supported catalyst of claim 1 is used as the anode catalyst; or, it has the oxygen evolution reaction catalyst electrode of claim 6.

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