Monolithic tungsten-doped ruthenium dioxide catalyst as well as preparation method and application thereof

Abstract

The invention relates to the technical field of water electrolysis hydrogen production catalysts, in particular to an integral tungsten-doped ruthenium dioxide catalyst and a preparation method and application thereof.The preparation method comprises the steps that tungstic acid and ruthenium trichloride serve as raw materials and are dissolved in different solvents to prepare precursor solutions, then the precursor solutions are mixed to be uniform, and the integral tungsten-doped ruthenium dioxide catalyst is obtained; and dipping and coating a current collector, and carrying out drying and heating treatment to obtain the integral tungsten-doped ruthenium dioxide catalyst. The tungsten element is uniformly doped on the surface of ruthenium dioxide, so that the catalytic activity and the catalytic stability of the catalyst are greatly improved. And the tungsten-doped ruthenium dioxide catalyst is loaded on the current collector in the form of nano-scale particles, so that more active sites can be exposed, and the catalytic activity and the catalytic stability of the catalyst are further improved. The catalyst can be directly used as a working electrode, the preparation process is simplified, the preparation cost of the anode is saved, and the catalyst has a good application prospect in oxygen evolution reaction in hydrogen production through acidic water decomposition.

Description

Technical Field

[0001] The present invention relates to the technical field of catalysts for hydrogen production by electrolysis of water, and in particular to a monolithic tungsten-doped ruthenium dioxide catalyst, a preparation method thereof, and applications thereof. Background Art

[0002] As a clean energy source, hydrogen has the advantages of high calorific value and renewability. The product of hydrogen combustion is water that is pollution-free to the environment, which can greatly reduce the environmental burden. At present, hydrogen production using proton exchange membrane water electrolyzer is a very promising strategy. However, the proton exchange membrane will make the anode side locally acidic (pH ≈ 2). In an acidic environment, the kinetic process of the oxygen evolution reaction (OER) is very slow, which greatly limits the industrial application of proton exchange membrane water electrolysis technology (PEMWE). Therefore, there is an urgent need to develop acid-resistant catalysts with high OER activity.

[0003] At present, iridium-based catalysts are the main catalysts on the anode side of PEMWE, but their high cost and scarcity limit their large-scale industrial application. Ruthenium dioxide-based catalysts have high oxygen evolution catalytic activity and good stability in alkaline electrolyzed water, but poor stability in acidic water. In addition, the precursor of ruthenium dioxide is usually ruthenium hydroxide, which can be prepared by chemical precipitation. However, the disadvantage of this method is that the utilization rate of ruthenium is low, some ruthenium will be washed away during the preparation process, and a large amount of alkaline waste liquid is generated during the production process; moreover, the prepared ruthenium dioxide powder needs to be loaded onto the current collector or proton exchange membrane through another coating step, which increases the production process, and a large amount of loss is easily generated during the loading process, resulting in increased production costs. Therefore, it is very necessary to find a ruthenium dioxide-based catalyst with high activity, high stability and economical synthesis process. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the first object of the present invention is to provide a method for preparing an integral tungsten-doped ruthenium dioxide catalyst, which has the advantages of high ruthenium utilization, no waste liquid generation, simple process, and saving anode preparation cost. The prepared integral tungsten-doped ruthenium dioxide catalyst has the advantages of high oxygen evolution catalytic activity, excellent catalytic stability, and acid resistance.

[0005] In order to overcome the shortcomings of the prior art, the second object of the present invention is to provide an integral tungsten-doped ruthenium dioxide catalyst, which has the advantages of high oxygen evolution catalytic activity, excellent catalytic stability, and acid resistance.

[0006] The third object of the present invention is to provide an application of an integral tungsten-doped ruthenium dioxide catalyst.

[0007] In order to achieve the first object of the above invention, the technical solution adopted by the present invention is as follows:

[0008] The present invention provides a method for preparing a monolithic tungsten-doped ruthenium dioxide catalyst, comprising the following steps:

[0009] S1, dissolving tungstic acid in hydrogen peroxide, and heating and stirring to obtain a first solution;

[0010] S2, dissolving ruthenium trichloride in an alcohol solvent, stirring and mixing, to obtain a second solution;

[0011] S3, mixing the first solution and the second solution, and performing ultrasonic treatment to obtain a third solution;

[0012] S4. Dip-coating the third solution on a current collector, drying to obtain a precursor, and then heat-treating the precursor to obtain the monolithic tungsten-doped ruthenium dioxide catalyst.

[0013] The present invention discloses a method for preparing a monolithic tungsten-doped ruthenium dioxide catalyst. The method uses tungstic acid and ruthenium trichloride as raw materials, and dissolves the tungstic acid and ruthenium trichloride in different solvents to prepare precursor solutions, thereby ensuring safety and dissolution uniformity. Dissolving the tungstic acid in hydrogen peroxide can increase the solubility of the tungstic acid, and the tungstic acid and hydrogen peroxide promote the reaction during heating to produce a tungstic peroxide complex. However, during the subsequent drying process in step S4, the tungstic peroxide decomposes into tungstic acid, which then decomposes into tungstic oxide during heating. The purpose of using hydrogen peroxide for dissolution is mainly to increase the solubility of the tungstic acid and its uniformity in the first solution, thereby making the ruthenium and tungsten in the third solution more evenly dispersed. Furthermore, during the heating process, the tungsten element is more evenly doped on the surface of the ruthenium dioxide, thereby greatly improving the catalytic activity and catalytic stability of the catalyst. In addition, the monolithic tungsten-doped ruthenium dioxide catalyst is obtained by directly impregnating the third solution on the current collector and then drying and heating it, so that the tungsten-doped ruthenium dioxide catalyst is loaded on the current collector in the form of nano-sized particles, which not only increases the specific surface area of ​​the nano-particles, but also can expose more active sites, further improving the catalytic activity and catalytic stability of the catalyst, and greatly improving the utilization efficiency of ruthenium dioxide. In addition, the monolithic tungsten-doped ruthenium dioxide catalyst formed by directly impregnating the third solution on the current collector can be directly used as a working electrode, eliminating the need to add conductive additives and binders, simplifying the preparation process, and saving the preparation cost of the anode. The use of the impregnation coating method allows the third solution to be fully coated on the current collector, avoiding the waste of ruthenium trichloride and tungsten elements.

[0014] Furthermore, in step S1, the concentration of the first solution is 0.1 mol / L to 0.5 mol / L; and / or

[0015] The heating and stirring temperature is 40° C. to 80° C., and the heating and stirring time is 5 min to 20 min. The heating and stirring temperature and time can effectively promote the solubility and uniformity of tungstic acid in hydrogen peroxide.

[0016] Furthermore, in step S2, the concentration of the second solution is 0.1 mol / L to 0.5 mol / L; and / or

[0017] The stirring and mixing time is 5 minutes to 20 minutes, which can better promote the dissolution and uniformity of ruthenium trichloride in the alcohol solvent.

[0018] Furthermore, in step S2, the alcohol solvent is isopropyl alcohol, which has good solubility as a solvent for ruthenium trichloride and is also convenient for subsequent drying and heating treatment to form a monolithic tungsten-doped ruthenium dioxide catalyst.

[0019] Furthermore, in step S3, the volume ratio of the first solution to the second solution is 1:(0.5-3); and / or

[0020] The ultrasonic treatment time is 3 minutes to 10 minutes. The ultrasonic treatment can make the third solution evenly mixed, so that the subsequent tungsten element is more evenly distributed on the surface of ruthenium dioxide.

[0021] Furthermore, in step S4, the current collector is selected from titanium felt, carbon paper, or carbon cloth. Using titanium felt, carbon paper, or carbon cloth as the current collector allows the resulting monolithic tungsten-doped ruthenium dioxide catalyst to possess excellent structural and performance stability. Titanium felt, carbon paper, and carbon cloth all possess high electrical conductivity, significantly improving the electrode's electrical conductivity. Furthermore, the porous structure of titanium felt enhances the bond strength with the catalyst's active material, reducing contact resistance. The fibrous network of carbon paper and carbon cloth evenly distributes current, reducing the risk of localized overheating.

[0022] Furthermore, in step S4, the drying temperature is 60° C. to 80° C., and the drying time is 10 min to 20 min.

[0023] Furthermore, in step S4, the heat treatment is to place the precursor in a muffle furnace, raise the temperature to 300°C to 450°C at a heating rate of 5°C / min to 10°C / min, keep the temperature for 1h to 4h, and then naturally cool to room temperature.

[0024] In order to achieve the second purpose of the above invention, the technical solution adopted by the present invention is as follows:

[0025] The present invention provides a monolithic tungsten-doped ruthenium dioxide catalyst, which is prepared by the above-mentioned method for preparing a monolithic tungsten-doped ruthenium dioxide catalyst.

[0026] The monolithic tungsten-doped ruthenium dioxide catalyst prepared by the present invention has excellent electrocatalytic OER activity and outstanding stability, as well as the advantages of acid resistance.

[0027] In order to achieve the third purpose of the above invention, the technical solution adopted by the present invention is as follows:

[0028] The present invention provides an application of an integral tungsten-doped ruthenium dioxide catalyst. The integral tungsten-doped ruthenium dioxide catalyst described above or the integral tungsten-doped ruthenium dioxide catalyst prepared by the preparation method of the integral tungsten-doped ruthenium dioxide catalyst described above is used as an anode in an acidic water electrolysis hydrogen production device.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (1) The present invention provides a method for preparing an integral tungsten-doped ruthenium dioxide catalyst. Tungstic acid and ruthenium trichloride are used as raw materials, and tungstic acid and ruthenium trichloride are dissolved in different solvents to prepare precursor solutions, thereby ensuring safety and dissolution uniformity. Tungstic acid is dissolved in hydrogen peroxide to increase its solubility, and tungstic acid and hydrogen peroxide promote the reaction during heating to produce a complex of tungstic peroxide. However, in the subsequent drying process of step S4, tungstic peroxide decomposes into tungstic acid, and tungstic acid decomposes into tungstic acid during heating to produce tungsten oxide. The purpose of using hydrogen peroxide to dissolve is mainly to increase the solubility of tungstic acid and its uniformity in the first solution, thereby making the ruthenium and tungsten in the third solution more evenly dispersed. In the heating process, the tungsten element is more evenly doped on the surface of ruthenium dioxide, thereby greatly improving the catalytic activity and catalytic stability of the catalyst.

[0031] (2) The present invention provides a method for preparing a monolithic tungsten-doped ruthenium dioxide catalyst. The monolithic tungsten-doped ruthenium dioxide catalyst is prepared by directly impregnating and coating the third solution on the current collector, drying and heating the resulting solution. The tungsten-doped ruthenium dioxide catalyst is loaded on the current collector in the form of nano-sized particles, which not only increases the specific surface area of ​​the nano-particles but also exposes more active sites, further improving the catalytic activity and catalytic stability of the catalyst, and greatly improving the utilization efficiency of ruthenium dioxide. In addition, the monolithic tungsten-doped ruthenium dioxide catalyst formed by directly impregnating and coating the third solution on the current collector has a simple process and convenient operation. The tungsten-doped ruthenium dioxide catalyst is in situ generated on the current collector and can be directly used as a working electrode, eliminating the need to add conductive additives and binders, simplifying the preparation process, and saving the cost of preparing the anode. The use of the impregnation coating method allows the third solution to be fully coated on the current collector, thus avoiding the waste of ruthenium trichloride and tungsten elements.

[0032] (3) The monolithic tungsten-doped ruthenium dioxide catalyst of the present invention has excellent electrocatalytic OER activity, reaching 10 mA / cm in a 0.5 mol / L sulfuric acid electrolyte solution. 2 The overpotential required for the catalytic current density can be lower than 200 mV, or even lower than 190 mV.

[0033] (4) The monolithic tungsten-doped ruthenium dioxide catalyst of the present invention has excellent stability and can withstand 10 mA / cm 2 The current density was constant and the activity did not decay for 2500 hours. The current density was constant and the activity did not decay for 2500 hours. The current density was constant and the activity did not decay for 2500 hours. 2 The current density was kept constant and the device ran stably for 350 hours without any activity decay.

[0034] (5) The application of an integral tungsten-doped ruthenium dioxide catalyst of the present invention, which is used as an anode in an acidic water electrolysis hydrogen production device, has the advantages of high catalytic activity and good catalytic stability, and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0036] Figure 1 This is the X-ray powder diffraction pattern of the monolithic tungsten-doped ruthenium dioxide catalyst prepared in Example 1 of the present invention.

[0037] Figure 2 This is a scanning electron microscope image of the monolithic tungsten-doped ruthenium dioxide catalyst prepared in Example 1 of the present invention.

[0038] Figure 3 This is a scanning electron microscope energy scattering element distribution diagram of the monolithic tungsten-doped ruthenium dioxide catalyst prepared in Example 1 of the present invention.

[0039] Figure 4 Polarization curves of the acidic oxygen evolution performance test of the catalysts prepared in Example 1, Example 2, Example 3, Comparative Example 1, and Comparative Example 2 of the present invention.

[0040] Figure 5 The monolithic tungsten-doped ruthenium dioxide catalyst prepared in Example 1 of the present invention was subjected to a current density of 10 mA cm -2 Voltage-time curve of the acidic oxygen evolution performance test conducted under .

[0041] Figure 6 The monolithic tungsten-doped ruthenium dioxide catalyst prepared in Example 1 of the present invention was subjected to a current density of 100 mA cm -2 Voltage-time curve of the acidic oxygen evolution performance test conducted under . DETAILED DESCRIPTION

[0042] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0043] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. In the present invention, the singular forms "a", "an", "the" and "the" used in the embodiments and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0044] Among them, the OER mentioned in the present invention refers to the electrocatalyst oxygen evolution reaction.

[0045] In an embodiment of the present invention, a method for preparing a monolithic tungsten-doped ruthenium dioxide catalyst comprises the following steps:

[0046] S1, dissolving tungstic acid in hydrogen peroxide, and heating and stirring to obtain a first solution;

[0047] S2, dissolving ruthenium trichloride in an alcohol solvent, stirring and mixing, to obtain a second solution;

[0048] S3, mixing the first solution and the second solution, and performing ultrasonic treatment to obtain a third solution;

[0049] S4. Dip-coating the third solution on a current collector, drying to obtain a precursor, and then heat-treating the precursor to obtain the monolithic tungsten-doped ruthenium dioxide catalyst.

[0050] In some embodiments, in step S1, the concentration of the first solution is 0.1 mol / L to 0.5 mol / L; and / or

[0051] The heating and stirring temperature is 40° C. to 80° C.; the heating and stirring time is 5 min to 20 min.

[0052] In some embodiments, in step S2, the concentration of the second solution is 0.1 mol / L to 0.5 mol / L; and / or

[0053] The stirring and mixing time is 5 minutes to 20 minutes.

[0054] In some embodiments, in step S2, the alcohol solvent is isopropyl alcohol.

[0055] In some embodiments, in step S3, the volume ratio of the first solution to the second solution is 1:(0.5-3); and / or

[0056] The ultrasonic treatment time is 3 min to 10 min.

[0057] In some embodiments, in step S4, the current collector is one of titanium felt, carbon paper or carbon cloth.

[0058] In some embodiments, in step S4, the drying temperature is 60° C. to 80° C., and the drying time is 10 min to 20 min.

[0059] In some embodiments, in step S4, the heating treatment is to place the precursor in a muffle furnace, raise the temperature to 300°C to 450°C at a heating rate of 5°C / min to 10°C / min, keep the temperature for 1h to 4h, and then naturally cool to room temperature.

[0060] In an embodiment of the present invention, a monolithic tungsten-doped ruthenium dioxide catalyst is prepared by the above-mentioned method for preparing a monolithic tungsten-doped ruthenium dioxide catalyst.

[0061] In an embodiment of the present invention, an application of an integral tungsten-doped ruthenium dioxide catalyst, the integral tungsten-doped ruthenium dioxide catalyst or the integral tungsten-doped ruthenium dioxide catalyst prepared by the above-mentioned method of preparing an integral tungsten-doped ruthenium dioxide catalyst is used as an anode in an acidic water electrolysis hydrogen production device.

[0062] The following describes the details in conjunction with specific embodiments.

[0063] Example 1

[0064] A method for preparing a monolithic tungsten-doped ruthenium dioxide catalyst comprises the following steps:

[0065] S1. Dissolve tungstic acid in hydrogen peroxide, and heat and stir at 60° C. for 10 minutes to obtain a first solution. In this embodiment, the concentration of the first solution is 0.3 mol / L.

[0066] S2. Dissolve ruthenium trichloride in isopropyl alcohol and stir for 10 minutes to obtain a second solution. In this embodiment, the concentration of the second solution is 0.3 mol / L.

[0067] S3, mixing the first solution and the second solution in a volume ratio of 1:2, and performing ultrasonic treatment for 6 minutes to obtain a third solution;

[0068] S4. The third solution was dip-coated onto a 1 cm wide and 2 cm long titanium felt current collector. The precursor was dried at 80°C for 10 minutes to obtain a precursor. The precursor was then placed in a muffle furnace and heated to 350°C at a rate of 10°C / min, held for 2 hours, and then naturally cooled to room temperature to obtain a monolithic tungsten-doped ruthenium dioxide catalyst. The current collector was previously ultrasonically treated in acetone to remove surface contaminants and enhance surface hydrophilicity.

[0069] Example 2

[0070] A method for preparing a monolithic tungsten-doped ruthenium dioxide catalyst. Compared with Example 1, this embodiment differs in that the first solution and the second solution are in a volume ratio of 1:1. The remaining methods of this embodiment are the same as those of Example 1.

[0071] Example 3

[0072] A method for preparing a monolithic tungsten-doped ruthenium dioxide catalyst. Compared with Example 1, this embodiment differs in that the first solution and the second solution are in a volume ratio of 1:3. The remaining methods of this embodiment are the same as those of Example 1.

[0073] Example 4

[0074] A method for preparing a monolithic tungsten-doped ruthenium dioxide catalyst comprises the following steps:

[0075] S1. Dissolve tungstic acid in hydrogen peroxide, and heat and stir at 40°C to 80°C for 5min to 20min to obtain a first solution. In this embodiment, the concentration of the first solution is 0.1mol / L to 0.5mol / L.

[0076] S2. Dissolve ruthenium trichloride in isopropyl alcohol and stir for 5 to 20 minutes to obtain a second solution. In this embodiment, the concentration of the second solution is 0.1 mol / L to 0.5 mol / L.

[0077] S3, mixing the first solution and the second solution in a volume ratio of 1:(0.5-3), and performing ultrasonic treatment for 3 min to 10 min to obtain a third solution;

[0078] S4. Dip-coat the third solution onto a 1 cm wide and 2 cm long current collector titanium felt, carbon paper, or carbon cloth. Dry at 60°C to 80°C for 10 to 20 minutes to obtain a precursor. The precursor is then placed in a muffle furnace and heated to 350°C at a rate of 5°C / min, held for 2 hours, and then naturally cooled to room temperature to obtain a monolithic tungsten-doped ruthenium dioxide catalyst. The current collector is previously ultrasonically treated in acetone to remove surface contaminants and enhance surface hydrophilicity.

[0079] Example 5

[0080] A method for preparing a monolithic tungsten-doped ruthenium dioxide catalyst comprises the following steps:

[0081] S1. Dissolve tungstic acid in hydrogen peroxide, and heat and stir at 40° C. for 20 minutes to obtain a first solution. In this embodiment, the concentration of the first solution is 0.1 mol / L.

[0082] S2. Dissolve ruthenium trichloride in isopropyl alcohol and stir for 5 minutes to obtain a second solution. In this embodiment, the concentration of the second solution is 0.1 mol / L.

[0083] S3, mixing the first solution and the second solution at a volume ratio of 1:0.5, and performing ultrasonic treatment for 3 minutes to obtain a third solution;

[0084] S4. The third solution was dip-coated onto a 1 cm wide and 2 cm long current collector carbon paper. The precursor was dried at 60°C for 20 minutes to obtain a precursor. The precursor was then placed in a muffle furnace and heated to 300°C at a rate of 10°C / min, held for 2 hours, and then naturally cooled to room temperature to obtain a monolithic tungsten-doped ruthenium dioxide catalyst. The current collector was previously ultrasonically treated in acetone to remove surface contaminants and enhance surface hydrophilicity.

[0085] Example 6

[0086] A method for preparing a monolithic tungsten-doped ruthenium dioxide catalyst comprises the following steps:

[0087] S1. Dissolve tungstic acid in hydrogen peroxide, and heat and stir at 80° C. for 5 minutes to obtain a first solution. In this embodiment, the concentration of the first solution is 0.5 mol / L.

[0088] S2. Dissolve ruthenium trichloride in isopropyl alcohol and stir for 20 minutes to obtain a second solution. In this embodiment, the concentration of the second solution is 0.5 mol / L.

[0089] S3, mixing the first solution and the second solution in a volume ratio of 1:3, and performing ultrasonic treatment for 10 minutes to obtain a third solution;

[0090] S4. The third solution was dip-coated onto a 1 cm wide and 2 cm long current collector carbon cloth. The precursor was dried at 70°C for 150 min to obtain a precursor. The precursor was then placed in a muffle furnace and heated to 400°C at a rate of 10°C / min, held for 2 h, and then naturally cooled to room temperature to obtain a monolithic tungsten-doped ruthenium dioxide catalyst. The current collector was previously ultrasonically treated in acetone to remove surface contaminants and enhance surface hydrophilicity.

[0091] Example 7

[0092] A method for preparing a monolithic tungsten-doped ruthenium dioxide catalyst comprises the following steps:

[0093] S1. Dissolve tungstic acid in hydrogen peroxide, and heat and stir at 50° C. for 15 minutes to obtain a first solution. In this embodiment, the concentration of the first solution is 0.2 mol / L.

[0094] S2. Dissolve ruthenium trichloride in isopropyl alcohol and stir for 8 minutes to obtain a second solution. In this embodiment, the concentration of the second solution is 0.2 mol / L.

[0095] S3, mixing the first solution and the second solution in a volume ratio of 1:2, and performing ultrasonic treatment for 5 minutes to obtain a third solution;

[0096] S4. The third solution was dip-coated onto a 1 cm wide and 2 cm long titanium felt current collector. The precursor was dried at 65°C for 18 minutes to obtain a precursor. The precursor was then placed in a muffle furnace and heated to 450°C at a rate of 10°C / min, held for 2 hours, and then naturally cooled to room temperature to obtain a monolithic tungsten-doped ruthenium dioxide catalyst. The current collector was previously ultrasonically treated in acetone to remove surface contaminants and enhance surface hydrophilicity.

[0097] Example 8

[0098] A method for preparing a monolithic tungsten-doped ruthenium dioxide catalyst comprises the following steps:

[0099] S1. Dissolve tungstic acid in hydrogen peroxide, and heat and stir at 70° C. for 8 minutes to obtain a first solution. In this embodiment, the concentration of the first solution is 0.4 mol / L.

[0100] S2. Dissolve ruthenium trichloride in isopropyl alcohol and stir for 13 minutes to obtain a second solution. In this embodiment, the concentration of the second solution is 0.4 mol / L.

[0101] S3, mixing the first solution and the second solution at a volume ratio of 1:2.5, and performing ultrasonic treatment for 9 minutes to obtain a third solution;

[0102] S4. The third solution was dip-coated onto a 1 cm wide and 2 cm long titanium felt current collector. The precursor was dried at 75°C for 13 minutes to obtain a precursor. The precursor was then placed in a muffle furnace and heated to 350°C at a rate of 10°C / min, held for 1 hour, and then naturally cooled to room temperature to obtain a monolithic tungsten-doped ruthenium dioxide catalyst. The current collector was previously ultrasonically treated in acetone to remove surface contaminants and enhance surface hydrophilicity.

[0103] Example 9

[0104] A method for preparing a monolithic tungsten-doped ruthenium dioxide catalyst comprises the following steps:

[0105] S1. Dissolve tungstic acid in hydrogen peroxide, and heat and stir at 60° C. for 12 minutes to obtain a first solution. In this embodiment, the concentration of the first solution is 0.2 mol / L.

[0106] S2. Dissolve ruthenium trichloride in isopropyl alcohol and stir for 16 minutes to obtain a second solution. In this embodiment, the concentration of the second solution is 0.3 mol / L.

[0107] S3, mixing the first solution and the second solution at a volume ratio of 1:1.5, and performing ultrasonic treatment for 7 minutes to obtain a third solution;

[0108] S4. The third solution was dip-coated onto a 1 cm wide and 2 cm long titanium felt current collector. The precursor was dried at 75°C for 12 minutes to obtain a precursor. The precursor was then placed in a muffle furnace and heated to 300°C at a rate of 10°C / min, held for 3 hours, and then naturally cooled to room temperature to obtain a monolithic tungsten-doped ruthenium dioxide catalyst. The current collector was previously ultrasonically treated in acetone to remove surface contaminants and enhance surface hydrophilicity.

[0109] Example 10

[0110] A method for preparing a monolithic tungsten-doped ruthenium dioxide catalyst comprises the following steps:

[0111] S1. Dissolve tungstic acid in hydrogen peroxide, and heat and stir at 75° C. for 8 minutes to obtain a first solution. In this embodiment, the concentration of the first solution is 0.4 mol / L.

[0112] S2. Dissolve ruthenium trichloride in isopropyl alcohol and stir for 5 to 20 minutes to obtain a second solution. In this embodiment, the concentration of the second solution is 0.2 mol / L.

[0113] S3, mixing the first solution and the second solution in a volume ratio of 1:2, and performing ultrasonic treatment for 5 minutes to obtain a third solution;

[0114] S4. The third solution was dip-coated onto a 1 cm wide and 2 cm long current collector carbon cloth. The precursor was dried at 70°C for 14 minutes to obtain a precursor. The precursor was then placed in a muffle furnace and heated to 300°C at a rate of 10°C / min, held for 4 hours, and then naturally cooled to room temperature to obtain a monolithic tungsten-doped ruthenium dioxide catalyst. The current collector was previously ultrasonically treated in acetone to remove surface contaminants and enhance surface hydrophilicity.

[0115] Comparative Example 1

[0116] A method for preparing a tungsten catalyst. The difference between this comparative example and Example 1 is that this comparative example omits steps S2 and S3 of Example 1, that is, omits the addition of ruthenium trichloride. The tungsten catalyst is prepared, comprising the following steps:

[0117] A method for preparing a tungsten catalyst comprises the following steps:

[0118] S1. Dissolve tungstic acid in hydrogen peroxide, and heat and stir at 60° C. for 100 min to obtain a first solution. In this embodiment, the concentration of the first solution is 0.3 mol / L.

[0119] S2. The first solution was dip-coated onto a 1 cm wide and 2 cm long titanium felt current collector. The precursor was dried at 80°C for 10 minutes to obtain a precursor. The precursor was then placed in a muffle furnace and heated to 350°C at a rate of 10°C / min, held for 2 hours, and then naturally cooled to room temperature to obtain a tungsten catalyst. The current collector was previously ultrasonically treated in acetone to remove surface contaminants and enhance surface hydrophilicity.

[0120] Comparative Example 2

[0121] A method for preparing a commercial ruthenium dioxide catalyst. This comparative example differs from Example 1 in that tungsten doping is omitted and commercial ruthenium dioxide is directly used as a raw material. The method comprises the following steps:

[0122] S1. Pretreatment of the current collector: The current collector titanium felt is pre-ultrasonicated in acetone to remove surface contaminants and enhance surface hydrophilicity;

[0123] S2. Weigh 5 mg of commercial ruthenium dioxide and disperse it evenly in 950 mL of ethanol by ultrasonic treatment. Add 50 mL of conductive binder and ultrasonicate to obtain a uniform dispersion. Draw 30 mL of the dispersion and drop-coat it onto the current collector treated in step S1. Dry the mixture at 80°C for 10 minutes to obtain the commercial ruthenium dioxide catalyst.

[0124] Structural morphology characterization

[0125] (1) X-ray diffraction analysis

[0126] The monolithic tungsten-doped ruthenium dioxide catalyst prepared by the preparation method of a monolithic tungsten-doped ruthenium dioxide catalyst in Example 1 was subjected to X-ray diffraction analysis (XRD). Figure 1 shown.

[0127] like Figure 1 As shown, the X-ray diffraction pattern shows that the diffraction peaks appearing at 2θ angles of 28.1 degrees, 35.1 degrees and 54.3 degrees correspond to the (110), (101) and (211) crystal planes of RuO2, respectively, indicating that the present invention has successfully synthesized the ruthenium dioxide-based catalyst.

[0128] (2) Morphological characterization by scanning electron microscopy

[0129] The monolithic tungsten-doped ruthenium dioxide catalyst prepared by the preparation method of a monolithic tungsten-doped ruthenium dioxide catalyst in Example 1 was characterized by scanning electron microscopy (SEM). Figure 2 shown.

[0130] Depend on Figure 2 It can be seen that the monolithic tungsten-doped ruthenium dioxide catalyst prepared in the present invention presents a spherical nanoparticle morphology and is relatively uniform in shape.

[0131] (3) SEM energy scattering element distribution analysis

[0132] The monolithic tungsten-doped ruthenium dioxide catalyst prepared by the preparation method of a monolithic tungsten-doped ruthenium dioxide catalyst in Example 1 was subjected to scanning electron microscope energy scattering element distribution analysis. Figure 3 shown.

[0133] Depend on Figure 3 It can be seen that in the integral tungsten-doped ruthenium dioxide catalyst prepared by the present invention, ruthenium, tungsten and oxygen elements are evenly distributed, indicating that the tungsten element is evenly doped on the surface of ruthenium dioxide, thus proving the successful doping of tungsten.

[0134] Performance testing of oxygen evolution reaction in hydrogen production by acidic water electrolysis

[0135] (1) Catalytic activity detection

[0136] The monolithic tungsten-doped ruthenium dioxide catalysts prepared in Examples 1, 2, and 3 of the present invention, as well as the tungsten catalyst of Comparative Example 1 and the commercial ruthenium dioxide catalyst of Comparative Example 2 were respectively subjected to acidic oxygen evolution performance tests.

[0137] The test method is as follows: Acidic water electrolysis OER was carried out in a 100 mL electrolytic cell with a three-electrode system, which was open to the atmosphere. A Shanghai Chenhua electrochemical workstation and a three-electrode system (reference electrode: Ag / AgCl (saturated KCl), counter electrode: 1*1 cm 2 The OER performance of water electrolysis was investigated in an acidic electrolyte (0.5 M sulfuric acid solution) using a platinum sheet and a working electrode (the catalysts of Examples 1-3 and Comparative Examples 1-2, respectively).

[0138] The OER activity of acidic water electrolysis was tested using linear sweep voltammetry, usually at a current density of 10 mA / cm 2 The OER activity is determined by the overpotential value, where the measurement voltage range is 1.1V-1.8V (vs. RHE). Since the theoretical minimum potential required for the OER reaction is 1.23V, the overpotential is the current density of 10mA / cm 2 The voltage value measured in the following experiment is the voltage value of the reference electrode (0.197 V in this experiment) plus the voltage value, and then subtract 1.23 V. The lower the overpotential, the higher the OER activity.

[0139] Among them, the acidic oxygen evolution performance test results of the monolithic tungsten-doped ruthenium dioxide catalysts prepared in Example 1, Example 2, and Example 3, as well as the tungsten catalyst of Comparative Example 1 and the commercial ruthenium dioxide catalyst of Comparative Example 2 are as follows: Figure 4 shown.

[0140] Depend on Figure 4 The test results show that in the polarization curves of Comparative Example 1, Comparative Example 2, Example 1, Example 2, and Example 3, the current density is 10 mA cm -2 The corresponding overpotentials are none, 330 mV, 180 mV, 191 mV, and 186 mV, respectively. Examples 1 and 3 have extremely low overpotentials, indicating that the monolithic tungsten-doped ruthenium dioxide catalysts prepared in Examples 1 and 3 have extremely high OER activity. Therefore, the monolithic tungsten-doped ruthenium dioxide catalyst prepared in the present invention has high oxygen evolution catalytic activity.

[0141] (2) Catalytic stability test

[0142] The stability test of acidic water electrolysis OER was performed by chronopotentiometry, usually at a constant current density (10 mA / cm 2 ) to observe how long it can maintain its voltage within a certain range. The longer the maintenance time, the better its OER stability.

[0143] The monolithic tungsten-doped ruthenium dioxide catalyst prepared in Example 1 was heated at a current density of 10 mA cm -2 The stability test of acidic water electrolysis OER was carried out under Figure 5 shown.

[0144] The monolithic tungsten-doped ruthenium dioxide catalyst prepared in Example 1 was heated at a current density of 100 mA cm -2 The stability test of acidic water electrolysis OER was carried out under Figure 6 shown.

[0145] Depend on Figure 5 The test results show that the voltage-time curve of the monolithic tungsten-doped ruthenium dioxide catalyst prepared by the present invention shows that at a current density of 10 mA cm -2 The stability test was carried out under the current density of 10 mA cm-1. The results showed that the monolithic tungsten-doped ruthenium dioxide catalyst prepared by the present invention maintained its potential unchanged after being kept at the current density for 2500 hours, indicating that Example 1 has a stable performance at a current density of 10 mA cm-1. -2 After long-term stability testing, there is still no loss of activity, showing extremely strong stability.

[0146] Depend on Figure 6 The test results show that the voltage-time curve of the monolithic tungsten-doped ruthenium dioxide catalyst prepared by the present invention shows that at a current density of 100 mA cm -2 The stability test was carried out under the current density of 100 mA cm-1. The results showed that the monolithic tungsten-doped ruthenium dioxide catalyst prepared by the present invention maintained its potential unchanged after being kept at the current density for 350 hours, indicating that Example 1 has a stable performance at a current density of 100 mA cm-1. -2 After long-term stability testing, there is still no loss of activity, showing extremely strong stability.

[0147] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A method for preparing a monolithic tungsten-doped ruthenium dioxide catalyst, characterized in that: The following steps are involved: S1, dissolving tungstic acid in hydrogen peroxide, and heating and stirring to obtain a first solution; S2, dissolving ruthenium trichloride in an alcohol solvent, stirring and mixing, to obtain a second solution; S3, mixing the first solution and the second solution, and performing ultrasonic treatment to obtain a third solution; S4. Dip-coating the third solution on a current collector, drying to obtain a precursor, and then heat-treating the precursor to obtain the monolithic tungsten-doped ruthenium dioxide catalyst.

2. The method for preparing a monolithic tungsten-doped ruthenium dioxide catalyst according to claim 1, wherein: In step S1, the concentration of the first solution is 0.1 mol / L to 0.5 mol / L; and / or The heating and stirring temperature is 40° C. to 80° C.; the heating and stirring time is 5 min to 20 min.

3. The method for preparing a monolithic tungsten-doped ruthenium dioxide catalyst according to claim 1, wherein: In step S2, the concentration of the second solution is 0.1 mol / L to 0.5 mol / L; and / or The stirring and mixing time is 5 minutes to 20 minutes.

4. The method for preparing a monolithic tungsten-doped ruthenium dioxide catalyst according to claim 1, wherein: In step S2, the alcohol solvent is isopropyl alcohol.

5. The method for preparing a monolithic tungsten-doped ruthenium dioxide catalyst according to claim 1, wherein: In step S3, the volume ratio of the first solution to the second solution is 1:(0.5-3); and / or The ultrasonic treatment time is 3 min to 10 min.

6. The method for preparing a monolithic tungsten-doped ruthenium dioxide catalyst according to claim 1, wherein: In step S4, the current collector is one of titanium felt, carbon paper or carbon cloth.

7. The method for preparing a monolithic tungsten-doped ruthenium dioxide catalyst according to claim 1, wherein: In step S4, the drying temperature is 60° C. to 80° C., and the drying time is 10 min to 20 min.

8. The method for preparing a monolithic tungsten-doped ruthenium dioxide catalyst according to claim 1, wherein: In step S4, the heat treatment is to place the precursor in a muffle furnace, raise the temperature to 300°C to 450°C at a heating rate of 5°C / min to 10°C / min, keep the temperature for 1h to 4h, and then naturally cool to room temperature.

9. A monolithic tungsten-doped ruthenium dioxide catalyst, characterized in that: The catalyst is prepared by the preparation method of the monolithic tungsten-doped ruthenium dioxide as described in claims 1 to 8.

10. An application of a monolithic tungsten-doped ruthenium dioxide catalyst, characterized in that: The monolithic tungsten-doped ruthenium dioxide catalyst described in claim 9 or the monolithic tungsten-doped ruthenium dioxide catalyst prepared by the preparation method of the monolithic tungsten-doped ruthenium dioxide catalyst described in any one of claims 1 to 8 is used as the anode in an acidic water electrolysis hydrogen production device.

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