A preparation method of a polyacid-derived tungsten-doped ruthenium oxide nanoparticle electrocatalyst

Abstract

The application relates to the technical field of new materials, in particular to a preparation method of a tungsten-doped ruthenium oxide nanoparticle electrocatalyst derived from a polyacid. 10 [alpha-SiW9O 34 ] (referred to as SiW9) is compounded with ruthenium chloride (RuCl3) through a "sugar bubble method" to obtain foamed glucose balls; after high-temperature heat treatment, tungsten-doped ruthenium oxide nanoparticles are obtained as an acidic electrolytic water oxygen evolution catalyst, and then the structure composition and electrocatalytic acidic oxygen evolution reaction (OER) performance of the catalyst are systematically studied. In the application, the polyacid precursor with a definite structure can effectively inhibit the agglomeration of ruthenium oxide during high-temperature treatment, so that more catalytic active sites are exposed; moreover, the W doping derived from the polyacid can not only effectively regulate the electronic structure of Ru sites but also inhibit the excessive oxidation of the Ru sites, so that the electrocatalytic OER activity and stability of the RuO2 are improved.

Description

Technical Field

[0001] This invention relates to the field of new materials technology, specifically to a method for preparing a polyacid-derived tungsten-doped ruthenium oxide nanoparticle electrocatalyst. Background Technology

[0002] With fossil fuels dwindling and greenhouse gas emissions worsening, the search for alternative energy sources has become increasingly urgent in recent decades. H2, as a renewable energy carrier, has the potential to replace carbon-based fuels in transportation and mobility applications. Water, a vast resource on Earth, offers a cost-effective and readily available method for producing green hydrogen using sustainable electricity, and is considered a key element in achieving future carbon neutrality goals. However, the oxygen evolution reaction (OER) in water electrolysis, a critical and bottleneck reaction in hydrogen production technology, significantly hinders overall efficiency due to its slow reaction kinetics.

[0003] Currently, significant progress has been made in the preparation and synthesis of Ru-based catalysts in the field of OER (Oxygen Exchange Reactor), including heteroatom doping, hole introduction, size control, interaction with the support, and microstructure control. However, the development of ruthenium-based acidic OER catalysts still faces certain challenges: under the applied OER potential, RuO2 is easily over-oxidized to produce soluble RuO4, and the acidic environment strongly corrodes RuO2, making it impossible to maintain a long-term stable OER process. This severely hinders its application in proton exchange membrane electrolysis (PEMWE) hydrogen production technology. Therefore, improving the activity of Ru-based catalysts and inhibiting the over-oxidation and dissolution of Ru to enhance stability has become a key issue for the application of ruthenium oxide in PEMWE hydrogen production. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing a polyacid-derived tungsten-doped ruthenium oxide nanoparticle electrocatalyst, in order to solve the problems of catalyst structure collapse and poor stability caused by excessive oxidation of Ru mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for preparing a polyacid-derived tungsten-doped ruthenium oxide nanoparticle electrocatalyst, comprising:

[0006] Design and synthesize Keggin-type vacancy polyacid K 10 [α-SiW9O 34 SiW9 (abbreviated as SiW9) was synthesized with ruthenium chloride (RuCl3) using the "sugar bubble method".

[0007] After high-temperature heat treatment, tungsten-doped ruthenium oxide nanoparticles (W-RuO2) electrocatalyst were obtained, and then the structural composition and electrocatalytic oxygen evolution reaction performance of the catalyst were systematically studied.

[0008] Utilizing Keggin-type vacancy polyacid K 10 [α-SiW9O 34 Using SiW9 (abbreviated as SiW9) as a precursor, SiW9 is combined with RuCl3 via the "sugar bubble method". The vacancy structure of SiW9 can anchor ruthenium atoms and inhibit ruthenium aggregation during high-temperature heat treatment. Tungsten-doped ruthenium oxide nanoparticle electrocatalyst (W-RuO2) is formed through high-temperature heat treatment.

[0009] The preparation method includes the following steps:

[0010] Step 1: Keggin-type vacancy polyacid K 10 [α-SiW9O 34 Synthesis of SiW9 (abbreviated as SiW9): Sodium tungstate dihydrate and sodium metasilicate were dissolved in deionized water and heated to 80-100℃. Hydrochloric acid solution was slowly added and heated and stirred until the solution evaporated to 30 mL. After cooling to room temperature, the solution was filtered to obtain a clear filtrate. Sodium silicate solution was slowly added and stirred until the precipitate was completely precipitated. The precipitate was washed with KCl solution, ethanol and diethyl ether in sequence. The product was obtained by suction filtration and vacuum drying to obtain a white powder.

[0011] Step 2: Preparation of tungsten-doped ruthenium oxide nanoparticles (W-RuO2): Glucose and urea were weighed and sonicated to completely dissolve in deionized water. SiW9 and RuCl3 were weighed and dissolved in the aforementioned solution. After stirring evenly, the beaker was placed in a forced-air drying oven and heated to obtain foamed glucose spheres. Subsequently, these were transferred to a muffle furnace and heated to obtain W-RuO2 nanoparticles.

[0012] Preferably, the SiW9 with a diameter of 1-2 nm is used as a precursor, and its vacancy structure can effectively anchor Ru sites and inhibit the aggregation of RuO2 during high-temperature heat treatment.

[0013] Preferably, the vacancy-deficient polyacid SiW9 is selected as the precursor, and a stable tungsten-doped ruthenium oxide nanoparticle electrocatalyst is obtained through the interaction between high-valence tungsten and ruthenium.

[0014] Preferably, the RuCl3 and SiW9 composite is prepared by first adding SiW9 to a urea solution in which glucose is completely dissolved, stirring until it is completely dissolved, and then adding RuCl3 and stirring for at least 15 minutes to ensure a homogeneous solution is obtained.

[0015] Preferably, the "glucose bubble method" uses glucose as a template to obtain a foamed and expanded glucose sphere under heating conditions. This method can ensure the uniform compounding of ruthenium and polyacid precursors.

[0016] Preferably, the glucose spheres are calcined in a muffle furnace at a temperature of 400–600°C.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] 1. Polyacid precursors containing vacancy structures can initially anchor ruthenium during expansion. Polyacid precursors can effectively inhibit the aggregation of ruthenium oxide at high temperatures, exposing more active sites and exhibiting good electrocatalytic oxygen evolution (OER) performance.

[0019] 2. Benefiting from the effective anchoring of ruthenium atoms by the vacancy structure during the "sugar bubble method" and the electronic interaction between tungsten and ruthenium, high-valence tungsten can suppress the excessive oxidation of ruthenium in acidic OER, and W-RuO2 exhibits good stability. Attached Figure Description

[0020] Figure 1 This is the infrared absorption spectrum obtained using SiW9 polyacids in this invention;

[0021] Figure 2 This is a schematic diagram of the structure using a scanning electron microscope.

[0022] Figure 3 This is a schematic diagram of the X-ray diffraction of the structure of the present invention;

[0023] Figure 4 This is a schematic diagram of the linear scanning voltammetry curve of the structure of the present invention;

[0024] Figure 5 This is a schematic diagram of the structural stability test of the present invention. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Please see Figure 1-5 One embodiment provided by the present invention:

[0027] A method for preparing a polyacid-derived tungsten-doped ruthenium oxide nanoparticle electrocatalyst includes the following steps:

[0028] Step 1: Keggin-type vacancy polyacid K 10 [α-SiW9O 34Synthesis of SiW9 (abbreviated as SiW9): Sodium tungstate dihydrate and sodium metasilicate were dissolved in deionized water and heated to 80-100℃. Hydrochloric acid solution was slowly added and heated and stirred until the solution evaporated to 30 mL. After cooling to room temperature, the solution was filtered to obtain a clear filtrate. Sodium silicate solution was slowly added and stirred until the precipitate was completely precipitated. The precipitate was washed with KCl solution, ethanol and diethyl ether in sequence. The product was obtained by suction filtration and vacuum drying to obtain a white powder.

[0029] Step 2: Preparation of tungsten-doped ruthenium oxide nanoparticles (W-RuO2): Weigh 5g of glucose and 1g of urea, and sonicate them until completely dissolved in deionized water. Weigh 29.63mg of SiW9 and 83.15mg of RuCl3 and dissolve them in the above solution. After stirring evenly, place the beaker in a forced-air drying oven and heat to obtain foamed glucose spheres. Then place them in a muffle furnace and heat to obtain W-RuO2 nanoparticles.

[0030] Furthermore, the infrared absorption spectrum obtained using SiW9 indicates the successful synthesis of the polyacid precursor.

[0031] Furthermore, using SiW9 with a diameter of 1–2 nm as a precursor, the excessive oxidation of ruthenium is avoided through the interaction between high-valence tungsten and ruthenium, resulting in a stable tungsten-doped ruthenium oxide nanoparticle electrocatalyst (W-RuO2). Scanning electron microscopy (SEM) images obtained using W-RuO2 show that W-RuO2 was successfully synthesized as nanoparticles.

[0032] Furthermore, after the high-temperature heat treatment, the structures of the tungsten-doped ruthenium oxide nanoparticle electrocatalyst (W-RuO2) and ruthenium oxide (RuO2) were determined using X-ray diffraction (XRD). The test results showed a slight shift in the diffraction peaks of W-RuO2 compared to RuO2, indicating successful tungsten doping. In addition, W-RuO2 exhibited a wider full width at half maximum (FWHM) than RuO2, and according to the Scherrer equation, the nanoparticle size of W-RuO2 was smaller, demonstrating that the presence of the polyacid precursor effectively reduced the size of the ruthenium oxide nanoparticles.

[0033] Furthermore, the glucose spheres were used as calcination reactants and calcined in a muffle furnace at a temperature of 400–600 °C. Linear sweep voltammetry (LSV) curves of oxygen evolution in water electrolysis were obtained using W-RuO2 calcined at 400 °C, 500 °C, and 600 °C. It can be seen that regardless of the temperature at 10 mA cm⁻¹... -2 The low current density is still 200 mA cm⁻¹ -2 Under high current density, W-RuO2 obtained by high-temperature heat treatment at 400℃ has the smallest overpotential.

[0034] Furthermore, the high-temperature heat treatment yields a fluffy product, which is then thoroughly ground into uniform particles using an agate mortar and pestle. It is washed three times with deionized water and centrifuged to ensure the removal of potassium ions from the polyacid precursor. Linear sweep voltammetry (LSV) curves of oxygen evolution in water electrolysis obtained using W-RuO2 and commercial RuO2 show that regardless of the temperature at 10 mA cm⁻¹... -2 The low current density is still 200 mA cm⁻¹ -2 At high current densities, W-RuO2 exhibits the lowest overpotential, superior to commercial RuO2 catalysts, and demonstrates excellent electrochemical properties.

[0035] Furthermore, the tungsten-doped ruthenium oxide nanoparticle electrocatalyst obtained by the aforementioned preparation method is used for the electrocatalytic oxygen evolution reaction. Stability testing of oxygen evolution in water electrolysis using W-RuO2 was performed, and the results showed that at 10 mA cm⁻¹... -2 The W-RuO2 catalyst can operate stably for 100 hours at a given current density, demonstrating stable electrocatalytic oxygen evolution stability.

[0036] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A method for preparing a polyacid-derived tungsten-doped ruthenium oxide nanoparticle electrocatalyst, characterized by, Comprising: Design and synthesis of Keggin-type vacancy polyoxometalate nanoclusters K 10 [α-SiW9O 34 ](referred to as SiW9) as a precursor, SiW9 containing vacancy structure and ruthenium chloride (RuCl3) were compounded by "sugar bubble method", and the vacancy structure was used to anchor Ru site; after high temperature heat treatment, tungsten doped ruthenium oxide nanoparticles (W-RuO2) were obtained as an acidic oxygen evolution reaction (OER) electrocatalyst, and the structure and electrocatalytic oxidation performance of the catalyst were systematically studied. The electrochemical performance test of the prepared electrode material was carried out by using Shanghai Chenhua electrochemical workstation CHI760E, Ag / AgCl electrode was used as reference electrode, platinum sheet was used as counter electrode, the prepared electrode was used as working electrode, and 0.5M H2SO4 solution was used as electrolyte solution for electrocatalytic OER performance test. The preparation method comprises the following steps: Step 1: Synthesis of Keggin-type vacancy polyoxometalate K 10 [α-SiW9O 34 ](abbreviated as SiW9): Dissolve sodium tungstate dihydrate and sodium metasilicate in deionized water, heat to 80-100 °C, slowly add hydrochloric acid solution, continue to heat and stir until the solution evaporates to 30 mL, cool to room temperature, filter to get clear filtrate, slowly add sodium silicate solution, continue to stir until the precipitate is completely precipitated, wash the precipitate with KCl solution, ethanol and ether in turn, suction filter, and vacuum dry to get white powder. Step 2: Preparation of tungsten-doped ruthenium oxide nanoparticles (W-RuO2): Weigh glucose and urea, and ultrasonically dissolve them in deionized water. Then, weigh an appropriate amount of SiW9 and RuCl3, and dissolve them in the above solution. After stirring uniformly, place the beaker in a blast oven to obtain foamed glucose spheres. Then, transfer the foamed glucose spheres to a muffle furnace to obtain W-RuO2 nanoparticles.

2. The method according to claim 1, wherein the method is characterized by: The use of SiW9 polyacid containing a vacancy structure as a precursor, which anchors ruthenium through the vacancy structure and inhibits the agglomeration of ruthenium during high-temperature heat treatment, is included but not limited to.

3. The method of claim 1, wherein the method is characterized by: The use of RuCl3 as a Ru source and a polyacid precursor to obtain stable tungsten-doped ruthenium oxide W-RuO2 nanoparticle electrocatalysts after high-temperature treatment is included but not limited to.

4. The method of claim 1, wherein the method is characterized by: In step 2, SiW9 is first added to the solution in which glucose and urea are completely dissolved, and then RuCl3 is added and stirred for at least 15 min to ensure a uniform solution.

5. The method of claim 1, wherein the method is characterized by: The glucose spheres are used as calcination reactants, and are calcined in a muffle furnace at a calcination temperature of 400-600°C.

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