Boron and metal double-doping modified ruthenium oxide anode catalyst as well as preparation method and application thereof

Abstract

The invention provides a boron and metal double-doping modified ruthenium oxide anode catalyst as well as a preparation method and application thereof, and belongs to the technical field of new energy materials and electrochemical catalysis. The preparation method comprises the following steps: firstly, dissolving urea and glucose in deionized water to serve as a structure-directing agent, then adding boric acid, ruthenium chloride and gallium nitrate hydrate, stirring at room temperature until the materials are dissolved, adopting a hydrothermal method to obtain a gel solid precursor, performing washing treatment and vacuum drying, and performing heat treatment in an atmosphere to obtain the boron and metal double-doped ruthenium oxide electrocatalyst. The synthesis process is simple and easy to implement, doping modification of boron and metal not only reduces the loading amount of precious metal ruthenium, but also improves the activity and stability of the catalyst, a good thought is provided for double-element doped ruthenium oxide, and the method has industrial application potential.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy materials and electrochemical catalysis, and specifically relates to a boron-and-metal dual-doped ruthenium oxide anode catalyst, and a preparation method and application thereof. Background Art

[0002] With the development of economy and society, the consumption of non-renewable energy such as coal, oil and natural gas has seriously led to environmental damage, air pollution and greenhouse effect. When these problems come one after another, people begin to increase the demand for green and sustainable energy such as wind energy, tidal energy and solar energy. But as we all know, these energy sources are intermittent energy sources at present, and they are often not reasonably transported, stored and utilized, resulting in certain waste. Hydrogen energy can be used as an energy carrier of these intermittent energy sources. It has high energy density and is clean and pollution-free. It is one of the most popular secondary energy sources at present. It is crucial to build a hydrogen society by converting these intermittent electrical energies into hydrogen energy through water electrolysis. Using proton exchange membrane to produce hydrogen by water electrolysis can well solve many problems existing in alkaline water decomposition, such as low hydrogen production efficiency, low upper limit of current density and high impedance. However, due to the strong acidity and strong oxidation characteristics of the electrolysis environment of acidic water decomposition, the acidic oxygen evolution reaction (OER) faces great challenges in stability.

[0003] At present, Ir-based catalysts are commonly used in industrial water electrolysis, which have high stability and performance. However, Ir catalysts are expensive and have relatively high overpotentials. -2 The overpotential under current density is generally 250mV and above (Ailong Li, et al. Atomically dispersed hexavalent iridium oxide from MnO2 reduction for oxygen evolution catalysis [J]. Science, 2024, 384 (5193): 666-670). At this time, the relatively cheap and low overpotential Ru-based catalysts are attracting more and more attention. Despite this, the stability problem of Ru-based catalysts has always plagued researchers, and how to deal with the relationship between stability and voltage needs to be solved urgently. Ru cations are easily transitionally oxidized in an acidic environment during the OER process to produce soluble substances, causing the crystal structure of the catalyst to collapse, which greatly limits its service life in practical applications. Researchers have tried a variety of strategies, including metal doping, strain effects, surface reconstruction, morphology control, and electronic structure regulation, to improve the activity and durability of Ru-based electrocatalysts. Although some progress has been made, most Ru-based catalysts are only 10mAcm -2The stability can only be maintained for a few hours at a current density, far from meeting the requirements of commercial applications. The team of Jingjun Liu from Beijing University of Chemical Technology (Jingjun Liu, etal. Oxygen vacancy - electron polarons featured InSnRuOz oxides: orderly and concerted In - Ov - Ru - O - Sn substructures for acidic water oxidation[J]. Advanced Materials, 2024, 36(52): 2414579) for the first time synthesized InSnRuO2 with controlled oxygen defect (O v ) density through an isostructural substitution strategy. The overpotential of this catalyst at 10 mA cm -2 is 183 mV and it can operate stably for 200 h. However, problems such as low catalytic activity and poor continuous stability ability in acidic environments have not been completely solved, making it difficult to meet the strong acid resistance and high activity under industrial conditions. Therefore, developing Ru - based OER catalysts that can work stably in acidic environments for a long time has important practical significance. Summary of the Invention

[0004] In order to break free from the shackles of the above - mentioned prior art and solve the problems of poor stability and high overpotential of the anode catalyst in current acidic OER. The present invention proposes a ruthenium oxide anode catalyst modified by boron and metal co - doping, its preparation method and application, which can be directly applied to electrocatalytic oxygen evolution reaction in acidic environments and exhibit excellent activity and stability.

[0005] The present invention adopts the following technical solutions:

[0006] A ruthenium oxide anode catalyst modified by boron and metal co - doping, the morphology of the anode catalyst is dense nano - spheres, and the size of the nano - spheres is 40 - 60 nm. Among them, the molar ratio of boron, doped metal, and ruthenium is (3 - 3.3):(3 - 0.2):1.

[0007] A preparation method of a ruthenium oxide anode catalyst modified by boron and metal co - doping, the preparation method includes the following steps:

[0008] Step 1, weigh a certain amount of glucose and urea and dissolve them in deionized water, stir until completely dissolved to obtain a mixed solution A.

[0009] Step 2, weigh a certain amount of ruthenium chloride, nitrate hydrate, and boric acid and dissolve them in deionized water, stir until completely dissolved to obtain a mixed solution B.

[0010] Step 3: Mix the mixed solution A and the mixed solution B evenly and stir until completely dissolved to obtain a precursor mixed solution C.

[0011] Step 4: Place the precursor solution C in a hydrothermal autoclave and perform hydrothermal operation in an oven. After washing, a gel solid precursor is obtained.

[0012] Step 5: Dry the obtained gel solid precursor in a vacuum drying oven and grind the obtained solid product into powder.

[0013] Step 6: Sinter the powder in a tubular furnace with air as the gas atmosphere to form a black powder, and cool it to room temperature to obtain a ruthenium oxide anode catalyst modified by boron and metal co-doping.

[0014] Further, in the above step 1, the concentrations of glucose and urea in the mixed solution A are 0.4 - 1 mol / L and 0.1 - 0.6 mol / L respectively.

[0015] Further, in the above step 2, the concentrations of ruthenium chloride, nitrate hydrate and boric acid in the mixed solution B are 0.05 - 0.1 mol / L, 0.02 - 0.15 mol / L and 0.15 - 0.33 mol / L respectively. Among them, the nitrate hydrate is gallium nitrate hydrate, indium nitrate hydrate or aluminum nitrate hydrate, preferably gallium nitrate hydrate, and the concentration of gallium nitrate hydrate is preferably 0.05 - 0.1 mol / L.

[0016] Further, in the above step 3, the volume ratio of the mixed solution A to the mixed solution B is 1:1 - 2:1.

[0017] Further, in the above step 4, the hydrothermal temperature is 100 - 180 °C, the hydrothermal time is 6 - 12 h. After hydrothermal treatment, wash it 3 - 5 times with anhydrous ethanol and deionized water in a centrifuge until the upper liquid is clear and transparent.

[0018] Further, in the above step 5, the drying time is 6 - 18 h and the drying temperature is 50 - 70 °C.

[0019] Further, in the above step 6, the sintering process is: heat up to 400 - 500 °C at a heating rate of 2 - 5 °C / min and keep the temperature for 8 - 16 h.

[0020] An application of a ruthenium oxide anode catalyst modified by boron and metal co-doping in hydrogen production by electrolyzing water. The specific process of hydrogen production by electrolyzing water is as follows: use the prepared anode catalyst as the working electrode, Ag / AgCl electrode as the reference electrode, and carbon rod as the counter electrode to perform acidic electrolytic water oxygen evolution reaction in a 0.5 mol / L sulfuric acid solution saturated with oxygen.

[0021] The innovation of the present invention lies in that by introducing boron (B), the synergistic effect of the doped metal element and ruthenium (Ru) at the bimetallic sites is promoted. On the one hand, the introduction of boron reduces the crystal configuration of the catalyst. Compared with crystalline substances, in addition to providing significant active sites, the amorphous structure can actively adjust the Ru-O bond and optimize the adsorption energy of oxygen intermediates, thus achieving a significant improvement in activity. On the other hand, the electronic spatial regulation of B optimizes the bimetallic synergistic effect between the doped metal element and ruthenium (Ru). The common synergy between the non-metal B and the doped metal element optimizes the catalytic activity of RuO2, and after doping, the dissolution effect of Ru is inhibited, effectively improving the acid resistance of RuO2 during the OER process and improving its stability.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] (1) The synthesis process of the present invention is simple and feasible. Ruthenium oxide modified by co-doping of boron and metal elements can be prepared only by the sol-gel method combined with calcination. Compared with existing methods such as the molten salt method and electrospinning method, it can be prepared on a large scale at low cost.

[0024] (2) The ruthenium oxide catalyst modified by co-doping of boron and metal elements prepared by the present invention exhibits excellent activity and stability during the acidic OER process. By co-doping B and metal elements, the present invention solves the problems of poor activity and stability of ruthenium oxide catalysts, reducing the overpotential at 10 mA cm -2 to about 170 mV and increasing the stability from 100 hours to more than 1400 hours, greatly improving the catalytic activity of ruthenium oxide catalysts and their stability in acidic media.

[0025] (3) The iridium-based catalysts commonly used in industrial acidic electrolyzed water are expensive. The present invention uses Ru-based catalysts to replace precious metal iridium, greatly reducing the cost and having better performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 SEM image of BGa-RuO2 in Example 1.

[0027] Figure 2 Element mapping diagram of BGa-RuO2 in Example 1

[0028] Figure 3 XRD diffraction pattern comparison diagram of the materials of Example 1 (BGa-RuO2), Comparative Example 1 (B-RuO2), Comparative Example 2 (Ga-RuO2), and Comparative Example 3 (Home-RuO2) and the standard pdf card.

[0029] Figure 4OER polarization curves of the materials of Example 1 (BGa-RuO2), Comparative Example 1 (B-RuO2), Comparative Example 2 (Ga-RuO2), Comparative Example 3 (Home-RuO2), and commercial RuO2 (Com-RuO2).

[0030] Figure 5 Stability diagram of Example 1 (BGa-RuO2)

[0031] Figure 6 Stability diagram of Comparative Example 3 (Home-RuO2) Specific implementation method

[0033] To further understand the present invention, the technical solutions in the embodiments of the present invention are clearly and completely described. At the same time, the following described examples are only a part of the present invention, not all of it. The following description is only to further illustrate the advantages and features of the present invention, rather than a limitation on the claims of the present invention. Other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0034] The technical solutions of the present invention will be further described below in conjunction with specific examples.

[0035] Example 1

[0036] A ruthenium oxide anode catalyst modified by double doping of boron and gallium, and its preparation method includes the following steps:

[0037] (1) Cut the carbon paper into an area of 1 cm × 2 cm, and then hydrothermally treat the cut carbon paper in diluted concentrated nitric acid (volume ratio of HNO3:H2O is 1:1) at 150 °C for 6 h. After taking it out, ultrasonically treat it in ethanol and water for 30 min in sequence, and then dry it at 70 °C for 6 h to obtain the treated conductive substrate carbon paper.

[0038] (2) Weigh 3 g of glucose and 0.6 g of urea, dissolve them in 10 mL of deionized water, and stir at room temperature until dissolved to obtain a mixed solution A.

[0039] (3) Weigh 30 mg of ruthenium chloride, 36.8 mg of gallium nitrate, and 26 mg of boric acid, dissolve them in 10 mL of deionized water, and stir at room temperature until dissolved to obtain a mixed solution B.

[0040] (4) Mix the mixed solutions A and B evenly, stir at room temperature for 30 min until completely dissolved. Transfer it to a 50 mL hydrothermal autoclave, set the hydrothermal temperature to 160 °C and the hydrothermal time to 8 h to obtain a sol-gel solid precursor.

[0041] (5) The sol solid precursor was centrifugally washed three times with deionized water and anhydrous ethanol respectively. After pouring off the supernatant, the sol solid was dried in a vacuum drying oven at 70 °C for 12 h and then ground into powder in a mortar.

[0042] (6) The powder was sintered in a tube furnace with air as the gas atmosphere to form a black powder. The reaction temperature was set at 400 °C, the heating rate was 5 °C / min, and the sintering time was 12 h to obtain the ruthenium oxide BGa-RuO2 catalyst modified by boron and gallium dual-element doping.

[0043] (7) 5 mg of the obtained BGa-RuO2 catalyst was taken, 460 μL of ethanol was used as the dispersant, and 40 μL of 5 wt% Nafion117 solution was used as the binder to drop-coat the BGa-RuO2 catalyst onto the carbon paper pretreated in (1), and then dried in an oven at 60 °C to obtain the BGa-RuO2 electrode.

[0044] (8) The composite electrode prepared above was used for electrocatalytic oxygen evolution reaction. The specific steps were as follows: A three-electrode system was constructed, where the working electrode was the BGa-RuO2 electrode, the reference electrode was the silver / silver chloride electrode, and the counter electrode was a carbon rod. The OER performance was tested in an oxygen-saturated 0.5 mol / L sulfuric acid solution. The results showed that the BGa-RuO2 only needed an overpotential of 170 mV to reach a current density of 10 mA cm -2 and could maintain for more than 1400 hours without decay.

[0045] Example 2

[0046] A ruthenium oxide anode catalyst modified by boron and aluminum dual-doping, and its preparation method includes the following steps

[0047] (1) The carbon paper was cut into an area of 1 cm × 2 cm, and then the cut carbon paper was hydrothermally treated in diluted concentrated nitric acid (volume ratio of HNO3:H2O is 1:1) at 150 °C for 6 h. After taking it out, it was sonicated in ethanol and water for 30 min in turn, and then dried at 70 °C for 6 h to obtain the treated conductive substrate carbon paper.

[0048] (2) 1.8 g of glucose and 0.15 g of urea were weighed and dissolved in 15 mL of deionized water, and stirred at room temperature until dissolved to obtain a mixed solution A.

[0049] (3) 15 mg of ruthenium chloride, 20 mg of aluminum nitrate and 22 mg of boric acid were weighed and dissolved in 10 mL of deionized water, and stirred at room temperature until dissolved to obtain a mixed solution B.

[0050] (4) Mix the mixed solutions A and B evenly and stir for 30 min at room temperature until completely dissolved. Transfer to a 50 mL hydrothermal autoclave, set the hydrothermal temperature at 180 °C and the hydrothermal time at 12 h to obtain a sol solid precursor.

[0051] (5) Centrifuge and wash the sol solid precursor 4 times with deionized water and absolute ethanol respectively, pour off the supernatant, dry the sol solid in a vacuum drying oven at 50 °C for 6 h, and then grind it into powder in a mortar.

[0052] (6) Sinter the powder in a tubular furnace with air as the gas atmosphere to form a black powder. Set the reaction temperature at 450 °C, the heating rate at 4 °C / min, and the reaction time at 8 h to obtain a ruthenium oxide catalyst BAl-RuO2 modified by dual doping of boron and aluminum.

[0053] (7) Take 5 mg of the obtained BAl-RuO2 catalyst, use 460 μL of ethanol as a dispersant and 40 μL of 5 wt% Nafion117 solution as a binder to drop-coat the catalyst onto the carbon paper pretreated in (1), and dry it in an oven at 60 °C to obtain a BAl-RuO2 electrode.

[0054] (8) Use the composite electrode prepared above for electrocatalytic oxygen evolution reaction. The specific steps are as follows: construct a three-electrode system, where the working electrode is the BAl-RuO2 electrode, the reference electrode is the silver / silver chloride electrode, and the counter electrode is a carbon rod. Test the OER performance in an oxygen-saturated 0.5 mol / L sulfuric acid solution. The results show that the BAl-RuO2 requires an overpotential of 179 mV to reach a current density of 10 mA cm -2 and can maintain for more than 300 hours without decay.

[0055] Example 3

[0056] A ruthenium oxide anode catalyst modified by dual doping of boron and indium, and its preparation method includes the following steps:

[0057] (1) Cut the carbon paper into an area of 1 cm × 2 cm, and then hydrothermally treat the cut carbon paper in diluted concentrated nitric acid (volume ratio of HNO3:H2O is 1:1) at 150 °C for 6 h. Take it out and ultrasonically treat it in ethanol and water for 30 min in turn, and then dry it at 70 °C for 6 h to obtain a treated conductive substrate carbon paper.

[0058] (2) Weigh 4.8 g of glucose and 0.6 g of urea, dissolve them in 20 mL of deionized water, and stir at room temperature until dissolved to obtain solution A.

[0059] (3) Weigh 18 mg of ruthenium chloride, 15 mg of indium nitrate and 13 mg of boric acid, dissolve them in 10 mL of deionized water, and stir at room temperature until dissolved to obtain solution B.

[0060] (4) Mix solutions A and B evenly and stir for 30 min at room temperature until completely dissolved. Transfer to a 50 mL hydrothermal reactor, set the hydrothermal temperature at 100 °C and the hydrothermal time at 6 h to obtain a sol-gel solid precursor.

[0061] (5) Centrifuge and wash the sol-gel solid precursor 5 times with deionized water and anhydrous ethanol respectively, pour off the supernatant, dry the sol-gel solid in a vacuum drying oven at 60 °C for 18 h, and then grind it into powder in a mortar.

[0062] (6) Sinter the powder in a tube furnace with air as the gas atmosphere to form a black powder. Set the reaction temperature at 500 °C, the heating rate at 2 °C / min, and the reaction time at 16 h to obtain a ruthenium oxide BIn-RuO2 catalyst modified by boron and indium dual-element doping.

[0063] (7) Take 5 mg of the obtained BIn-RuO2 catalyst, use 460 μL of ethanol as a dispersant and 40 μL of 5 wt% Nafion117 solution as a binder to drop-coat the catalyst onto the carbon paper pretreated in (1), and dry it in an oven at 60 °C to obtain a BIn-RuO2 electrode.

[0064] (8) Use the composite electrode prepared above for electrocatalytic oxygen evolution reaction. The specific steps are as follows: construct a three-electrode system, where the working electrode is the BIn-RuO2 electrode, the reference electrode is the silver / silver chloride electrode, and the counter electrode is a carbon rod. Test the OER performance in an oxygen-saturated 0.5 mol / L sulfuric acid solution. The results show that the BIn-RuO2 requires an overpotential of 182 mV to reach a current density of 10 mA cm -2 and can maintain for more than 300 hours without attenuation.

[0065] Comparative Example 1

[0066] A ruthenium oxide electrocatalytic electrode modified by B doping, and its preparation method is as follows:

[0067] (1) Cut the carbon paper into an area of 1 cm × 2 cm, and then hydrothermally treat the cut carbon paper in diluted concentrated nitric acid (volume ratio of HNO3:H2O is 1:1) at 150 °C for 6 h. Take it out and ultrasonically treat it in ethanol and water for 30 min in turn, and then dry it at 70 °C for 6 h to obtain the treated conductive substrate carbon paper.

[0068] (2) Weigh 3 g of glucose and 0.6 g of urea, dissolve them in 10 mL of deionized water, and stir at room temperature until dissolved to obtain solution A.

[0069] (3) Weigh 30 mg of ruthenium chloride and 26 mg of boric acid, dissolve them in 10 mL of deionized water, and stir at room temperature until dissolved to obtain solution B.

[0070] (4) Mix solutions A and B evenly and stir for 30 min at room temperature until completely dissolved. Transfer to a 50 mL hydrothermal reactor, set the hydrothermal temperature at 160 °C and the hydrothermal time at 8 h to obtain a sol solid.

[0071] (5) Centrifuge and wash the sol solid three times with deionized water and absolute ethanol respectively, pour off the supernatant, and dry the sol solid in a vacuum drying oven at 70 °C for 12 h.

[0072] (6) Grind the obtained sol solid into powder in a mortar. Sinter in a tubular furnace under an air atmosphere, set the reaction temperature at 400 °C, the heating rate at 5 °C / min, and the reaction time at 12 h to obtain a boron-doped ruthenium oxide B-RuO2 electrocatalyst.

[0073] (7) Take 5 mg of the obtained B-RuO2 catalyst, use 460 μL of ethanol as a dispersant and 40 μL of 5 wt% Nafion117 solution as a binder to drop-coat the B-RuO2 catalyst onto the carbon paper pretreated in (1). Place it in an oven and dry at 60 °C to obtain a B-RuO2 electrode for use.

[0074] (8) Use the composite electrode prepared above for electrocatalytic oxygen evolution reaction. The specific steps are as follows: Construct a three-electrode system, where the working electrode is the B-RuO2 electrode, the reference electrode is the silver / silver chloride electrode, and the counter electrode is a carbon rod. Test the OER performance in an oxygen-saturated 0.5 mol / L sulfuric acid solution.

[0075] Comparative Example 2

[0076] A gallium-doped ruthenium oxide electrocatalytic electrode, and its preparation method is as follows:

[0077] (1) Cut the carbon paper into an area of 1 cm × 2 cm, and then hydrothermally treat the cut carbon paper in diluted concentrated nitric acid (volume ratio of HNO3:H2O is 1:1) at 150 °C for 6 h. Take it out and ultrasonically treat it in ethanol and water for 30 min in sequence, and then dry it at 70 °C for 6 h to obtain a treated conductive substrate carbon paper.

[0078] (2) Weigh 3 g of glucose and 0.6 g of urea, dissolve them in 10 mL of deionized water, and stir at room temperature until dissolved to obtain solution A.

[0079] (3) Weigh 30 mg of ruthenium chloride and 36.8 mg of gallium nitrate, dissolve them in 10 mL of deionized water, and stir at room temperature until dissolved to obtain solution B.

[0080] (4) Mix solutions A and B evenly and stir at room temperature for 30 min until completely dissolved. Transfer to a 50 mL hydrothermal reactor, set the hydrothermal temperature at 160 °C and the hydrothermal time at 8 h to obtain a sol solid.

[0081] (5) Centrifuge and wash the sol solid three times with deionized water and anhydrous ethanol respectively, pour off the supernatant, and dry the sol solid in a vacuum drying oven at 70 °C for 12 h.

[0082] (6) Grind the obtained sol solid into fine powder in a mortar. Sinter in a tubular furnace under an air atmosphere, set the reaction temperature at 400 °C, the heating rate at 5 °C / min, and the reaction time at 12 h to obtain a ruthenium oxide electrocatalyst modified by gallium element doping, Ga-RuO2.

[0083] (7) Take 5 mg of the obtained Ga-RuO2 catalyst, use 460 μL of ethanol as a dispersant, and 40 μL of 5 wt% Nafion 117 solution as a binder to drop-coat the catalyst onto the carbon paper pretreated in (1). Place it in an oven and dry at 60 °C to obtain a Ga-RuO2 electrode for use.

[0084] (8) Use the composite electrode prepared above for electrocatalytic oxygen evolution reaction. The specific steps are as follows: Construct a three-electrode system, where the working electrode is the Ga-RuO2 electrode, the reference electrode is the silver / silver chloride electrode, and the counter electrode is a carbon rod. Test the OER performance in an oxygen-saturated 0.5 mol / L sulfuric acid solution.

[0085] Comparative Example 3

[0086] A porous ruthenium oxide electrocatalytic electrode, and its preparation method is as follows:

[0087] (1) Cut the carbon paper into an area of 1 cm × 2 cm, and then hydrothermally treat the cut carbon paper in diluted concentrated nitric acid (volume ratio of HNO3:H2O is 1:1) at 150 °C for 6 h. Take it out and ultrasonically treat it in ethanol and water for 30 min in sequence, and then dry it at 70 °C for 6 h to obtain a treated conductive substrate carbon paper.

[0088] (2) Weigh 3 g of glucose and 0.6 g of urea, dissolve them in 10 mL of deionized water, and stir at room temperature until dissolved to obtain solution A.

[0089] (3) Weigh 30 mg of ruthenium chloride, dissolve it in 10 mL of deionized water, and stir at room temperature until dissolved to obtain solution B.

[0090] (4) Mix solutions A and B evenly and stir at room temperature for 30 min until completely dissolved. Transfer to a 50 mL hydrothermal reactor, set the hydrothermal temperature at 160 °C and the hydrothermal time at 8 h to obtain a sol solid.

[0091] (5) Centrifuge and wash the sol solids three times with deionized water and anhydrous ethanol respectively. Pour off the supernatant, and dry the sol solids in a vacuum drying oven at 70 °C for 12 h.

[0092] (6) Grind the obtained sol solids into fine powder in a mortar. Sinter in a tubular furnace under an air atmosphere. Set the reaction temperature at 400 °C, the heating rate at 5 °C / min, and the reaction time at 12 h to obtain the self-made porous ruthenium oxide Home-RuO2 catalyst.

[0093] (7) Take 5 mg of the obtained Home-RuO2 catalyst, use 460 μL of ethanol as the dispersant, and 40 μL of 5 wt% Nafion117 solution as the binder to drop-coat the Home-RuO2 catalyst onto the carbon paper pretreated in (1), and place it in an oven at 60 °C for drying to obtain the Home-RuO2 electrode for use.

[0094] (8) Use the above-prepared Home-RuO2 electrode for electrocatalytic oxygen evolution reaction. The specific steps are as follows: Construct a three-electrode system, where the working electrode is the Home-RuO2 electrode, the reference electrode is the silver / silver chloride electrode, and the counter electrode is the carbon rod. Test the OER performance in an oxygen-saturated 0.5 mol / L sulfuric acid solution.

[0095] Figure 1 Figure (14) shows the scanning electron microscope photograph (SEM) of BGa-RuO2 obtained in Example 1. It can be observed that Figure 1 the BGa-RuO2 catalyst is composed of dense nano-spheres with a size of 40 - 60 nm. This structure increases the electrochemically active area of the catalyst, increases the number of active sites, and effectively improves the electrocatalytic performance of the catalyst.

[0096] Figure 2 Figure (20) shows the elemental mapping diagram of BGa-RuO2 obtained in Example 1. It can be seen from the figure that the elements B, Ga, and Ru are successfully incorporated and are evenly distributed in the material.

[0097] Figure 3 Figure (24) shows the X-ray diffraction patterns (XRD) of the electrodes obtained in Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 3. The peaks of the XRD patterns corresponding to the individual doping of B or Ga do not shift compared to those of ruthenium oxide, indicating that the crystal structure of RuO2 has not changed after doping; similarly, the peaks of the XRD pattern of RuO2 modified by the co-doping of B and Ga also do not shift compared to those of ruthenium oxide, indicating that B and Ga exist in an amorphous form or in a smaller form after doping.

[0098] Figure 4The figure shows the electrocatalytic oxygen evolution performance diagrams of the electrodes obtained from Example 1, Comparative Example 1, Comparative Example 2, Comparative Example 3, and commercial RuO2. The OER linear voltammetry images were collected in a 0.5 mol / L sulfuric acid solution at a scanning rate of 5 mV per second. It can be seen from the figure that the overpotentials of BGa-RuO2, B-RuO2, Ga-RuO2, Home-RuO2, and Com-RuO2 at 10 mA cm -2 are 170 mV, 183 mV, 192 mV, 232 mV, and 280 mV respectively. In contrast, the BGa-RuO2 anode electrocatalyst electrode has excellent electrocatalytic oxygen evolution performance. The introduction of boron reduces the crystal configuration of the catalyst. Compared with crystalline substances, the amorphous structure not only provides significant active sites but also actively adjusts the Ru-O bond and optimizes the oxygen intermediate adsorption energy, thus achieving a significant improvement in activity. On the other hand, the electronic spatial regulation of B optimizes the bimetallic synergistic effect between the doped metal element and Ru. The common synergy between the non-metal B and the doped metal element optimizes the catalytic activity of RuO2. After doping, the dissolution effect of Ru is inhibited, effectively improving the acid resistance of RuO2 during the OER process and improving its stability. The BGa-RuO2 anode only requires an overpotential of 170 mV to reach a current density of 10 mA cm -2 . It has excellent OER performance.

[0099] Figure 6 The figure shows the chronoamperometric stability diagram of Home-RuO2 at a current density of 10 mA cm -2 . It can be seen that Home-RuO2 can be stable for about 120 h. After that, the overpotential rises steeply and loses its activity. Figure 5 The figure shows the chronoamperometric stability diagram of BGa-RuO2 at a current density of 10 mA cm -2 . It can be obtained that it can maintain a stability of more than 1400 h, and the overpotential only increases by about 100 mV, proving that its OER stability in acidic media is very excellent. For other bimetal-doped ruthenium oxide electrodes such as InSnRuO2, its overpotential at 10 mA cm -2 is 183 mV and it can operate stably for 200 h. Compared with the BGa-RuO2 anode, it has greatly improved catalytic activity and stability, and has the value of replacing Ir-based catalysts for large-scale commercial applications.

[0100] The above embodiments only represent the implementation modes of the present invention, but should not be construed as limiting the scope of the patent of the present invention. It should be noted that for those skilled in the art, without departing from the concept of the present invention, several deformations and improvements can be made, and these all belong to the protection scope of the present invention.

Claims

1. A boron and metal doped ruthenium oxide anode catalyst, characterized in that: The anode catalyst has a compact nanosphere shape with a size of 40-60 nm, wherein the molar ratio of boron, doping metal and ruthenium is (3-3.3):(3-0.2):

1.

2. The method for preparing a boron-metal dual-doped ruthenium oxide anode catalyst according to claim 1, characterized in that: The preparation method comprises the following steps: Step 1, weigh a certain amount of glucose and urea, dissolve them in deionized water, and stir until they are completely dissolved to obtain a mixed solution A; Step 2, weighing a certain amount of ruthenium chloride, nitrate hydrate and boric acid, dissolving them in deionized water, and stirring until they are completely dissolved to obtain a mixed solution B; Step 3, mixing the mixed solution A and the mixed solution B evenly, stirring until they are completely dissolved, to obtain a precursor mixed solution C; Step 4, placing the precursor solution C in a hydrothermal kettle, performing a hydrothermal operation in an oven, and obtaining a gel solid precursor after washing; Step 5, drying the obtained gel solid precursor in a vacuum drying oven, and grinding the obtained solid product into powder; Step 6, sintering the powder in a tube furnace with air as the gas atmosphere to form a black powder, and cooling it to room temperature to obtain a boron-and metal-doped ruthenium oxide anode catalyst.

3. The method for preparing a boron-metal dual-doped ruthenium oxide anode catalyst according to claim 2, characterized in that: In the step 1, the concentrations of glucose and urea in the mixed solution A are 0.4-1 mol / L and 0.1-0.6 mol / L, respectively.

4. The method for preparing a boron-metal dual-doped ruthenium oxide anode catalyst according to claim 2, characterized in that: In the step 2, the concentrations of ruthenium chloride, nitrate hydrate and boric acid in the mixed solution B are 0.05-0.1 mol / L, 0.02-0.15 mol / L and 0.15-0.33 mol / L, respectively, wherein the nitrate hydrate is gallium nitrate hydrate, indium nitrate hydrate or aluminum nitrate hydrate.

5. The method for preparing a boron and metal dual-doped ruthenium oxide anode catalyst according to claim 4, characterized in that: The nitrate hydrate is gallium nitrate hydrate.

6. The method for preparing a boron-metal dual-doped ruthenium oxide anode catalyst according to claim 2, characterized in that: In step 3, the volume ratio of mixed solution A to mixed solution B is 1:1-2:

1.

7. The method for preparing a boron-metal dual-doped ruthenium oxide anode catalyst according to claim 2, characterized in that: In the step 4, the hydrothermal temperature is 100-180° C., the hydrothermal time is 6-12 hours, and after the hydrothermal process, the mixture is washed in a centrifuge with anhydrous ethanol and deionized water for 3-5 times in sequence until the upper layer of liquid is clear and transparent.

8. The method for preparing a boron-metal dual-doped ruthenium oxide anode catalyst according to claim 2, characterized in that: In step 6, the sintering process is: heating to 400-500°C at a heating rate of 2-5°C / min and keeping the temperature for 8-16h.

9. The use of a boron and metal dual-doped ruthenium oxide anode catalyst according to claim 1, characterized in that: Used in water electrolysis to produce hydrogen.

10. The use of a boron and metal dual-doped ruthenium oxide anode catalyst according to claim 9, characterized in that: The specific process of hydrogen production by electrolysis of water is as follows: using the prepared boron and metal dual-doped ruthenium oxide anode catalyst as the working electrode, the Ag / AgCl electrode as the reference electrode, and the carbon rod as the counter electrode, an acidic electrolysis of water and oxygen evolution reaction are carried out in an oxygen-saturated 0.5 mol / L sulfuric acid solution.

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