Selenium-doped ruthenium dioxide as well as preparation method and application thereof

Abstract

The invention discloses selenium-doped ruthenium dioxide and a preparation method and application thereof.Ruthenium trichloride and sodium selenite are dissolved in an alcohol solvent and then placed in an oil bath pan to react, a reacted sample is washed, loaded, dried and calcined, and finally selenium-doped ruthenium dioxide is successfully prepared. The prepared ruthenium dioxide is in a porous cluster shape, more active sites can be exposed, the activity and stability of the ruthenium dioxide are improved by regulating electron transfer through selenium doping and inducing reaction mechanism transformation, and the ruthenium dioxide shows excellent oxygen evolution performance when serving as a catalyst to be used for hydrogen production through water electrolysis and has application prospects in the field of electrocatalysis.

Description

Technical Field

[0001] This invention relates to the field of electrochemical energy materials, specifically to a selenium-doped ruthenium dioxide, its preparation method, and its applications. Technical Background

[0002] Ruthenium dioxide, as a typical transition metal oxide functional material, is widely used in electrocatalysis, electrochemical energy storage, chlor-alkali industry electrodes and other fields due to its excellent electronic conductivity, high electrochemical activity and good chemical stability. It is one of the current research hotspots in the energy and chemical industry.

[0003] However, pure-phase ruthenium dioxide still has technical drawbacks in practical applications: First, under long-term electrochemical conditions, its crystal structure is prone to collapse and particle agglomeration, leading to rapid decay of active sites and poor electrochemical stability; Second, the specific surface area and active site exposure of pure-phase ruthenium dioxide are limited, making it difficult to further improve its catalytic activity or energy storage capacity.

[0004] To overcome these shortcomings, existing technologies mostly employ elemental doping modification strategies, adjusting the electronic structure of ruthenium dioxide and optimizing its surface morphology to enhance its performance. Currently, mainstream preparation methods generally suffer from drawbacks: wet chemical methods require high-pressure reactors under harsh conditions of high temperature and pressure, resulting in high costs for specialized equipment, high operational risks, and long reaction cycles; while thin film preparation technologies such as physical vapor deposition and chemical vapor deposition can obtain products with high purity, they rely on high-vacuum systems, plasma generators, and other precision equipment, leading to high costs and low yields.

[0005] Chinese patent document CN 111215098 A discloses a selenized surface-modified ruthenium dioxide nanoparticle catalyst, its preparation method, and its application. Using carbon black as a carrier, ruthenium dioxide is first fixed onto the carrier through grinding; then, selenium is modified onto the surface of the ruthenium dioxide nanoparticles through high-temperature calcination. This prior art, by processing the nanoparticles, uses 2 to 15 times the amount of selenium powder, resulting in significant raw material waste and pollution. It also uses easily explosive raw materials such as sodium borohydride, making it environmentally unfriendly.

[0006] Therefore, it is necessary to propose a selenium-doped ruthenium dioxide and its preparation method and application, which is environmentally friendly, does not require harsh equipment such as high pressure and high vacuum, and has simple and controllable operation steps, which can effectively reduce the investment in production equipment and time costs. At the same time, by optimizing the doping ratio of elements, the obtained selenium-doped ruthenium dioxide has better electrochemical activity than the products of traditional simple processes. Summary of the Invention

[0007] To address the problems existing in the prior art, the present invention aims to provide a selenium-doped ruthenium dioxide, its preparation method, and its applications. This preparation method eliminates the need for demanding equipment such as high pressure and high vacuum, and the operation steps are simple and controllable, effectively reducing investment in production equipment and time costs. Furthermore, by optimizing the doping ratio of elements, the resulting selenium-doped ruthenium dioxide exhibits superior electrochemical activity compared to products from traditional simple processes.

[0008] To address the aforementioned technical problems, a first aspect of the present invention provides a method for preparing selenium-doped ruthenium dioxide, comprising the following steps:

[0009] S1. Weigh ruthenium trichloride and sodium selenite and dissolve them in an alcohol solvent. Mix them evenly by ultrasonication to obtain a precursor solution.

[0010] S2. Transfer the precursor solution to the reaction vessel and place it in an oil bath for reaction. After the reaction is completed and cooled to room temperature, perform multiple washing and centrifugation purification processes to obtain the purified sample.

[0011] S3. Disperse the carrier in an ethanol solution, add the purified sample, mix thoroughly by ultrasonication, centrifuge again to collect the precipitate, and dry the precipitate to obtain a powder sample.

[0012] S4. Place the powdered sample in a muffle furnace and calcine to obtain selenium-doped ruthenium dioxide.

[0013] This invention discloses a method for preparing selenium-doped ruthenium dioxide, successfully producing selenium-doped ruthenium dioxide without requiring demanding equipment such as high pressure and high vacuum. By loading the post-reaction sample onto a carbon support, particle agglomeration can be avoided, increasing the specific surface area and thus exposing more active sites. Simultaneously, the excellent conductivity of carbon materials accelerates charge transfer between active sites and the external circuit, increasing the reaction rate. Furthermore, by utilizing the difference in electronegativity between selenium and ruthenium, electron transfer is modulated, optimizing the adsorption energy of oxygen evolution reaction (OER) intermediates, lowering the reaction energy barrier, and enhancing catalytic activity. The introduction of selenium induces a change in the reaction mechanism, thereby improving catalytic stability.

[0014] Preferably, the mass ratio of ruthenium trichloride to sodium selenite in step S1 is 1:0.5 to 1:2.

[0015] Preferably, the alcohol solvent in step S1 is one of ethylene glycol, propylene glycol, glycerol, and polyethylene glycol, and the ruthenium trichloride concentration is 1 mg / mL to 5 mg / mL.

[0016] Preferably, in step S2, the reaction temperature is 160~200°C, and the reaction time is 1~10h. The washing solvent is ethanol, the centrifugation time is 2~5min, the rotation speed is 10000~12000rpm, and the process is repeated at least twice.

[0017] Preferably, the carrier in step S3 is one of carbon black, carbon nanotubes, or porous carbon; the drying temperature is 60~80°C, and the drying time is 6~24h.

[0018] Preferably, in step S4, the calcination temperature is 350~700°C, the heating rate is 10°C / min, and the calcination time is 2~8h.

[0019] A second aspect of the present invention is to provide selenium-doped ruthenium dioxide prepared by the preparation method described in the first aspect of the present invention.

[0020] The selenium-doped ruthenium dioxide prepared by this invention has excellent electrocatalytic OER activity.

[0021] A third aspect of the present invention is to provide the application of selenium-doped ruthenium dioxide as a catalyst in the electrolysis of water to produce hydrogen, as described in the second aspect of the present invention.

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

[0023] (1) This invention uses ruthenium trichloride and sodium selenite as raw materials to replace the high-cost organic selenium source in traditional processes. The raw material cost is lower and the supply is stable. It is also environmentally friendly as it does not use flammable raw materials. The resulting selenium-doped ruthenium dioxide exhibits a porous cluster morphology, which can expose more active sites and has excellent electrocatalytic OER activity.

[0024] (2) The present invention adopts the solvothermal method, which does not require harsh equipment such as high pressure and high vacuum. It has the characteristics of simple process steps, easy safety and control, less chemical reagents used in the entire preparation process, less environmental pollution, environmental friendliness, mild experimental conditions and short time consumption; it effectively reduces the investment and time cost of production equipment and is suitable for large-scale industrial production.

[0025] (3) The selenium-doped ruthenium dioxide prepared in this invention utilizes the difference in electronegativity between selenium and ruthenium to regulate electron transfer, thereby lowering the reaction energy barrier of OER and enhancing catalytic activity. The introduction of selenium induces a change in the reaction mechanism, thus improving catalytic stability.

[0026] (4) By optimizing key parameters such as the mass ratio of ruthenium trichloride to sodium selenite, reaction temperature, reaction time, and calcination temperature, the resulting selenium-doped ruthenium dioxide exhibits superior electrochemical activity compared to products from traditional simple processes. When the selenium-doped ruthenium dioxide prepared in this invention is used as an oxygen evolution catalyst for water electrolysis to produce hydrogen, it demonstrates excellent oxygen evolution performance at 10 mA / cm². -2 It achieves an overpotential of only 212mV at a current density, while also exhibiting good stability. Attached Figure Description

[0027] Figure 1 The images show the SEM morphology and EDS spectrum of selenium-doped ruthenium dioxide in specific embodiment 1 of the present invention; where (a) is the SEM morphology and (b) is the EDS spectrum.

[0028] Figure 2 The OER performance comparison curves and stability curves of selenium-doped ruthenium dioxide as a catalyst in Specific Example 1 of the present invention are shown; where (a) is the OER performance comparison curve of the three catalysts; and (b) is the stability curve of the catalyst prepared in Specific Example 1.

[0029] Figure 3 The XRD spectra of ruthenium dioxide catalysts with different selenium doping ratios (specific examples 1, 4-5) and comparative examples in this invention are shown.

[0030] Figure 4 The OER performance curves of ruthenium dioxide catalysts with different selenium doping ratios (specific examples 1, 4-5) in this invention are shown.

[0031] Figure 5 The OER performance curves of ruthenium dioxide catalysts prepared at different temperatures with the same selenium doping ratio in this invention (specific examples 1 and 6-7) are shown. Detailed Implementation

[0032] To make the technical problem to be solved, the technical solution, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0033] Example: The preparation method of this selenium-doped ruthenium dioxide includes the following steps:

[0034] S1. Weigh ruthenium trichloride and sodium selenite and dissolve them in an alcohol solvent. Sonicate the mixture for 15 minutes at room temperature to obtain a precursor solution. In step S1, the mass ratio of ruthenium trichloride to sodium selenite is 1:0.5 to 1:2. The alcohol solvent is one of ethylene glycol, propylene glycol, glycerol, or polyethylene glycol. The mass concentration of ruthenium trichloride is 1 mg / mL to 5 mg / mL.

[0035] In some specific embodiments, in step S1, the mass of ruthenium trichloride is 16 mg, the mass of sodium selenite is 14~26.6 mg, and the volume of ethylene glycol is 10 mL;

[0036] S2. Transfer the precursor solution to the reaction vessel and place it in an oil bath for reaction. After the reaction is completed and cooled to room temperature, perform multiple washing and centrifugation purification processes to obtain the purified sample.

[0037] In step S2, the reaction temperature is 160~200°C, the reaction time is 1~10h; the washing solvent is ethanol, the centrifugation time is 2~5min, the speed is 10000~12000rpm, and it is repeated at least twice.

[0038] S3. Disperse the carrier in an ethanol solution, add the purified sample, mix thoroughly by ultrasonication, centrifuge again to collect the precipitate, and dry the precipitate to obtain a powder sample.

[0039] In step S3, the carrier is one of carbon black, carbon nanotubes, or porous carbon; the drying temperature is 60-80°C, and the drying time is 6-24 hours.

[0040] S4. Place the sample in a muffle furnace for calcination at a temperature of 350~700°C, a heating rate of 10°C / min, and a calcination time of 2~8h to obtain selenium-doped ruthenium dioxide.

[0041] The selenium-doped ruthenium dioxide was prepared by the method of the present invention.

[0042] In this embodiment of the invention, the application of the selenium-doped ruthenium dioxide as a catalyst is the application of the selenium-doped ruthenium dioxide prepared by the method of this invention as a catalyst in the electrolysis of water to produce hydrogen.

[0043] In some specific embodiments, the selenium-doped ruthenium dioxide is used as a catalyst in the anode of an acidic water electrolysis hydrogen production device.

[0044] The following detailed description is based on several specific embodiments.

[0045] Specific Example 1: The preparation method of selenium-doped ruthenium dioxide, wherein the Se doping amount is 14.5 at%, is characterized by the following steps:

[0046] S1. Weigh 16 mg of ruthenium trichloride and 20 mg of sodium selenite and dissolve them in 10 mL of ethylene glycol solvent. Mix them evenly by sonication for 15 min to obtain the precursor solution.

[0047] S2. Transfer the precursor solution to the reaction vessel and place it in an oil bath at 200°C for 5 hours. After the reaction is complete and cooled to room temperature, transfer the solution to a centrifuge tube, add ethanol, and centrifuge the sample for 3 minutes at 12,000 rpm. Repeat twice.

[0048] S3. Disperse 20 mg of carbon black in an ethanol solution, add the washed sample, sonicate for 15 min to mix evenly, centrifuge again to collect the precipitate, and place the precipitate in a drying oven at 60°C for 12 h to obtain a powder sample.

[0049] S4. The sample was placed in a muffle furnace and calcined at 400°C for 2 hours to obtain selenium-doped ruthenium dioxide nanopowder.

[0050] Specific Embodiment 2: The difference from Specific Embodiment 1 is that the mass of sodium selenite in step S1 is 14 mg.

[0051] Specific embodiment 3: The difference from specific embodiment 1 is that the mass of sodium selenite in step S1 is 16.7 mg.

[0052] Specific embodiment 4: The difference from specific embodiment 1 is that the mass of sodium selenite in step S1 is 23.3 mg.

[0053] Specific embodiment 5: The difference from specific embodiment 1 is that the mass of sodium selenite in step S1 is 26.6 mg.

[0054] Specific Embodiment 6: The difference from Specific Embodiment 1 is that the calcination temperature in step S4 is 350°C.

[0055] Specific Embodiment 7: The difference from Specific Embodiment 1 is that the calcination temperature in step S4 is 450°C.

[0056] Comparative Example: The difference from Specific Example 1 is that no calcination is performed, and the dried powder is used directly as a catalyst.

[0057] Structural characterization and performance analysis were performed on the above specific embodiments 1 to 7.

[0058] Figure 1 The images show the SEM morphology and EDS energy dispersive spectroscopy of selenium-doped ruthenium dioxide in specific embodiment 1 of this invention; from... Figure 1 The SEM image in (a) shows that selenium-doped ruthenium dioxide exhibits a porous, clustered nanostructure, which exposes more active sites. Figure 1 The EDS spectrum in (b) shows that the selenium doping content is 14.5 at.

[0059] To further verify the practical application effect of the selenium-doped ruthenium dioxide catalyst prepared in this invention, it was applied to the anode of an acidic water electrolysis hydrogen production device to conduct water electrolysis hydrogen production experiments. Figure 2 The figures show the OER performance comparison curves and stability curves of selenium-doped ruthenium dioxide as a catalyst in Specific Example 1 of this invention, compared with those of commercial iridium dioxide and commercial ruthenium dioxide; from Figure 2 The (a) OER performance comparison curves show that selenium-doped ruthenium dioxide at 10 mA cm⁻¹ -2With an overpotential of only 212 mV, it exhibits excellent catalytic performance, with activity far exceeding that of commercial ruthenium dioxide and iridium dioxide. Furthermore, the stability of the selenium-doped ruthenium dioxide catalyst prepared in this invention was tested. Figure 2 As can be seen from (b) in the figure, the catalyst can operate stably for 180 hours without significant degradation.

[0060] The performance test comparison analysis above shows that the introduction of selenium, by utilizing the difference in electronegativity between selenium and ruthenium to regulate electron transfer, lowers the reaction energy barrier of OER and enhances catalytic activity. Furthermore, it induces a change in the reaction mechanism, thereby improving catalytic stability.

[0061] Figure 3 The images show the XRD patterns of ruthenium dioxide catalysts with different selenium doping ratios (specific examples 1, 4-5) and comparative examples used in this invention. Figure 3 It can be seen that the comparative example is an amorphous structure. The diffraction peaks that appear in the example at 2θ angles of 28.1°, 35.1°, and 54.3° correspond to the (110), (101), and (211) crystal planes of ruthenium dioxide, respectively. This indicates that the present invention successfully synthesized ruthenium dioxide and no RuSe2 impurity phase appeared, which means that Se entered the RuO2 lattice in the form of doping.

[0062] Figure 4 The OER performance curves of ruthenium dioxide catalysts with different selenium doping ratios (specific examples 1, 4-5) used in this invention are shown. Figure 4 It can be seen that ruthenium dioxide with different selenium doping ratios all have good activity, but the activity will decrease slightly as the selenium doping content increases.

[0063] Figure 5 The OER performance curves of ruthenium dioxide catalysts prepared with the same selenium doping ratio at different calcination temperatures (specific examples 1 and 6-7) in this invention are shown. Figure 5 As can be seen, under the same selenium doping ratio, the OER performance of ruthenium dioxide catalysts prepared at different calcination temperatures varies. Specific Example 1 (calcined at 400°C) exhibits relatively optimal activity, while Specific Example 6 (calcined at 350°C) shows slightly lower activity, and Specific Example 7 (calcined at 450°C) shows a significant decrease in activity. This indicates that the calcination annealing temperature should not be too high. This can be attributed to the fact that excessively high temperatures cause ruthenium dioxide agglomeration, reducing the electrochemical active area of ​​the catalyst and thus severely degrading its catalytic performance.

[0064] For those skilled in the art, the specific embodiments are merely illustrative descriptions of the present invention. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution, such as changing the mass of a substance or a reaction parameter, or directly applying the inventive concept and technical solution to other situations without modification, are all within the protection scope of the present invention.

Claims

1. A method for preparing selenium-doped ruthenium dioxide, characterized in that, Specifically, the following steps are included: S1. Weigh ruthenium trichloride and sodium selenite and dissolve them in an alcohol solvent. Mix them evenly by ultrasonication to obtain a precursor solution. S2. Transfer the precursor solution to the reaction vessel and place it in an oil bath for reaction. After the reaction is completed and cooled to room temperature, perform multiple washing and centrifugation purification processes to obtain the purified sample. S3. Disperse the carrier in an ethanol solution, add the purified sample, mix thoroughly by ultrasonication, centrifuge again to collect the precipitate, and dry the precipitate to obtain a powder sample. S4. Place the powdered sample in a muffle furnace and calcine to obtain selenium-doped ruthenium dioxide.

2. The method for preparing selenium-doped ruthenium dioxide according to claim 1, characterized in that, In step S1, the mass ratio of ruthenium trichloride to sodium selenite is 1:0.5 to 1:

2.

3. The method for preparing selenium-doped ruthenium dioxide according to claim 2, characterized in that, In step S1, the alcohol solvent is one of ethylene glycol, propylene glycol, glycerol, or polyethylene glycol, and the mass concentration of ruthenium trichloride is 1 mg / mL to 5 mg / mL.

4. The method for preparing selenium-doped ruthenium dioxide according to claim 1, characterized in that, In step S2, the reaction temperature is 160~200°C, the reaction time is 1~10h, the washing solvent is ethanol, the centrifugation time is 2~5min, the speed is 10000~12000rpm, and it is repeated at least twice.

5. The method for preparing selenium-doped ruthenium dioxide according to claim 1, characterized in that, In step S3, the carrier is one of carbon black, carbon nanotubes, or porous carbon; the drying temperature is 60-80°C, and the drying time is 6-24 hours.

6. The method for preparing selenium-doped ruthenium dioxide according to claim 1, characterized in that, In step S4, the calcination temperature is 350~700°C, the heating rate is 10°C / min, and the calcination time is 2~8h.

7. A selenium-doped ruthenium dioxide prepared by the preparation method according to any one of claims 1-6.

8. An application of the selenium-doped ruthenium dioxide as described in claim 7 as a catalyst in the electrolysis of water to produce hydrogen.

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