Rare earth element doped ruthenium dioxide electrocatalyst as well as preparation method and application thereof

Abstract

The invention relates to a rare earth element doped ruthenium dioxide electrocatalyst as well as a preparation method and application thereof. The chemical general formula of the rare earth element doped ruthenium dioxide electrocatalyst is RExRu1-xO2, wherein RE comprises any one or a combination of at least two of Sc, Y or lanthanide elements, and x is greater than 0 and less than or equal to 0.5. The rare earth element-doped ruthenium dioxide electrocatalyst provided by the invention has a complete rutile structure, rare earth elements are uniformly doped into ruthenium dioxide crystal lattices, the electronic structure of ruthenium dioxide is changed through rare earth doping, and the electron orbital structure of rare earth shows excellent electron transmission capability; and the charge transfer in the reaction process can be accelerated, and the energy barrier is reduced, so that the catalytic activity and Faraday efficiency of the catalyst are improved.

Description

Technical Field

[0001] The present invention relates to the field of electrocatalysis technology, and in particular to a rare earth element-doped ruthenium dioxide electrocatalyst, a preparation method thereof, and uses thereof. Background Art

[0002] With the rapid development of global energy transition and green chemical technologies, electrochemical catalysis technology is becoming increasingly important in industrial electrolysis, clean energy conversion, and environmental governance. The chlorine evolution reaction (CER), a core electrochemical process in the chlor-alkali industry, directly impacts the production efficiency and energy consumption of basic chemical raw materials such as chlorine and sodium hydroxide.

[0003] In traditional industry, ruthenium dioxide is considered one of the most important catalysts for the chlorine evolution reaction due to its excellent electrocatalytic activity and relatively low cost. However, under the harsh operating conditions of strong acidity, high oxidation potential, and corrosion by active chlorine species, ruthenium dioxide generally faces bottlenecks such as active component dissolution, surface reconstruction deactivation, and insufficient long-term stability, which seriously restrict the improvement of electrolysis device energy efficiency and the optimization of operating costs. Therefore, the design and preparation of more active ruthenium dioxide-based chlorine evolution electrocatalysts is key to promoting the development of the chlor-alkali industry.

[0004] Currently, the most common CER catalyst is the dimensionally stable anode (DSA), which mainly uses oxides of precious metals Ir or Ru as active centers and a Ti-based metal plate as a conductive substrate. In order to save operating costs, many studies have developed DSA materials based on precious metal mixed metal oxides to reduce the precious metal loading.

[0005] In recent years, optimizing the electronic structure and corrosion resistance of ruthenium dioxide catalysts through strategies such as nanostructure design, carrier interface regulation, and heterogeneous atom doping has become a research hotspot in the field of electrocatalytic materials. Element doping, with its short preparation cycle, strong process compatibility, and clear mechanism of action, has become a more promising optimization approach.

[0006] CN110129821A discloses a method for preparing a tin- and antimony-doped titanium-based ruthenium dioxide coating electrode, comprising the following steps: (1) pre-treating a titanium substrate to obtain a pre-treated titanium substrate; (2) coating the surface of the pre-treated titanium substrate described in step (1) with a ruthenium-containing coating solution (A), drying, then coating the surface with a sol-gel coating solution (B), drying, thermally oxidizing, and cooling; repeating the above steps, keeping the solution warm after the final drying, and then cooling to obtain the tin- and antimony-doped titanium-based ruthenium dioxide coating electrode. The present invention enables TiO2 and SnO2, which have similar lattice parameters, to be tightly combined. The prepared tin- and antimony-doped titanium-based ruthenium dioxide coating electrode has better catalytic activity for inhibiting oxygen evolution and promoting chlorine evolution, and can be used as a chlorine evolution anode in the chlor-alkali industry. However, the preparation method is relatively cumbersome and costly.

[0007] Rare earth elements can theoretically significantly alter the electronic structure of ruthenium dioxide. Furthermore, their electron orbital structure exhibits excellent electron transport capabilities, further accelerating charge transfer during the reaction while lowering the energy barrier. Based on the theory of hard and soft acids and bases, the applicants discovered that the strong coordination tendency of rare earth ions (hard acids) and chloride ions (hard bases) further imparts a corrosion-resistant advantage to the material.

[0008] The chlorine evolution Faraday efficiency of ruthenium dioxide electrocatalysts in the existing technology is too low. Therefore, how to develop a ruthenium dioxide-based chlorine evolution electrocatalyst with high catalytic activity and Faraday efficiency and its preparation method has become a problem that needs to be solved urgently. Summary of the Invention

[0009] In order to solve the above technical problems, the purpose of the present invention is to provide a rare earth element doped ruthenium dioxide electrocatalyst and its preparation method and use. The rare earth element doped ruthenium dioxide electrocatalyst of the present invention has a rutile structure and a high chlorine evolution Faraday efficiency.

[0010] To achieve this object, the present invention adopts the following technical solutions:

[0011] In the first aspect, the present invention provides a rare earth element doped ruthenium dioxide electrocatalyst having the general chemical formula RE x Ru 1-x O2; wherein RE includes any one or a combination of at least two of Sc, Y or lanthanide elements, typical but non-limiting combinations include a combination of Sc and Y, a combination of Sc and La, a combination of La and Ce, a combination of Sc, Y and La, a combination of Nd and Sm, a combination of Sc, Y and La, a combination of Er, Tm and Ho, a combination of Pm, Gd, Eu, Tb and Dy, or a combination of Tm, Yb, Lu and Nd.

[0012] 0<x≤0.5, for example, it can be 0.1, 0.2, 0.3, 0.4 or 0.5, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0013] The rare earth element-doped ruthenium dioxide electrocatalyst provided by the present invention has a complete rutile structure and the rare earth elements are uniformly doped into the ruthenium dioxide lattice. The electronic structure of ruthenium dioxide is changed by rare earth doping, and the electronic orbital structure of the rare earth exhibits excellent electron transport ability, which can accelerate the charge transfer in the reaction process while reducing the energy barrier, thereby improving the catalytic activity and Faraday efficiency of the catalyst.

[0014] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the technical objectives and beneficial effects of the present invention can be better achieved and realized.

[0015] Preferably, 0<x≤0.3.

[0016] In a second aspect, the present invention provides a method for preparing the rare earth element-doped ruthenium dioxide electrocatalyst as described in the first aspect, the preparation method comprising the following steps:

[0017] A ruthenium source, a rare earth element source, a solvent and a dispersant are mixed, reacted and annealed to obtain a rare earth element-doped ruthenium dioxide electrocatalyst.

[0018] The present invention utilizes a modified sol-gel method, which facilitates the formation of a uniform and ordered lattice structure. Hydrated rare earth chlorides are used as raw materials to generate a precursor through reaction, followed by annealing to obtain a rare earth element-doped ruthenium dioxide electrocatalyst. The preparation method is simple and low-cost, compatible with existing production processes and equipment, and suitable for large-scale production applications.

[0019] Preferably, the molar ratio of the metal elements contained in the ruthenium source and the rare earth element source is (9-1):1, for example, it can be 9:1, 8:1, 7:1, 6:1, 5:1, 4:1, 3:1, 2:1 or 1:1, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0020] The present invention further controls the molar ratio of the metal elements contained in the ruthenium source and the rare earth element source to be (9-1):1. This molar ratio directly affects the chemical composition of the final rare earth element-doped ruthenium dioxide electrocatalyst. When the proportion of the rare earth element source increases, due to the larger size of the rare earth ions, rare earth oxide impurities may appear in the product, affecting the chlorine evolution activity.

[0021] Preferably, the ruthenium source comprises ruthenium trichloride and / or a hydrate of ruthenium trichloride.

[0022] Preferably, the rare earth element source includes rare earth chloride and / or rare earth chloride hydrate.

[0023] The choice of chloride in the present invention is based on the theory of hard and soft acids and bases. The strong coordination tendency of rare earth ions (hard acids) and chloride ions (hard bases) can further give the material an advantage in corrosion resistance. At the same time, to avoid the introduction of other elements, chlorides are used as raw materials for all metal elements.

[0024] Preferably, the solvent comprises ethanol.

[0025] Compared with the traditional method of using water as a solvent, the present invention uses ethanol as a solvent, which can significantly improve the solubility of the raw materials and more easily induce solvation, thereby improving the uniformity of the doping elements and being more conducive to increasing the doping amount to improve the catalytic activity of the catalyst.

[0026] Preferably, the dispersant comprises a PVP solution.

[0027] Preferably, the reaction temperature is 70°C-90°C, for example, 70°C, 75°C, 80°C, 85°C or 90°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0028] Preferably, the reaction time is 6 h-10 h, for example, 6 h, 7 h, 8 h, 9 h or 10 h, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0029] Preferably, the annealing temperature is 350°C-450°C, for example, 350°C, 380°C, 400°C, 420°C or 450°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0030] Preferably, the heating rate of the annealing is 5°C / min-10°C / min, for example, it can be 5°C / min, 6°C / min, 7°C / min, 8°C / min, 9°C / min or 10°C / min, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0031] Preferably, the annealing time is 150 min-300 min, for example, 150 min, 180 min, 200 min, 220 min, 250 min, 280 min or 300 min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0032] The purpose of annealing in this invention is to initiate a solid-phase reaction. The annealing temperature affects whether the doping element can successfully incorporate into the lattice of the ruthenium dioxide catalyst. If the annealing temperature is too low, the rare earth element-doped ruthenium dioxide electrocatalyst cannot be successfully formed. Furthermore, the annealing temperature is also related to crystal growth. Excessively high temperatures can cause the material to agglomerate and the grain size to be too large, affecting the electrocatalytic activity.

[0033] As a preferred technical solution of the preparation method of the present invention, the preparation method comprises the following steps:

[0034] The ruthenium source, rare earth element source and ethanol were mixed in a molar ratio of the metal elements of (9-1):1, ultrasonicated for 10 min-30 min, PVP solution dispersant was added, and the mixture was reacted in an oil bath at 70°C-90°C for 6 h-10 h. After drying, the mixture was heated to 350°C-450°C at a heating rate of 5°C / min-10°C / min and annealed for 150 min-300 min to obtain a rare earth element-doped ruthenium dioxide electrocatalyst.

[0035] In a third aspect, the present invention provides a use of a rare earth element-doped ruthenium dioxide electrocatalyst as described in the first aspect, wherein the rare earth element-doped ruthenium dioxide electrocatalyst is used for a chlorine evolution reaction.

[0036] The rare earth element-doped ruthenium dioxide electrocatalyst provided by the present invention has a high chlorine evolution Faraday efficiency and higher catalytic activity for chlorine evolution reaction, and has great application prospects in the chlor-alkali industry.

[0037] The numerical range described in the present invention includes not only the point values ​​listed above, but also any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0038] Compared with the prior art, the present invention has at least the following beneficial effects:

[0039] (1) The rare earth element-doped ruthenium dioxide electrocatalyst provided by the present invention has a complete rutile structure and the rare earth elements are uniformly doped into the ruthenium dioxide lattice. The electronic structure of ruthenium dioxide is changed by rare earth doping. The electronic orbital structure of the rare earth exhibits excellent electron transport ability, which can accelerate the charge transfer in the reaction process while reducing the energy barrier, thereby improving the catalytic activity and Faraday efficiency of the catalyst.

[0040] (2) The present invention adopts a modified sol-gel method, which is conducive to the formation of a uniform and ordered lattice structure. Hydrated rare earth chloride is used as a raw material to generate a precursor through reaction, and then annealing treatment is performed to obtain a rare earth element-doped ruthenium dioxide electrocatalyst. The preparation method of the present invention is simple and low-cost, matches existing production process equipment, and is suitable for large-scale production applications.

[0041] (3) The rare earth element-doped ruthenium dioxide electrocatalyst provided by the present invention has a higher chlorine evolution Faraday efficiency and higher catalytic activity for chlorine evolution reaction, and has great application prospects in the chlor-alkali industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 Sc prepared in Example 1 of the present invention 0.1 Ru 0.9 XRD pattern of O2;

[0043] Figure 2 Sc prepared in Example 1 of the present invention 0.1 Ru 0.9 HRTEM image of O2;

[0044] Figure 3 Sc prepared in Example 1 of the present invention 0.1 Ru 0.9 EDS diagram of O2;

[0045] Figure 4 Y prepared in Example 2 of the present invention 0.15 Ru 0.85 XRD pattern of O2;

[0046] Figure 5 It is La prepared in Example 3 of the present invention 0.2 Ru 0.8 XRD pattern of O2;

[0047] Figure 6 This is the HRTEM image of RuO2 prepared in Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0048] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific embodiments. However, the following examples are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

[0049] In the following examples and comparative examples, unless otherwise specified, all reagents and consumables were purchased from conventional reagent manufacturers in the field; unless otherwise specified, the experimental methods and technical means used were conventional methods and means in the field.

[0050] Example 1

[0051] This embodiment provides a rare earth element doped ruthenium dioxide electrocatalyst, the chemical formula of the rare earth element doped ruthenium dioxide electrocatalyst with a rutile structure is Sc 0.1 Ru 0.9 O2;

[0052] The preparation method of the rare earth element-doped ruthenium dioxide electrocatalyst provided in this embodiment includes the following steps:

[0053] 0.225 mmol of RuCl3·3H2O and 0.025 mmol of ScCl3·6H2O were dissolved in 10 mL of ethanol and sonicated for 10 min. 60 mg of PVP solution dispersant was added and sonicated for 5 min to obtain a brown solution. The reaction was carried out in an 80°C oil bath under a closed environment for 6 h. The ethanol was removed by drying to obtain a black precursor powder.

[0054] The precursor powder was placed in an air atmosphere, heated to 450°C at a heating rate of 5°C / min, annealed for 300 min, and then cooled to room temperature to obtain rare earth element-doped ruthenium dioxide electrocatalyst Sc 0.1 Ru 0.9 O2.

[0055] Sc 0.1 Ru 0.9 The XRD pattern of O2 electrocatalyst is shown in Figure 1 As shown by Figure 1 It can be seen that Sc atoms completely enter the RuO2 lattice and retain the RuO2 crystal structure;

[0056] Sc 0.1 Ru 0.9 The HRTEM and EDS images of the O2 electrocatalyst are shown in Figure 2. Figure 2 and Figure 3 As shown in the figure, Sc 0.1 Ru 0.9 O2 retains the rutile structure of RuO2, and Sc, Ru and O are evenly distributed.

[0057] Example 2

[0058] This embodiment provides a rare earth element doped ruthenium dioxide electrocatalyst, the chemical formula of the rare earth element doped ruthenium dioxide electrocatalyst with a rutile structure is Y 0.15 Ru 0.85 O2;

[0059] The preparation method of the rare earth element-doped ruthenium dioxide electrocatalyst provided in this embodiment includes the following steps:

[0060] 0.2125 mmol of RuCl3·3H2O and 0.0375 mmol of YCl3·6H2O were dissolved in 10 mL of ethanol and sonicated for 10 min. 60 mg of PVP solution dispersant was added and sonicated for 5 min to obtain a brown solution. The reaction was carried out in a sealed oil bath at 75°C for 8 h, and the ethanol was removed by drying to obtain a black precursor powder.

[0061] The precursor powder was placed in an air atmosphere, heated to 400°C at a heating rate of 5°C / min, annealed for 250 min, and then cooled to room temperature to obtain rare earth element-doped ruthenium dioxide electrocatalyst Y 0.15 Ru 0.85 O2.

[0062] Y 0.15 Ru 0.85 The XRD pattern of O2 electrocatalyst is shown in Figure 4 As shown by Figure 4 It can be seen that the Y atoms completely enter the RuO2 lattice and retain the RuO2 crystal structure.

[0063] Example 3

[0064] This embodiment provides a rare earth element doped ruthenium dioxide electrocatalyst, the chemical formula of the rare earth element doped ruthenium dioxide electrocatalyst with a rutile structure is La 0.2 Ru 0.8 O2;

[0065] The preparation method of the rare earth element-doped ruthenium dioxide electrocatalyst provided in this embodiment includes the following steps:

[0066] 0.2 mmol of RuCl3·3H2O and 0.05 mmol of LaCl3·6H2O were dissolved in 10 mL of ethanol and ultrasonicated for 10 min. 60 mg of PVP solution dispersant was added and ultrasonicated for 5 min to obtain a brown solution. The reaction was carried out in an 85°C oil bath under a closed environment for 6 h. The ethanol was removed by drying to obtain a black precursor powder.

[0067] The precursor powder was placed in an air atmosphere, heated to 350°C at a heating rate of 8°C / min, annealed for 200 min, and then cooled to room temperature to obtain rare earth element-doped ruthenium dioxide electrocatalyst La 0.2 Ru 0.8 O2.

[0068] La 0.2 Ru 0.8 The XRD pattern of O2 electrocatalyst is shown in Figure 5 As shown by Figure 5 It can be seen that La atoms completely enter the RuO2 lattice and retain the RuO2 crystal structure.

[0069] Example 4

[0070] This embodiment provides a rare earth element doped ruthenium dioxide electrocatalyst, which is different from the embodiment 1 only in that the chemical formula of the rare earth element doped ruthenium dioxide electrocatalyst with rutile structure is Sc 0.05 Y 0.05 Ru 0.9O2; when preparing the rare earth element-doped ruthenium dioxide electrocatalyst, 0.025 mmol of ScCl3·6H2O was replaced with 0.0125 mmol of ScCl3·6H2O and 0.0125 mmol of YCl3·6H2O, and the other conditions remained unchanged.

[0071] Example 5

[0072] This embodiment provides a rare earth element doped ruthenium dioxide electrocatalyst, which is different from the embodiment 3 only in that the chemical formula of the rare earth element doped ruthenium dioxide electrocatalyst with rutile structure is Sc 0.1 La 0.1 Ru 0.8 O2; when preparing the rare earth element-doped ruthenium dioxide electrocatalyst, 0.05 mmol of ScCl3·6H2O was replaced with 0.025 mmol of ScCl3·6H2O and 0.025 mmol of LaCl3·6H2O, and the other conditions remained unchanged.

[0073] Example 6

[0074] This embodiment provides a rare earth element-doped ruthenium dioxide electrocatalyst, which differs from Example 1 only in that the annealing temperature is 300° C. when preparing the rare earth element-doped ruthenium dioxide electrocatalyst.

[0075] Example 7

[0076] This embodiment provides a rare earth element-doped ruthenium dioxide electrocatalyst. The difference from Example 1 is that the annealing temperature is 500° C. when preparing the rare earth element-doped ruthenium dioxide electrocatalyst.

[0077] Example 8

[0078] This embodiment provides a rare earth element-doped ruthenium dioxide electrocatalyst. The difference from Example 2 is that the annealing time is 100 minutes when preparing the rare earth element-doped ruthenium dioxide electrocatalyst.

[0079] Example 9

[0080] This embodiment provides a rare earth element-doped ruthenium dioxide electrocatalyst. The difference from Example 2 is that the annealing time is 350 minutes when preparing the rare earth element-doped ruthenium dioxide electrocatalyst.

[0081] Example 10

[0082] This embodiment provides a rare earth element-doped ruthenium dioxide electrocatalyst. The difference from Example 1 is that when preparing the rare earth element-doped ruthenium dioxide electrocatalyst, the ethanol solvent is replaced with an equal amount of water as the solvent.

[0083] Comparative Example 1

[0084] This comparative example provides a pure ruthenium dioxide electrocatalyst with the general chemical formula of RuO2. The only difference from Example 1 is that the amount of ScCl3·6H2O added during the preparation of the ruthenium dioxide electrocatalyst is 0.

[0085] HRTEM images of RuO2 electrocatalysts are shown in Figure 2. Figure 6 As shown by Figure 6 It can be seen that the prepared ruthenium dioxide electrocatalyst retains the RuO2 crystal structure.

[0086] Comparative Example 2

[0087] This comparative example provides a rare earth element-doped ruthenium dioxide electrocatalyst, which differs from Example 3 only in that, when preparing the rare earth element-doped ruthenium dioxide electrocatalyst, the molar ratio of RuCl3·3H2O and LaCl3·7H2O is 3:2, that is, 0.15 mmol of RuCl3·3H2O and 0.1 mmol of LaCl3·7H2O are weighed.

[0088] Chlorine evolution Faraday efficiency test method: The prepared rare earth element-doped ruthenium dioxide electrocatalyst was loaded on carbon paper to ensure that the catalyst loading was 1.0 mg cm -2 .

[0089] An H-type electrolytic cell uses a Nafion 117 membrane to divide the three-electrode system into a cathodic and anodic compartments. A Pt sheet electrode serves as the counter electrode and is placed in the cathodic compartment. The prepared catalyst serves as the working electrode, along with an Ag / AgCl (3.5M KCl) electrode as the reference electrode, both placed in the anodic compartment.

[0090] Chronopotentiometry (CP) was used to ensure that the electrolytic cell was at 10 mA cm -2 The chlorine production was determined by titrating the experimental results using the iodine titration method. The test results are shown in Table 1 below.

[0091] Table 1

[0092]

[0093]

[0094] The test results show that:

[0095] (1) It can be seen from Examples 1 to 5 that the rare earth element-doped ruthenium dioxide electrocatalyst provided by the present invention maintains a stable ruthenium dioxide rutile structure, has a high chlorine evolution Faraday efficiency, and the preparation method is simple and rapid, so it has good application prospects in the chlor-alkali industry.

[0096] (2) By comparing Example 1 with Example 6-Example 7, it can be seen that the present invention further controls the temperature of the precursor powder annealing treatment so that rare earth element-doped ruthenium dioxide electrocatalyst RE can be generated after heat treatment. x Ru 1- x O2, in which the rare earth elements are able to fully enter the ruthenium dioxide lattice.

[0097] (3) By comparing Example 1 with Example 8-Example 9, it can be seen that the present invention further controls the annealing time of the precursor powder so that the rare earth element-doped ruthenium dioxide electrocatalyst RE can be generated after the heat treatment. x Ru 1- x O2, in which the rare earth elements are able to fully enter the ruthenium dioxide lattice.

[0098] (4) By comparing Example 1 with Example 10, it can be seen that the present invention uses ethanol as a solvent, which can significantly improve the solubility of the raw materials compared to the traditional method of using water as a solvent, thereby improving the uniformity of the doping elements and being more conducive to increasing the doping amount to improve the catalytic activity of the catalyst.

[0099] (5) It can be seen from Example 1 and Comparative Example 1 that the rare earth element-doped ruthenium dioxide electrocatalyst provided by the present invention maintains a stable ruthenium dioxide rutile structure and has a high chlorine evolution Faraday efficiency. When no rare earth element is added, the chlorine evolution Faraday efficiency is significantly reduced.

[0100] (6) It can be seen from Example 3 and Comparative Example 2 that the present invention controls the molar ratio of hydrated ruthenium chloride and hydrated rare earth chloride to ensure that all rare earth elements in the hydrated rare earth chloride enter the ruthenium dioxide lattice, so that high-purity rare earth element-doped ruthenium dioxide electrocatalyst RE can be generated after heat treatment. x Ru 1-x O2.

[0101] In summary, the rare earth element-doped ruthenium dioxide electrocatalyst provided by the present invention maintains a stable ruthenium dioxide rutile structure, has a high chlorine evolution Faraday efficiency, and the preparation method is simple and fast, so it has good application prospects in the chlor-alkali industry.

[0102] The applicant declares that the above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the scope of protection and disclosure of the present invention.

Claims

1. A rare earth element-doped ruthenium dioxide electrocatalyst, characterized in that: The chemical formula of the rare earth element doped ruthenium dioxide electrocatalyst is RE x Ru 1-x O2; wherein RE includes any one or a combination of at least two of Sc, Y or lanthanide elements, and 0<x≤0.

5.

2. The rare earth element-doped ruthenium dioxide electrocatalyst according to claim 1, characterized in that 0＜x≤0.3。 3. A method for preparing a rare earth element-doped ruthenium dioxide electrocatalyst as claimed in claim 1 or 2, characterized in that: The preparation method comprises the following steps: A ruthenium source, a rare earth element source, a solvent and a dispersant are mixed, reacted and annealed to obtain a rare earth element-doped ruthenium dioxide electrocatalyst.

4. The preparation method according to claim 3, characterized in that The molar ratio of the metal elements contained in the ruthenium source and the rare earth element source is (9-1):

1.

5. The preparation method according to claim 3 or 4, characterized in that The ruthenium source includes ruthenium trichloride and / or a hydrate of ruthenium trichloride; Preferably, the rare earth element source includes rare earth chloride and / or rare earth chloride hydrate.

6. The preparation method according to any one of claims 3 to 5, characterized in that The solvent includes ethanol; Preferably, the dispersant comprises a PVP solution.

7. The preparation method according to any one of claims 3 to 6, characterized in that The reaction temperature is 70°C-90°C; Preferably, the reaction time is 6 h-10 h.

8. The preparation method according to any one of claims 3 to 7, characterized in that The annealing temperature is 350°C-450°C; Preferably, the heating rate of the annealing is 5°C / min-10°C / min; Preferably, the annealing time is 150 min-300 min.

9. The preparation method according to any one of claims 3 to 8, characterized in that The preparation method comprises the following steps: The ruthenium source, rare earth element source and ethanol were mixed in a molar ratio of the metal elements of (9-1):1, ultrasonicated for 10 min-30 min, PVP solution dispersant was added, and the mixture was reacted in an oil bath at 70°C-90°C for 6 h-10 h. After drying, the mixture was heated to 350°C-450°C at a heating rate of 5°C / min-10°C / min and annealed for 150 min-300 min to obtain a rare earth element-doped ruthenium dioxide electrocatalyst.

10. Use of the rare earth element-doped ruthenium dioxide electrocatalyst according to claim 1 or 2, characterized in that: The rare earth element-doped ruthenium dioxide electrocatalyst is used for chlorine evolution reaction.

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