Ternary Ru-based solid solution strong oxidizing power electrocatalyst for long-term stable electrolysis of water to produce oxygen and preparation method and application of ternary Ru-based solid solution strong oxidizing power electrocatalyst

Abstract

The invention provides a ternary Ru-based solid solution strong oxidizing power electrocatalyst for long-term stable electrolysis of water for oxygen production, and a preparation method and application of the ternary Ru-based solid solution strong oxidizing power electrocatalyst. The electrocatalyst is a RuO2 catalyst co-doped with Sn and a third metal element, and the third metal element comprises one of Ni, Co and Cu; in the electrocatalyst, the molar ratio of the Ru element to the Sn element is 1: 0.2-1: 1.5, and the molar content of the third metal element is 1-20% of the total molar content of the Ru element and the Sn element. According to the ternary Ru-based catalyst provided by the invention, through co-doping of Sn and the specific third metal, the lattice structure can be stabilized while generation of high-valence Ru is promoted, so that bidirectional improvement of activity and stability is realized.

Description

Technical Field

[0001] This invention belongs to the field of electrocatalysis technology, and relates to a ternary Ru-based solid solution strong oxidizing electrocatalyst for long-term stable water electrolysis to produce oxygen, its preparation method and application. Background Technology

[0002] Global climate change has led to frequent extreme weather events, making the reduction of greenhouse gas emissions and fossil fuel use both urgent needs and significant challenges. Electrocatalytic conversion reactions can be used for pollution and carbon reduction, offering advantages such as environmental friendliness and high controllability. Among these, the combination of water electrolysis and renewable energy has become a promising method for green hydrogen production, potentially addressing the current global energy and environmental crisis. However, in the oxygen evolution reaction (OER) occurring at the anode, mainstream alkaline water electrolysis technology faces a series of problems, including byproduct gas generation and limited current density. In contrast, proton exchange membrane electrolysis (PEMWE) technology offers significant advantages such as high current density and clean energy utilization.

[0003] IrO2, widely used in proton exchange membrane water electrolysis, is expensive and has extremely low production. In contrast, Ru costs only 13% of Ir, while its global annual production is 10 times that of Ir, making it a potential replacement for Ir-based catalysts. However, its catalytic activity is still insufficient to meet the demands of large-scale renewable energy, and its long-term stability in strongly acidic environments faces severe challenges.

[0004] Ru-based catalysts exhibit superior performance in acidic water oxidation reactions (OER), but their activity and stability have always been subject to a "seesaw problem": Ru serves as the active site for the reaction, and the generation of high-valence Ru is conducive to the adsorption and decomposition of oxidation intermediates, promoting rapid reaction. However, high-valence Ru species are easily dissolved, and at the same time, the unstable lattice structure leads to the escape of lattice oxygen, which accelerates catalyst deactivation.

[0005] Reference 1 shows that Group P elements Ga and Sn, which have unique two-electron anti-corrosion properties, can form lattice-stable solid solution oxides with Ru, thus improving stability. However, due to the lack of regulation of active sites, they are difficult to meet the requirements of efficient catalysis.

[0006] Reference 2 shows that the incorporation of Ni can effectively regulate the electronic structure of the active site Ru, thereby achieving the generation of high-valence Ru and optimizing the adsorption and decomposition of oxidation intermediates. However, the stability is still difficult to meet the needs of long-term catalysis.

[0007] It can be seen that although a series of studies have been conducted in this field on the balance between activity and stability of Ru-based catalysts, the research cannot be considered sufficient and there is still room for further exploration.

[0008] References:

[0009] Citation 1: Wu, LQ; Huang, WX; Li, DY; Jia, HN; Zhao, BB; Zhu, J.; Zhou, HQ; 10.1002 / anie.202413334.

[0010] Citation 2: Harzandi AM, Shadman S, Nissimagoudar AS, Kim DY, Lim HD,Lee JH, Kim MG, Jeong HY, Kim Y, Kim KS. Ruthenium core-shell engineering with nickel single atoms for selective oxygen evolution via nondestructivemechanism. Advanced Energy Materials. 2021 Mar;11(10):2003448. Summary of the Invention

[0011] The problem the invention aims to solve

[0012] In view of the above problems, the present invention provides a Ru-based catalyst that can improve activity while maintaining good stability.

[0013] Solution for solving the problem

[0014] The ternary Ru-based catalyst provided by this invention can stabilize the crystal structure while promoting the generation of high-valence Ru through co-doping with Sn and a specific third metal, thereby achieving a dual improvement in activity and stability.

[0015] The present invention first provides a ternary Ru-based solid solution strong oxidizing electrocatalyst for long-term stable water electrolysis to produce oxygen, wherein the electrocatalyst is a RuO2 catalyst co-doped with Sn and a third metal element, wherein the third metal element includes one of Ni, Co, and Cu;

[0016] In the electrocatalyst, the molar ratio of Ru to Sn is 1:0.2 to 1:1.5, and the molar content of the third metal element is 1 to 20% of the total molar content of Ru and Sn.

[0017] According to the electrocatalyst of the present invention, the molar ratio of Ru to Sn is 1:0.9 to 1:1.1; and / or,

[0018] The molar content of the third metal element is 10-15% of the total molar content of Ru and Sn elements.

[0019] The present invention also provides a method for preparing a ternary Ru-based solid solution strong oxidizing electrocatalyst according to the present invention, which includes the following steps:

[0020] S1: Dissolve the Ru precursor salt, Sn precursor salt and third metal precursor salt in an organic solvent to obtain a mixed solution;

[0021] S2: The mixture is heated, dried, and ground to obtain powder;

[0022] S3: Anneal the powder in air and cool it to obtain a ternary Ru-based electrocatalyst.

[0023] According to the preparation method of the present invention, in step S1,

[0024] The Ru precursor salt includes one or more of anhydrous ruthenium chloride and its hydrate, ruthenium acetate, and hexaammineruthenium chloride; and / or,

[0025] The Sn precursor salt includes one or more of anhydrous tin tetrachloride and its hydrate, and stannous sulfate; and / or,

[0026] The third metal precursor salt includes one or more of anhydrous nickel chloride and its hydrate, nickel acetate, nickel sulfate, anhydrous cobalt chloride and its hydrate, and anhydrous copper chloride and its hydrate; and / or,

[0027] The organic solvent includes ethanol; and / or,

[0028] The molar concentration of Ru in the mixture is 0.01~2 mol / L.

[0029] According to the preparation method of the present invention, in step S2, the heating temperature is 70~90℃ and the heating time is 4~6h.

[0030] According to the preparation method of the present invention, in step S3, the annealing step has a heating rate of 5~10℃ / min, an annealing temperature of 200~400℃, and an annealing time of 2~3h.

[0031] The present invention also provides a method for electrocatalytic water decomposition to produce oxygen, which includes the following steps:

[0032] (1) Mix the second organic solvent, ultrapure water, Nafion solution and the electrocatalyst according to the present invention to obtain a dispersion, and coat the dispersion on the surface of carbon paper or carbon cloth, and dry it to obtain a working electrode;

[0033] (2) The working electrode, the counter electrode and the reference electrode are combined to form a three-electrode system, which is then inserted into the electrolyte solution to form an electrolytic cell, and water is decomposed to produce oxygen through electrocatalysis.

[0034] According to the method of the present invention, the density of the electrocatalyst supported on the working electrode is 0.5~0.75 mg / cm³. 2 .

[0035] According to the method of the present invention, the second organic solvent comprises isopropanol or ethanol; and / or,

[0036] The resistivity of the ultrapure water is 18.2 MΩ. cm; and / or,

[0037] The potential of the working electrode is 0~1.7V vs. RHE; and / or,

[0038] The reference electrode is an Ag / AgCl electrode, the counter electrode is a platinum mesh electrode, and the electrolyte solution is an H2SO4 solution.

[0039] According to the method of the present invention, the concentration of the H2SO4 solution is 0.5~1.5 mol / L.

[0040] The effects of the invention

[0041] 1. The method for preparing a ternary Ru-based solid solution electrocatalyst with strong oxidizing power provided by the present invention significantly enhances the oxidizing power of RuO2 by co-doping with Sn and a specific third metal, activates the generation of high-valence Ru sites, optimizes the adsorption and decomposition of oxidation intermediates, thereby promoting proton transfer, and forming a stable ternary solid solution oxide structure, thus achieving a balanced improvement in the activity and stability of Ru-based catalysts.

[0042] 2. The method for producing oxygen by electrocatalytic water splitting provided by the present invention effectively improves the electrocatalytic performance and stability by loading a ternary Ru-based solid solution electrocatalyst on the working electrode, thereby achieving long-term stable oxygen production. Attached Figure Description

[0043] Figure 1 The XRD test results of the catalysts prepared in Example 1 and Comparative Examples 1-4 are shown.

[0044] Figure 2 The XRD test results of the catalysts prepared in Examples 1-4 and Comparative Examples 3-4 are shown.

[0045] Figure 3 The Ru 3d XPS spectra of the catalysts prepared in Example 1 and Comparative Examples 1-3 are shown.

[0046] Figure 4 The LSV curve test results of water electrolysis for oxygen production using the catalysts prepared in Examples 1 and Comparative Examples 1-3 and CM RuO2 working electrodes are shown.

[0047] Figure 5 The LSV curve test results of water electrolysis for oxygen production using the catalysts prepared in Examples 1-4 and Comparative Example 3 and the working electrode of CM RuO2 are shown.

[0048] Figure 6 The LSV curve test results of water electrolysis for oxygen production using the catalysts prepared in Examples 1, 5-7 and Comparative Example 3 and CM RuO2 working electrode are shown.

[0049] Figure 7 The LSV curve test results of water electrolysis for oxygen production using the catalysts prepared in Examples 1, 8-9 and Comparative Examples 3, 5-8 and the working electrode of CM RuO2 are shown.

[0050] Figure 8 The stability test results of water electrolysis for oxygen production using a working electrode containing the catalyst prepared in Example 1 are shown in the figure.

[0051] Figure 9 The stability test results of water electrolysis for oxygen production using the catalysts prepared in Comparative Examples 1-3 and CM RuO2 working electrodes are shown. Detailed Implementation

[0052] Various exemplary embodiments, features, and aspects of the present invention will be described in detail below. The term "exemplary" as used herein means "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as superior to or better than other embodiments.

[0053] Furthermore, to better illustrate the present invention, numerous specific details are set forth in the following detailed embodiments. Those skilled in the art should understand that the present invention can be practiced without certain specific details. In other instances, methods, means, apparatus, and steps well known to those skilled in the art have not been described in detail in order to highlight the spirit of the present invention.

[0054] Unless otherwise stated, all units used in this specification are international standard units, and all numerical values ​​and ranges appearing in this invention should be understood to include systematic errors that are unavoidable in industrial production.

[0055] In this specification, the word "may" has two meanings: to perform a certain process and not to perform a certain process.

[0056] In this specification, references to "some specific / preferred embodiments," "other specific / preferred embodiments," "implementation," etc., refer to specific elements (e.g., features, structures, properties, and / or characteristics) related to that embodiment, which are included in at least one of the embodiments described herein and may or may not be present in other embodiments. Furthermore, it should be understood that these elements may be combined in any suitable manner in various embodiments.

[0057] In this specification, the range of values ​​referred to as "value A to value B" refers to the range including the endpoint values ​​A and B.

[0058] [First aspect]

[0059] The first aspect of the present invention provides a ternary Ru-based solid solution strong oxidizing electrocatalyst for long-term stable water electrolysis to produce oxygen. The electrocatalyst is a RuO2 catalyst co-doped with Sn and a third metal element, wherein Sn and the third metal element are co-doped into the RuO2 lattice to form a rutile solid solution oxide structure.

[0060] In this invention, the third metal includes one of Ni, Co, and Cu, with Ni being preferred. Co-doping with a specific third metal and Sn can simultaneously promote the generation of high-valence Ru and stabilize the crystal structure, thereby achieving a dual improvement in both activity and stability.

[0061] In this invention, the general formula of the electrocatalyst can be expressed as Sn-M-RuO2, where M represents a third metal element. It should be noted that although the oxygen atom content in the catalyst actually increases slightly due to the promotion of the production of high-valence Ru after Sn and the third metal element are doped, it still satisfies the rutile crystal form as a whole. Therefore, the number of oxygen atoms in Sn-M-RuO2 is still approximately written as 2.

[0062] In this invention, the molar ratio of Ru to Sn is 1:0.2 to 1:1.5, preferably 1:0.9 to 1:1.1, such as 1:0.3, 1:0.5, 1:0.7, 1:0.9, 1:1, 1:1.3, etc.; the molar content of the third metal element is 1 to 20% of the total molar content of Ru and Sn, preferably 10 to 15%, such as 2%, 5%, 8%, 10%, 12%, 15%, 18%, etc. When the ratio of Ru, Sn and the third metal element is within the above range, a stable solid solution oxide structure can be formed. When the proportion of Ni is less than 1%, it is difficult to achieve the above effect. When the amount of Ni exceeds 20%, the crystal lattice is difficult to stabilize, and the above effect cannot be further improved effectively.

[0063] [Second aspect]

[0064] A second aspect of the present invention provides a method for preparing a ternary Ru-based solid solution strong oxidizing electrocatalyst according to the first aspect, comprising the following steps:

[0065] S1: Dissolve the Ru precursor salt, Sn precursor salt and third metal precursor salt in an organic solvent to obtain a mixed solution;

[0066] S2: The mixture is heated, dried, and ground to obtain powder;

[0067] S3: Anneal the powder in air and cool it to obtain a ternary Ru-based electrocatalyst.

[0068] (Step S1)

[0069] Step S1 of the present invention is a mixing step, specifically, dissolving the Ru precursor salt, Sn precursor salt and third metal precursor salt in an organic solvent to obtain a mixed solution.

[0070] The amounts of the Ru precursor salt, Sn precursor salt, and third metal precursor salt need only satisfy the element ratios described in the first aspect.

[0071] In some specific embodiments, the Ru precursor salt may include one or more of anhydrous ruthenium chloride and its hydrate, ruthenium acetate, hexaammineruthenium chloride, etc., wherein the ruthenium chloride hydrate may include ruthenium chloride trihydrate, etc.; the Sn precursor salt may include one or more of anhydrous tin tetrachloride and its hydrate, stannous sulfate, etc., wherein the tin tetrachloride hydrate may include tin tetrachloride dihydrate, tin tetrachloride trihydrate, tin tetrachloride tetrahydrate, and tin tetrachloride pentahydrate, etc.; the third metal precursor salt may include one or more of anhydrous nickel chloride and its hydrate, nickel acetate, nickel sulfate, anhydrous cobalt chloride and its hydrate, anhydrous copper chloride and its hydrate, wherein the nickel chloride hydrate may include nickel chloride tetrahydrate, nickel chloride hexahydrate, etc.

[0072] In some specific implementations, the organic solvent may include ethanol, etc.

[0073] In some specific implementations, the molar concentration of Ru in the mixture can be 0.01~2 mol / L, for example, 0.05 mol / L, 0.1 mol / L, 0.5 mol / L, 1 mol / L, 1.5 mol / L, etc.

[0074] In some specific implementations, to make the dissolution more complete, ultrasonic dissolution can be used, and the ultrasonic dissolution time can be 30-60 minutes.

[0075] (Step S2)

[0076] Step S2 of the present invention is a heat treatment step, specifically, the mixture is heated, dried and ground to obtain powder.

[0077] In some specific implementations, the heating can be a common heating method such as water bath heating. The heating temperature can be 70~90℃, for example, 75℃, 80℃, 85℃, etc., and the heating time can be 4~6h, for example, 4.5h, 5h, 5.5h, etc., and the water bath heating is stopped after a clearly reflective black solid is observed.

[0078] In some specific implementations, the drying temperature can be 80℃~100℃, for example, 85℃, 90℃, or 95℃, and the drying time can be more than 12 hours.

[0079] (Step S3)

[0080] Step S3 of this invention is an annealing step, specifically, annealing the powder in air and cooling it to obtain a ternary Ru-based electrocatalyst. Through the annealing step, Sn and a third metal can be co-doped into a stable ruthenium oxide lattice.

[0081] In some specific implementations, the heating rate in the annealing step can be 5~10℃ / min, for example, 6℃ / min, 7℃ / min, 8℃ / min, 9℃ / min, etc.; the annealing temperature can be 200~400℃, for example, 250℃, 300℃, 350℃, etc.; and the annealing time can be 2~3h, for example, 2.2h, 2.5h, 2.8h, etc. Under the above annealing conditions, the co-doping of Sn and a third metal into the ruthenium oxide lattice can be effectively achieved. When the annealing temperature is below 200℃, it is difficult to achieve the above effect; when the annealing temperature is above 400℃, excessive bonding will lead to a decrease in catalytic performance.

[0082] [Third aspect]

[0083] A third aspect of the present invention provides a method for electrocatalytic water decomposition to produce oxygen, characterized by comprising the following steps:

[0084] (1) Mix the second organic solvent, ultrapure water, Nafion solution and the electrocatalyst according to the first aspect to obtain a dispersion, and coat the dispersion on the surface of carbon paper or carbon cloth, and dry it to obtain a working electrode;

[0085] (2) The working electrode, the counter electrode and the reference electrode are combined to form a three-electrode system, which is then inserted into the electrolyte solution to form an electrolytic cell, and water is decomposed to produce oxygen through electrocatalysis.

[0086] In some specific embodiments, the second organic solvent may be isopropanol or ethanol, with isopropanol being preferred.

[0087] In some specific implementations, the mixing step may use ultrasonic treatment, which may last for 0.5 to 1 hour.

[0088] In some specific implementations, the resistivity of the ultrapure water is 18.2 MΩ. cm.

[0089] In some specific implementations, the ratio of the second organic solvent, ultrapure water, Nafion (perfluorosulfonic acid polymer) solution and electrocatalyst can be (960~980) μL:(10~30) μL:(5~15) μL:(3~8) mg, preferably, the ratio can be 970 μL:20 μL:10 μL:2.5 mg.

[0090] In some specific embodiments, when the dispersion is coated onto the surface of carbon paper or carbon cloth, per 1 cm 2 The amount of dispersion applied is approximately 50 μl, and after drying, it is applied again, repeating this process 4 to 6 times. The drying process is not particularly limited and can be selected as needed.

[0091] In some specific embodiments, the density of the electrocatalyst supported on the working electrode is 0.5~0.75 mg / cm³. 2 For example, it can be 0.55 mg / cm³ 2 0.6 mg / cm 2 0.65 mg / cm 2 0.7 mg / cm 2 wait.

[0092] The present invention does not particularly limit the type of counter electrode, and commonly used counter electrodes in the art, such as platinum (Pt) mesh electrodes, can be used.

[0093] The present invention does not particularly limit the type of reference electrode, and commonly used reference electrodes in the art can be used, such as Ag / AgCl reference electrode (RHE).

[0094] In some specific implementations, the potential of the working electrode is 0~1.7 V vs. RHE, for example, it can be 0.2 V vs. RHE, 0.5 V vs. RHE, 0.8 V vs. RHE, 1 V vs. RHE, 1.2 V vs. RHE, 1.4 V vs. RHE, 1.6 V vs. RHE, etc.

[0095] The present invention does not particularly limit the type of electrolyte solution used, and commonly used electrolyte solutions in the art, such as H2SO4 solution, can be used. Preferably, the concentration of the H2SO4 solution is 0.5~1.5 mol / L.

[0096] Example

[0097] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0098] I. Catalyst Preparation

[0099] Example 1

[0100] Sn 45% -Ni 10% -Ru 45% The preparation method of O2 catalyst is as follows:

[0101] (1) Ruthenium chloride trihydrate (RuCl3·3H2O) was selected as the Ru precursor salt, tin chloride pentahydrate (SnCl4·5H2O) as the Sn precursor salt, and nickel chloride hexahydrate (NiCl2·6H2O) as the third metal precursor salt. Weigh 0.235 g (0.90 mmol) of RuCl3·3H2O, 0.315 g (0.9 mmol) of SnCl4·5H2O and 0.047 g (0.2 mmol) of NiCl2·6H2O, dissolve them in 10 mL of ethanol, stir for 10 min to prepare a mixed solution, and sonicate the mixed solution for 30 min.

[0102] (2) After heating in a water bath at 70℃ for 5 hours, a distinctly reflective black solid was observed, and heating was stopped.

[0103] (3) Place the reflective black solid obtained in step (2) in a vacuum drying oven and dry it overnight at 90°C for more than 12 hours;

[0104] (4) Grind the reflective black solid and anneal it at 300°C for 2 hours in air at a heating rate of 10°C / min to prepare Sn. 45% -Ni 10% -Ru 45% O2, in which the amount of Ni doping is approximately 10% of the total molar amount of Sn and Ru.

[0105] Example 2

[0106] Sn 47.5% -Ni 5% -Ru 47.5% Preparation method of O2 catalyst:

[0107] The only difference from Example 1 is that the amount of Ni doping is replaced with 5%, that is, the amount of NiCl2·6H2O added is replaced with 0.024g (0.09mmol), and the other steps are the same as in Example 1.

[0108] Example 3

[0109] Sn 42.5% -Ni 15% -Ru 42.5% Preparation method of O2 catalyst:

[0110] The only difference from Example 1 is that the amount of Ni doping is replaced with 15%, that is, the amount of NiCl2·6H2O added is replaced with 0.071g (0.27mmol), and the other steps are the same as in Example 1.

[0111] Example 4

[0112] Sn 40% -Ni 20% -Ru 40% Preparation method of O2 catalyst:

[0113] The only difference from Example 1 is that the amount of Ni doping is replaced with 20%, that is, the amount of NiCl2·6H2O added is replaced with 0.095g (0.36mmol), and the other steps are the same as in Example 1.

[0114] Example 5

[0115] Sn 9% -Ni 10% -Ru 81% Preparation method of O2 catalyst:

[0116] The difference from Example 1 is that RuCl3·3H2O is replaced with anhydrous RuCl3, the amount of RuCl3 added is 0.336g (1.62mmol), and the amount of SnCl4·5H2O added is replaced with 0.063g (0.18mmol). The other steps are the same as in Example 1.

[0117] Example 6

[0118] Sn 22.5% -Ni 10% -Ru 67.5% Preparation method of O2 catalyst:

[0119] The difference from Example 1 is that RuCl3·3H2O is replaced with anhydrous RuCl3, the amount of RuCl3 added is 0.28g (1.35mmol), and the amount of SnCl4·5H2O added is replaced with 0.158g (0.45mmol). The other steps are the same as in Example 1.

[0120] Example 7

[0121] Sn 67.5% -Ni 10% -Ru 22.5% Preparation method of O2 catalyst:

[0122] The difference from Example 1 is that RuCl3·3H2O is replaced with anhydrous RuCl3, the amount of RuCl3 added is 0.093g (0.45mmol), and the amount of SnCl4·5H2O added is replaced with 0.473g (1.45mmol). The other steps are the same as in Example 1.

[0123] Example 8

[0124] Sn 45% -Co 10% -Ru 45% Preparation method of O2 catalyst:

[0125] The only difference from Example 1 is that NiCl2·6H2O is replaced with CoCl2 as the third metal precursor salt, and the amount of CoCl2 added is 0.026g (0.2mmol). The other steps are the same as in Example 1.

[0126] Example 9

[0127] Sn 45% -Cu 10% -Ru 45% Preparation method of O2 catalyst:

[0128] The only difference from Example 1 is that NiCl2·6H2O is replaced with CuCl2 as the third metal precursor salt, and the amount of CuCl2 added is 0.027g (0.2mmol). The other steps are the same as in Example 1.

[0129] Comparative Example 1

[0130] Sn 50% -Ru 50% Preparation method of O2 catalyst:

[0131] The difference from Example 1 is that no third metal precursor salt is added, but the other steps are the same as in Example 1.

[0132] Comparative Example 2

[0133] Ni 50% -Ru 50% Preparation method of O2 catalyst:

[0134] The difference from Example 1 is that Sn precursor salt is not added, the amount of RuCl3·3H2O added is 0.261g (1mmol), and the amount of NiCl2·6H2O added is 0.238g (1mmol). The other steps are the same as in Example 1.

[0135] Comparative Example 3

[0136] Preparation method of RuO2 catalyst:

[0137] The difference from Example 1 is that Sn precursor salt and third metal precursor salt are not added, while the other steps are the same as in Example 1.

[0138] Comparative Example 4

[0139] Preparation method of SnO2 catalyst:

[0140] The difference from Example 1 is that Ru precursor salt and third metal precursor salt are not added, while the other steps are the same as in Example 1.

[0141] Comparative Example 5

[0142] Sn 45% -K 10% -Ru 45% Preparation method of O2 catalyst:

[0143] The only difference from Example 1 is that NiCl2·6H2O is replaced with KCl as the third metal precursor salt, and the amount of KCl added is 0.015g (0.2mmol). The other steps are the same as in Example 1.

[0144] Comparative Example 6

[0145] Sn45% -Mn 10% -Ru 45% Preparation method of O2 catalyst:

[0146] The only difference from Example 1 is that NiCl2·6H2O is replaced with MnCl2·4H2O as the third metal precursor salt, and the amount of MnCl2·4H2O added is 0.039g (0.2mmol). The other steps are the same as in Example 1.

[0147] Comparative Example 7

[0148] Sn 45% -Zn 10% -Ru 45% Preparation method of O2 catalyst:

[0149] The only difference from Example 1 is that NiCl2·6H2O is replaced with ZnCl2 as the third metal precursor salt, and the amount of ZnCl2 added is 0.027g (0.2mmol). The other steps are the same as in Example 1.

[0150] Comparative Example 8

[0151] Sn 45% -Fe 10% -Ru 45% Preparation method of O2 catalyst:

[0152] The only difference from Example 1 is that NiCl2·6H2O is replaced with FeCl2·4H2O as the third metal precursor salt, and the amount of FeCl2·4H2O added is 0.039g (0.2mmol). The other steps are the same as in Example 1.

[0153] Performance testing

[0154] 1. XRD test: XRD tests were performed on the catalysts obtained in Examples 1-4 and Comparative Examples 1-4. The test results are as follows: Figure 1 and Figure 2 As shown.

[0155] Depend on Figure 1 It can be seen that the Sn obtained by doping RuO2 (Comparative Example 3) with Sn 50% -Ru 50% The O2 catalyst (Comparative Example 1) formed a stable solid solution structure, while the Ni doping in RuO2 (Comparative Example 3) resulted in Ni... 50% -Ru 50% The O2 catalyst (Comparative Example 2) exhibits a certain degree of amorphous crystal structure. However, the Sn catalyst obtained after co-doping with Ni and Sn... 45% -Ni 10% -Ru45% The O2 catalyst (Example 1) formed a stable solid solution structure.

[0156] Depend on Figure 2 It can be seen that ternary Ru-based catalysts with different Ni doping ratios all formed stable solid solution structures.

[0157] 2. XPS Test: The catalysts obtained in Example 1 and Comparative Examples 1-3 were subjected to XPS tests, and the test results are as follows: Figure 3 As shown.

[0158] Depend on Figure 3 The XPS spectrum of Ru 3d in Comparative Example 3 (RuO2) shows that the Ru 3d... 5 / 2 The peak is located at 280.6 eV, while the comparative example 1 with Sn doping (Sn) 50% -Ru 50% O2) of Ru 3d 5 / 2 The peak shifted to a lower binding energy by 0.2 eV. Comparative Example 2 after Ni doping (Ni 50% -Ru 50% O2) of Ru 3d 5 / 2 The peak shifted to a higher binding energy by 0.35 eV. This indicates that Sn doping led to Ru forming a lower valence state, while Ni doping resulted in an increase in the valence state of Ru. Meanwhile, in Example 1 (Sn... 45% -Ni 10% -Ru 45% O2) of Ru 3d 5 / 2 The peak is located at 281.25 eV, showing a shift to a higher binding energy of 0.65 eV compared to Comparative Example 3 (RuO2), and also compared to Comparative Example 2 (Ni). 50% -Ru 50% O2) of Ru 3d 5 / 2 The peak shifted to a higher binding energy by 0.3 eV, confirming the significant increase in the Ru valence state after Sn and Ni co-doping. The Ru valence state is further increased compared to when Ni is doped alone. This demonstrates that the co-doping of Sn and Ni can significantly enhance the oxidizing power of RuO2, activate the generation of high-valence Ru sites, optimize the adsorption and decomposition of oxidation intermediates, thereby promoting proton transfer and forming a stable ternary solid solution oxide structure.

[0159] II. Electrocatalytic decomposition of water to produce oxygen

[0160] Example 10

[0161] The method of producing oxygen by electrocatalytic decomposition of water using a catalyst is as follows:

[0162] (1) Weigh 2.5 mg of the catalysts obtained in Examples 1-9 and Comparative Examples 1-3 and 5-8 and commercial RuO2 (CMRuO2), respectively, and prepare Ink solutions with 970 μL of isopropanol, 20 μL of ultrapure water and 10 μL of Nafion solution.

[0163] (2) Sonicate the Ink solution for 30 min to disperse it evenly. Coat it onto carbon cloth with a coating area of ​​1×1 cm. Apply 50 μl each time. After each application, place it in air dry at 80°C for about 30 min. Repeat this process 4 times to obtain the working electrode.

[0164] (3) The working electrode, Pt mesh (counter electrode), and Ag / AgCl (reference electrode) are combined to form a three-electrode system, which is then inserted into a 0.5M H2SO4 solution to form an electrolytic cell. The acidic electrolysis of water to produce oxygen is carried out in the electrolytic cell.

[0165] Performance testing

[0166] 1. Electrolysis of water oxygen production performance test: Under the working voltage of 1.35~1.5V vs. RHE, O2 gas was passed into the electrolyte solution at a flow rate of 10mL / min for 30min to form a saturated oxygen environment. LSV curve testing was then performed, and the results are as follows: Figures 4-7 As shown.

[0167] Depend on Figure 4 It can be seen that using Sn containing Example 1 45% -Ni 10% -Ru 45% The working electrode of the O2 catalyst reaches 10 mA·cm⁻¹ during the electrocatalytic electrolysis of water to produce oxygen. -2 Only 198mV is required, while using Sn containing Comparative Example 1 50% -Ru 50% The O2 catalyst requires 250 mV and uses Ni containing Comparative Example 2. 50% -Ru 50% The required voltage for the O2 catalyst is 290 mV, while the required voltage for the RuO2 catalyst containing Comparative Example 3 is 330 mV, and the required voltage for the RuO2 catalyst containing CM is 320 mV. This demonstrates that the Sn-Ni-RuO2 catalyst can significantly improve oxygen production performance.

[0168] Depend on Figure 5 It can be seen that using Sn containing Example 2 47.5% -Ni 5% -Ru 47.5% The working electrode of the O2 catalyst reaches 10 mA·cm⁻¹ during the electrocatalytic electrolysis of water to produce oxygen. -2 221mV is required, using Sn from Example 3. 42.5% -Ni 15% -Ru42.5% The O2 catalyst requires 207 mV, using Sn from Example 4. 40% -Ni 20% -Ru 40% The O2 catalyst requires 217 mV.

[0169] Depend on Figure 6 It can be seen that using Sn containing the ingredients of Example 5 9% -Ni 10% -Ru 81% The working electrode of the O2 catalyst reaches 10 mA·cm⁻¹ during the electrocatalytic electrolysis of water to produce oxygen. -2 218mV required, using Sn from Example 6 22.5% -Ni 10% -Ru 67.5% The O2 catalyst requires 225 mV, using Sn from Example 7. 67.5% -Ni 10% -Ru 22.5% The O2 catalyst requires 220mV.

[0170] Depend on Figure 7 It can be seen that using Sn containing Example 8 45% -Co 10% -Ru 45% The working electrode of the O2 catalyst reaches 10 mA·cm⁻¹ during the electrocatalytic electrolysis of water to produce oxygen. -2 222mV required, using Sn from Example 9 45% -Cu 10% -Ru 45% The O2 catalyst requires 226 mV, using Sn containing comparative example 5. 45% -K 10% -Ru 45% The O2 catalyst requires 238 mV, using Sn containing comparative example 6. 45% -Mn 10% -Ru 45% The O2 catalyst requires 240 mV, using Sn containing Comparative Example 7. 45% -Zn 10% -Ru 45% The O2 catalyst requires 286 mV, using Sn containing comparative example 8. 45% -Fe 10% -Ru 45% The O2 catalyst requires 236mV.

[0171] It can be seen that the catalysts prepared in Examples 1-8 can significantly improve oxygen production performance.

[0172] 2. Stability test of oxygen production by water electrolysis: O2 gas was introduced into the electrolyte solution at a flow rate of 10 mL / min, followed by a test at 10 mA·cm⁻¹. -2 Stability tests were conducted under constant current, and the results are as follows: Figures 8-9 As shown.

[0173] Depend on Figure 8 It can be seen that at 10mA·cm -2 At a current density, Sn containing the sample from Example 1 was used. 45% -Ni 10% -Ru 45% The initial oxygen production of the working electrode of the O2 catalyst through electrocatalytic water electrolysis still exhibited stable oxygen production performance under strong acid conditions after 150 hours of constant current reaction.

[0174] And by Figure 9 It can be seen that the working electrode using the RuO2 catalyst from Comparative Example 3 becomes ineffective after 1 hour of reaction, while the working electrode using the CM RuO2 catalyst becomes ineffective after approximately 6 hours of reaction. The working electrode using the Sn catalyst from Comparative Example 1 also becomes ineffective. 50% -Ru 50% The working electrode of the O2 catalyst became ineffective after about 20 hours of reaction. Ni containing Comparative Example 2 was then used. 50% -Ru 50% The working electrode of the O2 catalyst became ineffective after approximately 8 hours of reaction. This indicates that Sn... 45% -Ni 10% -Ru 45% O2 catalysts can significantly improve the stability of oxygen production under strong acid conditions.

[0175] It should be noted that although the technical solution of the present invention has been described with specific examples, those skilled in the art will understand that the present invention should not be limited thereto.

[0176] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A ternary Ru-based solid solution high-oxidizing-power electrocatalyst for long-term stable oxygen production through water electrolysis, characterized in that, The electrocatalyst is a RuO2 catalyst co-doped with Sn and a third metal element, wherein the third metal element includes one of Ni, Co, and Cu; In the electrocatalyst, the molar ratio of Ru to Sn is 1:0.2 to 1:1.5, and the molar content of the third metal element is 1 to 20% of the total molar content of Ru and Sn.

2. The electrocatalyst according to claim 1, characterized in that, The molar ratio of Ru to Sn is 1:0.9 to 1:1.1; and / or, The molar content of the third metal element is 10-15% of the total molar content of Ru and Sn elements.

3. A method for preparing a ternary Ru-based solid solution strong oxidizing electrocatalyst according to claim 1 or 2, characterized in that, Includes the following steps: S1: Dissolve the Ru precursor salt, Sn precursor salt and third metal precursor salt in an organic solvent to obtain a mixed solution; S2: The mixture is heated, dried, and ground to obtain powder; S3: Anneal the powder in air and cool it to obtain a ternary Ru-based electrocatalyst.

4. The preparation method according to claim 3, characterized in that, In step S1, The Ru precursor salt includes one or more of anhydrous ruthenium chloride and its hydrate, ruthenium acetate, and hexaammineruthenium chloride; and / or, The Sn precursor salt includes one or more of anhydrous tin tetrachloride and its hydrate, and stannous sulfate; and / or, The third metal precursor salt includes one or more of anhydrous nickel chloride and its hydrate, nickel acetate, nickel sulfate, anhydrous cobalt chloride and its hydrate, and anhydrous copper chloride and its hydrate; and / or, The organic solvent includes ethanol; and / or, The molar concentration of Ru in the mixture is 0.01~2 mol / L.

5. The preparation method according to claim 3 or 4, characterized in that, In step S2, the heating temperature is 70~90℃, and the heating time is 4~6h.

6. The preparation method according to claim 3 or 4, characterized in that, In step S3, during the annealing process, the heating rate is 5~10℃ / min, the annealing temperature is 200~400℃, and the annealing time is 2~3h.

7. A method for electrocatalytic water decomposition to produce oxygen, characterized in that, Includes the following steps: (1) Mix the second organic solvent, ultrapure water, Nafion solution and the electrocatalyst according to claim 1 or 2 to obtain a dispersion, and coat the dispersion on the surface of carbon paper or carbon cloth, and dry it to obtain a working electrode; (2) The working electrode, the counter electrode and the reference electrode are combined to form a three-electrode system, which is then inserted into the electrolyte solution to form an electrolytic cell, and water is decomposed to produce oxygen through electrocatalysis.

8. The method according to claim 7, characterized in that, The density of the electrocatalyst supported on the working electrode is 0.5~0.75 mg / cm³. 2 .

9. The method according to claim 7 or 8, characterized in that, The second organic solvent includes isopropanol or ethanol; and / or, The resistivity of the ultrapure water is 18.2 MΩ. cm; and / or, The potential of the working electrode is 0~1.7V vs. RHE; and / or, The reference electrode is an Ag / AgCl electrode, the counter electrode is a platinum mesh electrode, and the electrolyte solution is an H2SO4 solution.

10. The method according to claim 9, characterized in that, The concentration of the H2SO4 solution is 0.5~1.5 mol / L.

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