A low-Ru basic HER electrocatalyst, its preparation method and application

Abstract

This application relates to the field of electrocatalyst technology, disclosing a low-Ru basic HER electrocatalyst, its preparation method, and its application. The low-Ru basic HER electrocatalyst comprises an M-N-C substrate formed by metal M anchored at a single site on nitrogen-doped carbon, and Ru uniformly distributed on the M-N-C substrate; wherein the metal M includes at least one of Ga, In, Sn, or Sb. In this application's low-Ru basic HER electrocatalyst, metal M is anchored at a single site on nitrogen-doped carbon (N-C) to form M-N-C, while Ru is uniformly distributed in clusters of approximately 2 nm on the M-N-C support. Strong catalyst-support interactions occur between the Ru clusters and M-N-C due to Ru-M interactions; simultaneously, the Ru-H adsorption energy is optimized, and the oxygen-loving M further enhances water dissociation capacity, thereby improving the basic HER performance. The electrocatalyst of this application has a low Ru content, with a Ru loading of only 0.08 mg cm⁻¹ at the cathode of an anion exchange membrane electrolyzer. ‑2 Around [a certain amount], while ensuring catalytic activity, the cost was significantly reduced.

Description

Technical Field

[0001] This application relates to the field of electrocatalyst technology, specifically to a low-Ru basic HER electrocatalyst, its preparation method, and its application. Background Technology

[0002] Hydrogen energy, as an ideal clean energy carrier, can effectively store renewable and intermittent energy sources and efficiently convert them into electricity through fuel cells, making it a highly promising green energy solution. Water electrolysis provides an efficient and environmentally friendly method for large-scale production of high-purity hydrogen. Traditional alkaline water electrolysis technology does not rely on precious metals, but its operating current density is relatively low, only 0.3-0.4 A cm⁻¹. -2 This limits its efficiency; in contrast, proton exchange membrane electrolysis can achieve efficiency up to 1 A cm⁻¹. -2 It operates at high current densities, but its dependence on the noble metals Ir and Pt limits its large-scale application.

[0003] Anion exchange membrane electrolysis is a technology that utilizes water that can selectively conduct anions (such as hydroxide ions, OH- ions). - This paper describes a membrane-based electrolytic water splitting technology for efficient hydrogen production. In the cathodic hydrogen evolution reaction (HER) of this system, while commercially available Pt / C catalysts exhibit excellent catalytic activity in acidic media, their reaction kinetics are approximately an order of magnitude slower under alkaline conditions due to limited water molecule dissociation. Furthermore, the weak interaction between Pt metal and the carbon support makes it prone to metal particle aggregation or detachment during the reaction, significantly reducing catalyst stability.

[0004] To address the aforementioned issues, this invention proposes to replace Pt with Ru metal, which has significantly superior water-splitting capabilities, as a highly efficient electrocatalyst for the alkaline hydrogen evolution reaction. Simultaneously, by rationally constructing single-atom sites on a carbon support, the electronic coupling and structural stability between Ru and the support can be enhanced while optimizing the Ru-H adsorption energy, thus balancing catalytic activity and durability. This provides a new research approach and design strategy for achieving efficient and stable alkaline water electrolysis. Summary of the Invention

[0005] This application provides a low-Ru basic HER electrocatalyst, its preparation method, and its application, aiming to solve the technical problems of low catalytic activity and low stability of existing Ru catalysts.

[0006] To achieve the above objectives, the present application adopts the following technical solution.

[0007] A first aspect of this application provides a low-Ru alkaline HER electrocatalyst, comprising: a metal M anchored at a single site on a nitrogen-doped carbon MNC substrate, and Ru uniformly distributed on the MNC substrate; The metal M includes at least one of Ga, In, Sn, or Sb.

[0008] Preferably, the low-Ru alkaline HER electrocatalyst contains 2-15 wt% Ru and 1-5 wt% M.

[0009] Preferably, the Ru is uniformly distributed on the MNC substrate in the form of clusters.

[0010] A second aspect of this application provides a method for preparing the aforementioned low-Ru basic HER electrocatalyst, comprising: S1, dissolve the metal salt of M and the zinc salt in methanol to obtain solution A; dissolve dimethylimidazolium in methanol to obtain solution B; mix solution A and solution B and react them, then dry the reaction product to obtain the precursor; S2, the precursor is calcined to obtain the MNC substrate; S3, the MNC substrate is uniformly dispersed in ethanol, then an ethanol solution of Ru salt is added, mixed evenly and evaporated to obtain the Ru-loaded MNC substrate. S4. The MNC substrate loaded with Ru salt is calcined to obtain the Ru / MNC catalyst, namely the low-Ru basic HER electrocatalyst.

[0011] Preferably, the M metal salt includes at least one of gallium acetylacetonate, indium acetylacetonate, tin acetylacetonate, or antimony acetylacetonate; The zinc salt includes any one of zinc sulfate, zinc nitrate, zinc chloride, or zinc acetate; The Ru salt is ruthenium acetylacetonate.

[0012] Preferably, the mass ratio of the M metal salt, zinc salt and dimethylimidazole is 0.1~0.6:3:6.5.

[0013] Preferably, the mass ratio of the Ru salt to the MNC substrate is 4~36:50.

[0014] Preferably, in step S2, the calcination temperature is 900 °C, and the calcination atmosphere is a 5% hydrogen-argon mixture.

[0015] Preferably, in step S4, the calcination temperature is 400 °C, and the calcination atmosphere is a 5% hydrogen-argon mixture.

[0016] A third aspect of this application provides the application of the above-mentioned low-Ru basic HER electrocatalyst or the low-Ru basic HER electrocatalyst prepared by the above preparation method in anion exchange membrane water electrolysis for hydrogen production.

[0017] Compared with the prior art, the beneficial effects of this application are as follows: In the low-Ru alkaline HER electrocatalyst of this application, metal M is anchored on nitrogen-doped carbon (NC) in unit site form to form MNC, while Ru is uniformly distributed on the MNC support in clusters of about 2 nm. Due to the interaction between Ru and MNC, a strong catalyst-support interaction is generated between the Ru clusters and MNC. At the same time, the Ru-H adsorption energy is optimized, and the oxygen-loving M further enhances the water dissociation ability, thereby improving the alkaline HER performance.

[0018] The electrocatalyst of this application has a low Ru content, with a Ru loading of only 0.08 mg / cm³ at the cathode of the anion exchange membrane electrolyzer. -2 Around [a certain amount], while ensuring catalytic activity, the cost of the catalyst is significantly reduced.

[0019] The electrocatalyst of this application exhibits excellent activity and stability in alkaline HER, with an overpotential of 10 mA cm⁻¹ in alkaline HER. -2 The lowest value is only 4 mV, and it is within 10 mA cm⁻¹. -2 After 100 hours of operation, the overpotential rise of HER was less than 10 mV. Furthermore, the electrocatalyst of this application exhibits lower cell voltage and longer-term operational stability in anion exchange membrane electrolyzers compared to commercial RuO2, achieving 1 A cm⁻¹ at 1.74 V. -2 The current density can reach 1 A cm⁻¹ -2 Stable operation for 170 hours at current density. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 TEM and XRD patterns of the Ru / Sn-NC catalyst of Example 1 and the Ru / NC catalyst of Comparative Example 3; Figure 2 The figures show the characterization results of the electronic structure and water dissociation ability of the catalysts in Example 1 and the comparative example. Figure 3The graph shows the alkaline HER performance test results of the catalysts in Example 1 and the comparative example. Figure 4 The graph shows the performance test results of the catalysts of Example 1 and Comparative Example 1 as cathode catalysts in anion exchange membrane alkaline water electrolysis cells. Detailed Implementation

[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0023] In the following description of this embodiment, the terms "including", "comprising", "having", and "containing" are all open-ended terms, meaning that they include but are not limited to.

[0024] In the following description of this embodiment, the term "and / or" is used to describe the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, B existing alone, and A and B existing simultaneously. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0025] In the following description of this embodiment, the term "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0026] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms "a" and "the" as used in the embodiments of this application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0027] Those skilled in the art should understand that, in the following description of the embodiments of this application, the sequence of numbers does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0028] Those skilled in the art will understand that the numerical ranges in the embodiments of this application should be understood as each intermediate value between the upper and lower limits of the specifically disclosed range. Each smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this application. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0029] Unless otherwise stated, the technical / scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. While this application describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this application. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0030] In a first aspect, this application provides a low-Ru alkaline HER electrocatalyst, comprising: a metal M anchored at a single site on nitrogen-doped carbon to form an MNC substrate, and Ru uniformly distributed on the MNC substrate; The metal M includes at least one of Ga, In, Sn or Sb, and the Ru is uniformly distributed in clusters on the MNC substrate.

[0031] In the low-Ru alkaline HER electrocatalyst of this application, the Ru content is 2~15 wt% and the metal M content is 1~5 wt%.

[0032] The low-Ru alkaline HER electrocatalyst of this application exhibits the following microstructure: metal M is anchored on nitrogen-doped carbon (NC) in unit site form to form MNC, while Ru is uniformly distributed on the MNC support in clusters of about 2 nm. Due to the interaction between Ru and MNC, a strong catalyst-support interaction is generated between the Ru clusters and MNC. At the same time, the Ru-H adsorption energy is optimized, and the oxygen-loving M further enhances the water dissociation ability, thereby improving the alkaline HER performance.

[0033] Furthermore, the electrocatalyst of this application has a low Ru content, with a Ru loading of only 0.08 mg cm⁻¹ at the cathode of the anion exchange membrane electrolyzer. -2 Around [a certain amount], while ensuring catalytic activity, the cost of the catalyst is significantly reduced.

[0034] Secondly, this application provides a method for preparing the aforementioned low-Ru basic HER electrocatalyst, comprising: S1, dissolve the metal salt of M and the zinc salt in methanol to obtain solution A; dissolve dimethylimidazolium in methanol to obtain solution B; mix solution A and solution B and react them, then dry the reaction product to obtain the precursor; Specifically, solutions A and B are rapidly mixed and stirred at room temperature for 24-48 hours. The solid product is collected by centrifugation and dried to obtain the precursor.

[0035] In this application, the M metal salt is selected from at least one of gallium acetylacetonate, indium acetylacetonate, tin acetylacetonate, or antimony acetylacetonate; the zinc salt includes any one of zinc sulfate, zinc nitrate, zinc chloride, or zinc acetate. The preferred mass ratio of the M metal salt, zinc salt, and dimethylimidazole is 0.1~0.6:3:6.5.

[0036] S2, the precursor is calcined to obtain the MNC substrate; Specifically, the dried precursor was calcined in a tube furnace at 900 °C for 2-4 h in a 5% hydrogen-argon mixed gas atmosphere to obtain the MNC substrate.

[0037] S3, the MNC substrate is uniformly dispersed in ethanol, then an ethanol solution of Ru salt is added, mixed evenly and evaporated to obtain the Ru-loaded MNC substrate. In this application, the Ru salt is ruthenium acetylacetonate, and the concentration of the ethanol solution of ruthenium acetylacetonate is 3~5 mg / mL, preferably 4 mg / mL.

[0038] The solid content of the MNC substrate in ethanol is 0.5~2 mg / mL, preferably 1 mg / mL.

[0039] The mass ratio of Ru salt to MNC substrate is 4~36:50.

[0040] S4. The MNC substrate loaded with Ru salt is calcined to obtain the Ru / MNC catalyst, namely the low-Ru basic HER electrocatalyst.

[0041] Specifically, the Ru-supported MNC substrate was calcined in a tube furnace at 400 °C for 2-4 h in a 5% hydrogen-argon mixed gas atmosphere to produce the Ru / MNC catalyst.

[0042] In a third aspect, the low-Ru alkaline HER electrocatalyst of this application can be used in the field of anion exchange membrane water electrolysis technology, especially in hydrogen production using anion exchange membrane electrolyzers. It exhibits excellent activity and stability in alkaline HER, with a low overpotential (10 mA cm⁻¹) in alkaline HER. -2 The lowest value is only 4 mV, and it is within 10 mA cm⁻¹. -2After 100 hours of operation, the overpotential rise of HER was less than 10 mV. Furthermore, the electrocatalyst of this application exhibits lower cell voltage and longer-term operational stability in anion exchange membrane electrolyzers compared to commercial RuO2, achieving 1 A cm⁻¹ at 1.74 V. -2 The current density can reach 1A cm⁻¹. -2 Stable operation for 170 hours at current density.

[0043] The present application will be further described below through specific embodiments.

[0044] Example 1 This embodiment provides a method for preparing a low-Ru basic HER electrocatalyst, including: S1, 0.2 g of tin acetylacetone and 3 g of zinc nitrate were dissolved in 40 mL of methanol to obtain solution A; 6.5 g of dimethylimidazole was dissolved in 80 mL of methanol to obtain solution B; solutions A and B were rapidly mixed and stirred at room temperature for 24 h, the solid phase was collected by centrifugation and dried to obtain the precursor.

[0045] S2, the precursor was calcined in a tube furnace at 900 °C for 2 h in an atmosphere of 5% hydrogen-argon mixture to obtain the Sn-NC substrate.

[0046] S3, 500 mg of Sn-NC was dispersed in 500 mL of ethanol and ultrasonically mixed for 0.5 h; then 45 mL of ethanol solution of ruthenium acetylacetonate with a concentration of 4 mg / mL was added; after uniform mixing, the solution was evaporated to dryness to obtain Sn-NC substrate loaded with ruthenium acetylacetonate. S4. The Sn-NC substrate loaded with ruthenium acetylacetone was calcined in a tube furnace at 400 °C for 2 h in an atmosphere of 5% hydrogen-argon mixture to obtain the Ru / Sn-NC catalyst.

[0047] Example 2 This embodiment provides a method for preparing a low-Ru basic HER electrocatalyst, including: S1, 0.2 g gallium acetylacetonate and 3 g zinc nitrate were dissolved in 40 mL methanol to obtain solution A; 6.5 g dimethylimidazole was dissolved in 80 mL methanol to obtain solution B; solutions A and B were rapidly mixed and stirred at room temperature for 24 h, the solid phase was collected by centrifugation and dried to obtain the precursor.

[0048] S2, the precursor was calcined in a tube furnace at 900 °C for 2 h in an atmosphere of 5% hydrogen-argon mixture to obtain the Ga-NC substrate.

[0049] S3, 500 mg of Ga-NC was dispersed in 500 mL of ethanol and ultrasonically mixed for 0.5 h; then 45 mL of ethanol solution of ruthenium acetylacetonate with a concentration of 4 mg / mL was added; after uniform mixing, the solution was evaporated to dryness to obtain Ga-NC substrate loaded with ruthenium acetylacetonate. S4. The Ga-NC substrate loaded with ruthenium acetylacetone was calcined in a tube furnace at 400 °C for 2 h in an atmosphere of 5% hydrogen-argon mixture to obtain the Ru / Ga-NC catalyst.

[0050] Example 3 This embodiment provides a method for preparing a low-Ru basic HER electrocatalyst, including: S1, 0.2 g of indium acetylacetonate and 3 g of zinc nitrate were dissolved in 40 mL of methanol to obtain solution A; 6.5 g of dimethylimidazole was dissolved in 80 mL of methanol to obtain solution B; solutions A and B were rapidly mixed and stirred at room temperature for 24 h, the solid phase was collected by centrifugation and dried to obtain the precursor.

[0051] S2, the precursor was calcined in a tube furnace at 900 °C for 2 h in an atmosphere of 5% hydrogen-argon mixture to obtain the In-NC substrate.

[0052] S3, 500 mg of In-NC was dispersed in 500 mL of ethanol and ultrasonically mixed for 0.5 h; then 45 mL of ethanol solution of ruthenium acetylacetonate with a concentration of 4 mg / mL was added; after uniform mixing, the solution was evaporated to dryness to obtain the In-NC substrate loaded with ruthenium acetylacetonate. S4. The In-NC substrate loaded with ruthenium acetylacetone was calcined in a tube furnace at 400 °C for 2 h in an atmosphere of 5% hydrogen-argon mixture to obtain the Ru / In-NC catalyst.

[0053] Example 4 This embodiment provides a method for preparing a low-Ru basic HER electrocatalyst, including: S1, 0.2 g antimony acetylacetonate and 3 g zinc nitrate were dissolved in 40 mL methanol to obtain solution A; 6.5 g dimethylimidazole was dissolved in 80 mL methanol to obtain solution B; solutions A and B were rapidly mixed and stirred at room temperature for 24 h, the solid phase was collected by centrifugation and dried to obtain the precursor.

[0054] S2, the precursor was calcined in a tube furnace at 900 °C for 2 h in an atmosphere of 5% hydrogen-argon mixture to obtain the Sb-NC substrate.

[0055] S3, 500 mg of Sb-NC was dispersed in 500 mL of ethanol and ultrasonically mixed for 0.5 h; then 45 mL of ethanol solution of ruthenium acetylacetonate with a concentration of 4 mg / mL was added; after uniform mixing, the solution was evaporated to dryness to obtain Sb-NC substrate loaded with ruthenium acetylacetonate. S4. The Sb-NC substrate loaded with ruthenium acetylacetone was calcined in a tube furnace at 400 °C for 2 h in an atmosphere of 5% hydrogen-argon mixture to obtain the Ru / Sb-NC catalyst.

[0056] Example 5 This embodiment provides a method for preparing a low-Ru basic HER electrocatalyst, including: S1, 0.1 g of tin acetylacetone and 3 g of zinc nitrate were dissolved in 40 mL of methanol to obtain solution A; 6.5 g of dimethylimidazole was dissolved in 80 mL of methanol to obtain solution B; solutions A and B were rapidly mixed and stirred at room temperature for 24 h, the solid phase was collected by centrifugation and dried to obtain the precursor.

[0057] S2, the precursor was calcined in a tube furnace at 900 °C for 2 h in an atmosphere of 5% hydrogen-argon mixture to obtain the Sn-NC substrate.

[0058] S3, 500 mg of Sn-NC was dispersed in 500 mL of ethanol and ultrasonically mixed for 0.5 h; then 10 mL of ethanol solution of ruthenium acetylacetonate with a concentration of 4 mg / mL was added; after uniform mixing, the solution was evaporated to dryness to obtain Sn-NC substrate loaded with ruthenium acetylacetonate. S4. The Sn-NC substrate loaded with ruthenium acetylacetone was calcined in a tube furnace at 400 °C for 2 h in an atmosphere of 5% hydrogen-argon mixture to obtain the Ru / Sn-NC catalyst.

[0059] Example 6 This embodiment provides a method for preparing a low-Ru basic HER electrocatalyst, including: S1, 0.6 g of tin acetylacetone and 3 g of zinc nitrate were dissolved in 40 mL of methanol to obtain solution A; 6.5 g of dimethylimidazole was dissolved in 80 mL of methanol to obtain solution B; solutions A and B were rapidly mixed and stirred at room temperature for 24 h, the solid phase was collected by centrifugation and dried to obtain the precursor.

[0060] S2, the precursor was calcined in a tube furnace at 900 °C for 2 h in an atmosphere of 5% hydrogen-argon mixture to obtain the Sn-NC substrate.

[0061] S3, 500 mg of Sn-NC was dispersed in 500 mL of ethanol and ultrasonically mixed for 0.5 h; then 90 mL of ethanol solution of ruthenium acetylacetonate with a concentration of 4 mg / mL was added; after uniform mixing, the solution was evaporated to dryness to obtain Sn-NC substrate loaded with ruthenium acetylacetonate. S4. The Sn-NC substrate loaded with ruthenium acetylacetone was calcined in a tube furnace at 400 °C for 2 h in an atmosphere of 5% hydrogen-argon mixture to obtain the Ru / Sn-NC catalyst.

[0062] Comparative Example 1 Commercial Pt / C catalysts Comparative Example 2 Commercial PtRu / C catalysts Comparative Example 3 The Ru / NC catalyst is prepared by the following methods: S1, dissolve 3g of zinc nitrate in 40 mL of methanol to obtain solution A; dissolve 6.5g of dimethylimidazole in 80 mL of methanol to obtain solution B; rapidly mix solution A and solution B, stir at room temperature for 24 h, centrifuge to collect the solid phase, and dry to obtain the precursor.

[0063] S2, the precursor was calcined in a tube furnace at 900 °C for 2 h in an atmosphere of 5% hydrogen-argon mixture to obtain the NC substrate.

[0064] S3, 500 mg of NC was dispersed in 500 mL of ethanol and ultrasonically mixed for 0.5 h; then 45 mL of ethanol solution of ruthenium acetylacetonate with a concentration of 4 mg / mL was added; after uniform mixing, the solution was evaporated to dryness to obtain the NC substrate loaded with ruthenium acetylacetonate. S4. The NC substrate loaded with ruthenium acetylacetone was calcined in a tube furnace at 400 °C for 2 h in an atmosphere of 5% hydrogen-argon mixture to obtain the Ru / NC catalyst.

[0065] 1. The morphology and phase composition of the Ru / Sn-NC catalyst prepared in Example 1, the Sn-NC substrate, and the Ru / NC catalyst in Comparative Example 3 were characterized, and the results are as follows: Figure 1 As shown. Among them, Figure 1 Figure a shows an aberration-corrected electron microscope (EM) image of Ru / Sn-NC, Figure b shows an aberration-corrected electron microscope (EM) image of Ru / Sn-NC, Figure c shows a high-resolution electron microscope (HEM) image of Ru / NC, and Figure d shows the XRD patterns of Ru / Sn-NC, Sn-NC, and Ru / NC.

[0066] from Figure 1It can be seen that after modifying the carbon substrate with metal Sn unit sites, Ru particles are uniformly distributed in small clusters on the carbon, while Ru particles in Ru / NC without metal Sn unit sites are larger, proving that there is a strong metal-support interaction between Ru and Sn-NC.

[0067] Figure 2 The figures show the characterization results of the electronic structure and water dissociation ability of the Ru / Sn-NC catalyst prepared in Example 1 and the Ru / NC catalyst in Comparative Example 3. Figure 2 Figure a shows the XANES diagrams of Ru / Sn-NC, Ru / NC, metallic Ru, and RuO2. Figure 2 Figure b shows the HER current ratios of Ru / Sn-NC and Ru / NC in D2O and H2O media.

[0068] from Figure 2 The XANES plot shows that the valence state of Ru in the Ru / Sn-NC catalyst is higher than that in Ru / NC, indicating that there is electron transfer between Ru and Sn, which increases the valence state of Ru and optimizes the Ru-H adsorption energy. Simultaneously, isotope labeling experiments demonstrate that the water dissociation ability of the Ru / Sn-NC catalyst is stronger than that of Ru / NC, proving that Ru and Sn synergistically enhance water dissociation ability, thereby improving the performance of alkaline HER.

[0069] 2. The HER performance of the catalysts in Example 1 and Comparative Examples 1-3 was tested using the following methods: (1) Preparation of catalyst slurry: 5 mg of catalyst was added to 1 mL of isopropanol solution containing 25 μL naphthol, and ultrasonicated for 30 min to obtain a uniform black catalyst slurry.

[0070] (2) Take 6 μL of the above black catalyst slurry and drop it onto a surface with an area of ​​0.196 cm². 2 It was dried on a glassy carbon electrode at room temperature.

[0071] (3) A three-electrode battery was used for testing. The glassy carbon electrode was the working electrode, the counter electrode was a carbon rod, the reference electrode was Hg / HgO, the electrolyte was 1 M KOH, and the test voltage range was -0.2-0.05 V vs .RHE.

[0072] Test results are as follows Figure 3 As shown. Figure 3 Figure a shows a comparison of the HER performance of Ru / Sn-NC, Ru / NC, PtRu / C, Pt / C, and Sn-NC. Figure 3 Figure b shows a comparison of HER stability for Ru / Sn-NC, Ru / NC, PtRu / C, and Pt / C.

[0073] from Figure 3It can be seen that the Ru / Sn-NC catalyst of Example 1 at 10 mA cm⁻¹ -2 The overpotential was only 4 mV, far lower than the 29 mV of commercial Pt / C catalyst and the 18 mV of commercial PtRu / C catalyst, and also lower than the 18 mV of the control sample Ru / NC without metal Sn doping. Meanwhile, the Ru / Sn-NC catalyst exhibited a high overpotential at 10 mA cm⁻¹. -2 Operating at a current density of [value missing] for 100 h, the overpotential increase was only about 4 mV, which is superior to commercial Pt / C and PtRu / C catalysts, and also superior to Ru / NC catalysts. The performance parameters of the catalysts prepared in Examples 1-6 are shown in Table 1.

[0074] Table 1 Performance parameters of the catalysts prepared in Examples 1-6 As shown in Table 1, the best HER performance was achieved by modifying the carbon substrate with approximately 1.9 wt% Sn metal single-atom sites and loading approximately 7.9 wt% Ru metal.

[0075] 3. The catalyst prepared in the embodiments of this application was subjected to anion exchange membrane alkaline water electrolysis test. The test method is as follows: (1) Preparation of Ru / MNC catalyst slurry: 5 mg of catalyst was added to 1 mL of a mixture of isopropanol and water containing 20 μL of naphthol, and ultrasonicated for 30 min to obtain a uniform black catalyst slurry.

[0076] (2) Preparation of RuO2 catalyst slurry: 10 mg of RuO2 was added to 2 mL of a mixed solution of isopropanol and water containing 50 μL of naphthol, and ultrasonicated for 30 min to obtain a uniform black catalyst slurry.

[0077] (3) Membrane electrode preparation: The Ru / MNC catalyst slurry was sprayed onto carbon paper, and the Ru loading was controlled at 0.08 mg / cm³. -2 The RuO2 catalyst slurry was sprayed onto nickel foam, with the RuO2 loading controlled at 1.0 mg / cm³. -2 .

[0078] (4) Assemble the foamed nickel sprayed with RuO2 catalyst, the anion exchange membrane, the carbon paper sprayed with Ru / MNC catalyst and the bipolar plate into an electrolytic cell, and test it in the battery test system. Circulate 1 M KOH solution is introduced, the test temperature is 60℃, and the test voltage range is 1.2 V-2.1 V.

[0079] As a comparison, the Pt / C of Comparative Example 1 was prepared into a slurry according to the method described in step (1) above, and sprayed onto carbon paper and nickel foam respectively, along with the RuO2 catalyst slurry prepared by the method in step (2), with a Pt loading of 0.2 mg / cm³. -2 The RuO2 loading was 1.0 mg cm. -2 Then, performance testing was conducted.

[0080] Test results are as follows Figure 4 As shown, where Figure 4 Figure a shows the alkaline membrane electrode polarization curves when Ru / Sn-NC and Pt / C catalysts are used as cathode materials, respectively. Figure 4 Figure b shows the stability curve of the alkaline membrane electrode when Ru / Sn-NC catalyst is used as the cathode material.

[0081] from Figure 4 It can be seen that when the Ru / Sn-NC catalyst is used as the cathode material, the Ru loading is only 0.08 mg cm⁻¹. -2 Below, reaching 1 A cm -2 The voltage required for the current density is 0.335 V lower than that of commercial Pt / C materials, requiring only 1.74 V. When the electrolytic cell is at 1 A cm⁻¹... -2 When operating at the current density, the voltage did not increase significantly after 170 hours, indicating that the catalyst has excellent stability when used as the cathode of an anion exchange membrane alkaline water electrolysis cell.

[0082] Although this application has been described in detail in this specification with general descriptions and specific embodiments, some modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, such modifications or improvements made without departing from the spirit of this application are all within the scope of protection claimed in this application.

Claims

1. A low-Ru alkaline HER electrocatalyst characterized in that, include: Metal M is anchored at a single site on a nitrogen-doped carbon MNC substrate, and Ru is uniformly distributed on the MNC substrate; The metal M includes at least one of Ga, In, Sn, or Sb.

2. The low-Ru alkaline HER electrocatalyst according to claim 1, characterized in that, The low-Ru alkaline HER electrocatalyst contains 2-15 wt% Ru and 1-5 wt% M.

3. The low-Ru alkaline HER electrocatalyst according to claim 1, characterized in that, The Ru is uniformly distributed in clusters on the MNC substrate.

4. The method for preparing the low-Ru alkaline HER electrocatalyst according to claim 1, characterized in that, include: S1, dissolve the metal salt M and zinc salt in methanol to obtain solution A; Dimethylimidazolium was dissolved in methanol to obtain solution B; Solution A and solution B are mixed and reacted. The reaction product is dried to obtain the precursor. S2, the precursor is calcined to obtain the MNC substrate; S3, the MNC substrate is uniformly dispersed in ethanol, then an ethanol solution of Ru salt is added, mixed evenly and evaporated to obtain the Ru-loaded MNC substrate. S4. The MNC substrate loaded with Ru salt is calcined to obtain the Ru / MNC catalyst, namely the low-Ru basic HER electrocatalyst.

5. The preparation method according to claim 4, characterized in that, The M metal salt includes at least one of gallium acetylacetonate, indium acetylacetonate, tin acetylacetonate, or antimony acetylacetonate. The zinc salt includes any one of zinc sulfate, zinc nitrate, zinc chloride, or zinc acetate; The Ru salt is ruthenium acetylacetonate.

6. The preparation method according to claim 4, characterized in that, The mass ratio of the M metal salt, zinc salt, and dimethylimidazole is 0.1~0.6:3:6.

5.

7. The preparation method according to claim 4, characterized in that, The mass ratio of Ru salt to MNC substrate is 4~36:

50.

8. The preparation method according to claim 4, characterized in that, In step S2, the calcination temperature is 800 to 1000°C, and the calcination atmosphere is a 5% hydrogen-argon mixture.

9. The preparation method according to claim 4, characterized in that, In step S4, the calcination temperature is 300 to 500°C, and the calcination atmosphere is a 5% hydrogen-argon mixture.

10. The application of the low-Ru basic HER electrocatalyst according to any one of claims 1-3 or the low-Ru basic HER electrocatalyst prepared by the preparation method according to any one of claims 4-9 in anion exchange membrane water electrolysis for hydrogen production.

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