Alkaline hydrogen evolution catalyst and preparation method and application thereof

Abstract

The invention provides an alkaline hydrogen evolution catalyst and a preparation method and application thereof.The alkaline hydrogen evolution catalyst comprises a carrier and an active substance loaded on the carrier, the carrier comprises reduced graphene oxide, and the active substance comprises boron-oxygen double-coordinated ruthenium clusters. According to the catalyst provided by the invention, the boron-oxygen double-coordinated ruthenium clusters and the reduced graphene oxide interact, so that the ruthenium clusters can be uniformly distributed on the surface of the reduced graphene oxide and are not easy to agglomerate under the condition of high density, and the ruthenium clusters have relatively small sizes and can provide more active sites; the activity and the stability of the ruthenium-based catalyst for hydrogen production through water electrolysis in an alkaline environment are improved to a great extent; in addition, the preparation method provided by the invention is simple and suitable for large-scale application.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydrogen production by electrolysis of water, and relates to an alkaline hydrogen evolution catalyst and a preparation method and application thereof. Background Art

[0002] Green hydrogen (H2) is a carbon-free energy source for the operation of future energy systems. Currently, efficient hydrogen production has become a major and urgent issue. The use of renewable energy to produce hydrogen faces two major challenges: first, the cost of catalysts remains high, especially in the hydrogen evolution reaction (HER), where platinum (Pt), a precious metal, still dominates; second, proton exchange membrane water electrolyzers (PEMWEs) have excellent adaptability to the operating conditions of renewable energy systems, and their industrial technology has reached a fairly mature level. However, in the harsh acidic reaction environment, the operation and maintenance costs of PEMWEs are high, and this problem is difficult to effectively solve. Therefore, it has become a top priority to explore low-cost and more efficient catalysts that are more suitable for the next generation of anion exchange membrane water electrolyzer (AEMWE) systems.

[0003] Ruthenium (Ru) has attracted much attention in the production of hydrogen via water electrolysis under alkaline conditions due to its low cost and superior performance to traditional platinum-based catalysts. However, many unresolved issues remain with Ru-based catalysts under alkaline hydrogen evolution reaction (HER) conditions. First, Ru-based catalysts suffer from insufficient HER activity. Second, due to the weak interaction between the metal and the support, Ru metal easily agglomerates, resulting in poor performance in long-term and high current density tests at an industrial scale.

[0004] Currently, ruthenium cluster catalysts prepared by chemical reduction or high-temperature calcination are difficult to control particle size and difficult to prepare at high density. This results in no significant improvement in hydrogen evolution reaction kinetics, mass activity, or electrolyzer performance, and their inherent flaws remain largely unaddressed. Due to the ruthenium cluster catalyst's tendency to agglomerate and low metal site activity, its electrocatalytic hydrogen evolution activity is poor, and its performance in long-term electrolyzer tests is unsatisfactory.

[0005] Therefore, how to prepare a small-sized, high-density and uniformly distributed ruthenium cluster catalyst is a technical problem that needs to be solved urgently. Summary of the Invention

[0006] To address the shortcomings of the prior art, the present invention aims to provide an alkaline hydrogen evolution catalyst, its preparation method, and its application. In the catalyst provided by the present invention, boron-oxygen-double-coordinated ruthenium clusters interact with reduced graphene oxide, enabling uniform distribution of the ruthenium clusters on the surface of the reduced graphene oxide. These clusters are less likely to agglomerate even at high densities. Furthermore, the smaller size of the ruthenium clusters provides more active sites, significantly improving the HER activity and stability of the ruthenium-based catalyst in alkaline environments. Furthermore, the preparation method provided by the present invention is simple and suitable for large-scale applications.

[0007] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides an alkaline hydrogen evolution catalyst, comprising a carrier and an active substance supported on the carrier, wherein the carrier comprises reduced graphene oxide, and the active substance comprises a boron-oxygen bidentated ruthenium cluster.

[0009] In the present invention, there is a strong interaction between the boron-oxygen dual-coordinated ruthenium clusters and reduced graphene oxide. This strong interaction can firmly anchor the ruthenium clusters to the graphene surface, reduce migration and aggregation between clusters, thereby improving the dispersion of ruthenium and exposing more active sites. In addition, the electronic interaction between boron, oxygen, and ruthenium optimizes the electronic structure of ruthenium, making the ruthenium clusters more ideal for adsorption and desorption of hydrogen intermediates, reducing the reaction energy barrier of the HER, and increasing the reaction rate. In contrast, the binding strength between single oxygen- or boron-coordinated ruthenium clusters and reduced graphene oxide is relatively weak, making the ruthenium clusters more likely to fall off or agglomerate during use. Moreover, when only boron or oxygen is coordinated, the regulation of the ruthenium electron cloud distribution and energy level is relatively simple, resulting in insufficient activity and not as significant as the effect of boron-oxygen dual-coordinated ruthenium on improving HER performance.

[0010] 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.

[0011] Preferably, based on the mass of the alkaline hydrogen evolution catalyst as 100 wt%, the loading amount of the ruthenium cluster is 7 wt% to 13 wt%, for example, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt% or 13 wt%, etc., but is not limited to the listed values, and other values not listed within the numerical range are also applicable.

[0012] In the present invention, by controlling the loading amount of ruthenium clusters within the above preferred range, it is more conducive to balancing the catalyst cost and performance.

[0013] Preferably, the average size of the ruthenium clusters is 2.1 nm to 3 nm, for example, 2.1 nm, 2.2 nm, 2.3 nm, 2.4 nm, 2.5 nm, 2.6 nm, 2.7 nm, 2.8 nm, 2.9 nm or 3 nm, but is not limited to the listed values, and other unlisted values within this numerical range are also applicable.

[0014] In the present invention, small-sized ruthenium clusters can expose more active sites, which means that the number of hydrogen evolution sites that can participate in the reaction per unit time is increased, thereby further improving the performance of HER.

[0015] Preferably, based on the mass of the alkaline hydrogen evolution catalyst as 100 wt%, the mass proportion of boron is 0.01 wt% to 0.1 wt%, for example, 0.01 wt%, 0.02 wt%, 0.03 wt%, 0.04 wt%, 0.05 wt%, 0.06 wt%, 0.07 wt%, 0.08 wt%, 0.09 wt% or 0.1 wt%, etc., but is not limited to the enumerated values, and other values not listed within the numerical range are also applicable.

[0016] In the present invention, by controlling the mass proportion of boron within the above-mentioned preferred range, it is more conducive to the performance of the boron-oxygen double coordination synergistic effect. If the mass proportion of boron is large, the lattice structure of the ruthenium cluster will be distorted, weakening the binding force between the ruthenium cluster and the reduced graphene oxide surface, which is not conducive to the uniform dispersion of the ruthenium cluster on the reduced graphene oxide surface. At the same time, when the mass proportion of boron is too large, boron will completely replace the coordination sites of oxygen. At this time, the ruthenium cluster in the catalyst has only boron coordination, and the catalyst hydrogen evolution reaction activity cannot be fully exerted. On the contrary, if the mass proportion of boron is too small, boron is difficult to play a regulatory role in the electronic structure and surface properties of the ruthenium cluster, which is not conducive to the redistribution of the electron cloud of the ruthenium cluster and orbital hybridization.

[0017] Preferably, the number of layers of the reduced graphene oxide is 1 to 5, such as 1, 2, 3, 4 or 5 layers, but is not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0018] In a second aspect, the present invention provides a method for preparing the alkaline hydrogen evolution catalyst as described in the first aspect, the preparation method comprising: mixing a ruthenium source, a boron source, graphene oxide and a solvent, performing a solvothermal reaction, filtering to obtain a precursor, and performing a reduction reaction to obtain the alkaline hydrogen evolution catalyst.

[0019] In the present invention, the graphene oxide surface has abundant oxygen-containing functional groups, which can provide a large number of adjustable anchoring sites. Under solvothermal conditions, these functional groups will coordinate with ruthenium ions or boron-oxygen polymers in the solution, forming a high-density ruthenium cluster catalyst precursor with a boron-oxygen double coordination on the graphene oxide surface. Subsequent reduction reaction partially reduces the oxygen-containing functional groups on the graphene oxide surface. The reduced graphene oxide has better conductivity and chemical stability, which is conducive to the subsequent loaded boron-oxygen double coordination ruthenium clusters to exert catalytic performance. At the same time, the ruthenium clusters loaded on the graphene oxide surface will also be reduced from high-valent ruthenium ions to low-valent ruthenium nanoparticles. During the reduction process, the boron-oxygen double coordination structure stabilizes the ruthenium clusters, avoiding the occurrence of ruthenium cluster agglomeration during the reduction process. This loading process is conducive to the ruthenium clusters being evenly distributed on the graphene oxide surface, improving the stability and dispersibility of the ruthenium clusters.

[0020] Preferably, the ruthenium source comprises ruthenium chloride, and the boron source comprises boric acid.

[0021] Preferably, the mixing includes ultrasound, and the ultrasound time is 1.5h to 2.5h, for example, 1.5h, 1.8h, 2h, 2.3h or 2.5h, etc., but is not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0022] Preferably, the temperature of the solvothermal reaction is 160°C to 200°C, for example, 160°C, 165°C, 170°C, 175°C, 180°C, 185°C, 190°C, 195°C or 200°C, but is not limited to the listed values, and other unlisted values within this numerical range are also applicable.

[0023] Preferably, the solvent thermal reaction time is 10 h to 14 h, such as 10 h, 11 h, 12 h, 13 h or 14 h, etc., but is not limited to the listed values, and other values not listed within the numerical range are also applicable.

[0024] In the present invention, by controlling the temperature of the solvothermal reaction within the above-mentioned preferred range, the solvothermal reaction is more conducive to proceeding, and the size of the ruthenium clusters can be adjusted by regulating the temperature and time of the solvothermal reaction.

[0025] Preferably, the filtration comprises vacuum filtration.

[0026] Preferably, after the filtration, the filtered product is washed and dried in sequence.

[0027] Preferably, the drying comprises freeze-drying.

[0028] In the present invention, freeze-drying is more conducive to maintaining the morphology of reduced graphene oxide than vacuum drying, avoiding curling or stacking of the reduced graphene oxide sheet structure, or migration and agglomeration of ruthenium clusters on the carrier surface, which affect the performance of the material; at the same time, freeze-drying can also ensure that ruthenium will not be oxidized during the drying process, which is beneficial to the performance of the catalyst.

[0029] Preferably, the freeze-drying time is 20 h to 25 h, for example, 20 h, 21 h, 22 h, 23 h, 24 h or 25 h, etc., but is not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0030] Preferably, the reducing atmosphere comprises a combined atmosphere of hydrogen and argon.

[0031] Preferably, based on the volume of the combined atmosphere of hydrogen and argon being 100%, the volume proportion of hydrogen is 4% to 6%, for example, 4%, 4.5%, 5%, 5.5% or 6%, etc., but is not limited to the listed values, and other unlisted values within this numerical range are also applicable.

[0032] Preferably, the temperature of the reduction reaction is 400°C to 600°C, such as 400°C, 450°C, 500°C, 550°C or 600°C, but is not limited to the listed values. Other values not listed within the numerical range are also applicable.

[0033] In the present invention, by controlling the reduction temperature at 400° C. to 600° C., it can be ensured that ruthenium is fully reduced without agglomeration, and the structure of the reduced graphene oxide will not collapse or be destroyed due to excessively high temperature.

[0034] Preferably, the heating rate of the reduction reaction is 2°C / min to 5°C / min, for example, 2°C / min, 3°C / min, 4°C / min or 5°C / min, but is not limited to the listed values, and other values not listed within the numerical range are also applicable.

[0035] In the present invention, by controlling the heating rate of the reduction reaction within the above preferred range, it is more conducive to the full reduction of the catalyst, thereby avoiding the collapse of the catalyst structure caused by an excessively fast heating rate.

[0036] Preferably, the insulation time of the reduction reaction is 1.5h to 2.5h, for example, 1.5h, 1.6h, 1.7h, 1.8h, 1.9h, 2h, 2.1h, 2.2h, 2.3h, 2.4h or 2.5h, etc., but is not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0037] In a third aspect, the present invention provides a use of the alkaline hydrogen evolution catalyst as described in the first aspect or the alkaline hydrogen evolution catalyst prepared by the preparation method as described in the second aspect in hydrogen production by water electrolysis.

[0038] Preferably, the method for producing hydrogen by water electrolysis includes an anion exchange membrane water electrolysis method for producing hydrogen.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] In the catalyst provided by the present invention, boron-oxygen dual-coordinated ruthenium clusters interact with reduced graphene oxide, allowing the ruthenium clusters to be evenly distributed on the surface of the reduced graphene oxide and not easily agglomerated even at high density. Furthermore, the ruthenium clusters have a smaller size and can provide more active sites, thereby significantly improving the HER activity and stability of the ruthenium-based catalyst in an alkaline environment. Furthermore, the preparation method provided by the present invention is simple, which is conducive to large-scale application. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a schematic diagram of the preparation process provided in Example 1.

[0042] Figure 2 TEM images of the precursor and alkaline hydrogen evolution catalyst prepared in Example 1.

[0043] Figure 3 TEM images of the alkaline hydrogen evolution catalyst prepared in Example 1 at different magnifications.

[0044] Figure 4 TEM images of the alkaline hydrogen evolution catalyst prepared in Comparative Example 1 at different magnifications are shown.

[0045] Figure 5 TEM images of the alkaline hydrogen evolution catalyst prepared in Comparative Example 2 at different magnifications are shown.

[0046] Figure 6 1 is the XRD pattern of the precursor and alkaline hydrogen evolution catalyst prepared in Example 1.

[0047] Figure 7 1 is the XRD pattern of the alkaline hydrogen evolution catalysts prepared in Example 1, Comparative Example 1 and Comparative Example 2.

[0048] Figure 8 3 and 4 and the LSV polarization curves of the alkaline hydrogen evolution catalysts prepared in Example 1, Comparative Example 3 and Comparative Example 4 and 20% Pt / C in an alkaline environment.

[0049] Figure 9 It is a bar graph of the overpotential of the alkaline hydrogen evolution catalyst prepared in Example 1 and Comparative Example 3 and 20% Pt / C at different current densities.

[0050] Figure 10 It is a Tafel slope graph of the alkaline hydrogen evolution catalyst prepared in Example 1 and Comparative Example 3 and 20% Pt / C.

[0051] Figure 11 3 and 4, and the electrochemical impedance spectroscopy of the alkaline hydrogen evolution catalysts prepared in Example 1, Comparative Example 3, and Comparative Example 4, and 20% Pt / C.

[0052] Figure 12 2 are LSV polarization curves of the alkaline hydrogen evolution catalysts prepared in Comparative Example 1 and Comparative Example 2.

[0053] Figure 13 It is a bar graph of the overpotential of the alkaline hydrogen evolution catalysts prepared in Comparative Example 1 and Comparative Example 2 at different current densities.

[0054] Figure 14 1 is a comparison diagram of the LSV polarization curves of the alkaline hydrogen evolution catalysts prepared in Example 1, Comparative Example 1 and Comparative Example 2 before and after 5000 CV cycles.

[0055] Figure 15 It is a bar graph of the overpotential of the alkaline hydrogen evolution catalysts prepared in Example 1, Comparative Example 1 and Comparative Example 2 before and after different current densities and different CV cycle numbers.

[0056] Figure 16 The alkaline hydrogen evolution catalyst prepared in Example 1 and 20% Pt / C were tested at 100 mA / cm 2 Constant current performance diagram under current density;

[0057] Figure 17 1 is the LSV polarization curve of the alkaline hydrogen evolution catalyst in Application Examples 1-4 at different temperatures.

[0058] Figure 18 This is the LSV polarization curve of the alkaline hydrogen evolution catalyst and 20% Pt / C in Application Example 1.

[0059] Figure 19 This is a long-term stability test chart of Application Example 1. DETAILED DESCRIPTION

[0060] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0061] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0062] Example 1

[0063] This embodiment provides an alkaline hydrogen evolution catalyst, comprising a carrier reduced graphene oxide and a boron-oxygen-double-coordinated ruthenium cluster supported on the reduced graphene oxide, wherein the loading amount of the ruthenium cluster is 9.54wt%, the mass proportion of boron in the catalyst is 0.04wt%, and the preparation method is as follows: Figure 1 As shown, the specific process is as follows:

[0064] (1) 154 μL of RuCl₃ solution (28.6 mg / mL), 50 mg of H₃BO₃, and 7.5 mL of GO aqueous solution (5 mg / mL) were added to 30 mL of deionized water, and the mixture was then sonicated for 2 h. Subsequently, the resulting solution was transferred to a 100 mL Teflon-lined stainless steel autoclave and heated at 180°C for 12 h. After the autoclave cooled to room temperature, the synthesized compound was washed three times with deionized water and ethanol, and the filtered product was freeze-dried for 24 h to obtain the precursor.

[0065] (2) The precursor was placed in a H2 / Ar (5 / 95% vol%) atmosphere, heated to 500°C at a heating rate of 5°C / min, and kept at this temperature for 2 h to obtain an alkaline hydrogen evolution catalyst.

[0066] Example 2

[0067] This embodiment provides an alkaline hydrogen evolution catalyst, comprising a carrier reduced graphene oxide and a boron-oxygen-double-coordinated ruthenium cluster supported on the reduced graphene oxide, wherein the loading amount of the ruthenium cluster is 7 wt %, and the mass proportion of boron in the catalyst is 0.01 wt %. The preparation method is as follows:

[0068] (1) 115 μL of RuCl₃ solution (28.6 mg / mL), 12.5 mg of H₃BO₃, and 7.5 mL of GO aqueous solution (5 mg / mL) were added to 30 mL of deionized water, and the mixture was then sonicated for 1.5 h. Subsequently, the resulting solution was transferred to a 100 mL Teflon-lined stainless steel autoclave and heated at 160°C for 10 h. After the autoclave cooled to room temperature, the synthesized compound was washed three times with deionized water and ethanol, and the filtered product was freeze-dried for 20 h to obtain the precursor.

[0069] (2) The precursor was placed in a H2 / Ar (4 / 96% vol%) atmosphere, heated to 400°C at a heating rate of 2°C / min, and kept at this temperature for 2.5 h to obtain an alkaline hydrogen evolution catalyst.

[0070] Example 3

[0071] This embodiment provides an alkaline hydrogen evolution catalyst, comprising a carrier reduced graphene oxide and a boron-oxygen-double-coordinated ruthenium cluster supported on the reduced graphene oxide, wherein the loading amount of the ruthenium cluster is 13 wt %, and the mass proportion of boron in the catalyst is 0.1 wt %. The preparation method is as follows:

[0072] (1) 210 μL of RuCl₃ solution (28.6 mg / mL), 125 mg of H₃BO₃, and 7.5 mL of GO aqueous solution (5 mg / mL) were added to 30 mL of deionized water, and the mixture was then sonicated for 2.5 h. Subsequently, the resulting solution was transferred to a 100 mL Teflon-lined stainless steel autoclave and heated at 200°C for 14 h. After the autoclave cooled to room temperature, the synthesized compound was washed three times with deionized water and ethanol, and the filtered product was freeze-dried for 25 h to obtain the precursor.

[0073] (2) The precursor was placed in a H2 / Ar (6 / 94%, vol%) atmosphere, heated to 600°C at a heating rate of 4°C / min, and kept at this temperature for 1.5 h to obtain an alkaline hydrogen evolution catalyst.

[0074] Example 4

[0075] The difference between this embodiment and embodiment 1 is that, in this embodiment, the mass proportion of B in the catalyst is 0.005 wt %, and in step (1) of the preparation method, 6.25 mg of H3BO3 is added;

[0076] The rest of the preparation methods and parameters were the same as those in Example 1.

[0077] Example 5

[0078] The difference between this embodiment and embodiment 1 is that, in this embodiment, the mass proportion of B in the catalyst is 0.2 wt %, and in step (1) of the preparation method, 250 mg of H3BO3 is added;

[0079] The rest of the preparation methods and parameters were the same as those in Example 1.

[0080] Example 6

[0081] The difference between this embodiment and embodiment 1 is that, in this embodiment, the mass proportion of Ru in the catalyst is 6 wt %, and in step (1) of the preparation method, 95 μL of RuCl 3 solution is added;

[0082] The rest of the preparation methods and parameters were the same as those in Example 1.

[0083] Example 7

[0084] The difference between this embodiment and embodiment 1 is that, in this embodiment, the mass proportion of Ru in the catalyst is 15 wt %, and in step (1) of the preparation method, 240 μL of RuCl 3 solution is added;

[0085] The rest of the preparation methods and parameters were the same as those in Example 1.

[0086] Example 8

[0087] The difference between this embodiment and embodiment 1 is that, in this embodiment, in step (1) of the preparation method, vacuum drying is adopted;

[0088] The rest of the preparation methods and parameters were the same as those in Example 1.

[0089] Example 9

[0090] The difference between this embodiment and embodiment 1 is that, in this embodiment, in step (2) of the preparation method, heating is performed to 650°C at a heating rate of 5°C / min;

[0091] The rest of the preparation methods and parameters were the same as those in Example 1.

[0092] Example 10

[0093] The difference between this embodiment and embodiment 1 is that, in this embodiment, in step (2) of the preparation method, heating to 500° C. is performed at a heating rate of 6° C. / min;

[0094] The rest of the preparation methods and parameters were the same as those in Example 1.

[0095] Comparative Example 1

[0096] The difference between this comparative example and Example 1 is that in this comparative example, the catalyst includes a carrier reduced graphene oxide and a boron-coordinated ruthenium cluster supported on the reduced graphene oxide, wherein the loading amount of the ruthenium cluster is 9.57 wt %, the mass proportion of boron in the catalyst is 0.96 wt %, and in step (1) of the preparation method, 2 g of H3BO3 is added;

[0097] The rest of the preparation methods and parameters were the same as those in Example 1.

[0098] Comparative Example 2

[0099] The difference between this comparative example and Example 1 is that in this comparative example, the catalyst comprises a carrier reduced graphene oxide and oxygen-coordinated ruthenium clusters supported on the reduced graphene oxide, wherein the loading amount of the ruthenium clusters is 9.65 wt %. In step (1) of the preparation method, H3BO3 is not added;

[0100] The rest of the preparation methods and parameters were the same as those in Example 1.

[0101] Comparative Example 3

[0102] The difference between this comparative example and Example 1 is that in this comparative example, the catalyst includes a carrier graphene and ruthenium clusters supported on the graphene, wherein the loading amount of the ruthenium clusters is 1.21 wt %. In the preparation method step (1), the graphene oxide aqueous solution is replaced by a graphene aqueous solution;

[0103] The rest of the preparation methods and parameters were the same as those in Example 1.

[0104] Comparative Example 4

[0105] The difference between this comparative example and Example 1 is that in this comparative example, the catalyst only includes the support, and in step (1) of the preparation method, no RuCl3 solution is added;

[0106] The rest of the preparation methods and parameters were the same as those in Example 1.

[0107] Comparative Example 5

[0108] The difference between this comparative example and Example 1 is that in this comparative example, the catalyst comprises a carrier reduced graphene oxide and a nitrogen-oxygen-double-coordinated ruthenium cluster supported on the reduced graphene oxide; in step (1) of the preparation method, H3BO3 is replaced by urea;

[0109] The rest of the preparation methods and parameters were the same as those in Example 1.

[0110] Application Example 1

[0111] In an anion exchange membrane electrolyzer, water electrolysis was performed at 80° C. to produce hydrogen using the alkaline hydrogen evolution catalyst prepared in Example 1 as the cathode, IrO 2 as the anode, Fumasep FAA-3-PK-130 as the anion exchange membrane, and 1 M KOH aqueous solution as the electrolyte.

[0112] Application Example 2

[0113] The difference between this application example and application example 1 is that the temperature in this application example is 20°C;

[0114] The rest of the preparation methods and parameters were consistent with those in Application Example 1.

[0115] Application Example 3

[0116] The difference between this application example and application example 1 is that the temperature in this application example is 40°C;

[0117] The rest of the preparation methods and parameters were consistent with those in Application Example 1.

[0118] Application Example 4

[0119] The difference between this application example and application example 1 is that the temperature in this application example is 60°C;

[0120] The rest of the preparation methods and parameters were consistent with those in Application Example 1.

[0121] Performance Testing

[0122] The alkaline hydrogen evolution catalysts prepared in Examples 1-10 and Comparative Examples 1-5 and the 20% Pt / C catalyst were respectively coated on a glassy carbon electrode as a working electrode, a Hg / HgO electrode as a reference electrode, a platinum electrode as a counter electrode, and a 1 M KOH aqueous solution as an electrolyte. Electrochemical tests were performed, and the test results are shown in Table 1. Corresponding tests were performed using Examples 1-4 and 20% Pt / C, and the test results are shown in Table 2.

[0123] Table 1

[0124]

[0125]

[0126] Table 2

[0127]

[0128] Figure 2 (a) is the catalyst precursor prepared in Example 1, Figure 2 (b) is the final product alkaline hydrogen evolution catalyst prepared in Example 1. It can be seen that the boron-oxygen-coordinated ruthenium cluster intermediate is uniformly distributed on the support, and the ruthenium clusters in the final product are also uniformly distributed on the support, which shows that the preparation method provided by the present invention successfully produces a ruthenium cluster catalyst with small size, high density and uniform distribution; Figure 3 、 Figure 4 and Figure 5 It can be seen from the comparison that the ruthenium cluster catalyst with boron-oxygen dual coordination has a more uniform distribution of ruthenium clusters on the support than the ruthenium cluster catalyst with only boron or oxygen coordination; Figure 6 and Figure 7 It can be seen that in the catalyst prepared by the present invention, ruthenium exists in the form of ruthenium element.

[0129] Depend on Figures 8-16As can be seen from the data comparison of Example 1 and Comparative Examples 1-4 in Table 1, in the present invention, the performance and stability of catalysts with only boron or oxygen monocoordination are inferior to those with boron-oxygen bicoordination. Moreover, since there are no oxygen-containing groups on the graphene surface, boric acid cannot effectively form intermediates during the solvothermal process, and thus boron-oxygen bicoordination ruthenium clusters cannot be obtained. In addition, the hydrophilicity of graphene itself is not as good as that of reduced graphene oxide. Therefore, the loading of Ru catalyst prepared using graphene is greatly reduced, resulting in a significant decrease in its HER performance. As can be seen from the data comparison of Example 1 and Comparative Example 5 in Table 1, the performance of nitrogen-oxygen bicoordination ruthenium cluster catalysts is not as good as that of boron-oxygen bicoordination ruthenium cluster catalysts when used for alkaline water electrolysis to produce hydrogen.

[0130] Depend on Figure 17-Figure 19 As can be seen from the data comparison in Table 2, the alkaline hydrogen evolution catalyst provided by the present invention requires a small cell voltage at different temperatures, reaching the lowest at 80°C. The required cell voltage is even lower than that of 20% Pt / C, and it exhibits excellent stability under long-term testing at 80°C, which indicates that the catalyst prepared in the present application can be preferably used in anion exchange membrane water electrolyzers.

[0131] From the comparison of the data of Example 1 with Examples 4-7 in Table 1, it can be seen that by controlling the mass ratio of B and O in the catalyst within the preferred range of the present invention, the catalyst can exhibit better performance; from the comparison of the data of Example 1 with Examples 8-10 in Table 1, it can be seen that in the present invention, by using vacuum drying and controlling the reduction temperature and reduction rate within the preferred range of the present invention, the performance of the catalyst can also be further improved.

[0132] 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 basic hydrogen evolution catalyst, characterized in that The alkaline hydrogen evolution catalyst comprises a carrier and an active substance supported on the carrier, wherein the carrier comprises reduced graphene oxide, and the active substance comprises a boron-oxygen double-coordinated ruthenium cluster.

2. The alkaline hydrogen evolution catalyst according to claim 1, wherein Based on 100 wt% of the mass of the alkaline hydrogen evolution catalyst, the loading amount of the ruthenium cluster is 7 wt% to 13 wt%.

3. The alkaline hydrogen evolution catalyst according to claim 1 or 2, characterized in that The average size of the ruthenium clusters is 2.1 nm to 3 nm.

4. The alkaline hydrogen evolution catalyst according to any one of claims 1 to 3, characterized in that Based on 100 wt% of the mass of the alkaline hydrogen evolution catalyst, the mass proportion of the boron is 0.01 wt% to 0.1 wt%.

5. The alkaline hydrogen evolution catalyst according to any one of claims 1 to 4, characterized in that The number of layers of the reduced graphene oxide is 1 to 5.

6. A method for preparing the alkaline hydrogen evolution catalyst according to any one of claims 1 to 5, characterized in that: The preparation method comprises: mixing a ruthenium source, a boron source, graphene oxide and a solvent, performing a solvent thermal reaction, filtering to obtain a precursor, and performing a reduction reaction to obtain the alkaline hydrogen evolution catalyst.

7. The method for preparing the alkaline hydrogen evolution catalyst according to claim 6, wherein The ruthenium source includes ruthenium chloride, and the boron source includes boric acid; Preferably, the mixing includes ultrasound, and the ultrasound time is 1.5h to 2.5h; Preferably, the temperature of the solvent thermal reaction is 160°C to 200°C; Preferably, the solvent thermal reaction time is 10 h to 14 h.

8. The method for preparing the alkaline hydrogen evolution catalyst according to claim 6 or 7, wherein: The filtration includes vacuum filtration; Preferably, after the filtration, the filtered product is washed and dried in sequence; Preferably, the drying comprises freeze drying; Preferably, the freeze-drying time is 20 h to 25 h.

9. The method for preparing the alkaline hydrogen evolution catalyst according to any one of claims 6 to 8, wherein: The reducing atmosphere includes a combined atmosphere of hydrogen and argon; Preferably, the volume proportion of the hydrogen gas is 4% to 6% based on the volume of the combined atmosphere of hydrogen and argon being 100%; Preferably, the temperature of the reduction reaction is 400°C to 600°C; Preferably, the heating rate of the reduction reaction is 2°C / min to 5°C / min; Preferably, the insulation time of the reduction reaction is 1.5h to 2.5h.

10. Use of the alkaline hydrogen evolution catalyst according to any one of claims 1 to 5 or the alkaline hydrogen evolution catalyst prepared by the preparation method according to any one of claims 6 to 9 in hydrogen production by water electrolysis; Preferably, the method for producing hydrogen by water electrolysis includes an anion exchange membrane water electrolysis method for producing hydrogen.

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