A 1T-MoS2-loaded ruthenium single-atom lattice catalyst and its preparation method

Abstract

The present invention discloses a 1T-MoS₂ supported ruthenium single-atom array catalyst and a preparation method thereof. The 1T-MoS₂ supported Ru single-atom array catalyst includes: a substrate, a metal 1T-MoS₂ layer coated on the substrate, and a Ru single-atom array supported on the surface of the metal 1T-MoS₂ layer. Among them, relative to 100 g of the 1T-MoS₂ supported Ru single-atom array catalyst, the mass content of Mo atoms is 6.5-8.5 wt.%, and the mass content of Ru atoms is 0.04-0.11 wt.%. The reaction conditions of the present invention are mild, the requirements for equipment are low, and it is simple and low-cost. For the 1T-MoS₂ supported Ru single-atom array catalyst prepared by the present invention, the loading amount of Ru in the electrode is less than 0.11 wt.%, and its performance in electrocatalytic water splitting in 1.0 M KOH exceeds that of the Pt / C catalyst, having great commercial application value.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrocatalytic hydrogen production, and particularly relates to a 1T-MoS2 supported ruthenium single-atom array catalyst and a preparation method thereof. Background Art

[0002] Different from traditional fossil fuels, hydrogen can generate heat energy through combustion or be converted into electrical energy through an electrochemical reaction in a fuel cell. Whether it is for heat generation or power generation, the by-product is only water, and no greenhouse gases or other polluting gases are produced. Therefore, hydrogen is considered an important clean energy carrier. Electrolyzing water to produce hydrogen using green energy such as photovoltaic power generation, wind power generation, and solar power generation is of great significance for reducing the emission of greenhouse gases such as carbon dioxide and achieving the "dual carbon" goal.

[0003] Electrolytic water hydrogen production can be roughly divided into two different processes. The first is the oxygen evolution reaction (OER) that occurs at the anode, and the other is the hydrogen evolution reaction (HER) that occurs at the cathode. Developing a highly active catalyst system with a low overpotential is of great significance for improving the actual efficiency of electrolytic water, thereby reducing the power consumption during electrolytic water production and is one of the hot research topics worldwide.

[0004] In the current electrolytic water hydrogen production technology, the alkaline electrolyzer technology is the most mature and has the lowest production cost. However, there are no directly available protons in alkaline electrolyzed water, and an additional water molecule cleavage reaction needs to be introduced, which makes the alkaline HER activity of the catalyst 2-3 orders of magnitude lower than that in an acidic environment under the same conditions. There is still room for improvement in the performance of existing catalysts, and developing high-performance and low-cost alkaline hydrogen evolution catalysts is a problem that needs to be solved.

[0005] Due to the advantages of its metallic properties, metallic MoS2 is the best electrocatalyst among the common phases of MoS2. It has been confirmed that both its S-edge and basal plane have HER catalytic activity, and its catalytic activity is superior to that of 2H-phase and 3R-phase MoS2. Ru is the cheapest platinum group metal, with a cost only about one-tenth of Pt, and it has a hydrogen adsorption free energy close to that of Pt. Therefore, researchers have studied catalysts prepared by loading noble metal Ru on MoS2 as a carrier. For example, CN202311679833 discloses a Ru-doped hollow tubular MoS2 catalytic material and its preparation method, which is used to activate PMS to degrade organic pollutants in water. CN201911347186 discloses a device and method for continuously preparing a carbon nanotube fiber composite electrolytic water hydrogen evolution catalyst. In this invention, catalyst particles with catalytic properties such as rubidium oxide and MoS2 are mixed into the electroplating solution and electroplated on the carbon nanotube fiber. CN116536697A publishes a Ru-based single-atom alloy electrocatalyst and its preparation method and application. Using a pre-activated carbon fiber paper as the substrate, transition metal single atoms are anchored on the carbon substrate through one-step pulse electrodeposition, and the Ru-based single-atom alloy electrocatalyst is obtained by coupling this transition metal single-atom anchored carbon structure with ultra-small Ru nanocrystals. However, its single atoms agglomerate severely and are poorly dispersed, making it difficult to maximize the catalytic effect of noble metal Ru. CN116288475A discloses a preparation method of a Ru-based single-atom catalyst. A salt solution is obtained by mixing a tungsten salt, a ruthenium salt, and a morphology regulator in a solvent, and nickel foam is added to the salt solution for hydrothermal reaction to obtain a precursor material; then the precursor material is coated with an organic substance to obtain a coated material; and then the coated material is annealed to obtain a Ru-based single-atom catalyst. Its preparation process involves multiple steps, is complex and difficult to control, is not suitable for large-scale preparation, and has a large Ru loading, but the atomic dispersion degree is low, and the catalytic effect of the noble metal is not fully exerted.

[0006] In addition, Zhang Junmeng (Research on the Preparation and Electrochemical Hydrogen Evolution Performance of Single-Atom Ruthenium-Doped Molybdenum Disulfide Catalysts, Master's Thesis of Beijing University of Chemical Technology, June 12, 2020) conducted a detailed study on single-atom ruthenium-doped molybdenum disulfide catalysts. The prepared catalyst SA-Ru-MoS2 has an overpotential of only 76 mV at 10 mA cm -2 in alkaline medium, and has an overpotential of 252 mV at 10 mA cm -2 in acidic medium. In addition, when testing its stability in alkaline medium, the prepared catalyst material has an initial current density of 10.64 mA cm -2 and decays to 6.49 mA cm -2 after 20 hours, and the decay amplitude is about 39%.

[0007] How to prepare a high-performance Ru single-atom catalyst using a more simplified method remains an urgent problem to be solved in this field. Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] Aiming at the problems existing in the prior art, one of the objectives of the present invention is to replace Pt with Ru at a lower cost to prepare a catalyst for electrocatalytic hydrogen production with comparable performance, so as to solve the problem of reducing the cost of the catalyst for electrocatalytic hydrogen production.

[0010] Another objective of the present invention is to solve the technical problems in the prior art that the noble metal Ru loading of the catalyst for electrocatalytic hydrogen production is large, but the dispersion degree of Ru atoms is low, and the aggregation is serious, and the catalytic efficiency of the noble metal cannot be fully exerted.

[0011] Another objective of the present invention is to solve the problem that when making an electrode from the catalyst material for electrocatalytic hydrogen production, a binder or adhesive is required, which not only increases the complexity of the manufacturing process, the labor cost and the manufacturing cost, but also reduces the catalyst efficiency.

[0012] Another objective of the present invention is to solve the technical problems in the prior art that the Ru-based single-atom catalyst cannot simultaneously have excellent catalytic activities in alkaline media, acidic media and seawater, as well as the technical problem of the stability of the catalyst.

[0013] Another objective of the present invention is to solve the problems in the prior art that the preparation method of the Ru-based single-atom catalyst is complex, and it takes multiple steps to obtain the Ru-based single-atom catalyst, with a large technical difficulty and a low controllability, which is not suitable for large-scale preparation of high-efficiency catalysts.

[0014] Solutions for Solving the Problems

[0015] The present invention relates to:

[0016] 1. A 1T-MoS2 supported Ru single-atom lattice catalyst, which comprises: a substrate, a metal 1T-MoS2 layer coated on the substrate, and a Ru single-atom lattice supported on the surface of the metal 1T-MoS2 layer. Among them, relative to 100 g of the 1T-MoS2 supported Ru single-atom lattice catalyst, the mass content of Mo atoms is 6.5-8.5 wt.%, and the mass content of Ru atoms is 0.04-0.11 wt.%.

[0017] 2. The 1T-MoS2 supported Ru single-atom lattice catalyst according to item 1, wherein the substrate is a hydrophilic carbon matrix.

[0018] 3. The Ru single-atom array catalyst supported on 1T-MoS2 according to item 2, wherein the hydrophilic carbon matrix is carbon fiber cloth or carbon fiber paper, and the fiber diameter constituting the carbon fiber cloth and the carbon fiber paper is less than 1 μm.

[0019] 4. The Ru single-atom array catalyst supported on 1T-MoS2 according to item 1, wherein, relative to 100 g of the Ru single-atom array catalyst supported on 1T-MoS2, the mass content of Mo atoms is 7.2 - 7.5 wt.%, and the mass content of Ru atoms is 0.06 - 0.10 wt.%.

[0020] 5. A method for preparing the Ru single-atom array catalyst supported on 1T-MoS2 according to any one of items 1 to 4, comprising the following steps:

[0021] S1: After alternately rinsing the substrate with deionized water and ethanol, it is dried in vacuum at 45 - 60 °C for later use;

[0022] S2: Dissolve sodium molybdate dihydrate, thiourea, and water-soluble polymer in deionized water to obtain a mixed solution;

[0023] S3: Place the treated substrate in a reaction kettle, and after putting the mixed solution into the reaction kettle, heat the reaction kettle to 160 - 200 °C and maintain it for 20 - 24 h to obtain a 1T-MoS2 precursor with a metal 1T-MoS2 layer coated on the substrate;

[0024] S4: After alternately washing the 1T-MoS2 precursor with ethanol and deionized water several times, it is placed in a blast drying oven at 45 °C - 60 °C and dried for 12 h;

[0025] S5: Immerse the 1T-MoS2 precursor in a 0.25 mM - 10.5 mM RuCl3 solution and let it stand for 0.5 - 5 h;

[0026] S6: After alternately washing the impregnated 1T-MoS2 precursor with ethanol and deionized water several times, it is dried in a blast drying oven at 45 °C - 60 °C for 5 h to obtain the Ru single-atom array catalyst supported on 1T-MoS2;

[0027] S7: Put the Ru single-atom array catalyst supported on 1T-MoS2 into a disposable sample tube and fill it with nitrogen for protection.

[0028] 6. The method for preparing the Ru single-atom array catalyst supported on 1T-MoS2 according to item 4, in S2, the mixed solution is stirred for 30 - 100 minutes and then left to stand for 30 - 100 minutes.

[0029] 7. The preparation method of the Ru single-atom dot catalyst supported on 1T-MoS2 according to Item 4, wherein in the S2, the water-soluble polymer is PEG-2000 to PEG-20000 with a viscosity value greater than 5.0 mPas but less than 35.0 mPas.

[0030] 7. An electrode, characterized in that it is made of the Ru single-atom dot catalyst supported on 1T-MoS2 according to any one of Items 1 to 4

[0031] Effects of the Invention

[0032] The present invention prepares a Ru single-atom dot catalyst supported on 1T-MoS2, which can be directly used as an electrode. The reaction conditions of its preparation method are mild, the reaction is stable, the requirements for equipment are low, the repeatability is good, and industrial production can be realized.

[0033] The reaction conditions of the present invention are mild: the reaction stability is 160 - 200 °C, and the reaction time is within 24 h; the requirements for equipment are low: an ordinary blast drying oven is the preparation equipment for this experiment; it is simple and low-cost: this experiment uses a one-step hydrothermal method plus a one-step impregnation method to prepare the Ru single-atom dot catalyst supported on 1T-MoS2 and the electrode, without more experimental limiting conditions. The Ru loading in the obtained catalyst and electrode is less than 0.11% wt., and its performance in electrocatalytic water splitting in 1.0 M KOH exceeds that of the Pt / C catalyst, greatly reducing the cost of the catalyst and having great commercial application value.

[0034] In addition, the Ru single-atom dot catalyst supported on 1T-MoS2 of the present invention has excellent catalytic performance not only in alkaline media but also in acidic media, and the overpotential in both media is lower than 100 mV. The Ru single-atom dot catalyst supported on 1T-MoS2 of the present invention can continuously and stably electrolyze natural seawater at a large current density of 150 mA cm 2 for 250 h at an overpotential of 600 mV without a decrease in activity and stability. Description of the Drawings

[0035] Figure 1 XRD patterns of 1T-MoS2 / CC, Ru 0.5 -1T-MoS2 / CC, Ru1-1T-MoS2 / CC, Ru3-1T-MoS2 / CC, Ru5-1T-MoS2 / CC obtained in Examples 1 to 5 of the present invention;

[0036] Figure 2 XRD patterns of 1T-MoS2 / CC, Ru 0.5Raman spectra of -1T-MoS2 / CC, Ru1-1T-MoS2 / CC, Ru3-1T-MoS2 / CC, and Ru5-1T-MoS2 / CC;

[0037] Figure 3 This is the aberration-corrected electron microscopy image (Ru1-1T-MoS2 / CC) and data processing results of Example 2 of the present invention (for 1 h).

[0038] Figure 4 This is the polarization curve of Example 2 of the present invention in 0.5 M H2SO4, 1.0 M KOH, and natural seawater (seawater from the Bohai Bay).

[0039] Figure 5 This is the I-T curve of Example 2 of the present invention when continuously electrolyzing seawater for 250 hours at a high current density of 150 mA cm 2 (overpotential of 600 mV). Detailed implementation manners

[0040] Loading noble metal Ru on metallic MoS2 can obtain the optimal hydrogen adsorption free energy, which is an important means to enhance the alkaline hydrogen evolution activity of the catalyst. However, noble metals have low abundance, small reserves, and high prices on Earth. Improving the efficiency of noble metal catalysts is an inevitable choice for developing supported noble metal catalysts. As an ideal type of catalyst, single atoms have the advantages of high atomic utilization efficiency, highly uniform active sites, ultra-high selectivity, and good stability and reusability. Therefore, uniformly dispersing single Ru atoms on the 1T-MoS2 support to form a single-atom catalyst can achieve high-performance alkaline hydrogen evolution while significantly reducing the amount of noble metal used, improving the utilization efficiency of noble metals, and reducing costs.

[0041] The in-plane of two-dimensional MoS2 is a S-Mo-S three-layer structure. The Mo atoms and S atoms in the plane are bonded by covalent bonds, and the single-layer MoS2 planes are connected by van der Waals forces. Depending on the coordination structure of sulfur atoms relative to the central Mo atom and the stacking order of single-layer MoS2, MoS2 exists in three different crystal structures, namely 1T, 2H, and 3R phases. 1T-MoS2 has a tetragonal structure, 2H-MoS2 is a hexagonal crystal system, and 3R-MoS2 is an orthorhombic crystal system. 2H-MoS2 and 3R-MoS2 naturally exist in molybdenite and can also be artificially synthesized.

[0042] 1T-MoS2 is a thermodynamic metastable state under ambient conditions and can only be artificially synthesized. 2H-MoS2 and 3R-MoS2 are semiconductors with poor conductivity. Their HER catalytic active sites come from the extremely limited edge sites, while the basal plane does not have catalytic activity. 1T-MoS2 is a metallic phase, and both its edge sites and basal plane sites have HER catalytic activity.

[0043] 1T-MoS2 itself has many lattice defects, and these defect sites provide excellent sites for anchoring single metal atoms. Moreover, the conductivity of 1T-MoS2 is several orders of magnitude higher than that of semiconductor-phase MoS2, making it an excellent substrate for single-atom catalysts. However, introducing single metal atoms into 1T-MoS2 easily leads to crystal distortion, S vacancies, and in-plane atomic plane sliding, thereby causing matrix phase transformation, resulting in reduced conductivity and fewer active sites on the substrate. Therefore, controlling the single-atom loading amount of the doping element to prevent 1T-MoS2 from undergoing phase transformation due to excessive accumulation of lattice distortion caused by excessive heteroatom loading and reducing the catalytic performance of the substrate is one of the technical difficulties to be solved for 1T-MoS2 as a single-atom catalyst substrate. In addition, preparing a noble metal single-atom lattice catalyst on a stable 1T-MoS2 substrate is crucial for maximizing the utilization rate of noble metals and obtaining a HER catalyst with a high concentration of active sites.

[0044] Through in-depth research, the inventor of the present invention prepared a Ru single-atom lattice catalyst supported on 1T-MoS2, which includes: a substrate, a 1T-MoS2 layer coated on the substrate, and a Ru single-atom lattice supported on the surface of the 1T-MoS2 layer.

[0045] The substrate is a hydrophilic carbon matrix, preferably carbon fiber cloth and carbon fiber paper. There is no particular limitation on the fiber diameter of the carbon fiber cloth and carbon fiber paper. Preferably, the diameter is 2 μm or less, more preferably 1 μm or less, particularly preferably 0.5 - 1 μm, and further preferably 0.8 - 1 μm. In the prior art, the Ru single-atom lattice uses MoS2 particles as the matrix and coats on its surface. However, in the process of large-scale production, due to the limitation of production equipment and harsh production environment on the dispersion degree of MoS2 particles, during the production process, the aggregation of MoS2 particles and the aggregation and uneven coating of Ru single atoms on MoS2 particles due to lattice distortion and the difference in the particle size of MoS2 particles occur. The present invention uses a hydrophilic carbon matrix with a fiber diameter of 0.5 - 1 μm as the matrix, which can not only make the prepared Ru single-atom lattice catalyst supported on 1T-MoS2 can be directly used as an electrode without other treatments such as adding adhesives or binders and coating on the required electrode matrix, etc.; moreover, using a hydrophilic carbon matrix with a fiber diameter of 0.5 - 1 μm can also more easily obtain a uniform 1T-MoS2 layer and can strongly support the 1T-MoS2 layer, making the 1T-MoS2 layer not easily undergo crystal distortion, S vacancies, and in-plane atomic plane sliding, thereby suppressing adverse effects such as matrix phase transformation, reduced conductivity, and fewer active sites on the substrate.

[0046] There is no particular limitation on the shape and size of the hydrophilic carbon matrix, which can be selected according to actual electrode needs.

[0047] In the 1T-MoS2 supported Ru single-atom lattice catalyst, relative to 100 g of the 1T-MoS2 supported Ru single-atom lattice catalyst, the mass content of Mo atoms is 6.0-9.0 wt.%, preferably 6.5-8.5 wt.%, more preferably 7.1-7.9 wt.%, and further preferably 7.2-7.5 wt.%. If the mass content of Mo atoms is too high, the 1T-MoS2 layer is too thick, and the unevenness on the surface of the hydrophilic carbon matrix will be covered by the 1T-MoS2 layer, reducing the exposed effective surface area. If the mass content of Mo atoms is too low, the 1T-MoS2 layer is too thin, and the 1T-MoS2 layer cannot be effectively attached, resulting in easy distortion of the crystal, easy sliding of S vacancies and intra-layer atomic planes, thereby reducing the stability of the 1T-MoS2 supported Ru single-atom lattice catalyst.

[0048] In the 1T-MoS2 supported Ru single-atom lattice catalyst, relative to 100 g of the 1T-MoS2 supported Ru single-atom lattice catalyst, the mass content of Ru atoms is 0.03-0.15 wt.%, preferably 0.04-0.11 wt.%, and more preferably 0.06-0.10 wt.%. If the mass content of Ru atoms is too high, the 1T-MoS2 layer will undergo a phase change due to excessive accumulation of lattice distortion caused by excessive loading of heteroatoms, leading to a decrease in the catalytic performance of the substrate. If the mass content of Ru atoms is too low, the catalytic performance will decrease.

[0049] Preparation method of 1T-MoS2 supported Ru single-atom lattice catalyst of the present invention, comprising the following steps: S1: After alternately rinsing the substrate with deionized water and ethanol, it is dried in vacuum at 45-60 °C for later use; S2: Dissolve sodium molybdate dihydrate, thiourea and water-soluble polymer in deionized water to obtain a mixed solution. Preferably, the mixed solution is stirred for 30-100 minutes and then left standing for 30-100 minutes to fully dissolve each component in the mixed solution. The water-soluble polymer is not particularly limited, and preferably PEG-2000-PEG-20000 with a viscosity value greater than 5.0 mPas but less than 35.0 mPas. Using PEG-2000-PEG-20000 with a viscosity value in this range can fully wet the surface of the carbon matrix and make the Mo ions deposit more uniformly on the surface of the carbon matrix; S3: Place the treated substrate in a reaction kettle, and after putting the mixed solution into the reaction kettle, heat the reaction kettle to 160-200 °C, preferably 180-190 °C, and keep it for 20-24 h, preferably 22 h, to obtain a 1T-MoS2 precursor with a metal 1T-MoS2 layer coated on the substrate; S4: After alternately washing the 1T-MoS2 precursor with ethanol and deionized water several times, it is placed in a blast drying oven at 45 °C-60 °C, preferably 50 °C, for drying. The drying time is not particularly limited. Considering from the perspective of economic cost, it is preferably 12 h; S5: Immerse the 1T-MoS2 precursor in a 0.25 mM-10.5 mM RuCl3 solution and let it stand for 0.5-5 h. The standing time is not particularly limited as long as the requirements are met; S6: After alternately washing the impregnated 1T-MoS2 precursor with ethanol and deionized water several times, it is dried in a blast drying oven at 45 °C-60 °C. The drying time is not particularly limited. Considering from the perspective of economic cost, it is preferably 5 h to obtain a 1T-MoS2 supported Ru single-atom lattice catalyst; S7: Put the 1T-MoS2 supported Ru single-atom lattice catalyst into a disposable sample tube and fill it with nitrogen for protection.

[0050] In step S3, the placement method of the treated substrate in the reaction kettle is not particularly limited as long as a uniform 1T-MoS2 coating can be obtained. Preferably, the treated substrate is bent into a V shape and vertically stands in the reaction kettle, so that the 1T-MoS2 precursor coating obtained is easy to adsorb Ru single atoms.

[0051] The prepared 1T-MoS2 supported Ru single-atom lattice catalyst can be directly used as an electrode, or made into an electrode together with other components.

[0052] The technical solution of the present invention will be further described and illustrated below through specific examples. The examples shown are only for illustrative purposes and do not limit the entire scope of the present invention.

[0053] Unless otherwise specified, the raw materials used in the embodiments of the present invention are all commonly used raw materials in the art. Among them, Na2MoO4·2H2O, CH4N2S, and PEG are all purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., and the purity grades are all analytical pure. The concentrated sulfuric acid and potassium hydroxide used as electrolytes are purchased from Sinopharm Chemical Reagent Co., Ltd., and the purity is analytical pure.

[0054] Example 1:

[0055] Take a 1 * 9.5 cm carbon cloth (HCP331N type carbon cloth produced by Suzhou Shengnuoke Technology Co., Ltd., with a fiber diameter of about 1 μm), rinse it alternately with deionized water and ethanol, and then dry it in a vacuum at 50 °C for later use; take 0.235 g of Na2MoO4·2H2O, 3.12 g of CH4N2S, and 0.1 g of PEG2000 (viscosity value between 12 and 16 mPas). Dissolve it in 60 mL of deionized water, let it stand for 100 minutes, and then stir magnetically for 30 minutes to obtain a mixed solution; after bending the treated carbon cloth into a V shape and standing it vertically in the reaction kettle, put the mixed solution into the reaction kettle and heat it to 180 °C, and maintain it within 24 h. After heating is completed, a 1T-MoS2 precursor supported on carbon cloth is obtained, denoted as 1T-MoS2 / CC precursor; wash the above 1T-MoS2 precursor alternately with ethanol and deionized water several times, and then dry it in a forced-air drying oven at 50 °C for 12 h for later use.

[0056] Then immerse the above 1T-MoS2 precursor in a 0.25 mM RuCl3 solution for 0.5 h, then wash the impregnated 1T-MoS2 precursor alternately with ethanol and deionized water several times, and then dry it in a forced-air drying oven at 60 °C for 5 h to obtain a 1T-MoS2 supported Ru single-atom lattice catalyst sample 1, denoted as Ru 0.5 -1T-MoS2 / CC, put the sample 1 into a disposable sample tube and fill it with nitrogen for protection.

[0057] Example 2

[0058] Except that the 1T-MoS2 precursor in Example 1 is immersed in a 0.25 mM RuCl3 solution for 0.5 h and changed to 1 h, prepare a 1T-MoS2 supported Ru single-atom lattice catalyst sample 2 in the same manner as Example 1, denoted as Ru1-1T-MoS2 / CC.

[0059] Example 3

[0060] Except that the 1T-MoS2 precursor in Example 1 was immersed in a 0.25 mM RuCl3 solution for 0.5 h and changed to 3 h, a 1T-MoS2 supported Ru single-atom lattice catalyst sample 3 was prepared in the same manner as in Example 1, denoted as Ru3-1T-MoS2 / CC.

[0061] Example 4

[0062] Except that the 1T-MoS2 precursor in Example 1 was immersed in a 0.25 mM RuCl3 solution for 0.5 h and changed to 5 h, a 1T-MoS2 supported Ru single-atom lattice catalyst sample 4 was prepared in the same manner as in Example 1, denoted as Ru5-1T-MoS2 / CC.

[0063] Example 5

[0064] Except that the standing time in Example 1 was changed to 50 minutes, the stirring time was changed to 60 minutes, and the hydrothermal reaction temperature was changed from 180 °C to 170 °C, a 1T-MoS2 supported Ru single-atom lattice catalyst sample 5 was prepared in the same manner as in Example 1.

[0065] Example 6:

[0066] Except that the magnetic stirring time in Example 1 was changed from 30 minutes to 100 minutes and the hydrothermal temperature was changed from 180 °C to 200 °C, a 1T-MoS2 supported Ru single-atom lattice catalyst sample 6 was prepared in the same manner as in Example 1.

[0067] Example 7

[0068] Except that the concentration of the RuCl3 solution in which the 1T-MoS2 precursor in Example 1 was immersed was changed from 0.25 mM to 3.5 mM, a 1T-MoS2 supported Ru single-atom lattice catalyst sample 7 was prepared in the same manner as in Example 1.

[0069] Example:

[0070] Except that the concentration of the RuCl3 solution in which the 1T-MoS2 precursor in Example 1 was immersed was changed from 0.25 mM to 4.7 mM, a 1T-MoS2 supported Ru single-atom lattice catalyst sample 8 was prepared in the same manner as in Example 1.

[0071] Example 9

[0072] Except that the concentration of the RuCl3 solution in which the 1T-MoS2 precursor in Example 1 was immersed was changed from 0.25 mM to 8.7 mM, a 1T-MoS2 supported Ru single-atom lattice catalyst sample 9 was prepared in the same manner as in Example 1.

[0073] Comparative Example 1

[0074] Except for changing 0.235 g of Na2MoO4·2H2O in Example 1 to 0.1 g of Na2MoO4, a 1T-MoS2-supported Ru single-atom lattice catalyst sample C1 was prepared in the same manner as in Example 1. Agglomeration of 1T-MoS2 nanosheets occurred in the precursor, which was not conducive to the subsequent loading of Ru single atoms.

[0075] Comparative Example 2

[0076] Except for changing 0.235 g of Na2MoO4·2H2O in Example 1 to 1.0 g of Na2MoO4, changing 3.12 g of CH4N2S to 1.4 g of CH4N2S, changing 0.1 g of PEG2000 to no addition of PEG2000, and changing 60 mL of deionized water to 80 mL of deionized water, a 1T-MoS2-supported Ru single-atom lattice catalyst sample C2 was prepared in the same manner as in Example 1. 2H-MoS2 with a mass fraction of about 20% appeared in the precursor, reducing the conductivity of the precursor.

[0077] It can be seen from Figure 1 that the first diffraction peak appears at about 9.3°, confirming that the MoS2 in the precursor is 1T-MoS2, rather than 2H-phase or 3R-phase MoS2. Figure 2 The Raman spectrum in -1 also confirms that the MoS2 layer in the 1T-MoS2-supported Ru single-atom lattice catalyst of the present invention is 1T-MoS2. The J1 Roman peak at 147 cm -1 is caused by the Mo-Mo stretching vibration in 1T-MoS2, and the J3 Roman peak at 335 cm Figure 1 and Figure 2 both confirm that the precursor is 1T-MoS2 supported on carbon cloth, and the well-dispersed 1T-MoS2 provides a high-quality substrate for the subsequent single-atom catalyst.

[0078] In the present invention, a highly dispersed noble metal single-atom lattice catalyst is prepared on an ultrathin 1T-MoS2 nanosheet precursor. As shown in Figure 3 a, it can be seen from the spherical aberration electron microscope image of the sample that individual Ru atoms are highly dispersed and arranged in a lattice pattern ( Figure 3 the boxed area in a). Within the field of view of the spherical aberration electron microscope image, there are multiple Ru single atoms arranged in a lattice pattern (indicated by arrows). The Ru single-atom lattice within the red box was further analyzed using the Digital Micrograph software of Gatan Company, USA. It can be seen that the Ru single atoms are highly dispersed, and the single Ru single-atom lattice is composed of 12 - 15 Ru single atoms.Figure 3 b), arranged in a linear pattern (dot matrix).

[0079] The Ru single-atom dot catalyst supported on 1T-MoS2 obtained in this invention was used as the cathode electrode, and the hydrogen evolution performance was tested on a Shanghai Chenhua CHI760E electrochemical workstation with a platinum wire as the counter electrode. The hydrogen evolution reaction occurred in a 0.5M H2SO4 electrolyte, and the overpotential to reach 10 mA cm 2 was 83 mV ( Figure 4 as shown by the five-pointed star legend in 2 ); the hydrogen evolution reaction occurred in 1M KOH, and the overpotential to reach 10 mA cm Figure 4 was 5 mV ( 2 as shown by the triangle legend in Figure 4 ); in the electrolysis of natural seawater (natural seawater in the Bohai Bay), the overpotential to reach 10 mA cm 2 was 390 mV ( Figure 5 as shown by the regular hexagon legend in 2 ); the catalyst prepared in this invention could stably electrolyze natural seawater at a large current density of 150 mA cm 2 for 250 h without a decrease in activity and stability at an overpotential of 600 mV ( 2 as shown). Generally, in the prior art, Pt / C is the commercial catalyst with the highest catalytic activity. When the hydrogen evolution reaction occurs in 0.5M H2SO4 electrolyte and 1M KOH electrolyte, the overpotential to reach 10 mA cm

[0080] The preparation method of the catalyst in this invention has few steps, is simple, the noble metal Ru loading is less than 0.11 wt%, Ru is in a dot matrix form, highly dispersed, low-cost and high-efficiency, with significant advantages. Its hydrogen evolution activity in acidic and alkaline media is better than that of the Pt / C catalyst, and it can directly electrolyze natural seawater with an extremely low overpotential, having outstanding commercial value.

[0081] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A 1T-MoS2 supported Ru single-atom array catalyst, comprising: A substrate, a metal 1T-MoS2 layer coated on the substrate, and Ru single-atom lattices supported on the surface of the metal 1T-MoS2 layer. Among them, relative to 100 g of the Ru single-atom lattice catalyst supported by 1T-MoS2, the mass content of Mo atoms is 6.5 - 8.5 wt.%, and the mass content of Ru atoms is 0.04 - 0.11 wt.%. The substrate is a hydrophilic carbon matrix, and the hydrophilic carbon matrix is carbon fiber cloth or carbon fiber paper. The fiber diameter constituting the carbon fiber cloth and the carbon fiber paper is less than 2 μm.

2. The Ru single-atom lattice catalyst supported by 1T-MoS2 according to claim 1. Relative to 100 g of the Ru single-atom lattice catalyst supported by 1T-MoS2, the mass content of Mo atoms is 7.2 - 7.5 wt.%, and the mass content of Ru atoms is 0.06 - 0.10 wt.%.

3. A preparation method of the Ru single-atom lattice catalyst supported by 1T-MoS2 according to any one of claims 1 - 2, comprising the following steps: S1: Alternately rinse the substrate with deionized water and ethanol, and then dry it in vacuum at 45 - 60 °C for later use; S2: Dissolve sodium molybdate dihydrate, thiourea, and a water-soluble polymer in deionized water to obtain a mixed solution; S3: Place the treated substrate in a reaction kettle, put the mixed solution into the reaction kettle, and then heat the reaction kettle to 160 - 200 °C and keep it for 20 - 24 h to obtain a 1T-MoS2 precursor with a metal 1T-MoS2 layer coated on the substrate; S4: Alternately wash the 1T-MoS2 precursor with ethanol and deionized water several times, and then dry it in a blast drying oven at 45 °C - 60 °C; S5: Immerse the 1T-MoS2 precursor in a 0.25 mM - 10.5 mM RuCl3 solution and let it stand for 0.5 - 5 h; S6: Alternately wash the impregnated 1T-MoS2 precursor with ethanol and deionized water several times, and then dry it in a blast drying oven at 45 °C - 60 °C for 5 h to obtain a Ru single-atom lattice catalyst supported by 1T-MoS2; S7: Put the Ru single-atom lattice catalyst supported by 1T-MoS2 into a disposable sample tube and fill it with nitrogen for protection; In S2, the water-soluble polymer is PEG-2000 - PEG-20000 with a viscosity value greater than 5.0 mPas but less than 35.0 mPas.

4. According to the preparation method of the Ru single-atom lattice catalyst supported by 1T-MoS2 in claim 3, in S2, stir the mixed solution for 30 - 100 minutes and then let it stand for 30 - 100 minutes.

5. An electrode, characterized in that Made from the Ru single-atom lattice catalyst supported by 1T-MoS2 according to any one of claims 1 - 2.

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