Ruthenium-containing single atom catalysts, methods of making and using the same

Abstract

The application discloses a single-atom ruthenium-containing catalyst and a preparation method and application thereof. The single-atom ruthenium-containing catalyst comprises a carrier and an active ingredient, and the active ingredient is loaded on the carrier; and the active ingredient comprises single-atom ruthenium. The single-atom ruthenium-containing catalyst has high catalytic efficiency, low ruthenium loading rate, wide applicability, can efficiently treat various plastics, has high stability, and has a wide application prospect in the field of preparing aviation fuel by plastic hydrogenation.

Description

Technical Field

[0001] This application relates to the field of catalyst synthesis, specifically to a ruthenium-containing single-atom catalyst, its preparation method, and its application. Background Technology

[0002] The efficient recycling of plastic waste is crucial for environmental sustainability and the production of high-value fuels. Existing chemical recycling methods for plastic waste mainly include hydrolysis, pyrolysis, and liquid-phase hydrogenation, but these methods suffer from problems such as high energy consumption, complex processes, and poor product selectivity.

[0003] Hydrogenolysis can degrade plastics into short-chain hydrocarbons, but it typically requires high temperatures (>300℃) and high pressures (>3MPa), resulting in high energy consumption and poor product selectivity. Pyrolysis has been widely used for upgrading and recycling mixed plastic waste, but its products contain a large number of unsaturated oxygen-containing groups, which are prone to repolymerization, reducing fuel quality. Therefore, further hydrogenation refining is usually required. Liquid-phase hydrogenation can improve fuel quality, but it requires additional cooling and heating steps, increasing process complexity and limiting industrial application. Existing technologies for hydrogenating polystyrene plastics to produce aviation fuel also have many problems, such as high energy consumption, complex processes, and the need for high temperature and high pressure conditions (>200℃, above 2MPa), increasing equipment investment and operating costs. Low catalyst activity and large amounts of precious metals are also present; conventional Ru / C or Ru / Al2O3 catalysts require up to 5wt% Ru loading, resulting in low catalytic efficiency and poor economic efficiency. Furthermore, most existing hydrogenolysis and liquid-phase hydrogenation methods are designed for single plastic types, while the sources of actual plastic waste are complex, affecting industrial applications.

[0004] Therefore, further research is needed on ruthenium-containing catalysts. Summary of the Invention

[0005] This application aims to at least partially address one of the technical problems existing in the prior art. To this end, this application provides a ruthenium-containing single-atom catalyst, its preparation method, and its application. In this ruthenium-containing catalyst, the ruthenium active component is supported on a support in the form of single atoms. This ruthenium-containing catalyst has high catalytic efficiency, low ruthenium loading rate, wide applicability, can efficiently process various plastics, and has high stability, showing broad application prospects in the field of hydrogenation of plastics to produce aviation fuel.

[0006] In a first aspect, this application proposes a ruthenium-containing catalyst comprising a support and an active component, wherein the active component is supported on the support; the active component comprises ruthenium in single-atom form. Thus, the ruthenium active component is dispersed on the support in single-atom form, with each ruthenium atom participating in the catalytic reaction as an independent active site, maximizing the exposure of active sites and improving catalytic efficiency.

[0007] According to embodiments of this application, the carrier comprises cobalt oxide and aluminum oxide.

[0008] According to an embodiment of this application, the molar ratio of cobalt to aluminum in the carrier is (1-3):1.

[0009] According to embodiments of this application, the loading of the active ingredient is 0.05 to 0.1 wt% based on the total mass of the ruthenium-containing catalyst.

[0010] In a second aspect of this application, a method for preparing the above-mentioned ruthenium-containing catalyst is proposed, comprising: mixing a cobalt source, an aluminum source, and water to obtain a first solution; mixing a ruthenium source, an alkaline substance, and water to obtain a second solution; mixing the first solution and the second solution to collect a precipitate; and heating the precipitate to obtain the ruthenium-containing catalyst.

[0011] According to embodiments of this application, the cobalt source includes at least one of cobalt nitrate hexahydrate, cobalt chloride, and cobalt acetate, the aluminum source includes aluminum nitrate nonahydrate, and the ruthenium source includes ruthenium chloride trihydrate.

[0012] According to an embodiment of this application, the molar ratio of cobalt source to aluminum source in the first solution is (1-3):1.

[0013] According to an embodiment of this application, the concentration of the cobalt source in the first solution is 0.5 to 1 mmol / mL.

[0014] According to an embodiment of this application, the concentration of the ruthenium source in the second solution is 0.5 to 1 mg / mL.

[0015] According to an embodiment of this application, the concentration of the alkaline substance in the second solution is 1 to 2 mmol / mL.

[0016] According to an embodiment of this application, the volume ratio of the first solution to the second solution is 1:(0.5 to 1.5).

[0017] According to an embodiment of this application, the pH is maintained at 8-9 during the mixing process.

[0018] According to an embodiment of this application, before the heat treatment, the precipitate is washed and dried, and the washing agent used in the washing treatment includes water and ethanol.

[0019] According to an embodiment of this application, the drying temperature is 70–90°C.

[0020] According to an embodiment of this application, the heat treatment is carried out in a 2-8% hydrogen / argon mixed atmosphere.

[0021] According to an embodiment of this application, the temperature of the heat treatment is 300-500°C, and the time is 1-3 hours.

[0022] In a third aspect of this application, the application of the aforementioned ruthenium-containing catalyst in plastic degradation is proposed.

[0023] According to embodiments of this application, the ruthenium-containing catalyst is used in the preparation of fuel oil through the hydrolysis of plastics.

[0024] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0025] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0026] Figure 1 This is an image of the RuSA / Co2Al catalyst in Test Example 1 of this application under a high-angle annular dark-field scanning transmission electron microscope;

[0027] Figure 2 This is the XAFS R-space data plot of the RuSA / Co2Al catalyst in Test Example 2 of this application;

[0028] Figure 3 This is an atomic structure model of a Ru single atom in the RuSA / Co2Al catalyst in Test Example 2 of this application;

[0029] Figure 4 This is a schematic diagram of the reaction process in Embodiment 2 of this application;

[0030] Figure 5 This is a graph showing the yield and conversion of aviation fuel and aromatic hydrocarbons from the pyrolysis and hydrogenolysis of polystyrene plastic using different catalysts in Example 2 of this application.

[0031] Figure 6 The chromatograms of the polystyrene pyrolysis products produced by the RuSA / Co2Al catalyst and the RuNP / Co2Al catalyst in Test Example 3 of this application are shown.

[0032] Figure 7 In-situ infrared spectra of the liquid products after plastic hydrogenation experiments using RuSA / Co2Al catalyst and RuNP / Co2Al catalyst in Test Example 4 of this application;

[0033] Figure 8 This is a diagram showing the catalytic effect of the RuSA / Co2Al catalyst on the conversion of real plastics to jet fuel in Example 3 of this application;

[0034] Figure 9This is a distribution diagram of the catalytic products of the RuSA / Co2Al catalyst for different mixed plastics in Example 3 of this application;

[0035] Figure 10 This is a graph showing the long-term stability test results of the RuSA / Co2Al catalyst in Test Example 5 of this application;

[0036] Figure 11 This is a graph showing the combustion performance of aviation fuel prepared using the RuSA / Co2Al catalyst in Test Example 5 of this application. Detailed Implementation

[0037] The embodiments of this application are described in detail below. The embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0038] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Furthermore, in the description of this application, unless otherwise stated, "multiple" means two or more.

[0039] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0040] In this document, the terms “comprising” or “including” are open-ended expressions, meaning that they include the contents specified in this application but do not exclude other contents.

[0041] In this document, the terms “optionally,” “optionally,” or “optionally” generally refer to an event or condition that may, but may not, occur, and the description includes both cases in which the event or condition occurs and cases in which the event or condition does not occur.

[0042] Terms and Definitions

[0043] In this paper, the term "RuSA / Co2Al" refers to a catalyst in which ruthenium in single-atom form is supported on a support comprising cobalt oxide and aluminum oxide, wherein the molar ratio of cobalt to aluminum in the support is 2:1.

[0044] In this paper, the term "RuNP / Co2Al" refers to a catalyst in which ruthenium nanoparticles are supported on a support comprising cobalt oxide and aluminum oxide, wherein the molar ratio of cobalt to aluminum in the support is 2:1.

[0045] In this article, the term "PS" stands for polystyrene.

[0046] In this article, the term "PE" refers to polyethylene.

[0047] In this article, the term "PP" refers to polypropylene.

[0048] Ruthenium-containing catalysts

[0049] In a first aspect, this application proposes a ruthenium-containing catalyst comprising a support and an active component, wherein the active component is supported on the support; the active component comprises ruthenium in single-atom form. Thus, the ruthenium active component is dispersed on the support in single-atom form, with each ruthenium atom participating in the catalytic reaction as an independent active site, maximizing the exposure of active sites and improving catalytic efficiency.

[0050] According to embodiments of this application, the support comprises cobalt(II) oxide and aluminum(II) oxide. This effectively loads the active ingredients, optimizes the electronic structure and reactive sites of the catalyst, and improves the overall performance of the catalyst.

[0051] According to embodiments of this application, the molar ratio of cobalt to aluminum in the support is (1-3):1. For example, it can be 1:1, 2:1, 3:1, etc. This further optimizes the electronic structure and reactive sites of the catalyst, thereby improving the catalyst's activity and selectivity.

[0052] According to embodiments of this application, the loading of the active ingredient is 0.05–0.1 wt%. For example, it can be 0.05 wt%, 0.06 wt%, 0.07 wt%, 0.08 wt%, 0.09 wt%, or 0.1 wt%. Thus, ruthenium is loaded onto the support in the form of single atoms, achieving high catalytic efficiency with a low loading rate, maximizing the utilization of active sites, reducing costs, and improving catalytic efficiency.

[0053] method

[0054] In a second aspect of this application, a method for preparing the aforementioned ruthenium-containing catalyst is proposed, comprising: mixing a cobalt source, an aluminum source, and water to obtain a first solution; mixing a ruthenium source, an alkaline substance, and water to obtain a second solution; mixing the first solution and the second solution to collect a precipitate; and heating the precipitate to obtain the ruthenium-containing catalyst. Thus, the reaction can be carried out under ambient pressure of 0.1 MPa, allowing the active component, the ruthenium source, to be uniformly dispersed on the support in single-atom form, thereby maximizing the utilization of active sites and improving catalytic efficiency.

[0055] According to embodiments of this application, the cobalt source includes at least one of cobalt nitrate hexahydrate, cobalt chloride, and cobalt acetate; the aluminum source includes aluminum nitrate nonahydrate; and the ruthenium source includes ruthenium chloride trihydrate. Thus, through extensive experimental screening, the selection of cobalt, aluminum, and ruthenium sources ensures uniform dispersion and high loading efficiency of the active components in the catalyst, while also optimizing the electronic structure and reactive sites of the catalyst.

[0056] According to embodiments of this application, the molar ratio of cobalt source to aluminum source in the first solution is (1-3):1. For example, it can be 1:1, 2:1, or 3:1. This optimizes the composition and performance of the support, allowing the active ingredients to be uniformly dispersed on the support, thereby improving the activity and stability of the catalyst.

[0057] According to embodiments of this application, the concentration of the cobalt source in the first solution is 0.5–1 mmol / mL. For example, it can be 0.5 mmol / mL, 0.6 mmol / mL, 0.7 mmol / mL, 0.8 mmol / mL, 0.9 mmol / mL, or 1 mmol / mL. This optimizes the composition and performance of the support, allowing the active ingredient to be uniformly dispersed on the support, thereby improving the activity and stability of the catalyst.

[0058] According to embodiments of this application, the concentration of the ruthenium source in the second solution is 0.5–1 mg / mL. For example, it can be 0.5 mg / mL, 0.6 mg / mL, 0.7 mg / mL, 0.8 mg / mL, 0.9 mg / mL, or 1 mg / mL. This optimizes the composition and performance of the support, allowing the active ingredient to be uniformly dispersed on the support, thereby improving the activity and stability of the catalyst.

[0059] According to embodiments of this application, the concentration of the alkaline substance in the second solution is 1–2 mmol / mL. For example, it can be 1 mmol / mL, 1.1 mmol / mL, 1.2 mmol / mL, 1.3 mmol / mL, 1.4 mmol / mL, 1.5 mmol / mL, 1.6 mmol / mL, 1.7 mmol / mL, 1.8 mmol / mL, 1.9 mmol / mL, or 2 mmol / mL. According to some specific embodiments of this application, the alkaline substance includes sodium hydroxide. This facilitates the dissolution of the ruthenium source, forming a homogeneous mixture.

[0060] According to embodiments of this application, the volume ratio of the first solution to the second solution is 1:(0.5 to 1.5). For example, it can be 1:0.5, 1:1, or 1:1.5. This ensures that the ruthenium and the support meet an optimal ratio, thereby improving the activity and stability of the catalyst.

[0061] According to embodiments of this application, the pH is maintained at 8-9 during the mixing process. For example, it can be pH 8, pH 8.5, or pH 9. According to some specific embodiments of this application, the mixing process includes a co-precipitation titration process, in which the first and second solutions are added dropwise to water while maintaining the pH at 8.5, and the mixture is stirred at room temperature for 16 hours to obtain a precipitate. This improves the activity and stability of the catalyst.

[0062] According to an embodiment of this application, before the heat treatment, the precipitate is washed and dried. The washing agent used includes water and ethanol. This removes residual unreacted metal salts, impurities, and solvents from the precipitate.

[0063] According to embodiments of this application, the drying temperature is 70–90°C. For example, it can be 70°C, 71°C, 72°C, 73°C, 74°C, 75°C, 76°C, 77°C, 78°C, 79°C, 80°C, 85°C, or 90°C. This removes moisture and residual solvent from the precipitate.

[0064] According to an embodiment of this application, the heat treatment is carried out in a 2-8% hydrogen / argon mixed atmosphere. This allows a reduction reaction to occur, reducing the active ingredient ruthenium to its metallic state.

[0065] According to embodiments of this application, the heat treatment temperature is 300–500°C, and the time is 1–3 hours. This promotes the full reduction and uniform dispersion of the active ingredient on the support, thereby forming a ruthenium-containing catalyst with high activity and stability.

[0066] use

[0067] In a third aspect, this application discloses the application of the aforementioned ruthenium-containing catalyst in the degradation of plastics. Therefore, the ruthenium-containing catalyst of this application has broad applicability and can efficiently treat a variety of plastics.

[0068] According to embodiments of this application, the ruthenium-containing catalyst is used in the hydrogenolysis of plastics to produce fuel oil. Therefore, the ruthenium-containing catalyst of this application exhibits high stability and efficient processing capabilities in the hydrogenolysis of plastics to produce fuel oil.

[0069] According to embodiments of this application, the plastic includes polystyrene, polyethylene, and polypropylene.

[0070] The following will explain the solution of this application with reference to embodiments. Those skilled in the art will understand that the following embodiments are for illustrative purposes only and should not be considered as limiting the scope of this application. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in the art or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0071] Example 1

[0072] Weigh 4.1384 g (14.22 mmol) of cobalt nitrate (Co(NO3)2·6H2O) and 2.6672 g (7.11 mmol) of aluminum nitrate (Al(NO3)3·9H2O), dissolve them in 20 mL of deionized water, and sonicate for 10 min to obtain the first solution.

[0073] In another beaker, take 50 μL of RuCl3·3H2O solution with a mass concentration of 20 mg / mL, add 1.366 g of NaOH, and add deionized water to make up to 19.9 mL to form a second solution.

[0074] Under vigorous stirring, the first and second solutions were added dropwise to 40 mL of deionized water, while maintaining the pH of the solution at 8.5 ± 0.2. The dropping rate was adjusted to ensure the formation of a uniform precipitate.

[0075] Continue stirring for 16 hours to promote the formation of Co2Al layered double hydroxide (LDH) and to ensure that Ru is uniformly dispersed in the precursor material.

[0076] The solid product was separated by centrifugation (8000 rpm, 10 min) and washed twice with deionized water and ethanol to remove unreacted metal salts and residual solvent.

[0077] The sample was vacuum dried at 80°C for 12 hours and then ground into a fine powder.

[0078] The obtained powder was reduced at 400℃ for 2 hours under a 5% H2 / Ar atmosphere with a heating rate of 5℃ / min to finally obtain the RuSA / Co2Al catalyst.

[0079] Comparative Example 1

[0080] The difference from Example 1 is that the RuCl3·3H2O solution is replaced with anhydrous RuCl3 solution.

[0081] The RuNP / Co2Al catalyst was prepared.

[0082] Comparative Example 2

[0083] The difference from Example 1 is that the RuCl3·3H2O solution was replaced with an equal volume of deionized water.

[0084] Co2Al support was prepared.

[0085] Test Example 1

[0086] High-resolution transmission electron microscopy (HR-TEM) was used to examine the RuSA / Co2Al catalyst prepared in Example 1. It was observed that Ru single atoms were uniformly dispersed on the Co2Al support, without the formation of clusters or nanoparticles. The results are shown in the figure below. Figure 1 As shown.

[0087] Test Example 2

[0088] X-ray absorption fine structure (XAFS) was used to analyze the RuSA / Co2Al catalyst prepared in Example 1 and the RuNP / Co2Al catalyst prepared in Comparative Example 1, while RuO2, Ru foil, and RuCl3 were also detected. The results are as follows: Figure 2 As shown, the RuSA / Co2Al catalyst prepared in Example 1 exhibits Ru in Ru-O and Ru-Co coordination structures, with no direct Ru-Ru bonds, demonstrating its single-atom dispersion characteristics. Its atomic structure model is shown in the figure below. Figure 3 As shown; however, in the RuNP / Co2Al catalyst prepared in Comparative Example 1, Ru atoms exist in a Ru-Ru coordination structure rather than being supported on the support in the form of single atoms.

[0089] Example 2

[0090] 1. In this example, the RuSA / Co2Al catalyst prepared in Example 1 was used to conduct a plastic hydrogenation experiment in a fixed-bed reactor.

[0091] The test procedure is as follows Figure 4As shown, a micro dual-stage fixed-bed reactor is used, with the upstream stage used for hydrogen pyrolysis and the downstream stage used for vapor-phase hydrogenation.

[0092] Step 1 (Hydrogen Pyrolysis): Reaction temperature: 460℃; Carrier gas: H2, 50mL / min; Reaction pressure: 0.15MPa; Feed: Polystyrene (PS), 50mg per batch.

[0093] Step 2 (gas-phase hydrogenation): Reaction temperature: 160℃; Catalyst loading: 25mg RuSA / Co2Al (catalyst to PS mass ratio 5:1); Hydrogen flow rate: 80mL / min.

[0094] 2. The difference from the above process is that the RuNP / Co2Al catalyst prepared in Comparative Example 1 and the Co2Al support prepared in Comparative Example 2 were used in the fixed bed reactor to carry out plastic hydrogenation experiments, with the blank group as a control.

[0095] The results are as follows Figure 5 As shown, compared with the RuNP / Co2Al catalyst prepared in Comparative Example 1 and the Co2Al support prepared in Comparative Example 2, the RuNP / Co2Al catalyst prepared in Example 1 can efficiently catalyze the hydrogenation reaction of plastics, with a yield of 94.8 wt%.

[0096] Test Example 3

[0097] The liquid products of the RuSA / Co2Al catalyst prepared in Example 1 of Example 2 and the liquid products of the RuNP / Co2Al catalyst prepared in Comparative Example 1 of Example 2 after undergoing plastic hydrogenation experiments were analyzed by GC-MS. The results are as follows: Figure 6 As shown, the liquid products after RuSA / Co2Al catalysis are mainly cycloalkanes, while the liquid products after RuNP / Co2Al catalysis still contain aromatic hydrocarbons, indicating incomplete hydrogenolysis.

[0098] Test Example 4

[0099] In-situ infrared spectroscopy analysis was performed on the liquid products of the RuSA / Co2Al catalyst prepared in Example 1 of Example 2 after undergoing plastic hydrogenation experiments, and on the liquid products of the RuNP / Co2Al catalyst prepared in Comparative Example 1 after undergoing plastic hydrogenation experiments. The results are as follows: Figure 7 As shown, RuSA / Co2Al can rapidly eliminate the C=C vibration peak of the benzene ring (1591 cm⁻¹). -1 The hydrogenation rate is faster than that of the RuNP / Co2Al catalyst.

[0100] Example 3

[0101] Using the method described in Example 2, catalytic hydrogenation experiments were conducted on different mixed plastics using a RuSA / Co2Al catalyst, including foam packaging, disposable cups, food packaging, and discarded toys. The main component of these mixed plastics was polystyrene, and the composition is shown in Table 1. The results are as follows: Figure 8 As shown, the RuSA / Co2Al catalyst can be applied to the catalytic hydrogenation of various mixed plastics, and has broad industrial application prospects. The catalytic product distribution diagram is shown below. Figure 9 As shown, the RuSA / Co2Al catalyst can catalyze the hydrogenation of plastics to produce aviation fuel.

[0102] Table 1

[0103]

[0104] Test Example 5

[0105] This test example aims to test the long-term stability of the RuSA / Co2Al catalyst prepared in Example 1. The specific steps are as follows:

[0106] In a continuous fixed-bed reactor, PS pyrolysis oil was used as feedstock, and a RuSA / Co2Al catalyst was used for a continuous hydrogenation reaction at 180℃ and 0.5MPa for 110 h. The results are as follows: Figure 10 As shown, the catalyst activity remained stable and still exhibited high catalytic activity after 110 hours of reaction.

[0107] Test Example 6

[0108] This test case aims to test the combustion performance of the fuel obtained from the plastic hydrogenation experiment in Example 2. The results are as follows: Figure 11 As shown,

[0109] A constant-volume combustion chamber was used to evaluate the combustion performance of plastic oil prepared by catalytic hydrogenation. The maximum temperature of the combustion chamber was raised to 900 K, and the maximum ambient back pressure was set to 6 MPa to simulate the top dead center state of an engine. A single-orifice injector with a nozzle diameter of 0.12 mm was installed at the top of the combustion chamber for fuel injection. An ICCD camera with a 310+10 nm bandpass filter was used to measure the flame lift-off length (LOL), while a high-speed camera was used to record the ignition delay time and flame evolution process. The results are as follows: Figure 11 As shown, this demonstrates the high purity of the fuel prepared in this application and the application of the ruthenium-containing catalyst in the preparation of fuel from plastic hydrogenolysis.

[0110] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0111] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A ruthenium-containing catalyst, characterized in that, The ruthenium-containing catalyst includes a support and an active component, wherein the active component is supported on the support; The active ingredient includes ruthenium in single-atom form.

2. The ruthenium-containing catalyst according to claim 1, characterized in that, The carrier comprises cobalt oxide and aluminum oxide.

3. The ruthenium-containing catalyst according to claim 2, characterized in that, The molar ratio of cobalt to aluminum in the carrier is (1-3):

1.

4. The ruthenium-containing catalyst according to claim 1, characterized in that, Based on the total mass of the ruthenium-containing catalyst, the loading of the active ingredient is 0.05–0.1 wt%.

5. A method for preparing the ruthenium-containing catalyst according to any one of claims 1 to 4, characterized in that, include: The cobalt source, aluminum source, and water are mixed to obtain the first solution; A second solution is obtained by mixing a ruthenium source, an alkaline substance, and water. The first solution and the second solution are mixed, and the precipitate is collected. The precipitate was heated to obtain the ruthenium-containing catalyst.

6. The method according to claim 5, characterized in that, The cobalt source includes at least one of cobalt nitrate hexahydrate, cobalt chloride, and cobalt acetate; the aluminum source includes aluminum nitrate nonahydrate; and the ruthenium source includes ruthenium chloride trihydrate.

7. The method according to claim 5, characterized in that, The molar ratio of cobalt source to aluminum source in the first solution is (1-3):1; Optionally, the concentration of the cobalt source in the first solution is 0.5 to 1 mmol / mL.

8. The method according to claim 5, characterized in that, The concentration of the ruthenium source in the second solution is 0.5–1 mg / mL; Optionally, the concentration of the alkaline substance in the second solution is 1–2 mmol / mL; Optionally, the volume ratio of the first solution to the second solution is 1:(0.5 to 1.5); Optionally, during the mixing process, the pH is maintained at 8-9.

9. The method according to claim 5, characterized in that, Before the heat treatment, the precipitate is washed and dried, and the washing agent used includes water and ethanol. Optionally, the drying temperature is 70–90°C; Optionally, the heat treatment is carried out in a 2-8% hydrogen / argon mixed atmosphere; Optionally, the heat treatment is performed at a temperature of 300–500°C for a duration of 1–3 hours.

10. The use of the ruthenium-containing catalyst according to any one of claims 1 to 4 in the degradation of plastics; Preferably, the ruthenium-containing catalyst is used in the hydrogenolysis of plastics to produce fuel oil.

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