Process for the preparation of ruthenium catalysts and ruthenium catalysts

Abstract

The application provides a ruthenium catalyst preparation method and a ruthenium catalyst, relates to the technical field of catalyst preparation, and comprises the following steps: placing shielding reagents and a first solvent in a first beaker and stirring uniformly to obtain a first solution; placing a ruthenium-containing compound and a second solvent in a second beaker and stirring uniformly to obtain a second solution, wherein the molar ratio of the shielding reagents to the ruthenium atoms in the ruthenium-containing compound ranges from 5 to 100:1; placing alumina in a third beaker; mixing the first solution and the second solution and stirring uniformly to obtain a mixed solution; and adding the mixed solution into the third beaker and performing aging treatment to obtain the ruthenium catalyst. The catalyst preparation method provided by the application can prepare the ruthenium catalyst with the ruthenium distributed in the alumina by introducing the shielding reagents, so that the distribution area of the ruthenium in the alumina is increased, and the catalytic performance of the ruthenium catalyst is improved.

Description

Technical Field

[0001] This application relates to the field of catalyst preparation technology, and in particular to a method for preparing a ruthenium catalyst and the ruthenium catalyst itself. Background Technology

[0002] Bisphenol A is an important chemical raw material, widely used in the preparation of various polymer materials, such as polycarbonate and epoxy resin. However, bisphenol A is a toxic chemical, so it is replaced by hydrogenated bisphenol A. Hydrogenated bisphenol A is produced by the continuous hydrogenation reaction of bisphenol A. In this process, a catalyst corresponding to the hydrogenation reaction is used to improve the reaction rate.

[0003] In related technologies, the catalysts used in hydrogenation reactions can be supported noble metal catalysts, such as ruthenium catalysts with ruthenium as the active metal and alumina as the support.

[0004] However, due to the strong interaction between the active component and the support surface, the active metal mainly accumulates on the outer surface of the support. The structure of the ruthenium catalyst is an eggshell-shaped structure with a certain shell thickness. Therefore, the ruthenium catalyst in the related technology has the problem of narrow distribution range and small distribution area of ​​ruthenium in alumina. Summary of the Invention

[0005] This application provides a method for preparing a ruthenium catalyst and a ruthenium catalyst. The method can prepare a ruthenium catalyst in which ruthenium is distributed not only on the outer surface of alumina but also inside alumina, thereby increasing the distribution area of ​​ruthenium in alumina and improving the catalytic performance of the ruthenium catalyst.

[0006] To achieve the above objectives, this application adopts the following technical solution:

[0007] The first aspect of this application provides a method for preparing a ruthenium catalyst, comprising the following steps:

[0008] Step S01: Take the shielding reagent, place it in the first beaker, add the first solvent to the first beaker, and stir evenly to obtain the first solution;

[0009] Step S02: Take the ruthenium-containing compound, place it in the second beaker, add the second solvent to the second beaker, and stir until homogeneous to obtain the second solution;

[0010] The molar ratio of ruthenium atoms in shielding reagents and ruthenium-containing compounds ranges from (5-100):1;

[0011] Step S03: Take aluminum oxide and place it in the third beaker;

[0012] Step S04: Mix the first solution and the second solution and stir until homogeneous to obtain a mixed solution;

[0013] Step S05: The mixed solution is then added to the third beaker, and the solid-liquid mixture formed by the mixed solution and alumina in the third beaker is aged to obtain the ruthenium catalyst.

[0014] In some embodiments, in step S02, the molar ratio of the shielding reagent to the ruthenium atoms in the ruthenium-containing compound is in the range of (5-60):1.

[0015] In some embodiments, in step S02, the concentration of the ruthenium-containing compound in the second solution ranges from 0.005 mmol / L to 85 mmol / L.

[0016] In some embodiments, step S04 is carried out at a temperature range of 25-50°C, and the stirring time ranges from 0.5 to 2 hours.

[0017] In some embodiments, in step S05, the aging process is carried out at a temperature range of 20-50°C and the aging time ranges from 3 to 24 hours.

[0018] In some embodiments, the ruthenium catalyst is further subjected to drying treatment, wherein the drying treatment is carried out at a temperature range of 30-100°C and the drying treatment time ranges from 2 to 16 hours.

[0019] In some embodiments, in step S01, the shielding agent includes at least one of citric acid, tartaric acid, malic acid, acetic acid, and oxalic acid.

[0020] In some embodiments, in step S01, the pH value of the first solution is in the range of 1-3.

[0021] In some embodiments, in step S01, the first solvent includes at least one of deionized water, ethanol, and methanol; and / or,

[0022] In step S02, the second solvent includes at least one of deionized water, ethanol, and methanol.

[0023] In some embodiments, in step S02, the ruthenium-containing compound includes at least one of ruthenium trichloride hydrate and ruthenium nitrite.

[0024] In some embodiments, at least one of the following is included:

[0025] In steps S01, S02 and S04, the stirring method includes either magnetic stirring or mechanical stirring.

[0026] In step S04, the process of adding the mixed solution to the third beaker is carried out under ultrasonic treatment for a duration of 5-60 minutes.

[0027] The second aspect of this application provides a ruthenium catalyst, which is prepared by any of the above-described methods for preparing a ruthenium catalyst.

[0028] The ruthenium catalyst preparation method provided in this application includes the following steps: placing a shielding reagent and a first solvent in a first beaker and stirring evenly to obtain a first solution; placing a ruthenium-containing compound and a second solvent in a second beaker and stirring evenly to obtain a second solution, wherein the molar ratio of ruthenium atoms in the shielding reagent and the ruthenium-containing compound is in the range of (5-100):1; placing alumina in a third beaker; mixing the first solution and the second solution and stirring evenly to obtain a mixed solution; adding the mixed solution to the third beaker and aging it to obtain a ruthenium catalyst. This catalyst preparation method, by introducing a shielding reagent and controlling the molar ratio range of the shielding reagent and the ruthenium-containing compound, can prepare a ruthenium catalyst in which ruthenium is distributed not only on the outer surface of alumina but also inside alumina, thereby increasing the distribution area of ​​ruthenium in alumina and improving the catalytic performance of the ruthenium catalyst.

[0029] The ruthenium catalyst provided in this application has the same beneficial effects as the ruthenium catalyst preparation method provided in the above embodiments, and will not be repeated here.

[0030] In addition to the technical problems solved by the embodiments of this application, the technical features constituting the technical solutions, and the beneficial effects brought about by the technical features of these technical solutions described above, the ruthenium catalyst preparation method and other technical problems that the ruthenium catalyst can solve, other technical features included in the technical solutions, and the beneficial effects brought about by these technical features provided by the embodiments of this application will be further described in detail in the specific implementation. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic flowchart of a method for preparing a ruthenium catalyst provided in an embodiment of this application;

[0033] Figure 2 This is a cross-sectional structural diagram of alumina provided in an embodiment of this application.

[0034] Explanation of reference numerals in the attached figures:

[0035] R - The maximum distance from the outer contour of the alumina section to the center;

[0036] D - Maximum cross-sectional dimension of the alumina center. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0038] Bisphenol A is an important chemical raw material, widely used in the preparation of various polymer materials, such as polycarbonate and epoxy resin. However, bisphenol A is a toxic chemical, so it is replaced by hydrogenated bisphenol A. Hydrogenated bisphenol A is produced by the continuous hydrogenation reaction of bisphenol A. In this process, a catalyst corresponding to the hydrogenation reaction is used to improve the reaction rate.

[0039] In related technologies, the catalysts mentioned above can be supported noble metal catalysts, such as ruthenium catalysts with ruthenium as the active metal and alumina as the support. However, due to the strong adsorption between the active metal and the hydroxyl groups on the support, the active metal mainly accumulates on the outer surface of the support. Therefore, the structure of the ruthenium catalyst is an eggshell-shaped structure with a certain shell thickness, and the active metal ruthenium mainly accumulates on the outer surface of the alumina support, which has the problems of narrow distribution range and small distribution area.

[0040] To overcome the deficiencies in related technologies, this application provides a method for preparing a ruthenium catalyst. By introducing a shielding reagent, the hydroxyl groups on the surface of alumina are occupied or consumed, thereby weakening the adsorption force between ruthenium and the outer surface of alumina. As a result, ruthenium is distributed not only on the surface of alumina but also inside the alumina, thereby increasing the distribution area of ​​ruthenium in alumina and improving the catalytic performance of the ruthenium catalyst.

[0041] The contents of this application will now be described in detail with reference to the accompanying drawings, so that those skilled in the art can have a clearer and more detailed understanding of the contents of this application.

[0042] Example 1

[0043] Example 1 of this application provides a method for preparing a ruthenium catalyst, such as... Figure 1 As shown, it includes the following steps:

[0044] Step S01: Take the shielding reagent, place it in the first beaker, add the first solvent to the first beaker, and stir evenly to obtain the first solution;

[0045] Step S02: Take the ruthenium-containing compound, place it in the second beaker, add the second solvent to the second beaker, and stir until homogeneous to obtain the second solution;

[0046] The molar ratio of ruthenium atoms in shielding reagents and ruthenium-containing compounds ranges from (5-100):1;

[0047] Step S03: Take aluminum oxide and place it in the third beaker;

[0048] Step S04: Mix the first solution and the second solution and stir until homogeneous to obtain a mixed solution;

[0049] Step S05: The mixed solution is then added to the third beaker, and the solid-liquid mixture formed by the mixed solution and alumina in the third beaker is aged to obtain the ruthenium catalyst.

[0050] In some embodiments, the shape of the alumina used in the preparation of the ruthenium catalyst includes, but is not limited to, spherical, strip-shaped, clover-shaped, four-leaf-shaped, cylindrical, etc., for example, such as Figure 2 As shown, alumina with a clover-shaped cross section is used as the support for the ruthenium catalyst.

[0051] In some embodiments, in step S02, the molar ratio of the shielding reagent to the ruthenium atoms in the ruthenium-containing compound ranges from (5-100):1. For example, the molar ratio of the shielding reagent to the ruthenium-containing compound is 5:1, 10:1, 20:1, 30:1, 40:1, 60:1, 80:1, 100:1, etc.

[0052] In addition, this application also provides comparative examples, which differ from steps S01-S05 of the above embodiments only in that the comparative examples are examples of preparing ruthenium catalysts using a ruthenium catalyst preparation method involving unshielded reagents.

[0053] The ruthenium catalysts prepared in steps S01-S05 above and the ruthenium catalysts prepared in the comparative example were subjected to the following tests.

[0054] 1) Molar ratio of shielding reagent to ruthenium-containing compound (testing required only for examples)

[0055] Calculation formula:

[0056]

[0057] Where n is the amount of substance, in mol;

[0058] m - the mass of the substance, in grams;

[0059] M - The relative molecular mass of the substance, in g / mol.

[0060]

[0061] in, - The molar ratio of the shielding agent to the ruthenium-containing compound;

[0062] n1 - The number of moles of the shielding reagent, in mol;

[0063] The number of n2-ruthenium atoms, in mol;

[0064] The relative molecular mass of citric acid is 192.14 g / mol, that of tartaric acid is 150.1 g / mol, that of malic acid is 134.1 g / mol, that of oxalic acid is 90.035 g / mol, that of ruthenium trichloride contains 37-40% ruthenium atoms, and that of ruthenium nitrite contains 1.5% w / v ruthenium atoms.

[0065] 2) The thickness distribution of ruthenium atoms within alumina is compared to...

[0066] like Figure 2 As shown, the thickness distribution ratio of ruthenium atoms inside aluminum oxide is the ratio of the actual distribution thickness r of ruthenium atoms inside the aluminum oxide cross section to the maximum dimension R of the outer contour of the aluminum oxide cross section from the center.

[0067] Test method: The actual distribution thickness r of ruthenium atoms inside the alumina cross section and the maximum dimension R from the outer contour of the alumina cross section to the center were measured using an optical microscope.

[0068] Calculation formula:

[0069]

[0070] Among them, the thickness distribution ratio of β-ruthenium atoms inside aluminum oxide;

[0071] The maximum distance from the outer contour of the r-alumina section to the edge of the ruthenium metal layer, in μm;

[0072] R-Alumina cross-section outer contour to center maximum distance, μm.

[0073] 3) The distribution density of ruthenium atoms inside alumina is higher than that of ruthenium atoms.

[0074] like Figure 2 As shown, the distribution density ratio of ruthenium atoms inside aluminum oxide is the ratio of the number of ruthenium atoms at the endpoints to the number of ruthenium atoms at the center along the direction of the maximum cross-sectional dimension D passing through the center of the aluminum oxide.

[0075] Test method: The number of ruthenium atoms distributed along the D direction was obtained using a scanning electron microscope (SEM) equipped with an energy-dispersive X-ray spectrometer;

[0076] Calculation formula:

[0077]

[0078] Among them, the distribution density of φ-ruthenium atoms inside aluminum oxide;

[0079] N mid —The number of ruthenium atoms at the center point along direction D;

[0080] N0 — The number of ruthenium atoms at the endpoint along the D direction.

[0081] 4) Catalytic performance testing of ruthenium catalyst

[0082] In a fixed-bed miniaturized reactor, ruthenium catalyst is used to catalyze the continuous hydrogenation reaction of bisphenol A to prepare hydrogenated bisphenol A. The conversion rate is calculated based on the bisphenol A content in the reaction product. A high conversion rate of bisphenol A indicates high catalytic performance of the ruthenium catalyst, while a low conversion rate indicates low catalytic performance of the ruthenium catalyst.

[0083] The reaction conditions were as follows: temperature: 140℃, pressure: 6MPa, mass hourly space velocity: 2h. -1 Hydrogen flow rate: 60 mL / min, where mass hourly space velocity (MAV) is the ratio of the mass of fluid passing through the fixed-bed miniaturized reactor per unit time to the mass of the catalyst.

[0084] Test method: The concentration of bisphenol A in the raw materials and the concentration of bisphenol A in the reaction products were determined by gas chromatography.

[0085] The formula for calculating the bisphenol A conversion rate is:

[0086]

[0087] Among them, the conversion rate of η-bisphenol A;

[0088] x0—Bisphenol A content in the raw material;

[0089] x t —The content of bisphenol A in the reaction products.

[0090] By introducing a shielding agent during the preparation of the ruthenium catalyst, the hydroxyl groups on the outer surface of alumina are occupied or consumed, thereby reducing the interaction between ruthenium ions in the mixed solution and the hydroxyl groups on the outer surface of alumina. This allows ruthenium ions to not only exist on the outer surface of alumina, but also to penetrate into the interior of alumina under the influence of the concentration difference between the inside and outside of alumina, so that ruthenium can adhere to the interior of alumina. This increases the distribution area of ​​ruthenium in alumina and improves the catalytic performance of the ruthenium catalyst supported on alumina.

[0091] In other embodiments, in addition to mixing the first solution and the second solution evenly before adding them to the third beaker, the first solution and the second solution can also be added to the third beaker simultaneously to form a solid-liquid mixture with the alumina in the third beaker, thereby obtaining a ruthenium catalyst. For example, the method of mixing the first solution and the second solution evenly before adding them to the third beaker can make the alumina in the third beaker more uniformly contained in the mixed solution obtained by mixing the first solution and the second solution, which helps to obtain a ruthenium catalyst in which ruthenium is uniformly distributed in alumina.

[0092] In step S02, the molar ratio of the shielding reagent and the ruthenium-containing compound can be in the range of (5-60):1, so as to reduce the use of excess ruthenium compound, thereby reducing waste and lowering the cost of raw materials.

[0093] In step S02, the concentration of the ruthenium-containing compound in the second solution ranges from 0.005 mmol / L to 85 mmol / L. By controlling the concentration of the ruthenium-containing compound in the second solution, the reaction rate can be controlled, and excessive use of the ruthenium-containing compound can be avoided, thereby reducing material and processing costs.

[0094] Specifically, step S04 is carried out at a temperature range of 25-50℃, and the stirring time ranges from 0.5 to 2 hours.

[0095] In some embodiments, mixing the first solution and the second solution at a certain temperature helps to increase the mixing rate. For example, mixing the first solution and the second solution at a temperature range of 25-50°C and stirring at that temperature for 0.5-2 hours helps to mix the first solution and the second solution more quickly and thoroughly to obtain a more uniform mixed solution, thereby helping to distribute ruthenium in the mixed solution more evenly in the alumina.

[0096] In step S05, the aging process is carried out at a temperature range of 20-50℃ and the aging time ranges from 3 to 24 hours.

[0097] In some embodiments, the solid-liquid mixture formed by the mixed solution and the alumina in the third beaker is aged at a certain temperature, for example at 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, and 50°C. This facilitates the flow of the ruthenium compound, allowing it to enter the interior of the alumina under the influence of the concentration difference. This promotes the contact between the ruthenium compound and the alumina, so that the ruthenium is distributed inside the alumina. As a result, a ruthenium catalyst is obtained where the ruthenium is distributed not only on the outer surface of the alumina but also inside the alumina, increasing the distribution area of ​​ruthenium in the alumina and improving the catalytic performance of the ruthenium catalyst.

[0098] In some embodiments, the aging time is set according to the aging temperature. For example, the aging time ranges from 3 to 24 hours to ensure that the mixed solution is given sufficient aging time at different aging temperatures so that ruthenium in the mixed solution is fully loaded in the alumina, which helps to increase the distribution area of ​​ruthenium in the alumina and improve the catalytic performance of the ruthenium catalyst.

[0099] The method for preparing ruthenium catalyst also includes drying the ruthenium catalyst. The drying process is carried out at a temperature range of 30-100℃ and the drying time ranges from 2 to 16 hours.

[0100] In some embodiments, drying is required after the formation of the ruthenium catalyst to effectively remove residual mixed first and second solvents from the ruthenium catalyst. This prevents the ruthenium catalyst from having its catalytic performance affected by the solvents during storage, transportation, and use, resulting in higher stability. It also avoids the mixed solution from causing chemical reactions between the ruthenium catalyst and the reactants during catalytic operation, thus preventing the normal production of the target product and production efficiency from being affected.

[0101] In some embodiments, the drying process is carried out at a temperature range of 30-100°C and for a duration of 2-16 hours. Ruthenium catalysts require drying at relatively high temperatures, and a temperature range of 30-100°C is relatively easy to provide in the chemical industry. The matching drying time range of 2-16 hours provides a reasonable preparation time rhythm. Furthermore, in the process of preparing ruthenium catalysts by matching the drying temperature and drying time, the drying time of the ruthenium catalyst can be controlled by adjusting the drying temperature, thereby providing the possibility of controlling and shortening the preparation time of the ruthenium catalyst and improving the preparation efficiency of the ruthenium catalyst.

[0102] In some embodiments, in step S01, the shielding agent includes at least one of citric acid, tartaric acid, malic acid, oxalic acid, and acetic acid. Tartaric acid, malic acid, oxalic acid, and acetic acid have the same steps in the preparation of ruthenium catalyst, and can all increase the distribution area of ​​ruthenium in alumina and improve the catalytic performance of ruthenium catalyst. However, compared with citric acid, tartaric acid, oxalic acid, and malic acid, acetic acid, as a shielding agent, results in a smaller distribution thickness and smaller distribution area of ​​ruthenium inside alumina.

[0103] In step S01, the pH value of the first solution is in the range of 1-3. For example, the pH value of the first solution can be 1, 1.2, 1.5, 1.8, 2, 2.5, 3, etc. Adjusting the pH value of the first solution to 1-3 helps to reduce the mutual adsorption force between ruthenium ions in the mixed solution and the hydroxyl groups on the outer surface of alumina in step S05. This allows ruthenium to not only be loaded on the outer surface of alumina, but also to enter the interior of alumina under the action of concentration difference, so that ruthenium is distributed inside the alumina, thereby increasing the distribution area of ​​ruthenium in alumina and improving the catalytic performance of the ruthenium catalyst.

[0104] In some embodiments, in step S01, adding a first solvent to the first beaker can adjust and control the concentration of the shielding reagent in the first beaker. The first solvent includes at least one of deionized water, ethanol, and methanol. Therefore, the first solvent can be selected from deionized water, ethanol, or methanol. The first solvent can also be selected from a mixture of deionized water and ethanol, a mixture of deionized water and methanol, a mixture of ethanol and methanol, or a mixture of deionized water, ethanol, and methanol.

[0105] In some embodiments, in step S02, adding a second solvent to the second beaker can adjust and control the concentration of the ruthenium-containing compound in the second beaker. The second solvent includes at least one of deionized water, ethanol, and methanol. Therefore, the second solvent can be selected from deionized water, ethanol, or methanol. The second solvent can also be selected from a mixture of deionized water and ethanol, a mixture of deionized water and methanol, a mixture of ethanol and methanol, or a mixture of deionized water, ethanol, and methanol.

[0106] In some embodiments, the first solvent and the second solvent may each include at least one of deionized water, ethanol, and methanol. The first solvent and the second solvent may be of the same type or different types. When the first solvent and the second solvent are of the same type, the first solution and the second solution can have the same homogeneity and consistency, avoiding different concentration gradients in different solutions due to different solvents, which would lead to poor homogeneity during mixing. In addition, it can reduce the types of solvents purchased, reduce the cost of purchasing, storing and disposing of them, and improve economic efficiency.

[0107] In step S02, the ruthenium-containing compound includes at least one of hydrated ruthenium trichloride and nitrosyl ruthenium nitrate. The ruthenium-containing compound can be hydrated ruthenium trichloride or nitrosyl ruthenium nitrate, or it can be a mixture of hydrated ruthenium trichloride and nitrosyl ruthenium nitrate. Hydrated ruthenium trichloride and nitrosyl ruthenium nitrate have the same steps in the preparation of ruthenium catalyst, and have the same function and effect.

[0108] In some embodiments, in steps S01, S02 and S04, the stirring method includes magnetic stirring and mechanical stirring. The stirring method can be magnetic stirring or mechanical stirring, or a combination of magnetic stirring and mechanical stirring. By increasing the external stirring method, the time to obtain a uniform first solution, second solution and mixed solution can be shortened, and the time cost can be reduced.

[0109] In some embodiments, in step S04, the process of adding the mixed solution to the third beaker is carried out under ultrasonic treatment for a duration of 5-60 minutes. Ultrasonic waves can generate strong micro-stirring through acoustic cavitation, promoting the entry of ions into the alumina channels. This helps the shielding reagent in the mixed solution to be uniformly dispersed on the outer surface of the alumina, occupying or consuming the hydroxyl groups on the outer surface of the alumina, thereby reducing the adsorption force between ruthenium and the outer surface of the alumina. In addition, it helps the ruthenium compound to be uniformly dispersed on the outer surface and inside of the alumina, so that ruthenium is uniformly distributed in the alumina, thereby increasing the distribution area of ​​ruthenium in the alumina.

[0110] This application also provides a ruthenium catalyst, prepared by any of the above-described ruthenium catalyst preparation methods, including but not limited to applications in hydrogenation reactions, reactions of alcohol oxidation to aldehydes or ketones, olefin metathesis reactions, photocatalysis and electrocatalysis reactions, organic synthesis reactions, etc.

[0111] The following will further illustrate the method for preparing a ruthenium catalyst and the ruthenium catalyst provided by the present invention through specific embodiments and comparative examples, as shown in Table 1 and the conclusion.

[0112] It should be noted that, in order to avoid the influence of the different number of ruthenium atoms in the ruthenium-containing compounds in Examples 1-6 and Comparative Example 1 on the thickness distribution ratio and distribution density ratio of ruthenium atoms in the alumina inside the ruthenium catalyst prepared by the ruthenium catalyst preparation method, the mass of ruthenium in the ruthenium-containing compounds in Examples 1-6 and Comparative Example 1 was selected as 0.3% of the mass of alumina. The proportion of ruthenium mass to alumina mass selected here is a conventional choice in the ruthenium catalyst preparation process and will not be elaborated here. In addition, in the process of preparing the ruthenium catalyst by the ruthenium catalyst preparation method of this application, a quantitative amount of ruthenium atoms are attached to the alumina under the impetus of the concentration difference of the mixed solution.

[0113] Unless otherwise specified, the reagents, materials and instruments used in the following examples are all conventional reagents, materials and instruments in the art, and can be obtained commercially. The reagents, solvents, solutions, compounds and the like involved can also be synthesized by conventional methods in the art.

[0114] Table 1: Data Table of Examples and Comparative Examples

[0115]

[0116]

[0117] The following conclusions can be drawn from Table 1:

[0118] 1) The distribution area of ​​ruthenium atoms in alumina in the ruthenium catalyst is not directly related to the mass of the shielding reagent and the mass of the ruthenium-containing compound, but is directly related to the molar ratio of the shielding reagent to ruthenium atoms. Comparing Examples 1-6 and Comparative Example 1, it can be seen that the thickness distribution ratio of ruthenium atoms inside alumina in Examples 1-6 is greater than that in Comparative Example 1. This indicates that in the ruthenium catalyst prepared by the method of introducing the shielding reagent, ruthenium atoms can be distributed more deeply inside the alumina, and the distribution range and distribution area of ​​ruthenium atoms in alumina are wider. The distribution density ratio of ruthenium atoms inside alumina in Examples 1-6 is greater than that in Comparative Example 1. This indicates that ruthenium atoms are not only distributed on the surface of alumina, but more ruthenium atoms enter the interior of alumina, and the distribution of ruthenium atoms in alumina is more uniform. In addition, the conversion rate of bisphenol A in Examples 1-6 is greater than that in Comparative Example 1. This indicates that the ruthenium catalyst prepared by the method of introducing the shielding reagent has higher catalytic performance.

[0119] Therefore, we can conclude that the method of preparing ruthenium catalyst by introducing a shielding reagent can enable ruthenium to attach to the interior of alumina, thereby increasing the distribution area and uniformity of ruthenium in alumina, and thus improving the catalytic performance of ruthenium catalysts supported on alumina.

[0120] 2) As can be seen from Examples 1-3, when the molar ratio of the shielding reagent to ruthenium atoms in the ruthenium-containing compound is in the range of (5-30):1, as the molar ratio of the shielding reagent to ruthenium atoms increases, the thickness distribution ratio of ruthenium atoms inside the alumina increases, the distribution density ratio of ruthenium atoms inside the alumina increases, and the conversion rate of bisphenol A also increases. This indicates that as the molar ratio of the shielding reagent to ruthenium atoms increases, the ruthenium atoms are distributed deeper, wider, larger in area, and more uniformly in the alumina, resulting in stronger catalytic performance of the ruthenium catalyst. Furthermore, when the molar ratio of the shielding reagent to ruthenium atoms in the ruthenium-containing compound is 30:1, the thickness distribution ratio of ruthenium atoms inside the alumina is 1, meaning that ruthenium can be distributed at every position inside the alumina.

[0121] 3) As can be seen from Examples 3-6, when the molar ratio of the shielding reagent to ruthenium atoms in the ruthenium-containing compound is in the range of (30-100):1, the thickness distribution ratio of ruthenium atoms inside the alumina no longer changes with the change of the molar ratio of the shielding reagent to ruthenium atoms. Ruthenium can be distributed at every position inside the alumina, and the distribution density ratio of ruthenium atoms inside the alumina and the conversion rate of bisphenol A no longer change significantly. However, when the molar ratio of the shielding reagent to ruthenium atoms in the ruthenium-containing compound is 60:1, the distribution density ratio of ruthenium atoms inside the alumina and the conversion rate of bisphenol A both have maximum values. However, when the molar ratio of the shielding reagent to ruthenium atoms in the ruthenium-containing compound continues to increase, the conversion rate of bisphenol A no longer increases. This indicates that when the molar ratio of the shielding reagent to ruthenium atoms in the ruthenium-containing compound is 60:1, the ruthenium catalyst prepared by the method of introducing the shielding reagent has the strongest catalytic performance.

[0122] Therefore, it can be concluded that when the molar ratio of the shielding reagent to ruthenium atoms in the ruthenium-containing compound is in the range of (5-30):1, the catalytic performance of the ruthenium catalyst prepared by the ruthenium catalyst preparation method is enhanced with the increase of the molar ratio of the shielding reagent to ruthenium atoms in the ruthenium-containing compound. When the molar ratio of the shielding reagent to ruthenium atoms in the ruthenium-containing compound is in the range of (30-100):1, the catalytic performance of the ruthenium catalyst prepared by the ruthenium catalyst preparation method no longer changes significantly with the increase of the molar ratio of the shielding reagent to ruthenium atoms in the ruthenium-containing compound. However, when the molar ratio of the shielding reagent to ruthenium atoms in the ruthenium-containing compound is 60:1, the catalytic performance of the ruthenium catalyst is the strongest.

[0123] It should be noted that the terms "one embodiment," "embodiment," "exemplary embodiment," "some embodiments," etc., mentioned in the specification indicate that the described embodiment may include a specific feature, structure, or characteristic, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments, whether explicitly described or not, is within the knowledge scope of those skilled in the art.

[0124] Generally speaking, terms should be understood at least in part by their use in context. For example, at least in part by context, the term "one or more" as used in the text can be used to describe any feature, structure, or characteristic of the singular meaning, or a combination of features, structures, or characteristics of the plural meaning. Similarly, at least in part by context, terms such as "a" or "the" can also be understood to convey either singular or plural usage.

[0125] It should be readily understood that the terms “on,” “above,” and “on top of” in this application should be interpreted in the broadest possible sense, such that “on” means not only “directly on something” but also “on something” with an intermediate feature or layer therebetween, and that “above” or “on top of” means not only “on top of something” but also “on top of something” without an intermediate feature or layer therebetween (i.e., directly on something).

[0126] Furthermore, for ease of explanation, spatially relative terms such as "below," "below," "under," "above," "above," etc., may be used to describe the relationship of one element or feature relative to other elements or features as shown in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation other than those shown in the figures. The device may have other orientations (rotated 90° or in other orientations), and the spatially relative descriptive terms used herein may be interpreted accordingly.

[0127] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for preparing a ruthenium catalyst, characterized by, Includes the following steps: Step S01: Take the shielding reagent, place it in the first beaker, add the first solvent to the first beaker, and stir evenly to obtain the first solution; Step S02: Take the ruthenium-containing compound, place it in the second beaker, add the second solvent to the second beaker, and stir until homogeneous to obtain the second solution; The molar ratio of the shielding reagent to the ruthenium atoms in the ruthenium-containing compound is in the range of (5-100):1; Step S03: Take aluminum oxide and place it in the third beaker; Step S04: Mix the first solution and the second solution and stir until homogeneous to obtain a mixed solution; Step S05: Add the mixed solution to the third beaker and age the solid-liquid mixture formed by the mixed solution and the alumina in the third beaker to obtain the ruthenium catalyst.

2. The method for preparing a ruthenium catalyst according to claim 1, characterized in that, In step S02, the molar ratio of the shielding reagent to the ruthenium atoms in the ruthenium-containing compound is in the range of (5-60):

1.

3. The method for preparing a ruthenium catalyst according to claim 1, characterized in that, In step S02, the concentration of the ruthenium-containing compound in the second solution ranges from 0.005 mmol / L to 85 mmol / L.

4. The method for preparing a ruthenium catalyst according to claim 1, characterized in that, Step S04 is carried out at a temperature range of 25-50℃, and the stirring time ranges from 0.5 to 2 hours.

5. The method for preparing a ruthenium catalyst according to claim 1, characterized in that, In step S05, the aging process is carried out at a temperature range of 20-50℃ and the aging time ranges from 3 to 24 hours.

6. The method for preparing a ruthenium catalyst according to claim 1, characterized in that, The process also includes drying the ruthenium catalyst at a temperature range of 30-100°C for a duration of 2-16 hours.

7. The method for preparing a ruthenium catalyst according to claim 1, characterized in that, In step S01, the shielding agent includes at least one of citric acid, tartaric acid, malic acid, acetic acid, and oxalic acid.

8. The method for preparing a ruthenium catalyst according to claim 1, characterized in that, In step S01, the pH value of the first solution is in the range of 1-3.

9. The method for preparing a ruthenium catalyst according to claim 1, characterized in that, In step S01, the first solvent includes at least one of deionized water, ethanol, and methanol; and / or, In step S02, the second solvent includes at least one of deionized water, ethanol, and methanol.

10. A method for preparing a ruthenium catalyst according to claim 1, characterized in that, In step S02, the ruthenium-containing compound includes at least one of ruthenium trichloride hydrate and ruthenium nitrite.

11. The method for preparing a ruthenium catalyst according to claim 1, characterized in that, Includes at least one of the following: In steps S01, S02 and S04, the stirring method includes either magnetic stirring or mechanical stirring. In step S04, the process of adding the mixed solution to the third beaker is carried out under ultrasonic treatment for a duration of 5-60 minutes.

12. A ruthenium catalyst, characterized in that, It is prepared by any one of the ruthenium catalyst preparation methods according to claims 1-11.

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