A ruthenium-based catalyst for ammonia synthesis, its preparation method and application

Abstract

This invention discloses a ruthenium-based catalyst for ammonia synthesis, its preparation method, and its application, belonging to the field of ammonia synthesis catalyst technology. This invention uses barium titanate and at least one of rare earth metal hydrides and rare earth metal oxides, along with metal oxides, as raw materials for the ruthenium-based catalyst composite support. This ruthenium-based catalyst using a composite metal salt as the composite support exhibits excellent catalytic activity. During the preparation of the composite support, the metal hydride forms a barium salt-hydrogen bond-metal oxide and / or rare earth metal oxide synergistic composite metal salt with barium titanate, metal oxides, and / or rare earth metal oxides. The Ba salt and hydride in the support enhance the electron-donating capacity of the composite metal support. The metal oxides and / or rare earth metal oxides formed in solution and the subsequently added electron-donating agents ensure that the support has a sufficiently large specific surface area, increases the electron density on the support surface, and further enhances the electron-donating capacity of the composite support. This allows the final composite support to achieve high ammonia net value under low-pressure conditions with only a small amount of active noble metal Ru required for loading.

Description

Technical Field

[0001] This invention belongs to the field of ammonia synthesis catalyst technology, and particularly relates to a ruthenium-based catalyst for ammonia synthesis, its preparation method and application. Background Technology

[0002] Ammonia synthesis (NH3) is a fundamental chemical in modern chemical industry, widely used in agriculture, energy, and chemical industries. Developing green ammonia synthesis has become a key measure to promote energy transition and ensure energy security. Traditional ammonia synthesis processes, using the Haber-Bosch method, rely on high temperatures (300-500℃) and high pressures (10-30MPa), making them unsuitable for the intermittent and fluctuating nature of renewable energy generation such as wind and solar power. Therefore, developing catalysts capable of efficiently synthesizing ammonia under low-temperature and low-pressure conditions, enabling more flexible production capacity, smaller equipment, and greater operational flexibility, has become a research hotspot.

[0003] Ruthenium (Ru)-based ammonia synthesis catalysts are hailed as second-generation ammonia synthesis catalysts. In 1992, BP and Kellogg collaborated to develop a Ru / C (ruthenium-carbon) ammonia synthesis catalyst supported on graphitized activated carbon. This catalyst exhibited extremely high activity and could operate under pressures far lower than those of the traditional Haber-Bosch process. However, the carbon in the support undergoes methanation under the self-effects of the ruthenium catalyst, resulting in a limited lifespan.

[0004] Furthermore, ruthenium resources are limited, and catalyst costs must be considered in industrial production applications. Existing research reports that the ruthenium content in ruthenium-based catalysts is typically 3-8% by mass, which greatly limits the application and promotion of ruthenium-based ammonia synthesis catalysts. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes a ruthenium (Ru)-based catalyst for ammonia synthesis, its preparation method, and its application. The Ru-based catalyst of this invention can synthesize ammonia under mild conditions (temperature 300-450℃, pressure 3-8MPa) with a relatively low ruthenium loading, exhibiting high catalytic activity and stability for ammonia synthesis, which is beneficial for the large-scale promotion and application of low-pressure ammonia synthesis technology.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] This invention provides a ruthenium-based catalyst for ammonia synthesis, comprising a composite support and an active component, wherein the active component is supported on the composite support;

[0008] The raw materials for the composite carrier include at least one of metal hydrides and rare earth metal oxides, as well as barium titanate.

[0009] The active component is ruthenium;

[0010] The ruthenium in the ruthenium-based catalyst accounts for 0.5-2% by mass.

[0011] The principle of this invention: This invention uses barium titanate, rare earth hydrides, rare earth oxides and alkali metal oxides to prepare a composite support, which reduces the adsorption energy of hydrogen on the catalyst surface and at the same time reduces the activation energy of N2, thereby achieving efficient ammonia synthesis.

[0012] Furthermore, the metal hydride is an alkali metal hydride or an alkaline earth metal hydride;

[0013] And / or, the rare earth metal oxide is an oxide of a rare earth element.

[0014] Furthermore, the metal hydride is selected from sodium hydride, potassium hydride, magnesium hydride, calcium hydride, or titanium hydride; these hydrides are all ionic compounds and are easily thermally decomposed.

[0015] And / or, the rare earth metal oxide is selected from cerium oxide, gadolinium oxide, yttrium oxide, cesium oxide or rubidium oxide; these rare earth metals are highly reactive, readily form hydrides, and the hydrides have good stability and strong electron-donating ability.

[0016] Furthermore, the raw materials for the ruthenium-based catalyst used in ammonia synthesis also include electronic additives.

[0017] Furthermore, the electronic aid is a strong acid-weak base salt of an alkali metal and / or alkaline earth metal. As an example, the electronic aid is selected from potassium acetate, sodium acetate, calcium acetate, potassium chloride, sodium chloride, calcium chloride, potassium nitrate, sodium nitrate, or calcium nitrate. The above electronic aids can provide electrons to Ru, enhance the electron density on the Ru surface, and promote the adsorption and dissociation of N2.

[0018] This invention also provides a method for preparing the above-mentioned ruthenium-based catalyst for ammonia synthesis. When no electronic additives are present, the method includes the following steps: mixing at least one of a metal hydride and a rare earth metal oxide with barium titanate, calcining for the first time, dispersing the mixture in a mixed solution of ethanol and water after cooling, separating the solid and liquid after standing, and drying the filter residue under vacuum to obtain a composite support; mixing tetrahydrofuran and ruthenium salt, stirring, and adding the composite support; after the solution becomes completely transparent, rotary evaporating until the solution is dry; and calcining the obtained powder for the second time to obtain a composite support loaded with active metal ruthenium, which is the ruthenium-based catalyst for ammonia synthesis.

[0019] When containing electronic additives, the process includes the following steps: mixing at least one of a metal hydride and a rare earth metal oxide with barium titanate, performing a first calcination, cooling, and dispersing the mixture in a mixed solution of a polar solvent and water, allowing it to stand, separating the solid and liquid phases, and vacuum drying the filter residue to obtain a composite support; mixing the composite support with a methanol solution containing electronic additives, rotary evaporating until the solution is dry, and vacuum drying the resulting powder to obtain a composite support containing electronic additives; mixing tetrahydrofuran and ruthenium salt, stirring, and adding the composite support containing electronic additives, and after the solution becomes completely transparent, rotary evaporating until the solution is dry, and calcining the resulting powder to obtain a composite support loaded with active metal ruthenium, which is the ruthenium-based catalyst used for ammonia synthesis.

[0020] Furthermore, the molar ratio of the rare earth metal oxide, metal hydride, and barium titanate is (0.1-1):(1-6):(0-1). The change in the above raw material ratio will affect the ratio of rare earth metal oxide to rare earth metal hydride in the final composite carrier. When the proportion of rare earth metal hydride is too low, the electron density on the surface of the composite carrier is low, the electron-donating ability is weak, and it cannot effectively promote the adsorption and dissociation of N2; when it is too high, the electron-donating ability is too strong, and hydrogen poisoning is easy to occur.

[0021] And / or, the temperature of the first calcination is 400-800℃, and the time of the first calcination is 5-168h; preferably, the temperature of the first calcination is 610℃, and the time of the first calcination is 144h. The temperature and the reaction time will affect the ratio of rare earth metal oxides to rare earth metal hydrides in the final composite carrier.

[0022] And / or, the polar solvent is selected from one of methanol, ethanol, butanol, ethylene glycol, N,N-dimethylformamide (DMF), tetrahydrofuran, and acetone;

[0023] And / or, the second calcination temperature is 120-150℃, and the second calcination time is 3-5h.

[0024] The present invention also provides a method for forming the above-mentioned ruthenium-based catalyst, comprising the following steps: mixing a first binder, a second binder, a solid lubricant, an acid, a liquid lubricant and the ruthenium-based catalyst evenly, and then sequentially compressing, drying and calcining to obtain the formed ruthenium-based catalyst.

[0025] In the molding method of the ruthenium-based catalyst, the mass ratio of the first binder, the second binder, the liquid lubricant and the ruthenium-based catalyst is 1:(0-1):(0.1-20):(4-20), wherein the amount of the second binder added is not 0.

[0026] The present invention also provides the application of a ruthenium-based catalyst or a shaped ruthenium-based catalyst obtained by the above-described molding method in the synthesis of ammonia.

[0027] When ammonia is synthesized using the above-mentioned ruthenium-based catalyst or a shaped ruthenium-based catalyst, the reaction pressure is ≤10MPa, more preferably 3-8MPa, and exemplary is 5MPa or 8MPa.

[0028] Compared with the prior art, the present invention has the following advantages and technical effects:

[0029] 1. The ruthenium-based catalyst for ammonia synthesis provided by this invention can synthesize ammonia under low pressure (pressure ≤10MPa). This invention uses barium titanate and at least one of metal hydride and metal oxide as raw materials for the ruthenium-based catalyst composite support. The ruthenium-based catalyst with this composite metal salt as the composite support has excellent catalytic activity. In the preparation process of the composite support, the metal hydride forms a composite metal salt with barium titanate, metal oxide and / or metal oxide synergistic effect of barium salt-hydrogen bond-metal oxide and / or metal oxide. The Ba salt and hydride in the support enhance the electron-donating ability of the composite metal support. The metal oxide and / or oxide formed in the solution and the subsequently added electron auxiliary agent can ensure that the support has a sufficiently large specific surface area, increase the electron density of the support surface, and further enhance the electron-donating ability of the composite support. This allows the final composite support to achieve high ammonia net value under low pressure conditions with only a small amount of active noble metal Ru loading.

[0030] 2. By limiting the composition and formation conditions of the composite support, this invention improves the electron-donating ability and stability of the composite support, thereby enhancing the catalytic activity and stability of the ruthenium-based catalyst used for ammonia synthesis.

[0031] 3. This invention, by determining the influence of the selection and dosage of binders and lubricants during the molding process on the mechanical strength and ammonia synthesis catalytic performance of the catalyst, constructs catalyst particles of different shapes such as spherical, columnar, and plate-like. The resulting catalyst particles have high strength, with compressive strength generally greater than 100 N / cm². 2 It exhibits excellent catalytic performance in the ammonia synthesis reaction, at a space velocity of 10000 h⁻¹. -1 Under the conditions of a reaction pressure of 5 MPa, the outlet ammonia concentration is ≥13%; at a space velocity of 10000 h⁻¹ -1 Under the given conditions, when the reaction pressure is 8 MPa, the outlet ammonia concentration is ≥18%. Attached Figure Description

[0032] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0033] Figure 1This is a flowchart of the method for preparing the ruthenium-based catalyst for ammonia synthesis according to the present invention;

[0034] Figure 2 This is a schematic diagram of the connection of the instrument for concentration testing to evaluate the catalyst performance of the present invention.

[0035] Figure 3 This is a photograph of the 4mm spherical catalyst particles obtained in step (2) of Example 2 of the present invention.

[0036] Figure 4 This is a physical image of the 3mm cylindrical catalyst particles obtained in step (4) of Example 1 of the present invention. Detailed Implementation

[0037] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0038] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0039] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0040] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0041] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0042] An embodiment of the present invention provides a ruthenium-based catalyst for ammonia synthesis, comprising a composite support and an active component, wherein the active component is supported on the composite support;

[0043] The raw materials for the composite carrier include at least one metal hydride and a rare earth metal oxide, as well as barium titanate.

[0044] The active component is ruthenium;

[0045] Ruthenium accounts for 0.5-2% of the mass of ruthenium-based catalysts.

[0046] In embodiments of the present invention, the metal hydride is an alkali metal hydride or an alkaline earth metal hydride; the rare earth metal oxide is an oxide of a rare earth element.

[0047] In embodiments of the present invention, the metal hydride is selected from sodium hydride (NaH), potassium hydride (KH), magnesium hydride (MgH2), calcium hydride (CaH2), or titanium hydride (TiH2), preferably CaH2; the rare earth metal oxide is selected from cerium oxide (CeO2), gadolinium oxide (Gd2O3), yttrium oxide (Y2O3), cesium oxide (Cs2O), or rubidium oxide (Rb2O), preferably Gd2O3.

[0048] In embodiments of the present invention, the raw materials for the ruthenium-based catalyst used in ammonia synthesis also include electronic additives.

[0049] In embodiments of the present invention, the electronic additive is a strong acid-weak base salt of an alkali metal and / or an alkaline earth metal. As an example, the electronic additive is selected from potassium acetate, sodium acetate, calcium acetate, potassium chloride, sodium chloride, calcium chloride, potassium nitrate, sodium nitrate, or calcium nitrate.

[0050] Embodiments of the present invention also provide a method for preparing the above-described ruthenium-based catalyst for ammonia synthesis, the flowchart of which is shown below. Figure 1 As shown, when no electronic additives are present, the process includes the following steps: mixing at least one of a metal hydride and a rare earth metal oxide with barium titanate, calcining for the first time, dispersing the mixture in a mixed solution of ethanol and water after cooling, separating the solid and liquid after standing, and drying the filter residue under vacuum to obtain a composite support; mixing tetrahydrofuran and ruthenium salt, stirring and adding the composite support, and rotary evaporating the solution until it becomes completely transparent, and then calcining the resulting powder to obtain a composite support loaded with active metal ruthenium, which is a ruthenium-based catalyst for ammonia synthesis;

[0051] When containing electronic additives, the process includes the following steps: mixing at least one of a metal hydride and a rare earth metal oxide with barium titanate, performing a first calcination, cooling, and dispersing the mixture in a mixed solution of a polar solvent and water, allowing it to stand, separating the solid and liquid phases, and vacuum drying the filter residue to obtain a composite support; mixing the composite support with a methanol solution containing electronic additives, rotary evaporating until the solution is dry, and vacuum drying the resulting powder to obtain a composite support containing electronic additives; mixing tetrahydrofuran and ruthenium salt, stirring, adding the composite support containing electronic additives, and rotary evaporating until the solution becomes completely transparent, and then performing a second calcination to obtain a composite support loaded with active metal ruthenium, which is a ruthenium-based catalyst for ammonia synthesis.

[0052] During the first calcination process of this invention, the metal hydride decomposes to produce hydrogen, and the rare earth metal oxide reacts to become hydrides that are uniformly distributed on the surface of the composite metal salt. After the product of the first calcination is cooled, it is dispersed in a mixed solution of ethanol and water. It is then allowed to stand at room temperature to allow the metal element formed after decomposition and the unreacted metal hydride to oxidize and hydrolyze, followed by solid-liquid separation.

[0053] In embodiments of the present invention, the time for the solution to become completely transparent is generally 0.5-168 hours.

[0054] In embodiments of the present invention, the settling time is 0.1-24 hours, preferably 1-6 hours; the present invention does not limit the specific method of solid-liquid separation, for example, the separation method of solid-liquid separation can be conventional solvent removal methods such as filtration, centrifugation, and rotary evaporation.

[0055] In embodiments of the present invention, the ruthenium salt is selected from one of ruthenium trichloride, ruthenium nitrate, ruthenium acetylacetonate, and ruthenium dodecylcarbonyl, preferably ruthenium dodecylcarbonyl.

[0056] In an embodiment of the present invention, the first calcination is carried out under vacuum or a protective atmosphere, wherein the vacuum condition is ≤10. -1 Pa; the protective atmosphere is selected from inert gas atmospheres such as nitrogen and argon; preferably, the first calcination is carried out under vacuum conditions, with a vacuum degree ≤10. - 2 Pa.

[0057] In embodiments of the present invention, the molar ratio of rare earth metal oxide, metal hydride and barium titanate is (0.1-1):(1-6):(0-1), for example 1:2:0, 0.5:3:0.5, 1:3:0.1, 1:3.5:0.1 or 0.1:3:1;

[0058] The first calcination temperature is 400-800℃, and the first calcination time is 5-168h; preferably, the first calcination temperature is 580-650℃, and the first calcination time is 24-168h; more preferably, the first calcination temperature is 610℃, and the first calcination time is 144h.

[0059] The polar solvent is selected from methanol, ethanol, butanol, ethylene glycol, N,N-dimethylformamide (DMF), tetrahydrofuran, and acetone, preferably methanol or ethanol;

[0060] The second calcination temperature is 120-150℃, the second calcination time is 3-5h, and the heating rate is 0.1-10℃ / min; preferably, the second calcination temperature is 120℃ and the second calcination time is 3h.

[0061] In an embodiment of the present invention, the vacuum degree during vacuum drying is 10. -1 -10 -5 Between Pa.

[0062] In embodiments of the present invention, the volume ratio of polar solvent to water is (0.1-50):1, for example: 50:1, 20:1, 10:1, 1:1, etc.

[0063] An embodiment of the present invention also provides a method for forming the above-mentioned ruthenium-based catalyst, comprising the following steps: mixing a first binder, a second binder, a solid lubricant, an acid, a liquid lubricant and the ruthenium-based catalyst evenly, and then sequentially compressing, drying and calcining to obtain the formed ruthenium-based catalyst.

[0064] In the embodiment of the molding method for the ruthenium-based catalyst, the mass ratio of the first binder, the second binder, the liquid lubricant, and the ruthenium-based catalyst is 1:(0-1):(0.1-20):(4-20), wherein the amount of the second binder added is not zero; for example, it is 1:(0-1):1:5, 1:(0-1):2:8, 1:(0-1):3:10, 1:(0-1):3:15, and the amount of the second binder added is not zero in any of these cases.

[0065] In the embodiment of the ruthenium-based catalyst molding method, the first binder is boehmite, and the second binder is bentonite. This invention simultaneously incorporates two binders, as well as solid and liquid lubricants, to enhance the strength and increase the porosity of the molded particles.

[0066] In the embodiment of the ruthenium-based catalyst molding method, the solid lubricant is selected from molybdenum disulfide, graphite, graphene, talc, guar gum powder, and dry starch; the acid is selected from formic acid, acetic acid, hydrochloric acid, and citric acid; the liquid lubricant is selected from pure water or an aqueous solution of a metal hydroxide / salt, wherein the concentration of the aqueous solution of the metal hydroxide / salt is 0.001 mg / mL - saturation concentration; wherein the metal hydroxide / salt is selected from sodium hydroxide, potassium hydroxide, magnesium hydroxide, sodium nitrate, potassium nitrate, magnesium nitrate, sodium chloride, potassium chloride, calcium chloride, and magnesium chloride.

[0067] In the embodiment of the ruthenium-based catalyst forming method, the amount of solid lubricant added is 0.1-10% of the mass of the ruthenium-based catalyst; the amount of acid added is 0.1-5% of the mass of the ruthenium-based catalyst.

[0068] In the embodiment of the molding method for ruthenium-based catalysts, the molding method for ruthenium-based catalysts is compression molding. The shape of the ruthenium-based catalyst can be adjusted according to actual needs, for example, it can be columnar, sheet-like or spherical.

[0069] In the embodiment of the ruthenium-based catalyst forming method, the drying temperature is 20-80℃, the drying condition is vacuum, and the vacuum degree is 10. -1 -10 -5 The drying time is between 0.5 and 24 hours.

[0070] In the embodiment of the ruthenium-based catalyst forming method, the calcination temperature is 150-450℃, the calcination condition is vacuum, and the vacuum degree is 10. -1 -10 -5 The roasting time is between 0.5 and 24 hours.

[0071] The specific surface area of ​​the ruthenium-based catalyst formed in this invention is 30-100 m². 2 / g, for example, 35m 2 / g、40m 2 / g, 50m 2 / g、60m 2 / g、80m 2 / g or 100m 2 / g.

[0072] The ruthenium-based catalyst of this invention has a size of 1-5 mm, for example, 1 mm, 2 mm, 3 mm, 4 mm, or 5 mm.

[0073] The compressive strength of the ruthenium-based catalyst formed by the present invention is ≥60 N / cm, for example not less than 65 N / cm, preferably 70-200 N / cm, and exemplary values ​​are 75.8 N / cm, 88.9 N / cm, 93.5 N / cm, 135.9 N / cm, 167.3 N / cm, and 198.4 N / cm.

[0074] According to the American ASTM standard method, the wear rate of the ruthenium-based catalyst formed by this invention is ≤1%, for example, 0.2%, 0.5%, 0.7%, or 0.9%.

[0075] The present invention also provides the application of a ruthenium-based catalyst or a shaped ruthenium-based catalyst obtained by the above-described molding method in the synthesis of ammonia.

[0076] The synthesis of ammonia using the ruthenium-based catalyst or shaped ruthenium-based catalyst of the present invention is carried out in a low-pressure and mild environment. The reaction pressure is ≤10MPa, for example, 3-8MPa, with 3MPa, 5MPa, and 8MPa as examples; the reaction temperature is ≤450℃, for example, 300-450℃, with 300℃, 400℃, and 420℃ as examples.

[0077] Unless otherwise specified, room temperature and ambient temperature in this invention are both taken as 25±2℃.

[0078] All raw materials used in the embodiments of this invention were obtained through commercial purchase.

[0079] It should be noted that any aspects not described in detail in this invention are conventional practices in the field and are not the focus of this invention.

[0080] The technical solution of the present invention will be further illustrated by the following embodiments.

[0081] Example 1

[0082] This embodiment provides a method for preparing a Ru-based catalyst for ammonia synthesis, the steps of which are as follows:

[0083] (1) Take 29.078g (0.1247mol) BaTiO3, 31.5g (0.748mol) CaH2 and 45.20g (0.1247mol) Gd2O3 respectively, mix them evenly, and heat them at 10 -3 The powder was calcined at 610℃ for 144 hours under vacuum of 0.1 Pa. After cooling, it was uniformly dispersed in a mixed solution of ethanol and water (volume ratio of ethanol to water is 50:1), with the ratio of powder to mixed solution being 50 g / L. After stirring at room temperature for 3 hours, the powder was filtered. The filter residue was dried at 60℃ for 8 hours under vacuum of 0.1 Pa to obtain composite carrier powder.

[0084] (2) Add 2 L of tetrahydrofuran and 2.131 g of dodecacarbonyltriruthenium to a flask, stir with a magnetic stir bar for 10 min, add 50 g of the composite carrier powder obtained in step (1), impregnate at 30 °C until the solution becomes completely transparent, then rotary evaporate at 60 °C until the solution is dry, and collect the powder in 10 -3 The composite carrier powder loaded with active metal ruthenium was obtained by calcination at 120℃ (heating rate of 8℃ / min) for 3 hours.

[0085] (3) Take 100g of the composite carrier powder loaded with active metal ruthenium obtained in step (2) and mix it with 17g of boehmite, 2g of bentonite, 3g of graphene, 30g of deionized water and 3g of acetic acid. After stirring evenly, place it in a ZP-9A rotary tablet press with a pressure of 25kN and use a cylindrical mold with a diameter of 3mm to obtain 3mm cylindrical catalyst particles.

[0086] (4) Place the 3mm cylindrical catalyst particles obtained in step (3) in a vacuum drying oven and dry them at 10°C. -1 After drying at 30℃ for 6 hours, the sample was placed in a tube furnace and evacuated to 10℃. -2 Under a vacuum of 10 Pa, the temperature was increased to 60°C at a heating rate of 5°C / min and held for 3 hours. Then, the temperature was increased to 400°C at a heating rate of 2°C / min and held for 3 hours for calcination. This yielded 3 mm cylindrical ruthenium-based catalyst particles for ammonia synthesis (in this example, the proportion of ruthenium nanoparticles in the catalyst is approximately 1.3 wt%, i.e., the ruthenium loading in the ruthenium-based catalyst in this example is 1.3 wt%). A photograph of the actual product can be found in [image missing]. Figure 4 .

[0087] Example 2

[0088] This embodiment provides a method for preparing a Ru-based catalyst for ammonia synthesis, the steps of which are as follows:

[0089] (1) Take 100g of the composite carrier powder loaded with active metal ruthenium in step (2) of Example 1 and mix it with 17g of boehmite, 2g of bentonite, 3g of graphene, 30g of deionized water and 3g of acetic acid. After stirring evenly, place it in a ZP-9A rotary tableting machine with a pressure of 25kN and use a spherical mold with a diameter of 4mm to obtain 4mm spherical catalyst particles.

[0090] (2) Place the 4 mm spherical catalyst particles obtained in step (1) in a vacuum drying oven and dry them at 10 °C. -1 After drying at 30℃ for 6 hours, the sample was placed in a tube furnace and evacuated to 10℃. -2 Under a vacuum of 10 Pa, the temperature was increased to 60°C at a heating rate of 5°C / min and held for 3 hours. Then, the temperature was increased to 400°C at a heating rate of 2°C / min and held for 3 hours for calcination. This yielded 4 mm spherical ruthenium-based catalyst particles for ammonia synthesis (the ruthenium loading in this example is 1.3 wt%). A photograph of the actual particle is shown below. Figure 3 .

[0091] Example 3

[0092] The method for preparing the Ru-based catalyst for ammonia synthesis provided in this embodiment includes the following steps:

[0093] (1) Take 29.078g (0.1247mol) BaTiO3, 37.32g (0.748mol) TiH2 and 45.20g (0.1247mol) Gd2O3 respectively, mix them evenly, and heat them at 10 -3 The powder was calcined at 610℃ for 144 hours under vacuum of 0.1 Pa. After cooling, it was uniformly dispersed in a mixed solution of ethanol and water (volume ratio of ethanol to water is 50:1), with the ratio of powder to mixed solution being 50 g / L. After stirring at room temperature for 3 hours, the powder was filtered. The filter residue was dried at 60℃ for 8 hours under vacuum of 0.1 Pa to obtain composite carrier powder.

[0094] (2) Take 2L of tetrahydrofuran and 2.131g of dodecacarbonyltriruthenium and add them to a flask. Stir with a magnetic stirrer for 10 minutes. Add 50g of the composite carrier powder obtained in step (1). Impregnate at 30°C until the solution becomes completely transparent. Then, evaporate at 60°C until the solution is dry. Collect the powder and heat it for 10 minutes. -3 The composite carrier powder loaded with active metal ruthenium was obtained by calcination at 120℃ (heating rate of 8℃ / min) for 3 hours.

[0095] (3) Take 100g of the composite carrier powder loaded with active metal ruthenium obtained in step (2) and mix it with 17g of boehmite, 2g of bentonite, 3g of graphene, 30g of deionized water and 3g of acetic acid. After stirring evenly, place the above raw materials in a ZP-9A rotary tableting machine with a pressure of 25kN and use a cylindrical mold with a diameter of 3mm to obtain 3mm cylindrical catalyst particles.

[0096] (4) Place the 3mm cylindrical catalyst particles obtained in step (3) in a vacuum drying oven and dry them at 10°C. -1 After drying at 30℃ for 6 hours, the sample was placed in a tube furnace and evacuated to 10℃. -2 The ruthenium-based catalyst particles for ammonia synthesis were prepared by calcining at a vacuum of 1 Pa, heating to 60°C at a heating rate of 5°C / min and holding for 3 hours, and then heating to 400°C at a heating rate of 2°C / min and holding for 3 hours. The resulting 3 mm cylindrical particles were prepared. (The ruthenium loading in the ruthenium-based catalyst in this example is 1.3 wt%).

[0097] Example 4

[0098] The method for preparing the Ru-based catalyst for ammonia synthesis provided in this embodiment includes the following steps:

[0099] (1) Take 29.078g (0.1247mol) BaTiO3, 31.5g (0.748mol) CaH2 and 21.43g (0.1245mol) CeO2 respectively, mix them evenly, and heat them at 10°C. -3The powder was calcined at 610℃ for 144 hours under vacuum of 0.1 Pa. After cooling, it was uniformly dispersed in a mixed solution of ethanol and water (volume ratio of ethanol to water is 50:1), with the ratio of powder to mixed solution being 50 g / L. After stirring at room temperature for 3 hours, the powder was filtered. The filter residue was dried at 60℃ for 8 hours under vacuum of 0.1 Pa to obtain composite carrier powder.

[0100] (2) Take 2L of tetrahydrofuran and 2.131g of dodecacarbonyltriruthenium and add them to a flask. Stir with a magnetic stirrer for 10min. Add 50g of the composite carrier powder obtained in step (1). Impregnate at 30℃ until the solvent becomes completely transparent. Then, evaporate at 60℃ until the solution is dry. Collect the powder and heat it for 10 minutes. -3 The composite carrier powder loaded with active metal ruthenium was obtained by calcination at 120℃ (heating rate of 8℃ / min) for 3 hours.

[0101] (3) Take 100g of the composite carrier powder loaded with active metal ruthenium obtained in step (2) and mix it with 17g of boehmite, 2g of bentonite, 3g of graphene, 30g of deionized water and 3g of acetic acid. After stirring evenly, place the above raw materials in a ZP-9A rotary tableting machine with a pressure of 25kN and use a cylindrical mold with a diameter of 3mm to obtain 3mm cylindrical catalyst particles.

[0102] (4) Place the 3mm cylindrical catalyst particles obtained in step (3) in a vacuum drying oven and dry them at 10°C. -1 After drying at 30℃ for 6 hours, the sample was placed in a tube furnace and evacuated to 10℃. -2 The ruthenium-based catalyst particles for ammonia synthesis were prepared by calcining at a vacuum of 1 Pa, heating to 60°C at a heating rate of 5°C / min and holding for 3 hours, and then heating to 400°C at a heating rate of 2°C / min and holding for 3 hours. The resulting 3 mm cylindrical particles were prepared. (The ruthenium loading in the ruthenium-based catalyst in this example is 1.3 wt%).

[0103] Example 5

[0104] The method for preparing the Ru-based catalyst for ammonia synthesis provided in this embodiment includes the following steps:

[0105] (1) Take 29.078g BaTiO3, 60.2g (1.5mol) KH and 45.2g Gd2O3 respectively, mix them evenly, and heat them at 1000°C. -3 The powder was calcined at 610℃ for 144 hours under vacuum of 0.1 Pa. After cooling, it was uniformly dispersed in a mixed solution of ethanol and water (volume ratio of ethanol to water is 50:1), with the ratio of powder to mixed solution being 50 g / L. After stirring at room temperature for 3 hours, the powder was filtered. The filter residue was dried at 60℃ for 8 hours under vacuum of 0.1 Pa to obtain composite carrier powder.

[0106] (2) Take 2L of tetrahydrofuran and 2.131g of dodecacarbonyltriruthenium and add them to a flask. Stir with a magnetic stirrer for 10min. Add 50g of the composite carrier powder obtained in step (1). Impregnate at 30℃ until the solvent becomes completely transparent. Then, evaporate at 60℃ until the solution is dry. Collect the powder and heat it for 10 minutes. -3 The composite carrier powder loaded with active metal ruthenium was obtained by calcination at 120℃ (heating rate of 8℃ / min) for 3 hours.

[0107] (3) Take 100g of the composite carrier powder loaded with active metal ruthenium obtained in step (2) and mix it with 17g of boehmite, 2g of bentonite, 3g of graphene, 30g of deionized water and 3g of acetic acid. After stirring evenly, place the above raw materials in a ZP-9A rotary tableting machine with a pressure of 25kN and use a cylindrical mold with a diameter of 3mm to obtain 3mm cylindrical catalyst particles.

[0108] (4) Place the 3mm cylindrical catalyst particles obtained in step (3) in a vacuum drying oven and dry them at 10°C. -1 After drying at 30℃ for 6 hours, the sample was placed in a tube furnace and evacuated to 10℃. -2 The ruthenium-based catalyst particles for ammonia synthesis were prepared by calcining at a vacuum of 1 Pa, heating to 60°C at a heating rate of 5°C / min and holding for 3 hours, and then heating to 400°C at a heating rate of 2°C / min and holding for 3 hours. The resulting 3 mm cylindrical particles were prepared. (The ruthenium loading in the ruthenium-based catalyst in this example is 1.3 wt%).

[0109] Example 6

[0110] The method for preparing the Ru-based catalyst for ammonia synthesis provided in this embodiment includes the following steps:

[0111] (1) Take 2L of tetrahydrofuran and 2.664g of dodecacarbonyltriruthenium and add them to a flask. Stir with a magnetic stirrer for 10min. Add 50g of the composite carrier powder obtained in step (1) of Example 1. Impregnate at 30℃ until the solvent becomes completely transparent. Then, evaporate at 60℃ until the solution is dry. Collect the powder and heat it for 10 minutes. -3 The composite carrier powder loaded with active metal ruthenium was obtained by calcination at 120℃ (heating rate of 8℃ / min) for 3 hours.

[0112] (2) Take 100g of the composite carrier powder loaded with active metal ruthenium obtained in step (1) and mix it with 17g of boehmite, 2g of bentonite, 3g of graphene, 30g of deionized water and 3g of acetic acid. After stirring evenly, place the above raw materials in a ZP-9A rotary tableting machine with a pressure of 25kN and use a cylindrical mold with a diameter of 3mm to obtain 3mm cylindrical catalyst particles.

[0113] (3) Place the 3mm cylindrical catalyst particles obtained in step (2) in a vacuum drying oven and dry them at 10°C. -1 After drying at 30℃ for 6 hours, the sample was placed in a tube furnace and evacuated to 10℃. -2 The ruthenium-based catalyst particles for ammonia synthesis were prepared by calcining at a vacuum of 10 Pa, heating to 60 °C at a heating rate of 5 °C / min and holding for 3 h, and then heating to 400 °C at a heating rate of 2 °C / min and holding for 3 h. (In this embodiment, the proportion of ruthenium nanoparticles in the catalyst is about 1.63 wt%, that is, the ruthenium loading in the ruthenium-based catalyst in this embodiment is 1.63 wt%).

[0114] Example 7

[0115] The method for preparing the Ru-based catalyst for ammonia synthesis provided in this embodiment includes the following steps:

[0116] (1) Take 2L of tetrahydrofuran and 2.397g of dodecacarbonyltriruthenium and add them to a flask. Stir with a magnetic stirrer for 10min. Add 50g of the composite carrier powder obtained in step (1) of Example 1. Impregnate at 30℃ until the solvent becomes completely transparent. Then, evaporate at 60℃ until the solution is dry. Collect the powder and heat it for 10 minutes. -3 The composite carrier powder loaded with active metal ruthenium was obtained by calcination at 120℃ (heating rate of 8℃ / min) for 3 hours.

[0117] (2) Take 100g of the composite carrier powder loaded with active metal ruthenium obtained in step (1) and mix it with 17g of boehmite, 2g of bentonite, 3g of graphene, 30g of deionized water and 3g of acetic acid. After stirring evenly, place the above raw materials in a ZP-9A rotary tableting machine with a pressure of 25kN and use a cylindrical mold with a diameter of 3mm to obtain 3mm cylindrical catalyst particles.

[0118] (3) Place the 3mm cylindrical catalyst particles obtained in step (2) in a vacuum drying oven and dry them at 10°C. -1 After drying at 30℃ for 6 hours, the sample was placed in a tube furnace and evacuated to 10℃. -2 Under a vacuum of 10 Pa, the temperature was increased to 60°C at a heating rate of 5°C / min and held for 3 hours. Then, the temperature was increased to 400°C at a heating rate of 2°C / min and held for 3 hours for calcination to obtain 3 mm cylindrical ruthenium-based catalyst particles for ammonia synthesis (in this embodiment, the proportion of ruthenium nanoparticles in the catalyst is approximately 1.46 wt%, that is, the ruthenium loading in the ruthenium-based catalyst in this embodiment is 1.46 wt%).

[0119] Example 8

[0120] The method for preparing the Ru-based catalyst for ammonia synthesis provided in this embodiment includes the following steps:

[0121] (1) Take 2L of tetrahydrofuran and 1.865g of dodecacarbonyltriruthenium and add them to a flask. Stir with a magnetic stirrer for 10min. Add 50g of the composite carrier powder prepared in step (1) of Example 1 and impregnate at 30°C until the solvent becomes completely transparent. Then, evaporate at 60°C until the solution is dry. Collect the powder and heat it at 10°C. -3 The composite carrier powder loaded with active metal ruthenium was obtained by calcination at 120℃ (heating rate of 8℃ / min) for 3 hours.

[0122] (2) Take 100g of the composite carrier powder loaded with active metal ruthenium obtained in step (1) and mix it with 17g of boehmite, 2g of bentonite, 3g of graphene, 30g of deionized water and 3g of acetic acid. After stirring evenly, place the above raw materials in a ZP-9A rotary tableting machine with a pressure of 25kN and use a cylindrical mold with a diameter of 3mm to obtain 3mm cylindrical catalyst particles.

[0123] (3) Place the 3mm cylindrical catalyst particles obtained in step (2) in a vacuum drying oven and dry them at 10°C. -1 After drying at 30℃ for 6 hours, the sample was placed in a tube furnace and evacuated to 10℃. -2 The ruthenium-based catalyst particles for ammonia synthesis were prepared by calcining at a vacuum of 10 Pa, heating to 60 °C at a heating rate of 5 °C / min and holding for 3 h, and then heating to 400 °C at a heating rate of 2 °C / min and holding for 3 h. (In this example, the proportion of ruthenium nanoparticles in the catalyst is about 1.14 wt%, that is, the ruthenium loading in the ruthenium-based catalyst in this example is 1.14 wt%).

[0124] Example 9

[0125] The method for preparing the Ru-based catalyst for ammonia synthesis provided in this embodiment includes the following steps:

[0126] (1) Take 2L of tetrahydrofuran and 1.598g of dodecacarbonyltriruthenium and add them to a flask. Stir with a magnetic stirrer for 10min. Add 50g of the composite carrier powder prepared according to step (1) of Example 1 and impregnate at 30°C until the solvent becomes completely transparent. Then, evaporate at 60°C until the solution is dry. Collect the powder and heat it at 10°C. -3 The composite carrier powder loaded with active metal ruthenium was obtained by calcination at 120℃ (heating rate of 8℃ / min) for 3 hours.

[0127] (2) Take 100g of the composite carrier powder loaded with active metal ruthenium obtained in step (1) and mix it with 17g of boehmite, 2g of bentonite, 3g of graphene, 30g of deionized water and 3g of acetic acid. After stirring evenly, place the above raw materials in a ZP-9A rotary tableting machine with a pressure of 25kN and use a cylindrical mold with a diameter of 3mm to obtain 3mm cylindrical catalyst particles.

[0128] (3) Place the 3mm cylindrical catalyst particles obtained in step (2) in a vacuum drying oven and dry them at 10°C. -1 After drying at 30℃ for 6 hours, the sample was placed in a tube furnace and evacuated to 10℃. -2 Under a vacuum of 10 Pa, the temperature was increased to 60°C at a heating rate of 5°C / min and held for 3 hours. Then, the temperature was increased to 400°C at a heating rate of 2°C / min and held for 3 hours for calcination to obtain 3 mm cylindrical ruthenium-based catalyst particles for ammonia synthesis (in this embodiment, the proportion of ruthenium nanoparticles in the catalyst is approximately 0.98 wt%, that is, the ruthenium loading in the ruthenium-based catalyst in this embodiment is 0.98 wt%).

[0129] Example 10

[0130] The method for preparing the Ru-based catalyst for ammonia synthesis provided in this embodiment includes the following steps:

[0131] (1) Take 2L of tetrahydrofuran and 2.131g of dodecacarbonyltriruthenium and add them to a flask. Stir with a magnetic stirrer for 10min. Add 50g of the composite carrier powder prepared according to step (1) of Example 1 and impregnate at 30°C until the solvent becomes completely transparent. Then, evaporate at 60°C until the solution is dry. Collect the powder and heat it at 10°C. -3 The composite carrier powder loaded with active metal ruthenium was obtained by calcination at 120℃ (heating rate of 8℃ / min) for 3 hours.

[0132] (2) Take 100g of the composite carrier powder loaded with active metal ruthenium obtained in step (1) and mix it with 10g of boehmite, 2g of bentonite, 3g of graphene, 30g of deionized water and 3g of acetic acid. After stirring evenly, place the above raw materials in a ZP-9A rotary tableting machine with a pressure of 25kN and use a cylindrical mold with a diameter of 3mm to obtain 3mm cylindrical catalyst particles.

[0133] (3) Place the 3mm cylindrical catalyst particles obtained in step (2) in a vacuum drying oven and dry them at 10°C. -1 After drying at 30℃ for 6 hours, the sample was placed in a tube furnace and evacuated to 10℃. -2The ruthenium-based catalyst particles for ammonia synthesis were prepared by calcining at a vacuum of 10 Pa, heating to 60 °C at a heating rate of 5 °C / min and holding for 3 h, and then heating to 400 °C at a heating rate of 2 °C / min and holding for 3 h. (In this embodiment, the proportion of ruthenium nanoparticles in the catalyst is about 1.44 wt%, that is, the ruthenium loading in the ruthenium-based catalyst in this embodiment is 1.44 wt%).

[0134] Example 11

[0135] The method for preparing the Ru-based catalyst for ammonia synthesis provided in this embodiment includes the following steps:

[0136] (1) Take 2L of tetrahydrofuran and 2.131g of dodecacarbonyltriruthenium and add them to a flask. Stir with a magnetic stirrer for 10min. Add 50g of the composite carrier powder prepared according to step (1) of Example 1 and impregnate at 30°C until the solvent becomes completely transparent. Then, evaporate at 60°C until the solution is dry. Collect the powder and heat it at 10°C. -3 The composite carrier powder loaded with active metal ruthenium was obtained by calcination at 120℃ (heating rate of 8℃ / min) for 3 hours.

[0137] (2) Take 100g of the composite carrier powder loaded with active metal ruthenium obtained in step (2) and mix it with 17g of boehmite, 2g of bentonite, 1g of graphene, 30g of deionized water and 3g of acetic acid. After stirring evenly, place the above raw materials in a ZP-9A rotary tableting machine with a pressure of 25kN and use a cylindrical mold with a diameter of 3mm to obtain 3mm cylindrical catalyst particles.

[0138] (3) Place the 3mm cylindrical catalyst particles obtained in step (2) in a vacuum drying oven and dry them at 10°C. -1 After drying at 30℃ for 6 hours, the sample was placed in a tube furnace and evacuated to 10℃. -2 The catalyst was calcined at a vacuum of 10 Pa, heated to 60 °C at a heating rate of 5 °C / min and held for 3 h, and then heated to 400 °C at a heating rate of 2 °C / min and held for 3 h to obtain 3 mm cylindrical ruthenium-based catalyst particles for ammonia synthesis (in this example, the proportion of ruthenium nanoparticles in the catalyst is about 1.3 wt%).

[0139] Example 12

[0140] The method for preparing the Ru-based catalyst for ammonia synthesis provided in this embodiment includes the following steps:

[0141] (1) Take 50g of the composite carrier powder obtained in step 1 of Example 1 and disperse it evenly in a 0.1M calcium chloride methanol solution, wherein the ratio of powder to solution is 50g / L. Evaporate at 40°C until the solution is dry, and vacuum dry the collected powder overnight to obtain the composite carrier powder with the electronic additive calcium.

[0142] (2) Take 2L of tetrahydrofuran and 2.131g of dodecacarbonyltriruthenium and add them to a flask. Stir with a magnetic stirrer for 10 minutes. Add 50g of the composite carrier powder obtained in step (1). Impregnate at 30°C until the solvent becomes completely transparent. Then, evaporate at 60°C until the solution is dry. Collect the powder and heat it for 10 minutes. -3 The composite carrier powder loaded with active metal ruthenium was obtained by calcination at 120℃ (heating rate of 8℃ / min) for 3 hours.

[0143] (3) Take 100g of the composite carrier powder loaded with active metal ruthenium obtained in step (2) and mix it with 17g of boehmite, 2g of bentonite, 3g of graphene, 30g of deionized water and 3g of acetic acid. After stirring evenly, place the above raw materials in a ZP-9A rotary tableting machine with a pressure of 25kN and use a cylindrical mold with a diameter of 3mm to obtain 3mm cylindrical catalyst particles.

[0144] (4) Place the 3mm cylindrical catalyst particles obtained in step (3) in a vacuum drying oven and dry them at 10°C. -1 After drying at 30℃ for 6 hours, the sample was placed in a tube furnace and evacuated to 10℃. -2 The catalyst was calcined at a vacuum of 10 Pa, heated to 60 °C at a heating rate of 5 °C / min and held for 3 h, and then heated to 400 °C at a heating rate of 2 °C / min and held for 3 h to obtain 3 mm cylindrical ruthenium-based catalyst particles for ammonia synthesis (in this example, the proportion of ruthenium nanoparticles in the catalyst is about 1.3 wt%).

[0145] Example 13

[0146] The method for preparing the Ru-based catalyst for ammonia synthesis provided in this embodiment includes the following steps:

[0147] (1) Take 50g of the composite carrier powder obtained according to step (1) of Example 1 and disperse it evenly in a 0.1M potassium chloride methanol solution, wherein the ratio of powder to solution is 50g / L. Evaporate at 40°C until the solution is dry, and vacuum dry the collected powder overnight to obtain the composite carrier powder with potassium electronic additive.

[0148] (2) Take 2L of tetrahydrofuran and 2.131g of dodecacarbonyltriruthenium and add them to a flask. Stir with a magnetic stirrer for 10 minutes. Add 50g of the composite carrier powder obtained in step (1). Impregnate at 30°C until the solvent becomes completely transparent. Then, evaporate at 60°C until the solution is dry. Collect the powder and heat it for 10 minutes. -3 The composite carrier powder loaded with active metal ruthenium was obtained by calcination at 120℃ (heating rate of 8℃ / min) for 3 hours.

[0149] (3) Take 100g of the composite carrier powder loaded with active metal ruthenium obtained in step (2) and mix it with 17g of boehmite, 2g of bentonite, 3g of graphene, 30g of deionized water and 3g of acetic acid. After stirring evenly, place the above raw materials in a ZP-9A rotary tableting machine with a pressure of 25kN and use a cylindrical mold with a diameter of 3mm to obtain 3mm cylindrical catalyst particles.

[0150] (4) Place the 3mm cylindrical catalyst particles obtained in step (3) in a vacuum drying oven and dry them at 10°C. -1 After drying at 30℃ for 6 hours, the sample was placed in a tube furnace and evacuated to 10℃. -2 The catalyst was calcined at a vacuum of 10 Pa, heated to 60 °C at a heating rate of 5 °C / min and held for 3 h, and then heated to 400 °C at a heating rate of 2 °C / min and held for 3 h to obtain 3 mm cylindrical ruthenium-based catalyst particles for ammonia synthesis (in this example, the proportion of ruthenium nanoparticles in the catalyst is about 1.3 wt%).

[0151] Example 14

[0152] The method for preparing the Ru-based catalyst for ammonia synthesis provided in this embodiment includes the following steps:

[0153] (1) Take 50g of the composite carrier powder obtained in step (1) of Example 1 and disperse it evenly in a 0.1M potassium acetate methanol solution, wherein the ratio of powder to solution is 50g / L. Evaporate at 40℃ until the solution is dried, and vacuum dry the collected powder overnight to obtain the composite carrier powder with the electronic auxiliary potassium.

[0154] (2) Take 2L of tetrahydrofuran and 2.131g of dodecacarbonyltriruthenium and add them to a flask. Stir with a magnetic stirrer for 10 minutes. Add 50g of the composite carrier powder obtained in step (1). Impregnate at 30°C until the solvent becomes completely transparent. Then, evaporate at 60°C until the solution is dry. Collect the powder and heat it for 10 minutes. -3 The composite carrier powder loaded with active metal ruthenium was obtained by calcination at 120℃ (heating rate of 8℃ / min) for 3 hours.

[0155] (3) Take 100g of the composite carrier powder loaded with active metal ruthenium obtained in step (2) and mix it with 17g of boehmite, 2g of bentonite, 3g of graphene, 30g of deionized water and 3g of acetic acid. After stirring evenly, place the above raw materials in a ZP-9A rotary tableting machine with a pressure of 25kN and use a cylindrical mold with a diameter of 3mm to obtain 3mm cylindrical catalyst particles.

[0156] (4) Place the 3mm cylindrical catalyst particles obtained in step (3) in a vacuum drying oven and dry them at 10°C. -1 After drying at 30℃ for 6 hours, the sample was placed in a tube furnace and evacuated to 10℃. -2 The catalyst was calcined at a vacuum of 10 Pa, heated to 60 °C at a heating rate of 5 °C / min and held for 3 h, and then heated to 400 °C at a heating rate of 2 °C / min and held for 3 h to obtain 3 mm cylindrical ruthenium-based catalyst particles for ammonia synthesis (in this example, the proportion of ruthenium nanoparticles in the catalyst is about 1.3 wt%).

[0157] Example 15

[0158] The method for preparing the Ru-based catalyst for ammonia synthesis provided in this embodiment includes the following steps:

[0159] (1) Take 50g of the composite carrier powder obtained according to step (1) of Example 1 and disperse it evenly in a 0.5M potassium acetate methanol solution, wherein the ratio of powder to solution is 50g / L. Evaporate at 40°C until the solution is dry, and vacuum dry the collected powder overnight to obtain the composite carrier powder with potassium electronic additive.

[0160] (2) Take 2L of tetrahydrofuran and 2.131g of dodecacarbonyltriruthenium and add them to a flask. Stir with a magnetic stirrer for 10 minutes. Add 50g of the composite carrier powder obtained in step (1). Impregnate at 30°C until the solvent becomes completely transparent. Then, evaporate at 60°C until the solution is dry. Collect the powder and heat it for 10 minutes. -3 The composite carrier powder loaded with active metal ruthenium was obtained by calcination at 120℃ (heating rate of 8℃ / min) for 3 hours.

[0161] (3) Take 100g of the composite carrier powder loaded with active metal ruthenium obtained in step (2) and mix it with 17g of boehmite, 2g of bentonite, 3g of graphene, 30g of deionized water and 3g of acetic acid. After stirring evenly, place the above raw materials in a ZP-9A rotary tableting machine with a pressure of 25kN and use a cylindrical mold with a diameter of 3mm to obtain 3mm cylindrical catalyst particles.

[0162] (4) Place the 3mm cylindrical catalyst particles obtained in step (3) in a vacuum drying oven and dry them at 10°C. -1After drying at 30℃ for 6 hours, the sample was placed in a tube furnace and evacuated to 10℃. -2 The catalyst was calcined at a vacuum of 10 Pa, heated to 60 °C at a heating rate of 5 °C / min and held for 3 h, and then heated to 400 °C at a heating rate of 2 °C / min and held for 3 h to obtain 3 mm cylindrical ruthenium-based catalyst particles for ammonia synthesis (in this example, the proportion of ruthenium nanoparticles in the catalyst is about 1.3 wt%).

[0163] Example 16

[0164] The method for preparing the Ru-based catalyst for ammonia synthesis provided in this embodiment includes the following steps:

[0165] (1) Take 31.5g CaH2 and 90.405g gadolinium oxide respectively, mix them evenly, and heat at 10 -3 The powder was calcined at 610℃ for 144 hours under vacuum of 0.1 Pa. After cooling, it was uniformly dispersed in a mixed solution of ethanol and water (volume ratio of ethanol to water is 50:1), with the ratio of powder to solution being 50 g / L. After stirring at room temperature for 3 hours, the powder was filtered. The filter residue was dried at 60℃ for 8 hours under vacuum of 0.1 Pa to obtain composite carrier powder.

[0166] (2) Take 2L of tetrahydrofuran and 2.131g of dodecacarbonyltriruthenium and add them to a flask. Stir with a magnetic stirrer for 10 minutes. Add 50g of the composite carrier powder obtained in step (1). Impregnate at 30°C until the solvent becomes completely transparent. Then, evaporate at 60°C until the solution is dry. Collect the powder and heat it for 10 minutes. -3 The composite carrier powder loaded with active metal ruthenium was obtained by calcination at 120℃ (heating rate of 8℃ / min) for 3 hours.

[0167] (3) Take 100g of the composite carrier powder loaded with active metal ruthenium obtained in step (2) and mix it with 17g of boehmite, 2g of bentonite, 3g of graphene, 30g of deionized water and 3g of acetic acid. After stirring evenly, place the above raw materials in a ZP-9A rotary tableting machine with a pressure of 25kN and use a cylindrical mold with a diameter of 3mm to obtain 3mm cylindrical catalyst particles.

[0168] (4) Place the 3mm cylindrical catalyst particles obtained in step (3) in a vacuum drying oven and dry them at 10°C. -1 After drying at 30℃ for 6 hours, the sample was placed in a tube furnace and evacuated to 10℃. -2 The catalyst was calcined at a vacuum of 10 Pa, heated to 60 °C at a heating rate of 5 °C / min and held for 3 h, and then heated to 400 °C at a heating rate of 2 °C / min and held for 3 h to obtain 3 mm cylindrical ruthenium-based catalyst particles for ammonia synthesis (in this example, the proportion of ruthenium nanoparticles in the catalyst is about 1.3 wt%).

[0169] Example 17

[0170] The method for preparing the Ru-based catalyst for ammonia synthesis provided in this embodiment includes the following steps:

[0171] (1) Take 58.16g BaTiO3, 31.5g CaH2 and 45.2g gadolinium oxide respectively, mix them evenly, and heat at 10 -3 The powder was calcined at 610℃ for 144 hours under vacuum of 0.1 Pa. After cooling, it was uniformly dispersed in a mixed solution of ethanol and water (volume ratio of ethanol to water is 50:1), with the ratio of powder to solution being 50 g / L. After stirring at room temperature for 3 hours, the powder was filtered. The filter residue was dried at 60℃ for 8 hours under vacuum of 0.1 Pa to obtain composite carrier powder.

[0172] (2) Take 2L of tetrahydrofuran and 2.131g of dodecacarbonyltriruthenium and add them to a flask. Stir with a magnetic stirrer for 10 minutes. Add 50g of the composite carrier powder obtained in step (1). Impregnate at 30°C until the solvent becomes completely transparent. Then, evaporate at 60°C until the solution is dry. Collect the powder and heat it for 10 minutes. -3 The composite carrier powder loaded with active metal ruthenium was obtained by calcination at 120℃ (heating rate of 8℃ / min) for 3 hours.

[0173] (3) Take 100g of the composite carrier powder loaded with active metal ruthenium obtained in step (2) and mix it with 17g of boehmite, 2g of bentonite, 3g of graphene, 30g of deionized water and 3g of acetic acid. After stirring evenly, place the above raw materials in a ZP-9A rotary tableting machine with a pressure of 25kN and a 3mm columnar mold to obtain 3mm columnar catalyst particles.

[0174] (4) Place the 4mm spherical catalyst particles obtained in step (3) in a vacuum drying oven and dry them at 10°C. -1 After drying at 30℃ for 6 hours, the sample was placed in a tube furnace and evacuated to 10℃. -2 The catalyst was calcined at a vacuum of 10 Pa, heated to 60 °C at a heating rate of 5 °C / min and held for 3 h, and then heated to 400 °C at a heating rate of 2 °C / min and held for 3 h to obtain 4 mm spherical ruthenium-based catalyst particles for ammonia synthesis (in this example, the proportion of ruthenium nanoparticles in the catalyst is about 1.3 wt%).

[0175] Comparative Example 1

[0176] The preparation method of the Ru-based catalyst for ammonia synthesis provided in this comparative example includes the following steps:

[0177] (1) Take 58.16g of BaTiO3 and in 10 -3The powder was calcined at 610℃ for 144 hours under vacuum of 0.1 Pa. After cooling, it was uniformly dispersed in a mixed solution of ethanol and water (volume ratio of ethanol to water is 50:1), with the ratio of powder to solution being 50 g / L. After stirring at room temperature for 3 hours, the powder was filtered. The filter residue was dried at 60℃ for 8 hours under vacuum of 0.1 Pa to obtain the carrier powder.

[0178] (2) Take 2L of tetrahydrofuran and 2.131g of dodecacarbonyltriruthenium and add them to a flask. Stir with a magnetic stirrer for 10 minutes. Add 50g of the carrier powder obtained in step (1) and impregnate at 30°C until the solvent becomes completely transparent. Then, evaporate the solution at 60°C until it is dry. Collect the powder and heat it for 10 minutes. -3 The carrier powder loaded with active metal ruthenium was obtained by calcination at 120℃ (heating rate of 8℃ / min) for 3 hours.

[0179] (3) Take 100g of the carrier powder loaded with active metal ruthenium obtained in step (2) and mix it with 17g of boehmite, 2g of bentonite, 3g of graphene, 30g of deionized water and 3g of acetic acid. After stirring evenly, place the above raw materials in a ZP-9A rotary tableting machine with a pressure of 25kN and use a cylindrical mold with a diameter of 3mm to obtain 3mm cylindrical catalyst particles.

[0180] (4) Place the 3mm cylindrical catalyst particles obtained in step (3) in a vacuum drying oven and dry them at 10°C. -1 After drying at 30℃ for 6 hours, the sample was placed in a tube furnace and evacuated to 10℃. -2 The catalyst was calcined at a vacuum of 10 Pa, heated to 60 °C at a heating rate of 5 °C / min and held for 3 h, and then heated to 400 °C at a heating rate of 2 °C / min and held for 3 h to obtain 3 mm cylindrical ruthenium-based catalyst particles for ammonia synthesis (in this comparative example, the proportion of ruthenium nanoparticles in the catalyst is about 1.3 wt%).

[0181] Comparative Example 2

[0182] The preparation method of the Ru-based catalyst for ammonia synthesis provided in this comparative example includes the following steps:

[0183] (1) Take 29.078g BaTiO3, 31.5g CaH2 and 45.20g Gd2O3 respectively, mix them evenly, and heat them at 10 -3 The powder was calcined at 610℃ for 144 hours under vacuum of 0.1 Pa. After cooling, it was uniformly dispersed in ethanol at a ratio of 50 g / L. After stirring at room temperature for 3 hours, it was filtered. The filter residue was dried at 60℃ for 8 hours under vacuum of 0.1 Pa to obtain composite carrier powder.

[0184] (2) Take 2L of tetrahydrofuran and 2.131g of dodecacarbonyltriruthenium and add them to a flask. Stir with a magnetic stirrer for 10 minutes. Add 50g of the composite carrier powder obtained in step (1). Impregnate at 30°C until the solvent becomes completely transparent. Then, evaporate at 60°C until the solution is dry. Collect the powder and heat it for 10 minutes. -3 The composite carrier powder loaded with active metal ruthenium was obtained by calcination at 120℃ (heating rate of 8℃ / min) for 3 hours.

[0185] (3) Take 100g of the carrier powder loaded with active metal ruthenium prepared in step (2) and mix it with 17g of boehmite, 2g of bentonite, 3g of graphene, 30g of deionized water and 3g of acetic acid. After stirring evenly, place the above raw materials in a ZP-9A rotary tableting machine with a pressure of 25kN and use a 4mm spherical mold to obtain 4mm spherical catalyst particles.

[0186] (4) Place the 4mm spherical catalyst particles obtained in step (3) in a vacuum drying oven and dry them at 10°C. -1 After drying at 30℃ for 6 hours, the sample was placed in a tube furnace and evacuated to 10℃. -2 The catalyst was calcined at a vacuum of 10 Pa, heated to 60 °C at a heating rate of 5 °C / min and held for 3 h, and then heated to 400 °C at a heating rate of 2 °C / min and held for 3 h to obtain 4 mm spherical ruthenium-based catalyst particles for ammonia synthesis (in this comparative example, the proportion of ruthenium nanoparticles in the catalyst is about 1.3 wt%).

[0187] Comparative Example 3

[0188] The preparation method of the Ru-based catalyst for ammonia synthesis provided in this comparative example includes the following steps:

[0189] (1) Take 58.16g of BaTiO3 and 90.4g of Gd2O3 respectively, mix them evenly at 10 -3 The powder was calcined at 610℃ for 144 hours under vacuum of 0.1 Pa. After cooling, it was uniformly dispersed in a mixed solution of ethanol and water (volume ratio of ethanol to water is 50:1), with the ratio of powder to mixed solution being 50 g / L. After stirring at room temperature for 3 hours, the powder was filtered. The filter residue was dried at 60℃ for 8 hours under vacuum of 0.1 Pa to obtain composite carrier powder.

[0190] (2) Take 2L of tetrahydrofuran and 2.131g of dodecacarbonyltriruthenium and add them to a flask. Stir with a magnetic stirrer for 10 minutes. Add 50g of the composite carrier powder obtained in step (1). Impregnate at 30°C until the solvent becomes completely transparent. Then, evaporate at 60°C until the solution is dry. Collect the powder and heat it for 10 minutes. -3 The composite carrier powder loaded with active metal ruthenium was obtained by calcination at 120℃ (heating rate of 8℃ / min) for 3 hours.

[0191] (3) Take 100g of the composite carrier powder loaded with active metal ruthenium obtained in step (2) and mix it with 17g of boehmite, 2g of bentonite, 3g of graphene, 30g of deionized water and 3g of acetic acid. After stirring evenly, place the above raw materials in a ZP-9A rotary tableting machine with a pressure of 25kN and use a cylindrical mold with a diameter of 3mm to obtain 3mm cylindrical catalyst particles.

[0192] (4) Place the 3mm cylindrical catalyst particles obtained in step (3) in a vacuum drying oven and dry them at 10°C. -1 After drying at 30℃ for 6 hours, the sample was placed in a tube furnace and evacuated to 10℃. -2 The catalyst was calcined at a vacuum of 10 Pa, heated to 60 °C at a heating rate of 5 °C / min and held for 3 h, and then heated to 400 °C at a heating rate of 2 °C / min and held for 3 h to obtain 3 mm cylindrical ruthenium-based catalyst particles for ammonia synthesis (in this comparative example, the proportion of ruthenium nanoparticles in the catalyst is about 1.3 wt%).

[0193] Comparative Example 4

[0194] The method for preparing the Ru-based catalyst for ammonia synthesis provided in this embodiment includes the following steps:

[0195] (1) Take 31.5g CaH2 and 90.4g Gd2O3 respectively, mix them evenly in 10 -3 The powder was calcined at 610℃ for 144 hours under vacuum of 0.1 Pa. After cooling, it was uniformly dispersed in an ethanol solution with an ammonium chloride concentration of 0.1 M, wherein the ratio of powder to ethanol solution was 50 g / L. After stirring at room temperature for 3 hours, it was filtered. The filter residue was dried at 60℃ for 8 hours under vacuum of 0.1 Pa to obtain composite carrier powder.

[0196] (2) Take 2L of tetrahydrofuran and 2.131g of dodecacarbonyltriruthenium and add them to a flask. Stir with a magnetic stirrer for 10 minutes. Add 50g of the composite carrier powder obtained in step (1). Impregnate at 30°C until the solvent becomes completely transparent. Then, evaporate at 60°C until the solution is dry. Collect the powder and heat it for 10 minutes. -3 The composite carrier powder loaded with active metal ruthenium was obtained by calcination at 120℃ (heating rate of 8℃ / min) for 3 hours.

[0197] (3) Take 100g of the composite carrier powder loaded with active metal ruthenium obtained in step (2) and mix it with 17g of boehmite, 2g of bentonite, 3g of graphene, 30g of deionized water and 3g of acetic acid. After stirring evenly, place the above raw materials in a ZP-9A rotary tableting machine with a pressure of 25kN and use a 3mm columnar mold to obtain 3mm columnar catalyst particles.

[0198] (4) Place the 3mm columnar catalyst particles obtained in step (3) in a vacuum drying oven and dry them at 10°C. -1 After drying at 30℃ for 6 hours, the sample was placed in a tube furnace and evacuated to 10℃. -2 The catalyst was calcined at a vacuum of 10 Pa, heated to 60 °C at a heating rate of 5 °C / min and held for 3 h, and then heated to 400 °C at a heating rate of 2 °C / min and held for 3 h to obtain 4 mm spherical ruthenium-based catalyst particles for ammonia synthesis (in this comparative example, the proportion of ruthenium nanoparticles in the catalyst is about 1.3 wt%).

[0199] Catalyst performance evaluation:

[0200] Take 2 mL of each catalyst prepared in each example and comparative example, and the gas hourly space velocity (GHSV) of the reaction is 10000 h⁻¹. -1 The ammonia synthesis conversion rate was determined in a fixed-bed reactor. The reaction gas composition was a mixture of 25% N2 and 75% H2. After the catalyst was pre-reduced at 400℃ and atmospheric pressure for 15 hours, the ammonia concentration at the reactor outlet was tested at 400℃ and 5MPa or 400℃ and 8MPa (the activity test method refers to the national standard HG-T-5585-2019). The concentration determination method refers to the "Nitrogen Fertilizer Plant Production Analysis Procedure". Gas was collected from the reactor outlet using a sampling gas bag. 3 mL of 0.05 mol / L H2SO4 standard solution, 100 mL of ultrapure water, and 2 drops of methyl red indicator were added to a Bordeaux absorption bottle. Figure 2 Connect the instrument, operate the level bottle, adjust the sealing liquid in the gas measuring tube to zero, connect the inlet of the absorption tube to the sampling gas bag, and the outlet to the gas measuring tube. Control the gas flow rate; bubbling should be 2-3 bubbles per second. When half of the solution in the absorption bottle changes from red to yellow, the endpoint has been reached. Read the residual gas volume. The ammonia content in the sample gas is expressed as a volume percentage and calculated using the following formula:

[0201]

[0202] in:

[0203] C represents the concentration of the standard sulfuric acid solution used in the experiment, in mol / L;

[0204] V0 is the volume of the standard sulfuric acid solution used in the experiment, in mL;

[0205] V1 is the residual volume of sulfuric acid after absorbing ammonia, in mL;

[0206] T represents the experimental test temperature, in °C.

[0207] Compressive strength evaluation: The mechanical strength of the catalyst particles prepared in each example and comparative example was tested according to HG / T2783-2011 (Determination of crushing resistance of fertilizer catalyst particles) using the DL5 intelligent particle strength tester of Dalian Penghui Technology Development Co., Ltd.

[0208] The test results are shown in Table 1.

[0209] Table 1. Evaluation results of catalyst performance and compressive strength of each comparative example.

[0210]

[0211] By comparing Example 1 with Comparative Example 1, it can be seen that under the same treatment conditions, the ammonia synthesis catalytic performance of the composite support is more than 6 times higher than that of barium titanate alone. Rare earth metal hydrides and alkali metal and / or alkaline earth metal oxides are the key components of the composite support.

[0212] A comparison of Example 1 and Comparative Example 2 reveals that the mixed solvent treatment in the room-temperature solution reaction is crucial in the method of this invention, significantly impacting the performance of the final composite support. The presence of water in this process is critical, as it maintains the solution's neutrality and hydrolyzes unreacted, highly reactive alkali metals and / or alkaline earth metals into oxides, reducing risks and uncertainties in subsequent processing. Furthermore, it allows the alkali metals and / or alkaline earth metals to be uniformly dispersed as oxides on the surface of the composite metal salt, acting as an electronic aid to enhance the catalytic activity of the catalyst prepared from the final composite support. Moreover, the comparison between Example 1 and Comparative Example 2 shows that rare earth oxides do not exhibit good catalytic performance if they are not converted into hydrides.

[0213] A comparison between Example 16 and Comparative Example 4 also reveals that retaining alkali metal and / or alkaline earth metal salts is crucial. In Comparative Example 4, ammonium chloride is a strong acid and a weak base, and a concentration of 0.1 M makes the solution weakly acidic. Even with weakly acidic treatment, it is not conducive to the formation of the composite support and the catalytic effect of the catalyst in ammonia synthesis.

[0214] Examples 3 and 5 illustrate that, in addition to calcium hydride, other hydrogen-containing alkali metal and alkaline earth metal hydrides can also convert rare earth oxides in composite metal salts into hydrides, resulting in catalysts with excellent catalytic performance. However, given the different decomposition temperatures of different alkali metals and / or alkaline earth metal hydrides, the optimal formation conditions for their composite supports will differ.

[0215] Example 4 illustrates that, in addition to gadolinium oxide, hydrides formed by the transformation of other rare earth oxides can also give the final shaped catalyst excellent catalytic performance. However, given that the hydrogenation temperatures of different rare earth metal hydrides are different, the optimal formation conditions suitable for gadolinium hydride may not be suitable for other rare earth metal hydrides, and there will be some differences.

[0216] A comparison of Example 1 with Examples 6, 7, 8, and 9 reveals that the loading ratio of precious metals does indeed affect the catalytic performance of the final catalyst, but the degree of influence is not significant within a certain range. Commercial catalysts require a comprehensive consideration of performance and cost to select an optimal loading ratio of precious metals.

[0217] A comparison of Example 1 with Examples 10 and 11 shows that the molding raw materials can affect the performance of the final catalyst and the strength of the particles to a certain extent. Too low a content of the first binder and lubricant both have an adverse effect on the catalytic performance of the final molded catalyst particles.

[0218] Examples 12, 13, 14, and 15 illustrate that suitable electronic additives can either enhance or weaken the catalytic performance of a catalyst, and it is necessary to find suitable additive salts and dosages.

[0219] Examples 16 and 17 illustrate that a certain amount of BaTiO3 can improve the catalytic performance of the final catalyst, but excessive barium titanate is detrimental to the catalytic performance of the final catalyst. Too much barium titanate will inhibit the formation of rare earth metal hydrides and ultimately weaken the electron-donating ability of the composite support, which manifests as a decrease in the performance of the catalyst in catalyzing ammonia synthesis under the same noble metal loading.

[0220] In summary, under otherwise unchanged conditions, the composite support ratio and preparation method of the present invention have a significant impact on the ammonia synthesis performance of the catalyst. The preparation process of the composite support must contain alkali metal and / or alkaline earth metal hydrides, and must contain rare earth metal oxides. A certain amount of barium titanate and an appropriate amount of electronic additives can further enhance the catalytic performance of the final catalyst. The solution reaction conditions in the composite support preparation process must be neutral or alkaline. The morphology of the catalyst has a certain impact on the final performance, but it is mainly caused by the difference in specific surface area.

[0221] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A ruthenium-based catalyst for ammonia synthesis, characterized in that, It includes a composite carrier and an active component, wherein the active component is loaded on the composite carrier; The raw materials for the composite carrier are metal hydrides, rare earth metal oxides, and barium titanate. The active component is ruthenium; The ruthenium in the ruthenium-based catalyst accounts for 0.5-2% by mass; The metal hydride is an alkali metal hydride or an alkaline earth metal hydride. The rare earth metal oxide is an oxide of rare earth element; The metal hydride is selected from sodium hydride, potassium hydride, magnesium hydride, or calcium hydride; The rare earth metal oxide is selected from cerium oxide, gadolinium oxide, or yttrium oxide; The method for preparing the ruthenium-based catalyst for ammonia synthesis includes the following steps: mixing a metal hydride with a rare earth metal oxide and barium titanate, performing a first calcination, dispersing the mixture in a mixed solution of ethanol and water after cooling, separating the solid and liquid after standing, and drying the filter residue under vacuum to obtain a composite support; mixing tetrahydrofuran and ruthenium salt, stirring, and adding the composite support; after the solution becomes completely transparent, rotary evaporating until the solution is dry, and then performing a second calcination to obtain a composite support loaded with active metal ruthenium, which is the ruthenium-based catalyst for ammonia synthesis. The first calcination was carried out under vacuum conditions.

2. The ruthenium-based catalyst for ammonia synthesis according to claim 1, characterized in that, Its raw materials also include electronic additives, which are selected from potassium acetate, sodium acetate, calcium acetate, potassium chloride, sodium chloride, calcium chloride, potassium nitrate, sodium nitrate, or calcium nitrate.

3. A method for preparing a ruthenium-based catalyst for ammonia synthesis as described in any one of claims 1-2, characterized in that, When no electronic additives are present, the process includes the following steps: mixing a metal hydride with a rare earth metal oxide and barium titanate, performing a first calcination, cooling and dispersing the mixture in a mixed solution of ethanol and water, allowing it to stand and then separating the solid and liquid components, drying the filter residue under vacuum to obtain a composite support; mixing tetrahydrofuran and ruthenium salt, stirring and adding the composite support, and after the solution becomes completely transparent, rotary evaporating until the solution is dry, and then performing a second calcination to obtain a composite support loaded with active metal ruthenium, which is the ruthenium-based catalyst used for ammonia synthesis; When containing electronic additives, the process includes the following steps: mixing a metal hydride with a rare earth metal oxide and barium titanate, performing a first calcination, cooling and dispersing the mixture in a mixed solution of ethanol and water, allowing it to stand and then separating the solid and liquid components, and vacuum drying the filter residue to obtain a composite support; mixing the composite support with a methanol solution containing electronic additives, rotary evaporating until the solution is dry, and vacuum drying the resulting powder to obtain a composite support containing electronic additives; mixing tetrahydrofuran and ruthenium salt, stirring and then adding the composite support containing electronic additives, and after the solution becomes completely transparent, rotary evaporating until the solution is dry, and the resulting powder undergoing a second calcination to obtain a composite support loaded with active metal ruthenium, which is the ruthenium-based catalyst used for ammonia synthesis.

4. The method for preparing the ruthenium-based catalyst for ammonia synthesis according to claim 3, characterized in that, The molar ratio of the rare earth metal oxide, metal hydride and barium titanate is (0.1-1):(1-6):(0-1), wherein the number of moles of barium titanate is not 0; And / or, the temperature of the first calcination is 400-800 ℃, and the time of the first calcination is 5-168 h; And / or, the second calcination temperature is 120-150 ℃, and the second calcination time is 3-5 h.

5. A method for forming a ruthenium-based catalyst for ammonia synthesis according to any one of claims 1-2, characterized in that, The process includes the following steps: mixing a first binder, a second binder, a solid lubricant, an acid, a liquid lubricant, and the ruthenium-based catalyst evenly, and then sequentially compressing, drying, and calcining the mixture to obtain a shaped ruthenium-based catalyst.

6. The method for forming the ruthenium-based catalyst according to claim 5, characterized in that, The mass ratio of the first binder, the second binder, the liquid lubricant, and the ruthenium-based catalyst is 1:(0-1):(0.1-20):(4-20), wherein the amount of the second binder added is not zero.

7. The use of a ruthenium-based catalyst for ammonia synthesis as described in any one of claims 1-2, or a shaped ruthenium-based catalyst obtained by the shaping method according to any one of claims 5-6, in ammonia synthesis.

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