Binuclear Ru-based ammonia cracking hydrogen production catalyst and its preparation method and application

Abstract

The present application relates to the field of catalysts, and specifically, provides a binuclear Ru-based ammonia cracking hydrogen production catalyst and its preparation method and application. The preparation method of the binuclear Ru-based ammonia cracking hydrogen production catalyst comprises the following steps: S1, mixing Ru metal precursor, solvent and ligand evenly to obtain a first solution; S2, adding a carrier to the first solution, mixing evenly to obtain a second solution; S3, transferring the second solution to an autoclave, reacting at 80-180°C for 6-24 hours, the pressure of the autoclave is 0.05-0.2MPa, and obtaining a third solution; S4, after cooling the third solution, adding an alkali metal auxiliary agent, stirring at room temperature for 6-12 hours, and then drying to obtain a sample; S5, reducing the sample at 500-550°C for 1.5-2h under an ammonia atmosphere to obtain a binuclear Ru-based ammonia cracking hydrogen production catalyst. The catalyst prepared in this application has a high ammonia conversion rate at low temperatures.

Description

Technical Field

[0001] The present application relates to the field of catalysts, and in particular, to a binuclear Ru-based ammonia cracking hydrogen production catalyst and a preparation method and application thereof. Background Art

[0002] Ammonia decomposition to produce hydrogen is a potential method for hydrogen production. With the growing demand for clean energy, hydrogen has attracted much attention as a clean and efficient energy source. Traditional hydrogen production methods have certain limitations. Ammonia has a high hydrogen content (17.65%) and is easy to store and transport. The ammonia decomposition process does not produce greenhouse gases. In the absence of a catalyst, the ammonia decomposition reaction requires a higher temperature (usually greater than 1000K) to proceed effectively, which not only consumes a lot of energy but also has high requirements for equipment. The presence of a catalyst can significantly reduce the activation energy of the reaction, allowing ammonia decomposition to proceed efficiently at a lower temperature. Therefore, the study of ammonia decomposition hydrogen production catalysts is crucial to improving hydrogen production efficiency and reducing hydrogen production costs.

[0003] Ammonia decomposition catalysts can be divided into two categories: transition metal catalysts and precious metal catalysts according to the different active components. Transition metals such as iron (Fe) and nickel (Ni) have been widely studied. Transition metal catalysts are relatively low in cost, and their catalytic activity can be improved by modifying them, such as loading them on a suitable carrier, but their performance is relatively poor; precious metal ruthenium (Ru)-based catalysts show high activity and can effectively catalyze ammonia decomposition reactions at relatively low temperatures (such as 500-600°C). Although many research advances have been made in catalytic activity and stability, existing ammonia decomposition catalysts for hydrogen production still cannot meet the demand.

[0004] In view of this, this application is hereby filed. Summary of the invention

[0005] The purpose of the present application is to provide a binuclear Ru-based ammonia decomposition hydrogen production catalyst and its preparation method and application, so as to solve the problem of insufficient catalytic activity and stability of existing ammonia decomposition hydrogen production catalysts.

[0006] In order to achieve the above-mentioned purpose of this application, the following technical solutions are specially adopted:

[0007] In a first aspect, the present application provides a method for preparing a binuclear Ru-based ammonia cracking hydrogen production catalyst, comprising the following steps:

[0008] S1, mixing the Ru metal precursor, the solvent and the ligand uniformly to obtain a first solution;

[0009] S2, adding a carrier to the first solution and mixing evenly to obtain a second solution;

[0010] S3, transferring the second solution to a high pressure reactor, reacting at 80-180° C. for 6-24 hours, with the pressure of the high pressure reactor being 0.05-0.2 MPa to obtain a third solution;

[0011] S4, after cooling the third solution, adding an alkali metal auxiliary agent, stirring at room temperature for 6-12 hours, and then drying to obtain a sample;

[0012] S5. Reduce the sample in an ammonia atmosphere at 500-550° C. for 1.5-2 h to obtain a binuclear Ru-based ammonia cracking catalyst for hydrogen production.

[0013] In some technical solutions, the Ru metal precursor includes ruthenium chloride and / or ruthenium nitrate.

[0014] In some technical schemes, the solvent includes at least one of acetone, tetrahydrofuran, acetonitrile, water or N,N-dimethylformamide.

[0015] In some technical schemes, the ligand includes at least one of 1,3-di(imidazolyl)butane, 1,3-di(imidazolylmethyl)benzene, 1,10-phenanthroline or 2,2'-bipyridine-4,4'-dicarboxylic acid.

[0016] In some technical solutions, the mixing method in S1 includes: first stirring to fully dissolve the raw materials, and then ultrasonicating for 20-40 minutes.

[0017] In some technical solutions, the drying method in S4 includes: drying at 60-110° C. for 10-14 hours.

[0018] In some technical solutions, the mass ratio of Ru metal precursor, ligand, alkali metal additive, solvent and carrier is (1%-10%): (1.2%-12%): (1%-20%): 4:1.

[0019] In some technical solutions, the mass ratio of Ru metal precursor, ligand, alkali metal additive, solvent and carrier is (3%-8%): (5%-10%): (5%-15%): 4:1.

[0020] In a second aspect, the present application provides a binuclear Ru-based ammonia cracking hydrogen production catalyst prepared by the above method.

[0021] In a third aspect, the present application provides an application of the above binuclear Ru-based ammonia cracking hydrogen production catalyst in ammonia cracking hydrogen production.

[0022] Compared with the prior art, the beneficial effects of this application are:

[0023] The preparation method of the binuclear Ru-based ammonia cracking hydrogen production catalyst provided in the present application uses Ru metal precursor, solvent, ligand, carrier, and alkali metal auxiliary as main raw materials, obtains a sample by step-by-step mixing and step-by-step reaction of the raw materials, and then reduces the sample at 500-550°C for 1.5-2h under an ammonia atmosphere to obtain the desired binuclear Ru-based ammonia cracking hydrogen production catalyst. The catalyst promotes the recombination of NN through the interaction between Ru-Ru, thereby further reducing the ammonia decomposition temperature. The NH3 conversion rate exceeds 90% under the conditions of 4800mL / g / h and 400°C, which is of great significance for promoting the development of ammonia decomposition hydrogen production technology and the application of hydrogen energy. DETAILED DESCRIPTION

[0024] The embodiments of the present application will be described in detail below in conjunction with the examples, but those skilled in the art will understand that the following examples are only used to illustrate the present application and should not be considered to limit the scope of the present application. If no specific conditions are specified in the examples, they are carried out according to conventional conditions or conditions recommended by the manufacturer.

[0025] In a first aspect, the present application provides a method for preparing a binuclear Ru-based ammonia cracking hydrogen production catalyst, comprising the following steps:

[0026] S1, mixing the Ru metal precursor, the solvent and the ligand uniformly to obtain a first solution;

[0027] S2, adding a carrier to the first solution and mixing evenly to obtain a second solution;

[0028] S3, transferring the second solution to a high pressure reactor, reacting at 80-180° C. for 6-24 hours, with the pressure of the high pressure reactor being 0.05-0.2 MPa to obtain a third solution;

[0029] S4, after cooling the third solution, adding an alkali metal auxiliary agent, stirring at room temperature for 6-12 hours, and then drying to obtain a sample;

[0030] S5. Reduce the sample in an ammonia atmosphere at 500-550° C. for 1.5-2 h to obtain a binuclear Ru-based ammonia cracking catalyst for hydrogen production.

[0031] The reaction in S3 can be carried out in a high pressure reactor. The room temperature in S4 is 20-25°C.

[0032] Optionally, the carrier includes at least one of carbon nanotubes, graphene, magnesium oxide, cerium oxide or aluminum oxide. The above carrier includes but is not limited to carbon nanotubes, graphene, magnesium oxide, cerium oxide, aluminum oxide, a combination of carbon nanotubes and graphene, a combination of magnesium oxide and cerium oxide, a combination of cerium oxide and aluminum oxide, a combination of carbon nanotubes, graphene and magnesium oxide, or a combination of magnesium oxide, cerium oxide and aluminum oxide, etc.

[0033] Optionally, the alkali metal additive includes at least one of a precursor of K, Na, Cs or Li. The alkali metal additive includes but is not limited to a precursor of K, a precursor of Na, a precursor of Cs, a precursor of Li, a precursor of K and Na, a precursor of Cs and Li, a precursor of K, Na, Cs, or a precursor of Na, Cs, Li, etc.

[0034] The above-mentioned binuclear Ru-based ammonia cracking hydrogen production catalyst preparation method uses Ru metal precursor, solvent, ligand, carrier, and alkali metal additive as main raw materials, and obtains a sample by step-by-step mixing and step-by-step reaction of the raw materials. The sample is then reduced at 500-550°C for 1.5-2h in an ammonia atmosphere to obtain the desired binuclear Ru-based ammonia cracking hydrogen production catalyst. The catalyst promotes the recombination of NN through the interaction between Ru-Ru, thereby further reducing the ammonia decomposition temperature. The NH3 conversion rate exceeds 90% under the conditions of 4800mL / g / h and 400°C, which is of great significance for promoting the development of ammonia decomposition hydrogen production technology and the application of hydrogen energy.

[0035] In an optional embodiment, the Ru metal precursor includes ruthenium chloride and / or ruthenium nitrate.

[0036] In an optional embodiment, the solvent includes at least one of acetone, tetrahydrofuran, acetonitrile, water or N,N-dimethylformamide. The above solvents include but are not limited to acetone, tetrahydrofuran, acetonitrile, water, N,N-dimethylformamide, a combination of acetone and tetrahydrofuran, a combination of acetonitrile and water, a combination of water and N,N-dimethylformamide, a combination of acetone, tetrahydrofuran and acetonitrile, a combination of acetonitrile, water and N,N-dimethylformamide, a combination of acetone, tetrahydrofuran, acetonitrile and water, or a combination of tetrahydrofuran, acetonitrile, water and N,N-dimethylformamide, etc.

[0037] In an optional embodiment, the ligand includes at least one of 1,3-di(imidazolyl)butane, 1,3-di(imidazolylmethyl)benzene, 1,10-phenanthroline or 2,2'-bipyridine-4,4'-dicarboxylic acid. The above-mentioned ligands include but are not limited to 1,3-di(imidazolyl)butane, 1,3-di(imidazolylmethyl)benzene, 1,10-phenanthroline, 2,2'-bipyridine-4,4'-dicarboxylic acid, a combination of 1,3-di(imidazolyl)butane and 1,3-di(imidazolylmethyl)benzene, a combination of 1,10-phenanthroline and 2,2'-bipyridine-4,4'-dicarboxylic acid, a combination of 1,3-di(imidazolyl)butane, 1,3-di(imidazolylmethyl)benzene and 1,10-phenanthroline, or a combination of 1,3-di(imidazolylmethyl)benzene, 1,10-phenanthroline and 2,2'-bipyridine-4,4'-dicarboxylic acid, etc.

[0038] In an optional embodiment, the mixing method in S1 includes: stirring to fully dissolve the raw materials, and then ultrasonicating for 20-40 minutes. The ultrasonic time is typically but not limited to 20 minutes, 22 minutes, 24 minutes, 26 minutes, 28 minutes, 30 minutes, 32 minutes, 34 minutes, 36 minutes, 38 minutes or 40 minutes. This embodiment can make the raw materials dispersed more evenly.

[0039] In an optional embodiment, the drying method in S4 includes: drying at 60-110°C for 10-14 hours. The above drying temperature is typically but not limited to 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C or 110°C. The above drying time is typically but not limited to 10 hours, 11 hours, 12 hours, 13 hours or 14 hours. This embodiment can effectively remove moisture from the solution.

[0040] In an optional embodiment, the mass ratio of Ru metal precursor, ligand, alkali metal auxiliary agent, solvent and carrier is (1%-10%): (1.2%-12%): (1%-20%): 4: 1. The above mass ratio is typically but not limited to 1%: 1.2%: 1%: 4: 1, 10%: 12%: 20%: 4: 1, 3%: 5%: 5%: 4: 1, 5%: 5%: 10%: 4: 1, 8%: 10%: 15%: 4: 1, 10%: 12%: 20%: 4: 1, 3%: 8%: 5%: 4: 1, 8%: 5%: 5%: 4: 1, or 5%: 10%: 15%: 4: 1, etc.

[0041] In an optional embodiment, the mass ratio of the Ru metal precursor, the ligand, the alkali metal additive, the solvent and the carrier is (3%-8%): (5%-10%): (5%-15%): 4:1.

[0042] The present application is further described in detail below with reference to embodiments and comparative examples.

[0043] Example 1

[0044] A method for preparing a binuclear Ru-based ammonia cracking hydrogen production catalyst comprises the following steps:

[0045] S1. Mix ruthenium trichloride, a solvent and a ligand uniformly to obtain a first solution; wherein the solvent is acetone, the ligand is 1,3-di(imidazolyl)butane, and the uniform mixing is stirring to fully dissolve the raw materials;

[0046] S2, adding a carrier to the first solution and mixing them evenly to obtain a second solution; wherein the carrier is carbon nanotubes;

[0047] S3, transferring the second solution to a high pressure reactor, reacting at 80° C. for 24 hours, the pressure of the high pressure reactor being 0.05 MPa to obtain a third solution;

[0048] S4, after cooling the third solution, adding an alkali metal auxiliary agent, stirring at room temperature for 12 hours, and then drying to obtain a sample; wherein the alkali metal auxiliary agent is potassium hydroxide;

[0049] The mass ratio of ruthenium trichloride, ligand, alkali metal auxiliary, solvent and carrier is 3%:5%:5%:4:1;

[0050] S5. Reduce the sample at 500° C. for 2 h in an ammonia atmosphere to obtain a binuclear Ru-based ammonia cracking catalyst for hydrogen production.

[0051] Example 2

[0052] A method for preparing a binuclear Ru-based ammonia cracking hydrogen production catalyst comprises the following steps:

[0053] S1. Mix ruthenium trichloride, a solvent and a ligand uniformly to obtain a first solution; wherein the solvent is acetone, the ligand is 1,3-di(imidazolyl)butane, and the uniform mixing is stirring to fully dissolve the raw materials;

[0054] S2, adding a carrier to the first solution and mixing them evenly to obtain a second solution; wherein the carrier is carbon nanotubes;

[0055] S3, transferring the second solution to a high pressure reactor, reacting at 180° C. for 6 hours at a pressure of 0.2 MPa to obtain a third solution;

[0056] S4, after cooling the third solution, adding an alkali metal auxiliary agent, stirring at room temperature for 6 hours, and then drying to obtain a sample; wherein the alkali metal auxiliary agent is potassium hydroxide;

[0057] The mass ratio of ruthenium trichloride, ligand, alkali metal auxiliary, solvent and carrier is 3%:5%:5%:4:1;

[0058] S5. Reduce the sample at 550° C. for 1.5 h under an ammonia atmosphere to obtain a binuclear Ru-based ammonia cracking catalyst for hydrogen production.

[0059] Example 3

[0060] A method for preparing a binuclear Ru-based ammonia cracking hydrogen production catalyst comprises the following steps:

[0061] S1. Mix ruthenium trichloride, a solvent and a ligand uniformly to obtain a first solution; wherein the solvent is acetone, the ligand is 1,3-di(imidazolyl)butane, and the uniform mixing is stirring to fully dissolve the raw materials;

[0062] S2, adding a carrier to the first solution, mixing evenly, to obtain a second solution; wherein the carrier is magnesium oxide;

[0063] S3, transferring the second solution to a high pressure reactor, reacting at 120° C. for 12 hours, the pressure of the high pressure reactor being 0.1 MPa to obtain a third solution;

[0064] S4, after cooling the third solution, adding an alkali metal auxiliary agent, stirring at room temperature for 8 hours, and then drying to obtain a sample; wherein the alkali metal auxiliary agent is potassium hydroxide;

[0065] The mass ratio of ruthenium trichloride, ligand, alkali metal auxiliary, solvent and carrier is 3%:5%:5%:4:1;

[0066] S5. Reduce the sample at 520° C. for 1.7 h under an ammonia atmosphere to obtain a binuclear Ru-based ammonia cracking catalyst for hydrogen production.

[0067] Example 3

[0068] A method for preparing a binuclear Ru-based ammonia cracking hydrogen production catalyst comprises the following steps:

[0069] S1. Mix ruthenium trichloride, a solvent and a ligand uniformly to obtain a first solution; wherein the solvent is acetone, the ligand is 1,3-di(imidazolyl)butane, and the uniform mixing is stirring to fully dissolve the raw materials;

[0070] S2, adding a carrier to the first solution and mixing them evenly to obtain a second solution; wherein the carrier is carbon nanotubes;

[0071] S3, transferring the second solution to a high pressure reactor, reacting at 80° C. for 24 hours, the pressure of the high pressure reactor being 0.05 MPa to obtain a third solution;

[0072] S4, after cooling the third solution, adding an alkali metal auxiliary agent, stirring at room temperature for 12 hours, and then drying to obtain a sample; wherein the alkali metal auxiliary agent is potassium hydroxide;

[0073] The mass ratio of ruthenium trichloride, ligand, alkali metal auxiliary, solvent and carrier is 3%:5%:5%:4:1;

[0074] S5. Reduce the sample at 500° C. for 2 h in an ammonia atmosphere to obtain a binuclear Ru-based ammonia cracking catalyst for hydrogen production.

[0075] Example 4

[0076] A method for preparing a binuclear Ru-based ammonia cracking hydrogen production catalyst comprises the following steps:

[0077] S1. Evenly mix ruthenium nitrate, a solvent and a ligand to obtain a first solution; wherein the solvent is acetone, the ligand is 1,3-di(imidazolyl)butane, and the even mixing is stirring to fully dissolve the raw materials;

[0078] S2, adding a carrier to the first solution and mixing them evenly to obtain a second solution; wherein the carrier is carbon nanotubes;

[0079] S3, transferring the second solution to a high pressure reactor, reacting at 80° C. for 24 hours, the pressure of the high pressure reactor being 0.05 MPa to obtain a third solution;

[0080] S4, after cooling the third solution, adding an alkali metal auxiliary agent, stirring at room temperature for 12 hours, and then drying to obtain a sample; wherein the alkali metal auxiliary agent is potassium hydroxide;

[0081] The mass ratio of ruthenium nitrate, ligand, alkali metal auxiliary, solvent and carrier is 3%:5%:5%:4:1;

[0082] S5. Reduce the sample at 500° C. for 2 h in an ammonia atmosphere to obtain a binuclear Ru-based ammonia cracking catalyst for hydrogen production.

[0083] Different from Example 3, this example uses ruthenium nitrate.

[0084] Example 5

[0085] A method for preparing a binuclear Ru-based ammonia cracking hydrogen production catalyst comprises the following steps:

[0086] S1. Evenly mix ruthenium trichloride, a solvent and a ligand to obtain a first solution; wherein the solvent is tetrahydrofuran and acetonitrile, and the ligand is 1,10-phenanthroline and 2,2'-bipyridine-4,4'-dicarboxylic acid, and the even mixing is stirring to fully dissolve the raw materials;

[0087] S2, adding a carrier to the first solution and mixing them evenly to obtain a second solution; wherein the carrier is carbon nanotubes;

[0088] S3, transferring the second solution to a high pressure reactor, reacting at 80° C. for 24 hours, the pressure of the high pressure reactor being 0.05 MPa to obtain a third solution;

[0089] S4, after cooling the third solution, adding an alkali metal auxiliary agent, stirring at room temperature for 12 hours, and then drying to obtain a sample; wherein the alkali metal auxiliary agent is potassium hydroxide;

[0090] The mass ratio of ruthenium trichloride, ligand, alkali metal auxiliary, solvent and carrier is 3%:5%:5%:4:1;

[0091] S5. Reduce the sample at 500° C. for 2 h in an ammonia atmosphere to obtain a binuclear Ru-based ammonia cracking catalyst for hydrogen production.

[0092] Different from Example 3, the solvents used in this example are tetrahydrofuran and acetonitrile, and the ligands used are 1,10-phenanthroline and 2,2'-bipyridine-4,4'-dicarboxylic acid. The mass ratio of tetrahydrofuran to acetonitrile is 1.1:1; the mass ratio of 1,10-phenanthroline to 2,2'-bipyridine-4,4'-dicarboxylic acid is 1:1.

[0093] Example 6

[0094] A method for preparing a binuclear Ru-based ammonia cracking hydrogen production catalyst comprises the following steps:

[0095] S1. Mix ruthenium trichloride, a solvent and a ligand uniformly to obtain a first solution; wherein the solvent is water, the ligand is 1,3-di(imidazolyl)butane, and the uniform mixing is stirring to fully dissolve the raw materials;

[0096] S2, adding a carrier to the first solution and mixing them evenly to obtain a second solution; wherein the carrier is carbon nanotubes;

[0097] S3, transferring the second solution to a high pressure reactor, reacting at 80° C. for 24 hours, the pressure of the high pressure reactor being 0.05 MPa to obtain a third solution;

[0098] S4, after cooling the third solution, adding an alkali metal auxiliary agent, stirring at room temperature for 12 hours, and then drying to obtain a sample; wherein the alkali metal auxiliary agent is potassium hydroxide;

[0099] The mass ratio of ruthenium trichloride, ligand, alkali metal auxiliary, solvent and carrier is 3%:5%:5%:4:1;

[0100] S5. Reduce the sample at 500° C. for 2 h in an ammonia atmosphere to obtain a binuclear Ru-based ammonia cracking catalyst for hydrogen production.

[0101] Different from Example 3, water is used as the solvent in this example.

[0102] Example 7

[0103] A method for preparing a binuclear Ru-based ammonia cracking hydrogen production catalyst comprises the following steps:

[0104] S1. Mix ruthenium trichloride, a solvent and a ligand uniformly to obtain a first solution; wherein the solvent is N,N-dimethylformamide, the ligand is 1,3-di(imidazolemethyl)benzene, and the uniform mixing is stirring to fully dissolve the raw materials;

[0105] S2, adding a carrier to the first solution and mixing them evenly to obtain a second solution; wherein the carrier is carbon nanotubes;

[0106] S3, transferring the second solution to a high pressure reactor, reacting at 80° C. for 24 hours, the pressure of the high pressure reactor being 0.05 MPa to obtain a third solution;

[0107] S4, after cooling the third solution, adding an alkali metal auxiliary agent, stirring at room temperature for 12 hours, and then drying to obtain a sample; wherein the alkali metal auxiliary agent is potassium hydroxide;

[0108] The mass ratio of ruthenium trichloride, ligand, alkali metal auxiliary, solvent and carrier is 3%:5%:5%:4:1;

[0109] S5. Reduce the sample at 500° C. for 2 h in an ammonia atmosphere to obtain a binuclear Ru-based ammonia cracking catalyst for hydrogen production.

[0110] Different from Example 3, the solvent of this example is N,N-dimethylformamide, and the ligand is 1,3-di(imidazolemethyl)benzene.

[0111] Example 8

[0112] A method for preparing a binuclear Ru-based ammonia cracking hydrogen production catalyst comprises the following steps:

[0113] S1, mixing ruthenium trichloride, a solvent and a ligand uniformly to obtain a first solution; wherein the solvent is N,N-dimethylformamide, and the ligand is 1,3-di(imidazolemethyl)benzene, and the uniform mixing includes first stirring to fully dissolve the raw materials, and then ultrasonicating for 30 minutes;

[0114] S2, adding a carrier to the first solution and mixing them evenly to obtain a second solution; wherein the carrier is carbon nanotubes;

[0115] S3, transferring the second solution to a high pressure reactor, reacting at 80° C. for 24 hours, the pressure of the high pressure reactor being 0.05 MPa to obtain a third solution;

[0116] S4, after cooling the third solution, adding an alkali metal auxiliary agent, stirring at room temperature for 12 hours, and then drying to obtain a sample; wherein the alkali metal auxiliary agent is potassium hydroxide;

[0117] The mass ratio of ruthenium trichloride, ligand, alkali metal auxiliary, solvent and carrier is 3%:5%:5%:4:1;

[0118] S5. Reduce the sample at 500° C. for 2 h in an ammonia atmosphere to obtain a binuclear Ru-based ammonia cracking catalyst for hydrogen production.

[0119] Different from Example 7, this example adopts a specific mixing method.

[0120] Example 9

[0121] A method for preparing a binuclear Ru-based ammonia cracking hydrogen production catalyst comprises the following steps:

[0122] S1, mixing ruthenium trichloride, a solvent and a ligand uniformly to obtain a first solution; wherein the solvent is N,N-dimethylformamide, and the ligand is 1,3-di(imidazolemethyl)benzene, and the uniform mixing includes first stirring to fully dissolve the raw materials, and then ultrasonicating for 30 minutes;

[0123] S2, adding a carrier to the first solution and mixing them evenly to obtain a second solution; wherein the carrier is carbon nanotubes;

[0124] S3, transferring the second solution to a high pressure reactor, reacting at 80° C. for 24 hours, the pressure of the high pressure reactor being 0.05 MPa to obtain a third solution;

[0125] S4, after cooling the third solution, adding an alkali metal auxiliary agent, stirring at room temperature for 12 hours, and then drying to obtain a sample; wherein the alkali metal auxiliary agent is potassium hydroxide; the drying method includes: drying at 80° C. for 12 hours;

[0126] The mass ratio of ruthenium trichloride, ligand, alkali metal auxiliary, solvent and carrier is 3%:5%:5%:4:1;

[0127] S5. Reduce the sample at 500° C. for 2 h in an ammonia atmosphere to obtain a binuclear Ru-based ammonia cracking catalyst for hydrogen production.

[0128] Different from Example 8, this example adopts a specific drying method.

[0129] Examples 10-14

[0130] A method for preparing a binuclear Ru-based ammonia cracking hydrogen production catalyst, which is different from Example 8 in that the mass ratios of ruthenium trichloride, ligand, alkali metal additive, solvent and carrier in this embodiment are: 8%:10%:15%:4:1, 5%:8%:10%:4:1, 1%:1.2%:1%:4:1, 10%:12%:20%:4:1, 12%:15%:0.5%:4:1, and the remaining steps and parameters are the same as those in Example 8.

[0131] The mass ratio of ruthenium trichloride, ligand, alkali metal auxiliary, solvent and carrier in Examples 12-13 is within the preferred range of the present application, the mass ratio of ruthenium trichloride, ligand, alkali metal auxiliary, solvent and carrier in Examples 9-11 is within the further preferred range of the present application, and the mass ratio of ruthenium trichloride, ligand, alkali metal auxiliary, solvent and carrier in Example 14 is not within the preferred range of the present application.

[0132] Comparative Example 1

[0133] A method for preparing a binuclear Ru-based ammonia cracking hydrogen production catalyst comprises the following steps:

[0134] S1. Mix ruthenium trichloride, a solvent and a ligand uniformly to obtain a first solution; wherein the solvent is acetone, the ligand is 1,3-di(imidazolyl)butane, and the uniform mixing is stirring to fully dissolve the raw materials;

[0135] S2, adding a carrier to the first solution and mixing them evenly to obtain a second solution; wherein the carrier is carbon nanotubes;

[0136] S3, transferring the second solution to a high pressure reactor, reacting at 70° C. for 25 hours, the pressure of the high pressure reactor being 0.05 MPa to obtain a third solution;

[0137] S4, after cooling the third solution, adding an alkali metal auxiliary agent, stirring at room temperature for 12 hours, and then drying to obtain a sample; wherein the alkali metal auxiliary agent is potassium hydroxide;

[0138] The mass ratio of ruthenium trichloride, ligand, alkali metal auxiliary, solvent and carrier is 3%:5%:5%:4:1;

[0139] S5. Reduce the sample at 500° C. for 2 h in an ammonia atmosphere to obtain a binuclear Ru-based ammonia cracking catalyst for hydrogen production.

[0140] Different from Example 1, the reaction temperature and reaction time in Comparative Example S3 are not within the range provided by the present invention.

[0141] Comparative Example 2

[0142] A method for preparing a binuclear Ru-based ammonia cracking hydrogen production catalyst comprises the following steps:

[0143] S1. Mix ruthenium trichloride, a solvent and a ligand uniformly to obtain a first solution; wherein the solvent is acetone, the ligand is 1,3-di(imidazolyl)butane, and the uniform mixing is stirring to fully dissolve the raw materials;

[0144] S2, adding a carrier to the first solution and mixing them evenly to obtain a second solution; wherein the carrier is carbon nanotubes;

[0145] S3, transferring the second solution to a high pressure reactor, reacting at 80° C. for 24 hours, the pressure of the high pressure reactor being 0.3 MPa to obtain a third solution;

[0146] S4, after cooling the third solution, adding an alkali metal auxiliary agent, stirring at room temperature for 12 hours, and then drying to obtain a sample; wherein the alkali metal auxiliary agent is potassium hydroxide;

[0147] The mass ratio of ruthenium trichloride, ligand, alkali metal auxiliary, solvent and carrier is 3%:5%:5%:4:1;

[0148] S5. Reduce the sample at 500° C. for 2 h in an ammonia atmosphere to obtain a binuclear Ru-based ammonia cracking catalyst for hydrogen production.

[0149] Different from Example 1, the pressure of the high-pressure reactor in Comparative Example S3 is not within the range provided by the invention.

[0150] Comparative Example 3

[0151] A method for preparing a binuclear Ru-based ammonia cracking hydrogen production catalyst comprises the following steps:

[0152] S1. Mix ruthenium trichloride, a solvent and a ligand uniformly to obtain a first solution; wherein the solvent is acetone, the ligand is 1,3-di(imidazolyl)butane, and the uniform mixing is stirring to fully dissolve the raw materials;

[0153] S2, adding a carrier to the first solution and mixing them evenly to obtain a second solution; wherein the carrier is carbon nanotubes;

[0154] S3, transferring the second solution to a high pressure reactor, reacting at 80° C. for 24 hours, the pressure of the high pressure reactor being 0.05 MPa to obtain a third solution;

[0155] S4, after cooling the third solution, adding an alkali metal auxiliary agent, stirring at room temperature for 5 hours, and then drying to obtain a sample; wherein the alkali metal auxiliary agent is potassium hydroxide;

[0156] The mass ratio of ruthenium trichloride, ligand, alkali metal auxiliary, solvent and carrier is 3%:5%:5%:4:1;

[0157] S5. Reduce the sample at 500° C. for 2 h in an ammonia atmosphere to obtain a binuclear Ru-based ammonia cracking catalyst for hydrogen production.

[0158] Different from Example 1, the stirring time in Comparative Example S4 is not within the range provided by the invention.

[0159] Comparative Example 4

[0160] A method for preparing a binuclear Ru-based ammonia cracking hydrogen production catalyst comprises the following steps:

[0161] S1. Mix ruthenium trichloride, a solvent and a ligand uniformly to obtain a first solution; wherein the solvent is acetone, the ligand is 1,3-di(imidazolyl)butane, and the uniform mixing is stirring to fully dissolve the raw materials;

[0162] S2, adding a carrier to the first solution and mixing them evenly to obtain a second solution; wherein the carrier is carbon nanotubes;

[0163] S3, transferring the second solution to a high pressure reactor, reacting at 80° C. for 24 hours, the pressure of the high pressure reactor being 0.05 MPa to obtain a third solution;

[0164] S4, after cooling the third solution, adding an alkali metal auxiliary agent, stirring at room temperature for 6 hours, and then drying to obtain a sample; wherein the alkali metal auxiliary agent is potassium hydroxide;

[0165] The mass ratio of ruthenium trichloride, ligand, alkali metal auxiliary, solvent and carrier is 3%:5%:5%:4:1;

[0166] S5. Reduce the sample at 480° C. for 2.5 h under an ammonia atmosphere to obtain a binuclear Ru-based ammonia cracking catalyst for hydrogen production.

[0167] Different from Example 1, the reaction time and reaction temperature in this comparative example S5 are not within the range provided by the invention.

[0168] Comparative Example 5

[0169] A method for preparing a binuclear Ru-based ammonia cracking hydrogen production catalyst comprises the following steps:

[0170] S1. Mix ruthenium trichloride, a solvent, a ligand and a carrier uniformly to obtain a first solution; wherein the solvent is acetone, the ligand is 1,3-di(imidazolyl)butane, and the carrier is a carbon nanotube; the uniform mixing is stirring to fully dissolve each raw material;

[0171] S2, transferring the first solution to a high pressure reactor, reacting at 80° C. for 24 hours, the pressure of the high pressure reactor being 0.05 MPa to obtain a second solution;

[0172] S3, after cooling the second solution, adding an alkali metal auxiliary agent, stirring at room temperature for 12 hours, and then drying to obtain a sample; wherein the alkali metal auxiliary agent is potassium hydroxide;

[0173] The mass ratio of ruthenium trichloride, ligand, alkali metal auxiliary, solvent and carrier is 3%:5%:5%:4:1;

[0174] S4. Reduce the sample at 500° C. for 2 h in an ammonia atmosphere to obtain a binuclear Ru-based ammonia cracking catalyst for hydrogen production.

[0175] Different from Example 1, in this comparative example, ruthenium trichloride, solvent, ligand and carrier are directly mixed evenly instead of being mixed in steps.

[0176] Comparative Example 6

[0177] A method for preparing a binuclear Ru-based ammonia cracking hydrogen production catalyst comprises the following steps:

[0178] S1. Mix ruthenium trichloride, a solvent and a ligand uniformly to obtain a first solution; wherein the solvent is acetone, the ligand is 1,3-di(imidazolyl)butane, and the uniform mixing is stirring to fully dissolve the raw materials;

[0179] S2, adding a carrier to the first solution and mixing them evenly to obtain a second solution; wherein the carrier is carbon nanotubes;

[0180] The mass ratio of ruthenium trichloride, ligand, solvent and carrier is 3%:5%:4:1;

[0181] S3, transferring the second solution to a high pressure reactor, reacting at 80° C. for 24 hours, the pressure of the high pressure reactor being 0.05 MPa to obtain a third solution;

[0182] S4, cooling the third solution, and drying it to obtain a sample;

[0183] S5. Reduce the sample at 500° C. for 2 h in an ammonia atmosphere to obtain a binuclear Ru-based ammonia cracking catalyst for hydrogen production.

[0184] Different from Example 1, no alkali metal auxiliary agent was added in Comparative Example S4.

[0185] Comparative Example 7

[0186] A method for preparing a binuclear Ru-based ammonia cracking hydrogen production catalyst comprises the following steps:

[0187] S1. Mixing ruthenium trichloride and a solvent uniformly to obtain a first solution; wherein the solvent is acetone, and the uniform mixing is stirring to fully dissolve the raw materials;

[0188] S2, adding a carrier to the first solution and mixing them evenly to obtain a second solution; wherein the carrier is carbon nanotubes;

[0189] S3, transferring the second solution to a high pressure reactor, reacting at 80° C. for 24 hours, the pressure of the high pressure reactor being 0.05 MPa to obtain a third solution;

[0190] S4, after cooling the third solution, adding an alkali metal auxiliary agent, stirring at room temperature for 12 hours, and then drying to obtain a sample; wherein the alkali metal auxiliary agent is potassium hydroxide;

[0191] The mass ratio of ruthenium trichloride, alkali metal auxiliary agent, solvent and carrier is 3%:5%:4:1;

[0192] S5. Reduce the sample at 500° C. for 2 h in an ammonia atmosphere to obtain a binuclear Ru-based ammonia cracking catalyst for hydrogen production.

[0193] Different from the examples, no ligand was added in Comparative Example S1.

[0194] Comparative Example 8

[0195] A method for preparing a catalyst for hydrogen production by cracking ammonia comprises the following steps:

[0196] S1. Mix ruthenium trichloride, cobalt nitrate, a solvent and a ligand uniformly to obtain a first solution; wherein the solvent is acetone, the ligand is 1,3-di(imidazolyl)butane, and the uniform mixing is stirring to fully dissolve the raw materials;

[0197] S2, adding a carrier to the first solution and mixing them evenly to obtain a second solution; wherein the carrier is carbon nanotubes;

[0198] S3, transferring the second solution to a high pressure reactor, reacting at 80° C. for 24 hours, the pressure of the high pressure reactor being 0.05 MPa to obtain a third solution;

[0199] S4, after cooling the third solution, adding an alkali metal auxiliary agent, stirring at room temperature for 12 hours, and then drying to obtain a sample; wherein the alkali metal auxiliary agent is potassium hydroxide;

[0200] The mass ratio of ruthenium trichloride, cobalt nitrate, ligand, alkali metal auxiliary, solvent and carrier is 1.5%:1.5%:5%:5%:4:1;

[0201] S5. Reduce the sample under an ammonia atmosphere at 500° C. for 2 h to obtain an ammonia cracking catalyst for hydrogen production.

[0202] Different from Example 1, cobalt nitrate was added in Comparative Example S1.

[0203] Comparative Example 9

[0204] A method for preparing a catalyst for hydrogen production by cracking ammonia comprises the following steps:

[0205] S1. Mix ruthenium trichloride, gold chloride and a ligand uniformly to obtain a first solution; wherein the solvent is acetone, the ligand is 1,3-di(imidazolyl)butane, and the uniform mixing is stirring to fully dissolve the raw materials;

[0206] S2, adding a carrier to the first solution and mixing them evenly to obtain a second solution; wherein the carrier is carbon nanotubes;

[0207] S3, transferring the second solution to a high pressure reactor, reacting at 80° C. for 24 hours, the pressure of the high pressure reactor being 0.05 MPa to obtain a third solution;

[0208] S4, after cooling the third solution, adding an alkali metal auxiliary agent, stirring at room temperature for 12 hours, and then drying to obtain a sample; wherein the alkali metal auxiliary agent is potassium hydroxide;

[0209] The mass ratio of ruthenium trichloride, gold cobalt chloride, ligand, alkali metal auxiliary, solvent and carrier is 1.5%:1.5%:5%:5%:4:1;

[0210] S5. Reduce the sample under an ammonia atmosphere at 500° C. for 2 h to obtain an ammonia cracking catalyst for hydrogen production.

[0211] Different from Example 1, gold chloride is added in this comparative example S1.

[0212] Comparative Example 10

[0213] A method for preparing a catalyst for hydrogen production by cracking ammonia comprises the following steps:

[0214] S1. Evenly mix ruthenium trichloride, copper chloride, a solvent and a ligand to obtain a first solution; wherein the solvent is acetone, the ligand is 1,3-di(imidazolyl)butane, and the even mixing is stirring to fully dissolve the raw materials;

[0215] S2, adding a carrier to the first solution and mixing them evenly to obtain a second solution; wherein the carrier is carbon nanotubes;

[0216] S3, transferring the second solution to a high pressure reactor, reacting at 80° C. for 24 hours, the pressure of the high pressure reactor being 0.05 MPa to obtain a third solution;

[0217] S4, after cooling the third solution, adding an alkali metal auxiliary agent, stirring at room temperature for 12 hours, and then drying to obtain a sample; wherein the alkali metal auxiliary agent is potassium hydroxide;

[0218] The mass ratio of ruthenium trichloride, cupric chloride, ligand, alkali metal auxiliary, solvent and carrier is 1.5%:1.5%:5%:5%:4:1;

[0219] S5. Reduce the sample under an ammonia atmosphere at 500° C. for 2 h to obtain an ammonia cracking catalyst for hydrogen production.

[0220] Different from Example 1, copper chloride is added in this comparative example S1.

[0221] Comparative Example 11

[0222] A method for preparing a catalyst for hydrogen production by cracking ammonia comprises the following steps:

[0223] S1. Mix ruthenium trichloride, rhodium chloride, a solvent and a ligand uniformly to obtain a first solution; wherein the solvent is acetone, the ligand is 1,3-di(imidazolyl)butane, and the uniform mixing is stirring to fully dissolve the raw materials;

[0224] S2, adding a carrier to the first solution and mixing them evenly to obtain a second solution; wherein the carrier is carbon nanotubes;

[0225] S3, transferring the second solution to a high pressure reactor, reacting at 80° C. for 24 hours, the pressure of the high pressure reactor being 0.05 MPa to obtain a third solution;

[0226] S4, after cooling the third solution, adding an alkali metal auxiliary agent, stirring at room temperature for 12 hours, and then drying to obtain a sample; wherein the alkali metal auxiliary agent is potassium hydroxide;

[0227] The mass ratio of ruthenium trichloride, rhodium chloride, ligand, alkali metal auxiliary, solvent and carrier is 1.5%:1.5%:5%:5%:4:1;

[0228] S5. Reduce the sample under an ammonia atmosphere at 500° C. for 2 h to obtain an ammonia cracking catalyst for hydrogen production.

[0229] Different from Example 1, rhodium chloride was added in this comparative example S1.

[0230] The NH3 conversion rate of the catalyst in the above embodiments and comparative examples under the conditions of 4800ml / g / h and 400°C was tested in the following method: 1g (40-60 mesh) of the catalyst was placed in a reaction tube; then 80ml / min of ammonia was introduced into the bypass, and the value of ammonia in the tail gas was recorded; ammonia was introduced into the reaction tube and the temperature was raised to 400°C at a rate of 10°C / min and maintained at this temperature for 30min and the value was recorded. The test results are shown in Table 1.

[0231] Table 1

[0232]

[0233] Although the present application has been illustrated and described with specific embodiments, it will be appreciated that many other changes and modifications may be made without departing from the spirit and scope of the present application. Therefore, it is intended that all such changes and modifications within the scope of the present application be included in the appended claims.

Claims

1. A method for preparing a binuclear Ru-based ammonia cracking hydrogen production catalyst, characterized in that: The following steps are involved: S1. Evenly mix a Ru metal precursor, a solvent and a ligand to obtain a first solution; the ligand comprises at least one of 1,3-di(imidazolyl)butane, 1,3-di(imidazolylmethyl)benzene, 1,10-phenanthroline or 2,2'-bipyridine-4,4'-dicarboxylic acid; S2, adding a carrier to the first solution and mixing evenly to obtain a second solution; S3, transferring the second solution to a high pressure reactor, reacting at 80-180° C. for 6-24 hours, with the pressure of the high pressure reactor being 0.05-0.2 MPa to obtain a third solution; S4, after cooling the third solution, adding an alkali metal auxiliary agent, stirring at room temperature for 6-12 hours, and then drying to obtain a sample; S5. Reduce the sample in an ammonia atmosphere at 500-550° C. for 1.5-2 h to obtain a binuclear Ru-based ammonia cracking catalyst for hydrogen production.

2. The method for preparing a binuclear Ru-based ammonia cracking hydrogen production catalyst according to claim 1, characterized in that: The Ru metal precursor includes ruthenium chloride and / or ruthenium nitrate.

3. The method for preparing a binuclear Ru-based ammonia cracking hydrogen production catalyst according to claim 1, characterized in that: The solvent includes at least one of acetone, tetrahydrofuran, acetonitrile, water or N,N-dimethylformamide.

4. The method for preparing a binuclear Ru-based ammonia cracking hydrogen production catalyst according to claim 1, characterized in that: The mixing method in S1 includes: first stirring to fully dissolve the raw materials, and then ultrasonicating for 20-40 minutes.

5. The method for preparing a binuclear Ru-based ammonia cracking hydrogen production catalyst according to claim 1, characterized in that: The drying method in S4 includes: drying at 60-110° C. for 10-14 hours.

6. The method for preparing a binuclear Ru-based ammonia cracking hydrogen production catalyst according to claim 1, characterized in that: The mass ratio of Ru metal precursor, ligand, alkali metal additive, solvent and carrier is (1%-10%): (1.2%-12%): (1%-20%): 4:

1.

7. The method for preparing a binuclear Ru-based ammonia cracking hydrogen production catalyst according to claim 6, characterized in that: The mass ratio of Ru metal precursor, ligand, alkali metal additive, solvent and carrier is (3%-8%): (5%-10%): (5%-15%): 4:

1.

8. A binuclear Ru-based ammonia cracking hydrogen production catalyst, characterized in that: The method is prepared by any one of claims 1 to 7.

9. Use of the binuclear Ru-based ammonia cracking hydrogen production catalyst according to claim 8 in ammonia cracking hydrogen production.

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