Preparation method of catalyst, catalyst and application of catalyst

Abstract

The invention provides a preparation method of a catalyst, the catalyst and application of the catalyst, and relates to the technical field of catalysts.The preparation method of the catalyst comprises the following steps that gamma-Al2O3 is crushed; mixing a gamma-Al2O3 crushed material obtained by crushing with an auxiliary active component precursor solution, and sequentially dipping, drying and calcining to obtain a catalyst precursor I; mixing the catalyst precursor I with the active component precursor solution, and sequentially dipping, drying and calcining to obtain a catalyst precursor II; and carrying out temperature programming reduction on the catalyst precursor II in an argon-hydrogen atmosphere to obtain the catalyst. The catalyst prepared by the preparation method of the catalyst provided by the invention has longer catalytic life. By adding the auxiliary active component, the catalytic life of the catalyst can be remarkably prolonged, and hydrogen storage of N-heterocyclic aromatic hydrocarbon in a continuous flow fixed bed reactor for a longer time is facilitated. And meanwhile, the production efficiency is improved, the manufacturing cost is reduced, and the economic benefit of hydrogen storage is better.

Description

Technical Field

[0001] The present invention relates to the technical field of catalysts, and in particular to a method for preparing a catalyst, a catalyst and applications thereof. Background Art

[0002] At present, in the relevant technologies of hydrogen storage, the use of N-heterocyclic aromatic hydrocarbons (N-HAR) organic liquids for hydrogen storage is a liquid hydrogen storage technology based on organic compounds. This technology uses N-heterocyclic aromatic hydrocarbon compounds to react with hydrogen to form hydrides, thereby realizing the storage and release of hydrogen. At present, in the relevant technologies of N-heterocyclic aromatic hydrocarbon hydrogen storage based on fixed bed reactors, catalysts are one of the key influencing factors, which have an important influence on the reaction rate and reaction reversibility.

[0003] However, since the catalyst is used under high temperature and high pressure in the N-heteroaromatic hydrogen storage process based on a fixed bed reactor, the existing catalyst is prone to structural changes or loss of active ingredients during long-term use, resulting in a decrease in catalytic performance and, in turn, low catalytic efficiency. Summary of the invention

[0004] In order to solve the technical problems in the related art, the present invention provides a method for preparing a catalyst, a catalyst and application thereof.

[0005] In order to achieve the above object, the technical solution adopted by the present invention includes:

[0006] According to a first aspect of the present invention, there is provided a method for preparing a catalyst, comprising the following steps:

[0007] Step S1: crushing γ-Al2O3;

[0008] Step S2: mixing the crushed γ-Al2O3 material obtained in step S1 with the precursor solution of the auxiliary active component, and sequentially performing impregnation, drying and calcination to obtain a catalyst precursor I;

[0009] Step S3: mixing the catalyst precursor I with the active component precursor solution, and sequentially performing impregnation, drying and calcination to obtain the catalyst precursor II;

[0010] Step S4: subjecting the catalyst precursor II to programmed temperature reduction in an argon-hydrogen atmosphere to obtain a catalyst.

[0011] Optionally, in step S1, the particle size of γ-Al2O3 is 2 mm-4 mm.

[0012] Optionally, in step S1, γ-Al2O3 is crushed into 20-40 meshes.

[0013] Optionally, the co-active component is one or more of potassium, sodium and magnesium.

[0014] Optionally, the active component is one or more of ruthenium, nickel, rhodium and palladium.

[0015] According to the second aspect of the present invention, there is also provided a catalyst, which is prepared by the preparation method as described in any one of the technical solutions in the first aspect of the present invention; and / or, the components of the catalyst include an active component, a co-active component and a carrier, wherein the co-active component is one or more of potassium, sodium and magnesium, the active component is one or more of ruthenium, nickel, rhodium and palladium, and the carrier is γ-Al2O3.

[0016] Optionally, the content of the active component is 1wt%-5wt%.

[0017] Optionally, the content of the co-active component is 1 wt%-10 wt%.

[0018] According to a third aspect of the present invention, there is also provided an application of the catalyst described in any one of the technical solutions in the second aspect of the present invention for hydrogen storage in a fixed bed reactor;

[0019] Optionally, the specific steps include:

[0020] The catalyst is loaded into a fixed bed reactor, the H2 pressure is between 0.1MPa-7MPa, the H2 flow rate is between 1mL / min-90mL / min, the N-heterocyclic aromatic hydrocarbon flow rate is between 0.01mL / min-3mL / min, and the reaction temperature is between 90℃-150℃.

[0021] Beneficial effects:

[0022] 1. First, the catalyst prepared by the method for preparing the catalyst of the present invention has a longer catalytic life. Specifically, the addition of the co-active component of the present invention can significantly increase the catalytic life of the catalyst, which is conducive to the longer storage of hydrogen of N-heterocyclic aromatic hydrocarbons in a continuous flow fixed bed reactor. In this way, it is also possible to effectively delay the time for the catalyst to undergo structural changes or the loss of active ingredients, which is conducive to ensuring the catalytic performance of the catalyst for a relatively longer period of time, thereby effectively improving the catalytic efficiency.

[0023] Second, the co-active component of the present invention is a cheap alkali metal component, which can significantly increase the catalytic life of the catalyst while also helping to improve production efficiency and reduce manufacturing costs, thereby making hydrogen storage more economically beneficial.

[0024] Third, the addition of potassium as an active ingredient can significantly increase the life of the catalyst. It should be noted that after adding 4wt% of potassium, the life of the catalyst can be extended from 16h to 31h compared to the catalyst without potassium (at the same time, the hydrogen storage density is ensured to be greater than or equal to 5.0wt%).

[0025] 2. Other beneficial effects or advantages of the present invention will be described in detail in the specific implementation manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative labor.

[0027] in:

[0028] Figure 1 is a schematic flow chart of steps of a method for preparing a catalyst provided by an exemplary embodiment of the present invention;

[0029] Figure 2 3 is a schematic diagram comparing the changes in hydrogen storage density of the catalysts of Examples 1-3 and Comparative Examples 1-3 of the present invention during the continuous hydrogen storage process in a fixed bed reactor, wherein in Examples 1-3 and Comparative Examples 1-3, the reaction conditions are that the flow rate of N-methylindole is 0.1 mL / min, the hydrogen pressure and its flow rate are 5 MPa, 90 mL / min, and the reaction temperature is 130°C. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0031] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] The technical solution of the present invention is described in detail below in conjunction with the accompanying drawings, embodiments and comparative examples.

[0033] Example 1 (Preparation of Ru5K2 / γ-Al2O3 Catalyst and Catalytic N-Methylindole Hydrogen Storage. In this example, Ru5K2 refers to 5% by mass of Ru and 2% by mass of K)

[0034] Preparation of catalyst precursor I: Dry 5 g of γ-Al2O3 carrier at 300°C for 12 h, cool to room temperature, dissolve 191 mg of KCl in 5 mL of deionized water to form a KCl solution. Use a dropper to slowly add the KCl solution dropwise to the γ-Al2O3 carrier, seal with plastic wrap after the addition is complete, place in a cool and dry place for 12 h, move to a 60°C oven and slowly dry for 12 h. After drying, move to a tubular furnace and calcine at 300°C for 2 h under a nitrogen atmosphere to obtain catalyst precursor I.

[0035] Preparation of catalyst precursor II: Dissolve 530 mg of RuCl3 in 5 mL of deionized water and treat with ultrasound for 10 min to form a uniform RuCl3 solution. Use a dropper to slowly add the RuCl3 solution drop by drop into catalyst precursor I. After the addition is complete, seal it with plastic wrap, place it in a cool and dry place for 12 hours, move it to a 60°C oven and slowly dry it for 12 hours. After drying, move it into a tubular furnace and calcine it at 450°C for 4 hours under a nitrogen atmosphere to obtain catalyst precursor II.

[0036] Preparation of Ru5K2 / γ-Al2O3 catalyst. 5 g of the above catalyst precursor II was transferred into a tube furnace, and 5% hydrogen-argon gas (i.e., a mixed gas of 5% hydrogen + 95% argon) was introduced at a flow rate of 100 mL / min. The temperature was raised to 450°C at a rate of 5°C / min and maintained at 450°C for 4 h to complete the reduction of the catalyst precursor II and obtain the Ru5K2 / γ-Al2O3 catalyst.

[0037] Ru5K2 / γ-Al2O3 catalyst continuously stores hydrogen in a fixed bed reactor. 2 g of the catalyst is loaded into the constant temperature zone of the fixed bed reaction tube. Before the reaction starts, nitrogen is replaced for 3 minutes. After the nitrogen replacement is completed, 1 MPa pressure hydrogen is replaced for 3 minutes. After the hydrogen replacement is completed, the hydrogen pressure is increased to 5 MPa. After the pressure increase is completed, the preheater and reaction column temperature are set to 130°C. After the temperature stabilizes, N-methylindole is pumped into the reactor at a flow rate of 0.1 mL / min, and the hydrogen flow rate is 90 mL / min. After the reaction system is stabilized, the liquid product from the liquid port is taken out at regular intervals and quantitatively analyzed by gas chromatograph. For the hydrogen storage density of the catalyst, please refer to Figure 2 .

[0038] Example 2 (Preparation of Ru5K4 / γ-Al2O3 Catalyst and Catalytic Hydrogen Storage in N-Methylindole. In this example, Ru5K4 refers to 5% by mass of Ru and 4% by mass of K)

[0039] The preparation process of Ru5K4 / γ-Al2O3 is the same as that of Example 1, except that the amount of KCl is changed to 382 mg. The continuous hydrogen storage process of Ru5K4 / γ-Al2O3 catalyst in a fixed bed reactor is the same as that of Example 1. The hydrogen storage density of the catalyst can be found in Figure 2 .

[0040] Example 3 (Preparation of Ru5K6 / γ-Al2O3 Catalyst and Catalytic N-Methylindole Hydrogen Storage. In this example, Ru5K6 refers to 5% by mass of Ru and 6% by mass of K)

[0041] The preparation process of Ru5K6 / γ-Al2O3 is the same as that of Example 1, except that the amount of KCl is changed to 573 mg. The continuous hydrogen storage process of Ru5K6 / γ-Al2O3 catalyst in a fixed bed reactor is the same as that of Example 1. The hydrogen storage density of the catalyst can be found in Figure 2 .

[0042] Comparative Example 1 (Preparation of Ru5 / γ-Al2O3 Catalyst and Catalytic N-Methylindole Hydrogen Storage, in this comparative example, Ru5 refers to 5% by mass of Ru)

[0043] Preparation of catalyst precursor: Dissolve 530 mg of RuCl3 in 5 mL of deionized water and ultrasonicate for 10 min to form a uniform RuCl3 solution. Use a dropper to slowly add the RuCl3 solution drop by drop into γ-Al2O3. After the addition is complete, seal it with plastic wrap, place it in a cool and dry place for 12 hours, move it to a 60°C oven and slowly dry it for 12 hours. After drying, move it into a tubular furnace and calcine it at 450°C for 4 hours under a nitrogen atmosphere to obtain a catalyst precursor.

[0044] Preparation of Ru5 / γ-Al2O3 catalyst: Move 5 g of the above catalyst precursor into a tubular furnace, introduce 5% hydrogen and argon gas at a flow rate of 100 mL / min, and heat the temperature to 450°C at a rate of 5°C / min, and maintain at 450°C for 4 hours to complete the reduction of the catalyst precursor and obtain Ru5 / γ-Al2O3 catalyst.

[0045] Ru5 / γ-Al2O3 catalyst continuously stores hydrogen in a fixed bed reactor. 2g of the catalyst was loaded into the constant temperature zone of the fixed bed reaction tube. Before the reaction started, nitrogen was replaced for 3 minutes. After nitrogen replacement, 1MPa pressure hydrogen was replaced for 3 minutes. After hydrogen replacement, the hydrogen pressure was increased to 5MPa. After the pressure increase, the preheater and reaction column temperature were set to 130°C. After the temperature stabilized, N-methylindole was pumped into the reactor at a flow rate of 0.1mL / min, and the hydrogen flow rate was 90mL / min. After the reaction system stabilized, the liquid product was taken every 1h for quantitative analysis using a gas chromatograph. For the hydrogen storage density of the catalyst, please refer to Figure 2 .

[0046] Comparative Example 2: (Preparation of Ru5 / ZSM-5 catalyst and catalytic N-methylindole hydrogen storage. In this comparative example, Ru5 refers to 5% by mass of Ru)

[0047] The preparation process of Ru5 / ZSM-5 catalyst is the same as that of Comparative Example 1. The continuous hydrogen storage process of Ru5 / ZSM-5 in a fixed bed reactor is the same as that of Example 1. The hydrogen storage density of the catalyst is shown in FIG. Figure 2 .

[0048] It should be noted that the carrier ZSM-5 is a specific molecular sieve material, which belongs to the zeolite family and is a zeolite molecular sieve containing organic amine cations.

[0049] Comparative Example 3 (Preparation of Ru5 / TS-1 Catalyst and Catalytic Hydrogen Storage in N-Methylindole, in this comparative example, Ru5 refers to 5% by mass of Ru)

[0050] The preparation process of Ru5 / TS-1 is the same as that of Comparative Example 1. The continuous hydrogen storage process of Ru5 / TS-1 in a fixed bed reactor is the same as that of Example 1. The hydrogen storage density of the catalyst is shown in Figure 2 .

[0051] It should be noted that the carrier TS-1 (Titanium Silicalite-1) is a special zeolite catalyst, which is a titanium-containing molecular sieve and belongs to the MFI (Materials Research Society Fibonacci Intermediates) structure type.

[0052] Based on the above examples and comparative examples, the following conclusions can be drawn by analyzing the results:

[0053] 1. Compared with ZSM-5 and TS-1, the catalytic performance of Ru5 / γ-Al2O3 catalyst prepared with γ-Al2O3 as carrier is significantly improved. The hydrogen storage density of Ru5 / γ-Al2O3 for N-methylindole continuous hydrogenation in the first 7 hours is above 5.7wt%, and the decreasing trend of hydrogen storage density is slower than that of catalysts Ru5 / ZSM-5 and Ru5 / TS-1.

[0054] 2. The comparison results of Example 1, Example 2, Example 3 and Comparative Example 1 show that the addition of the co-active component K can significantly improve the life of the catalyst. Among them, the hydrogen storage density of Example 2 is above 5.0wt% for 31h, which is greater than 16h of Comparative Example 1.

[0055] 3. Comparison between Example 1, Example 2 and Example 3 shows that the amount of potassium added also affects the life of the catalyst. In Example 2, the amount of potassium added is 4wt%, which is significantly longer than the life of the catalyst with 2wt% potassium added (Example 1) and 6wt% potassium added.

[0056] That is to say, through the above technical scheme, first, the catalyst prepared by the method for preparing the catalyst of the present invention has a longer catalytic life. Specifically, the addition of the co-active component of the present invention can significantly improve the catalytic life of the catalyst, which is conducive to the longer storage of hydrogen of N-heterocyclic aromatic hydrocarbons in a continuous flow fixed bed reactor. In this way, it is also possible to effectively delay the time for the catalyst to undergo structural changes or the loss of active ingredients, which is conducive to ensuring the catalytic performance of the catalyst for a relatively longer period of time, thereby effectively improving the catalytic efficiency.

[0057] Second, the co-active component of the present invention is a cheap alkali metal component, which can significantly increase the catalytic life of the catalyst while also helping to improve production efficiency and reduce manufacturing costs, thereby making hydrogen storage more economically beneficial.

[0058] Third, the addition of potassium as an active ingredient can significantly increase the life of the catalyst. It should be noted that after adding 4wt% of potassium, the life of the catalyst can be extended from 16h to 31h compared to the catalyst without potassium (at the same time, the hydrogen storage density is ensured to be greater than or equal to 5.0wt%).

[0059] like Figure 1 As shown, a method for preparing a catalyst of the present invention may include the following steps:

[0060] Step S1: crushing 2mm-4mm γ-Al2O3 into 20-40 mesh;

[0061] Step S2: Mix the crushed γ-Al2O3 material obtained in step S1 with the precursor solution of the auxiliary active component, and perform impregnation, drying and calcination in sequence to obtain a catalyst precursor I; wherein the auxiliary active component is one or more of potassium, sodium and magnesium.

[0062] Step S3: Mixing catalyst precursor I with an active component precursor solution, and sequentially performing impregnation, drying and calcination to obtain catalyst precursor II; wherein the active component is one or more of ruthenium, nickel, rhodium and palladium.

[0063] Step S4: subjecting the catalyst precursor II to programmed temperature reduction in an argon-hydrogen atmosphere to obtain a catalyst.

[0064] Thus, through the above technical solution, first, γ-Al2O3 of 2mm-4mm can be selected as raw material, which is not only easier to purchase but also cheaper. γ-Al2O3 particles of this size are larger, which can be convenient for batch processing, and the energy consumption in the crushing process is relatively low. At the same time, crushing from larger particles can more effectively control the particle size distribution of the final product. Larger particles are easier to reach the required particle size range during the crushing process, reducing the need for ultrafine grinding.

[0065] Second, the γ-Al2O3 is crushed into 20-40 meshes, so that the crushed γ-Al2O3 can provide a moderate specific surface area, which can ensure sufficient active sites and maintain good mass transfer performance. This balance helps to improve the activity and selectivity of the catalyst. At the same time, when the prepared catalyst is used in a fixed bed reactor, the 20-40 mesh particles can provide a moderate pressure drop, which is neither too high to increase energy consumption nor too low to cause fluid short circuit. In addition, particles in this particle size range are easy to handle and load, and are also easy to remove or replace from the reactor when necessary.

[0066] In addition, it is understandable that in another embodiment, commercial γ-Al2O3 with a mesh size of 20-40 can be directly selected to omit the crushing step and improve the catalyst preparation efficiency.

[0067] According to the second aspect of the present invention, a catalyst is also provided, which is prepared by the preparation method as described in any technical solution in the first aspect of the present invention; and / or the components of the catalyst include an active component, a co-active component and a carrier, wherein the co-active component is one or more of potassium, sodium, and magnesium, and the content of the co-active component can be 1wt%-10wt%, the active component is one or more of ruthenium, nickel, rhodium, and palladium, and the content of the active component can be 1wt%-5wt%, and the carrier is γ-Al2O3.

[0068] According to a third aspect of the present invention, there is also provided an application of the catalyst described in any one of the technical solutions in the second aspect of the present invention for hydrogen storage in a fixed bed reactor;

[0069] The specific steps may include: loading the catalyst into a fixed bed reactor, the H2 pressure is between 0.1MPa-7MPa, preferably 4MPa-6MPa, the H2 flow rate is between 1mL / min-90mL / min, preferably 70mL / min-90mL / min, the N-heterocyclic aromatic hydrocarbon flow rate is between 0.01mL / min-3mL / min, and the reaction temperature is between 90℃-150℃, preferably 90℃-130℃.

[0070] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for preparing a catalyst, characterized in that: The steps include: Step S1: crushing γ-Al2O3; Step S2: mixing the crushed γ-Al2O3 material obtained in step S1 with the precursor solution of the auxiliary active component, and sequentially performing impregnation, drying and calcination to obtain a catalyst precursor I; Step S3: mixing the catalyst precursor I with the active component precursor solution, and sequentially performing impregnation, drying and calcination to obtain the catalyst precursor II; Step S4: subjecting the catalyst precursor II to programmed temperature reduction in an argon-hydrogen atmosphere to obtain a catalyst.

2. The method for preparing a catalyst according to claim 1, characterized in that: In the step S1, the particle size of γ-Al2O3 is 2 mm-4 mm.

3. The method for preparing the catalyst according to claim 1, characterized in that: In the step S1, γ-Al2O3 is crushed into 20-40 meshes.

4. The method for preparing the catalyst according to claim 1, characterized in that: The co-active component is one or more of potassium, sodium and magnesium.

5. The method for preparing the catalyst according to claim 1, characterized in that: The active component is one or more of ruthenium, nickel, rhodium and palladium.

6. A catalyst, characterized in that The catalyst is prepared by the preparation method described in any one of claims 1 to 5; and / or the components of the catalyst include an active component, a co-active component and a carrier, wherein the co-active component is one or more of potassium, sodium, and magnesium, the active component is one or more of ruthenium, nickel, rhodium, and palladium, and the carrier is γ-Al2O3.

7. The catalyst according to claim 6, characterized in that The content of the active component is 1wt%-5wt%.

8. The catalyst according to claim 6, characterized in that The content of the co-active component is 1wt%-10wt%.

9. Use of the catalyst according to any one of claims 6 to 8 for hydrogen storage in a fixed bed reactor.

10. Use of the catalyst according to claim 9 for hydrogen storage in a fixed bed reactor, characterized in that: include: The catalyst is loaded into a fixed bed reactor, the H2 pressure is between 0.1MPa-7MPa, the H2 flow rate is between 1mL / min-90mL / min, the N-heterocyclic aromatic hydrocarbon flow rate is between 0.01mL / min-3mL / min, and the reaction temperature is between 90℃-150℃.

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