A porous aluminum support catalyst and a method for preparing the same
By preparing porous aluminum-supported catalysts, forming pores through acid etching and introducing ruthenium active components, the problem of sintering of ruthenium-based catalysts at high temperatures was solved, achieving high efficiency and long lifespan of the catalysts.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA PETROLEUM & CHEMICAL CORP
- Filing Date
- 2024-12-19
- Publication Date
- 2026-06-23
AI Technical Summary
Ruthenium-based catalysts are prone to sintering at high temperatures, which shortens their catalyst life and limits their effectiveness in industrial applications.
A porous aluminum-supported catalyst is used. A uniformly distributed aluminum support is formed through co-precipitation, pores are formed by acid etching, and ruthenium active components are introduced. Finally, the catalyst is calcined to form a porous structure. An auxiliary agent is used as a synergistic active site to avoid sintering of the ruthenium active components.
It improves the activity and lifespan of the catalyst, and extends the service life of the catalyst.
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Abstract
Description
Technical Field
[0001] This invention relates to a porous aluminum-supported catalyst and its preparation method, belonging to the field of catalyst preparation technology. Background Technology
[0002] Ruthenium-based catalysts have a wide range of applications, playing a significant role in reactions such as ammonia decomposition for hydrogen production, methanol synthesis, and syngas-to-natural gas production. However, ruthenium, as the active component, is prone to thermal sintering, which affects catalyst lifespan and severely restricts its further industrial application.
[0003] To avoid the sintering of the ruthenium active component, there are two approaches: one is to confine the active component using a porous support; the other is to introduce additives to regulate the electronic structure of the active component and space it apart, thereby preventing the active component from thermally sintering.
[0004] Based on these two approaches, this invention provides a porous aluminum-supported catalyst and its preparation method. The catalyst utilizes aluminum nitrate and an additive to co-precipitate under the action of a dispersant to form a uniformly distributed aluminum support. Subsequently, the metal in the pores of the aluminum support is dissolved by acid etching to form pores. The additive in the aluminum support structure is retained as a synergistic active site. Then, ruthenium active components are introduced by impregnation. Finally, the catalyst is obtained after calcination. Summary of the Invention
[0005] The purpose of this invention is to provide a porous aluminum-supported catalyst and its preparation method.
[0006] The main technical solution of this invention is a porous aluminum-supported catalyst, characterized in that the catalyst uses porous aluminum as a support, ruthenium as the active component, and the molar ratio of ruthenium to aluminum is 1:10-1:100; the catalyst has the following structural features: (1) Bulk density 0.78~0.83 g / mL; (2) Pore volume 0.36~0.41 cc / g, mesoporous ratio of 10~30 nm >55%; (3) The ruthenium crystal size is 3.8~4.3 nm.
[0007] This invention also provides a method for preparing a porous aluminum-supported catalyst, characterized in that aluminum nitrate and an additive are co-precipitated under the action of a dispersant to form a uniformly distributed aluminum support, and then the metal in the pores of the aluminum support is dissolved by acid etching to form pores. The additive in the aluminum support structure is retained as a synergistic active site, and then ruthenium active components are introduced by impregnation. Finally, the catalyst is obtained after calcination.
[0008] The method for preparing the catalyst provided by the present invention specifically includes the following steps: 1. Aluminum nitrate and additives are co-precipitated with a dispersant to form a uniformly distributed aluminum carrier.
[0009] Preferably, the additive is one of copper salt, zinc salt, nickel salt, chromium salt, manganese salt, and magnesium salt.
[0010] Preferably, the molar ratio of the added additive to aluminum is 1:1 to 1:10.
[0011] Preferably, the aluminum carrier precipitation temperature is 25-80 ℃, and the final pH is 7-10.
[0012] Preferably, the dispersant is one of polyvinyl alcohol, polyacrylate, triethylhexyl phosphate, and sodium dodecyl sulfate.
[0013] 2. Acid etching is used to dissolve the metal inside the aluminum carrier channels to form pores.
[0014] Preferably, the etching acid is one of sulfuric acid, hydrochloric acid, and nitric acid.
[0015] Preferably, the etching time is 10-60 min and the etching temperature is 25-80 ℃. 3. Introduce ruthenium active components through impregnation.
[0016] Preferably, the immersion temperature is 25-80 ℃ and the immersion time is 1-12 h.
[0017] 4. The corresponding catalyst is obtained after calcination.
[0018] Preferably, the calcination temperature is 400-500 ℃ and the calcination time is 3-5 h.
[0019] The porous aluminum-supported catalyst provided by this invention increases the dispersion of the aluminum support by using a dispersant during the preparation process, and uses some of the auxiliary agents in situ as sacrificial templates to obtain an aluminum support with a porous structure. Through the confinement of the porous aluminum support and the synergistic effect of the auxiliary agents retained in the porous aluminum support, the sintering of the ruthenium active component is avoided. Detailed Implementation
[0020] The following specific examples are only used to further illustrate the technical solution of the present invention, and the effects of the method of the present invention are not limited thereto. Example 1
[0021] (1) Prepare 1 L of a mixed aqueous solution of 1 mol / L aluminum nitrate, 1 mol / L copper nitrate and 0.1 mol / L polyvinyl alcohol, and neutralize it with NaOH at 80 °C until the final pH is 10. After filtration and washing, the resulting solid is dried in an oven at 110 °C for later use.
[0022] (2) Soak 50 g of aluminum carrier in 50 mL of 0.1 mol / L hydrochloric acid aqueous solution at 25 °C for 10 minutes. Then filter and wash the aluminum carrier and dry it in an oven at 110 °C for later use.
[0023] (3) Impregnate an equal volume of ruthenium trichloride aqueous solution in 50 g aluminum carrier to make the ruthenium-aluminum molar ratio 1:10. Impregnate at 25 °C for 1 h, dry directly in an oven at 110 °C, and then calcine in a muffle furnace at 400 °C for 3 h. Example 2
[0024] (1) Prepare 1 L of a mixed aqueous solution of 1 mol / L aluminum nitrate, 1 mol / L zinc nitrate and 0.1 mol / L polyvinyl alcohol, and neutralize it with NaOH at 80 °C until the final pH is 10. After filtration and washing, the resulting solid is dried in an oven at 110 °C for later use.
[0025] (2) Soak 50 g of aluminum carrier in 50 mL of 0.1 mol / L hydrochloric acid aqueous solution at 25 °C for 10 minutes. Then filter and wash the aluminum carrier and dry it in an oven at 110 °C for later use.
[0026] (3) Impregnate an equal volume of ruthenium trichloride aqueous solution in 50 g aluminum carrier to make the ruthenium-aluminum molar ratio 1:10. Impregnate at 25 °C for 1 h, dry directly in an oven at 110 °C, and then calcine in a muffle furnace at 400 °C for 3 h. Example 3
[0027] (1) Prepare 1 L of a mixed aqueous solution of 1 mol / L aluminum nitrate, 1 mol / L copper nitrate and 1 mol / L polyvinyl alcohol, and neutralize it with NaOH at 80 °C until the final pH is 10. After filtration and washing, the resulting solid is dried in an oven at 110 °C for later use.
[0028] (2) Soak 50 g of aluminum carrier in 50 mL of 0.1 mol / L hydrochloric acid aqueous solution at 25 °C for 10 minutes. Then filter and wash the aluminum carrier and dry it in an oven at 110 °C for later use.
[0029] (3) Impregnate an equal volume of ruthenium trichloride aqueous solution in 50 g aluminum carrier to make the ruthenium-aluminum molar ratio 1:10. Impregnate at 25 °C for 1 h, dry directly in an oven at 110 °C, and then calcine in a muffle furnace at 400 °C for 3 h. Example 4
[0030] (1) Prepare 1 L of a mixed aqueous solution of 1 mol / L aluminum nitrate, 1 mol / L copper nitrate and 0.1 mol / L polyvinyl alcohol, and neutralize it with NaOH at 25 °C until the final pH is 7. After filtration and washing, the resulting solid is dried in an oven at 110 °C for later use.
[0031] (2) Soak 50 g of aluminum carrier in 50 mL of 0.1 mol / L hydrochloric acid aqueous solution at 25 °C for 10 minutes. Then filter and wash the aluminum carrier and dry it in an oven at 110 °C for later use.
[0032] (3) Impregnate an equal volume of ruthenium trichloride aqueous solution in 50 g aluminum carrier to make the ruthenium-aluminum molar ratio 1:10. Impregnate at 25 °C for 1 h, dry directly in an oven at 110 °C, and then calcine in a muffle furnace at 400 °C for 3 h. Example 5
[0033] (1) Prepare 1 L of a mixed aqueous solution of 1 mol / L aluminum nitrate, 1 mol / L copper nitrate and 0.1 mol / L polyacrylate, and neutralize it with NaOH at 80 °C until the final pH is 10. After filtration and washing, the resulting solid is dried in an oven at 110 °C for later use.
[0034] (2) Soak 50 g of aluminum carrier in 50 mL of 0.1 mol / L hydrochloric acid aqueous solution at 25 °C for 10 minutes. Then filter and wash the aluminum carrier and dry it in an oven at 110 °C for later use.
[0035] (3) Impregnate an equal volume of ruthenium trichloride aqueous solution in 50 g aluminum carrier to make the ruthenium-aluminum molar ratio 1:10. Impregnate at 25 °C for 1 h, dry directly in an oven at 110 °C, and then calcine in a muffle furnace at 400 °C for 3 h. Example 6
[0036] (1) Prepare 1 L of a mixed aqueous solution of 1 mol / L aluminum nitrate, 1 mol / L copper nitrate and 0.1 mol / L triethylhexyl phosphoric acid, and neutralize it with NaOH at 80 °C until the final pH is 10. After filtration and washing, the resulting solid is dried in an oven at 110 °C for later use.
[0037] (2) Soak 50 g of aluminum carrier in 50 mL of 0.1 mol / L sulfuric acid aqueous solution at 25 °C for 10 minutes. Then filter and wash the aluminum carrier and dry it in an oven at 110 °C for later use.
[0038] (3) Impregnate an equal volume of ruthenium trichloride aqueous solution in 50 g aluminum carrier to make the ruthenium-aluminum molar ratio 1:10. Impregnate at 25 °C for 1 h, dry directly in an oven at 110 °C, and then calcine in a muffle furnace at 400 °C for 3 h. Example 7
[0039] (1) Prepare 1 L of a mixed aqueous solution of 1 mol / L aluminum nitrate, 1 mol / L copper nitrate and 0.1 mol / L sodium dodecyl sulfate, and neutralize it with NaOH at 80 °C until the final pH is 10. After filtration and washing, the resulting solid is dried in an oven at 110 °C for later use.
[0040] (2) Soak 50 g of aluminum carrier in 50 mL of 0.1 mol / L hydrochloric acid aqueous solution at 80 ℃ for 60 minutes. Then filter and wash the aluminum carrier and dry it in an oven at 110 ℃ for later use.
[0041] (3) Impregnate an equal volume of ruthenium trichloride aqueous solution in 50 g aluminum carrier to make the ruthenium-aluminum molar ratio 1:10. Impregnate at 25 °C for 1 h, dry directly in an oven at 110 °C, and then calcine in a muffle furnace at 400 °C for 3 h. Example 8
[0042] (1) Prepare 1 L of a mixed aqueous solution of 1 mol / L aluminum nitrate, 1 mol / L copper nitrate and 0.1 mol / L polyvinyl alcohol, and neutralize it with NaOH at 80 °C until the final pH is 10. After filtration and washing, the resulting solid is dried in an oven at 110 °C for later use.
[0043] (2) Soak 50 g of aluminum carrier in 50 mL of 0.1 mol / L hydrochloric acid aqueous solution at 25 °C for 10 minutes. Then filter and wash the aluminum carrier and dry it in an oven at 110 °C for later use.
[0044] (3) Impregnate an equal volume of ruthenium trichloride aqueous solution into a 50 g aluminum carrier, so that the molar ratio of ruthenium to aluminum is 1:10. Impregnate at 80 °C for 12 h, dry directly in an oven at 110 °C, and then calcine in a muffle furnace at 400 °C for 3 h. Example 9
[0045] (1) Prepare 1 L of a mixed aqueous solution of 1 mol / L aluminum nitrate, 1 mol / L copper nitrate and 0.1 mol / L polyvinyl alcohol, and neutralize it with NaOH at 80 °C until the final pH is 10. After filtration and washing, the resulting solid is dried in an oven at 110 °C for later use.
[0046] (2) Soak 50 g of aluminum carrier in 50 mL of 0.1 mol / L hydrochloric acid aqueous solution at 25 °C for 10 minutes. Then filter and wash the aluminum carrier and dry it in an oven at 110 °C for later use.
[0047] (3) Impregnate an equal volume of ruthenium trichloride aqueous solution into a 50 g aluminum carrier to achieve a ruthenium-aluminum molar ratio of 1:100. Impregnate at 25 °C for 1 h, dry directly in an oven at 110 °C, and then calcine in a muffle furnace at 400 °C for 3 h. Example 10
[0048] (1) Prepare 1 L of a mixed aqueous solution of 1 mol / L aluminum nitrate, 1 mol / L copper nitrate and 0.1 mol / L polyvinyl alcohol, and neutralize it with NaOH at 80 °C until the final pH is 10. After filtration and washing, the resulting solid is dried in an oven at 110 °C for later use.
[0049] (2) Soak 50 g of aluminum carrier in 50 mL of 0.1 mol / L hydrochloric acid aqueous solution at 25 °C for 10 minutes. Then filter and wash the aluminum carrier and dry it in an oven at 110 °C for later use.
[0050] (3) Impregnate an equal volume of ruthenium trichloride aqueous solution into a 50 g aluminum carrier, so that the molar ratio of ruthenium to aluminum is 1:10. Impregnate at 25 °C for 1 h, dry directly in an oven at 110 °C, and then calcine in a muffle furnace at 500 °C for 5 h.
[0051] Comparative Example (1) Prepare 1 L of a mixed aqueous solution of 1 mol / L aluminum nitrate and 1 mol / L copper nitrate, and neutralize it with NaOH at 80 °C until the final pH is 10. After filtration and washing, the resulting solid is dried in an oven at 110 °C for later use.
[0052] (2) Impregnate an equal volume of ruthenium trichloride aqueous solution into a 50 g aluminum carrier, so that the molar ratio of ruthenium to aluminum is 1:10. Impregnate at 25 °C for 1 h, dry directly in an oven at 110 °C, and then calcine in a muffle furnace at 400 °C for 3 h.
[0053] Activity testing conditions: Taking ammonia decomposition for hydrogen production as an example, the changes in catalyst activity were investigated. The catalyst loading was 2 mL, and the test was conducted under pure ammonia gas and a space velocity of 10000 h⁻¹. -1 The ammonia decomposition activity of the catalyst under different temperatures was investigated under atmospheric pressure. The physicochemical characterization results, activity evaluation results, and catalyst lifetime results of the examples and comparative examples are shown in Tables 1-3.
[0054] Table 1: Physical and chemical characterization results
[0055] Table 2: Activity Evaluation Results
[0056] Table 3: Catalyst lifetime results
[0057] As can be seen from the physicochemical characterization of the above embodiments and comparative examples, the catalyst prepared by this invention exhibits a significantly increased proportion of pore sizes in the 10-30 nm range, demonstrating the formation of a rich pore structure. The activity and lifetime evaluation results show that the catalyst prepared by this invention exhibits increased activity and a significantly prolonged lifetime, proving the effectiveness of this invention.
[0058] As is known from common technical knowledge, this invention can be implemented through other embodiments that do not depart from its spirit or essential characteristics. Therefore, the disclosed embodiments described above are merely illustrative in all respects and are not the only ones. All modifications within the scope of this invention or equivalent to the scope of this invention are included in this invention.
Claims
1. A porous aluminum-supported catalyst, characterized in that... The catalyst uses porous aluminum as a support and ruthenium as the active component, with a ruthenium to aluminum molar ratio of 1:10 to 1:100; the catalyst has the following structural characteristics: (1) Bulk density 0.78~0.83 g / mL; (2) Pore volume 0.36~0.41 cc / g, mesoporous ratio of 10~30 nm >55%; (3) The ruthenium crystal size is 3.8~4.3 nm.
2. The method for preparing the catalyst as described in claim 1, characterized in that: A uniformly distributed aluminum support is formed by co-precipitation of aluminum nitrate and additives under the action of a dispersant. Then, the metal in the pores of the aluminum support is dissolved by acid etching to form pores. The additives in the aluminum support structure are retained as synergistic active sites. Ruthenium active components are then introduced by impregnation. Finally, the catalyst is obtained by calcination.
3. The preparation method according to claim 2, characterized in that... The additives are selected from one of the following: copper salt, zinc salt, nickel salt, chromium salt, manganese salt, and magnesium salt.
4. The preparation method according to claim 2, characterized in that... The molar ratio of the additive to aluminum is 1:1 to 1:
10.
5. The preparation method according to claim 2, characterized in that... The precipitation temperature of aluminum carrier is 25-80 ℃, and the final pH is 7-10.
6. The preparation method according to claim 2, characterized in that... The dispersant is selected from one of polyvinyl alcohol, polyacrylate, triethylhexyl phosphate, and sodium dodecyl sulfate.
7. The preparation method according to claim 2, characterized in that... The etching acid is selected from sulfuric acid, hydrochloric acid, and nitric acid.
8. The preparation method according to claim 2, characterized in that... The etching time is 10-60 min, and the etching temperature is 25-80℃.
9. The preparation method according to claim 2, characterized in that... The immersion temperature is 25-80 ℃, and the immersion time is 1-12 h.
10. The preparation method according to claim 2, characterized in that... The roasting temperature is 400-500 ℃ and the roasting time is 3-5 hours.