A noble metal catalyst, a method for preparing the same, and an application thereof
Ruthenium was supported on a composite support of foamed silicon carbide, carbon nanotubes and molecular sieves to prepare a noble metal catalyst, which solved the problem of insufficient activity of existing catalysts and achieved efficient conversion of butene to butadiene, exhibiting excellent catalytic activity and stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NEI MONGOL SHENGLONG DADI TECH CO LTD
- Filing Date
- 2026-04-16
- Publication Date
- 2026-07-10
AI Technical Summary
Existing catalysts have insufficient catalytic activity in the oxidative dehydrogenation of butene to 1,3-butadiene, making it difficult to meet the growing downstream demand.
Ruthenium precursors were supported on a composite support of foamed silicon carbide, carbon nanotubes and molecular sieves, and noble metal catalysts were prepared by calcination. The support composition and loading conditions were optimized to improve catalytic activity.
It significantly improved butene conversion and butadiene selectivity, and achieved a stable operating time of 2100~2300 hours, demonstrating excellent catalytic activity and stability.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of catalytic dehydrogenation technology, specifically relating to a noble metal catalyst, its preparation method, and its application. Background Technology
[0002] 1,3-Butadiene, with its unique conjugated double bond structure, is widely used in the industrial synthesis of chemical products such as styrene-butadiene rubber, nitrile rubber, butadiene rubber, acrylonitrile-butadiene-styrene resin, and nylon-66, playing a crucial role in petrochemical production. Driven by the robust demand in the synthetic rubber industry, downstream demand for 1,3-butadiene is increasing daily. However, the traditional method of extracting 1,3-butadiene from C4 byproducts of ethylene cracking has been significantly impacted by the trend towards lighter feedstocks in ethylene cracking, leading to a tighter supply of 1,3-butadiene. Therefore, the route of producing 1,3-butadiene via butene oxidative dehydrogenation has attracted widespread attention. Currently, Fe2O3 / Al2O3 and Pt / Al2O3 catalysts are used. Although these catalysts have improved conversion rates to some extent, designing and synthesizing highly active catalysts remains one of the major challenges in this field. Summary of the Invention
[0003] The purpose of this invention is to provide a noble metal catalyst, its preparation method, and its application. The noble metal catalyst prepared by the method provided by this invention exhibits excellent catalytic activity and can significantly improve the conversion rate of butene and the selectivity of butadiene.
[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a method for preparing a noble metal catalyst, comprising the following steps: (1) A composite carrier is obtained by mixing foamed silicon carbide, carbon nanotubes and molecular sieves; (2) The composite carrier obtained in step (1) is mixed with a ruthenium precursor solution and loaded to obtain a carrier loaded with the precursor; (3) The carrier loaded with precursor obtained in step (2) is calcined to obtain a noble metal catalyst.
[0005] Preferably, the molecular sieve in step (1) includes ZSM-5 type molecular sieve and / or Silicalite-1 molecular sieve.
[0006] Preferably, in step (1), the mass ratio of foamed silicon carbide, carbon nanotubes and molecular sieve is (1~5):(1~2);(0.5~3).
[0007] Preferably, the concentration of the ruthenium precursor solution in step (2) is 5~10 mg / mL.
[0008] Preferably, in step (2), the mass ratio of the composite carrier to the volume ratio of the ruthenium precursor solution is (150~200) mg: (1~2) mL.
[0009] Preferably, the temperature of the load in step (2) is 50~60℃ and the loading time is 2~3h.
[0010] Preferably, the calcination in step (3) is carried out in a hydrogen atmosphere.
[0011] Preferably, the roasting temperature in step (3) is 100~600℃ and the roasting time is 1~5h.
[0012] The present invention also provides a noble metal catalyst prepared by the preparation method described in the above technical solution.
[0013] The present invention also provides the application of the noble metal catalyst described in the above technical solution in catalytic dehydrogenation.
[0014] This invention provides a method for preparing a noble metal catalyst, comprising the following steps: mixing foamed silicon carbide, carbon nanotubes, and molecular sieves to obtain a composite support; mixing the composite support with a ruthenium-containing precursor solution for loading to obtain a precursor-loaded support; and calcining the precursor-loaded support to obtain the noble metal catalyst. This invention, by combining multiple supports, can synergistically improve the catalytic activity of the noble metal catalyst; further enhancing the catalytic activity by loading noble metals onto the composite support. Experimental results show that when the noble metal catalyst prepared by this invention is applied to the catalytic conversion of butene to butadiene, the butene conversion rate is 84.1–89.3%, the butadiene selectivity is 96.5–98.9%, and the stable operating time is 2100–2300 h. Detailed Implementation
[0015] This invention provides a method for preparing a noble metal catalyst, comprising the following steps: (1) A composite carrier is obtained by mixing foamed silicon carbide, carbon nanotubes and molecular sieves; (2) The composite carrier obtained in step (1) is mixed with a ruthenium precursor solution and loaded to obtain a carrier loaded with the precursor; (3) The carrier loaded with precursor obtained in step (2) is calcined to obtain a noble metal catalyst.
[0016] This invention does not impose any special restrictions on the source of the raw materials; commercially available products familiar to those skilled in the art can be used.
[0017] This invention mixes foamed silicon carbide, carbon nanotubes and molecular sieves to obtain a composite carrier.
[0018] In this invention, the pore size of the foamed silicon carbide is preferably 0.5~3 mm, more preferably 0.5~1.5 mm; the specific surface area of the foamed silicon carbide is preferably 5~200 m². 2 / g, more preferably 50~150m 2 / g.
[0019] In this invention, the foamed silicon carbide is preferably in the shape of granules or cylinders; the diameter of the granules is preferably 2-50 mm; the diameter of the cylinders is preferably 2-100 mm; and the height of the cylinders is preferably 3-200 mm. In this invention, the foamed silicon carbide serves as the main carrier for loading the active components.
[0020] In this invention, the outer diameter of the carbon nanotubes is preferably 4-6 mm; the length of the carbon nanotubes is preferably 0.5-2 µm. In this invention, the carbon nanotubes are used in combination with foamed silicon carbide to improve the activity of the catalyst.
[0021] In this invention, the molecular sieve preferably includes ZSM-5 type molecular sieve and / or Silicalite-1 molecular sieve, more preferably ZSM-5 type molecular sieve and Silicalite-1 molecular sieve. In this invention, the molecular sieve is used to compound with foamed silicon carbide, thereby improving the activity of the catalyst.
[0022] In this invention, the specific surface area of the Silicalite-1 molecular sieve is preferably 380~420 m². 2 / g; the total pore volume of the Silicalite-1 molecular sieve is preferably 0.49~0.55cm³. 3 / g.
[0023] In this invention, when the molecular sieve is a ZSM-5 molecular sieve and a Silicalite-1 molecular sieve, the preferred mass ratio of the ZSM-5 molecular sieve to the Silicalite-1 molecular sieve is 1:3. This invention can further improve the activity of the catalyst by controlling the mass ratio of the two molecular sieves.
[0024] In this invention, the preferred mass ratio of the foamed silicon carbide, carbon nanotubes, and molecular sieve is (1~5):(1~2):(0.5~3), more preferably (2~4):(1~1.5):(1~2), and even more preferably 3:1:1. By limiting the mass ratio of the foamed silicon carbide, carbon nanotubes, and molecular sieve within the above range, this invention achieves a synergistic effect, thereby further improving the activity of the catalyst.
[0025] The present invention does not have any special limitations on the operation of mixing the foamed silicon carbide, carbon nanotubes and molecular sieves, and any technical solution for preparing the mixture well known to those skilled in the art can be used.
[0026] After obtaining the composite carrier, the present invention mixes the composite carrier with a ruthenium-containing precursor solution and loads it to obtain a carrier loaded with the precursor.
[0027] In this invention, the ruthenium-containing precursor preferably includes one of ruthenium powder, ruthenium trichloride hydrate, ruthenium iodide, ruthenium acetate, ruthenium oxide, carbonyl ruthenium chloride, ruthenium trichloride, and triphenylphosphine ruthenium chloride, more preferably one of ruthenium trichloride hydrate, ruthenium oxide, and ruthenium trichloride.
[0028] In this invention, the concentration of the ruthenium-containing precursor solution is preferably 5-10 mg / mL, more preferably 6-8 mg / mL. This invention does not impose any particular limitation on the preparation method of the ruthenium-containing precursor solution; any method well-known to those skilled in the art can be used.
[0029] In this invention, the solvent for the ruthenium-containing precursor solution is preferably deionized water.
[0030] In this invention, the preferred mass ratio of the composite carrier to the volume ratio of the ruthenium precursor solution is (150~200) mg: (1~2) mL, and more preferably (160~180) mg: 1 mL.
[0031] The present invention does not have any special limitations on the operation of mixing the composite carrier with the ruthenium-containing precursor solution, and any technical solution for preparing the mixture well known to those skilled in the art can be used.
[0032] In this invention, the temperature of the loading is preferably 50-60°C, more preferably 52-58°C; the loading time is preferably 2-3 hours. By limiting the loading temperature and time within the above ranges, this invention can increase the loading of noble metals, thereby improving the catalytic activity of the catalyst.
[0033] After loading is completed, the present invention preferably filters and dries the product obtained by loading in sequence to obtain a carrier loaded with the precursor.
[0034] The present invention does not impose any special limitations on the filtering operation; any operation known to those skilled in the art can be used.
[0035] The present invention does not impose any special limitations on the drying operation; drying to a constant weight is sufficient.
[0036] After obtaining the support loaded with the precursor, the present invention calcines the support loaded with the precursor to obtain a noble metal catalyst.
[0037] In this invention, the calcination temperature is preferably 100~600℃, more preferably 200~300℃; the calcination time is preferably 1~5h, more preferably 2~4h; and the calcination is preferably carried out in a hydrogen atmosphere.
[0038] This invention utilizes a combination of supports to synergistically enhance the catalytic activity of noble metal catalysts; further enhancing the catalytic activity of catalysts by loading noble metals onto composite supports.
[0039] The present invention also provides a noble metal catalyst prepared by the preparation method described in the above technical solution.
[0040] The noble metal catalyst provided by this invention possesses excellent catalytic activity and stability.
[0041] The present invention also provides the application of the noble metal catalyst described in the above technical solution in catalytic dehydrogenation.
[0042] The present invention does not impose any special limitations on the operation of the noble metal catalyst in catalytic dehydrogenation; any operation known to those skilled in the art can be used.
[0043] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.
[0044] Example 1 The preparation method of noble metal catalysts consists of the following steps: (1) A composite carrier was obtained by mixing foamed silicon carbide, carbon nanotubes and ZSM-5 molecular sieves at a mass ratio of 3:1:1; wherein the foamed silicon carbide consisted of spheres with a diameter of 8 mm, a pore size of 0.5~1.5 mm, and a specific surface area of 150 m². 2 / g; the outer diameter of the carbon nanotubes is 4~6mm, and the length is 0.5~2µm; (2) Weigh 0.5g of RuCl3 and dissolve it in deionized water. Transfer the solution to a 100mL volumetric flask and add deionized water to the corresponding mark to prepare a ruthenium chloride solution with a mass concentration of 5mg / mL. (3) The composite carrier obtained in step (1) is added to a ruthenium chloride solution and loaded at 50°C for 3 hours. Then it is filtered and dried to obtain a carrier loaded with the precursor. The mass ratio of the composite carrier to the volume ratio of the ruthenium precursor solution is 160 mg: 1 mL. (4) The carrier with precursor obtained in step (3) is calcined in a hydrogen atmosphere to obtain a noble metal catalyst; wherein the calcination temperature is 250°C and the calcination time is 2h.
[0045] Example 2 Based on Example 1, the molecular sieve was replaced with Silicalite-1 molecular sieve, which has a specific surface area of 405 m². 2 / g, pore volume is 0.51cm³ 3 / g, other conditions remain unchanged.
[0046] Example 3 Based on Example 1, the molecular sieve was changed to ZSM-5 molecular sieve and Silicalite-1 molecular sieve (with a specific surface area of 405 m²). 2 / g, pore volume is 0.51cm³ 3 / g), the mass ratio of ZSM-5 molecular sieve and Silicalite-1 molecular sieve is 1:3, and other conditions remain unchanged.
[0047] Example 4 Based on Example 1, the mass ratio of foamed silicon carbide, carbon nanotubes and molecular sieves was changed to 1:1:0.5, while other conditions remained unchanged.
[0048] Example 5 Based on Example 1, the mass ratio of foamed silicon carbide, carbon nanotubes and molecular sieves was changed to 5:2:3, while other conditions remained unchanged.
[0049] Comparative Example 1 Based on Example 1, the mass ratio of foamed silicon carbide, carbon nanotubes and molecular sieves was changed to 0.5:0.5:6, while other conditions remained unchanged.
[0050] Comparative Example 2 Based on Example 1, foamed silicon carbide was omitted, while other conditions remained unchanged.
[0051] Comparative Example 3 Based on Example 1, carbon nanotubes were omitted, while other conditions remained unchanged.
[0052] Comparative Example 4 Based on Example 1, the molecular sieve is omitted, while other conditions remain unchanged.
[0053] The noble metal catalysts prepared in Examples 1-5 and Comparative Examples 1-4 were applied to the catalytic conversion of butene to butadiene using water vapor, oxygen, or air. Their activity in the oxidative dehydrogenation of butene to butadiene was evaluated under the following conditions: reaction temperature 350°C, butene volume hourly space velocity 600 h⁻¹. -1The oxygen-to-olefin ratio (molar ratio of oxygen to butene) was 0.7, the water-to-olefin ratio (molar ratio of water to butene) was 8, and the butene conversion rate, butadiene selectivity, and stable operating time are shown in Table 1.
[0054] Table 1. Catalytic activity data of the noble metal catalysts prepared in Examples 1-5 and Comparative Examples 1-4.
[0055] As can be seen from Table 1, by limiting the mass ratio of foamed silicon carbide, carbon nanotubes and molecular sieves within the above range, the activity of the catalyst can be further improved; foamed silicon carbide, carbon nanotubes and molecular sieves can synergistically improve the activity and stability of the catalyst; ZSM-5 molecular sieve and Silicalite-1 molecular sieve can synergistically improve the activity and stability of the catalyst.
[0056] As can be seen from the above embodiments, the noble metal catalyst provided by the present invention has excellent catalytic activity and stability.
[0057] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A method for preparing a noble metal catalyst, comprising the following steps: (1) A composite carrier is obtained by mixing foamed silicon carbide, carbon nanotubes and molecular sieves; (2) The composite carrier obtained in step (1) is mixed with a ruthenium precursor solution and loaded to obtain a carrier loaded with the precursor; (3) The carrier loaded with precursor obtained in step (2) is calcined to obtain a noble metal catalyst.
2. The preparation method according to claim 1, characterized in that, The molecular sieve in step (1) includes ZSM-5 type molecular sieve and / or Silicalite-1 molecular sieve.
3. The preparation method according to claim 1, characterized in that, In step (1), the mass ratio of foamed silicon carbide, carbon nanotubes and molecular sieve is (1~5): (1~2); (0.5~3).
4. The preparation method according to claim 1, characterized in that, The concentration of the ruthenium precursor solution in step (2) is 5~10 mg / mL.
5. The preparation method according to claim 4, characterized in that, In step (2), the mass ratio of the composite carrier to the volume ratio of the ruthenium precursor solution is (150~200) mg: (1~2) mL.
6. The preparation method according to claim 1, characterized in that, In step (2), the temperature of the load is 50~60℃ and the loading time is 2~3h.
7. The preparation method according to claim 1, characterized in that, The roasting in step (3) is carried out in a hydrogen atmosphere.
8. The preparation method according to claim 1, characterized in that, The roasting temperature in step (3) is 100~600℃ and the roasting time is 1~5h.
9. The noble metal catalyst prepared by the preparation method according to any one of claims 1 to 8.
10. The application of the noble metal catalyst according to claim 9 in catalytic dehydrogenation.