A catalyst carrier prepared using pseudo-boehmite
By preparing a catalyst support using boehmite and employing silane hybridization and nickel nitrate loading, the problems of poor catalyst support stability and easy sintering of precious metals were solved, achieving high-efficiency catalytic performance and low-cost industrial application.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- YANGZHOU ZHONGTIANLI NEW MATERIAL
- Filing Date
- 2023-11-20
- Publication Date
- 2026-05-19
AI Technical Summary
Existing catalyst supports have poor stability, precious metals are prone to sintering, leading to excessive hydrogenation of aromatic rings, and are costly, making them difficult to promote and use in industry.
A catalyst support was prepared using boehmite, and the gel-state silica-alumina material was treated with silane hybridization to load the active component nickel nitrate. Combined with binders and functional additives, a highly efficient non-precious metal catalyst was formed.
It improves the catalyst's ability to load active components, reduces reaction conditions, achieves higher product conversion rates and lowers production costs, making it suitable for large-scale industrial production.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of molecular sieve catalyst technology, and in particular to a catalyst support prepared using boehmite and its preparation method. Background Technology
[0002] Vanillin (3-methoxy-4-hydroxybenzaldehyde), a natural phenolic compound, can be obtained in large quantities from industrial lignin and has long been considered a typical lignin model compound and one of the most promising renewable lignin-derived platform compounds. Among them, 2-methoxy-4-methylphenol (MMP), obtained from vanillin via hydrodeoxygenation, is an important pharmaceutical and pesticide intermediate and also a promising biomass fuel. Therefore, research on the hydrogenation-deoxygenation (HDO) reaction of vanillin is of great significance for the value-added processing of lignin-based biomass resources.
[0003] Highly efficient catalysts are crucial for ensuring effective hydrodeoxygenation. To achieve green and environmentally friendly goals, heterogeneous catalytic materials are generally used. Therefore, developing more efficient heterogeneous catalysts is of great significance. The active substances on the catalyst surface play a decisive role in the reaction performance of heterogeneous catalysis. Examples include noble metals Ru, Pd, and Pt supported on various supports. While noble metal catalysts can promote lignin conversion, they inevitably lead to excessive hydrogenation of aromatic rings, forming fully saturated hydrocarbons under high hydrogen consumption. Moreover, noble metals are expensive, making their industrial application difficult. Therefore, using non-noble metal catalysts is more economical and has greater practical application value. On the other hand, the support is also an indispensable part of the catalyst. Acidic sites in the catalyst can promote the hydrodeoxygenation of the feedstock. Furthermore, it can promote metal dispersion, and strong metal-support interactions can prevent metal agglomeration and sintering during lignin conversion. Currently, most catalysts use activated carbon, metal oxides, or zeolites as supports, which suffer from poor support stability and easy sintering and detachment of active metals.
[0004] Based on the above, the present invention proposes a method for preparing a catalyst support using boehmite. Summary of the Invention
[0005] The purpose of this invention is to provide a catalyst support prepared using boehmite and its preparation method.
[0006] To achieve the above objectives, the present invention provides a catalyst support prepared using boehmite, wherein the catalyst support is prepared by the following steps:
[0007] (1) Dry boehmite at a temperature of 100-105℃ for 10-12 hours, then add it to a nitric acid solution and stir to form a suspension. The molar ratio of the boehmite to the proton hydrogen in the nitric acid solution is 0.18:1.
[0008] (2) Add tetraethyl orthosilicate to the suspension in step (1) at a mass ratio of 3:1 between boehmite and tetraethyl orthosilicate, stir for 15 to 20 minutes at 400 to 500 r / min, filter and dry until the water content is 50% to obtain gel-state aluminosilicate material.
[0009] (3) Dissolve the gelled silicon-aluminum material in ultrapure water at a material-liquid ratio of 1g:50~55ml to form a gel aqueous solution. Then add nickel nitrate and polyvinylpyrrolidone to the gel aqueous solution and stir evenly. The mass ratio of nickel nitrate, polyvinylpyrrolidone and gelled silicon-aluminum material is 3:1:8.
[0010] (4) Weigh NaBH4 according to the molar ratio of NaBH4 to nickel nitrate of 10:1, dissolve NaBH4 in ultrapure water according to the material-liquid ratio of 1g:30~35ml, and add the NaBH4 solution to the gel aqueous solution obtained in step (3) at 2~3 drops per second after complete dissolution. Continue stirring for 1~2h, then filter and wash the solid until neutral to obtain the catalyst precursor.
[0011] (5) The catalyst precursor obtained in step (4) is mixed with binder and functional additive, dried at 120°C for 6 hours and calcined at 900°C for 3 hours to obtain catalyst support.
[0012] Preferably, the binder is one of aluminum nitrate, aluminum sulfate, aluminum chloride, aluminum hydroxide, sodium aluminate, boehmite, and aluminum isopropoxide.
[0013] Preferably, the functional additive is selected from one or more of starch, guar gum powder, hydroxyethyl methylcellulose, methylcellulose, and polyethylene glycol.
[0014] Preferably, the mass ratio of the binder to the catalyst precursor is 1:10, and the mass ratio of the functional additive to the catalyst precursor is 1:25.
[0015] Preferably, the gel-state silicon-aluminum material undergoes silane hybridization treatment.
[0016] Preferably, the silane-hybridized gel-state silicon-aluminum material is prepared by the following method: a methanol suspension is formed by mixing 1g (gel-state silicon-aluminum material) with 50-60ml (methanol) by mass ratio, and then an organosilane is added to the methanol suspension at a mass ratio of 1g (gel-state silicon-aluminum material) with 30-40ml (organosilane) and mixed evenly. The mixture is stirred at 25-30°C for 24 h, filtered, and the filter residue is washed three times with anhydrous ethanol, centrifuged, and vacuum dried for 12 h to obtain the silane-hybridized gel-state silicon-aluminum material.
[0017] Preferably, the organosilane is an organosilane containing a trimethoxy structure.
[0018] Preferably, the organosilane containing the trimethoxy structure is one of phenyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-chloropropyltrimethoxysilane, and vinyltrimethoxysilane.
[0019] Preferably, the organosilane containing the trimethoxy structure is 3-chloropropyltrimethoxysilane.
[0020] The present invention also provides the use of the catalyst support described herein in the preparation of 2-methoxy-4-methylphenol using vanillin as a raw material.
[0021] Compared with the prior art, the present invention has the following beneficial effects:
[0022] 1. The catalyst support prepared by this invention selects a suitable type of organosilane during the formation of the catalyst support and hybridizes the gel-state silica-alumina material with organosilane, which greatly improves its ability to load the active reactive component nickel nitrate, thereby reducing the required reaction conditions and enabling the reaction to achieve a higher product conversion rate under lower pressure, temperature and catalyst dosage conditions.
[0023] 2. The raw materials for this invention are readily available and reasonably priced in China, which means that there are no high cost restrictions on its large-scale production. At the same time, the preparation method is simple and the overall production cost is not high, which is conducive to large-scale industrial production. Detailed Implementation
[0024] Example 1
[0025] The preparation steps are as follows:
[0026] (1) Dry boehmite at 100°C for 12 hours, then add it to nitric acid solution and stir to form a suspension. The molar ratio of the boehmite to the proton hydrogen in the nitric acid solution is 0.18:1.
[0027] (2) Add tetraethyl orthosilicate to the suspension in step (1) at a mass ratio of 3:1 between boehmite and tetraethyl orthosilicate, stir for 20 min at 400 r / min, filter and dry until the water content is 50% to obtain gel-state aluminosilicate material.
[0028] (3) Mix 1g (gel-like silicon-aluminum material) : 50ml (methanol) to form a methanol suspension. Then add organosilane to the methanol suspension at a mass ratio of 1g (gel-like silicon-aluminum material) : 30ml (3-chloropropyltrimethoxysilane) and mix well. Stir at 25°C for 24 h, filter, wash the filter residue with anhydrous ethanol 3 times, centrifuge, and vacuum dry for 12 h to obtain silane-hybridized gel-like silicon-aluminum material.
[0029] (4) Dissolve the silane-hybridized gel-state aluminum silicate material in ultrapure water at a material-liquid ratio of 1g:50ml to form a gel aqueous solution. Then add nickel nitrate and polyvinylpyrrolidone to the gel aqueous solution and stir evenly. The mass ratio of nickel nitrate, polyvinylpyrrolidone and silane-hybridized aluminum silicate material is 3:1:6.
[0030] (5) Weigh NaBH4 according to the molar ratio of NaBH4 to nickel nitrate of 10:1, dissolve NaBH4 in ultrapure water according to the material-liquid ratio of 1g:30ml, and add the NaBH4 solution to the gel aqueous solution obtained in step (4) at 2~3 drops per second after complete dissolution. Continue stirring for 1h, then filter and wash the solid until neutral to obtain the catalyst precursor.
[0031] (6) The catalyst precursor obtained in step (4) is mixed with aluminum isopropoxide, hydroxyethyl methyl cellulose and polyethylene glycol, dried at 120°C for 6 hours and calcined at 900°C for 3 hours to obtain the catalyst support.
[0032] The mass ratio of aluminum isopropoxide to the catalyst precursor is 1:10, and the mass ratio of hydroxyethyl methyl cellulose, polyethylene glycol, etc., after being mixed, to the catalyst precursor is 1:25.
[0033] Example 2
[0034] The preparation steps are as follows:
[0035] (1) Dry boehmite at 105°C for 10 hours, then add it to a nitric acid solution and stir to form a suspension. The molar ratio of the boehmite to the proton hydrogen in the nitric acid solution is 0.2:1.
[0036] (2) Add tetraethyl orthosilicate to the suspension in step (1) at a mass ratio of 3:1 between boehmite and tetraethyl orthosilicate, stir for 15 min at 500 r / min, filter and dry until the water content is 50% to obtain gel-state aluminosilicate material.
[0037] (3) Mix 1g (gel-like silicon-aluminum material) : 60ml (methanol) to form a methanol suspension. Then add organosilane to the methanol suspension at a mass ratio of 1g (gel-like silicon-aluminum material) : 40ml (3-chloropropyltrimethoxysilane) and mix well. Stir at 30℃ for 24 h, filter, wash the filter residue with anhydrous ethanol 3 times, centrifuge, and vacuum dry for 12 h to obtain silane-hybridized gel-like silicon-aluminum material.
[0038] (4) The silane-hybridized gel-state silicon-aluminum material is dissolved in ultrapure water at a material-liquid ratio of 1g: 55ml to form a gel aqueous solution. Then, nickel nitrate and polyvinylpyrrolidone are added to the gel aqueous solution and stirred evenly. The mass ratio of nickel nitrate, polyvinylpyrrolidone and silane-hybridized gel-state silicon-aluminum material is 3:1:7.
[0039] (5) Weigh NaBH4 according to the molar ratio of NaBH4 to nickel nitrate of 10:1, dissolve NaBH4 in ultrapure water according to the material-liquid ratio of 1g: 35ml, and add the NaBH4 solution to the gel aqueous solution obtained in step (4) at 2~3 drops per second after complete dissolution. Continue stirring for 2h, then filter and wash the solid until neutral to obtain the catalyst precursor.
[0040] (6) The catalyst precursor obtained in step (4) is mixed with aluminum isopropoxide, hydroxyethyl methyl cellulose and polyethylene glycol, dried at 125°C for 6 hours and calcined at 910°C for 3 hours to obtain the catalyst support.
[0041] The mass ratio of aluminum isopropoxide to the catalyst precursor is 1:10, and the mass ratio of hydroxyethyl methyl cellulose, polyethylene glycol, etc., after being mixed, to the catalyst precursor is 1:25.
[0042] Example 3
[0043] The preparation steps are as follows:
[0044] (1) Dry boehmite at 105°C for 10 hours, then add it to a nitric acid solution and stir to form a suspension. The molar ratio of the boehmite to the proton hydrogen in the nitric acid solution is 0.2:1.
[0045] (2) Add tetraethyl orthosilicate to the suspension in step (1) at a mass ratio of 3:1 between boehmite and tetraethyl orthosilicate, stir at 500 r / min for 20 min, filter and dry to a water content of 50% to obtain gel-state aluminosilicate material;
[0046] (3) Mix 1g (gel-like silicon-aluminum material) : 55ml (methanol) to form a methanol suspension. Then add organosilane to the methanol suspension at a mass ratio of 1g (gel-like silicon-aluminum material) : 35ml (3-chloropropyltrimethoxysilane) and mix well. Stir at 30℃ for 24 h, filter, wash the filter residue with anhydrous ethanol 3 times, centrifuge, and vacuum dry for 12 h to obtain silane-hybridized gel-like silicon-aluminum material.
[0047] (4) The silane-hybridized gel-state silicon-aluminum material is dissolved in ultrapure water at a material-liquid ratio of 1g: 55ml to form a gel aqueous solution. Then, nickel nitrate and polyvinylpyrrolidone are added to the gel aqueous solution and stirred evenly. The mass ratio of nickel nitrate, polyvinylpyrrolidone and silane-hybridized gel-state silicon-aluminum material is 3:1:7.
[0048] (5) Weigh NaBH4 according to the molar ratio of NaBH4 to nickel nitrate of 10:1, dissolve NaBH4 in ultrapure water according to the material-liquid ratio of 1g: 35ml, and add the NaBH4 solution to the gel aqueous solution obtained in step (4) at 2~3 drops per second after complete dissolution. Continue stirring for 2h, then filter and wash the solid until neutral to obtain the catalyst precursor.
[0049] (6) The catalyst precursor obtained in step (4) is mixed with aluminum isopropoxide, hydroxyethyl methyl cellulose and polyethylene glycol, dried at 125°C for 6 hours and calcined at 910°C for 3 hours to obtain the catalyst support.
[0050] The mass ratio of aluminum isopropoxide to the catalyst precursor is 1:10, and the mass ratio of hydroxyethyl methyl cellulose, polyethylene glycol, etc., after being mixed, to the catalyst precursor is 1:25.
[0051] Comparative Example 1
[0052] Unlike Example 3, the non-gelled silicon-aluminum material undergoes silane hybridization treatment, i.e., step (4) is omitted, and the remaining steps are the same as in Example 3.
[0053] Comparative Example 2
[0054] The difference from Example 3 is that the organosilane is phenyltrimethoxysilane, and the remaining steps are the same as in Example 3.
[0055] Comparative Example 3
[0056] The difference from Example 3 is that the organosilane is vinyltrimethoxysilane, and the remaining steps are the same as in Example 3.
[0057] Comparative Example 4
[0058] The difference from Example 3 is that the organosilane is 3-aminopropyltrimethoxysilane, and the remaining steps are the same as in Example 3.
[0059] Example 4 Evaluation of the synthesis of N-methylmorpholine catalyzed by p-morpholine and methanol
[0060] The prepared samples from Examples 1-3 and Comparative Examples 1-4 were used in the hydrogenation deoxygenation reaction of vanillin to prepare 2-methoxy-4-methylphenol (MMP). A high-pressure reactor was used, the reaction atmosphere was high-purity nitrogen, the amount of vanillin was 0.5 g, the solvent was ethanol, and the reaction time was 2.5 h. The conversion efficiency results are shown in Tables 2-4. Specifically, Table 2 shows the effect of 200℃ on vanillin conversion and 2-methoxy-4-methylphenol selectivity when the catalyst dosage was 2.5 g and the initial pressure was 1.0 MPa; Table 3 shows the effect of 220℃ on vanillin conversion and 2-methoxy-4-methylphenol selectivity when the catalyst dosage was 2.5 g and the initial pressure was 0.3 MPa; and Table 4 shows the effect of 220℃ on vanillin conversion and 2-methoxy-4-methylphenol selectivity when the catalyst dosage was 1.0 g and the initial pressure was 1.0 MPa.
[0061] Table 2
[0062]
[0063] Table 3
[0064]
[0065] Table 4
[0066]
[0067] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.
Claims
1. A catalyst support prepared using boehmite, characterized in that, The catalyst support is prepared by the following steps: (1) Dry boehmite at a temperature of 100-105℃ for 10-12 hours, then add it to a nitric acid solution and stir to form a suspension. The molar ratio of the boehmite to the proton hydrogen in the nitric acid solution is 0.18:
1. (2) Add tetraethyl orthosilicate to the suspension in step (1) at a mass ratio of 3:1 between boehmite and tetraethyl orthosilicate, stir for 15 to 20 minutes at 400 to 500 r / min, filter and dry until the water content is 50% to obtain gel-state aluminosilicate material. (3) Dissolve the silane-hybridized gel-state silicon-aluminum material in ultrapure water at a material-liquid ratio of 1g:50~55mL to form a gel aqueous solution. Then add nickel nitrate and polyvinylpyrrolidone to the gel aqueous solution and stir evenly. The mass ratio of nickel nitrate, polyvinylpyrrolidone and silane-hybridized gel-state silicon-aluminum material is 3:1:
8. (4) Weigh NaBH4 according to the molar ratio of NaBH4 to nickel nitrate of 10:1, dissolve NaBH4 in ultrapure water according to the material-liquid ratio of 1g:30~35mL, and add the NaBH4 solution to the gel aqueous solution obtained in step (3) at 2~3 drops per second after complete dissolution. Continue stirring for 1~2h, then filter and wash the solid until neutral to obtain the catalyst precursor. (5) The catalyst precursor obtained in step (4) is mixed with binder and functional additive, dried at 120°C for 6 hours and calcined at 900°C for 3 hours to obtain catalyst support; The gel-state silicon-aluminum material undergoes silane hybridization treatment, the specific steps of which are as follows: A methanol suspension was formed by mixing 1g of gel-state aluminosilicate material with 50-60mL of methanol. Then, organosilane was added to the methanol suspension with 1g of gel-state aluminosilicate material and 30-40mL of organosilane. The mixture was stirred at 25-30℃ for 24 h, filtered, and the filter residue was washed three times with anhydrous ethanol. The residue was then centrifuged and vacuum dried for 12 h to obtain the silane-hybridized gel-state aluminosilicate material. The organosilane is 3-chloropropyltrimethoxysilane.
2. The catalyst support according to claim 1, characterized in that, The binder is one of aluminum nitrate, aluminum sulfate, aluminum chloride, aluminum hydroxide, sodium aluminate, boehmite, or aluminum isopropoxide.
3. The catalyst support according to claim 1, characterized in that, The functional additives are selected from one or more of starch, guar gum powder, hydroxyethyl methylcellulose, methylcellulose, and polyethylene glycol.
4. The catalyst support according to claim 2 or 3, characterized in that, The mass ratio of the binder to the catalyst precursor is 1:10, and the mass ratio of the functional additive to the catalyst precursor is 1:
25.
5. The use of a catalyst support in the preparation of 2-methoxy-4-methylphenol from vanillin, characterized in that, The catalyst support is the catalyst support according to any one of claims 1-4.