A catalyst for synthesizing 1,2,3,4-tetrahydronaphthol and preparation and application thereof

Abstract

This invention belongs to the field of heterogeneous hydrogenation catalyst technology, specifically relating to a catalyst for the synthesis of 1,2,3,4-tetrahydronaphthol, its preparation, and its application. The catalyst comprises the following components by weight percentage: 75-90% activated carbon, 5-15% aluminate, and 5-15% active metal; the aluminate is sodium aluminate or potassium aluminate; the active metal is nickel. The catalyst of this invention possesses abundant alkali metal cations (basic centers), which can effectively modulate the adsorption configuration of reactant molecules on the catalyst surface, while simultaneously improving the tautomerism of the reactants. Furthermore, the active metal nickel exhibits high dispersibility. Therefore, it demonstrates high reactivity, selectivity, and stability in the hydrogenation preparation of 1,2,3,4-tetrahydronaphthol.

Description

Technical Field

[0001] This invention belongs to the field of heterogeneous hydrogenation catalyst technology, specifically relating to a catalyst for the synthesis of 1,2,3,4-tetrahydronaphthol, its preparation, and its application. Background Technology

[0002] 1,2,3,4-Tetrahydronaphthol is an effective hydrogen donor that can effectively delay the formation of carbonaceous substances in jet fuel. It is a high-performance high-temperature stabilizer for jet fuel and is also widely used in the field of organic synthesis as an abundant chemical raw material.

[0003] 1,2,3,4-Tetrahydronaphthol is mainly prepared from 2-naphthol via a high-pressure hydrogenation reaction. Regarding homogeneous catalyst research, Li et al., under conditions of 443 K, 650 psi hydrogen pressure, and 72 h reaction time, used Ru-PN containing a phenanthroline skeleton... 3 Using the complex as a homogeneous catalyst, the hydrogenation of 2-naphthol to 1,2,3,4-tetrahydro-2-naphthol was achieved in 79% yield (ACScatalysis, 2017, 7, 4446-4450). Furthermore, Yasuko Kamochi et al., under alkaline conditions and containing a protonated solvent of tetrahydrofuran, mixed 2-naphthol with 6 equivalents of SmI2 at room temperature, and after continuous stirring for 6 min, achieved a 95% yield of 1,2,3,4-tetrahydro-2-naphthol (Tetrahedron Letters, 1994, 35(24), 4169-4172).

[0004] However, homogeneous catalysts suffer from difficulties in separation and high costs. In the study of heterogeneous hydrogenation catalysts, Gilbert Stork used Raney nickel as a catalyst to carry out the selective hydrogenation of 2-naphthol. The yield of 1,2,3,4-tetrahydro-2-naphthol was 41% after 2 h of reaction at 85 °C. The addition of 40% sodium hydroxide to the reaction system can significantly improve the selectivity of 1,2,3,4-tetrahydro-2-naphthol, but the base in the product needs to be further separated after the reaction to obtain the product 1,2,3,4-tetrahydronaphthol (Journal of the American Chemical Society, 1947, 69(3):576-579). BC GATES et al. prepared a hydrogenation catalyst using Ni-Mo and Co-Mo as active components and γ-Al2O3 as support for the hydrogenation of naphthol. The results showed that the catalyst had low activity and poor selectivity, and needed to be carried out at a high temperature (200 °C) (AIChEJournal.1985, 31(1), 170-174). Noble metal catalysts exhibit higher catalytic activity. For example, Shao et al. prepared a Pt–Pd / TiO2 catalyst using TiO2 as a support and a Pt-Pd bimetallic system as the active component. This catalyst showed high catalytic activity and achieved complete conversion of naphthol at 150 °C. However, its selectivity was poor, below 25% (Catalysis Today 65 (2001) 59–67). Masayuki Shirai, using supercritical carbon dioxide as a system and metal catalysts such as Rh / C and Rh / Al2O3, achieved a selectivity of 50% for tetrahydronaphthol reduction (Catalyst Today 2006, 115, 248-253). Similarly, Eiichi Mine et al. studied the hydrogenation of naphthol under supercritical CO2 conditions at 323 K, using 5 wt% Rh / C as a catalyst. The results showed that after 2 h, the naphthol conversion was 90%, and the selectivity for tetrahydronaphthol was 70% (Chemistry Letters Vol.34, No.6 (2005), 782-783). The techniques described above require strong conditions for selective hydrogenation of naphthol derivatives to achieve high yields of the target product. These conditions involve high synthesis temperatures and long reaction times. Under high-temperature alkaline conditions, Raney nickel catalysts can collapse and deactivate due to dealuminization, and replacing the catalyst also presents certain safety concerns. Supported metal catalysts suffer from harsh reaction conditions, poor catalyst activity, high cost, and low product selectivity. While homogeneous catalysts can improve the selectivity and yield of naphthol hydrogenation to tetrahydronaphthol, they inevitably suffer from high cost and difficulty in separating the catalyst from the product. Summary of the Invention

[0005] This invention addresses the problems of easy catalyst deactivation, poor selectivity, high cost, and difficult product separation in existing technologies by providing a highly active and selective non-precious metal catalyst. This catalyst can still exhibit high activity and selectivity under conditions without liquid alkali, and at the same time, no further product separation is required.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A catalyst for synthesizing 1,2,3,4-tetrahydronaphthol, the catalyst comprising the following components in weight percentage: 75-90% activated carbon, 5-15% aluminate, and 5-15% active metal; wherein the aluminate is sodium aluminate or potassium aluminate, and the active metal is nickel.

[0007] Preferably, the catalyst comprises the following components, by weight percentage: 75-90% activated carbon, 5-10% aluminate, and 5-15% active metal.

[0008] The catalyst has a specific surface area of ​​500-800 m². 2 / g, total pore volume is 0.6-1.0cm³ 3 / g.

[0009] The activated carbon has a specific surface area of ​​1000-1500 m². 2 / g, pore volume 0.9-1.2 cm³ 3 / g.

[0010] A method for preparing the catalyst for synthesizing 1,2,3,4-tetrahydronaphthol involves mixing activated carbon with an active metal salt solution, adding sodium hydroxide solution, impregnating the mixture, filtering, washing with water until the pH is neutral, drying and calcining the sample, mixing the calcined solid sample with aluminum hydroxide and water, and adding a solid base under stirring conditions. The mixture is then rotary evaporated to obtain a dry solid, which is washed with hot ethanol, dried, and then reduced under a hydrogen / argon mixed gas to obtain the catalyst.

[0011] Specifically, activated carbon is mixed with an active metal salt solution, stirred, and sodium hydroxide solution is slowly added dropwise. After impregnation, the mixture is filtered, washed with water until the pH is neutral, dried, and calcined under nitrogen protection. The calcined solid sample, aluminum hydroxide, and water are mixed in a three-necked flask, and a solid alkali is slowly added while stirring. The mixture is heated to a higher temperature to react. The mixture is then rotary evaporated to obtain a dry solid. The solid is washed with hot ethanol, dried, and then reduced under a hydrogen / argon mixture to obtain the catalyst.

[0012] The active metal salt is one or more of nickel nitrate hexahydrate, nickel chloride hexahydrate, and nickel sulfate hexahydrate. The mass ratio of the metal to activated carbon in the metal salt is 0.05-0.15.

[0013] The calcination temperature is 450-650℃. The solid alkali is one or both of sodium hydroxide and potassium hydroxide, and the molar ratio of the solid alkali to aluminum hydroxide is 1.95-2:1.

[0014] After adding solid alkali, heat to 80-100℃ to react, and the mixture is rotary evaporated at 60-70℃.

[0015] The reduction temperature is 300-450℃, and the hydrogen volume concentration in the hydrogen / argon mixture is 5%.

[0016] Application of the catalyst for the synthesis of 1,2,3,4-tetrahydronaphthol, specifically its application in the selective hydrogenation synthesis of 1,2,3,4-tetrahydronaphthol.

[0017] The catalyst is supported in situ with alkali metal cations, which synergistically interact with the active metal to regulate the adsorption configuration of reactant molecules on the catalyst surface and enhance the tautomerism of alcohols and ketones in the reactants, thereby improving the selectivity for synthesizing 1,2,3,4-tetrahydronaphthol.

[0018] The reactant is 2-naphthol or 1-naphthol.

[0019] A specific method for synthesizing 1,2,3,4-tetrahydronaphthol is as follows: The catalyst and the 2-naphthol / isopropanol mixture were added to a high-pressure hydrogenation reactor. After the gas in the reactor was replaced with hydrogen / argon, the system pressure was increased to 3.0 MPa, stirring was started and the reaction temperature was increased to 80°C. The reaction time was 6 hours.

[0020] The mass ratio of the catalyst to the 2-naphthol / isopropanol mixture is 1:8, and the mass fraction of 2-naphthol is 10%.

[0021] This invention patent has the following advantages: 1. The catalyst of this invention has abundant alkali metal cations (basic centers), which can effectively modulate the adsorption configuration of reactant molecules on the catalyst surface and improve the tautomerism of alcohol and ketone structures of the reactants. At the same time, the active metal nickel has high dispersibility. Therefore, it has high reactivity, selectivity and stability in the hydrogenation preparation of 1,2,3,4-tetrahydronaphthol.

[0022] 2. The catalyst of this invention has high safety in use, is easy to separate and recover, and is suitable for industrial production.

[0023] 3. The catalyst of this invention can be used in the selective hydrogenation of various naphthalene derivatives, such as the selective hydrogenation of 1-naphthol, 1-methoxynaphthalene, and 2-methoxynaphthalene. Attached Figure Description

[0024] Figure 1This is a TEM image of the catalyst in Example 1.

[0025] Figure 2 This is a SEM image of the catalyst from Example 1.

[0026] Figure 3 This is the EDS elemental analysis diagram of the catalyst in Example 1. Detailed Implementation

[0027] The technical features of the present invention are further described below through embodiments, but are not limited to these embodiments.

[0028] This invention prepares a highly dispersed nickel catalyst and immobilizes basic centers in situ, which synergistically interact with active nickel to regulate the adsorption configuration of reactant molecules on the catalyst surface and improve the tautomerization of alcohols and ketones in the reactants. It exhibits high reactivity and selectivity in the selective hydrogenation of naphthol to synthesize 1,2,3,4-tetrahydronaphthol, is highly safe to use, easy to separate and recover, and is suitable for industrial production.

[0029] Example 1 5g of activated carbon (industrial grade) was mixed with 20ml of a 126 g / L nickel nitrate hexahydrate (98wt%) solution (10% Ni). A 0.5mol / L sodium hydroxide solution was slowly added dropwise under stirring until the pH reached 8. Stirring was continued at 30℃ for 8 hours. The mixture was filtered and washed with water until the filtrate pH was neutral. The solid sample was dried at 120℃ for 8 hours and then calcined at 550℃ for 4 hours under nitrogen. The calcined solid sample was mixed with 1g of aluminum hydroxide and 20g of water in a three-necked flask. 1g of sodium hydroxide was slowly added under vigorous stirring. The mixture was heated to 80℃ and reacted for 2 hours. The mixture was dried by rotary evaporation at 60℃ to obtain a solid powder (10% NaAlO2). The solid powder was washed with hot ethanol, dried at 100℃ for 12 hours, and then reduced with 5% H2 / Ar hydrogen at 300℃ for 4 hours to obtain the catalyst, named C-1.

[0030] Example 2 5g of activated carbon (industrial grade) was mixed with 20ml of a 64g / L nickel nitrate hexahydrate (98wt%) solution (5% Ni). A 0.5mol / L sodium hydroxide solution was slowly added dropwise under stirring until the pH reached 8. Stirring was continued at 30℃ for 8h. The mixture was filtered and washed with water until the filtrate pH was neutral. The solid sample was dried at 120℃ for 8h and then calcined at 550℃ for 4h under nitrogen. The calcined solid sample was mixed with 0.5g of aluminum hydroxide and 20g of water in a three-necked flask. 0.5g of sodium hydroxide was slowly added under vigorous stirring. The mixture was heated to 80℃ and reacted for 2h. The mixture was dried by rotary evaporation at 60℃ to obtain a solid powder (5% NaAlO2). The solid powder was washed with hot ethanol, dried at 100℃ for 12h, and then reduced with 5% H2 / Ar hydrogen at 400℃ for 4h to obtain the catalyst, named C-2.

[0031] Example 3 5g of activated carbon (industrial grade) was mixed with 20ml of a 192 g / L nickel nitrate hexahydrate (98wt%) solution (15% Ni). A 0.5mol / L sodium hydroxide solution was slowly added dropwise under stirring until the pH reached 8. Stirring was continued at 30℃ for 8 hours. The mixture was filtered and washed with water until the filtrate pH was neutral. The solid sample was dried at 120℃ for 8 hours and then calcined at 450℃ for 4 hours under nitrogen. The calcined solid sample was mixed with 0.5g of aluminum hydroxide and 20g of water in a three-necked flask. 0.72g of potassium hydroxide was slowly added under vigorous stirring. The mixture was heated to 90℃ and reacted for 2 hours. The mixture was dried by rotary evaporation at 70℃ to obtain a solid powder (5% KAlO2). The solid powder was washed with hot ethanol, dried at 100℃ for 12 hours, and then reduced with 5% H2 / Ar hydrogen at 400℃ for 4 hours to obtain the catalyst, named C-3.

[0032] Example 4 5g of activated carbon (industrial grade) was mixed with 20ml of a 126 g / L nickel nitrate hexahydrate (98wt%) solution (10% Ni). A 0.5mol / L sodium hydroxide solution was slowly added dropwise under stirring until the pH reached 8. Stirring was continued at 30℃ for 8 hours. The mixture was filtered and washed with water until the filtrate pH was neutral. The solid sample was dried at 120℃ for 8 hours and then calcined at 650℃ for 4 hours under nitrogen. The calcined solid sample was mixed with 0.75g of aluminum hydroxide and 20g of water in a three-necked flask. 0.75g of sodium hydroxide was slowly added under vigorous stirring. The mixture was heated to 100℃ and reacted for 2 hours. The mixture was dried by rotary evaporation at 70℃ to obtain a solid powder (7.5% NaAlO2). The solid powder was washed with hot ethanol, dried at 100℃ for 12 hours, and then reduced with 5% H2 / Ar hydrogen at 450℃ for 4 hours to obtain the catalyst, named C-4.

[0033] Example 5 The difference from Example 1 is that the active metal salt was replaced with nickel sulfate hexahydrate, while the other conditions were the same as in Example 1, resulting in a catalyst designated C-5.

[0034] Table 1. Catalyst properties and composition data for the examples

[0035] Comparative Example 1 The difference from Example 1 is that the catalyst preparation process does not involve the immobilization of basic centers; that is, the calcined solid sample is directly mixed with water without the addition of sodium hydroxide. Other conditions are the same as in Example 1, and the resulting catalyst is designated B-1.

[0036] Comparative Example 2 A commercial Raney nickel catalyst was selected, designated B-2.

[0037] Comparative Example 3 The difference from Example 1 is that the solid sample was dried at 120°C for 8 hours and then calcined at 550°C for 4 hours under nitrogen. Instead of supporting aluminate, it was directly reduced at 300°C for 4 hours using hydrogen with a concentration of 5% H2 / Ar to obtain the catalyst, which was named B-3.

[0038] Comparative Example 4 The difference from Example 1 is that the calcined solid sample was mixed with 2g of aluminum hydroxide and 20g of water in a three-necked flask, and 2g of sodium hydroxide was slowly added under vigorous stirring. The mixture was heated to 80°C and reacted for 2 hours. The mixture was dried by rotary evaporation at 60°C to obtain a solid powder (20% NaAlO2). The solid powder was washed with hot ethanol, dried at 100°C for 12 hours, and then reduced with hydrogen gas at a concentration of 5% H2 / Ar at 300°C for 4 hours to obtain a catalyst, named B-4.

[0039] Comparative Example 5 The difference from Example 1 is that the active metal salt was replaced with cobalt nitrate hexahydrate (98wt%), and the other conditions were the same as in Example 1, resulting in a catalyst designated B-5.

[0040] Application Example 1 1,2,3,4-Tetrahydro-2-naphthol was prepared by selective hydrogenation using 2-naphthol as a reactant. The catalytic performance of the above examples, comparative examples, and commercial catalysts was compared.

[0041] The evaluation criteria are as follows: In the examples and comparative examples, the mass ratio of catalyst (Ni metal mass) to reactant was 1:50, and the mass ratio of commercial catalyst Raney nickel to reactant was 1:8. The reaction was carried out in a 100 mL high-pressure hydrogenation reactor at a temperature of 80°C, a rotation speed of 950 r / min, a hydrogen pressure of 3.0 MPa, and a reaction time of 6 h. The reaction system was a mixture of reactant and isopropanol, with a reactant mass fraction of 10%.

[0042] Conversion rate: The target product, by-products and raw materials were analyzed by gas chromatography area normalization method.

[0043]

[0044] Selectivity:

[0045] Table 2 Catalyst Evaluation Data for Examples and Comparative Examples

[0046] As shown in Table 2, under the same evaluation conditions, when the catalyst was used once, the conversion rate of 2-naphthol hydrogenation by the catalyst of this invention reached 100%, and the selectivity of 1,2,3,4-tetrahydro-2-naphthol product was above 77.5%. In contrast, although the conversion rate of catalyst B-1 in Comparative Example 1 was 100%, the selectivity of 1,2,3,4-tetrahydro-2-naphthol product was poor, only 27.9%. The conversion rate of commercial Raney nickel catalyst B-2 in Comparative Example 2 was only 77.3%, and the selectivity of 1,2,3,4-tetrahydro-2-naphthol product was below 36%. The conversion rate of catalyst B-5 in Comparative Example 5 was only 63.2%. After four uses of the catalyst, the catalyst of this invention still maintains a conversion rate of 100% and a selectivity of over 77.4%, while the selectivity of Comparative Example 1 catalyst B-1 and Comparative Example 3 catalyst B-3 is poor, at only 28.4% and 31.2% respectively. The conversion rate of Comparative Example 2 commercial Raney nickel catalyst B-2 is 58.3%, and the product selectivity of 1,2,3,4-tetrahydro-2-naphthol is 35.2%. The conversion rate of Comparative Example 5 catalyst B-5 is only 62.3%. Therefore, the catalyst prepared by this invention has higher activity, selectivity and stability in the selective hydrogenation of 2-naphthol to prepare 1,2,3,4-tetrahydro-2-naphthol.

[0047] Application Example 2 1-Naphthol was selectively hydrogenated to prepare 1,2,3,4-tetrahydro-1-naphthol. The catalytic performance of the above examples, comparative examples, and commercial catalysts was evaluated under the same evaluation conditions.

[0048] The evaluation criteria are as follows: In the examples and comparative examples, the mass ratio of catalyst (Ni metal mass) to reactant was 1:50, and the mass ratio of commercial catalyst Raney nickel to reactant was 1:8. The reaction was carried out in a 100 mL high-pressure hydrogenation reactor at a temperature of 80°C, a rotation speed of 950 r / min, a hydrogen pressure of 3.0 MPa, and a reaction time of 6 h. The reaction system was a mixture of reactant and isopropanol, with a reactant mass fraction of 10%.

[0049] Conversion rate: The target product, by-products and raw materials were analyzed by gas chromatography area normalization method.

[0050]

[0051] Selectivity:

[0052] Table 3 Catalyst Evaluation Data for Examples and Comparative Examples

[0053] As shown in Table 3, under the same evaluation conditions, after one use of the catalyst, the conversion rate of the 1-naphthol hydrogenation reaction of the catalyst of the present invention reached 100%, and the selectivity of the 1,2,3,4-tetrahydro-1-naphthol product was above 77.8%. In contrast, although the conversion rate of catalyst B-1 in Comparative Example 1 was 100%, the selectivity of the 1,2,3,4-tetrahydro-1-naphthol product was poor, only 29.3%. The conversion rate of commercial Raney nickel catalyst B-2 in Comparative Example 2 was only 79.3%, and the selectivity of the 1,2,3,4-tetrahydro-1-naphthol product was below 38%. After four uses of the catalyst, the present invention… The catalyst still maintains 100% conversion and selectivity of over 77.6%, while the selectivity of Comparative Example 1 catalyst B-1 and Comparative Example 3 catalyst B-3 is poor, at only 29.4% and 33.7% respectively. Comparative Example 2, the commercial Raney nickel catalyst B-2, has a conversion of 56.4% and a 1,2,3,4-tetrahydro-1-naphthol product selectivity of 33.1%. Comparative Example 5, the catalyst B-5, has a conversion of only 59.3%. Therefore, the catalyst prepared in this invention has higher activity, selectivity, and stability in the selective hydrogenation of 1-naphthol to 1,2,3,4-tetrahydro-1-naphthol.

[0054] In summary, the evaluation data from Application Examples 1 and 2 demonstrate that the catalyst of this invention, through in-situ immobilization of alkali metal cations (basic centers) with aluminate, synergistically interacts with the active metal, regulating the adsorption configuration of reactant molecules on the catalyst surface and simultaneously enhancing the tautomer structure interconversion of naphthol. This effectively improves the catalytic performance of the catalyst, exhibiting high reactivity, selectivity, and stability in the selective hydrogenation of 2-naphthol or 1-naphthol to synthesize 1,2,3,4-tetrahydronaphthol. Furthermore, the technology of this invention has the advantages of high safety in use and easy separation and recovery, making it suitable for industrial production.

Claims

1. A catalyst for synthesizing 1,2,3,4-tetrahydronaphthol, characterized in that: The catalyst comprises the following components by weight percentage: 75-90% activated carbon, 5-15% aluminate, and 5-15% active metal; the aluminate is sodium aluminate or potassium aluminate; and the active metal is nickel.

2. The catalyst for synthesizing 1,2,3,4-tetrahydronaphthol according to claim 1, characterized in that: The catalyst has a specific surface area of ​​500-800 m². 2 / g, total pore volume is 0.6-1.0cm³ 3 / g.

3. A method for preparing the catalyst for synthesizing 1,2,3,4-tetrahydronaphthol according to claim 1, characterized in that: Activated carbon was mixed with an active metal salt solution, sodium hydroxide solution was added, and the mixture was impregnated, filtered, washed with water until the pH was neutral, dried and calcined. The calcined solid sample was mixed with aluminum hydroxide and water, and a solid base was added under stirring conditions to react. The mixture was rotary evaporated to obtain a dry solid. The solid was washed with hot ethanol, dried, and then reduced under a hydrogen / argon mixed gas to obtain the catalyst.

4. The preparation method according to claim 3, characterized in that: The active metal salt is one or more of nickel nitrate hexahydrate, nickel chloride hexahydrate, and nickel sulfate hexahydrate.

5. The preparation method according to claim 3, characterized in that: The roasting temperature is 450-650℃.

6. The preparation method according to claim 3, characterized in that: The solid alkali is one or both of sodium hydroxide and potassium hydroxide, and the molar ratio of the solid alkali to aluminum hydroxide is 1.95-2:

1.

7. The preparation method according to claim 3, characterized in that: After adding solid alkali, heat to 80-100℃ for reaction; the mixture is rotary evaporated at 60-70℃.

8. The preparation method according to claim 3, characterized in that: The reduction temperature is 300-450℃, and the hydrogen volume concentration in the hydrogen / argon mixture is 5%.

9. The application of the catalyst for synthesizing 1,2,3,4-tetrahydronaphthol according to claim 1, characterized in that: Application of the catalyst in the selective hydrogenation synthesis of 1,2,3,4-tetrahydronaphthol.

10. The application according to claim 9, characterized in that: The catalyst is supported by alkali metal cations in situ, which synergistically interact with the active metal to regulate the adsorption configuration of reactant molecules on the catalyst surface, promote the interconversion of naphthol alcohol ketone structure, and thus improve the selectivity for synthesizing 1,2,3,4-tetrahydronaphthol.

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