A method for preparing a highly efficient hydrogenation catalyst and its application in the synthesis of γ-butyrolactone

Abstract

This invention discloses a method for preparing a highly efficient hydrogenation catalyst, comprising the following steps: preparing silicates using tetrapropylammonium hydroxide as a template agent and tetraethyl orthosilicate as a silicon source, followed by alkali treatment to obtain hollow silicate materials; treating the hollow silicate support with 3-aminopropyltriethoxysilane to obtain functionalized hollow silicate materials; loading cerium onto the functionalized hollow silicate material as a support, then adding it to a mixed metal salt solution of nickel nitrate hexahydrate and titanium sulfate for co-precipitation treatment to obtain a catalyst precursor; mixing ethanol and tetrahydronaphthalene, then adding sodium borohydride and stirring until dissolved to obtain a mixed solvent, adding the catalyst precursor, and transferring the mixture to a high-pressure reactor for sealing treatment to obtain the catalyst. This invention uses self-made hollow silicate materials as a support, sequentially loading cerium, nickel, and titanium, resulting in a catalyst with a large specific surface area and high catalytic activity, effectively improving the purity and yield of γ-butyrolactone in its synthesis.

Description

Technical Field

[0001] This invention relates to the field of γ-butyrolactone synthesis technology, specifically to a method for preparing a highly efficient hydrogenation catalyst and its application in the synthesis of γ-butyrolactone. Background Technology

[0002] γ-Butyrolactone (GBL) is an important chemical intermediate and solvent, widely used in pharmaceuticals, pesticides, electronic chemicals, polymers, and other fields. The catalytic hydrogenation of maleic anhydride is the main route for the industrial production of GBL. This process typically involves the hydrogenation of maleic anhydride to produce succinic anhydride or its ester, followed by further hydrogenation and intramolecular esterification / dehydration ring closure to generate GBL.

[0003] Supported metal catalysts, especially nickel-based catalysts, have been widely studied and applied in the hydrogenation of maleic anhydride to GBL process due to their relatively low cost and good hydrogenation activity. However, existing nickel-based catalysts still have many problems. For example: 1. Insufficient activity and selectivity: While single-nickel catalysts can achieve deep hydrogenation of maleic anhydride to GBL, they often cannot avoid over-hydrogenation, generating byproducts or ring-opening products, leading to reduced GBL selectivity. 2. Low metal dispersion: The dispersion of nickel metal particles on the support surface directly affects catalytic activity and metal utilization. Nickel particles supported by traditional impregnation methods are prone to migration and sintering agglomeration during preparation or reaction, resulting in a reduction of active sites and rapid catalyst deactivation. Sintering problems are particularly prominent under high-temperature and high-pressure hydrogenation reaction conditions. 3. Support performance limitations: The specific surface area, pore structure, or surface properties of commonly used supports (such as Al2O3, SiO2) are insufficient to achieve high dispersion and stable anchoring of the metal component. 4. Poor catalyst stability: Existing catalysts may suffer from carbon deposition or poisoning during the reaction, resulting in limited catalyst lifespan and the need for frequent regeneration or replacement, increasing production costs.

[0004] To address the aforementioned issues, it is necessary to provide a catalyst with high catalytic activity and good stability for the synthesis of γ-butyrolactone. Summary of the Invention

[0005] The technical problem to be solved by this invention is to provide a method for preparing a high-efficiency hydrogenation catalyst and its application in the synthesis of γ-butyrolactone, addressing the shortcomings of existing technologies. This invention uses a self-made hollow silicate material as a support, and sequentially loads cerium, nickel and titanium as catalytic active components. The resulting catalyst has a large specific surface area and high catalytic activity, which effectively improves the purity and yield of γ-butyrolactone in its synthesis.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0007] A method for preparing a highly efficient hydrogenation catalyst includes the following steps:

[0008] (1) Using tetrapropylammonium hydroxide as a template agent and tetraethyl orthosilicate as a silicon source, silicates are prepared by hydrothermal reaction and then treated with alkali to obtain hollow silicate materials;

[0009] (2) The above hollow silicate support was treated with 3-aminopropyltriethoxysilane to obtain functionalized hollow silicate material;

[0010] (3) Using the above-mentioned functionalized hollow silicate material as a carrier, cerium is loaded by in-situ impregnation reduction method, and then added to a mixed metal salt solution of nickel nitrate hexahydrate and titanium sulfate for co-precipitation treatment to obtain catalyst precursor;

[0011] (4) Mix ethanol and tetrahydronaphthalene, add sodium borohydride and stir until dissolved to obtain a mixed solvent. Add catalyst precursor, transfer the resulting mixture to an autoclave and seal it. Then raise the temperature of the autoclave to 180°C and the pressure to 5 MPa for pretreatment. Then raise the temperature to 268°C at a rate of 2°C / min and raise the pressure to 9 MPa for further treatment. After the reaction is completed, cool to room temperature, filter the reaction solution, wash the precipitate and dry it to obtain the catalyst.

[0012] Preferably, in step (1), the preparation process of the hollow silicate carrier is as follows: tetrapropylammonium hydroxide solution is added to tetraethyl orthosilicate, stirred at room temperature to obtain a gel, the gel is placed in an autoclave and heated to carry out a hydrothermal reaction, then centrifuged, the centrifuged precipitate is calcined once and then treated with alkali, and finally calcined a second time to obtain the hollow silicate carrier.

[0013] Preferably, in step (1), the concentration of the tetrapropylammonium hydroxide solution is 7.8-8.0 wt%, the mass ratio of tetrapropylammonium hydroxide to tetraethyl orthosilicate is (0.2-0.4):1, and the stirring time at room temperature is 3-4 h.

[0014] Preferably, in step (1), the hydrothermal reaction temperature is 170℃ and the time is 40-50h; the calcination temperature is 520-570℃ and the time is 5-6h.

[0015] Preferably, in step (1), during the alkali treatment, tetrapropylammonium hydroxide solution is used as the solvent, with a concentration of 30-35 wt%. During the treatment, the ratio of the amount of calcined powder to the amount of tetrapropylammonium hydroxide solution after the first calcination is 1 g:(7-10 ml). The alkali treatment temperature is 170°C, and the time is 20-30 h. The second calcination temperature is 520-570°C, and the time is 5-6 h.

[0016] Preferably, in step (2), the mass ratio of 3-aminopropyltriethoxysilane to hollow silicate support is (0.01-0.05):1; the treatment temperature is 80℃ and the treatment time is 5-6h.

[0017] Preferably, in step (3), the reducing agent during the in-situ impregnation reduction treatment is ascorbic acid, the cerium source is cerium nitrate hexahydrate, and the mass ratio of cerium nitrate hexahydrate, ascorbic acid, and functionalized hollow silicate material is (0.04-0.05):(0.004-0.005):1; the temperature during the in-situ impregnation reduction treatment is 55-60℃, and the time is 1-2h.

[0018] Preferably, in step (3), the concentrations of nickel nitrate hexahydrate and titanium sulfate in the mixed metal salt solution are 0.1-0.15 mol / ml and 0.09-0.12 mol / ml, respectively; the ratio of the amount of cerium-loaded hollow silicate material to the mixed metal salt solution is 1 g:(40-50) ml; the sodium carbonate solution also includes sodium hydroxide, and the concentrations of sodium carbonate and sodium hydroxide in the sodium carbonate solution are 0.12-0.13 g / ml and 0.1-0.11 g / ml, respectively; during the coprecipitation treatment, sodium carbonate solution is added to adjust the pH of the system to 10, the temperature of the coprecipitation treatment is 40℃, and the time is 10-15 h. Preferably, in step (4), the volume ratio of ethanol to tetrahydronaphthalene is 4:1, the concentration of sodium borohydride added to the mixed solvent is 0.3-0.4wt%, the ratio of catalyst precursor material to mixed solvent is 1g:100ml, the pretreatment time is 20-30min, and the retreatment time is 20-30min.

[0019] This invention also discloses the application of this highly efficient hydrogenation catalyst in the synthesis of γ-butyrolactone, comprising the following steps:

[0020] S1. The high-efficiency hydrogenation catalyst is impregnated with 5wt% H2SO4 for 1-2 hours to obtain the acidification catalyst;

[0021] S2. The high-efficiency hydrogenation catalyst and the acidification catalyst are respectively loaded into the primary fixed-bed reactor and the secondary fixed-bed reactor, and the loading volume of the high-efficiency hydrogenation catalyst and the acidification catalyst is controlled to be 5 ml and 5 ml respectively.

[0022] S3. Hydrogen gas is introduced into the primary fixed-bed reactor and the secondary fixed-bed reactor respectively, and the hydrogen flow rate is controlled at 50 ml / min. The catalyst in the primary fixed-bed reactor is activated at 200℃ for 2 h, and the catalyst in the secondary fixed-bed reactor is activated at 150℃ for 2 h.

[0023] S4. Mix maleic anhydride and anhydrous ethanol to obtain a maleic anhydride solution with a concentration of 18-22 wt%.

[0024] S5. The above maleic anhydride solution is pumped into a primary fixed-bed reactor for a single hydrogenation reaction. The temperature of the single hydrogenation reaction is controlled at 140°C, the reaction pressure at 3.0 MPa, and the mass hourly space velocity (WHSV) of the maleic anhydride solution at 1.0 h⁻¹. -1 The hydrogen-to-oil ratio was 200:1. The feed solution after the primary fixed-bed reactor reaction was pumped into the secondary fixed-bed reactor for a secondary hydrogenation reaction. The temperature of the secondary hydrogenation reaction was controlled at 200℃, the reaction pressure at 5.0 MPa, and the mass hourly space velocity (WHSV) of the feed solution after the reaction was 0.5 h⁻¹. -1 The hydrogen-to-oil ratio is 250:1;

[0025] After the reaction liquid in the S6 two-stage fixed-bed reactor is cooled to room temperature, it is first subjected to vacuum distillation at 50℃ and 10kPa to remove ethanol, and then the target product is recovered by vacuum distillation at 80℃ and 5kPa.

[0026] Due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0027] This invention provides a method for preparing a highly efficient hydrogenation catalyst. The method first prepares a hollow silicate material through a hydrothermal reaction and alkali treatment. This hollow silicate material has a large specific surface area and abundant pores, greatly increasing the loading of active sites. The hollow silicate material is prepared by two calcinations, resulting in a stable porous structure with high mechanical strength, which facilitates the diffusion of reactant and product molecules, reduces internal diffusion resistance, and improves reaction efficiency.

[0028] The hollow silicate material of this invention is functionalized before loading the metal active component, thereby introducing amino active functional groups on the surface of the support. The amino group, as a strong coordination site, can effectively anchor the subsequently loaded cerium ions, preventing their migration and aggregation. Then, through subsequent in-situ reduction, high dispersion and stable loading of metallic cerium are achieved. Moreover, the loading of metallic cerium can promote the dispersion of subsequent metal components nickel and titanium, and can also adjust the electronic properties of nickel, enhance the oxygen storage and release capacity of the catalyst, and significantly improve catalytic activity and stability.

[0029] This invention, after loading cerium onto hollow silicate material, further loads nickel and titanium through co-precipitation and reduction treatment. Nickel, as the main active metal component for hydrogenation, forms a tight interface with titanium and cerium. Titanium and cerium may modulate the electronic state of nickel and enhance the structural stability of the support, further improving catalytic performance. In the reduction process, sodium borohydride is used as a reducing agent. First, the metal is initially reduced and activated under relatively mild conditions to remove some impurities or weakly bound substances. Then, under high temperature and high pressure conditions, deep reduction and structural reconstruction are carried out to promote the stable loading of the active metal components on the support surface. The resulting highly efficient hydrogenation catalyst exhibits good stability, a large specific surface area, and high catalytic activity.

[0030] The highly efficient hydrogenation catalyst prepared by this invention uses maleic anhydride as a raw material in the catalytic preparation of γ-butyrolactone. The catalyst undergoes sequential hydrogenation catalytic treatment in a primary fixed-bed reactor and a secondary fixed-bed reactor to prepare the target product. In the secondary fixed-bed reactor, the catalyst is acidified to introduce acidic sites, thereby better promoting the cyclization reaction of the primary reaction product and improving the purity and yield of the target product. Prior to the reaction, the catalyst is also activated to further improve its activity. Detailed Implementation

[0031] To better understand the above-mentioned objectives, features, and advantages of the present invention, the solutions of the present invention will be further described below. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other.

[0032] Many specific details are set forth in the following description in order to provide a full understanding of the invention, but the invention may also be practiced in other ways different from those described herein; obviously, the embodiments in the specification are only some embodiments of the invention, and not all embodiments.

[0033] To further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the scope of the claims of the present invention.

[0034] Example 1

[0035] A method for preparing a highly efficient hydrogenation catalyst includes the following steps:

[0036] (1) Mix a 40wt% tetrapropylammonium hydroxide solution with 30ml of deionized water and stir for 20min. Control the concentration of the mixed solution to be 7.8wt%. Add tetraethyl orthosilicate. The mass ratio of tetrapropylammonium hydroxide to tetraethyl orthosilicate is 0.2:1. Stir at room temperature for 3h. Transfer the resulting sol to a hydrothermal reactor and seal it. React at 170℃ for 40h. After the reaction is completed, cool to room temperature. Filter the reaction solution. After the precipitate is dried, place it in a muffle furnace and dry at 550℃ for 5h to obtain silicate material.

[0037] (2) The above silicate material was mixed with 30 ml of 30 wt% tetrapropylammonium hydroxide aqueous solution. The ratio of silicate material to tetrapropylammonium hydroxide aqueous solution was controlled to be 1 g: 10 ml. The mixture was sonicated at 300 W for 20 min. The resulting solution was reacted at 170 °C for 20 h. After the reaction was completed, the mixture was cooled to room temperature, the reaction solution was filtered, and the resulting precipitate was dried and placed in a muffle furnace. It was dried at 550 °C for 5 h to obtain hollow silicate carrier material.

[0038] (3) Mix 0.02 g of 3-aminopropyltriethoxysilane with 100 ml of ethanol solution (the volume ratio of ethanol to deionized water is 9:1), add the above hollow silicate material (the mass ratio of 3-aminopropyltriethoxysilane to hollow silicate material is 0.01:1), treat at 80 °C for 5 h, cool to room temperature after treatment, filter the reaction solution, dry the precipitate, and obtain the functionalized hollow silicate material;

[0039] (4) Dissolve 1g of cerium nitrate hexahydrate and ascorbic acid in 50ml of deionized water to obtain a reduction system solution. Add functionalized hollow silicate material (the mass ratio of cerium nitrate hexahydrate, ascorbic acid, and functionalized hollow silicate material is 0.04:0.004:1). Reduce the solution at 55℃ for 1h. After the treatment, cool to room temperature, filter, and dry the precipitate to obtain cerium-loaded hollow silicate material.

[0040] (5) Dissolve nickel nitrate hexahydrate and titanium sulfate in 40 ml of deionized water to obtain a mixed metal salt solution (the concentrations of nickel nitrate hexahydrate and titanium sulfate are 0.1 mol / ml and 0.09 mol / ml, respectively); add cerium-loaded hollow silicate material to the mixed metal salt solution (the ratio of cerium-loaded hollow silicate material to mixed metal salt solution is 1 g: 40 ml), stir at room temperature for 30 min, then add sodium carbonate solution (the concentrations of sodium carbonate and sodium hydroxide in the solution are 0.12 g / ml and 0.1 g / ml, respectively) to adjust the pH of the system to 10, treat at 40 °C for 10 h, filter after precipitation, and dry the precipitate to obtain the catalyst precursor;

[0041] (6) Mix 40 ml of ethanol and 10 ml of tetrahydronaphthalene, then add sodium borohydride and stir until dissolved to obtain a mixed solvent. The concentration of sodium borohydride in the mixed solvent is 0.3 wt%. Add the above catalyst precursor (the ratio of catalyst precursor material to mixed solvent is 1 g: 100 ml). Transfer the resulting mixture to a high-pressure reactor and seal it. Then raise the temperature of the high-pressure reactor to 180 °C and the pressure to 5 MPa for 20 min of pretreatment. Then raise the temperature to 268 °C at a rate of 2 °C / min and raise the pressure to 9 MPa for another 20 min. After the reaction is completed, cool to room temperature, filter the reaction solution, wash the precipitate and dry it to obtain a high-efficiency hydrogenation catalyst.

[0042] Example 2

[0043] A method for preparing a highly efficient hydrogenation catalyst includes the following steps:

[0044] (1) Mix a 40wt% tetrapropylammonium hydroxide solution with 30ml of deionized water and stir for 25min. Control the concentration of the mixed solution to be 7.9wt%. Add tetraethyl orthosilicate. The mass ratio of tetrapropylammonium hydroxide to tetraethyl orthosilicate is 0.3:1. Stir at room temperature for 3.5h. Transfer the resulting sol to a hydrothermal reactor and seal it. React at 170℃ for 45h. After the reaction is completed, cool to room temperature. Filter the reaction solution. After the precipitate is dried, place it in a muffle furnace and dry at 550℃ for 5.5h to obtain silicate material.

[0045] (2) The above silicate material was mixed with 30 ml of 30 wt% tetrapropylammonium hydroxide aqueous solution. The ratio of silicate material to tetrapropylammonium hydroxide aqueous solution was controlled to be 1 g: 10 ml. The mixture was sonicated at 300 W for 20 min. The resulting solution was reacted at 170 °C for 24 h. After the reaction was completed, the mixture was cooled to room temperature, the reaction solution was filtered, and the resulting precipitate was dried and placed in a muffle furnace. It was dried at 550 °C for 5.5 h to obtain hollow silicate carrier material.

[0046] (3) Mix 0.05 g of 3-aminopropyltriethoxysilane with 100 ml of ethanol solution (the volume ratio of ethanol to deionized water is 9:1), add the above hollow silicate material (the mass ratio of 3-aminopropyltriethoxysilane to hollow silicate material is 0.02:1), treat at 80 °C for 5.5 h, cool to room temperature after treatment, filter the reaction solution, dry the precipitate, and obtain the functionalized hollow silicate material;

[0047] (4) Dissolve 1g of cerium nitrate hexahydrate and ascorbic acid in 50ml of deionized water to obtain a reduction system solution. Add functionalized hollow silicate material (the mass ratio of cerium nitrate hexahydrate, ascorbic acid, and functionalized hollow silicate material is 0.045:0.0045:1). Reduce the solution at 58℃ for 1.5h. After the treatment, cool to room temperature, filter, and dry the precipitate to obtain cerium-loaded hollow silicate material.

[0048] (5) Dissolve nickel nitrate hexahydrate and titanium sulfate in 45 ml of deionized water to obtain a mixed metal salt solution (the concentrations of nickel nitrate hexahydrate and titanium sulfate are 0.12 mol / ml and 0.10 mol / ml, respectively); add cerium-loaded hollow silicate material to the mixed metal salt solution (the ratio of cerium-loaded hollow silicate material to mixed metal salt solution is 1 g: 45 ml), stir at room temperature for 30 min, then add sodium carbonate solution (the concentrations of sodium carbonate and sodium hydroxide in the solution are 0.125 g / ml and 0.1 g / ml, respectively) to adjust the pH of the system to 10, treat at 40 °C for 12 h, filter after precipitation, and dry the precipitate to obtain the catalyst precursor;

[0049] (6) Mix 40 ml of ethanol and 10 ml of tetrahydronaphthalene, then add sodium borohydride and stir until dissolved to obtain a mixed solvent. The concentration of sodium borohydride in the mixed solvent is 0.35 wt%. Add the above catalyst precursor (the ratio of catalyst precursor material to mixed solvent is 1 g: 100 ml). Transfer the resulting mixture to a high-pressure reactor and seal it. Then raise the temperature of the high-pressure reactor to 180 °C and the pressure to 5 MPa for pretreatment for 25 min. Then raise the temperature to 268 °C at a rate of 2 °C / min and raise the pressure to 9 MPa for another 25 min. After the reaction is completed, cool to room temperature, filter the reaction solution, wash the precipitate and dry it to obtain a high-efficiency hydrogenation catalyst.

[0050] Example 3

[0051] A method for preparing a highly efficient hydrogenation catalyst includes the following steps:

[0052] (1) Mix a 40wt% tetrapropylammonium hydroxide solution with 30ml of deionized water and stir for 30min. Control the concentration of the mixed solution to be 8.0wt%. Add tetraethyl orthosilicate. The mass ratio of tetrapropylammonium hydroxide to tetraethyl orthosilicate is 0.4:1. Stir at room temperature for 4h. Transfer the resulting sol to a hydrothermal reactor and seal it. React at 170℃ for 50h. After the reaction is completed, cool to room temperature. Filter the reaction solution. After the precipitate is dried, place it in a muffle furnace and dry at 550℃ for 6h to obtain silicate material.

[0053] (2) The above silicate material was mixed with 30 ml of 35 wt% tetrapropylammonium hydroxide aqueous solution. The ratio of silicate material to tetrapropylammonium hydroxide aqueous solution was controlled to be 1 g: 10 ml. The mixture was sonicated at 300 W for 20 min. The resulting solution was reacted at 170 °C for 30 h. After the reaction was completed, the mixture was cooled to room temperature, the reaction solution was filtered, and the resulting precipitate was dried and placed in a muffle furnace. It was dried at 550 °C for 6 h to obtain hollow silicate carrier material.

[0054] (3) Mix 0.1 g of 3-aminopropyltriethoxysilane with 100 ml of ethanol solution (the volume ratio of ethanol to deionized water is 9:1), add the above hollow silicate material (the mass ratio of 3-aminopropyltriethoxysilane to hollow silicate material is 0.05:1), treat at 80 °C for 6 h, cool to room temperature after treatment, filter the reaction solution, dry the precipitate, and obtain the functionalized hollow silicate material;

[0055] (4) Dissolve 1g of cerium nitrate hexahydrate and ascorbic acid in 50ml of deionized water to obtain a reduction system solution. Add functionalized hollow silicate material (the mass ratio of cerium nitrate hexahydrate, ascorbic acid, and functionalized hollow silicate material is 0.05:0.005:1). Reduce the solution at 60℃ for 2h. After the treatment, cool to room temperature, filter, and dry the precipitate to obtain cerium-loaded hollow silicate material.

[0056] (5) Dissolve nickel nitrate hexahydrate and titanium sulfate in 50 ml of deionized water to obtain a mixed metal salt solution (the concentrations of nickel nitrate hexahydrate and titanium sulfate are 0.15 mol / ml and 0.12 mol / ml, respectively); add cerium-loaded hollow silicate material to the mixed metal salt solution (the ratio of cerium-loaded hollow silicate material to mixed metal salt solution is 1 g: 50 ml), stir at room temperature for 30 min, then add sodium carbonate solution (the concentrations of sodium carbonate and sodium hydroxide in the solution are 0.13 g / ml and 0.11 g / ml, respectively) to adjust the pH of the system to 10, treat at 40 °C for 15 h, filter after precipitation, and dry the precipitate to obtain the catalyst precursor;

[0057] (6) Mix 40 ml of ethanol and 10 ml of tetrahydronaphthalene, then add sodium borohydride and stir until dissolved to obtain a mixed solvent. The concentration of sodium borohydride in the mixed solvent is 0.4 wt%. Add the above catalyst precursor (the ratio of catalyst precursor material to mixed solvent is 1 g: 100 ml). Transfer the resulting mixture to a high-pressure reactor and seal it. Then raise the temperature of the high-pressure reactor to 180 °C and the pressure to 5 MPa for 30 min of pretreatment. Then raise the temperature to 268 °C at a rate of 2 °C / min and raise the pressure to 9 MPa for another 30 min. After the reaction is completed, cool to room temperature, filter the reaction solution, wash the precipitate and dry it to obtain a high-efficiency hydrogenation catalyst.

[0058] Comparative Example 1

[0059] The difference between this comparative example and Example 3 is that step (3) is not included, while the other operations are the same as in Example 3.

[0060] Comparative Example 2

[0061] The difference between this comparative example and Example 3 is that step (4) is not included, while the other operations are the same as in Example 3.

[0062] Comparative Example 3

[0063] The difference between this comparative example and Example 3 is that step (6) is as follows: 40 ml of ethanol and 10 ml of tetrahydronaphthalene are mixed and sodium borohydride is added and stirred until dissolved to obtain a mixed solvent. The concentration of sodium borohydride in the mixed solvent is 0.4 wt%. The above catalyst precursor is added (the ratio of catalyst precursor material to mixed solvent is 1 g: 100 ml). The resulting mixture is transferred to a high-pressure reactor and sealed. Then the temperature of the high-pressure reactor is raised to 268°C and the pressure is raised to 9 MPa for 60 min. After the reaction is completed, it is cooled to room temperature. The reaction solution is filtered, the precipitate is washed and dried to obtain a high-efficiency hydrogenation catalyst.

[0064] The performance parameters of the high-efficiency hydrogenation catalysts prepared in the above embodiments and comparative examples are shown in Table 1.

[0065] Table 1

[0066]

[0067] As can be seen from the test results in Table 1, the high-efficiency hydrogenation catalyst prepared in the embodiments of the present invention has a large specific surface area and an excellent porous structure.

[0068] In Comparative Example 1, the hollow silicate material was not functionalized, resulting in the absence of amino or other active groups on the support surface. This prevented proper anchoring of the metal, leading to uneven loading of the subsequent metal active components. Metal particles aggregated and blocked some pores, resulting in a decrease in the specific surface area, pore volume, and overall efficiency of the prepared hydrogenation catalyst. Simultaneously, the average pore size increased due to the blockage of small pores. In Comparative Example 2, no cerium was loaded, and the support pores were not filled with Ce, resulting in more pores in the efficient hydrogenation catalyst. The specific surface area and pore volume of the efficient hydrogenation catalyst were higher than in Example 3. In Comparative Example 3, direct high-temperature and high-pressure treatment led to an excessively rapid reduction process of nickel and titanium ions, causing sintering and aggregation of metal particles, resulting in blockage of some pores. Consequently, the specific surface area and pore volume of the prepared efficient hydrogenation catalyst decreased significantly.

[0069] Application Example 1

[0070] The application of highly efficient hydrogenation catalysts in the synthesis of γ-butyrolactone includes the following steps:

[0071] S1. Mix 10g of the high-efficiency hydrogenation catalyst from Example 1 with 1000ml of 5wt% H2SO4, impregnate at room temperature for 1-2h, filter after impregnation, and dry the precipitate to obtain the acidified catalyst.

[0072] S2. The high-efficiency hydrogenation catalyst of Example 1 and the above-mentioned acidification catalyst are respectively loaded into a primary fixed-bed reactor and a secondary fixed-bed reactor, and the loading volume of the high-efficiency hydrogenation catalyst and the acidification catalyst is controlled to be 5 ml and 5 ml respectively.

[0073] S3. Hydrogen gas is introduced into the primary fixed-bed reactor and the secondary fixed-bed reactor respectively, and the hydrogen flow rate is controlled at 50 ml / min. The catalyst in the primary fixed-bed reactor is activated at 200℃ for 2 h, and the catalyst in the secondary fixed-bed reactor is activated at 150℃ for 2 h.

[0074] S4. Mix 200g maleic anhydride and 800ml anhydrous ethanol to obtain a maleic anhydride solution with a concentration of 18-22wt%.

[0075] S5. The above maleic anhydride solution is pumped into a primary fixed-bed reactor for a single hydrogenation reaction. The temperature of the single hydrogenation reaction is controlled at 140°C, the reaction pressure at 3.0 MPa, and the mass hourly space velocity (WHSV) of the maleic anhydride solution at 1.0 h⁻¹. -1 The hydrogen-to-oil ratio was 200:1. The feed solution after the primary fixed-bed reactor reaction was pumped into the secondary fixed-bed reactor for a secondary hydrogenation reaction. The temperature of the secondary hydrogenation reaction was controlled at 200℃, the reaction pressure at 5.0 MPa, and the mass hourly space velocity (WHSV) of the feed solution after the reaction was 0.5 h⁻¹. -1 The hydrogen-to-oil ratio is 250:1;

[0076] After the reaction liquid in the S6 two-stage fixed-bed reactor is cooled to room temperature, it is first subjected to vacuum distillation at 50℃ and 10kPa to remove ethanol, and then the target product is recovered by vacuum distillation at 80℃ and 5kPa.

[0077] Application Example 2

[0078] The difference from Application Example 1 is that an equal amount of the high-efficiency hydrogenation catalyst of Example 2 is used instead of the high-efficiency hydrogenation catalyst of Example 1, while other operations are the same as in Application Example 1.

[0079] Application Example 3

[0080] The difference from Application Example 1 is that an equal amount of the high-efficiency hydrogenation catalyst of Example 3 is used instead of the high-efficiency hydrogenation catalyst of Example 1, while other operations are the same as in Application Example 1.

[0081] Application Comparative Example 1

[0082] The difference from Application Example 1 is that an equal amount of the high-efficiency hydrogenation catalyst of Comparative Example 1 is used instead of the high-efficiency hydrogenation catalyst of Example 1, while other operations are the same as in Application Example 1.

[0083] Application Comparative Example 2

[0084] The difference from Application Example 1 is that an equal amount of the high-efficiency hydrogenation catalyst of Comparative Example 2 is used instead of the high-efficiency hydrogenation catalyst of Example 1; all other operations are the same as in Application Example 1. Application Comparative Example 3

[0085] The difference from Application Example 1 is that an equal amount of the high-efficiency hydrogenation catalyst of Comparative Example 3 is used instead of the high-efficiency hydrogenation catalyst of Example 1, while other operations are the same as in Application Example 1.

[0086] Application Comparative Example 4

[0087] The difference from Application Example 1 is that step S1 is not included. In step S2, an equal amount of the high-efficiency hydrogenation catalyst of Example 1 is used to replace the acidification catalyst. Other operations are the same as in Application Example 1.

[0088] Application Comparative Example 5

[0089] The difference from Application Example 1 is that step S3 is not included, but the other operations are the same as in Application Example 1.

[0090] As tested in the above application examples, the purity and single-batch yield of the target product γ-butyrolactone after 1000 hours of continuous hydrogenation process experiment are shown in Table 2.

[0091] Single-batch yield (%) = [(actual yield of γ-butyrolactone per batch × purity of γ-butyrolactone) / (theoretical yield of γ-butyrolactone per batch)] × 100%.

[0092] Table 2

[0093] γ-Butyrolactone purity, % γ-Butyrolactone yield, % Application Example 1 99.7 97.7 Application Example 2 99.8 97.8 Application Example 3 99.8 97.9 Application Comparative Example 1 94.5 92.3 Application Comparative Example 2 96.1 94.5 Application Comparative Example 3 95.2 92.9 Application Comparative Example 4 95.1 93.2 Application Comparative Example 5 95.5 93.7

[0094] As can be seen from the test results in Table 2, the high-efficiency hydrogenation catalyst prepared in the embodiments of the present invention has a large specific surface area, good dispersion of the supported metal active components, and high catalytic activity. The purity of the target product γ-butyrolactone obtained is over 99%, and the product yield is over 97%. In contrast, the catalysts of Comparative Examples 1-3 have reduced specific surface area and lower dispersion of the metal active components, resulting in a significant decrease in the purity and yield of the target product γ-butyrolactone obtained by their catalysis. In Comparative Example 4, the high-efficiency hydrogenation catalyst was not acidified, resulting in fewer acidic sites on the catalyst, which could not effectively promote the cyclization reaction in the secondary hydrogenation, leading to a decrease in the purity and yield of the target product. In Comparative Example 5, the catalyst was not activated, resulting in insufficient catalyst activity and stability, especially reducing the purity and yield of the target product obtained by catalysis.

[0095] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of these embodiments are merely to aid in understanding the method and core ideas of the present invention, including the best mode, and to enable any person skilled in the art to practice the present invention, including manufacturing and using any device or system, and implementing any combined method. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims. The scope of protection of this patent is defined by the claims and may include other embodiments that can be conceived by those skilled in the art. If these other embodiments have structural elements similar to those expressed in the claims, or if they include equivalent structural elements that are not substantially different from those expressed in the claims, then these other embodiments should also be included within the scope of the claims.

Claims

1. A process for the preparation of a high-efficiency hydrogenation catalyst, characterized in that, The method comprises the following steps: (1) using tetrapropyl ammonium hydroxide as a template agent and tetraethyl orthosilicate as a silicon source, a silicate is prepared by a hydrothermal reaction, and then the silicate is treated by an alkali to obtain a hollow silicate material; the precipitate after the hydrothermal reaction is dried and then calcined once, and then treated by an alkali, and finally calcined twice; the temperature of the first calcination is 520-570 DEG C, and the time is 5-6h; during the alkali treatment, tetrapropyl ammonium hydroxide solution is used as a solvent, the concentration of the tetrapropyl ammonium hydroxide solution is 30-35wt%, and the use amount ratio of the calcined powder to the tetrapropyl ammonium hydroxide solution is 1g:(7-10ml) during the alkali treatment; the temperature of the alkali treatment is 170 DEG C, and the time is 20-30h; the temperature of the second calcination is 520-570 DEG C, and the time is 5-6h; (2) the hollow silicate carrier is treated by 3-aminopropyl triethoxysilane to obtain a functionalized hollow silicate material; (3) the functionalized hollow silicate material is used as a carrier to load cerium by an in-situ impregnation reduction method, and then added into a mixed metal salt solution of nickel nitrate hexahydrate and titanium sulfate to perform a co-precipitation treatment, thereby obtaining a catalyst precursor; (4) a mixed solvent is obtained by mixing ethanol and tetrahydro naphthalene, adding sodium borohydride and stirring until the sodium borohydride is dissolved, adding the catalyst precursor, and then transferring the obtained mixed solution into a high-pressure kettle to seal the high-pressure kettle; the high-pressure kettle is subjected to a first temperature and pressure rising for pretreatment, and then subjected to a second temperature and pressure rising for secondary treatment; after the reaction is completed, the reaction liquid is filtered, the precipitate is washed and dried, and a high-efficiency hydrogenation catalyst is obtained; The pretreatment is to raise the temperature of the high-pressure kettle to 180 DEG C and the pressure to 5MPa for pretreatment for 20-30min, and the secondary treatment is to raise the temperature to 268 DEG C at a rate of 2 DEG C / min and the pressure to 9MPa for secondary treatment for 20-30min.

2. The method for preparing a high-efficiency hydrogenation catalyst according to claim 1, characterized in that, In step (1), the mass ratio of tetrapropyl ammonium hydroxide to tetraethyl orthosilicate is (0.2-0.4):1; before the hydrothermal reaction, the tetraethyl orthosilicate and tetrapropyl ammonium hydroxide solution with a concentration of 7.8-8.0wt% are mixed and stirred at room temperature for 3-4h; the temperature of the hydrothermal reaction is 170 DEG C, and the time is 40-50h.

3. The method for preparing a high-efficiency hydrogenation catalyst according to claim 1, characterized in that, In step (2), the mass ratio of 3-aminopropyl triethoxysilane to the hollow silicate carrier is (0.01-0.05):1; the temperature during the treatment is 80 DEG C, and the time is 5-6h.

4. The method for preparing a high-efficiency hydrogenation catalyst according to claim 1, characterized in that, In step (3), the cerium source during the in-situ impregnation reduction treatment is cerium nitrate hexahydrate, and the reducing agent is ascorbic acid; the mass ratio of cerium nitrate hexahydrate, ascorbic acid and the functionalized hollow silicate material is (0.04-0.05):(0.004-0.005):1; the temperature during the in-situ impregnation reduction treatment is 55-60 DEG C, and the time is 1-2h.

5. The method for preparing a high-efficiency hydrogenation catalyst according to claim 1, characterized in that, In step (3), in the mixed metal salt solution, the concentrations of nickel nitrate hexahydrate and titanium sulfate are 0.1-0.15mol / ml and 0.09-0.12mol / ml respectively; the use amount ratio of the cerium-loaded hollow silicate material to the mixed metal salt solution is 1g:(40-50)ml.

6. The process for preparing a high-efficiency hydrogenation catalyst according to claim 1, characterized by, In step (3), the pH of the system is adjusted to 10 by adding sodium carbonate solution during the co-precipitation treatment, the temperature of the co-precipitation treatment is 40°C, and the time is 10-15 h; the sodium carbonate solution also includes sodium hydroxide, and the concentrations of sodium carbonate and sodium hydroxide in the sodium carbonate solution are 0.12-0.13 g / ml and 0.1-0.11 g / ml, respectively.

7. The method for preparing a high-efficiency hydrogenation catalyst according to claim 1, characterized in that, In step (4), the volume ratio of ethanol to tetrahydronaphthalene is 4:1, and the concentration of sodium borohydride in the mixed solvent is 0.3-0.4 wt%; the ratio of the amount of catalyst precursor material to the mixed solvent is 1 g:100 ml.

8. Use of the high-efficiency hydrogenation catalyst prepared according to the method of any one of claims 1 to 7 for synthesis of γ-butyrolactone, characterized in that, The method comprises the following steps: S1, impregnating the high-efficiency hydrogenation catalyst with 5 wt% H2SO4 for 1-2 h to obtain an acidified catalyst; S2, loading the high-efficiency hydrogenation catalyst and the acidified catalyst into a first-stage fixed bed reactor and a second-stage fixed bed reactor, respectively, and controlling the loading volumes of the high-efficiency hydrogenation catalyst and the acidified catalyst to be 5 ml and 5 ml, respectively; S3, introducing hydrogen into the first-stage fixed bed reactor and the second-stage fixed bed reactor, respectively, and controlling the hydrogen flow rate to be 50 ml / min, so that the catalyst in the first-stage fixed bed reactor is activated at 200°C for 2 h, and the catalyst in the second-stage fixed bed reactor is activated at 150°C for 2 h; S4, mixing maleic anhydride and anhydrous ethanol to obtain a maleic anhydride solution with a concentration of 18-22 wt%; S5, the maleic anhydride solution is pumped into a first fixed bed reactor for a first hydrogenation reaction, the temperature of the first hydrogenation reaction is controlled at 140℃, the reaction pressure is 3.0 MPa, the mass space velocity of the maleic anhydride solution is 1.0 h -1 -1, and the hydrogen / oil ratio is 200:1; the liquid after the first fixed bed reactor reaction is pumped into a second fixed bed reactor for a second hydrogenation reaction, the temperature of the second hydrogenation reaction is controlled at 200℃, the reaction pressure is 5.0 MPa, the mass space velocity of the liquid after the reaction is 0.5 h -1 -1, and the hydrogen / oil ratio is 250:1; S6, after the reaction liquid in the second-stage fixed bed reactor is cooled to room temperature, first performing vacuum distillation at 50°C and 10 kPa to remove ethanol, and then performing vacuum distillation at 80°C and 5 kPa to recover the target product.

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