Preparation method of high-efficiency hydrogenation catalyst and application of high-efficiency hydrogenation catalyst in synthesis of gamma-butyrolactone

Abstract

The invention discloses a preparation method of a high-efficiency hydrogenation catalyst, which comprises the following steps: preparing silicate by using tetrapropylammonium hydroxide as a template agent and tetraethoxysilane as a silicon source, and carrying out alkali treatment to obtain a hollow silicate material; 3-aminopropyltriethoxysilane is adopted to treat the hollow silicate carrier, and a functionalized hollow silicate material is obtained; the preparation method comprises the following steps: loading cerium by taking a functionalized hollow silicate material as a carrier, and then adding into a mixed metal salt solution of nickel nitrate hexahydrate and titanium sulfate for coprecipitation treatment to obtain a catalyst precursor; mixing ethanol and tetrahydronaphthalene, adding sodium borohydride, stirring until the sodium borohydride is dissolved to obtain a mixed solvent, adding the catalyst precursor, transferring the mixed solution into a high-pressure kettle, and sealing to obtain the catalyst. The self-made hollow silicate material is adopted as the carrier, cerium, nickel and titanium are loaded in sequence, the prepared catalyst is large in specific surface area and high in catalytic activity, and the purity and yield of gamma-butyrolactone are effectively improved when the catalyst is used in gamma-butyrolactone synthesis.

Description

Technical Field

[0001] The present invention relates to the technical field of synthesis of gamma-butyrolactone, and in particular to a preparation method of a high-efficiency hydrogenation catalyst and application of the catalyst in synthesis of gamma-butyrolactone. Background Art

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

[0003] Supported metal catalysts, particularly nickel-based catalysts, have been widely studied and applied in the hydrogenation of maleic anhydride to GBL due to their relatively low cost and excellent hydrogenation activity. However, existing nickel-based catalysts still suffer from numerous challenges. For example, 1. Inadequate activity and selectivity: While single-component nickel catalysts achieve deep hydrogenation of maleic anhydride to GBL, they often struggle to 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 impacts catalytic activity and metal utilization. Nickel particles supported by traditional impregnation methods are prone to migration and sintering agglomeration during the preparation or reaction process, resulting in a reduction in active sites and rapid catalyst deactivation. This sintering problem is particularly prominent under high-temperature and high-pressure hydrogenation reaction conditions. 3. Support performance limitations: Commonly used supports (such as Al2O3 and SiO2) lack sufficient specific surface area, pore structure, or surface properties to achieve high dispersion and stable anchoring of the metal components. 4. Poor catalyst stability: Existing catalysts can suffer from carbon deposition or poisoning during the reaction, limiting their service life and requiring frequent regeneration or replacement, increasing production costs.

[0004] In view of the above problems, it is necessary to provide a catalyst with high catalytic activity and good stability for use in the synthesis of γ-butyrolactone. Summary of the Invention

[0005] The technical problem to be solved by the present invention is: to address the deficiencies in the prior art, to provide a method for preparing a high-efficiency hydrogenation catalyst and its application in the synthesis of γ-butyrolactone. The present invention adopts a self-made hollow silicate material as a carrier, and sequentially loads metal cerium, nickel and titanium as catalytically active components. The prepared catalyst has a large specific surface area and high catalytic activity, and is used in the synthesis of γ-butyrolactone to effectively improve the purity and yield of γ-butyrolactone.

[0006] In order to solve the above technical problems, the technical solution of the present invention is:

[0007] A method for preparing a high-efficiency hydrogenation catalyst comprises the following steps:

[0008] (1) Using tetrapropylammonium hydroxide as a template and ethyl orthosilicate as a silicon source, a silicate is prepared by a hydrothermal reaction, and then treated with an alkali to obtain a hollow silicate material;

[0009] (2) treating the hollow silicate carrier with 3-aminopropyltriethoxysilane to obtain a functionalized hollow silicate material;

[0010] (3) using the functionalized hollow silicate material as a carrier, loading cerium by an in-situ impregnation reduction method, and then adding it to a mixed metal salt solution of nickel nitrate hexahydrate and titanium sulfate for co-precipitation to obtain a catalyst precursor;

[0011] (4) Ethanol and tetralin are mixed, sodium borohydride is added, and the mixture is stirred until dissolved to obtain a mixed solvent. A catalyst precursor is added, and the obtained mixed solution is transferred to an autoclave and sealed. The temperature of the autoclave is then increased to 180°C and the pressure is increased to 5 MPa for pretreatment. The mixture is then heated to 268°C at a rate of 2°C / min and the pressure is increased to 9 MPa for further treatment. After the reaction is completed, the mixture is cooled to room temperature, the reaction solution is filtered, the precipitate is washed, and then dried to obtain the catalyst.

[0012] Preferably, in step (1), the preparation process of the hollow silicate carrier is specifically as follows: adding ethyl orthosilicate to a tetrapropylammonium hydroxide solution, stirring at room temperature to obtain a gel, placing the gel in an autoclave and heating it for a hydrothermal reaction, then centrifuging it, calcining the centrifugal precipitate once and then treating it with alkali, and finally calcining it twice 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 ethyl orthosilicate is (0.2-0.4):1; and the stirring time at room temperature is 3-4 h.

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

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

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

[0017] Preferably, in step (3), the reducing agent during the in-situ immersion 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 immersion reduction treatment is 55-60°C, 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 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, the sodium carbonate solution is added to adjust the pH of the system to 10, the coprecipitation treatment temperature is 40°C, and the time is 10-15 h. Preferably, in step (4), the volume ratio of ethanol to tetralin is 4:1, the concentration of sodium borohydride added to the mixed solvent is 0.3-0.4wt%; the amount ratio of the catalyst precursor material to the mixed solvent is 1g:100ml; the pretreatment time is 20-30min, and the re-treatment time is 20-30min.

[0019] The present invention also discloses the application of the high-efficiency hydrogenation catalyst in the synthesis of γ-butyrolactone, which comprises the following steps:

[0020] S1. Immerse the high-efficiency hydrogenation catalyst in 5 wt% H2SO4 for 1-2 h to obtain an acidified catalyst;

[0021] S2. Loading a high-efficiency hydrogenation catalyst and an acidification catalyst into the primary fixed-bed reactor and the secondary fixed-bed reactor, respectively, controlling the loading volumes of the high-efficiency hydrogenation catalyst and the acidification catalyst to be 5 ml and 5 ml;

[0022] S3. Hydrogen was introduced into the primary fixed-bed reactor and the secondary fixed-bed reactor respectively, with the hydrogen flow rate controlled at 50 ml / min, and the catalyst in the primary fixed-bed reactor was activated at 200° C. for 2 h, and the catalyst in the secondary fixed-bed reactor was activated at 150° C. for 2 h;

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

[0024] S5. Pump the maleic anhydride solution into a first-stage fixed-bed reactor for a hydrogenation reaction. Control the temperature of the hydrogenation reaction to be 140° C., the reaction pressure to be 3.0 MPa, and the mass space velocity of the maleic anhydride solution to be 1.0 h -1 , the hydrogen-oil ratio is 200:1; the liquid after the reaction in the first fixed bed reactor is pumped into the second fixed bed reactor for secondary hydrogenation reaction. The temperature of the secondary hydrogenation reaction is controlled to be 200 ° C, the reaction pressure is 5.0 MPa, and the mass space velocity of the liquid after the reaction is 0.5h -1 , hydrogen-to-oil ratio is 250:1;

[0025] S6. After the reaction liquid in the secondary fixed-bed reactor is cooled to room temperature, it is first subjected to reduced pressure distillation at 50°C and 10 kPa to remove ethanol, and then to reduced pressure distillation at 80°C and 5 kPa to recover the target product.

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

[0027] The present invention provides a method for preparing a highly efficient hydrogenation catalyst. This 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, significantly increasing the loading capacity of active sites. The hollow silicate material is calcined twice during preparation. The resulting hollow silicate material has a stable porous structure and 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 the present invention is functionalized before loading the metal active components, thereby introducing amino active functional groups on the carrier surface. The amino groups serve as strong coordination sites and can effectively anchor the subsequently loaded cerium ions to prevent their migration and agglomeration. Then, through subsequent in-situ reduction, highly dispersed and stable loading of metallic cerium is achieved. Moreover, the loading of metallic cerium can not only promote the dispersion of the subsequent metal components nickel and titanium, but also regulate the electronic properties of nickel, enhance the oxygen storage and release capacity of the catalyst, and significantly improve the catalytic activity and stability.

[0029] After loading cerium onto the hollow silicate material, the present invention also loads metallic nickel and titanium through coprecipitation and reduction treatment. The metallic nickel, as the main hydrogenation-active metal component, forms a close contact interface with the metallic titanium and metallic cerium. The metallic titanium and metallic cerium may regulate the electronic state of the nickel and enhance the structural stability of the support, further improving the catalytic performance. The present invention uses sodium borohydride as a reducing agent during the reduction process. The metal is then initially reduced and activated under relatively mild conditions to remove some impurities or weakly bound substances. Deep reduction and structural reconstruction are then performed under high temperature and high pressure conditions to promote the stable loading of the metallic active components on the support surface. The resulting high-efficiency hydrogenation catalyst has good stability, a large specific surface area, and high catalytic activity.

[0030] The high-efficiency hydrogenation catalyst prepared by the present invention uses maleic anhydride as the raw material for catalytic production of γ-butyrolactone. The catalyst undergoes hydrogenation catalytic treatment in a primary fixed-bed reactor and then a secondary fixed-bed reactor to produce the target product. The catalyst in the secondary fixed-bed reactor undergoes an acidification treatment to introduce acidic sites, thereby promoting the cyclization reaction of the primary reaction product and increasing the purity and yield of the target product. Prior to the reaction, the catalyst is activated to improve its activity. DETAILED DESCRIPTION

[0031] In order to more clearly understand the above-mentioned objectives, features and advantages of the present invention, the scheme of the present invention will be further described below. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features therein can be combined with each other.

[0032] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present invention, rather than all the embodiments.

[0033] In order 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, rather than limiting the claims of the present invention.

[0034] Example 1

[0035] A method for preparing a high-efficiency hydrogenation catalyst comprises the following steps:

[0036] (1) A 40 wt% tetrapropylammonium hydroxide solution was mixed with 30 ml of deionized water and stirred for 20 min, and the concentration of the mixed solution was controlled to be 7.8 wt%. Tetraethyl orthosilicate was added, and the mass ratio of tetrapropylammonium hydroxide to tetraethyl orthosilicate was 0.2:1. The mixture was stirred at room temperature for 3 h. The obtained sol was transferred to a hydrothermal kettle and sealed. The mixture was reacted at 170 ° C for 40 h. After the reaction was completed, the mixture was cooled to room temperature. The reaction solution was filtered, the precipitate was dried, and placed in a muffle furnace. It was dried at 550 ° C for 5 h to obtain a silicate material.

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

[0038] (3) 0.02 g of 3-aminopropyltriethoxysilane was mixed with 100 ml of ethanol solution (the volume ratio of ethanol to deionized water was 9:1), and the hollow silicate material was added (the mass ratio of 3-aminopropyltriethoxysilane to the hollow silicate material was 0.01:1). The mixture was treated at 80°C for 5 h. After the treatment, the mixture was cooled to room temperature, the reaction solution was filtered, and the precipitate was dried to obtain a functionalized hollow silicate material.

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

[0040] (5) Nickel nitrate hexahydrate and titanium sulfate were dissolved in 40 ml of deionized water to obtain a mixed metal salt solution (the concentrations of nickel nitrate hexahydrate and titanium sulfate were 0.1 mol / ml and 0.09 mol / ml respectively); a cerium-loaded hollow silicate material was added to the mixed metal salt solution (the ratio of the cerium-loaded hollow silicate material to the mixed metal salt solution was 1 g:40 ml), and the mixture was stirred at room temperature for 30 min. Then, a sodium carbonate solution was added (the concentrations of sodium carbonate and sodium hydroxide in the solution were 0.12 g / ml and 0.1 g / ml respectively) to adjust the pH of the system to 10. The mixture was treated at 40°C for 10 h. After precipitation, the mixture was filtered and the precipitate was dried to obtain a catalyst precursor;

[0041] (6) 40 ml of ethanol and 10 ml of tetralin were mixed, sodium borohydride was added, and the mixture was stirred until dissolved to obtain a mixed solvent, wherein the concentration of sodium borohydride in the mixed solvent was 0.3 wt %. The above-mentioned catalyst precursor was added (the ratio of the catalyst precursor material to the mixed solvent was 1 g: 100 ml). The obtained mixed solution was transferred to an autoclave and sealed. The temperature of the autoclave was then raised to 180°C and the pressure was raised to 5 MPa. The mixture was pretreated for 20 min, and then the temperature was raised to 268°C at a rate of 2°C / min. The pressure was raised to 9 MPa and the mixture was treated again for 20 min. After the reaction was completed, the mixture was cooled to room temperature, the reaction solution was filtered, the precipitate was washed, and then dried to obtain a high-efficiency hydrogenation catalyst.

[0042] Example 2

[0043] A method for preparing a high-efficiency hydrogenation catalyst comprises the following steps:

[0044] (1) A 40 wt% tetrapropylammonium hydroxide solution was mixed with 30 ml of deionized water and stirred for 25 min, and the concentration of the solution obtained by mixing was controlled to be 7.9 wt%. Tetraethyl orthosilicate was added, and the mass ratio of tetrapropylammonium hydroxide to tetraethyl orthosilicate was 0.3:1. The mixture was stirred at room temperature for 3.5 h. The obtained sol was transferred to a hydrothermal kettle and sealed. The mixture was reacted at 170 ° C for 45 h. After the reaction was completed, the mixture was cooled to room temperature. The reaction solution was filtered, the precipitate was dried, and placed in a muffle furnace. It was dried at 550 ° C for 5.5 h to obtain a silicate material.

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

[0046] (3) 0.05 g of 3-aminopropyltriethoxysilane was mixed with 100 ml of ethanol solution (the volume ratio of ethanol to deionized water was 9:1), and the hollow silicate material was added (the mass ratio of 3-aminopropyltriethoxysilane to the hollow silicate material was 0.02:1). The mixture was treated at 80°C for 5.5 h. After the treatment, the mixture was cooled to room temperature, the reaction solution was filtered, and the precipitate was dried to obtain a functionalized hollow silicate material.

[0047] (4) 1 g of cerium nitrate hexahydrate and ascorbic acid were dissolved in 50 ml of deionized water to obtain a reduction system solution, and the functionalized hollow silicate material was added (the mass ratio of cerium nitrate hexahydrate, ascorbic acid, and functionalized hollow silicate material was 0.045:0.0045:1). The solution was subjected to reduction treatment at 58°C for 1.5 h. After the treatment, the solution was cooled to room temperature, filtered, and precipitated and dried to obtain the cerium-loaded hollow silicate material.

[0048] (5) Nickel nitrate hexahydrate and titanium sulfate were dissolved in 45 ml of deionized water to obtain a mixed metal salt solution (the concentrations of nickel nitrate hexahydrate and titanium sulfate were 0.12 mol / ml and 0.10 mol / ml respectively); a cerium-loaded hollow silicate material was added to the mixed metal salt solution (the ratio of the cerium-loaded hollow silicate material to the mixed metal salt solution was 1 g:45 ml), and the mixture was stirred at room temperature for 30 min. Then, a sodium carbonate solution was added (the concentrations of sodium carbonate and sodium hydroxide in the solution were 0.125 g / ml and 0.1 g / ml respectively) to adjust the pH of the system to 10. The mixture was treated at 40°C for 12 h. After precipitation, the mixture was filtered and the precipitate was dried to obtain a catalyst precursor.

[0049] (6) 40 ml of ethanol and 10 ml of tetralin were mixed, sodium borohydride was added, and the mixture was stirred until dissolved to obtain a mixed solvent, wherein the concentration of sodium borohydride in the mixed solvent was 0.35 wt%. The above-mentioned catalyst precursor was added (the ratio of the catalyst precursor material to the mixed solvent was 1 g: 100 ml). The obtained mixed solution was transferred to an autoclave and sealed. The temperature of the autoclave was then raised to 180°C and the pressure was raised to 5 MPa. The mixture was pretreated for 25 min, and then the temperature was raised to 268°C at a rate of 2°C / min. The pressure was raised to 9 MPa and the mixture was treated again for 25 min. After the reaction was completed, the mixture was cooled to room temperature, the reaction solution was filtered, the precipitate was washed, and then dried to obtain a high-efficiency hydrogenation catalyst.

[0050] Example 3

[0051] A method for preparing a high-efficiency hydrogenation catalyst comprises the following steps:

[0052] (1) A 40 wt% tetrapropylammonium hydroxide solution was mixed with 30 ml of deionized water and stirred for 30 min, and the concentration of the mixed solution was controlled to be 8.0 wt%. Tetraethyl orthosilicate was added, and the mass ratio of tetrapropylammonium hydroxide to tetraethyl orthosilicate was 0.4:1. The mixture was stirred at room temperature for 4 h. The obtained sol was transferred to a hydrothermal kettle and sealed. The mixture was reacted at 170 ° C for 50 h. After the reaction was completed, the mixture was cooled to room temperature. The reaction solution was filtered, the precipitate was dried, and placed in a muffle furnace. It was dried at 550 ° C for 6 h to obtain a silicate material.

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

[0054] (3) 0.1 g of 3-aminopropyltriethoxysilane was mixed with 100 ml of ethanol solution (the volume ratio of ethanol to deionized water was 9:1), and the hollow silicate material was added (the mass ratio of 3-aminopropyltriethoxysilane to the hollow silicate material was 0.05:1). The mixture was treated at 80°C for 6 h. After the treatment, the mixture was cooled to room temperature, the reaction solution was filtered, and the precipitate was dried to obtain a functionalized hollow silicate material.

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

[0056] (5) Nickel nitrate hexahydrate and titanium sulfate were dissolved in 50 ml of deionized water to obtain a mixed metal salt solution (the concentrations of nickel nitrate hexahydrate and titanium sulfate were 0.15 mol / ml and 0.12 mol / ml respectively); a cerium-loaded hollow silicate material was added to the mixed metal salt solution (the ratio of the cerium-loaded hollow silicate material to the mixed metal salt solution was 1 g:50 ml), and the mixture was stirred at room temperature for 30 min. Then, a sodium carbonate solution was added (the concentrations of sodium carbonate and sodium hydroxide in the solution were 0.13 g / ml and 0.11 g / ml respectively) to adjust the pH of the system to 10. The mixture was treated at 40°C for 15 h. After precipitation, the mixture was filtered and the precipitate was dried to obtain a catalyst precursor.

[0057] (6) 40 ml of ethanol and 10 ml of tetralin were mixed, sodium borohydride was added, and the mixture was stirred until dissolved to obtain a mixed solvent, wherein the concentration of sodium borohydride in the mixed solvent was 0.4 wt %. The above-mentioned catalyst precursor was added (the ratio of the catalyst precursor material to the mixed solvent was 1 g: 100 ml). The obtained mixed solution was transferred to an autoclave and sealed. The temperature of the autoclave was then raised to 180°C and the pressure was raised to 5 MPa. The autoclave was pretreated for 30 min, and then the temperature was raised to 268°C at a rate of 2°C / min, and the pressure was raised to 9 MPa for another 30 min. After the reaction was completed, the mixture was cooled to room temperature, the reaction solution was filtered, the precipitate was washed, and then dried 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, and other operations are the same as Example 3.

[0060] Comparative Example 2

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

[0062] Comparative Example 3

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

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

[0065] Table 1

[0066]

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

[0068] In Comparative Example 1, the hollow silicate material is not functionalized, resulting in the absence of active groups such as amino groups on the surface of the carrier, which cannot anchor the metal well, causing uneven loading of subsequent metal active components, and metal particles agglomerating and blocking part of the pores, thereby reducing the specific surface area and pore volume of the obtained high-efficiency hydrogenation catalyst. At the same time, the average pore size increases due to the blockage of the small pores. In Comparative Example 2, no metal cerium is loaded, and the carrier pores are not filled with Ce, resulting in more pores of the high-efficiency hydrogenation catalyst, and the specific surface area and pore volume of the high-efficiency hydrogenation catalyst are higher than those in Example 3. In Comparative Example 3, high temperature and high pressure treatment is directly carried out, resulting in too fast reduction of the metal ions nickel and titanium, sintering and aggregation of the metal particles, causing part of the pores to be blocked, and the specific surface area and pore volume of the obtained high-efficiency hydrogenation catalyst are significantly reduced.

[0069] Application Example 1

[0070] The application of a high-efficiency hydrogenation catalyst in the synthesis of γ-butyrolactone comprises the following steps:

[0071] S1. 10 g of the high-efficiency hydrogenation catalyst of Example 1 was mixed with 1000 ml of 5 wt% H2SO4, and the mixture was impregnated at room temperature for 1-2 h. After the impregnation, the mixture was filtered and the precipitate was dried to obtain an acidified catalyst.

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

[0073] S3. Hydrogen was introduced into the primary fixed-bed reactor and the secondary fixed-bed reactor respectively, with the hydrogen flow rate controlled at 50 ml / min, and the catalyst in the primary fixed-bed reactor was activated at 200° C. for 2 h, and the catalyst in the secondary fixed-bed reactor was activated at 150° C. for 2 h;

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

[0075] S5. Pump the maleic anhydride solution into a first-stage fixed-bed reactor for a hydrogenation reaction. Control the temperature of the hydrogenation reaction to be 140° C., the reaction pressure to be 3.0 MPa, and the mass space velocity of the maleic anhydride solution to be 1.0 h -1 , the hydrogen-oil ratio is 200:1; the liquid after the reaction in the first fixed bed reactor is pumped into the second fixed bed reactor for secondary hydrogenation reaction. The temperature of the secondary hydrogenation reaction is controlled to be 200 ° C, the reaction pressure is 5.0 MPa, and the mass space velocity of the liquid after the reaction is 0.5h -1 , hydrogen-to-oil ratio is 250:1;

[0076] S6. After the reaction liquid in the secondary fixed-bed reactor is cooled to room temperature, it is first subjected to reduced pressure distillation at 50°C and 10 kPa to remove ethanol, and then to reduced pressure distillation at 80°C and 5 kPa to recover the target product.

[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 to replace the high-efficiency hydrogenation catalyst of Example 1, and other operations are the same as those of 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 to replace the high-efficiency hydrogenation catalyst of Example 1, and other operations are the same as those of Application Example 1.

[0081] Comparative Application 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 to replace the high-efficiency hydrogenation catalyst of Example 1, and other operations are the same as those of Application Example 1.

[0083] Application Comparative Example 2

[0084] The difference from Application Example 1 is that the high-efficiency hydrogenation catalyst of Comparative Example 2 is used in equal amounts to replace the high-efficiency hydrogenation catalyst of Example 1, and the other operations are the same as those of 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 to replace the high-efficiency hydrogenation catalyst of Example 1, and other operations are the same as those of Application Example 1.

[0086] Comparative Application Example 4

[0087] The difference from Application Example 1 is that step S1 is not included, and 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 those in Application Example 1.

[0088] Application Comparative Example 5

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

[0090] After testing, in the above application example, the purity and single yield of the target product γ-butyrolactone when the hydrogenation process was continuously tested for 1000 hours are shown in Table 2.

[0091] Single yield (%) = [(single actual yield of γ-butyrolactone × γ-butyrolactone purity) / (single theoretical yield of γ-butyrolactone)] × 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 Comparative Application Example 1 94.5 92.3 Application Comparative Example 2 96.1 94.5 Application Comparative Example 3 95.2 92.9 Comparative Application 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 embodiment of the present invention has a large specific surface area, good dispersibility of the loaded metal active component, high catalytic activity, and the purity of the target product γ-butyrolactone obtained reaches more than 99%, and the product yield reaches more than 97%. However, the catalyst specific surface area and the dispersibility of the metal active component of Comparative Examples 1-3 are reduced, and the purity and yield of the target product γ-butyrolactone obtained by catalysis thereof are significantly reduced. In Comparative Example 4, the high-efficiency hydrogenation catalyst is not acidified, and the catalyst has few acid sites, which cannot well promote the cyclization reaction in the secondary hydrogenation, resulting in a decrease in the purity and yield of the target product. In Comparative Example 5, the catalyst is not activated, resulting in insufficient activity and stability of the catalyst, and especially the purity and yield of the target product obtained by catalysis are also reduced.

[0095] Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas, including the best mode, and also enable any technician in the field to practice the present invention, including making and using any device or system, and implementing any combined method. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. The scope of patent protection of the present invention is defined by the claims and may include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements similar to the literal description of the claims, or if they include equivalent structural elements that are not substantially different from the literal description of the claims, then these other embodiments should also be included in the scope of the claims.

Claims

1. A method for preparing a high-efficiency hydrogenation catalyst, characterized in that: The following steps are involved: (1) Using tetrapropylammonium hydroxide as a template and ethyl orthosilicate as a silicon source, a silicate is prepared by a hydrothermal reaction, and then treated with an alkali to obtain a hollow silicate material; (2) treating the hollow silicate carrier with 3-aminopropyltriethoxysilane to obtain a functionalized hollow silicate material; (3) using the functionalized hollow silicate material as a carrier, loading cerium by an in-situ impregnation reduction method, and then adding it to a mixed metal salt solution of nickel nitrate hexahydrate and titanium sulfate for co-precipitation to obtain a catalyst precursor; (4) Ethanol and tetralin are mixed, sodium borohydride is added, and the mixture is stirred until dissolved to obtain a mixed solvent. A catalyst precursor is added, and the obtained mixed solution is transferred to an autoclave and sealed. The autoclave is then heated and pressurized once for pretreatment, and then heated and pressurized again for secondary treatment. After the reaction is completed, the mixture is cooled to room temperature, the reaction solution is filtered, the precipitate is washed, and then dried to obtain a high-efficiency hydrogenation catalyst.

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

3. The method for preparing a high-efficiency hydrogenation catalyst according to claim 1, wherein In step (1), the precipitate after the hydrothermal reaction is dried and then calcined once, then treated with alkali, and finally calcined twice; The primary calcination temperature is 520-570°C and the time is 5-6 hours; During the alkali treatment, tetrapropylammonium hydroxide solution is used as a solvent, the concentration of the tetrapropylammonium hydroxide solution is 30-35 wt%, and the ratio of the primary calcined powder to the tetrapropylammonium hydroxide solution is 1 g: (7-10 ml). The alkali treatment temperature is 170° C. and the treatment time is 20-30 h. The secondary calcination temperature is 520-570°C and the time is 5-6 hours.

4. The method for preparing a high-efficiency hydrogenation catalyst according to claim 1, wherein In step (2), the mass ratio of 3-aminopropyltriethoxysilane to the hollow silicate carrier is (0.01-0.05):1; the temperature during treatment is 80° C. and the treatment time is 5-6 hours.

5. The method for preparing a high-efficiency hydrogenation catalyst according to claim 1, wherein In step (3), the cerium source during the in-situ immersion reduction treatment is cerium nitrate hexahydrate, the reducing agent is ascorbic acid, 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 immersion reduction treatment is 55-60°C, and the time is 1-2h.

6. The method for preparing a high-efficiency hydrogenation catalyst according to claim 1, wherein: 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 cerium-loaded hollow silicate material to the mixed metal salt solution is 1 g: (40-50) ml.

7. The method for preparing a high-efficiency hydrogenation catalyst according to claim 1, wherein: In step (3), 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, the sodium carbonate solution is added to adjust the pH of the system to 10, and the coprecipitation treatment temperature is 40° C. and the time is 10-15 hours.

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

9. The method for preparing a high-efficiency hydrogenation catalyst according to claim 1, wherein: The pretreatment is to raise the temperature of the autoclave to 180°C and the pressure to 5MPa for 20-30min. The secondary treatment is to raise the temperature to 268°C at a rate of 2°C / min and raise the pressure to 9MPa for 20-30min.

10. Use of a high-efficiency hydrogenation catalyst prepared by the method according to any one of claims 1 to 9 in the synthesis of γ-butyrolactone, characterized in that: The following steps are involved: S1. Immerse the high-efficiency hydrogenation catalyst in 5 wt% H2SO4 for 1-2 h to obtain an acidified catalyst; S2. Loading a high-efficiency hydrogenation catalyst and an acidification catalyst into the primary fixed-bed reactor and the secondary fixed-bed reactor, respectively, controlling the loading volumes of the high-efficiency hydrogenation catalyst and the acidification catalyst to be 5 ml and 5 ml; S3. Hydrogen was introduced into the primary fixed-bed reactor and the secondary fixed-bed reactor respectively, with the hydrogen flow rate controlled at 50 ml / min, and the catalyst in the primary fixed-bed reactor was activated at 200° C. for 2 h, and the catalyst in the secondary fixed-bed reactor was 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. Pump the maleic anhydride solution into a first-stage fixed-bed reactor for a hydrogenation reaction. Control the temperature of the hydrogenation reaction to be 140° C., the reaction pressure to be 3.0 MPa, and the mass space velocity of the maleic anhydride solution to be 1.0 h -1 , the hydrogen-oil ratio is 200:1; the liquid after the reaction in the first fixed bed reactor is pumped into the second fixed bed reactor for secondary hydrogenation reaction. The temperature of the secondary hydrogenation reaction is controlled to be 200 ° C, the reaction pressure is 5.0 MPa, and the mass space velocity of the liquid after the reaction is 0.5h -1 , hydrogen-to-oil ratio is 250:1; S6. After the reaction liquid in the secondary fixed-bed reactor is cooled to room temperature, it is first subjected to reduced pressure distillation at 50°C and 10 kPa to remove ethanol, and then to reduced pressure distillation at 80°C and 5 kPa to recover the target product.

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