Dehydrogenation catalyst, its synthesis method and application
CuO, ZnO, and Al2O3 catalysts were prepared by coaxial electrospinning and calcination techniques, which solved the problem of unstable metal dispersion in Cu-based catalysts during the dehydrogenation of 1,4-butanediol and achieved high conversion and selectivity in the production of γ-butyrolactone.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA PETROLEUM & CHEMICAL CORP
- Filing Date
- 2024-12-09
- Publication Date
- 2026-06-09
Smart Images
Figure BDA0005178265420000101
Abstract
Description
Technical Field
[0001] This invention belongs to the field of catalyst technology, and relates to a dehydrogenation catalyst, its synthesis method and application. Background Technology
[0002] Gamma-butyrolactone (GBL) is an important organic chemical product and intermediate. GBL and its derivatives are widely used in petrochemicals, pharmaceuticals, pesticides, and fine chemicals. In recent years, with the rapid development of the biodegradable plastics industry and the new energy battery industry, the demand for GBL has been increasing year by year. Industrially, the main methods for preparing GBL include the maleic anhydride hydrogenation method and the 1,4-butanediol (BDO) dehydrogenation method. Due to its advantages in raw material and product separation, the 1,4-butanediol dehydrogenation method has gradually become the mainstream method for industrial GBL preparation.
[0003] CN117186037A discloses a catalyst for the dehydrogenation of 1,4-butanediol to prepare γ-butyrolactone, its preparation method, and its application. The catalyst consists of a support, an active component (15-30%), and an auxiliary agent (0.5-3%). The active component is Cu and Ce, and the auxiliary agent is at least one selected from K, Mg, Mn, and Zr. The support is a carbon support. The BDO conversion rate is 91.7%-96.6%, and the GBL selectivity is 92.1%-96.4%.
[0004] CN116272984A discloses a catalyst, preparation method, and application for the dehydrogenation of 1,4-butanediol to prepare γ-butyrolactone. The catalyst consists of a support, an active component (3-8%), and an auxiliary agent (0.5-3%). The active component is Ag, and the auxiliary agent is at least one of K and La. The support is a mixture of a carbon support and a metal oxide support. The metal oxide support is any one of MgO, CaO, MnO, and CeO2. The BDO conversion rate is 91.8%-95.6%, and the GBL selectivity is 91.7%-95.2%.
[0005] Currently, some progress has been made in the development of Cu-based catalysts for the dehydrogenation of 1,4-butanediol to prepare γ-butyrolactone. However, during the synthesis of the catalyst, the precipitation sequence of metal ions is uncontrollable, and the active sites are easily covered by the support, resulting in unstable parameters such as catalyst specific surface area, acid content, and metal dispersion. This can easily lead to problems such as copper sintering, excessive acid content, and coverage of active sites during the catalytic reaction, thereby affecting the conversion rate and selectivity of the catalyst. Summary of the Invention
[0006] To address the shortcomings of existing technologies, this invention provides a dehydrogenation catalyst, its synthesis method, and its application. The catalyst obtained by the method of this invention exhibits high conversion and selectivity in the dehydrogenation of 1,4-butanediol to γ-butyrolactone.
[0007] The first aspect of this invention provides a method for synthesizing a dehydrogenation catalyst, comprising:
[0008] (1) Soluble copper salt, soluble zinc salt and soluble aluminum salt are mixed with dichloromethane and ethanol to obtain a mixed solution containing copper, zinc and aluminum. Polylactic acid is then added and stirred to obtain a spinning solution.
[0009] (2) Using a coaxial electrospinning nozzle, electrospinning is performed with the spinning solution obtained in step (1), and the resulting solid is collected.
[0010] (3) The solid obtained in step (2) is placed in an ethanol solution of pyromellitic acid and reacted. After the reaction is completed, it is washed and dried to obtain the catalyst precursor.
[0011] (4) The catalyst precursor obtained in step (3) is calcined and post-treated to obtain the catalyst.
[0012] Further, in step (1), the soluble copper salt is one or more of copper nitrate trihydrate, copper sulfate, copper chloride, and copper acetate. The soluble zinc salt is one or more of zinc nitrate hexahydrate, zinc sulfate, zinc chloride, and zinc acetate. The soluble aluminum salt is one or more of aluminum nitrate nonahydrate, aluminum sulfate, and aluminum chloride.
[0013] Further, in step (1), the concentration of soluble copper salt in the mixed solution of copper, zinc and aluminum is 0.01-0.2 mol / L, the concentration of soluble zinc salt is 0.01-0.2 mol / L, and the concentration of soluble aluminum salt is 0.01-0.15 mol / L.
[0014] Further, in step (1), the volume ratio of dichloromethane to ethanol is (1-5):1.
[0015] Further, in step (1), the molecular weight of polylactic acid is 80,000 to 200,000, and the concentration of polylactic acid in the spinning solution is 0.03 to 0.3 g / mL.
[0016] Further, in step (1), the stirring conditions are: stirring speed of 100 to 1500 rpm and stirring time of 2 to 24 hours.
[0017] Further, in step (2), the conditions for electrospinning are: spinning voltage of 15-30kV, feed speed of 0.5-2.0mL / h, and receiving distance of 10-20cm.
[0018] Further, in step (2), the internal needle size of the coaxial electrospinning nozzle is 14-20G, and the external needle size is 19-25G, wherein the internal needle size is smaller than the external needle size.
[0019] Further, in step (3), the concentration of pyromellitic acid in the ethanol solution of pyromellitic acid is 0.01 to 1.0 mol / L.
[0020] Furthermore, in step (3), the concentration of the solid obtained in step (2) in the pyromellitic acid ethanol solution is 0.02 to 0.2 g / mL.
[0021] Furthermore, in step (3), the reaction conditions are: reacting at 25–80°C for 0.5–5 h.
[0022] Further, in step (3), the washing process involves first washing with ethanol 1 to 3 times, and then washing with deionized water 1 to 3 times.
[0023] Furthermore, in step (3), the drying conditions are as follows: the drying temperature is 25-80℃, and the drying time is 6-24h.
[0024] Further, in step (4), the calcination conditions are: calcination at 300–500°C for 2–6 hours. The calcination can be carried out using a programmed temperature increase at a rate of 2–10°C / min, and the calcination atmosphere is an oxygen-containing atmosphere, such as air.
[0025] Furthermore, in step (4), the post-processing includes processes such as tableting, crushing, and sieving. The post-processing can be carried out using conventional methods in the art. An appropriate amount of graphite may be added during the tableting process. The crushing and sieving involves sieving particles of 20-40 mesh.
[0026] A second aspect of the present invention provides a dehydrogenation catalyst prepared by the above method.
[0027] Furthermore, the catalyst comprises CuO, ZnO, and Al2O3.
[0028] Furthermore, based on the weight of the catalyst, the weight contents of each component are as follows: CuO 30%–60%, ZnO 30%–60%, Al2O3 5%–30%.
[0029] Furthermore, the catalyst also contains a forming aid, such as graphite, which accounts for less than 8% by weight in the catalyst, and more specifically 0.1% to 8%.
[0030] Furthermore, the total acidity of the catalyst is 0.10–0.40 mmol / g, preferably 0.10–0.30 mmol / g.
[0031] Furthermore, the catalyst is tested by H2-N2O titration, and the dispersion of metallic Cu is 35% to 70%, such as, but not limited to, 35%, 38%, 40%, 42%, 45%, 48%, 50%, 52%, 55%, 58%, 60%, 65%, 70%, etc., and any value within the range formed by any two of these values.
[0032] Furthermore, the specific surface area of the catalyst is 80–150 m². 2 / g, pore volume 0.15~0.70cm³ 3 / g, with an average pore size of 10–30 nm.
[0033] A third aspect of the present invention provides the application of the above-mentioned dehydrogenation catalyst in the dehydrogenation of 1,4-butanediol to γ-butyrolactone.
[0034] Furthermore, the catalyst needs to be reduced before the reaction. The preferred reducing atmosphere is hydrogen, and the reduction conditions are as follows: hydrogen pressure is 0-0.5 MPa, reduction temperature is 150-300℃, and reduction time is 6-24 h.
[0035] Furthermore, the application includes: reacting 1,4-butanediol with the catalyst in the presence of hydrogen to produce γ-butyrolactone.
[0036] Further, the reaction conditions are as follows: reaction temperature is 150–300℃, preferably 215–230℃; reaction pressure is 0.1–1.0 MPa, preferably 0.1–0.5 MPa; and volume hourly space velocity is 0.1–2.0 h⁻¹. -1 Preferably, it is 0.3 to 1.5 hours. -1 The molar ratio of hydrogen to 1,4-butanediol is 1 to 150:1, preferably 1 to 30:1.
[0037] Compared with the prior art, the present invention has the following advantages:
[0038] (1) The catalyst of the present invention has high conversion rate and selectivity in the dehydrogenation of 1,4-butanediol to γ-butyrolactone.
[0039] (2) In the preparation method of the catalyst of the present invention, the specific surface area of the catalyst is increased by using coaxial electrospinning technology, which provides abundant mass transfer channels for reactants to enter the catalyst. At the same time, the active metal Cu is fixed by pyromellitic acid, and the heterogeneous interface between different components provides abundant active sites, which also improves the metal dispersion. This is beneficial to improving the reaction conversion rate and selectivity of the catalyst in the dehydrogenation of 1,4-butanediol to γ-butyrolactone. Detailed Implementation
[0040] The technical solution of the present invention will be described in detail below with reference to the embodiments, but the present invention is not limited to the following embodiments. In the present invention, wt% is a mass fraction.
[0041] In this invention, an ASAP 2425 (McClone Systems, Inc., USA) physical adsorption analyzer was used to test specific surface area, pore volume, and pore size. Specific surface area was analyzed using the BET method; pore size distribution was calculated using BJH and DFT theoretical models based on the adsorption data.
[0042] In this invention, a PANalytical Axios X-ray fluorescence spectrometer was used to analyze the types and contents of elements.
[0043] In this invention, the acidity of the catalyst was analyzed by temperature-programmed desorption of NH3 using a Sennheiser 5080B chemisorption analyzer and a mass spectrometer (Hiden DECRA, UK).
[0044] In this invention, the metal dispersion was tested using an AutoChem II 2920 (McClone Systems, Inc., USA) chemisorption analyzer via H2-N2O titration. The specific test method is as follows:
[0045] (a) Weigh 100 mg of the catalyst sample to be tested and place it in a U-shaped quartz tube. Pre-treat it at 450 °C for 1 h under an inert atmosphere, and then cool it to room temperature. Under a mixed atmosphere of 10% H2 / 90% Ar by volume, raise the temperature to 800 °C at a rate of 10 °C / min and measure the amount of H2 consumed, X, to determine the total number of Cu atoms in the catalyst sample.
[0046] (b) The reduced catalyst was purged and cooled to 50°C under an inert atmosphere. The volume fraction was changed to 10% N2O / 90% Ar and reacted for 1 h. The metal Cu on the surface of the catalyst sample was oxidized to Cu2O (2Cu+N2O→Cu2O+N2). Then, the residual N2O was purged clean under an inert atmosphere.
[0047] (c) After the oxidation step, a H2 programmed temperature reduction process is carried out. Under a mixed atmosphere of 10% H2 / 90% Ar by volume, the temperature is increased to 800℃ at a rate of 10℃ / min. The amount of H2 consumed, Y, is measured to determine the number of Cu atoms on the surface of the catalyst sample.
[0048] The formula for calculating the dispersion of metallic Cu is: Dispersion (%) = 2Y / X × 100%.
[0049] Example 1
[0050] (1) Cu(NO3)2·3H2O, Zn(NO3)2·6H2O and Al(NO3)3·9H2O were added to 15mL of dichloromethane and 5mL of anhydrous ethanol to prepare a mixed solution containing copper, zinc and aluminum. The concentration of copper salt in the mixed solution was 0.1mol / L, the concentration of zinc salt was 0.1mol / L and the concentration of aluminum salt was 0.04mol / L. 1.5g of polylactic acid (PLA, molecular weight 160000) was added to the solution and the mixture was magnetically stirred at 1000rpm for 12h to obtain a spinning solution.
[0051] (2) Using a coaxial electrospinning nozzle (inner needle model 16G, outer needle model 21G), with the spinning solution obtained in step (1) as the shell, electrospinning is performed according to the following parameters: the spinning voltage is controlled at 20kV, the feed speed is 2.0mL / h, and the receiving distance is 15cm.
[0052] (3) Place 5g of the solid obtained in step (2) into 50mL of ethanol solution of pyromellitic acid (the concentration of pyromellitic acid is 0.1mol / L), react at 50℃ for 2h, wash with ethanol 3 times and deionized water 3 times after the reaction is completed, and dry at 50℃ for 12h to obtain the catalyst precursor.
[0053] (4) The catalyst precursor obtained in step (3) is placed in a muffle furnace for calcination under the following conditions: the calcination temperature rise rate is 5℃ / min to 400℃, and calcination is carried out at 400℃ for 4 hours. The calcination atmosphere is air. Graphite is added to the obtained catalyst powder, which is then pressed into tablets, pulverized, and sieved to obtain 20-40 mesh particles to form catalyst A1. The properties of catalyst A1 are shown in Table 1.
[0054] Example 2
[0055] (1) Cu(NO3)2·3H2O, Zn(NO3)2·6H2O and Al(NO3)3·9H2O were added to 15mL of dichloromethane and 5mL of anhydrous ethanol to prepare a mixed solution containing copper, zinc and aluminum. The concentration of copper salt in the mixed solution was 0.1mol / L, the concentration of zinc salt was 0.1mol / L and the concentration of aluminum salt was 0.04mol / L. 3g of polylactic acid (molecular weight 160000) was added and the mixture was stirred at 1000rpm for 12h to obtain the spinning solution.
[0056] (2) Using a coaxial electrospinning nozzle (inner needle model 16G, outer needle model 21G), with the spinning solution obtained in step (1) as the shell, electrospinning is performed according to the following parameters: the spinning voltage is controlled at 20kV, the feed speed is 2.0mL / h, and the receiving distance is 15cm.
[0057] (3) Place 5g of the solid obtained in step (2) into 50mL of ethanol solution of pyromellitic acid (0.1mol / L), react at 50℃ for 2h, wash with ethanol 3 times and deionized water 3 times after the reaction, and dry at 50℃ for 12h to obtain the catalyst precursor.
[0058] (4) The catalyst precursor obtained in step (3) is placed in a muffle furnace for calcination under the following conditions: the calcination temperature rise rate is 5℃ / min to 400℃, and calcination is carried out at 400℃ for 4 hours in an air atmosphere. Graphite is added to the obtained catalyst powder, which is then pressed into tablets, pulverized, and sieved to obtain 20-40 mesh particles to form catalyst A2. The properties of catalyst A2 are shown in Table 1.
[0059] Example 3
[0060] (1) Cu(NO3)2·3H2O, Zn(NO3)2·6H2O and Al(NO3)3·9H2O were added to 15mL of dichloromethane and 5mL of anhydrous ethanol to prepare a mixed solution containing copper, zinc and aluminum. The concentration of copper salt in the mixed solution was 0.2mol / L, the concentration of zinc salt was 0.2mol / L and the concentration of aluminum salt was 0.08mol / L. 1.5g of polylactic acid (molecular weight 160000) was added to the solution and stirred at 1000rpm for 12h to obtain a spinning solution.
[0061] (2) Using a coaxial electrospinning nozzle (inner needle model 16G, outer needle model 21G), with the spinning solution obtained in step (1) as the shell, electrospinning is performed according to the following parameters: the spinning voltage is controlled at 20kV, the feed speed is 2.0mL / h, and the receiving distance is 15cm.
[0062] (3) Place 5g of the solid obtained in step (2) into 50mL of ethanol solution of pyromellitic acid (0.1mol / L), react at 50℃ for 2h, wash with ethanol 3 times and deionized water 3 times after the reaction, and dry at 50℃ for 12h to obtain the catalyst precursor.
[0063] (4) The catalyst precursor obtained in step (3) is placed in a muffle furnace for calcination under the following conditions: the calcination temperature rise rate is 5℃ / min to 350℃, and calcination is carried out at 400℃ for 4 hours. The calcination atmosphere is air. Graphite is added to the obtained catalyst powder, which is then pressed into tablets, pulverized, and sieved to obtain 20-40 mesh particles to form catalyst A3. The properties of catalyst A3 are shown in Table 1.
[0064] Example 4
[0065] (1) Cu(NO3)2·3H2O, Zn(NO3)2·6H2O and Al(NO3)3·9H2O were added to 15mL of dichloromethane and 5mL of anhydrous ethanol to prepare a mixed solution containing copper, zinc and aluminum. The concentration of copper salt in the mixed solution was 0.1mol / L, the concentration of zinc salt was 0.1mol / L and the concentration of aluminum salt was 0.04mol / L. 1.5g of polylactic acid (molecular weight 160000) was added to the solution and stirred at 1000rpm for 12h to obtain the spinning solution.
[0066] (2) Using a coaxial electrospinning nozzle (inner needle model 17G, outer needle model 22G), with the spinning solution obtained in step (1) as the shell, electrospinning is performed according to the following parameters: the spinning voltage is controlled at 15kV, the feed speed is 1.5mL / h, and the receiving distance is 10cm.
[0067] (3) Place 5g of the solid obtained in step (2) into 50mL of ethanol solution of pyromellitic acid (the concentration of pyromellitic acid is 0.1mol / L), react at 50℃ for 2h, wash with ethanol 3 times and deionized water 3 times after the reaction is completed, and dry at 50℃ for 12h to obtain the catalyst precursor.
[0068] (4) The catalyst precursor obtained in step (3) is placed in a muffle furnace for calcination under the following conditions: the calcination temperature rise rate is 5℃ / min to 400℃, and calcination is carried out at 400℃ for 4 hours in an air atmosphere. Graphite is added to the obtained catalyst powder, which is then pressed into tablets, pulverized, and sieved to obtain 20-40 mesh particles to form catalyst A4. The properties of catalyst A4 are shown in Table 1.
[0069] Example 5
[0070] (1) Cu(NO3)2·3H2O, Zn(NO3)2·6H2O and Al(NO3)3·9H2O were added to 15mL of dichloromethane and 5mL of anhydrous ethanol to prepare a mixed solution containing copper, zinc and aluminum. The concentration of copper salt in the mixed solution was 0.1mol / L, the concentration of zinc salt was 0.1mol / L and the concentration of aluminum salt was 0.04mol / L. 1.5g of polylactic acid (molecular weight 160000) was added to the solution and stirred at 1000rpm for 12h to obtain the spinning solution.
[0071] (2) Using a coaxial electrospinning nozzle (inner needle model 16G, outer needle model 21G), with the spinning solution obtained in step (1) as the shell, electrospinning is performed according to the following parameters: the spinning voltage is controlled at 20kV, the feed speed is 2.0mL / h, and the receiving distance is 15cm.
[0072] (3) Place 5g of the solid obtained in step (2) into 50mL of ethanol solution of pyromellitic acid (the concentration of pyromellitic acid is 0.05mol / L), react at 50℃ for 2h, wash with ethanol 3 times and deionized water 3 times after the reaction is completed, and dry at 50℃ for 12h to obtain the catalyst precursor.
[0073] (4) The catalyst precursor obtained in step (3) is placed in a muffle furnace for calcination under the following conditions: the calcination temperature rise rate is 5℃ / min to 400℃, and calcination is carried out at 400℃ for 4 hours in an air atmosphere. Graphite is added to the obtained catalyst powder, which is then pressed into tablets, pulverized, and sieved to obtain 20-40 mesh particles to form catalyst A5. The properties of catalyst A5 are shown in Table 1.
[0074] Comparative Example 1
[0075] (1) Cu(NO3)2·3H2O, Zn(NO3)2·6H2O and Al(NO3)3·9H2O were added to 15mL of dichloromethane and 5mL of anhydrous ethanol to prepare a 0.1mol / L copper salt, 0.1mol / L zinc salt and 0.04mol / L aluminum salt solution. 1.5g of polylactic acid (molecular weight 160000) was added to the solution and stirred at 1000rpm for 12h to obtain the spinning solution.
[0076] (2) Use a common single-channel electrospinning nozzle (needle model 21G) to perform electrospinning according to the following parameters: the spinning voltage is controlled at 20kV, the feed speed is 2.0mL / h, and the receiving distance is 15cm.
[0077] (3) Place 5g of the solid obtained in step (2) into 50mL of ethanol solution of trimesic acid (0.1M), react at 50℃ for 2h, wash with ethanol 3 times and deionized water 3 times after the reaction is completed, and dry at 50℃ for 12h to obtain the catalyst precursor.
[0078] (4) The catalyst precursor obtained in step (3) is placed in a muffle furnace for calcination under the following conditions: the calcination temperature rise rate is 5℃ / min to 400℃, and calcination is carried out at 400℃ for 4 hours in an air atmosphere to obtain unformed catalyst B1. Graphite is added to the catalyst powder, and after pressing, pulverizing, and sieving, 20-40 mesh particles are obtained to form catalyst B1. The properties of catalyst B1 are shown in Table 1.
[0079] Comparative Example 2
[0080] (1) Cu(NO3)2·3H2O, Zn(NO3)2·6H2O and Al(NO3)3·9H2O were added to 15mL of dichloromethane and 5mL of anhydrous ethanol to prepare a 0.1mol / L copper salt, 0.1mol / L zinc salt and 0.04mol / L aluminum salt solution. 1.5g of polylactic acid (molecular weight 160000) was added to the solution and stirred at 1000rpm for 12h to obtain the spinning solution.
[0081] (2) Using a coaxial electrospinning nozzle (inner needle model 16G, outer needle model 21G), with the spinning solution obtained in step (1) as the shell, electrospinning is performed according to the following parameters: the spinning voltage is controlled at 20kV, the feed speed is 2.0mL / h, and the receiving distance is 15cm.
[0082] (3) The catalyst precursor obtained in step (2) was placed in a muffle furnace for calcination under the following conditions: the calcination temperature was increased at a rate of 5℃ / min to 400℃, and calcined at 400℃ for 4 hours in an air atmosphere to obtain unformed catalyst B2. Graphite was added to the catalyst powder, and after pressing, pulverizing, and sieving to obtain 20-40 mesh particles, the formed catalyst B2 was obtained. The properties of catalyst B2 are shown in Table 1.
[0083] Application examples
[0084] The catalysts prepared in Examples 1-5 and Comparative Examples 1-2 were used for the atmospheric dehydrogenation of 1,4-butanediol to γ-butyrolactone. Before use, the catalysts were reduced with hydrogen under the following conditions: hydrogen pressure 0.1 MPa, reduction temperature 270 °C, and reduction time 12 h. After reduction, the reaction was carried out under the following conditions: reaction temperature 220 °C; feed hourly space velocity 1.0 h⁻¹. -1 The H2 / alcohol molar ratio was 5:1. The reaction results are shown in Table 2.
[0085] Table 1. Composition and physicochemical properties of each catalyst example.
[0086]
[0087] Table 2 Evaluation results of each catalyst
[0088] Catalyst number A1 A2 A3 A4 A5 B1 B2 1,4-Butanediol conversion rate (%) 99.87 99.91 99.64 99.72 99.38 98.19 96.31 γ-Butyrolactone selectivity (%) 98.33 97.69 98.76 98.17 98.21 95.02 98.02
[0089] It should be emphasized that the above-mentioned content is only a specific embodiment of the present invention and should not be construed as limiting the present invention to the above description in specific implementation. For those skilled in the art, any simple deductions and improvements made without departing from the spirit and principles of the present invention should be considered within the scope of protection of the present invention.
Claims
1. A method for synthesizing a dehydrogenation catalyst, characterized in that, include: (1) Soluble copper salt, soluble zinc salt and soluble aluminum salt are mixed with dichloromethane and ethanol to obtain a mixed solution containing copper, zinc and aluminum. Polylactic acid is then added and stirred to obtain a spinning solution. (2) Using a coaxial electrospinning nozzle, electrospinning is performed with the spinning solution obtained in step (1), and the resulting solid is collected. (3) The solid obtained in step (2) is placed in an ethanol solution of pyromellitic acid and reacted. After the reaction is completed, it is washed and dried to obtain the catalyst precursor. (4) The catalyst precursor obtained in step (3) is calcined and post-treated to obtain the catalyst.
2. The method according to claim 1, characterized in that, In step (1), the concentration of soluble copper salt in the mixed solution of copper, zinc and aluminum is 0.01-0.2 mol / L, the concentration of soluble zinc salt is 0.01-0.2 mol / L, and the concentration of soluble aluminum salt is 0.01-0.15 mol / L. Preferably, the soluble copper salt is one or more of copper nitrate trihydrate, copper sulfate, copper chloride, and copper acetate; and / or, the soluble zinc salt is one or more of zinc nitrate hexahydrate, zinc sulfate, zinc chloride, and zinc acetate; and / or, the soluble aluminum salt is one or more of aluminum nitrate nonahydrate, aluminum sulfate, and aluminum chloride.
3. The method according to claim 1, characterized in that, In step (1), the volume ratio of dichloromethane to ethanol is (1-5):1; And / or, in step (1), the molecular weight of the polylactic acid is 80,000 to 200,000; and the concentration of the polylactic acid in the spinning solution is 0.03 to 0.3 g / mL. And / or, in step (1), the stirring conditions are: stirring speed of 100 to 1500 rpm and stirring time of 2 to 24 hours.
4. The method according to claim 1, characterized in that, In step (2), the conditions for electrospinning are: spinning voltage of 15-30kV, feed speed of 0.5-2.0mL / h, and receiving distance of 10-20cm.
5. The method according to claim 1, characterized in that, In step (2), the internal needle size of the coaxial electrospinning nozzle is 14-20G, and the external needle size is 19-25G, wherein the internal needle size is smaller than the external needle size.
6. The method according to claim 1, characterized in that, In step (3), the concentration of pyromellitic acid in the ethanol solution of pyromellitic acid is 0.01 to 1.0 mol / L; And / or, the concentration of the solid obtained in step (2) in the pyromellitic acid ethanol solution is 0.02 to 0.2 g / mL.
7. The method according to claim 1, characterized in that, In step (3), the reaction conditions are: reaction at 25-80°C for 0.5-5 hours; and / or, in step (3), the drying conditions are as follows: drying temperature is 25-80°C, and drying time is 6-24 hours.
8. The method according to claim 1, characterized in that, In step (4), the calcination conditions are: calcination at 300-500℃ for 2-6 hours; the calcination preferably adopts programmed heating with a heating rate of 2-10℃ / min, and the calcination atmosphere is an oxygen-containing atmosphere.
9. A dehydrogenation catalyst prepared by the method according to any one of claims 1-8.
10. The catalyst according to claim 9, characterized in that, The catalyst includes CuO, ZnO, and Al2O3; And / or, based on the weight of the catalyst, the weight contents of each component are as follows: CuO 30%–60%, ZnO 30%–60%, Al2O3 5%–30%.
11. The catalyst according to claim 9, characterized in that, The total acidity of the catalyst is 0.10–0.40 mmol / g, preferably 0.10–0.30 mmol / g; And / or, the catalyst, as determined by H2-N2O titration, shows a Cu dispersion of 35% to 70%; And / or, the specific surface area of the catalyst is 80–150 m². 2 / g, pore volume 0.15~0.70cm³ 3 / g, with an average pore size of 10–30 nm.
12. The use of the catalyst prepared by any of the methods according to claims 1-8 or any of the catalysts according to claims 9-11 in the dehydrogenation of 1,4-butanediol to γ-butyrolactone.