A supported Cu catalyst, its preparation method, and a method for preparing methyl ethyl ketone.

Abstract

This invention provides a supported Cu catalyst, its preparation method, and a method for preparing methyl ethyl ketone (MEK). The catalyst has the structural formula Cu-ZnAl-LDO, and the molar ratio of Cu, Zn, and Al in the catalyst is (1-4):(1-3):(1-3). The active centers of the catalyst are Cu nanoparticles rich in surface defects, with a particle size of 3-6 nm. Based on the total mass of the catalyst, the Cu loading of the active centers is 24-30 wt% (based on metal element content). The surface defects are composed of Cu nanoparticles, and the surface defect content is 52-70% based on the surface area of ​​the Cu nanoparticles. This invention achieves a uniform and stable distribution of the active center Cu nanoparticles on the support surface by employing specific material ratios and preparation methods. By controlling the crystal structure and surface electron distribution, it prevents the aggregation and deactivation of nanoparticles during high-temperature and long-term reactions, significantly improving the catalyst's stability and extending its service life.

Description

Technical Field

[0001] This invention relates to the fields of chemical engineering and catalysis, specifically to a supported Cu catalyst, its preparation method, and a method for preparing methyl ethyl ketone. Background Technology

[0002] Methyl ethyl ketone (MEK, also known as 2-butanone) is an excellent organic solvent. Due to its fast drying and stable performance, it is widely used in products such as inks, coatings, adhesives, and lubricant dewaxing. In addition, derivatives of MEK are also widely used in hardeners and anti-skinning agents for paints.

[0003] Currently, the production processes of methyl ethyl ketone (MEK) both domestically and internationally mainly rely on the dehydrogenation reaction of sec-butanol, and Cu-based catalysts are the most important in this reaction, including Cu / ZnO, Cu / ZnOAl2O3, and Cu-ZnO-Cr2O3 / SiO2. Hu et al. prepared Cu / ZnO catalysts using co-precipitation and physical mixing methods, respectively, and found that the catalyst prepared by co-precipitation had better activity. Characterization revealed that Zn could not only disperse Cu species but also prevent Cu sintering under certain conditions (Advanced Materials Research, 2013, 750-752, 1778-1781). However, although co-precipitation can improve the activity of the catalyst, this method is sensitive to preparation conditions, leading to unstable catalyst performance. In addition, Cu / ZnO catalysts can still undergo sintering at high temperatures, affecting their long-term stability and regeneration capacity. Studies have shown that when Cu / ZnOAl2O3 catalysts are used in the dehydrogenation reaction of butanol, a copper-zinc ratio of 30% facilitates copper dispersion by embedding it in the mesoporous framework, thereby reducing the formation of byproducts (Journal of Energy Chemistry, 2009, 18, 179-182). However, although optimizing the copper-zinc ratio helps improve catalytic activity, the selectivity of this catalyst is still limited by the dispersion of copper species and the uniformity of the mesoporous structure. In addition, the regeneration and recycling capabilities of the catalyst also need further improvement. Researchers have found that in the Cu-ZnO-Cr2O3 / SiO2 catalytic system, under high-temperature reduction conditions, while the selectivity of the catalyst for methyl ethyl ketone (MEK) increases, the selectivity of the condensation product decreases. Larger support pore sizes correlate with lower condensation selectivity (Reaction Kinetics & Catalysis Letters, 2002, 76, 271-279). However, while high-temperature reduction conditions can improve selectivity, this may lead to decreased catalyst structural stability, especially during long-term operation. Furthermore, the size of the support pores affects condensation selectivity, requiring precise control of the support material's pore structure, which increases the complexity of the preparation process. On the surface of Cu-based catalysts, Cu particles exhibit significant aggregation behavior at certain temperatures. This aggregation leads to increased particle size, reducing the contact area between active species and reactants, ultimately resulting in decreased catalyst activity. This issue poses a challenge to the long-term stability and reusability of the catalyst.

[0004] In summary, although existing copper-based catalysts have shown certain activity and selectivity in methyl ethyl ketone (MEK) production, they still suffer from technical deficiencies in areas such as stability, regeneration capacity, adaptability, and structural control. Future research should focus on improving the stability of these catalysts, optimizing preparation processes to enhance their industrial application feasibility, and developing new catalytic systems to improve the efficiency and selectivity of MEK production. Summary of the Invention

[0005] To address the problems of existing technologies, this invention provides a supported Cu nanoparticle catalyst. The catalyst exhibits abundant surface defects on the Cu nanoparticles at their catalytic active centers. These surface defects provide more active sites, which facilitate the adsorption and activation of reactants, thereby accelerating the chemical reaction process. The ZnAl-LDO support, as a material with a special layered structure, provides physical isolation between the Cu nanoparticles through its interlayer space, effectively inhibiting direct contact and aggregation between the active Cu nanoparticles. This results in a method for preparing methyl ethyl ketone using the catalyst of this invention, characterized by mild reaction conditions, high catalyst activity, and long service life, making it more suitable for industrial applications.

[0006] This invention provides a supported Cu catalyst, wherein the catalyst uses bimetallic composite hydroxides, also known as layered double hydroxides (LDHs), as precursors, and the divalent cations in the LDH layers are Cu. 2+ and Zn 2+ The trivalent cation is Al 3+ After calcination and reduction, a supported Cu nanoparticle catalyst rich in surface defects was obtained. The support was a layered double oxide (LDO) of zinc and aluminum. The structural formula of the catalyst was Cu-ZnAl-LDO, and the molar ratio of Cu, Zn and Al in the catalyst was (1-4):(1-3):(1-3).

[0007] Furthermore, aberration-corrected electron microscopy revealed that the active centers of the catalyst are Cu nanoparticles rich in surface defects, with a particle size of 3-6 nm. These active centers are uniformly dispersed on a ZnAl-LDO support. ICP testing showed that, based on the total mass of the catalyst, the Cu loading of the active centers was 24-30 wt% (calculated as metal elements). CO adsorption infrared spectroscopy characterization showed that the surface defects were composed of Cu nanoparticles, with a surface defect content of 52-70% based on the surface area of ​​the Cu nanoparticles.

[0008] Furthermore, in the XRD pattern of the catalyst, the characteristic peaks appearing at 31.7°, 34.8°, 36.3°, 47.5°, 56.6°, 62.9°, and 67.9° are the characteristic diffraction peaks of ZnO (100), (002), (101), (102), (110), (103), and (112), respectively. Similarly, the characteristic peak appearing at 43.2° is the (111) crystal plane of Cu, indicating that Cu nanoparticles supported by ZnAl-LDO have been prepared.

[0009] The present invention also provides a method for preparing the aforementioned catalyst, the method comprising the following steps:

[0010] Step 1: Preparation of copper-zinc-aluminum hydrotalcite

[0011] Take 50-100 mmol of Cu(NO3)2∙3H2O, 20-200 mmol of Zn(NO3)2∙6H2O, and 20-200 mmol of Al(NO3)3∙9H2O, and place them in a beaker containing 100-300 mL of deionized water. Stir until completely dissolved to obtain salt solution A. Weigh 20-200 mmol of Na2CO3 and 100-500 mmol of NaOH and place them in a beaker containing 200-500 mL of deionized water. Stir until completely dissolved to obtain alkaline solution B. Place alkaline solution B in a 1000 mL four-necked flask and incubate at room temperature. The mixture is stirred at a speed of 600-1000 r / min. Salt solution A is added dropwise to a four-necked flask at a rate of 1-3 mL / min. After salt solution A is completely added, the final pH value is controlled to be 9-12. The mixture is crystallized at a constant temperature in a water bath at 20-40℃ for 5-24 h. Then, the temperature is increased to 70-90℃ and crystallized at a constant temperature for 5-18 h. Solid sample C is obtained by vacuum filtration. Solid sample C is washed with deionized water until neutral and then dried in an oven at 100-200℃ for 6-12 h. After cooling, it is ground to obtain copper-zinc-aluminum hydrotalcite powder, denoted as CuZnAl-LDHs, which is then dried and stored.

[0012] Step 2: Preparation of supported Cu nanoparticle catalysts

[0013] The CuZnAl-LDHs powder was calcined in air at a temperature of 200-500℃, a heating rate of 1-10℃ / min, and held for 10-60min to obtain calcined sample D. The calcined sample D was then heated to 100-150℃ in an H2 / Ar mixed atmosphere and held for 30-120min. The volume ratio of H2 to Ar in the H2 / Ar mixed atmosphere was (1-3):(7-9). The atmosphere was then switched to pure H2, and the temperature was increased to 180-300℃ and held for 30-120min. Finally, the temperature was increased to 320-550℃ in an N2 atmosphere and held for 40-90min. After cooling to room temperature, the supported Cu nanoparticle catalyst was obtained, denoted as Cu-ZnAl-LDO.

[0014] Furthermore, in step 2, the heating rate under the H2 / Ar mixed atmosphere is 1-50℃ / min.

[0015] Furthermore, in step 2, the heating rate under a pure H2 atmosphere is 1-50℃ / min.

[0016] Furthermore, in step 2, the heating rate under the N2 atmosphere is 1-50℃ / min.

[0017] This invention also provides a method for the efficient preparation of methyl ethyl ketone (MEK), an important chemical raw material, using the aforementioned catalyst for the dehydrogenation of sec-butanol. The method involves weighing the catalyst, granulating it to 20-40 mesh, loading it into a reaction tube, placing the reaction tube into a fixed-bed reactor, and performing a leak test on the apparatus. After the leak test, the catalyst is pre-activated by introducing H2 for pretreatment and maintaining the temperature at 300-600°C for 0.5-3 hours. After cooling to 200-250°C, a reaction feed is introduced to carry out the catalytic reaction. The reaction feed is a mixture of sec-butanol and N2. The sec-butanol enters the reaction apparatus via a liquid path, and the mass hourly space velocity (WHSV) of the sec-butanol is set to 12-15 h⁻¹. -1 N2 enters the reaction apparatus via a gas path, with the N2 flow rate set at 10-100 mL / min and the reaction pressure at 0.1-0.8 MPa. The product of the catalytic reaction is collected in a condenser and then discharged as liquid. The product is quantitatively analyzed using a gas chromatograph, and the conversion rate of sec-butanol is calculated to be 58-90%, and the selectivity of methyl ethyl ketone is above 99%.

[0018] Furthermore, the reaction tube has a diameter of 10 mm and a length of 380 mm.

[0019] Furthermore, the H2 flow rate is 10-100 mL / min.

[0020] Furthermore, the N2 flow rate is 10-100 mL / min.

[0021] The beneficial effects of this invention are as follows:

[0022] 1. The catalyst of the present invention is composed of Cu nanoparticles rich in surface defects and zinc-aluminum layered bimetallic oxide ZnAl-LDO. The surface defects of Cu nanoparticles can provide more active sites, which are conducive to the adsorption and activation of reactants, thereby accelerating the chemical reaction process. Through the lattice confinement effect of the hydrotalcite-based material, these surface defects are effectively stabilized. As a material with a special layered structure, ZnAl-LDO can provide physical isolation between Cu nanoparticles through its interlayer space, effectively inhibiting the direct contact and aggregation between active Cu nanoparticles. In addition, the ordered arrangement of Zn and Al in the lattice structure of ZnAl-LDO can generate a specific local charge distribution, which further affects the surface electronic state of Cu nanoparticles, thereby modulating their catalytic performance and preventing the aggregation and deactivation of nanoparticles at high temperatures or during the reaction process, thus unexpectedly improving the catalytic performance of the catalyst.

[0023] 2. The catalyst of the present invention exhibits unexpected stability. After 16 hours of reaction, the catalyst shows no significant deactivation and the reaction activity can still be maintained at 80%. This stability makes the catalyst more economical and reduces the frequent replacement and related costs required due to catalyst deactivation.

[0024] 3. The preparation process of the Cu nanoparticle catalyst of the present invention is simple, and the copper loading is only 24-30%, which not only reduces the preparation cost of the catalyst, but also helps to reduce the use of metallic Cu, which is of great significance for the effective utilization of resources and environmental protection.

[0025] 4. In the catalytic reaction, the Cu nanoparticle catalyst of the present invention can not only efficiently convert sec-butanol, but also generate methyl ethyl ketone with high selectivity, which can reach 99%. As an important chemical raw material, methyl ethyl ketone is widely used in the production of various products such as pharmaceuticals, coatings, and adhesives. High selectivity means fewer by-products generated, thereby simplifying the product purification process and improving production efficiency and product quality.

[0026] 5. Using the catalyst of this invention, chemical reactions can be carried out under lower temperature and pressure conditions, reducing energy consumption and operational risks. At the same time, due to its high selectivity, the generation of harmful byproducts is reduced, thereby reducing environmental pollution and subsequent treatment costs.

[0027] The catalyst of this invention is not limited to the conversion reaction of sec-butanol. Its unique catalytic performance and stability make it potential for application in other types of organic synthesis reactions, such as hydrogenation, oxidation, and coupling reactions. It is expected to be widely used in chemical, energy, and environmental protection fields.

[0028] In summary, this invention provides a catalyst with excellent performance, good stability, and environmental friendliness. Its innovation lies in optimizing the microenvironment of the catalytic active center through material structural design, thereby achieving highly efficient and selective catalytic conversion. This not only brings new research progress to the field of catalysis science, but also provides strong technical support for green chemical processes in industrial production. Attached Figure Description

[0029] Figure 1 The XRD pattern of the precursor Cu3Zn3Al4-LDHs in Example 1.

[0030] Figure 2 XRD pattern of catalyst 1 Specific Implementation

[0032] The technical solution of the present invention will be described in detail below with reference to specific embodiments of the present invention. The described embodiments are only a part of the present invention, and the present invention is not limited to the embodiments described below.

[0033] Example 1

[0034] Step 1: Preparation of copper-zinc-aluminum hydrotalcite

[0035] Accurately weigh 52 mmol of Cu(NO3)2∙3H2O, 52 mmol of Zn(NO3)2∙6H2O, and 39 mmol of Al(NO3)3∙9H2O, and place them in a beaker containing 200 mL of deionized water. Stir until completely dissolved to obtain salt solution A. Accurately weigh 78 mmol of Na2CO3 and 280 mmol of NaOH, and place them in a beaker containing 400 mL of deionized water. Stir until completely dissolved to obtain alkaline solution B. Place alkaline solution B in a 1000 mL four-necked flask and incubate at room temperature. The mixture was stirred at 600 rpm, and the salt solution A was added dropwise to a four-necked flask at a rate of 1 mL / min. After the salt solution A was completely added, the final pH value was controlled to be 9.5. The mixture was then crystallized at a constant temperature of 30°C for 12 h in a water bath, and then the temperature was increased to 90°C and crystallized at a constant temperature for 12 h. The solid sample C was obtained by vacuum filtration. The solid sample C was washed with deionized water until neutral, and then dried in an oven at 100°C for 12 h. After cooling, it was ground to obtain copper-zinc-aluminum hydrotalcite powder, denoted as Cu3Zn3Al4-LDHs, which was dried and stored.

[0036] Step 2: Preparation of supported Cu nanoparticle catalysts

[0037] 1g of the Cu3Zn3Al4-LDHs was accurately weighed and calcined in air at 300℃ with a heating rate of 1℃ / min for 30min to obtain calcined sample D. The calcined sample D was then heated to 150℃ in an H2 / Ar mixed atmosphere at a heating rate of 1℃ / min and held for 60min. The volume ratio of H2 to Ar in the H2 / Ar mixed atmosphere was 1:9. Then, the atmosphere was switched to pure H2 and the temperature was increased to 300℃ at a heating rate of 20℃ / min and held for 30min. Finally, the temperature was increased to 450℃ in an N2 atmosphere at a heating rate of 10℃ / min and held for 60min. After cooling to room temperature, the supported Cu nanoparticle catalyst 1, denoted as Cu-ZnAl-LDO-1-20-10, was obtained.

[0038] According to ICP analysis, the actual loading of Cu nanoparticles in catalyst 1, based on the total mass of the catalyst and calculated as metal elements, is 30 wt%. CO adsorption infrared spectroscopy characterization shows that there are defect structures on the surface of Cu nanoparticles, and based on the surface area of ​​Cu nanoparticles, the surface defect content is 70%.

[0039] Example 2

[0040] Step 1: Preparation of copper-zinc-aluminum hydrotalcite

[0041] Accurately weigh 52 mmol of Cu(NO3)2∙3H2O, 52 mmol of Zn(NO3)2∙6H2O, and 39 mmol of Al(NO3)3∙9H2O, and place them in a beaker containing 200 mL of deionized water. Stir until completely dissolved to obtain salt solution A. Accurately weigh 78 mmol of Na2CO3 and 280 mmol of NaOH, and place them in a beaker containing 400 mL of deionized water. Stir until completely dissolved to obtain alkaline solution B. Place alkaline solution B in a 1000 mL four-necked flask and incubate at room temperature. The mixture was stirred at 600 rpm, and the salt solution A was added dropwise to a four-necked flask at a rate of 1 mL / min. After the salt solution A was completely added, the final pH value was controlled to be 9.5. The mixture was then crystallized at a constant temperature of 30°C for 12 h in a water bath, and then the temperature was increased to 90°C and crystallized at a constant temperature for 12 h. The solid sample C was obtained by vacuum filtration. The solid sample C was washed with deionized water until neutral, and then dried in an oven at 100°C for 12 h. After cooling, it was ground to obtain copper-zinc-aluminum hydrotalcite powder, denoted as Cu3Zn3Al4-LDHs, which was dried and stored.

[0042] Step 2: Preparation of supported Cu nanoparticle catalysts

[0043] Accurately weigh 1g of the Cu3Zn3Al4-LDHs and calcine it in air at 300℃ with a heating rate of 1℃ / min for 30min to obtain calcined sample D. Then, heat the calcined sample D to 150℃ in an H2 / Ar mixed atmosphere at a heating rate of 10℃ / min and hold for 60min. The volume ratio of H2 to Ar in the H2 / Ar mixed atmosphere is 1:9. Then, switch the atmosphere to pure H2 and heat at 1... o The temperature was increased to 300℃ at a heating rate of C / min, held for 30 min, and finally increased to 450℃ at a heating rate of 10℃ / min under N2 atmosphere, held for 60 min, and cooled to room temperature to obtain supported Cu nanoparticle catalyst 2, denoted as Cu-ZnAl-LDO-10-1-10.

[0044] According to ICP analysis, the actual loading of Cu nanoparticles in catalyst 2, based on the total mass of the catalyst and calculated as metal elements, is 30 wt%. CO adsorption infrared spectroscopy characterization shows that there are defect structures on the surface of Cu nanoparticles, and based on the surface area of ​​Cu nanoparticles, the surface defect content is 65%.

[0045] Example 3

[0046] Step 1: Preparation of copper-zinc-aluminum hydrotalcite

[0047] Accurately weigh 52 mmol of Cu(NO3)2∙3H2O, 52 mmol of Zn(NO3)2∙6H2O, and 39 mmol of Al(NO3)3∙9H2O, and place them in a beaker containing 200 mL of deionized water. Stir until completely dissolved to obtain salt solution A. Accurately weigh 78 mmol of Na2CO3 and 280 mmol of NaOH, and place them in a beaker containing 400 mL of deionized water. Stir until completely dissolved to obtain alkaline solution B. Place alkaline solution B in a 1000 mL four-necked flask and incubate at room temperature. The mixture was stirred at 600 rpm, and the salt solution A was added dropwise to a four-necked flask at a rate of 1 mL / min. After the salt solution A was completely added, the final pH value was controlled to be 9.5. The mixture was then crystallized at a constant temperature of 30°C for 12 h in a water bath, and then the temperature was increased to 90°C and crystallized at a constant temperature for 12 h. The solid sample C was obtained by vacuum filtration. The solid sample C was washed with deionized water until neutral, and then dried in an oven at 100°C for 12 h. After cooling, it was ground to obtain copper-zinc-aluminum hydrotalcite powder, denoted as Cu3Zn3Al4-LDHs, which was dried and stored.

[0048] Step 2: Preparation of supported Cu nanoparticle catalysts

[0049] 1g of the Cu3Zn3Al4-LDHs was accurately weighed and calcined in air at 300℃ with a heating rate of 1℃ / min for 30min to obtain calcined sample D. The calcined sample D was then heated to 150℃ in an H2 / Ar mixed atmosphere at a heating rate of 1℃ / min and held for 60min. The volume ratio of H2 to Ar in the H2 / Ar mixed atmosphere was 1:9. Then, the atmosphere was switched to pure H2 and the temperature was increased to 300℃ at a heating rate of 10℃ / min and held for 30min. Finally, the temperature was increased to 450℃ in an N2 atmosphere at a heating rate of 20℃ / min and held for 60min. After cooling to room temperature, the supported Cu nanoparticle catalyst 3, denoted as Cu-ZnAl-LDO-1-10-20, was obtained.

[0050] According to ICP analysis, the actual loading of Cu nanoparticles in catalyst 3, based on the total mass of the catalyst and calculated as metal elements, is 30 wt%. CO adsorption infrared spectroscopy characterization shows that there are defect structures on the surface of Cu nanoparticles, and based on the surface area of ​​Cu nanoparticles, the surface defect content is 62%.

[0051] Example 4

[0052] Step 1: Preparation of copper-zinc-aluminum hydrotalcite

[0053] Accurately weigh 58.5 mmol of Cu(NO3)2∙3H2O, 39 mmol of Zn(NO3)2∙6H2O, and 39 mmol of Al(NO3)3∙9H2O, and place them in a beaker containing 200 mL of deionized water. Stir until completely dissolved to obtain salt solution A. Accurately weigh 78 mmol of Na2CO3 and 280 mmol of NaOH, and place them in a beaker containing 400 mL of deionized water. Stir until completely dissolved to obtain alkaline solution B. Place alkaline solution B in a 1000 mL container... In a four-necked flask, the mixture was stirred at 600 rpm at room temperature. Salt solution A was added dropwise to the flask at a rate of 1 mL / min. After all salt solution A had been added, the final pH was controlled to be 9.5. The mixture was then crystallized at 30°C in a water bath for 12 hours, followed by a further increase in temperature to 90°C and crystallization for another 12 hours. Solid sample C was obtained by vacuum filtration. Solid sample C was washed with deionized water until neutral, then dried in an oven at 100°C for 12 hours. After cooling, it was ground to obtain copper-zinc-aluminum hydrotalcite powder, denoted as Cu. 1.5 Zn1Al1-LDHs, stored in a dry place;

[0054] Step 2: Preparation of supported Cu nanoparticle catalysts

[0055] Accurately weigh 1g of the Cu 1.5 Zn1Al1-LDHs were calcined in air at 300℃ with a heating rate of 1℃ / min for 30 min to obtain calcined sample D. The calcined sample D was then heated to 150℃ in an H2 / Ar mixed atmosphere at a heating rate of 1℃ / min and held for 60 min. The volume ratio of H2 to Ar in the H2 / Ar mixed atmosphere was 1:9. Then, the atmosphere was switched to pure H2, and the temperature was increased to 300℃ at a heating rate of 20℃ / min and held for 30 min. Finally, the temperature was increased to 450℃ in an N2 atmosphere at a heating rate of 10℃ / min and held for 60 min. After cooling to room temperature, the supported Cu nanoparticle catalyst 4, denoted as Cu-ZnAl-LDO-1-20-10, was obtained.

[0056] According to ICP analysis, the actual loading of Cu nanoparticles in catalyst 4, based on the total mass of the catalyst and calculated as metal elements, is 36 wt%. CO adsorption infrared spectroscopy characterization shows that there are defect structures on the surface of Cu nanoparticles, and based on the surface area of ​​Cu nanoparticles, the surface defect content is 60%.

[0057] Example 5

[0058] Step 1: Preparation of copper-zinc-aluminum hydrotalcite

[0059] Accurately weigh 58.5 mmol of Cu(NO3)2∙3H2O, 39 mmol of Zn(NO3)2∙6H2O, and 39 mmol of Al(NO3)3∙9H2O, and place them in a beaker containing 200 mL of deionized water. Stir until completely dissolved to obtain salt solution A. Accurately weigh 78 mmol of Na2CO3 and 280 mmol of NaOH, and place them in a beaker containing 400 mL of deionized water. Stir until completely dissolved to obtain alkaline solution B. Place alkaline solution B in a 1000 mL container... In a four-necked flask, the mixture was stirred at 600 rpm at room temperature. Salt solution A was added dropwise to the flask at a rate of 1 mL / min. After all salt solution A had been added, the final pH was controlled to be 9.5. The mixture was then crystallized at 30°C in a water bath for 12 hours, followed by a further increase in temperature to 90°C and crystallization for another 12 hours. Solid sample C was obtained by vacuum filtration. Solid sample C was washed with deionized water until neutral, then dried in an oven at 100°C for 12 hours. After cooling, it was ground to obtain copper-zinc-aluminum hydrotalcite powder, denoted as Cu. 1.5 Zn1Al1-LDHs, stored in a dry place;

[0060] Step 2: Preparation of supported Cu nanoparticle catalysts

[0061] Accurately weigh 1g of the Cu 1.5 Zn1Al1-LDHs were calcined in air at 300℃ with a heating rate of 1℃ / min for 30 min to obtain calcined sample D. The calcined sample D was then heated to 150℃ in a mixed H2 / Ar atmosphere at a heating rate of 10℃ / min and held for 60 min. The volume ratio of H2 to Ar in the H2 / Ar mixed atmosphere was 1:9. Then, the atmosphere was switched to pure H2, and the temperature was increased to 300℃ at a heating rate of 1℃ / min and held for 30 min. Finally, the temperature was increased to 450℃ in a N2 atmosphere at a heating rate of 10℃ / min and held for 60 min. After cooling to room temperature, the supported Cu nanoparticle catalyst 5, denoted as Cu-ZnAl-LDHs-10-1-10, was obtained.

[0062] According to ICP analysis, the actual loading of Cu nanoparticles in catalyst 5, based on the total mass of the catalyst and calculated as metal elements, is 36 wt%. CO adsorption infrared spectroscopy characterization shows that there are defect structures on the surface of Cu nanoparticles, and based on the surface area of ​​Cu nanoparticles, the surface defect content is 57%.

[0063] Example 6

[0064] Step 1: Preparation of copper-zinc-aluminum hydrotalcite

[0065] Accurately weigh 58.5 mmol of Cu(NO3)2∙3H2O, 39 mmol of Zn(NO3)2∙6H2O, and 39 mmol of Al(NO3)3∙9H2O, and place them in a beaker containing 200 mL of deionized water. Stir until completely dissolved to obtain salt solution A. Accurately weigh 78 mmol of Na2CO3 and 280 mmol of NaOH, and place them in a beaker containing 400 mL of deionized water. Stir until completely dissolved to obtain alkaline solution B. Place alkaline solution B in a 1000 mL container... In a four-necked flask, the mixture was stirred at 600 rpm at room temperature. Salt solution A was added dropwise to the flask at a rate of 1 mL / min. After all salt solution A had been added, the final pH was controlled to be 9.5. The mixture was then crystallized at 30°C in a water bath for 12 hours, followed by a further increase in temperature to 90°C and crystallization for another 12 hours. Solid sample C was obtained by vacuum filtration. Solid sample C was washed with deionized water until neutral, then dried in an oven at 100°C for 12 hours. After cooling, it was ground to obtain copper-zinc-aluminum hydrotalcite powder, denoted as Cu. 1.5 Zn1Al1-LDHs, stored in a dry place;

[0066] Step 2: Preparation of supported Cu nanoparticle catalysts

[0067] Accurately weigh 1g of the Cu 1.5 Zn1Al1-LDHs were calcined in air at 300℃ with a heating rate of 1℃ / min for 30 min to obtain calcined sample D. The calcined sample D was then heated to 150℃ in a mixed H2 / Ar atmosphere at a heating rate of 1℃ / min and held for 60 min. The volume ratio of H2 to Ar in the H2 / Ar mixed atmosphere was 1:9. Then, the atmosphere was switched to pure H2, and the temperature was increased to 300℃ at a heating rate of 10℃ / min and held for 30 min. Finally, the temperature was increased to 450℃ in a N2 atmosphere at a heating rate of 20℃ / min and held for 60 min. After cooling to room temperature, the supported Cu nanoparticle catalyst 6, denoted as Cu-Zn(Al)O-1-10-20, was obtained.

[0068] According to ICP analysis, the actual loading of Cu nanoparticles in catalyst 6, based on the total mass of the catalyst and calculated as metal elements, is 36 wt%. CO adsorption infrared spectroscopy characterization shows that there are defect structures on the surface of Cu nanoparticles, and based on the surface area of ​​Cu nanoparticles, the surface defect content is 52%.

[0069] Example 7

[0070] Step 1: Preparation of copper-zinc-aluminum hydrotalcite

[0071] Accurately weigh 52 mmol of Cu(NO3)2∙3H2O, 78 mmol of Zn(NO3)2∙6H2O, and 39 mmol of Al(NO3)3∙9H2O, and place them in a beaker containing 200 mL of deionized water. Stir until completely dissolved to obtain salt solution A. Accurately weigh 78 mmol of Na2CO3 and 280 mmol of NaOH, and place them in a beaker containing 400 mL of deionized water. Stir until completely dissolved to obtain alkaline solution B. Place alkaline solution B in a 1000 mL four-necked flask. In a flask, the mixture was stirred at 600 rpm at room temperature. Salt solution A was added dropwise to the four-necked flask at a rate of 1 mL / min. After all salt solution A had been added, the final pH was controlled to 9.5. The mixture was then crystallized at 30°C in a water bath for 12 hours, followed by a further increase in temperature to 90°C and crystallization for another 12 hours. Solid sample C was obtained by vacuum filtration. Solid sample C was washed with deionized water until neutral, then dried in an oven at 100°C for 12 hours. After cooling, it was ground to obtain copper-zinc-aluminum hydrotalcite powder, denoted as Cu1Zn. 1.5 Al1-LDHs, stored in a dry place;

[0072] Step 2: Preparation of supported Cu nanoparticle catalysts

[0073] Accurately weigh 1g of the Cu1Zn 1.5 Al1-LDHs were calcined in air at 300°C with a heating rate of 1°C / min for 30 min to obtain calcined sample D. The calcined sample D was then heated to 150°C in a mixed H2 / Ar atmosphere at a heating rate of 1°C / min and held for 60 min. The volume ratio of H2 to Ar in the H2 / Ar mixed atmosphere was 1:9. Then, the atmosphere was switched to pure H2, and the temperature was increased to 300°C at a heating rate of 20°C / min and held for 30 min. Finally, the temperature was increased to 450°C in a N2 atmosphere at a heating rate of 10°C / min and held for 60 min. After cooling to room temperature, the supported Cu nanoparticle catalyst 7, denoted as CuZnAl-LDO-1-20-10, was obtained.

[0074] According to ICP analysis, the actual loading of Cu nanoparticles in catalyst 7, based on the total mass of the catalyst and the metal element content, is 24 wt%. CO adsorption infrared spectroscopy characterization shows that there are defect structures on the surface of Cu nanoparticles, and the surface defect content is 63% based on the surface area of ​​Cu nanoparticles.

[0075] Example 8

[0076] Step 1: Preparation of copper-zinc-aluminum hydrotalcite

[0077] Accurately weigh 52 mmol of Cu(NO3)2∙3H2O, 78 mmol of Zn(NO3)2∙6H2O, and 39 mmol of Al(NO3)3∙9H2O, and place them in a beaker containing 200 mL of deionized water. Stir until completely dissolved to obtain salt solution A. Accurately weigh 78 mmol of Na2CO3 and 280 mmol of NaOH, and place them in a beaker containing 400 mL of deionized water. Stir until completely dissolved to obtain alkaline solution B. Place alkaline solution B in a 1000 mL four-necked flask. In a flask, the mixture was stirred at 600 rpm at room temperature. Salt solution A was added dropwise to the four-necked flask at a rate of 1 mL / min. After all salt solution A had been added, the final pH was controlled to 9.5. The mixture was then crystallized at 30°C in a water bath for 12 hours, followed by a further increase in temperature to 90°C and crystallization for another 12 hours. Solid sample C was obtained by vacuum filtration. Solid sample C was washed with deionized water until neutral, then dried in an oven at 100°C for 12 hours. After cooling, it was ground to obtain copper-zinc-aluminum hydrotalcite powder, denoted as Cu1Zn. 1.5 Al1-LDHs, stored in a dry place;

[0078] Step 2: Preparation of supported Cu nanoparticle catalysts

[0079] Accurately weigh 1g of the Cu1Zn 1.5 Al1-LDHs were calcined in air at 300°C with a heating rate of 1°C / min for 30 min to obtain calcined sample D. The calcined sample D was then heated to 150°C in a mixed H2 / Ar atmosphere at a heating rate of 10°C / min and held for 60 min. The volume ratio of H2 to Ar in the mixed H2 / Ar atmosphere was 1:9. Then, the atmosphere was switched to pure H2, and the temperature was increased to 300°C at a heating rate of 1°C / min and held for 30 min. Finally, the temperature was increased to 450°C in a N2 atmosphere at a heating rate of 10°C / min and held for 60 min. After cooling to room temperature, the supported Cu nanoparticle catalyst 8, denoted as CuZnAl-LDO-10-1-10, was obtained.

[0080] According to ICP analysis, the actual loading of Cu nanoparticles in catalyst 8, based on the total mass of the catalyst and calculated as metal elements, is 24 wt%. CO adsorption infrared spectroscopy characterization shows that there are defect structures on the surface of Cu nanoparticles, and based on the surface area of ​​Cu nanoparticles, the surface defect content is 58%.

[0081] Example 9

[0082] Step 1: Preparation of copper-zinc-aluminum hydrotalcite

[0083] Accurately weigh 52 mmol of Cu(NO3)2∙3H2O, 78 mmol of Zn(NO3)2∙6H2O, and 39 mmol of Al(NO3)3∙9H2O, and place them in a beaker containing 200 mL of deionized water. Stir until completely dissolved to obtain salt solution A. Accurately weigh 78 mmol of Na2CO3 and 280 mmol of NaOH, and place them in a beaker containing 400 mL of deionized water. Stir until completely dissolved to obtain alkaline solution B. Place alkaline solution B in a 1000 mL four-necked flask. In a flask, the mixture was stirred at 600 rpm at room temperature. Salt solution A was added dropwise to the four-necked flask at a rate of 1 mL / min. After all salt solution A had been added, the final pH was controlled to 9.5. The mixture was then crystallized at 30°C in a water bath for 12 hours, followed by a further increase in temperature to 90°C and crystallization for another 12 hours. Solid sample C was obtained by vacuum filtration. Solid sample C was washed with deionized water until neutral, then dried in an oven at 100°C for 12 hours. After cooling, it was ground to obtain copper-zinc-aluminum hydrotalcite powder, denoted as Cu1Zn. 1.5 Al1-LDHs, stored in a dry place;

[0084] Step 2: Preparation of supported Cu nanoparticle catalysts

[0085] Accurately weigh 1g of the Cu1Zn 1.5 Al1-LDHs were calcined in air at 300°C with a heating rate of 1°C / min for 30 min to obtain calcined sample D. The calcined sample D was then heated to 150°C in a mixed H2 / Ar atmosphere at a heating rate of 1°C / min for 60 min. The volume ratio of H2 to Ar in the H2 / Ar mixed atmosphere was 1:9. Then, the atmosphere was switched to pure H2, and the temperature was increased to 300°C at a heating rate of 10°C / min for 30 min. Finally, the temperature was increased to 450°C in a N2 atmosphere at a heating rate of 20°C / min for 60 min. After cooling to room temperature, the supported Cu nanoparticle catalyst 9, denoted as CuZnAl-LDHs-1-10-20, was obtained.

[0086] According to ICP analysis, the actual loading of Cu nanoparticles in catalyst 9, based on the total mass of the catalyst and calculated as metal elements, is 24 wt%. CO adsorption infrared spectroscopy characterization shows that there are defect structures on the surface of Cu nanoparticles, and based on the surface area of ​​Cu nanoparticles, the surface defect content is 54%.

[0087] Comparative Example 1

[0088] Step 1: Preparation of copper-zinc-aluminum hydrotalcite

[0089] Accurately weigh 52 mmol of Cu(NO3)2∙3H2O, 52 mmol of Zn(NO3)2∙6H2O, and 39 mmol of Al(NO3)3∙9H2O, and place them in a beaker containing 200 mL of deionized water. Stir until completely dissolved to obtain salt solution A. Accurately weigh 78 mmol of Na2CO3 and 280 mmol of NaOH, and place them in a beaker containing 400 mL of deionized water. Stir until completely dissolved to obtain alkaline solution B. Place alkaline solution B in a 1000 mL four-necked flask and incubate at room temperature. The mixture was stirred at 600 rpm, and the salt solution A was added dropwise to a four-necked flask at a rate of 1 mL / min. After the salt solution A was completely added, the final pH value was controlled to be 9.5. The mixture was then crystallized at a constant temperature of 30°C for 12 h in a water bath, and then the temperature was increased to 90°C and crystallized at a constant temperature for 12 h. The solid sample C was obtained by vacuum filtration. The solid sample C was washed with deionized water until neutral, and then dried in an oven at 100°C for 12 h. After cooling, it was ground to obtain copper-zinc-aluminum hydrotalcite powder, denoted as Cu3Zn3Al4-LDHs, which was dried and stored.

[0090] Step 2: Preparation of supported Cu nanoparticle catalysts

[0091] 1g of the Cu3Zn3Al4-LDHs was accurately weighed and calcined in air at 300℃ with a heating rate of 1℃ / min for 30min to obtain calcined sample D. The calcined sample D was then heated to 450℃ in an H2 / Ar mixed atmosphere at a heating rate of 1℃ / min for 60min. The volume ratio of H2 to Ar in the H2 / Ar mixed atmosphere was 1:9. After cooling, the supported Cu nanoparticle catalyst 10 was obtained, denoted as Cu-ZnAl-LDO-1.

[0092] According to ICP analysis, the actual loading of Cu nanoparticles in catalyst 10, based on the total mass of the catalyst and calculated as metal elements, is 30 wt%. CO adsorption infrared spectroscopy characterization shows that there are defect structures on the surface of Cu nanoparticles, and based on the surface area of ​​Cu nanoparticles, the surface defect content is 18%.

[0093] Comparative Example 2

[0094] Step 1: Preparation of copper-zinc-aluminum hydrotalcite

[0095] Accurately weigh 52 mmol of Cu(NO3)2∙3H2O, 52 mmol of Zn(NO3)2∙6H2O, and 39 mmol of Al(NO3)3∙9H2O, and place them in a beaker containing 200 mL of deionized water. Stir until completely dissolved to obtain salt solution A. Accurately weigh 78 mmol of Na2CO3 and 280 mmol of NaOH, and place them in a beaker containing 400 mL of deionized water. Stir until completely dissolved to obtain alkaline solution B. Place alkaline solution B in a 1000 mL four-necked flask and incubate at room temperature. The mixture was stirred at 600 rpm, and the salt solution A was added dropwise to a four-necked flask at a rate of 1 mL / min. After the salt solution A was completely added, the final pH value was controlled to be 9.5. The mixture was then crystallized at a constant temperature of 30°C for 12 h in a water bath, and then the temperature was increased to 90°C and crystallized at a constant temperature for 12 h. The solid sample C was obtained by vacuum filtration. The solid sample C was washed with deionized water until neutral, and then dried in an oven at 100°C for 12 h. After cooling, it was ground to obtain copper-zinc-aluminum hydrotalcite powder, denoted as Cu3Zn3Al4-LDHs, which was dried and stored.

[0096] Step 2: Preparation of supported Cu nanoparticle catalysts

[0097] 1g of the Cu3Zn3Al4-LDHs was accurately weighed and calcined in air at 300℃ with a heating rate of 1℃ / min for 30min to obtain calcined sample D. The calcined sample D was then heated to 450℃ in H2 atmosphere at a heating rate of 10℃ / min for 60min. After cooling, the supported Cu nanoparticle catalyst 11 was obtained, denoted as Cu-ZnAl-LDO-10.

[0098] According to ICP analysis, the actual loading of Cu nanoparticles in catalyst 11 is 30 wt% based on the total mass of the catalyst and the metal element content. CO adsorption infrared spectroscopy characterization shows that there are defect structures on the surface of Cu nanoparticles, and the surface defect content is 16% based on the surface area of ​​Cu nanoparticles.

[0099] Comparative Example 3

[0100] Step 1: Preparation of copper-zinc-aluminum hydrotalcite

[0101] Accurately weigh 52 mmol of Cu(NO3)2∙3H2O, 52 mmol of Zn(NO3)2∙6H2O, and 39 mmol of Al(NO3)3∙9H2O, and place them in a beaker containing 200 mL of deionized water. Stir until completely dissolved to obtain salt solution A. Accurately weigh 78 mmol of Na2CO3 and 280 mmol of NaOH, and place them in a beaker containing 400 mL of deionized water. Stir until completely dissolved to obtain alkaline solution B. Place alkaline solution B in a 1000 mL four-necked flask and incubate at room temperature. The mixture was stirred at 600 rpm, and the salt solution A was added dropwise to a four-necked flask at a rate of 1 mL / min. After the salt solution A was completely added, the final pH value was controlled to be 9.5. The mixture was then crystallized at a constant temperature of 30°C for 12 h in a water bath, and then the temperature was increased to 90°C and crystallized at a constant temperature for 12 h. The solid sample C was obtained by vacuum filtration. The solid sample C was washed with deionized water until neutral, and then dried in an oven at 100°C for 4 h. After cooling, it was ground to obtain copper-zinc-aluminum hydrotalcite powder, denoted as Cu3Zn3Al4-LDHs, which was dried and stored.

[0102] Step 2: Preparation of supported Cu nanoparticle catalysts

[0103] 1g of the Cu3Zn3Al4-LDHs was accurately weighed and calcined in air at 300℃ with a heating rate of 1℃ / min for 30 min to obtain calcined sample D. The calcined sample D was then heated to 450℃ in H2 atmosphere at a heating rate of 20℃ / min and held for 60 min. After cooling, the supported Cu nanoparticle catalyst 12 was obtained, denoted as Cu-ZnAl-LDO-20.

[0104] According to ICP analysis, the actual loading of Cu nanoparticles in catalyst 12, based on the total mass of the catalyst and calculated as metal elements, is 30 wt%. CO adsorption infrared spectroscopy characterization shows that there are defect structures on the surface of Cu nanoparticles, and based on the surface area of ​​Cu nanoparticles, the surface defect content is 10%.

[0105] Comparative Example 4

[0106] Step 1: Preparation of copper-zinc-aluminum hydrotalcite

[0107] Accurately weigh 58.5 mmol of Cu(NO3)2∙3H2O, 39 mmol of Zn(NO3)2∙6H2O, and 39 mmol of Al(NO3)3∙9H2O, and place them in a beaker containing 200 mL of deionized water. Stir until completely dissolved to obtain salt solution A. Accurately weigh 78 mmol of Na2CO3 and 280 mmol of NaOH, and place them in a beaker containing 400 mL of deionized water. Stir until completely dissolved to obtain alkaline solution B. Place alkaline solution B in a 1000 mL container... In a four-necked flask, the mixture was stirred at 600 rpm at room temperature. Salt solution A was added dropwise to the flask at a rate of 1 mL / min. After all salt solution A had been added, the final pH was controlled to be 9.5. The mixture was then crystallized at 30°C in a water bath for 12 hours, followed by a further increase in temperature to 90°C and crystallization for another 12 hours. Solid sample C was obtained by vacuum filtration. Solid sample C was washed with deionized water until neutral, then dried in an oven at 100°C for 4 hours. After cooling, it was ground to obtain copper-zinc-aluminum hydrotalcite powder, denoted as Cu. 1.5 Zn1Al1-LDHs, stored in a dry place;

[0108] Step 2: Preparation of supported Cu nanoparticle catalysts

[0109] Accurately weigh 1g of the Cu 1.5 Zn1Al1-LDHs were calcined in air at 300℃ with a heating rate of 1℃ / min for 30 min to obtain calcined sample D. The calcined sample D was then heated to 450℃ in H2 atmosphere at a heating rate of 1℃ / min for 60 min. After cooling, supported Cu nanoparticle catalyst 13 was obtained, denoted as Cu-ZnAl-LDO-1.

[0110] According to ICP analysis, the actual loading of Cu nanoparticles in catalyst 13, based on the total mass of the catalyst and calculated as metal elements, is 36 wt%. CO adsorption infrared spectroscopy characterization shows that there are defect structures on the surface of Cu nanoparticles, and based on the surface area of ​​Cu nanoparticles, the surface defect content is 14%.

[0111] Comparative Example 5

[0112] Step 1: Preparation of copper-zinc-aluminum hydrotalcite

[0113] Accurately weigh 58.5 mmol of Cu(NO3)2∙3H2O, 39 mmol of Zn(NO3)2∙6H2O, and 39 mmol of Al(NO3)3∙9H2O, and place them in a beaker containing 200 mL of deionized water. Stir until completely dissolved to obtain salt solution A. Accurately weigh 78 mmol of Na2CO3 and 280 mmol of NaOH, and place them in a beaker containing 400 mL of deionized water. Stir until completely dissolved to obtain alkaline solution B. Place alkaline solution B in a 1000 mL container... In a four-necked flask, the mixture was stirred at 600 rpm at room temperature. Salt solution A was added dropwise to the flask at a rate of 1 mL / min. After all salt solution A had been added, the final pH was controlled to be 9.5. The mixture was then crystallized at 30°C in a water bath for 12 hours, followed by a further increase in temperature to 90°C and crystallization for another 12 hours. Solid sample C was obtained by vacuum filtration. Solid sample C was washed with deionized water until neutral, then dried in an oven at 100°C for 4 hours. After cooling, it was ground to obtain copper-zinc-aluminum hydrotalcite powder, denoted as Cu. 1.5 Zn1Al1-LDHs, stored in a dry place;

[0114] Step 2: Preparation of supported Cu nanoparticle catalysts

[0115] Accurately weigh 1g of the Cu 1.5 Zn1Al1-LDHs were calcined in air at 300℃ with a heating rate of 1℃ / min for 30 min to obtain calcined sample D. The calcined sample D was then heated to 450℃ in H2 atmosphere at a heating rate of 10℃ / min for 60 min. After cooling, supported Cu nanoparticle catalyst 14, denoted as Cu-ZnAl-LDO-10, was obtained.

[0116] According to ICP analysis, the actual loading of Cu nanoparticles in catalyst 14, based on the total mass of the catalyst and calculated as metal elements, is 36 wt%. CO adsorption infrared spectroscopy characterization shows that there are defect structures on the surface of Cu nanoparticles, and based on the surface area of ​​Cu nanoparticles, the surface defect content is 12%.

[0117] Comparative Example 6

[0118] Step 1: Preparation of copper-zinc-aluminum hydrotalcite

[0119] Accurately weigh 58.5 mmol of Cu(NO3)2∙3H2O, 39 mmol of Zn(NO3)2∙6H2O, and 39 mmol of Al(NO3)3∙9H2O, and place them in a beaker containing 200 mL of deionized water. Stir until completely dissolved to obtain salt solution A. Accurately weigh 78 mmol of Na2CO3 and 280 mmol of NaOH, and place them in a beaker containing 400 mL of deionized water. Stir until completely dissolved to obtain alkaline solution B. Place alkaline solution B in a 1000 mL container... In a four-necked flask, the mixture was stirred at 600 rpm at room temperature. Salt solution A was added dropwise to the flask at a rate of 1 mL / min. After all salt solution A had been added, the final pH was controlled to be 9.5. The mixture was then crystallized at 30°C in a water bath for 12 hours, followed by a further increase in temperature to 90°C and crystallization for another 12 hours. Solid sample C was obtained by vacuum filtration. Solid sample C was washed with deionized water until neutral, then dried in an oven at 100°C for 4 hours. After cooling, it was ground to obtain copper-zinc-aluminum hydrotalcite powder, denoted as Cu. 1.5 Zn1Al1-LDHs, stored in a dry place;

[0120] Step 2: Preparation of supported Cu nanoparticle catalysts

[0121] Accurately weigh 1g of the Cu 1.5 Zn1Al1-LDHs were calcined in air at 300℃ with a heating rate of 1℃ / min for 30 min to obtain calcined sample D. The calcined sample D was then heated to 450℃ in H2 atmosphere at a heating rate of 20℃ / min for 60 min. After cooling, supported Cu nanoparticle catalyst 15 was obtained, denoted as Cu-ZnAl-LDO-20.

[0122] According to ICP analysis, the actual loading of Cu nanoparticles in catalyst 15, based on the total mass of the catalyst and calculated as metal elements, is 36 wt%. CO adsorption infrared spectroscopy characterization shows that there are defect structures on the surface of Cu nanoparticles, and based on the surface area of ​​Cu nanoparticles, the surface defect content is 6%.

[0123] Comparative Example 7

[0124] Step 1: Preparation of copper-zinc-aluminum hydrotalcite

[0125] Accurately weigh 52 mmol of Cu(NO3)2∙3H2O, 78 mmol of Zn(NO3)2∙6H2O, and 39 mmol of Al(NO3)3∙9H2O, and place them in a beaker containing 200 mL of deionized water. Stir until completely dissolved to obtain salt solution A. Accurately weigh 78 mmol of Na2CO3 and 280 mmol of NaOH, and place them in a beaker containing 400 mL of deionized water. Stir until completely dissolved to obtain alkaline solution B. Place alkaline solution B in a 1000 mL four-necked flask. In a flask, the mixture was stirred at 600 rpm at room temperature. Salt solution A was added dropwise to the four-necked flask at a rate of 1 mL / min. After all salt solution A had been added, the final pH was controlled to 9.5. The mixture was then crystallized at 30°C in a water bath for 12 hours, followed by a further increase in temperature to 90°C and crystallization for another 12 hours. Solid sample C was obtained by vacuum filtration. Solid sample C was washed with deionized water until neutral, then dried in an oven at 100°C for 4 hours. After cooling, it was ground to obtain copper-zinc-aluminum hydrotalcite powder, denoted as Cu1Zn. 1.5 Al1-LDHs, stored in a dry place;

[0126] Step 2: Preparation of supported Cu nanoparticle catalysts

[0127] Accurately weigh 1g of the Cu1Zn 1.5 Al1-LDHs were calcined in air at 300°C with a heating rate of 1°C / min for 30 min to obtain calcined sample D. The calcined sample D was then heated to 450°C in H2 atmosphere at a heating rate of 1°C / min for 60 min. After cooling, supported Cu nanoparticle catalyst 16, denoted as Cu-ZnAl-LDO-1, was obtained.

[0128] According to ICP analysis, the actual loading of Cu nanoparticles in catalyst 16, based on the total mass of the catalyst and calculated as metal elements, is 24 wt%. CO adsorption infrared spectroscopy characterization shows that there are defect structures on the surface of Cu nanoparticles, and based on the surface area of ​​Cu nanoparticles, the surface defect content is 17%.

[0129] Comparative Example 8

[0130] Step 1: Preparation of copper-zinc-aluminum hydrotalcite

[0131] Accurately weigh 52 mmol of Cu(NO3)2∙3H2O, 78 mmol of Zn(NO3)2∙6H2O, and 39 mmol of Al(NO3)3∙9H2O, and place them in a beaker containing 200 mL of deionized water. Stir until completely dissolved to obtain salt solution A. Accurately weigh 78 mmol of Na2CO3 and 280 mmol of NaOH, and place them in a beaker containing 400 mL of deionized water. Stir until completely dissolved to obtain alkaline solution B. Place alkaline solution B in a 1000 mL four-necked flask. In a flask, the mixture was stirred at 600 rpm at room temperature. Salt solution A was added dropwise to the four-necked flask at a rate of 1 mL / min. After all salt solution A had been added, the final pH was controlled to 9.5. The mixture was then crystallized at 30°C in a water bath for 12 hours, followed by a further increase in temperature to 90°C and crystallization for another 12 hours. Solid sample C was obtained by vacuum filtration. Solid sample C was washed with deionized water until neutral, then dried in an oven at 100°C for 4 hours. After cooling, it was ground to obtain copper-zinc-aluminum hydrotalcite powder, denoted as Cu1Zn. 1.5 Al1-LDHs, stored in a dry place;

[0132] Step 2: Preparation of supported Cu nanoparticle catalysts

[0133] Accurately weigh 1g of the Cu1Zn 1.5 Al1-LDHs were calcined in air at 300°C with a heating rate of 1°C / min for 30 min to obtain calcined sample D. The calcined sample D was then heated to 450°C in H2 atmosphere at a heating rate of 10°C / min for 60 min. After cooling, supported Cu nanoparticle catalyst 17, denoted as Cu-ZnAl-LDO-10, was obtained.

[0134] According to ICP analysis, the actual loading of Cu nanoparticles in catalyst 17, based on the total mass of the catalyst and calculated as metal elements, is 24 wt%. CO adsorption infrared spectroscopy characterization shows that there are defect structures on the surface of Cu nanoparticles, and based on the surface area of ​​Cu nanoparticles, the surface defect content is 15%.

[0135] Comparative Example 9

[0136] Step 1: Preparation of copper-zinc-aluminum hydrotalcite

[0137] Accurately weigh 52 mmol of Cu(NO3)2∙3H2O, 78 mmol of Zn(NO3)2∙6H2O, and 39 mmol of Al(NO3)3∙9H2O, and place them in a beaker containing 200 mL of deionized water. Stir until completely dissolved to obtain salt solution A. Accurately weigh 78 mmol of Na2CO3 and 280 mmol of NaOH, and place them in a beaker containing 400 mL of deionized water. Stir until completely dissolved to obtain alkaline solution B. Place alkaline solution B in a 1000 mL four-necked flask. In a flask, the mixture was stirred at 600 rpm at room temperature. Salt solution A was added dropwise to the four-necked flask at a rate of 1 mL / min. After all salt solution A had been added, the final pH was controlled to 9.5. The mixture was then crystallized at 30°C in a water bath for 12 hours, followed by a further increase in temperature to 90°C and crystallization for another 12 hours. Solid sample C was obtained by vacuum filtration. Solid sample C was washed with deionized water until neutral, then dried in an oven at 100°C for 4 hours. After cooling, it was ground to obtain copper-zinc-aluminum hydrotalcite powder, denoted as Cu1Zn. 1.5 Al1-LDHs, stored in a dry place;

[0138] Step 2: Preparation of supported Cu nanoparticle catalysts

[0139] Accurately weigh 1g of the Cu1Zn 1.5 Al1-LDHs were calcined in air at 300°C with a heating rate of 1°C / min for 30 min to obtain calcined sample D. The calcined sample D was then heated to 450°C in H2 atmosphere at a heating rate of 20°C / min for 60 min. After cooling, supported Cu nanoparticle catalyst 18 was obtained, denoted as Cu-ZnAl-LDO-20.

[0140] According to ICP analysis, the actual loading of Cu nanoparticles in catalyst 18, based on the total mass of the catalyst and calculated as metal elements, is 24 wt%. CO adsorption infrared spectroscopy characterization shows that there are defect structures on the surface of Cu nanoparticles, and based on the surface area of ​​Cu nanoparticles, the surface defect content is 8%.

[0141] Comparative Example 10

[0142] Step 1: Preparation of zinc-aluminum hydrotalcite

[0143] Accurately weigh 117 mmol of Zn(NO3)2∙6H2O and 39 mmol of Al(NO3)3∙9H2O, and place them in a beaker containing 200 mL of deionized water. Stir until completely dissolved to obtain salt solution A. Accurately weigh 78 mmol of Na2CO3 and 280 mmol of NaOH, and place them in a beaker containing 400 mL of deionized water. Stir until completely dissolved to obtain alkaline solution B. Place alkaline solution B in a 1000 mL four-necked flask and stir at room temperature at a speed of [missing value]. At a speed of 600 r / min, the salt solution A was added dropwise to a four-necked flask at a rate of 1 mL / min. After the salt solution A was completely added, the final pH value was controlled to be 9.5. After crystallization at a constant temperature of 30℃ in a water bath for 12 h, the temperature was increased to 90℃ and crystallized at a constant temperature for 12 h. Solid sample C was obtained by vacuum filtration. Solid sample C was washed with deionized water until neutral, and then dried in an oven at 100℃ for 4 h. After cooling, it was ground to obtain zinc aluminum hydrotalcite powder, denoted as Zn3Al1-LDHs, and stored after drying.

[0144] Step 2: Preparation of metal oxide catalysts

[0145] 1g of the Zn3Al1-LDHs was accurately weighed and calcined in air at 300℃ with a heating rate of 1℃ / min for 30min to obtain calcined sample D. The calcined sample D was then heated to 150℃ in an H2 / Ar mixed atmosphere at a heating rate of 1℃ / min and held for 60min. The volume ratio of H2 to Ar in the H2 / Ar mixed atmosphere was 1:9. Then, the atmosphere was switched to pure H2 and the temperature was increased to 300℃ at a heating rate of 20℃ / min and held for 30min. Finally, the temperature was increased to 450℃ in an N2 atmosphere at a heating rate of 10℃ / min and held for 60min. After cooling, metal oxide catalyst 19 was obtained, denoted as ZnAl-LDO-1-20-10.

[0146] Comparative Example 11

[0147] Step 1: Preparation of zinc-aluminum hydrotalcite

[0148] Accurately weigh 117 mmol of Zn(NO3)2∙6H2O and 39 mmol of Al(NO3)3∙9H2O, and place them in a beaker containing 200 mL of deionized water. Stir until completely dissolved to obtain salt solution A. Accurately weigh 78 mmol of Na2CO3 and 280 mmol of NaOH, and place them in a beaker containing 400 mL of deionized water. Stir until completely dissolved to obtain alkaline solution B. Place alkaline solution B in a 1000 mL four-necked flask and stir at room temperature at a speed of [missing value]. At a speed of 600 r / min, the salt solution A was added dropwise to a four-necked flask at a rate of 1 mL / min. After the salt solution A was completely added, the final pH value was controlled to be 9.5. After crystallization at a constant temperature of 30℃ in a water bath for 12 h, the temperature was increased to 90℃ and crystallized at a constant temperature for 12 h. Solid sample C was obtained by vacuum filtration. Solid sample C was washed with deionized water until neutral, and then dried in an oven at 100℃ for 4 h. After cooling, it was ground to obtain zinc aluminum hydrotalcite powder, denoted as Zn3Al1-LDHs, and stored after drying.

[0149] Step 2: Preparation of metal oxide catalysts

[0150] 1g of the Zn3Al1-LDHs was accurately weighed and calcined in air at 300℃ with a heating rate of 1℃ / min for 30min to obtain calcined sample D. The calcined sample D was then heated to 150℃ in a H2 / Ar mixed atmosphere at a heating rate of 10℃ / min and held for 60min. The volume ratio of H2 to Ar in the H2 / Ar mixed atmosphere was 1:9. Then, the atmosphere was switched to pure H2 and the temperature was increased to 300℃ at a heating rate of 1℃ / min for 30min. Finally, the temperature was increased to 450℃ in a N2 atmosphere at a heating rate of 10℃ / min and held for 60min. After cooling, metal oxide catalyst 20 was obtained, denoted as ZnAl-LDO-10-1-10.

[0151] Comparative Example 12

[0152] Step 1: Preparation of zinc-aluminum hydrotalcite

[0153] Accurately weigh 117 mmol of Zn(NO3)2∙6H2O and 39 mmol of Al(NO3)3∙9H2O, and place them in a beaker containing 200 mL of deionized water. Stir until completely dissolved to obtain salt solution A. Accurately weigh 78 mmol of Na2CO3 and 280 mmol of NaOH, and place them in a beaker containing 400 mL of deionized water. Stir until completely dissolved to obtain alkaline solution B. Place alkaline solution B in a 1000 mL four-necked flask and stir at room temperature at a speed of [missing value]. At a speed of 600 r / min, the salt solution A was added dropwise to a four-necked flask at a rate of 1 mL / min. After the salt solution A was completely added, the final pH value was controlled to be 9.5. After crystallization at a constant temperature of 30℃ in a water bath for 12 h, the temperature was increased to 90℃ and crystallized at a constant temperature for 12 h. Solid sample C was obtained by vacuum filtration. Solid sample C was washed with deionized water until neutral, and then dried in an oven at 100℃ for 4 h. After cooling, it was ground to obtain zinc aluminum hydrotalcite powder, denoted as Zn3Al1-LDHs, and stored after drying.

[0154] Step 2: Preparation of metal oxide catalysts

[0155] 1g of the Zn3Al1-LDHs was accurately weighed and calcined in air at 300℃ with a heating rate of 1℃ / min for 30min to obtain calcined sample D. The calcined sample D was then heated to 150℃ in an H2 / Ar mixed atmosphere at a heating rate of 1℃ / min and held for 60min. The volume ratio of H2 to Ar in the H2 / Ar mixed atmosphere was 1:9. Then, the atmosphere was switched to pure H2 and the temperature was increased to 300℃ at a heating rate of 10℃ / min and held for 30min. Finally, the temperature was increased to 450℃ in an N2 atmosphere at a heating rate of 20℃ / min and held for 60min. After cooling, metal oxide catalyst 21 was obtained, denoted as ZnAl-LDO-1-10-20.

[0156] Comparative Example 13

[0157] Step 1: Preparation of zinc-aluminum hydrotalcite

[0158] Accurately weigh 117 mmol of Zn(NO3)2∙6H2O and 39 mmol of Al(NO3)3∙9H2O, and place them in a beaker containing 200 mL of deionized water. Stir until completely dissolved to obtain salt solution A. Accurately weigh 78 mmol of Na2CO3 and 280 mmol of NaOH, and place them in a beaker containing 400 mL of deionized water. Stir until completely dissolved to obtain alkaline solution B. Place alkaline solution B in a 1000 mL four-necked flask and stir at room temperature at a speed of [missing value]. At a speed of 600 r / min, the salt solution A was added dropwise to a four-necked flask at a rate of 1 mL / min. After the salt solution A was completely added, the final pH value was controlled to be 9.5. After crystallization at a constant temperature of 30℃ in a water bath for 12 h, the temperature was increased to 90℃ and crystallized at a constant temperature for 12 h. Solid sample C was obtained by vacuum filtration. Solid sample C was washed with deionized water until neutral, and then dried in an oven at 100℃ for 4 h. After cooling, it was ground to obtain zinc aluminum hydrotalcite powder, denoted as Zn3Al1-LDHs, and stored after drying.

[0159] Step 2: Preparation of metal oxide catalysts

[0160] 1g of the Zn3Al1-LDHs was accurately weighed and calcined in air at 300℃ with a heating rate of 1℃ / min for 30min to obtain calcined sample D. The calcined sample D was then heated to 450℃ in an H2 / Ar mixed atmosphere at a heating rate of 1℃ / min for 60min. The volume ratio of H2 to Ar in the H2 / Ar mixed atmosphere was 1:9. After cooling, metal oxide catalyst 22 was obtained, denoted as ZnAl-LDO-1.

[0161] Comparative Example 14

[0162] Step 1: Preparation of zinc-aluminum hydrotalcite

[0163] Accurately weigh 117 mmol of Zn(NO3)2∙6H2O and 39 mmol of Al(NO3)3∙9H2O, and place them in a beaker containing 200 mL of deionized water. Stir until completely dissolved to obtain salt solution A. Accurately weigh 78 mmol of Na2CO3 and 280 mmol of NaOH, and place them in a beaker containing 400 mL of deionized water. Stir until completely dissolved to obtain alkaline solution B. Place alkaline solution B in a 1000 mL four-necked flask and stir at room temperature at a speed of [missing value]. At a speed of 600 r / min, the salt solution A was added dropwise to a four-necked flask at a rate of 1 mL / min. After the salt solution A was completely added, the final pH value was controlled to be 9.5. After crystallization at a constant temperature of 30℃ in a water bath for 12 h, the temperature was increased to 90℃ and crystallized at a constant temperature for 12 h. Solid sample C was obtained by vacuum filtration. Solid sample C was washed with deionized water until neutral, and then dried in an oven at 100℃ for 4 h. After cooling and grinding, zinc aluminum hydrotalcite powder was obtained, denoted as Zn3Al1-LDHs, and stored after drying.

[0164] Step 2: Preparation of metal oxide catalysts

[0165] 1g of the Zn3Al1-LDHs was accurately weighed and calcined in air at 300℃ with a heating rate of 1℃ / min for 30min to obtain calcined sample D. The calcined sample D was then heated to 450℃ in an H2 / Ar mixed atmosphere at a heating rate of 10℃ / min for 60min. The volume ratio of H2 to Ar in the H2 / Ar mixed atmosphere was 1:9. After cooling, metal oxide catalyst 23 was obtained, denoted as ZnAl-LDO-10.

[0166] Comparative Example 15

[0167] Step 1: Preparation of zinc-aluminum hydrotalcite

[0168] Accurately weigh 117 mmol of Zn(NO3)2∙6H2O and 39 mmol of Al(NO3)3∙9H2O, and place them in a beaker containing 200 mL of deionized water. Stir until completely dissolved to obtain salt solution A. Accurately weigh 78 mmol of Na2CO3 and 280 mmol of NaOH, and place them in a beaker containing 400 mL of deionized water. Stir until completely dissolved to obtain alkaline solution B. Place alkaline solution B in a 1000 mL four-necked flask and stir at room temperature at a speed of [missing value]. At a speed of 600 r / min, the salt solution A was added dropwise to a four-necked flask at a rate of 1 mL / min. After the salt solution A was completely added, the final pH value was controlled to be 9.5. After crystallization at a constant temperature of 30℃ in a water bath for 12 h, the temperature was increased to 90℃ and crystallized at a constant temperature for 12 h. Solid sample C was obtained by vacuum filtration. Solid sample C was washed with deionized water until neutral, and then dried in an oven at 100℃ for 4 h. After cooling and grinding, zinc aluminum hydrotalcite powder was obtained, denoted as Zn3Al1-LDHs, and stored after drying.

[0169] Step 2: Preparation of metal oxide catalysts

[0170] 1g of the Zn3Al1-LDHs was accurately weighed and calcined in air at 300℃ with a heating rate of 1℃ / min for 30min to obtain calcined sample D. The calcined sample D was then heated to 450℃ in an H2 / Ar mixed atmosphere at a heating rate of 20℃ / min for 60min. The volume ratio of H2 to Ar in the H2 / Ar mixed atmosphere was 1:9. After cooling, oxide catalyst 24 was obtained, denoted as ZnAl-LDO-20.

[0171] Accurately weigh 0.5g each of the aforementioned catalysts 1-24, compress them into tablets, and granulate them into granular catalysts using a 40-mesh granulation process for catalytic reaction. The granular catalysts are then loaded into reaction tubes with a diameter of 10mm and a length of 380mm. These reaction tubes are then placed in a fixed-bed reactor. The apparatus is leak-tested. After leak testing, the catalysts are pre-activated by introducing H2 at a flow rate of 30mL / min and maintaining the temperature at 300℃ for 0.5h. After cooling to 220℃, the reaction feed, a mixture of sec-butanol and N2, is introduced to initiate the catalytic reaction. The sec-butanol enters the reaction apparatus via a liquid flow path, and the mass hourly space velocity (WHSV) of the sec-butanol is set to 12h⁻¹. -1N2 enters the reaction apparatus via a gas path, with the N2 flow rate set at 50 mL / min and the reaction pressure at 0.1 MPa. The pipeline is heated and insulated throughout to prevent condensation in the reactor. The product of the catalytic reaction is collected in a condenser and then discharged as liquid. A Shimadzu GC-2014C gas chromatograph equipped with an FID detector is used to quantitatively analyze the product. The calculated conversion rate of sec-butanol and the selectivity of methyl ethyl ketone are recorded in Table 1.

[0172] Table 1. Conversion rate of sec-butanol and selectivity of methyl ethyl ketone

[0173] Cu loading Surface defect content of Cu nanoparticles (%) <![CDATA[The heating rate of H2 / Ar-H2-N2 (°C / min) a > Conversion rate of sec-butanol (%) Selectivity of methyl ethyl ketone (%) Example 1 30wt% 70 1-20-10 80 99.6 Example 2 30wt% 65 10-1-10 76.4 99.4 Example 3 Example 3 30wt% 62 1-10-20 65.9 99.9 Example 4 36wt% 60 1-20-10 70 99.8 Example 5 36wt% 57 10-1-10 61.9 99.6 Example 6 36wt% 52 1-10-20 58 99.9 Example 7 24wt% 63 1-20-10 66.4 99.5 Example 8 24wt% 58 10-1-10 63.6 99.7 Example 9 24wt% 54 1-10-20 60.7 99.9 Comparative Example 1 30wt% 18 1- / - / 41.2 99.1 Comparative Example 2 30wt% 16 / -10- / 34.6 99.7 Comparative Example 3 30wt% 10 / -20- / 28.7 98.7 Comparative Example 4 36wt% 14 / -1- / 30.8 99.5 Comparative Example 5 36wt% 12 / -10- / 29.7 99.7 Comparative Example 6 36wt% 6 / -20- / 20.5 99.3 Comparative Example 7 24wt% 17 / -1- / 38.2 99.9 Comparative Example 8 24wt% 15 / -10- / 31.8 99.6 Comparative Example 9 24wt% 8 / -20- / 24.6 99.8 Comparative Example 10 — — 1-20-10 6.5 99.4 Comparative Example 11 — — 10-1-10 5.7 99.2 Comparative Example 12 — — 1-10-20 4.1 99.8 Comparative Example 13 — — 1- / - / 2.1 99.3 Comparative Example 14 — — 10- / - / 1.8 99.4 Comparative Example 15 — — 20- / - / 0.9 98.9

[0174] a The heating rates of the calcined sample D in step 2 under H2 / Ar mixed atmosphere, pure H2 atmosphere, and N2 atmosphere, respectively, are indicated by " / ". " / " indicates that this step was not included in the comparative example.

[0175] As shown in Table 1, compared with the comparative examples, the catalysts of Examples 1-9 exhibit higher sec-butanol dehydrogenation activity and achieve higher sec-butanol conversion rates. This is because the present invention employs a special treatment method, which involves reducing the catalyst under H2 / Ar, pure H2, and N2 atmospheres using specific heating rates and holding times. This results in a catalyst structure with a high surface defect content of Cu nanoparticles, which better promotes sec-butanol dehydrogenation and significantly enhances the dehydrogenation activity. In particular, catalyst 1 achieves an sec-butanol conversion rate of 80% and a methyl ethyl ketone selectivity of 99.6% at a reaction temperature of 220°C. Furthermore, catalysts 1-9 showed no significant deactivation after 16 hours of reaction. Therefore, the catalysts of the present invention can achieve stable operation at high conversion rates for extended periods.

[0176] Comparative Examples 1-9, lacking the aforementioned special treatment method, showed a significant decrease in the surface defect content of Cu nanoparticles, resulting in a corresponding significant decrease in the conversion rate of sec-butanol. Comparative Examples 10-15, lacking Cu nanoparticles with catalytically active centers, exhibited a significant decrease in the conversion rate of sec-butanol.

[0177] The embodiments described above are merely illustrative of several implementations of the present invention, designed to facilitate a detailed understanding of the technical solutions of the present invention. However, they should not be construed as limiting the scope of patent protection. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A method for preparing a supported Cu catalyst for the dehydrogenation of sec-butanol to methyl ethyl ketone, characterized in that, The method includes the following steps: Step 1: Preparation of copper-zinc-aluminum hydrotalcite Take 50-100 mmol of Cu(NO3)2•3H2O, 20-200 mmol of Zn(NO3)2•6H2O, and 20-200 mmol of Al(NO3)3•9H2O, and place them in a beaker containing 100-300 mL of deionized water. Stir until completely dissolved to obtain salt solution A. Weigh 20-200 mmol of Na2CO3 and 100-500 mmol of NaOH and place them in a beaker containing 200-500 mL of deionized water. Stir until completely dissolved to obtain alkaline solution B. Place alkaline solution B in a 1000 mL four-necked flask and incubate at room temperature. The mixture is stirred at a speed of 600-1000 r / min. Salt solution A is added dropwise to a four-necked flask at a rate of 1-3 mL / min. After salt solution A is completely added, the final pH value is controlled to be 9-12. The mixture is crystallized at a constant temperature in a water bath at 20-40℃ for 5-24 h. Then, the temperature is increased to 70-90℃ and crystallized at a constant temperature for 5-18 h. Solid sample C is obtained by vacuum filtration. Solid sample C is washed with deionized water until neutral and then dried in an oven at 100-200℃ for 6-12 h. After cooling, it is ground to obtain copper-zinc-aluminum hydrotalcite powder, denoted as CuZnAl-LDHs, which is then dried and stored. Step 2: Preparation of supported Cu nanoparticle catalysts The CuZnAl-LDHs powder was calcined in air at a temperature of 200-500℃, a heating rate of 1-10℃ / min, and held for 10-60min to obtain calcined sample D. The calcined sample D was then heated to 100-150℃ in an H2 / Ar mixed atmosphere and held for 30-120min. The volume ratio of H2 to Ar in the H2 / Ar mixed atmosphere was (1-3):(7-9). Then, the atmosphere was switched to pure H2, and the temperature was increased to 180-300℃ and held for 30-120min. Finally, the temperature was increased to 320-550℃ in an N2 atmosphere and held for 40-90min. After cooling to room temperature, the supported Cu nanoparticle catalyst was obtained. The catalyst consists of Cu nanoparticle active centers rich in surface defects and a zinc-aluminum layered bimetallic oxide matrix. It is characterized by CO adsorption infrared spectroscopy. The surface defects are composed of Cu nanoparticles, and the surface defect content is 52-70% based on the surface area of ​​Cu nanoparticles.

2. The preparation method according to claim 1, characterized in that, In step 2, the heating rate under the H2 / Ar mixed atmosphere is 1-50℃ / min.

3. The preparation method according to claim 1, characterized in that, In step 2, the heating rate under pure H2 atmosphere is 1-50℃ / min.

4. The preparation method according to claim 1, characterized in that, In step 2, the heating rate under the N2 atmosphere is 1-50℃ / min.

5. A supported Cu catalyst prepared by the preparation method according to any one of claims 1-4, characterized in that, The catalyst has the structural formula Cu-ZnAl-LDO, and the molar ratio of Cu, Zn, and Al in the catalyst is (1-4):(1-3):(1-3). In the XRD pattern of the catalyst, the characteristic peaks appearing at 31.7°, 34.8°, 36.3°, 47.5°, 56.6°, 62.9°, and 67.9° are the characteristic diffraction peaks of ZnO (100), (002), (101), (102), (110), (103), and (112), respectively. Similarly, the characteristic peak appearing at 43.2° is the (111) crystal plane of Cu.

6. The supported Cu catalyst according to claim 5, characterized in that, Aberration-corrected electron microscopy revealed that the active centers of the catalyst were Cu nanoparticles rich in surface defects with a particle size of 3-6 nm. These active centers were uniformly dispersed on a ZnAl-LDO support. ICP testing showed that, based on the total mass of the catalyst, the Cu loading of the active centers was 24-30 wt% (calculated as metal elements).

7. A method for preparing methyl ethyl ketone by dehydrogenation of sec-butanol, characterized in that, The supported Cu catalyst prepared by the preparation method according to any one of claims 1-4, or the supported Cu catalyst according to claim 5 or 6, specifically includes the following steps: The catalyst is granulated to 20-40 mesh and loaded into a reaction tube. The reaction tube is then placed into a fixed-bed reactor, and the apparatus is leak-tested. After leak testing, the catalyst is pre-activated by introducing H2 for pretreatment and maintaining the temperature at 300-600℃ for 0.5-3 hours. After cooling to 200-250℃, the reaction feed is introduced to carry out the catalytic reaction. The reaction feed is a mixture of sec-butanol and N2. The sec-butanol enters the reaction apparatus via a liquid path, and the mass hourly space velocity (WHSV) of the sec-butanol is set to 12-15 h⁻¹. -1 N2 enters the reaction apparatus via a gas path; the pipeline is heated and insulated throughout to prevent condensation in the reactor; the product of the catalytic reaction is collected in a condenser and discharged as liquid. The product is quantitatively analyzed using a gas chromatograph, and the conversion rate of sec-butanol is calculated to be 58-90%, and the selectivity of methyl ethyl ketone is over 99%.

8. The method according to claim 7, characterized in that, In the step of preparing methyl ethyl ketone by dehydrogenation of sec-butanol, the reaction pressure is 0.1-0.8 MPa.

9. The method according to claim 7, characterized in that, In the step of preparing methyl ethyl ketone by dehydrogenation of sec-butanol, the H2 flow rate is 10-100 mL / min.

10. The method according to claim 7, characterized in that, In the step of preparing methyl ethyl ketone by dehydrogenation of sec-butanol, the N2 flow rate is 10-100 mL / min.

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