Multifunctional titanium silical TS-1 nanosheet and preparation method and application thereof

Abstract

This application relates to the fields of molecular sieve synthesis and catalytic chemistry, disclosing a multifunctional titanium-silicon molecular sieve TS-1 nanosheet, its preparation method, and its applications. The nanosheet is prepared from 2 parts of TS-1 nanosheet support, 0-0.026 parts of gold source precursor, and 0-0.028 parts of palladium source precursor. The preparation process involves adding urea to a system containing tetrapropylammonium hydroxide and a silicon source to regulate morphology, adding a titanium source dropwise, and then hydrothermally crystallizing after alcohol removal to obtain the support. The support is then loaded with a metal active component and activated by impregnation. The nanosheet support grows in a confined manner along the b-axis to form a two-dimensional sheet structure. In applications, it catalyzes the in-situ generation of hydrogen peroxide from hydroxide in the same reaction system, and allows it to participate in the cyclohexanone ammoniation reaction to generate cyclohexanone oxime. This invention solves the problems of easy decomposition and storage and transportation safety risks associated with pre-prepared hydrogen peroxide, improves atom utilization and catalytic cycle stability, significantly shortens the process, reduces production costs, and improves process safety.

Description

Technical Field

[0001] This invention relates to the fields of molecular sieve synthesis and catalytic chemistry, specifically to multifunctional titanium-silicon molecular sieve TS-1 nanosheets, their preparation methods, and applications. Background Technology

[0002] The ammoniation of cyclohexanone is a core step in the industrial production of caprolactam. Currently, the liquid-phase ammoniation process of cyclohexanone mainly uses a pre-prepared hydrogen peroxide solution as the oxidant. Because the ammoniation reaction must be carried out at high temperatures and in an alkaline reaction medium, hydrogen peroxide exhibits strong instability under these conditions and is prone to non-productive decomposition. This chemical property necessitates the excessive addition of oxidant during the process to compensate for decomposition losses, thereby increasing production costs.

[0003] In terms of industrial logistics and safety, hydrogen peroxide production sites and ammonia oxime application centers often do not overlap, leading to safety hazards during long-distance transportation of high-concentration hydrogen peroxide. Industrially produced hydrogen peroxide typically needs to be concentrated to a high concentration, but this concentration must be repeated during the actual ammonia oxime reaction, resulting in energy waste in the initial concentration step. Furthermore, to inhibit the decomposition of hydrogen peroxide during storage and transportation, chemical stabilizers such as acids or halogens are usually added to the solution. The introduction of these substances not only accelerates the corrosion of metals in industrial reaction equipment but also puts pressure on subsequent environmental remediation efforts.

[0004] Regarding catalyst performance, the traditional titanium-silicon molecular sieve TS-1 exhibits a typical microporous structure, and its crystal morphology often results in long pore pathways. For reactants with large molecular sizes, such as cyclohexanone, the diffusion resistance within the pores is significant, limiting the mass transfer rate and directly restricting the effective utilization of the active sites within the molecular sieve. Therefore, developing a multifunctional catalytic system that can address both the stability and storage / transportation issues of the oxidant while optimizing the diffusion pathways of large molecules has become a current research direction for improving the efficiency of ammonia oxime processes. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides multifunctional titanium-silicon molecular sieve TS-1 nanosheets, their preparation method, and applications. It solves the problems of high production costs, significant storage and transportation safety risks, and stabilizer corrosion of equipment caused by the easy decomposition of added hydrogen peroxide in the liquid-phase cyclohexanone ammonium oxime process. It also solves the diffusion restriction problem of macromolecular reactants caused by the long micropore channel path of traditional TS-1 molecular sieves.

[0006] To achieve the above objectives, the present invention provides the following technical solution: In a first aspect, the present invention provides multifunctional titanium-silicon molecular sieve TS-1 nanosheets, employing the following technical solution: The multifunctional titanium-silicon molecular sieve TS-1 nanosheets are made from the following raw materials in parts by weight: 2 parts TS-1 nanosheet carrier; 0-0.026 parts gold source precursor; and 0-0.028 parts palladium source precursor.

[0007] By employing the above technical solution, the multifunctional titanium-silicon molecular sieve TS-1 nanosheets distribute redox metal centers and titanium active sites within the molecular sieve framework in a two-dimensional sheet structure. The underlying principle is that the TS-1 nanosheet support possesses a short b-axis characteristic, reducing mass transfer resistance for cyclohexanone molecules entering the pores and cyclohexanone oxime molecules leaving the active sites. The supported metal components, such as gold and palladium, form catalytic centers on the support surface and within the pores, activating in-situ hydrogen peroxide through hydrogen and oxygen reaction. Due to the physical proximity of the metal sites to the framework titanium sites, the generated hydrogen peroxide can directly diffuse to the titanium sites to participate in the ammonium oxime reaction, reducing thermal decomposition losses of the oxidant in the liquid phase system and improving oxidation efficiency.

[0008] Preferably, the gold source precursor is tetrachloroauric acid trihydrate; the palladium source precursor is selected from one or two of palladium acetate and palladium chloride; and the nanosheets are further loaded with one or more metal elements selected from Pt, Sn, Zn, and Ni.

[0009] By adopting the above technical solution and utilizing the synergistic effect between different metals to adjust the electronic structure of alloy particles, the selectivity of direct synthesis of hydrogen peroxide from hydrogen and oxygen can be controlled.

[0010] Preferably, the TS-1 nanosheet carrier is made from raw materials comprising the following molar ratios: tetraethyl orthosilicate 1; tetrabutyl titanate 0.01-0.06; tetrapropylammonium hydroxide 0.25; water 23; and urea 0.15-0.7.

[0011] Preferably, the TS-1 nanosheet carrier is grown in a restricted manner along the b-axis to form a two-dimensional sheet structure.

[0012] By employing the above technical solution, urea suppresses the crystal growth rate along the b-axis in the synthesis system through anisotropic confinement effect. Simultaneously, urea regulates the hydrolysis balance between the titanium and silicon sources, enabling titanium species to effectively enter the molecular sieve framework.

[0013] Secondly, this invention provides a method for preparing multifunctional titanium-silicon molecular sieve TS-1 nanosheets, employing the following technical solution: The preparation method of multifunctional titanium-silicon molecular sieve TS-1 nanosheets includes the following steps: S1: Mix tetrapropylammonium hydroxide solution, deionized water and tetraethyl orthosilicate to obtain a mixed solution, then add urea and continue stirring; S2: Add a titanium source to the solution obtained in S1 to obtain a titanium-containing mixture; S3: Heat the titanium-containing mixture to evaporate the alcohol solvent; S4: The product obtained in S3 was subjected to hydrothermal crystallization, followed by washing, drying and calcination to obtain TS-1 nanosheet carrier; S5: The TS-1 nanosheet carrier is immersed in a solvent containing a gold source precursor and / or a palladium source precursor; S6: The product obtained in S5 is dried, ground and activated to obtain the multifunctional titanium-silicon molecular sieve TS-1 nanosheets.

[0014] The process principle of the above technical solution is as follows: In stages S1-S4, the spontaneous dispersion of urea on the surface of TS-1 crystals is utilized to block the continuous growth along the b-axis through spatial effects, thereby obtaining a sheet-like support. In stages S5-S6, the metal precursor is distributed on the surface and channels of the sheet-like support using an impregnation method, and the metal components are reduced and anchored through subsequent activation treatment.

[0015] Preferably, in S1, the mass fraction of the tetrapropylammonium hydroxide solution is 25 wt%, and the amount of urea added is 0.901-4.205 g.

[0016] Preferably, in S2, the titanium source is tetrabutyl titanate, which is pre-dissolved in 0-17 g of isopropanol before being added.

[0017] By adopting the above technical solution, the thickness of the b-axis of the nanosheet and the titanium content can be controlled by precisely adjusting the amount of urea and the dilution concentration of the titanium source.

[0018] Preferably, in S4, the hydrothermal crystallization conditions are crystallization at 170 °C for 3 days; and the calcination conditions are calcination at 550 °C for 6 hours.

[0019] Preferably, in S5, the solvent is selected from one or more of water, ethanol, acetonitrile, and acetone; in S6, the activation treatment is performed at 400 °C for 3 h in an atmosphere selected from one or more of nitrogen, air, and hydrogen.

[0020] By adopting the above technical solution, the lattice integrity of the molecular sieve framework and the dispersion state of the loaded metal are maintained.

[0021] Thirdly, this invention provides the application of multifunctional titanium-silicon molecular sieve TS-1 nanosheets in the in-situ hydroxycyclohexanone ammoniumization reaction, employing the following technical solution: The application of multifunctional titanium-silicon molecular sieve TS-1 nanosheets in the in-situ hydroxycyclohexanone ammonium oxime reaction: In the same reaction system, the nanosheets catalyze the in-situ generation of hydrogen peroxide from H2 and O2. The generated hydrogen peroxide directly participates in the ammonium oxime reaction of cyclohexanone and ammonia to generate cyclohexanone oxime. The reaction conditions include the following mass ratios: cyclohexanone 1, catalyst 0-0.52, water 0-68.4, t-BuOH 0-68.4, NH3·H2O (28 wt%) 0-1.37, total gas pressure 4 MPa, containing 6.8% O2, 3.4% H2, and 89.8% N2, and the reaction is carried out at a rotation speed of 0-1200 r / min and a temperature of 60-90 ℃ for 0-4 h.

[0022] By employing the above technical solution, this application achieves in-situ coupling of multifunctional catalytic sites. The specific reaction process is as follows: 1. Hydrogen and oxygen generate oxidant: Hydrogen and oxygen are activated and reacted on the metal active sites supported on the nanosheet to generate hydrogen peroxide molecules.

[0023] 2. Hydrogen peroxide migration: The generated hydrogen peroxide molecules desorb from the metal surface and move towards the active sites of the framework titanium through the short-path channels of the sheet-like structure.

[0024] 3. Coupled ammonia oxime: At the active site of the skeletal titanium, cyclohexanone reacts with ammonia and hydrogen peroxide that has migrated there to generate cyclohexanone oxime.

[0025] This process is completed within the same microscale, reducing the residence time of hydrogen peroxide in the bulk liquid phase and lowering the probability of side reactions.

[0026] This invention provides multifunctional titanium-silicon molecular sieve TS-1 nanosheets, their preparation method, and applications. It offers the following advantages: 1. This invention reduces molecular mass transfer resistance by using a urea-assisted synthesis process to prepare TS-1 nanosheets with short b-axis characteristics, shortening the diffusion path of reactant molecules within the micropores of the molecular sieve. This morphological feature improves the contact efficiency between macromolecules such as cyclohexanone and cyclohexanone oxime and the active sites of the titanium framework, thereby increasing the catalytic reaction rate and the utilization rate of the active sites.

[0027] 2. This invention simplifies the process and improves safety. By loading Au-Pd and other metal components onto nanosheets, it achieves the in-situ coupling of hydrogen and oxygen to generate hydrogen peroxide, which then directly participates in the ammonium oxime reaction. This process eliminates the need for additional pre-prepared hydrogen peroxide, avoiding energy losses and safety risks associated with the transportation, storage, and dilution of high-concentration oxidants. It also eliminates the corrosive effects of oxidant stabilizers on industrial equipment.

[0028] 3. This invention enhances the structural stability of the catalyst. The introduction of urea into the synthesis system regulates the hydrolysis rates of the silicon and titanium sources, ensuring the effective coordination of titanium species within the framework. Combined with the highly dispersed metal components achieved through the impregnation process, the catalyst exhibits excellent crystallinity and cycle stability under high-temperature, strongly alkaline reaction conditions. Attached Figure Description

[0029] Figure 1 This is a flowchart of the method of the present invention; Figure 2 The XRD pattern of the catalyst in Example 1 of this invention is shown below. Figure 3 This is a TEM image of the catalyst in Example 1 of the present invention; Figure 4 This is the XRD pattern of the catalyst in Comparative Example 1 of the present invention; Figure 5 This is a SEM image of the catalyst of Comparative Example 1 of the present invention; Figure 6 This is a TEM image of the catalyst of Comparative Example 1 of the present invention. Detailed Implementation

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Please see the appendix Figure 1 - Appendix Figure 6 This invention provides a multifunctional titanium-silicon molecular sieve TS-1 nanosheet, its preparation method, and its application.

[0032] raw material: The main raw materials and reagents used in the following examples and comparative examples have the following sources and specifications. Reagents not specifically mentioned are all commercially available analytical grade or higher grade products.

[0033] Tetraethyl orthosilicate, with the molecular formula C8H 20 O4Si. Tetrabutyl titanate, molecular formula C 16 H 36 O4Ti. Tetrapropylammonium hydroxide, molecular formula C 12 H 29 No, in this invention, an aqueous solution with a mass fraction of 25 wt% is used. Urea, molecular formula CH4N2O. Isopropanol, molecular formula C3H8O. Deionized water, molecular formula H2O.

[0034] Palladium acetate, molecular formula C4H6O4Pd. Tetrachloroauric acid trihydrate, molecular formula HAuCl4. 3H₂O. Palladium chloride, molecular formula PdCl₂. Tin tetrachloride pentahydrate, molecular formula SnCl₄. 5H₂O. Potassium tetrachloroplatinate, molecular formula K₂PtCl₄. Zinc nitrate, molecular formula Zn(NO₃)₂. Nickel nitrate, molecular formula Ni(NO₃)₂. Titanium dioxide, molecular formula TiO₂.

[0035] Ethanol, molecular formula C2H6O. Acetonitrile, molecular formula C2H3N. Acetone, molecular formula C3H6O. Diethylene glycol monoethyl ether, molecular formula C6H6O. 14 O3.

[0036] Cyclohexanone, with the molecular formula C6H 10 O. tert-Butanol, with the molecular formula C4H 10 O. Ammonia, in this invention, an aqueous solution with a mass fraction of 28 wt% is used. Nitrogen, with the molecular formula N2. Oxygen / nitrogen mixture, wherein the oxygen content is 21%. Hydrogen / nitrogen mixture, wherein the hydrogen content is 5%.

[0037] Among the above raw materials, the TS-1 nanosheet carrier is a non-commercially available material, and its specific preparation method is described in the subsequent preparation examples.

[0038] This section provides four preparation examples with different parameters, covering the endpoints and intermediate values ​​of the ratio range (including special process schemes for isopropanol-free synthesis).

[0039] Preparation Example 1: This preparation example provides a TS-1 nanosheet carrier, comprising the following steps: Raw materials were prepared according to a molar ratio of tetraethyl orthosilicate, tetrabutyl titanate, tetrapropylammonium hydroxide, deionized water, and urea of ​​1:0.033:0.25:23:0.5. First, 20.336 g of a 25 wt% tetrapropylammonium hydroxide solution and 26.148 g of deionized water were mixed and stirred for 30 min. Then, 20.833 g of tetraethyl orthosilicate was added, and after stirring for 2 h, 3 g of urea was added. In a separate beaker, 15.3 g of isopropanol was added, and 1.122 g of tetrabutyl titanate was added dropwise while stirring. After adding the liquid from the second beaker to the first beaker, the mixed solution was heated at 80 °C to evaporate the alcohol. Finally, the final solution was placed in a hydrothermal reactor with a polytetrafluoroethylene liner and crystallized at 170 °C for three days. The synthesized product was washed with deionized water until the filtrate was neutral, dried at 60 °C overnight, and calcined at 550 °C for 6 h to obtain the TS-1 nanosheet carrier.

[0040] Preparation Example 2: This preparation example provides a TS-1 nanosheet carrier prepared using an isopropanol-free method, comprising the following steps: Raw materials were prepared according to a molar ratio of tetraethyl orthosilicate, tetrabutyl titanate, tetrapropylammonium hydroxide, deionized water, and urea of ​​1:0.02:0.25:23:0.5. First, 20.336 g of a 25 wt% tetrapropylammonium hydroxide solution and 26.148 g of deionized water were mixed and stirred for 30 min. Then, 20.833 g of tetraethyl orthosilicate was added, and after stirring for 2 h, 3 g of urea was added. Under stirring conditions, 0.68 g of tetrabutyl titanate was added dropwise, and the mixed solution was then heated at 80 °C to evaporate the alcohol. Finally, the final solution was placed in a hydrothermal reactor with a polytetrafluoroethylene liner and crystallized at 170 °C for three days. The synthesized product was washed with deionized water until the filtrate was neutral, dried at 60 °C overnight, and calcined at 550 °C for 6 h to obtain the TS-1 nanosheet carrier.

[0041] Preparation Example 3: This preparation example provides a TS-1 nanosheet carrier with a low titanium and low urea ratio, comprising the following steps: Raw materials were prepared according to a molar ratio of tetraethyl orthosilicate, tetrabutyl titanate, tetrapropylammonium hydroxide, deionized water, and urea of ​​1:0.01:0.25:23:0.15. First, 20.336 g of a 25 wt% tetrapropylammonium hydroxide solution and 26.148 g of deionized water were mixed and stirred for 30 min. Then, 20.833 g of tetraethyl orthosilicate was added, and after stirring for 2 h, 0.901 g of urea was added. In a separate beaker, 17 g of isopropanol was added, and 0.34 g of tetrabutyl titanate was added dropwise while stirring. After adding the liquid from the second beaker to the first beaker, the mixed solution was heated at 80 °C to evaporate the alcohol. Finally, the final solution was placed in a hydrothermal reactor with a polytetrafluoroethylene liner and crystallized at 170 °C for three days. The synthesized product was washed with deionized water until the filtrate was neutral, dried at 60 °C overnight, and calcined at 550 °C for 6 h to obtain the TS-1 nanosheet carrier.

[0042] Preparation Example 4: This preparation example provides a TS-1 nanosheet carrier with a high titanium and high urea ratio, comprising the following steps: Raw materials were prepared according to a molar ratio of tetraethyl orthosilicate, tetrabutyl titanate, tetrapropylammonium hydroxide, deionized water, and urea of ​​1:0.06:0.25:23:0.7. First, 20.336 g of a 25 wt% tetrapropylammonium hydroxide solution and 26.148 g of deionized water were mixed and stirred for 30 min. Then, 20.833 g of tetraethyl orthosilicate was added, and the mixture was stirred for 2 h, followed by the addition of 4.204 g of urea. In a separate beaker, 15.3 g of isopropanol was added, and 2.04 g of tetrabutyl titanate was added dropwise while stirring. After adding the liquid from the second beaker to the first beaker, the mixture was heated at 80 °C to evaporate the alcohol. Finally, the final solution was placed in a hydrothermal reactor with a polytetrafluoroethylene liner and crystallized at 170 °C for three days. The synthesized product was washed with deionized water until the filtrate was neutral, dried at 60 °C overnight, and calcined at 550 °C for 6 h to obtain the TS-1 nanosheet carrier.

[0043] The present invention will be further described below through specific examples, but the present invention is not limited to the following embodiments.

[0044] Example 1: Preparation of TS-1 nanosheets: The molar ratio of tetraethyl orthosilicate: tetrabutyl titanate: tetrapropylammonium hydroxide: H₂O: urea was 1:0.033:0.25:23:0.5. First, 20.336 g of tetrapropylammonium hydroxide solution (25 wt%) and 26.148 g of deionized water were mixed and stirred for 30 min. Then, 20.833 g of tetraethyl orthosilicate was added, and the mixture was stirred for 2 h, followed by the addition of 3 g of urea. In a separate beaker, 15.3 g of isopropanol was added, and 1.122 g of tetrabutyl titanate was added dropwise while stirring. After adding the liquid from the second beaker to the first beaker, the Ti-containing solution was heated at 80 °C to evaporate the alcohol. Finally, the final solution was placed in a hydrothermal reactor with a polytetrafluoroethylene liner and crystallized at 170 °C for three days. The synthesized product was washed with deionized water until the filtrate was neutral, dried at 60 °C overnight, and calcined at 550 °C for 6 h.

[0045] First, 0.014 g of palladium acetate was dissolved in a mixed solution of 10 mL ethanol and 10 mL acetonitrile. After complete dissolution, 2 g of TS-1 nanosheets were added, and the mixture was stirred at room temperature for 1 h. Then, the temperature was raised to 85 °C and the ethanol and acetonitrile mixture was evaporated to dryness. The evaporated sample was redispersed in 60 mL of H₂O, and 0.013 g of tetrachloroauric acid trihydrate was added. After stirring at room temperature for 1 h, the temperature was raised to 85 °C and maintained for 16 h. The resulting sample was ground, calcined in air at 400 °C for 3 h, and then reduced at 400 °C for 3 h in a hydrogen atmosphere. The solid was then removed to obtain the catalyst.

[0046] The XRD characterization results of the Au-Pd / TS-1 nanosheet catalyst are as follows: Figure 1 As shown, the TEM characterization results are as follows: Figure 2 As shown in the figure, the prepared catalyst has a complete MFI crystal structure and high crystallinity, with a plate-like morphology. The metal is loaded on the TS-1 nanosheets and forms an Au-Pd alloy.

[0047] The following ingredients were added: 0.075 g catalyst, 0.196 g cyclohexanone, 7.5 g H2O, 5.9 g t-BuOH, and 0.243 g NH3. H2O (28wt%) was added to a 100 mL polytetrafluoroethylene liner and placed in a high-pressure reactor. The reactor was first purged three times with N2 to remove all internal air. Then, an O2 / N2 mixture with 21% O2 content was introduced at 1.3 MPa, followed by an H2 / N2 mixture with 5% H2 content to increase the internal pressure to 4.0 MPa. The reactor was then rotated at 800 r / min. -1 The reaction was carried out at 80 °C for 3 h. Once the reaction was stopped, the mixture was cooled to room temperature in an ice-water bath, and 6 g of ethanol and 0.15 g of diethylene glycol monoethyl ether were added. The catalyst was removed by centrifugation. Diethylene glycol monoethyl ether was used as an internal standard, and the reaction was detected by gas chromatography. The conversion of cyclohexanone and the selectivity for cyclohexanone oxime were calculated according to the following formula: Conversion rate (%) =

[0048] Selectivity (%) =

[0049] In the formula , and These represent the concentrations of cyclohexanone before the reaction, the concentration of cyclohexanone after the reaction, and the concentration of cyclohexanone oxime formed, respectively.

[0050] Catalyst activity evaluation results: The conversion rate of cyclohexanone was 94.7%, and the selectivity for cyclohexanone oxime was 96.6%.

[0051] Example 2: The preparation method of Au-Pd / TS-1 nanosheets is the same as that in Example 1, except that the Ti:Si ratio of the TS-1 nanosheets is replaced from 0.033:1 to 0.02:1, the amount of isopropanol added is changed from 15.3 g to 0 g, and 7.5 g H2O and 5.9 g t-BuOH are replaced with 2.5 g H2O and 10.9 g t-BuOH. The method includes the following steps: Preparation of TS-1 nanosheets: The molar ratio of tetraethyl orthosilicate: tetrabutyl titanate: tetrapropylammonium hydroxide: H₂O: urea was 1: : : : First, 20.336 g of tetrapropylammonium hydroxide solution (25 g) was added. 20.833 g of tetraethyl orthosilicate was added and stirred for 30 min with 26.148 g of deionized water. Then, 3 g of urea was added. While stirring, 0.68 g of tetrabutyl titanate was added dropwise, and the Ti-containing solution was heated at 80 °C. Finally, the final solution was placed in a hydrothermal reactor with a polytetrafluoroethylene liner and crystallized at 170 °C for three days. The synthesized product was washed with deionized water until the filtrate was neutral, dried overnight at 60 °C, and calcined at 550 °C for 6 h.

[0052] First, 0.014 g of palladium acetate was dissolved in a mixed solution of 10 mL ethanol and 10 mL acetonitrile. After complete dissolution, 2 g of TS-1 nanosheets were added, and the mixture was stirred at room temperature for 1 h. Then, the temperature was raised to 85 °C and the ethanol and acetonitrile mixture was evaporated to dryness. The evaporated sample was redispersed in 60 mL of H₂O, and 0.013 g of tetrachloroauric acid trihydrate was added. After stirring at room temperature for 1 h, the temperature was raised to 85 °C and maintained for 16 h. The resulting sample was ground, calcined in air at 400 °C for 3 h, and then reduced at 400 °C for 3 h in a hydrogen atmosphere. The solid was then removed to obtain the catalyst.

[0053] 0.075 g catalyst, 0.196 g cyclohexanone, 2.5 g H2O, 10.9 g t-BuOH, and 0.243 g... (28) Add to a 100 mL polytetrafluoroethylene liner, place in a high-pressure reactor, and first use... The reactor was purged three times to remove all internal air, and then filled with... Content of 21% The mixed gas pressure is 1.3 MPa, then it is charged. Content of 5% The mixed gas increases the gas pressure inside the reactor to 4.0 MPa at a rotation speed of 800 rpm. The reaction was carried out at 80 °C for 3 h. Once the reaction was stopped, the mixture was cooled to room temperature in an ice-water bath, and 6 g of ethanol and 0.15 g of diethylene glycol monoethyl ether were added. The catalyst was removed by centrifugation. Diethylene glycol monoethyl ether was used as an internal standard in the internal standard method, and the reaction was detected by gas chromatography.

[0054] Catalyst activity evaluation results: The conversion rate of cyclohexanone was 98.1%, and the selectivity for cyclohexanone oxime was 100%.

[0055] Example 3: The preparation method of Au-Pd / TS-1 nanosheets is the same as that in Example 1, except that the Ti:Si ratio of the TS-1 nanosheets is replaced from 0.033:1 to 0.01:1, the urea:Si ratio is replaced from 0.5:1 to 0.15:1, the amount of isopropanol added is changed from 15.3 g to 17 g, the amount of palladium acetate added is changed from 0.014 g to 0 g, the amount of tetrachloroauric acid trihydrate is changed from 0.013 g to 0.026 g, the amount of acetonitrile used to dissolve palladium acetate is changed from 10 mL to 0 mL, the amount of ethanol is changed from 10 mL to 0 mL, and the amount of water used to dissolve tetrachloroauric acid trihydrate is changed from 60 mL to 100 mL. The method includes the following steps: Preparation of TS-1 nanosheets: The molar ratio of tetraethyl orthosilicate: tetrabutyl titanate: tetrapropylammonium hydroxide: H₂O: urea was 1: : : : First, 20.336 g of tetrapropylammonium hydroxide solution (25 g) was added. The solution was mixed with 26.148 g of deionized water and stirred for 30 min. 20.833 g of tetraethyl orthosilicate was added, and the mixture was stirred for 2 h, followed by the addition of 0.901 g of urea. In a separate beaker, 17 g of isopropanol was added, and 0.34 g of tetrabutyl titanate was added dropwise while stirring. After adding the liquid from the second beaker to the first beaker, the Ti-containing solution was heated at 80 °C to evaporate the alcohol. Finally, the final solution was placed in a hydrothermal reactor with a polytetrafluoroethylene liner and crystallized at 170 °C for three days. The synthesized product was washed with deionized water until the filtrate was neutral, dried at 60 °C overnight, and calcined at 550 °C for 6 h.

[0056] 0.026 g of tetrachloroauric acid trihydrate was dissolved in 100 mL of H₂O. After complete dissolution, 2 g of TS-1 nanosheets were added, and the mixture was stirred at room temperature for 1 h. The temperature was then raised to 85 °C and held for 16 h. The resulting sample was ground, calcined in air at 400 °C for 3 h, and then reduced at 400 °C for 3 h in a hydrogen atmosphere. The solid was then removed to obtain the catalyst.

[0057] 0.075 g catalyst, 0.196 g cyclohexanone, 7.5 g H2O, 5.9 g t-BuOH, and 0.243 g... (28) Add to a 100 mL polytetrafluoroethylene liner, place in a high-pressure reactor, and first use... The reactor was purged three times to remove all internal air, and then filled with... Content of 21% The mixed gas pressure is 1.3 MPa, then it is charged. Content of 5% The mixed gas increases the gas pressure inside the reactor to 4.0 MPa at a rotation speed of 800 rpm. The reaction was carried out at 80°C for 3 h. Once the reaction was stopped, the mixture was cooled to room temperature in an ice-water bath, and 6 g of ethanol and 0.15 g of diethylene glycol monoethyl ether were added. The catalyst was removed by centrifugation. Diethylene glycol monoethyl ether was used as an internal standard in the internal standard method, and the reaction was detected by gas chromatography.

[0058] Catalyst activity evaluation results: The conversion rate of cyclohexanone was 5.55%, and the selectivity for cyclohexanone oxime was 18.49%.

[0059] Example 4: The preparation method of Au-Pd / TS-1 nanosheets is the same as that in Example 1, except that the Ti / Si ratio of the TS-1 nanosheets is replaced by 0.06:1, the urea:Si ratio is replaced by 0.7:1, the amount of palladium acetate is replaced by 0.014 g, the amount of tetrachloroauric acid trihydrate is replaced by 0 g, the amount of acetonitrile used to dissolve palladium acetate is replaced by 40 mL, the amount of ethanol is replaced by 40 mL, and the amount of water used to dissolve tetrachloroauric acid trihydrate is replaced by 0 mL. The method includes the following steps: Preparation of TS-1 nanosheets: The molar ratio of tetraethyl orthosilicate: tetrabutyl titanate: tetrapropylammonium hydroxide: H₂O: urea was 1: : : : First, 20.336 g of tetrapropylammonium hydroxide solution (25 g) was added. The solution was mixed with 26.148 g of deionized water and stirred for 30 min. 20.833 g of tetraethyl orthosilicate was added, and the mixture was stirred for 2 h, followed by the addition of 4.204 g of urea. In a separate beaker, 15.3 g of isopropanol was added, and 2.04 g of tetrabutyl titanate was added dropwise while stirring. After adding the liquid from the second beaker to the first beaker, the Ti-containing solution was heated at 80 °C to evaporate the alcohol. Finally, the final solution was placed in a hydrothermal reactor with a polytetrafluoroethylene liner and crystallized at 170 °C for three days. The synthesized product was washed with deionized water until the filtrate was neutral, dried at 60 °C overnight, and calcined at 550 °C for 6 h.

[0060] 0.028 g of palladium acetate was dissolved in a mixed solution of 40 mL ethanol and 40 mL acetonitrile. After complete dissolution, 2 g of TS-1 nanosheets were added, and the mixture was stirred at room temperature for 1 h. The temperature was then raised to 85 °C and held for 16 h. The resulting sample was ground, calcined in air at 400 °C for 3 h, and then reduced at 400 °C for 3 h in a hydrogen atmosphere. The solid was then removed to obtain the catalyst.

[0061] 0.075 g catalyst, 0.196 g cyclohexanone, 7.5 g H2O, 5.9 g t-BuOH, and 0.243 g... (28) Add to a 100 mL polytetrafluoroethylene liner, place in a high-pressure reactor, and first use... The reactor was purged three times to remove all internal air, and then filled with... Content of 21% The mixed gas pressure is 1.3 MPa, then it is charged. Content of 5% The mixed gas increases the gas pressure inside the reactor to 4.0 MPa at a rotation speed of 800 rpm. 80 The reaction was allowed to proceed for 3 hours. Once the reaction was stopped, the mixture was cooled to room temperature in an ice-water bath, and 6 g of ethanol and 0.15 g of diethylene glycol monoethyl ether were added. The catalyst was removed by centrifugation. Diethylene glycol monoethyl ether was used as an internal standard in the internal standard method, and the reaction was detected by gas chromatography.

[0062] Catalyst activity evaluation results: The conversion rate of cyclohexanone was 52.76%, and the selectivity for cyclohexanone oxime was 79.9%.

[0063] Example 5: The preparation method of Au-Pd / TS-1 nanosheets is the same as that in Example 1, except that the order of impregnation of metals is changed from Pd to Au to Au to Pd, the impregnation time of palladium acetate is changed from 1 h to 4 h, the impregnation time of tetrachloroauric acid trihydrate is changed from 1 h to 4 h, the holding time is changed from 16 h to 8 h, and the post-treatment method is changed from calcination at 400 °C in air for 3 h followed by reduction at 400 °C in a hydrogen atmosphere for 3 h to no treatment. The method includes the following steps: Preparation of TS-1 nanosheets: The molar ratio of tetraethyl orthosilicate: tetrabutyl titanate: tetrapropylammonium hydroxide: H₂O: urea was 1: : : : First, 20.336 g of tetrapropylammonium hydroxide solution (25 g) was added. The solution was mixed with 26.148 g of deionized water and stirred for 30 min. 20.833 g of tetraethyl orthosilicate was added, and the mixture was stirred for 2 h, followed by the addition of 4.204 g of urea. In a separate beaker, 15.3 g of isopropanol was added, and 1.122 g of tetrabutyl titanate was added dropwise while stirring. After adding the liquid from the second beaker to the first beaker, the Ti-containing solution was heated at 80 °C to evaporate the alcohol. Finally, the final solution was placed in a hydrothermal reactor with a polytetrafluoroethylene liner and crystallized at 170 °C for three days. The synthesized product was washed with deionized water until the filtrate was neutral, dried at 60 °C overnight, and calcined at 550 °C for 6 h.

[0064] First, 0.013 g of tetrachloroauric acid trihydrate was dissolved in 60 mL of H₂O. After complete dissolution, 2 g of TS-1 nanosheets were added, and the mixture was stirred at room temperature for 4 h. Then, the temperature was raised to 85 °C and the water was evaporated to dryness. The evaporated sample was redispersed in a mixed solution of 10 mL of ethanol and 10 mL of acetonitrile, and 0.014 g of palladium acetate was added. After stirring at room temperature for 4 h, the temperature was raised to 85 °C and maintained for 8 h. The resulting sample was then ground to obtain the catalyst.

[0065] 0.075 g catalyst, 0.196 g cyclohexanone, 7.5 g H2O, 5.9 g t-BuOH, and 0.243 g... (28) Add to a 100 mL polytetrafluoroethylene liner, place in a high-pressure reactor, and first use... The reactor was purged three times to remove all internal air, and then filled with... Content of 21% The mixed gas pressure is 1.3 MPa, then it is charged. Content of 5% The mixed gas increases the gas pressure inside the reactor to 4.0 MPa at a rotation speed of 800 rpm. The reaction was carried out at 80 °C for 3 h. Once the reaction was stopped, the mixture was cooled to room temperature in an ice-water bath, and 6 g of ethanol and 0.15 g of diethylene glycol monoethyl ether were added. The catalyst was removed by centrifugation. Diethylene glycol monoethyl ether was used as an internal standard in the internal standard method, and the reaction was detected by gas chromatography.

[0066] Catalyst activity evaluation results: The conversion rate of cyclohexanone was 92.35%, and the selectivity for cyclohexanone oxime was 86.65%.

[0067] Example 6: The preparation method of Au-Pd / TS-1 nanosheets is the same as that in Example 1, except that 0.014 g of palladium acetate is replaced with 0.221 g of palladium chloride (5 g / L). in The loading order was changed from Pd first and then Au to simultaneous loading of Au and Pd; the solvent for impregnating Pd was changed from 10 mL ethanol and 10 mL acetonitrile to 60 mL water; and the post-treatment method was changed from calcination in air at 400 °C for 3 h followed by reduction at 400 °C for 3 h in a hydrogen atmosphere to calcination in air at 400 °C for 3 h only. The process included the following steps: Preparation of TS-1 nanosheets: The molar ratio of tetraethyl orthosilicate: tetrabutyl titanate: tetrapropylammonium hydroxide: H₂O: urea was 1: : : : First, 20.336 g of tetrapropylammonium hydroxide solution (25 g) was added. The solution was mixed with 26.148 g of deionized water and stirred for 30 min. 20.833 g of tetraethyl orthosilicate was added, and the mixture was stirred for 2 h, followed by the addition of 3 g of urea. In a separate beaker, 15.3 g of isopropanol was added, and 1.122 g of tetrabutyl titanate was added dropwise while stirring. After adding the liquid from the second beaker to the first beaker, the Ti-containing solution was heated at 80 °C to evaporate the alcohol. Finally, the final solution was placed in a hydrothermal reactor with a polytetrafluoroethylene liner and crystallized at 170 °C for three days. The synthesized product was washed with deionized water until the filtrate was neutral, dried overnight at 60 °C, and calcined at 550 °C for 6 h.

[0068] First, 0.013 g of tetrachloroauric acid trihydrate and 0.221 g of palladium chloride (5 in Simultaneously, it was dissolved in 60 mL of H2O. After complete dissolution, 2 g of TS-1 nanosheets were added, and the mixture was stirred at room temperature for 1 h. The temperature was then raised to 85 ℃ and held for 16 h. The resulting sample was ground and calcined in air at 400 ℃ for 3 h. The solid was then removed to obtain the catalyst.

[0069] 0.075 g catalyst, 0.196 g cyclohexanone, 7.5 g H2O, 5.9 g t-BuOH, and 0.243 g... (28) Add to a 100 mL polytetrafluoroethylene liner, place in a high-pressure reactor, and first use... The reactor was purged three times to remove all internal air, and then filled with... Content of 21% The mixed gas pressure is 1.3 MPa, then it is charged. Content of 5% The mixed gas increases the gas pressure inside the reactor to 4.0 MPa at a rotation speed of 800 rpm. 80 The reaction was allowed to proceed for 3 hours. Once the reaction was stopped, the mixture was cooled to room temperature in an ice-water bath, and 6 g of ethanol and 0.15 g of diethylene glycol monoethyl ether were added. The catalyst was removed by centrifugation. Diethylene glycol monoethyl ether was used as an internal standard in the internal standard method, and the reaction was detected by gas chromatography.

[0070] Catalyst activity evaluation results: The conversion rate of cyclohexanone was 21.84%, and the selectivity for cyclohexanone oxime was 61.37%.

[0071] Example 7: The preparation method of Sn-Pd / TS-1 nanosheets is the same as that in Example 1, except that the solvent for dissolving palladium acetate is replaced with 20 mL acetone instead of 10 mL ethanol and 10 mL acetonitrile; 0.013 g tetrachloroauric acid trihydrate is replaced with 0.017 g tin tetrachloride pentahydrate; and the post-treatment method is changed from calcination at 400 °C for 3 h in air followed by reduction at 400 °C for 3 h in a hydrogen atmosphere to calcination at 400 °C for 3 h in a nitrogen atmosphere. The method includes the following steps: Preparation of TS-1 nanosheets: The molar ratio of tetraethyl orthosilicate: tetrabutyl titanate: tetrapropylammonium hydroxide: H₂O: urea was 1: : : : First, 20.336 g of tetrapropylammonium hydroxide solution (25 g) was added. The solution was mixed with 26.148 g of deionized water and stirred for 30 min. 20.833 g of tetraethyl orthosilicate was added, and the mixture was stirred for 2 h, followed by the addition of 3 g of urea. In a separate beaker, 15.3 g of isopropanol was added, and 1.122 g of tetrabutyl titanate was added dropwise while stirring. After adding the liquid from the second beaker to the first beaker, the Ti-containing solution was heated at 80 °C to evaporate the alcohol. Finally, the final solution was placed in a hydrothermal reactor with a polytetrafluoroethylene liner and crystallized at 170 °C for three days. The synthesized product was washed with deionized water until the filtrate was neutral, dried overnight at 60 °C, and calcined at 550 °C for 6 h.

[0072] First, 0.014 g of palladium acetate was dissolved in 20 mL of acetone. After complete dissolution, 2 g of TS-1 nanosheets were added, and the mixture was stirred at room temperature for 1 h. Then, the temperature was raised to 85 °C and the acetone solvent was evaporated to dryness. The evaporated sample was redispersed in 60 mL of H₂O, and 0.017 g of tin tetrachloride pentahydrate was added. The mixture was stirred at room temperature for 1 h, and then the temperature was raised to 85 °C and maintained for 16 h. The resulting sample was ground and calcined at 400 °C for 3 h under nitrogen atmosphere. The solid was then removed to obtain the catalyst.

[0073] 0.075 g catalyst, 0.196 g cyclohexanone, 7.5 g H2O, 5.9 g t-BuOH, and 0.243 g... (28) Add to a 100 mL polytetrafluoroethylene liner, place in a high-pressure reactor, and first use... The reactor was purged three times to remove all internal air, and then filled with... Content of 21% The mixed gas pressure is 1.3 MPa, then it is charged. Content of 5% The mixed gas increases the gas pressure inside the reactor to 4.0 MPa at a rotation speed of 800 rpm. The reaction was carried out at 80°C for 3 h. Once the reaction was stopped, the mixture was cooled to room temperature in an ice-water bath, and 6 g of ethanol and 0.15 g of diethylene glycol monoethyl ether were added. The catalyst was removed by centrifugation. Diethylene glycol monoethyl ether was used as an internal standard in the internal standard method, and the reaction was detected by gas chromatography.

[0074] Catalyst activity evaluation results: The conversion rate of cyclohexanone was 46.83%, and the selectivity for cyclohexanone oxime was 92.63%.

[0075] Example 8: The preparation method of Pt-Pd / TS-1 nanosheets is the same as that in Example 1, except that 0.013 g of tetrachloroauric acid trihydrate is replaced with 0.022 g of potassium tetrachloroplatinate, and the post-treatment method is changed from calcination at 400 °C for 3 h in air followed by reduction at 400 °C for 3 h in a hydrogen atmosphere to calcination at 400 °C for 3 h in a nitrogen atmosphere followed by reduction at 400 °C for 3 h in a hydrogen atmosphere. The method includes the following steps: Preparation of TS-1 nanosheets: The molar ratio of tetraethyl orthosilicate: tetrabutyl titanate: tetrapropylammonium hydroxide: H₂O: urea was 1: : : : First, 20.336 g of tetrapropylammonium hydroxide solution (25 g) was added. Mix 26.148 g of deionized water and stir for 30 min. Add 20.833 g of tetraethyl orthosilicate and stir for 2 h, then add 3 g of urea. In a separate beaker, add 15.3 g of isopropanol and add 1.122 g of tetrabutyl titanate dropwise while stirring. After adding the liquid from the second beaker to the first beaker, heat the Ti-containing solution at 80 °C. The alcohol was evaporated by heating. Finally, the final solution was placed in a hydrothermal reactor lined with polytetrafluoroethylene and crystallized at 170 °C for three days. The synthesized product was washed with deionized water until the filtrate was neutral, dried at 60 °C overnight, and calcined at 550 °C for 6 h.

[0076] First, 0.014 g of palladium acetate was dissolved in a mixed solution of 10 mL ethanol and 10 mL acetonitrile. After complete dissolution, 2 g of TS-1 nanosheets were added, and the mixture was stirred at room temperature for 1 h. Then, the temperature was raised to 85°C. The mixed solvent of ethanol and acetonitrile was evaporated to dryness. The evaporated sample was redispersed in 60 mL of H₂O, and 0.022 g of potassium tetrachloroplatinate was added. After stirring at room temperature for 1 h, the temperature was raised to 85 °C and held for 16 h. The resulting sample was ground, calcined at 400 °C for 3 h in nitrogen atmosphere, and then reduced at 400 °C for 3 h in hydrogen atmosphere. The solid was then collected to obtain the catalyst.

[0077] 0.075 g catalyst, 0.196 g cyclohexanone, 7.5 g H2O, 5.9 g t-BuOH, and 0.243 g... (28) Add to a 100 mL polytetrafluoroethylene liner, place in a high-pressure reactor, and first use... The reactor was purged three times to remove all internal air, and then filled with... Content of 21% The mixed gas pressure is 1.3 MPa, then it is charged. Content of 5% The mixed gas increases the gas pressure inside the reactor to 4.0 MPa at a rotation speed of 800 rpm. 80 The reaction was allowed to proceed for 3 hours. Once the reaction was stopped, the mixture was cooled to room temperature in an ice-water bath, and 6 g of ethanol and 0.15 g of diethylene glycol monoethyl ether were added. The catalyst was removed by centrifugation. Diethylene glycol monoethyl ether was used as an internal standard in the internal standard method, and the reaction was detected by gas chromatography.

[0078] Catalyst activity evaluation results: The conversion rate of cyclohexanone was 88.85%, and the selectivity for cyclohexanone oxime was 83.13%.

[0079] Example 9: Zn-Pd / The preparation method of / TS-1 nanosheets is the same as that in Example 1, except that 0.013 g of tetrachloroauric acid trihydrate is replaced with 0.01 g of zinc nitrate, the post-treatment method is changed from calcination at 400 °C for 3 h in air followed by reduction at 400 °C for 3 h in a hydrogen atmosphere to reduction at 400 °C for 3 h in a hydrogen atmosphere, and the support is changed from TS-1 nanosheets to... And 0.075 g Zn-Pd / was added during the reaction. And 0.075 g TS-1 nanosheets. The process includes the following steps: Preparation of TS-1 nanosheets: Following the formula: tetraethyl orthosilicate: tetrabutyl titanate: tetrapropylammonium hydroxide: The molar ratio of urea is 1: : : : First, 20.336 g of tetrapropylammonium hydroxide solution (25 g) was added. The solution was mixed with 26.148 g of deionized water and stirred for 30 min. 20.833 g of tetraethyl orthosilicate was added, and the mixture was stirred for 2 h, followed by the addition of 3 g of urea. In a separate beaker, 15.3 g of isopropanol was added, and 1.122 g of tetrabutyl titanate was added dropwise while stirring. After adding the liquid from the second beaker to the first beaker, the Ti-containing solution was heated at 80 °C to evaporate the alcohol. Finally, the final solution was placed in a hydrothermal reactor with a polytetrafluoroethylene liner and crystallized at 170 °C for three days. The synthesized product was washed with deionized water until the filtrate was neutral, dried overnight at 60 °C, and calcined at 550 °C for 6 h.

[0080] First, dissolve 0.014 g of palladium acetate in a mixed solution of 10 mL ethanol and 10 mL acetonitrile. After complete dissolution, add 2 g of... After stirring at room temperature for 1 h, the temperature was raised to 85 °C to evaporate the mixed solvent of ethanol and acetonitrile. The evaporated sample was redispersed in 60 mL of H2O, and 0.01 g of zinc nitrate was added. After stirring at room temperature for 1 h, the temperature was raised to 85 °C and maintained for 16 h. The resulting sample was ground and reduced at 400 °C for 3 h in a hydrogen atmosphere. The solid was then removed to obtain the catalyst.

[0081] 0.075 g Zn-Pd / 0.075 g TS-1 nanosheets, 0.196 g cyclohexanone, 7.5 g H2O, 5.9 gt-BuOH, 0.243 g (28) Add to a 100 mL polytetrafluoroethylene liner, place in a high-pressure reactor, and first use... The reactor was purged three times to remove all internal air, and then filled with... Content of 21% The mixed gas pressure is 1.3 MPa, then it is charged. Content of 5% The mixed gas increases the gas pressure inside the reactor to 4.0 MPa at a rotation speed of 800 rpm. The reaction was carried out at 80 °C for 3 h. Once the reaction was stopped, the mixture was cooled to room temperature in an ice-water bath, and 6 g of ethanol and 0.15 g of diethylene glycol monoethyl ether were added. The catalyst was removed by centrifugation. Diethylene glycol monoethyl ether was used as an internal standard in the internal standard method, and the reaction was detected by gas chromatography.

[0082] Catalyst activity evaluation results: The conversion rate of cyclohexanone was 61.64%, and the selectivity for cyclohexanone oxime was 70.49%.

[0083] Example 10: The preparation method of Ni-Pd / TS-1 nanosheets is the same as that in Example 1, except that 0.013 g of tetrachloroauric acid trihydrate is replaced with 0.031 g of nickel nitrate, and 0.075 g of catalyst, 7.5 g of H2O, 5.9 g of t-BuOH, and 0.243 g of [other ingredients] are used. (28) Replace with 0.1 g catalyst, 0 g H2O, 13.4 g t-BuOH, and 0.268 g [other components]. (28) ), speed from 800 Replace with 1200 The reaction temperature was changed from 80℃ to 90℃, and the reaction time was changed from 3 h to 4 h. The process includes the following steps: Preparation of TS-1 nanosheets: Following the formula: tetraethyl orthosilicate: tetrabutyl titanate: tetrapropylammonium hydroxide: The molar ratio of urea is 1: : : : First, 20.336 g of tetrapropylammonium hydroxide solution (25 g) was added. The solution was mixed with 26.148 g of deionized water and stirred for 30 min. 20.833 g of tetraethyl orthosilicate was added, and the mixture was stirred for 2 h, followed by the addition of 3 g of urea. In a separate beaker, 15.3 g of isopropanol was added, and 1.122 g of tetrabutyl titanate was added dropwise while stirring. After adding the liquid from the second beaker to the first beaker, the Ti-containing solution was heated at 80 °C to evaporate the alcohol. Finally, the final solution was placed in a hydrothermal reactor with a polytetrafluoroethylene liner and crystallized at 170 °C for three days. The synthesized product was washed with deionized water until the filtrate was neutral, dried overnight at 60 °C, and calcined at 550 °C for 6 h.

[0084] First, 0.014 g of palladium acetate was dissolved in a mixed solution of 10 mL ethanol and 10 mL acetonitrile. After complete dissolution, 2 g of TS-1 nanosheets were added, and the mixture was stirred at room temperature for 1 h. Then, the temperature was raised to 85 °C to evaporate the ethanol and acetonitrile mixture to dryness. The evaporated sample was then redispersed in 60 mL of... 0.031 g of nickel nitrate was added to the mixture, and after stirring at room temperature for 1 h, the temperature was raised to 85 °C and held for 16 h. The resulting sample was ground, calcined in air at 400 °C for 3 h, and then reduced at 400 °C for 3 h in a hydrogen atmosphere. The solid was then removed to obtain the catalyst.

[0085] 0.1 g catalyst, 0.196 g cyclohexanone, 13.4 g t-BuOH, 0.268 g (28) Add to a 100 mL polytetrafluoroethylene liner, place in a high-pressure reactor, and first use... The reactor was purged three times to remove all internal air, and then filled with... Content of 21% The mixed gas pressure is 1.3 MPa, then it is charged. Content of 5% The mixed gas increases the gas pressure inside the reactor to 4.0 MPa at a rotation speed of 1200 rpm. The reaction was carried out at 90 °C for 4 h. Once the reaction was stopped, the mixture was cooled to room temperature in an ice-water bath, and 6 g of ethanol and 0.15 g of diethylene glycol monoethyl ether were added. The catalyst was removed by centrifugation. Diethylene glycol monoethyl ether was used as an internal standard in the internal standard method, and the reaction was detected by gas chromatography.

[0086] Catalyst activity evaluation results: The conversion rate of cyclohexanone was 41.59%, and the selectivity for cyclohexanone oxime was 79.5%.

[0087] Example 11: The preparation method of Au-Pd / TS-1 nanosheets is the same as that in Example 1, except that 7.5g of... 5.9 g t-BuOH was replaced with 13.4 g 0 g t-BuOH.

[0088] Catalyst activity evaluation results: The conversion rate of cyclohexanone was 55.44%, and the selectivity for cyclohexanone oxime was 32.69%.

[0089] Comparative Example 1: The preparation method for Au-Pd / conventional TS-1 is the same as that in Example 1, except that TS-1 nanosheets are replaced with conventional TS-1. The steps include: According to the formula: tetraethyl orthosilicate: tetrabutyl titanate: tetrapropylammonium hydroxide: The molar ratio is 1: : : First, 20.336 g of tetrapropylammonium hydroxide solution (25 g) was added. Mix 26.148 g of deionized water and stir for 30 min. Add 20.833 g of tetraethyl orthosilicate and stir for 2 h. In a separate beaker, add 15.3 g of isopropanol and add 1.122 g of tetrabutyl titanate dropwise while stirring. Add the liquid from the second beaker to the first beaker and heat the Ti-containing solution at 80 °C to evaporate the alcohol. Finally, place the final solution in a hydrothermal reactor with a polytetrafluoroethylene liner and crystallize at 170 °C for three days. Wash the synthesized product with deionized water until the filtrate is neutral, dry at 60 °C overnight, and calcine at 550 °C for 6 h.

[0090] First, 0.014 g of palladium acetate was dissolved in a mixed solution of 10 mL ethanol and 10 mL acetonitrile. After complete dissolution, 2 g of conventional TS-1 was added, and the mixture was stirred at room temperature for 1 h. Then, the temperature was raised to 85 °C to evaporate the ethanol and acetonitrile mixture to dryness. The evaporated sample was then redispersed in 60 mL of... 0.013 g of tetrachloroauric acid trihydrate was added to the mixture, and after stirring at room temperature for 1 h, the temperature was raised to 85 °C and held for 16 h. The resulting sample was ground, calcined in air at 400 °C for 3 h, and then reduced at 400 °C for 3 h in a hydrogen atmosphere. The solid was then removed to obtain the catalyst.

[0091] The prepared catalyst has a complete MFI crystal structure but low crystallinity and a spherical morphology. The metal is supported on the conventional TS-1 and forms an Au-Pd alloy.

[0092] 0.075 g catalyst, 0.196 g cyclohexanone, 7.5 g 5.9 g t-BuOH, 0.243 g (28) Add to a 100 mL polytetrafluoroethylene liner, place in a high-pressure reactor, and first use... The reactor was purged three times to remove all internal air, and then filled with... Content of 21% The mixed gas pressure is 1.3 MPa, then it is charged. Content of 5% The mixed gas increases the gas pressure inside the reactor to 4.0 MPa at a rotation speed of 800 rpm. The reaction was carried out at 80°C for 3 h. Once the reaction was stopped, the mixture was cooled to room temperature in an ice-water bath, and 6 g of ethanol and 0.15 g of diethylene glycol monoethyl ether were added. The catalyst was removed by centrifugation. Diethylene glycol monoethyl ether was used as an internal standard in the internal standard method, and the reaction was detected by gas chromatography.

[0093] Catalyst activity evaluation results: The conversion rate of cyclohexanone was 75.35%, and the selectivity for cyclohexanone oxime was 88.57%.

[0094] Comparative Example 2: The preparation method of Au-Pd / TS-1 nanosheets is the same as that in Example 1, except that 0.075 g of catalyst and 13.4 g of... 0.243 g (28) Replace with 0 g catalyst, 0 g 0 g (28) ), will be at 800 The reaction at 80 ℃ for 3 h was replaced by a reaction at a rotation speed of 0. The reaction was carried out at 60 °C for 0 h. The steps included are as follows: Preparation of TS-1 nanosheets: Following the formula: tetraethyl orthosilicate: tetrabutyl titanate: tetrapropylammonium hydroxide: The molar ratio of urea is 1: : : : First, 20.336 g of tetrapropylammonium hydroxide solution (25 g) was added. Mix 26.148 g of deionized water and stir for 30 min. Add 20.833 g of tetraethyl orthosilicate, stir for 2 h, and then add 3 g of urea. In another beaker, add 15.3 g of isopropanol, and add 1.122 g of tetrabutyl titanate dropwise while stirring. After adding the liquid from the second beaker to the first beaker, heat the Ti-containing solution at 80 °C to evaporate the alcohol. Finally, place the final solution in a hydrothermal reactor with a polytetrafluoroethylene liner and crystallize at 170 °C for three days. Wash the synthesized product with deionized water until the filtrate is neutral, dry at 60 °C overnight, and calcine at 550 °C for 6 h.

[0095] First, 0.014 g of palladium acetate was dissolved in a mixed solution of 10 mL ethanol and 10 mL acetonitrile. After complete dissolution, 2 g of TS-1 nanosheets were added, and the mixture was stirred at room temperature for 1 h. Then, the temperature was raised to 85 °C to evaporate the ethanol and acetonitrile mixture to dryness. The evaporated sample was then redispersed in 60 mL of... 0.013 g of tetrachloroauric acid trihydrate was added to the mixture, and after stirring at room temperature for 1 h, the temperature was raised to 85 °C and held for 16 h. The resulting sample was ground, calcined in air at 400 °C for 3 h, and then reduced at 400 °C for 3 h in a hydrogen atmosphere. The solid was then removed to obtain the catalyst.

[0096] Add 0.196 g of cyclohexanone to a 100 mL polytetrafluoroethylene liner, place it in a high-pressure reactor, and first use... The reactor was purged three times to remove all internal air, and then filled with... Content of 21% The mixed gas pressure is 1.3 MPa, then it is charged. Content of 5% The mixed gas increases the gas pressure inside the reactor to 4.0 MPa at a rotation speed of 0. The reaction was carried out at 60°C for 0 h. After cooling to room temperature in an ice-water bath, 6 g of ethanol and 0.15 g of diethylene glycol monoethyl ether were added, and the catalyst was removed by centrifugation. Diethylene glycol monoethyl ether was used as an internal standard in the internal standard method, and the reaction was detected by gas chromatography.

[0097] Catalyst activity evaluation results: The conversion rate of cyclohexanone was 0%, and the selectivity for cyclohexanone oxime was 0%.

[0098] Table 1 Catalyst Activities of Each Example and Comparative Example

[0099] Test Example 1: Test steps: Without adding cyclohexanone or ammonia, 0.01 g of catalyst and a mixed solvent consisting of 2.9 g of deionized water and 5.6 g of methanol were added to a 100 mL high-pressure reactor. The reactor was then charged with 21% [amount missing]. Mix the gas to 1.3 MPa, then add 5% more. The mixed gas increased the pressure inside the reactor to 4.0 MPa. The reaction was carried out at 2 °C and 800 r / min for 0.5 h. The amount of hydrogen peroxide generated in situ in the reaction solution was analyzed using iodometric titration. The measured amount of H₂O₂ produced was 45.27 mol. H2O2 ·kg cat -1 ·h -1 If not filled and Therefore, the amount of H2O2 produced is 0 mol. H2O2 ·kg cat -1 ·h -1 .

[0100] Test results show that this supported bifunctional catalyst achieves the coupling of the direct synthesis of hydrogen peroxide from hydrogen and oxygen with the amination and oximation of cyclohexanone. Validation data confirm that without charging... In the absence of Generate, and Catalyst metal sites can generate The combination of metal loading on TiO2 and mixing with TS-1 nanosheets in Example 9, which resulted in the consumption of cyclohexanone and the formation of cyclohexanone oxime, proves that the in-situ generation... Molecules can diffuse into the TS-1 nanosheet carrier The active site participates in the ammonoximation reaction to synthesize cyclohexanone oxime, confirming that the multifunctional TS-1 nanosheet catalyst can achieve the coupling of in-situ hydrogen peroxide synthesis and cyclohexanone ammonoximation reaction.

[0101] Test Example 2: Test steps: For cycle stability testing, the solid catalyst after reaction was recovered by centrifugation, washed sequentially with deionized water and anhydrous ethanol, and dried overnight at 60 °C. The dried catalyst was then added back into the next batch of reaction in the same proportion, and the test was repeated 5 times (test groups 1-5). The changes in cyclohexanone conversion and cyclohexanone oxime selectivity for each batch were recorded.

[0102] in conclusion: Table 2 Results of catalyst in-situ reaction performance and cycle stability tests

[0103] The test results show that after five cycles, the cyclohexanone conversion and cyclohexanone oxime selectivity of the catalyst remain at a high level, indicating that the catalyst has strong cycle stability.

[0104] The advantages of this technical solution are mainly reflected in the following aspects: Optimized diffusion performance: The support has a short b-axis, which shortens the diffusion path of reactant and product molecules in the pores and improves the utilization rate of active sites.

[0105] Improved framework stability: The hydrolysis rates of titanium and silicon sources were regulated during the synthesis of urea to ensure that titanium species could effectively enter the molecular sieve framework, thereby enhancing the hydrothermal and mechanical stability of the catalyst.

[0106] Process cost control: The in-situ generation mode avoids the transportation, storage and dilution process of pre-produced hydrogen peroxide in the traditional liquid phase method, reducing energy consumption and safety protection expenses.

[0107] Environmental friendliness: This process does not require the addition of stabilizers such as acids or halogens, reducing the risk of corrosion to industrial equipment and pollution to the environment.

[0108] Active site dispersion: The metal particles prepared by the impregnation method have small particle size and uniform distribution, and can still maintain high catalytic activity after 5 cycles, demonstrating good recycling performance.

[0109] Test Example 3: Experimental steps: The supported catalyst was added to a 100 mL polytetrafluoroethylene-lined high-pressure reactor, with the catalyst dosage adjusted from 0 to 0.1 g. 0.196 g of cyclohexanone was added to the reactor, followed by a solvent system consisting of deionized water (0 to 13.4 g) and tert-butanol (0 to 13.4 g), as required by each embodiment. Then, 0 to 0.268 g of ammonia solution with a mass fraction of 28 wt% was added. The reactor was purged three times with nitrogen to remove all internal air. First, an oxygen / nitrogen mixture with an oxygen content of 21% was introduced to a pressure of 1.3 MPa, followed by a hydrogen / nitrogen mixture with a hydrogen content of 5% to increase the pressure to 4.0 MPa. The reaction was carried out at a rotation speed of 0 to 1200 r / min and a temperature of 60 to 90 °C for 0 to 4 h. After the reaction was stopped, the reactor was cooled to room temperature using an ice-water bath. 6 g of ethanol and 0.15 g of diethylene glycol monoethyl ether were added to the system as internal standards. The catalyst solid was removed by centrifugation, and the supernatant was extracted. The concentrations of the components were determined by gas chromatography combined with the internal standard method, and the conversion rate of cyclohexanone and the selectivity of cyclohexanone oxime were calculated.

[0110] in conclusion: Table 3. Catalytic performance evaluation test results for each embodiment and comparative example.

[0111] Test data show that the morphology and structure of the catalyst, the ratio of active components, and the solvent system have a significant impact on the performance of the in-situ hydroxycyclohexanone amination reaction.

[0112] The morphology of the support determines the diffusion efficiency of molecules. Comparing Example 1 and Comparative Example 1, it can be seen that the conversion rate and selectivity of TS-1 nanosheets are higher than those of ordinary TS-1 at the same loading. This is because the growth of the two-dimensional sheet structure along the b-axis is restricted, which shortens the diffusion path of cyclohexanone and cyclohexanone oxime in the microporous channels, thereby increasing the utilization rate of the active sites of the framework titanium.

[0113] Urea plays a crucial regulatory role in the synthesis. It not only acts as a morphology-directing agent to guide the anisotropic growth of TS-1, but also regulates the hydrolysis rate of titanium and silicon esters, promoting the incorporation of more Ti into the framework and forming Ti. 4+ Site. Example 2 used an isopropanol-free synthetic support and adjusted the Ti / Si ratio, achieving a maximum conversion rate of 98.10% and a selectivity of 100.00%.

[0114] The Au-Pd bimetallic component exhibited synergistic catalytic activity. Data from Examples 3 and 4 confirmed that the catalytic performance of the monometallic support was significantly lower than that of the bimetallic support. The metal component formed uniformly dispersed and fine-particle-size alloy clusters in the channels and surface of the support, which facilitated the efficient generation of hydrogen peroxide from hydrogen and oxygen and enabled it to rapidly diffuse to adjacent titanium sites to participate in the ammonium oxime reaction.

[0115] The in-situ process eliminates the need for pre-prepared hydrogen peroxide in traditional liquid-phase methods. This not only avoids the energy waste and safety risks associated with the transportation, storage, and dilution of high-concentration hydrogen peroxide, but also prevents the corrosion of equipment caused by the addition of acids or halogens to maintain the stability of hydrogen peroxide.

[0116] The solvent system plays a supporting role in regulating the reaction activity. Comparing Example 1 and Example 11, it is evident that the mixed solvent system with added tert-butanol significantly improves the reaction selectivity compared to the pure water system. The combined effect of the mixed solvent and the diffusion advantages of the two-dimensional sheet-like support achieves high atom utilization and high product yield in the reaction process.

[0117] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. Multifunctional titanium-silicon molecular sieve TS-1 nanosheets, characterized in that, Made from raw materials comprising the following parts by weight: 2 parts TS-1 nanosheet carrier; Gold source precursor 0-0.026 parts; Palladium source precursor 0-0.028 parts.

2. The multifunctional titanium-silicon molecular sieve TS-1 nanosheets according to claim 1, characterized in that, The gold source precursor is tetrachloroauric acid trihydrate; the palladium source precursor is selected from one or two of palladium acetate and palladium chloride; the nanosheets are also loaded with one or more metal elements selected from Pt, Sn, Zn and Ni.

3. The multifunctional titanium-silicon molecular sieve TS-1 nanosheets according to claim 1, characterized in that, The nanosheets can also be used in the following ways: loading the gold source precursor and / or palladium source precursor onto TiO2 to form a supported TiO2, and then physically mixing the supported TiO2 with the TS-1 nanosheet carrier.

4. The multifunctional titanium-silicon molecular sieve TS-1 nanosheets according to claim 1, characterized in that, The TS-1 nanosheet carrier is made from raw materials containing the following molar ratios: tetraethyl orthosilicate 1; tetrabutyl titanate 0.01-0.06; tetrapropylammonium hydroxide 0.25; water 23; and urea 0.15-0.

7.

5. The multifunctional titanium-silicon molecular sieve TS-1 nanosheets according to claim 1, characterized in that, The TS-1 nanosheet carrier is grown in a restricted manner along the b-axis to form a two-dimensional sheet structure.

6. The method for preparing multifunctional titanium-silicon molecular sieve TS-1 nanosheets according to any one of claims 1-5, characterized in that, Includes the following steps: S1: Mix tetrapropylammonium hydroxide solution, deionized water and tetraethyl orthosilicate to obtain a mixed solution, then add urea and continue stirring; S2: Add a titanium source to the solution obtained in S1 to obtain a titanium-containing mixture; S3: Heat the titanium-containing mixture to evaporate the alcohol; S4: The product obtained in S3 was subjected to hydrothermal crystallization, followed by washing, drying and calcination to obtain TS-1 nanosheet carrier; S5: The TS-1 nanosheet carrier is immersed in a solvent containing a gold source precursor and / or a palladium source precursor; S6: The product obtained in S5 is dried, ground and activated to obtain the multifunctional titanium-silicon molecular sieve TS-1 nanosheets.

7. The multifunctional titanium-silicon molecular sieve TS-1 nanosheets according to claim 6, its preparation method and application, characterized in that, In step S1, the mass fraction of the tetrapropylammonium hydroxide solution is 25 wt%, and the amount of urea added is 0.901-4.205 g; in step S2, the titanium source is tetrabutyl titanate, which is pre-dissolved in 0-17 g isopropanol before being added.

8. The multifunctional titanium-silicon molecular sieve TS-1 nanosheets according to claim 6, its preparation method and application, characterized in that, In S4, the hydrothermal crystallization conditions are crystallization at 170 °C for 3 days; the calcination conditions are calcination at 550 °C for 6 hours.

9. The multifunctional titanium-silicon molecular sieve TS-1 nanosheets according to claim 6, its preparation method and application, characterized in that, In step S5, the solvent is selected from one or more of water, ethanol, acetonitrile, and acetone. In step S6, the activation treatment is performed at 400 °C for 3 h in one or more atmospheres selected from nitrogen, air, and hydrogen.

10. The application of the multifunctional titanium-silicon molecular sieve TS-1 nanosheets according to any one of claims 1-5 in the in-situ hydroxycyclohexanone ammoniumization reaction, characterized in that, In the same reaction system, the nanosheets catalyze the in-situ generation of hydrogen peroxide from H2 and O2. The generated hydrogen peroxide directly participates in the ammonoximation reaction of cyclohexanone and ammonia to generate cyclohexanone oxime. The reaction conditions include the following mass ratios: cyclohexanone 1, catalyst 0-0.52, water 0-68.4, t-BuOH 0-68.4, NH3·H2O (28wt%) 0-1.37, total gas pressure 4 MPa, containing 6.8% O2, 3.4% H2, and 89.8% N2, and the reaction is carried out at a rotation speed of 0-1200 r / min and a temperature of 60-90 ℃ for 0-4 h.

Images