Composite catalytic material for photocatalytic cyclohexane oxidation reaction as well as preparation method and application of composite catalytic material
By preparing C-WO3-WO3-x composite catalytic materials, the electronic structure and light absorption capacity of WO3 were improved by utilizing oxygen vacancies, thus solving the efficiency and selectivity problems of WO3 photocatalysts in the cyclohexane oxidation reaction and achieving a highly efficient catalytic effect.
Patent Information
- Application Number
- CN202511246916.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-02
- Publication Date
- 2025-12-30
AI Technical Summary
Existing WO3 photocatalysts exhibit high photogenerated holes and electron recombination rates and low light absorption range in the cyclohexane oxidation reaction, resulting in low catalytic efficiency and poor selectivity.
By preparing C-WO3-WO3-x composite catalytic materials, the electronic structure of the catalytic materials is altered by utilizing oxygen vacancies, thereby increasing light absorption capacity and providing additional active sites in the reaction, thus enhancing the photocatalytic activity and selectivity of the catalyst.
It improved the efficiency and selectivity of the cyclohexane oxidation reaction, reduced the degradation rate of the catalyst, and maintained good catalytic performance.
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Figure CN121222418A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application discloses a composite catalytic material, in particular, a C-WO3-WO 3-x The application discloses a composite catalytic material, a preparation method and application thereof, and belongs to the technical field of catalysts. BACKGROUND
[0002] In the field of catalytic engineering and modern chemical processes, the selective oxidation of cyclohexane to cyclohexanone and cyclohexanol (referred to as KA oil) is a great challenge. The inherent chemical stability of the C-H bond in cyclohexane requires harsh reaction conditions, which usually involve temperatures of 150-170℃ and pressures of about 10-20 standard atmospheres in an industrial environment. These conditions usually lead to the formation of unwanted by-products, thereby reducing the overall process selectivity and increasing operating costs. Therefore, achieving high selectivity while maintaining optimal conversion rate remains the primary goal in the field of research on catalytic oxidation of cyclohexane.
[0003] Semiconductor catalytic technology can solve the technical bottleneck of this reaction. WO3 is a traditional photocatalytic material, but its light absorption range is below 450 nm, the light utilization rate is extremely low, and because of the high recombination rate of photo-generated holes and electrons formed in the oxidation process of WO3, it is difficult to apply it to catalytic reactions. SUMMARY
[0004] To overcome the above-mentioned deficiencies and solve the technical problems of WO3 as a photocatalyst in the reaction, the application provides a composite catalytic material for photocatalytic oxidation of cyclohexane, which reduces the recombination rate of photo-generated holes and electrons in the reaction of WO3, improves the light absorption band of WO3, and improves the conversion of cyclohexane oxidation reaction.
[0005] The second object of the application is to provide a preparation method of a composite catalytic material for photocatalytic oxidation of cyclohexane.
[0006] The third object of the application is to provide a method for catalyzing cyclohexane oxidation reaction by the above-mentioned composite photocatalytic material, which has strong catalytic activity, high efficiency and high selectivity in cyclohexane oxidation reaction.
[0007] To this end, the first technical solution provided by the application is as follows:
[0008] A preparation method of a composite catalytic material for photocatalytic oxidation of cyclohexane, comprising the following steps in sequence:
[0009] S1. Preparation of WO3 nanorods:
[0010] The tungsten source and sodium salt are added into ultrapure water, the pH of the system is adjusted to be acidic, and the hydrothermal reaction is carried out at 160-200℃ for 20-24h; the reaction product is washed and dried to obtain WO3nanorods;
[0011] The molar ratio of the sodium tungstate dihydrate and sodium chloride is 1:1.5-1:2.
[0012] S2. Preparation of WO3-WO 3-x
[0013] The WO3nanorods prepared in step 1) are added into an ethanol solution and ultrasonically dispersed, then centrifuged; the WO3nanorods after centrifugation are added into a solvent and a tungsten source, and ultrasonically dispersed uniformly, and then the hydrothermal reaction is carried out at 150-170℃ for 12-36h; the reaction product is washed and dried to obtain WO3-WO 3-x :
[0014] S3. Preparation of WO3-WO 3-x -Ov
[0015] The WO3-WO 3-x prepared in S2 is placed into a tube furnace and calcined at 250-300℃ for 1h under an argon atmosphere; the deep blue product after calcination is recorded as WO3-WO 3-x -Ov.
[0016] The molar ratio of the tungsten hexachloride and the WO3nanorods is 1:5-1:20.
[0017] Further, the preparation method of the composite catalytic material for photocatalytic oxidation of cyclohexane described above further comprises:
[0018] S4. Preparation of C-WO3-WO 3-x
[0019] The WO3-WO 3-x -Ov prepared in S3 is placed into a tube furnace and calcined at 250-300℃ for 1-2h under an argon atmosphere; the product after calcination at 250-300℃ is placed into a muffle furnace and calcined at 250-300℃ for 0.5-2h under an air atmosphere to obtain C-WO3-WO 3-x .
[0020] Further, the preparation method of the composite catalytic material for photocatalytic oxidation of cyclohexane described above, the preparation method of the composite catalytic material for photocatalytic oxidation of cyclohexane described above, the pH of the system adjusted in S1 is adjusted to be acidic by using hydrochloric acid to adjust the pH to 2.
[0021] Further, the preparation method of the composite catalytic material for photocatalytic oxidation of cyclohexane described above, the preparation method of the composite catalytic material for photocatalytic oxidation of cyclohexane described above, the tungsten source in S1 is sodium tungstate dihydrate; and the sodium salt is sodium chloride.
[0022] Further, the preparation method of the composite catalytic material for photocatalytic cyclohexane oxidation reaction, the tungsten source in S2 is tungsten hexachloride.
[0023] Further, the preparation method of the composite catalytic material for photocatalytic cyclohexane oxidation reaction, the ethanol solution in S2 is an ethanol aqueous solution with an ethanol volume fraction of 90%; and the solvent is anhydrous ethanol.
[0024] The application further provides a composite catalytic material for photocatalytic cyclohexane oxidation reaction, which is prepared by the above preparation method. 3-x -Ov catalyst.
[0025] The application further provides a composite catalytic material for photocatalytic cyclohexane oxidation reaction, which is prepared by the above preparation method. 3-x Catalyst.
[0026] The application further provides an application of the above composite catalytic material as a catalyst for photocatalytic cyclohexane oxidation reaction.
[0027] The application further provides a method for photocatalytic cyclohexane oxidation reaction, which comprises the following steps in sequence:
[0028] 1) A composite photo-thermal catalytic material is weighed and dissolved in cyclohexane and a solvent to obtain a reaction solution;
[0029] 2) The solution prepared in step 1) is poured into a photo-thermal reactor, the reactor is sealed, and 1-2 MPa of dry air is filled;
[0030] 3) The reaction is carried out at 100-150 DEG C under the irradiation of a xenon lamp for 6-10 h;
[0031] 4) After the reaction is completed, the reactor is cooled to room temperature, the reacted solution is taken out, and gas chromatography analysis is performed;
[0032] The ratio of the composite photo-thermal catalytic material to cyclohexane is 1.5-2.5 mg: 1 mL.
[0033] Compared with the prior art, the application has the following beneficial effects:
[0034] 1. The technical scheme provided by the application utilizes oxygen vacancies to change the electronic structure of the catalytic material, reduces the recombination rate of photo-generated holes and electrons of WO3 during the reaction, increases the light absorption capacity of the material, and improves the photocatalytic activity, thereby improving the efficiency of catalytic cyclohexane oxidation. 3-x -Ov composite catalytic material, and especially the C-WO3-WO 3-xThe oxygen vacancies of the composite catalytic material provide additional active sites for the reaction as the center of adsorption and reaction, thereby improving the performance of the catalyst in the reaction process.
[0035] 2. The technical solution provided by the present application optimizes the durability of the catalyst material by introducing oxygen vacancies, so that WO3-WO 3-x -Ov composite catalytic material, especially C-WO3-WO 3-x The composite catalytic material maintains good performance in long-time reaction and reduces the degradation rate of the catalyst. BRIEF DESCRIPTION OF DRAWINGS
[0036] Figure 1 The XRD patterns of WO 3-x -Ov and C-WO 3-x provided for Comparative Example 2 and Comparative Example 3;
[0037] Figure 2 The XRD patterns of WO3, WO 3-x -Ov and WO3-WO 3-x -Ov-10 composite photocatalytic material provided for Example 2, Comparative Example 1 and Comparative Example 2;
[0038] Figure 3 The XRD patterns of WO 3-x -Ov, C-WO 3-x , WO3-WO 3-x -Ov-10 and C-WO3-WO 3-x -10 composite photocatalytic material provided for Example 5, Example 2, Comparative Example 2 and Comparative Example 3;
[0039] Figure 4 The XRD patterns of WO 3-x -Ov and WO3-WO 3-x -Ov-10 composite photocatalytic material provided for Example and Comparative Example 2;
[0040] Figure 5 The EPR·hydroxyl radical test patterns of WO3, C-WO3, WO 3-x , C-WO 3-x , WO3-WO 3-x -Ov-10 and C-WO3-WO 3-x -10 composite photocatalytic material provided for Example 2, Experimental Example 5, Comparative Example 1, Comparative Example 2 and Comparative Example 3;
[0041] Figure 6 The EPR·hydroxyl radical test patterns of WO3, C-WO3, WO 3-x , C-WO 3-x, WO3-WO 3-x -Ov-10 and C-WO3-WO 3-x EPR·superoxide radical test diagram of the 10 composite photo-thermal catalytic material. DETAILED DESCRIPTION
[0042] The claims of the present application will be further described in detail below in the manner of specific embodiments, but do not constitute any limitation on the present application, and any limited number of modifications made by anyone within the scope of the claims of the present application is still within the scope of the claims of the present application.
[0043] Unless otherwise specified, the reagents, methods and equipment used in the present application are conventional reagents, methods and equipment in the art, and the default temperature is room temperature.
[0044] Example 1
[0045] The present embodiment provides a WO3-WO 3-x -Ov-5 composite photo-thermal catalytic material, which is prepared by the following method:
[0046] 1) Synthesis of WO3 nanorods
[0047] 2.5 mmol of sodium tungstate dihydrate and 5 mmol of sodium chloride were added to 19 mL of ultrapure water, and ultrasonic dispersion was carried out for 20 min at 33 KHz to a transparent solution. Then, the pH of the solution was adjusted to 2 by adding 3M HCl dropwise, and the solution was reacted at 180℃ in a polytetrafluoroethylene reaction kettle for 24 hours. After cooling to room temperature, it was washed once with water and then several times with anhydrous ethanol, and dried at 60℃ under a vacuum of -0.1 MPa for 12 h to obtain WO3 nanorods.
[0048] 2) Synthesis of WO3-WO 3-x -5
[0049] 30 mg of WO3 nanorods from step 1) were added to a 90% volume fraction of an aqueous ethanol solution and ultrasonicated for 40 min, and then the ultrasonicated sample was placed in a centrifuge for centrifugation. Anhydrous ethanol was poured into the centrifuged WO3 nanorods, and then 0.38 mmol of tungsten hexachloride was added thereto. The solution was then ultrasonically dispersed uniformly, and a hydrothermal reaction was carried out at 160℃ for 24 hours. After cooling to room temperature, it was washed 2-3 times with deionized water and anhydrous ethanol, and dried at 60℃ under a vacuum of -0.1 MPa for 12 h to obtain a WO3-WO 3-x -5 composite photo-thermal catalytic material.
[0050] 3) Synthesis of WO3-WO 3-x -Ov-5
[0051] WO3-WO3-x -5 was placed in a tube furnace and calcined at 300°C for 1 hour under an argon atmosphere. The dark blue product after calcination was designated as WO3-WO. 3-x -Ov-5.
[0052] Example 2
[0053] This embodiment provides a WO3-WO 3-x -Ov-10 composite photothermal catalytic material, which is prepared sequentially by the following methods:
[0054] 1) Synthesis of WO3 nanorods
[0055] 2.5 mmol of sodium tungstate dihydrate and 5 mmol of sodium chloride were added to 19 mL of ultrapure water and ultrasonically dispersed at 33 kHz for 20 min until a clear solution was obtained. Then, 3M HCl was added dropwise to adjust the pH of the solution to 2. The reaction was carried out in a polytetrafluoroethylene reactor at 180 °C for 24 h. After cooling to room temperature, the solution was washed once with water and then several times with anhydrous ethanol. The solution was then dried under vacuum at 60 °C and -0.1 MPa for 12 h to obtain WO3 nanorods.
[0056] 2)WO3-WO 3-x -10 synthesis
[0057] 30 mg of the WO3 nanorods from step 1) were added to a 90% ethanol aqueous solution and sonicated for 40 min. The sonicated sample was then centrifuged. Anhydrous ethanol was added to the centrifuged WO3 nanorods, followed by 0.76 mmol of tungsten hexachloride. The solution was then sonicated to disperse the nanorods evenly and subjected to a hydrothermal reaction at 160 °C for 24 h. After cooling to room temperature, the nanorods were washed 2-3 times with deionized water and anhydrous ethanol, and then dried under vacuum at 60 °C and -0.1 MPa for 12 h to obtain WO3-WO 3-x -10 composite photothermal catalytic material.
[0058] 3)WO3-WO 3-x Synthesis of -Ov-10
[0059] The WO3-WO3 was obtained by vacuum drying at 60℃ and -0.1MPa for 12 hours. 3-x -10 was placed in a tube furnace and calcined at 300°C for 1 hour under an argon atmosphere. The dark blue product after calcination was designated as WO3-WO. 3-x -Ov-10.
[0060] Example 3
[0061] This embodiment provides a WO3-WO 3-x -Ov-20 composite photothermal catalytic material, which is prepared sequentially by the following methods:
[0062] 1) Synthesis of WO3 nanorods
[0063] 2.5 mmol of sodium tungstate dihydrate and 5 mmol of sodium chloride were added to 19 mL of ultrapure water and ultrasonically dispersed at 33 kHz for 20 min until a clear solution was obtained. Then, 3M HCl was added dropwise to adjust the pH of the solution to 2. The reaction was carried out in a polytetrafluoroethylene reactor at 180 °C for 24 h. After cooling to room temperature, the solution was washed once with water and then several times with anhydrous ethanol. The solution was then dried under vacuum at 60 °C and -0.1 MPa for 12 h to obtain WO3 nanorods.
[0064] 2)WO3-WO 3-x -20 synthesis
[0065] 30 mg of the WO3 nanorods from step 1) were added to a 90% ethanol aqueous solution and sonicated for 40 min. The sonicated sample was then centrifuged. Anhydrous ethanol was added to the centrifuged WO3 nanorods, followed by 1.52 mmol of tungsten hexachloride. The solution was then sonicated to disperse the nanorods evenly and subjected to a hydrothermal reaction at 160 °C for 24 hours. After cooling to room temperature, the nanorods were washed 2-3 times with deionized water and anhydrous ethanol, and then dried under vacuum at 60 °C and -0.1 MPa for 12 h. The resulting product was denoted as WO3-WO. 3-x -20 composite photothermal catalytic material.
[0066] 3)WO3-WO 3-x Synthesis of -Ov-20
[0067] The WO3-WO3 was obtained by vacuum drying at 60℃ and -0.1MPa for 12 hours. 3-x -20 was placed in a tube furnace and calcined at 300°C for 1 hour under an argon atmosphere. The dark blue product after calcination was designated as WO3-WO. 3-x -Ov-20.
[0068] Example 4
[0069] This embodiment provides a C-WO3-WO 3-x The composite photothermal catalytic material is prepared sequentially by the following methods:
[0070] 1) Synthesis of WO3 nanorods
[0071] 2.5 mmol of sodium tungstate dihydrate and 5 mmol of sodium chloride were added to 19 mL of ultrapure water and ultrasonically dispersed at 33 kHz for 20 min until a clear solution was obtained. Then, 3M HCl was added dropwise to adjust the pH of the solution to 2. The reaction was carried out in a polytetrafluoroethylene reactor at 180 °C for 24 h. After cooling to room temperature, the solution was washed once with water and then several times with anhydrous ethanol. The solution was then dried under vacuum at 60 °C and -0.1 MPa for 12 h to obtain WO3 nanorods.
[0072] 2)WO3-WO 3-x -10 synthesis
[0073] 30 mg of the WO3 nanorods from step 1) were added to a 90% ethanol aqueous solution and sonicated for 40 min. The sonicated sample was then centrifuged. Anhydrous ethanol was added to the centrifuged WO3 nanorods, followed by 0.76 mmol of tungsten hexachloride. The solution was then sonicated to disperse the nanorods evenly and subjected to a hydrothermal reaction at 160 °C for 24 hours. After cooling to room temperature, the nanorods were washed 2-3 times with deionized water and anhydrous ethanol, and then dried under vacuum at 60 °C and -0.1 MPa for 12 h. The resulting product was denoted as WO3-WO. 3-x -10 composite photothermal catalytic material.
[0074] 3) C-WO3-WO 3-x -10 synthesis
[0075] The WO3-WO3 was obtained by vacuum drying at 60℃ and -0.1MPa for 12 hours. 3-x -10 is placed in a tube furnace and calcined at 300°C for 1 hour under an argon atmosphere. The dark blue product after calcination is WO3-WO. 3-x -Ov-10, then put WO3-WO 3-x -Ov-10 was placed in a muffle furnace and calcined at 300°C for 1 hour in air atmosphere. The resulting product was denoted as C-WO3-WO. 3-x -10.
[0076] Example 5
[0077] This embodiment provides a C-WO3-WO 3-x -5 composite photothermal catalytic material, which is prepared sequentially by the following methods:
[0078] 1) Synthesis of WO3 nanorods
[0079] 2.5 mmol of sodium tungstate dihydrate and 5 mmol of sodium chloride were added to 19 mL of ultrapure water and ultrasonically dispersed at 33 kHz for 20 min until a clear solution was obtained. Then, 3M HCl was added dropwise to adjust the pH of the solution to 2. The reaction was carried out in a polytetrafluoroethylene reactor at 180 °C for 24 h. After cooling to room temperature, the solution was washed once with water and then several times with anhydrous ethanol. The solution was then dried under vacuum at 60 °C and -0.1 MPa for 12 h to obtain WO3 nanorods.
[0080] 2)WO3-WO 3-x -5 synthesis
[0081] 30 mg of the WO3 nanorods from step 1) were added to a 90% ethanol aqueous solution and sonicated for 40 min. The sonicated sample was then centrifuged. Anhydrous ethanol was added to the centrifuged WO3 nanorods, followed by 0.38 mmol of tungsten hexachloride. The solution was then sonicated to disperse the nanorods evenly and subjected to a hydrothermal reaction at 160 °C for 24 h. After cooling to room temperature, the nanorods were washed 2-3 times with deionized water and anhydrous ethanol, and then dried under vacuum at 60 °C and -0.1 MPa for 12 h to obtain WO3-WO 3-x -5 composite photothermal catalytic material.
[0082] 3)WO3-WO 3-x Synthesis of -Ov-5
[0083] The WO3-WO3 was obtained by vacuum drying at 60℃ and -0.1MPa for 12 hours. 3-x -5 was placed in a tube furnace and calcined at 300°C for 1 hour under an argon atmosphere. The dark blue product after calcination was designated as WO3-WO. 3-x -Ov-5, then put WO3-WO 3-x -Ov-5 was placed in a muffle furnace and calcined at 300°C for 1 hour in air atmosphere. The resulting product was denoted as C-WO3-WO. 3-x -5.
[0084] Example 6
[0085] This embodiment provides a C-WO3-WO 3-x -20 composite photothermal catalytic material is prepared sequentially by the following methods:
[0086] 1) Synthesis of WO3 nanorods
[0087] 2.5 mmol of sodium tungstate dihydrate and 5 mmol of sodium chloride were added to 19 mL of ultrapure water and ultrasonically dispersed at 33 kHz for 20 min until a clear solution was obtained. Then, 3M HCl was added dropwise to adjust the pH of the solution to 2. The reaction was carried out in a polytetrafluoroethylene reactor at 180 °C for 24 h. After cooling to room temperature, the solution was washed once with water and then several times with anhydrous ethanol. The solution was then dried under vacuum at 60 °C and -0.1 MPa for 12 h to obtain WO3 nanorods.
[0088] 2)WO3-WO 3-x -20 synthesis
[0089] 30 mg of the WO3 nanorods from step 1) were added to a 90% ethanol aqueous solution and sonicated for 40 min. The sonicated sample was then centrifuged. Anhydrous ethanol was added to the centrifuged WO3 nanorods, followed by 1.52 mmol of tungsten hexachloride. The solution was then sonicated to disperse the nanorods evenly and subjected to a hydrothermal reaction at 160 °C for 24 hours. After cooling to room temperature, the nanorods were washed 2-3 times with deionized water and anhydrous ethanol, and then dried under vacuum at 60 °C and -0.1 MPa for 12 h. The resulting product was denoted as WO3-WO. 3-x -20 composite photothermal catalytic material.
[0090] 4)WO3-WO 3-x Synthesis of -Ov-20
[0091] The WO3-WO3 was obtained by vacuum drying at 60℃ and -0.1MPa for 12 hours. 3-x -20 was placed in a tube furnace and calcined at 300°C for 1 hour under an argon atmosphere. The dark blue product after calcination was designated as WO3-WO. 3-x -Ov-20, then put WO3-WO 3-x -Ov-20 was placed in a muffle furnace and calcined at 300°C for 1 hour in air atmosphere. The resulting product was denoted as C-WO3-WO. 3-x -20.
[0092] It should be noted that WO 3-x x represents the number of oxygen vacancies, where X is an indeterminate number. Ov represents an O defect (oxygen vacancy).
[0093] Comparative Example 1
[0094] Commercially available WO3.
[0095] Comparative Example 2
[0096] This comparative example provides a WO 3-x-Ov, which is prepared by the following method: 1.5 mmol of tungsten hexachloride is added to 20 ml of anhydrous ethanol, and then the solution is ultrasonically dispersed for 20 min until homogeneous using an ultrasonic machine at a frequency of 33 kHz. A hydrothermal reaction is then carried out at 160 °C for 24 h. The reaction product is eluted and dried under vacuum at 60 °C and -0.1 MPa for 12 h. WO 3-x The WO3-x obtained by vacuum drying at 60℃ and -0.1MPa for 12 hours was placed in a tube furnace and calcined at 300℃ for 1 hour under an argon atmosphere. The dark blue product after calcination is WO3. 3-x -Ov.
[0097] Comparative Example 3
[0098] This comparative example provides a C-WO 3-x It was prepared by the following method: 1.5 mmol of tungsten hexachloride was weighed and added to 20 ml of anhydrous ethanol. The solution was then ultrasonically dispersed for 20 min until homogeneous using a 33 kHz ultrasonicator, and subjected to a hydrothermal reaction at 160 °C for 24 h. The reaction product was eluted and dried under vacuum at 60 °C and -0.1 MPa for 12 h. WO3 3-x The WO3-x obtained by vacuum drying at 60℃ and -0.1MPa for 12 hours was placed in a tube furnace and calcined at 300℃ for 1 hour under an argon atmosphere. The dark blue product after calcination is WO3. 3-x -Ov, then put WO 3-x -Ov was placed in a muffle furnace and calcined at 300°C for 1 hour in air atmosphere to obtain C-WO. 3-x .
[0099] To verify the performance of the catalyst provided in this application, the following are the catalyst performance testing experiments provided in Examples 1-4 and Comparative Examples 1-3 of this application.
[0100] Detection Example 1
[0101] This test example 1 applies to the WO3-WO provided in Example 1. 3-x -Ov-5 composite photothermal catalytic material was tested.
[0102] 1. Detection of superoxide free radicals
[0103] Weigh 20 mg of WO3-WO prepared in Example 1 3-x The -Ov-5 composite photothermal catalytic material was dissolved in 2 mL of cyclohexane to obtain the test solution. The test solution was irradiated with light for 2 min, and the supernatant was used for EPR testing; the results are shown in [reference needed]. Figure 6 d.
[0104] 2. Water is used to detect hydroxyl radicals.
[0105] Weigh 20 mg of WO3-WO prepared in Example 1 3-x The Ov-5 composite photothermal catalytic material was dissolved in 2 mL of water to obtain the test solution. The test solution was irradiated with light for 2 min, and the supernatant was used for EPR testing. See the results below. Figure 5 d.
[0106] 3. Oxygen vacancy detection
[0107] Weigh 5 mg of WO3-WO prepared in Example 1 3-x -Ov-5 composite photothermal catalytic material was used for oxygen vacancy detection at low temperature; results are available in [reference]. Figure 3 a.
[0108] Detection Example 2
[0109] This test example applies to the WO3-WO provided in Example 2. 3-x The Ov-10 composite photothermal catalytic material was tested using the same method as in test example 1.
[0110] Detection Example 3
[0111] This test example applies to the WO3-WO provided in Example 3. 3-x The Ov-20 composite photothermal catalytic material was tested using the same method as in test example 1.
[0112] Detection Example 4
[0113] This test example applies to the C-WO3-WO provided in Example 4. 3-x The -10 composite photothermal catalytic material was tested using the same method as in test example 1.
[0114] Comparative Detection Example 1
[0115] This test example tests the WO3 described in Comparative Example 1 using the same method as in Test Example 1.
[0116] Comparative test example 2
[0117] This comparative example test case compares the provided WO with Comparative Example 2. 3-x The testing method is the same as that used in test example 1.
[0118] Comparative test example 3
[0119] This comparative example test case uses the C-WO provided in Comparative Example 2. 3-x The testing method is the same as that used in test example 1.
[0120] To better understand this application, the experimental results of the embodiments are further analyzed and explained below with reference to the accompanying drawings.
[0121] Figure 1The WO provided in Comparative Examples 2 and 3 3-x -Ov and C-WO 3-x XRD patterns, WO 3-x -Ov is a standard monoclinic phase with a distinct characteristic peak of the (010) crystal plane at 23.14°. After calcination, the characteristic peak of the (010) crystal plane did not disappear. Meanwhile, the characteristic peak of the orthorhombic phase (200) appeared at 24.29° and the characteristic peak of the hexagonal phase (220) appeared at 50.35°.
[0122] Figure 2 WO3 and WO3 provided for Example 2, Comparative Example 1 and Comparative Example 2 3-x -Ov and WO3-WO 3-x -Oxygen vacancy testing of the Ov-10 composite photothermal catalytic material; the oxygen vacancy content of the three materials before and after illumination shows that the composite material WO3-WO 3-x -Ov-10 is always better than WO3 and WO 3-x The high oxygen vacancy content of -Ov indicates that the composite material WO3-WO is exposed to light. 3-x -Ov-10 can have more active sites participating in catalytic reactions.
[0123] Figure 3 The WO provided for Example 5, Example 2, Comparative Example 2 and Comparative Example 3 3-x -Ov、C-WO 3-x WO3-WO 3-x -Ov-10 and C-WO3-WO 3-x -10 composite photothermal catalytic material oxygen vacancy test; we can find that after calcination, C-WO 3-x and C-WO3-WO 3-x The oxygen vacancy content was higher than that of WO3. 3-x -Ov and WO3-WO 3-x The -Ov is low, which indicates that after calcination in a muffle furnace, oxygen vacancies on the catalyst surface capture oxygen from the air and recombine.
[0124] Figure 4 WO provided for Examples and Comparative Example 2 3-x -Ov and WO3-WO 3-x -Oxygen vacancy testing of the Ov-10 composite photothermal catalytic material: We can see that the oxygen vacancy content of the material under dark field is always lower than that under bright field. This is because the photothermal catalytic material absorbs energy under light, and electrons and holes separate, generating more oxygen vacancies, which increases the active sites of the catalyst, thereby improving the efficiency of photothermal synergistic catalytic cyclohexane oxidation reaction.
[0125] Figure 5WO3, C-WO3, and WO3 provided for Example 2, Experimental Example 5, Comparative Example 1, Comparative Example 2, and Comparative Example 3 3-x C-WO 3-x WO3-WO 3-x -Ov-10 and C-WO3-WO 3-x EPR·hydroxyl radical test of -10 composite photothermal catalytic material; by Figure 5 a) It can be seen that C-WO3-WO 3-x The content of hydroxyl radicals is much higher than that of C-WO3 and C-WO4. 3-x This is why the photothermal synergistic catalytic reaction of composite materials results in higher efficiency in the cyclohexane oxidation reaction. And through... Figure 5 b) and d) show that the C-WO3 produced after calcination in the muffle furnace 3-x and C-WO 3- WO 3-x They all have higher hydroxyl radical signals, combined Figure 2 Based on the oxygen vacancy test of WO3, we infer that although the surface oxygen vacancy of the material after muffle furnace calcination is reduced, the (010) phase and (200) phase of WO3 are more conducive to the generation of hydroxyl radicals due to the multiphase mixing.
[0126] Figure 6 WO3, C-WO3, and WO3 provided for Example 2, Experimental Example 5, Comparative Example 1, Comparative Example 2, and Comparative Example 3 3-x C-WO 3-x WO3-WO 3-x -Ov-10 and C-WO3-WO 3-x EPR·superoxide radical test of -10 composite photothermal catalytic material; by Figure 6 a) It can be seen that C-WO3-WO 3-x The content of superoxide radicals is much higher than that of C-WO3 and C-WO4. 3-x This demonstrates that the photothermal synergistic catalytic reaction of composite materials results in a higher efficiency for the oxidation of cyclohexane.
[0127] Application Example 1
[0128] This application example uses the WO3-WO provided in Example 1. 3-x The Ov-5 photothermal catalytic material catalyzes the photothermal catalytic reaction of cyclohexane, and the reaction process specifically includes the following steps:
[0129] 1) Weigh out 30mg of WO3-WO 3-x -Ov-5 photothermal catalyst material was dissolved in 15 mL of cyclohexane and 7.5 mL of acetonitrile;
[0130] 2) Pour the solution prepared in step 1) into the photothermal reactor, seal the reactor, and fill it with dry air at 1.5 MPa;
[0131] 3) The reaction was carried out at 120℃ under xenon lamp irradiation for 8 hours;
[0132] 4) After the reaction was completed, the reactor was cooled to room temperature. The solution after the reaction was taken out and the conversion rate was measured by gas chromatography to be 7.99% and the selectivity was 99.01%.
[0133] Application Example 2
[0134] The photothermal catalytic material provided in this application example catalyzes the photothermal catalytic reaction of cyclohexane. The reaction process and parameters are basically the same as in the previous example, the only difference being the use of the catalyst WO3-WO prepared in Example 2. 3-x -Ov-10 replaces the catalyst WO3-WO prepared in Example 1. 3-x -Ov-5.
[0135] Application Example 3
[0136] The photothermal catalytic material provided in this application example catalyzes the photothermal catalytic reaction of cyclohexane. The reaction process and parameters are basically the same as in the previous examples, the only difference being the use of the catalyst WO3-WO prepared in Example 3. 3-x -Ov-20 replaces the catalyst WO3-WO prepared in Example 1. 3-x -Ov-5.
[0137] Application Example 4
[0138] The photothermal catalytic material provided in this application example catalyzes the photothermal catalytic reaction of cyclohexane. The reaction process and parameters are basically the same as in the previous examples, the only difference being the use of the catalyst C-WO3-WO prepared in Example 4. 3-x -5 replaced the catalyst WO3-WO prepared in Example 1. 3-x -Ov-5.
[0139] Application Example 5
[0140] The photothermal catalytic material provided in this application example catalyzes the photothermal catalytic reaction of cyclohexane. The reaction process and parameters are basically the same as in the previous examples, the only difference being the use of the catalyst C-WO3-WO prepared in Example 4. 3-x -10 replaced the catalyst WO3-WO prepared in Example 1. 3-x -Ov-5.
[0141] Application Example 6
[0142] The photothermal catalytic material provided in this application example catalyzes the photothermal catalytic reaction of cyclohexane. The reaction process and parameters are basically the same as in the previous examples, the only difference being the use of the catalyst C-WO3-WO prepared in Example 4. 3-x -20 replaced the catalyst WO3-WO prepared in Example 1.3-x -Ov-5.
[0143] Comparative Application Example 1
[0144] The photothermal catalytic material provided in this comparative example catalyzes the photothermal catalytic reaction of cyclohexane. The reaction process and parameters are basically the same as in the examples, the only difference being that the catalyst WO3 in Comparative Example 4 is used instead of the catalyst WO3-WO prepared in Example 1. 3-x -Ov-5.
[0145] Comparative Application Example 2
[0146] The photothermal catalytic material provided in this comparative example catalyzes the photothermal catalytic reaction of cyclohexane. The reaction process and parameters are basically the same as in the examples, the only difference being the use of WO3 catalyst from Comparative Example 2. 3-x -Ov replaces the catalyst WO3-WO prepared in Example 1 3-x -Ov-5.
[0147] Comparative Application Example 3
[0148] The photothermal catalytic material provided in this comparative example catalyzes the photothermal catalytic reaction of cyclohexane. The reaction process and parameters are basically the same as in the examples, the only difference being the use of the catalyst C-WO from Comparative Example 3. 3-x The catalyst WO3-WO was prepared instead of that prepared in Example 1. 3-x -Ov-5.
[0149] For the cyclohexane conversion and selectivity of Application Examples 1-6, and Comparative Application Examples 1 to 3, please refer to Table 1.
[0150] Table 1
[0151]
[0152]
[0153] The WO3 and WO3 provided in Examples 1, 2, 3, 4, 5, 6, Comparative Examples 1, 2, and 3 in Table 1 are used as examples. 3-x -Ov、C-WO 3-x WO3-WO 3-x -Ov-5、WO3-WO 3-x -Ov-10、WO3-WO 3-x -Ov-20、C-WO3-WO 3-x -5、C-WO3-WO 3-x -10 and C-WO3-WO 3-x-20 under the same conditions, photothermal synergistic catalytic oxidation of cyclohexane was carried out, WO3-WO 3-x The photothermal catalytic oxidation of cyclohexane by -Ov-5 achieves a conversion rate 1.62 times that of pure WO3, which is higher than that of WO3. 3-x -Ov is 1.23 times that of C-WO. 3-x 1.12 times; WO3-WO 3-x The conversion rate of cyclohexane oxidation by the photothermal catalysis of -Ov-10 is 1.81 times that of pure WO3, which is higher than that of WO3. 3-x -Ov is 1.36 times that of C-WO. 3-x 1.25 times; WO3-WO 3-x The conversion rate of cyclohexane oxidation by the photothermal catalysis of -Ov-20 is 1.59 times that of pure WO3, which is higher than that of WO3. 3-x -Ov is 1.20 times that of C-WO 3-x 1.10 times; C-WO3-WO 3-x The conversion rate of photothermal catalytic oxidation of cyclohexane is 1.85 times that of pure WO3, which is higher than that of WO4. 3-x 1.39 times that of C-WO 3-x 11.28 times, C-WO3-WO 3-x The conversion rate of photothermal catalytic oxidation of cyclohexane by -10 is 2.04 times that of pure WO3, which is WO3. 3-x 1.54 times that of C-WO 3-x 1.41 times, C-WO3-WO 3-x The conversion rate of photothermal catalytic oxidation of cyclohexane at -20°C is 1.83 times that of pure WO3, which is higher than that of WO3. 3-x 1.38 times that of C-WO 3-x 1.27 times; indicating C-WO3-WO 3-x The composite material exhibits stronger catalytic performance than pure WO3 and pure WO4 in the photothermal catalytic oxidation of cyclohexane. 3-x -Ov、C-WO 3-x and WO3-WO 3-x -Ov, oxygen vacancies can improve the photothermal catalytic performance of materials, and more crystal facets are exposed, providing more active sites.
Claims
1. A method for preparing a composite catalytic material for photocatalytic oxidation of cyclohexane, characterized in that, Comprise the following steps in turn: S1. Preparation of WO3 nanorods: Add tungsten source and sodium salt into ultrapure water, adjust the pH of the system to be acidic, hydrothermal reaction at 160-200℃ for 20-24h, and the reaction product is obtained by washing and drying to obtain WO3 nanorods; The molar ratio of sodium tungstate dihydrate and sodium chloride is 1:1.5-1:2; S2. Preparation of WO3-WO 3-x The WO3 nanorods prepared in step 1) are added into an ethanol solution and ultrasonically dispersed, then centrifuged, and the WO3 nanorods after centrifugation are added into a solvent and a tungsten source, and ultrasonically dispersed uniformly, and then hydrothermal reaction is carried out at 150-170°C for 12-36 hours; the reaction product is washed, dried and obtained as WO3-WO 3-x : S3. Preparation of WO3-WO 3-x -Ov WO3-WO 3-x WO3-WO 3-x -Ov. The molar ratio of tungsten hexachloride and WO3 nanorods is 1:5-1:
20.
2. The method for preparing a composite catalytic material for photocatalytic cyclohexane oxidation reaction according to claim 1, characterized in that, Also include: S4. Preparation of C-WO3-WO 3-x WO3-WO prepared by S3 3-x -Ov was placed in a tube furnace and calcined under an argon atmosphere for 1-2 hours. The product after calcination at 250-300℃ was then placed in a muffle furnace and calcined under an air atmosphere for 0.5-2 hours to obtain C-WO3-WO. 3-x .
3. The method for preparing a composite catalytic material for photocatalytic cyclohexane oxidation reaction according to claim 1, characterized in that, S1. The adjustment of the pH of the system to be acidic is to adjust the pH to 2 with hydrochloric acid.
4. The method for preparing a composite catalytic material for photocatalytic cyclohexane oxidation reaction according to claim 1, characterized in that, S1. The tungsten source is sodium tungstate dihydrate; the sodium salt is sodium chloride.
5. The method for preparing a composite catalytic material for photocatalytic cyclohexane oxidation reaction according to claim 1, characterized in that, S2. The tungsten source is tungsten hexachloride.
6. The method for preparing a composite catalytic material for photocatalytic cyclohexane oxidation reaction according to claim 1, characterized in that, S2. The ethanol solution is an ethanol aqueous solution with an ethanol volume fraction of 90%; the solvent is anhydrous ethanol.
7. A composite catalytic material for photocatalytic oxidation of cyclohexane, characterized in that, WO3-WO prepared by the preparation method of any one of claims 1, 3, 4, 5, 6 3-x catalyst.
8. A composite catalytic material for photocatalytic oxidation of cyclohexane, characterized in that, C-WO3-WO prepared by the preparation method of any one of claims 2-6 3-x catalyst.
9. Use of the composite catalytic material of claim 7 or 8 as a catalyst for photocatalytic oxidation of cyclohexane.
10. A method of photocatalytic oxidation of cyclohexane, characterized by, Comprise the following steps in turn: 1) Weigh the composite photo-thermal catalytic material of claim 7 or 8 and dissolve it in cyclohexane and a solvent to obtain a reaction solution; 2) Pour the solution prepared in step 1) into a photo-thermal reactor, seal the reactor, and fill it with 1-2 MPa of dry air; 3) React at 100-150℃ under xenon lamp irradiation for 6-10h; 4) After the reaction is completed, the reactor is cooled to room temperature, the reacted solution is taken out, and gas chromatography is used for analysis; The ratio of the composite photo-thermal catalytic material to cyclohexane is 1.5-2.5mg:1mL.