CN114433224B - Composite catalyst and preparation method and application thereof - Google Patents
Composite catalyst and preparation method and application thereof Download PDFInfo
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- C07C45/32—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by oxidation with molecular oxygen
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Abstract
The invention relates to a composite catalyst, a preparation method and application thereof, wherein the method comprises the following steps: mixing the carbon nano material with a molecular sieve containing a template agent to obtain a mixture, and carrying out sectional roasting treatment on the mixture; the sectional firing process includes a first firing process and a second firing process that are sequentially performed. The composite catalyst prepared by the method has excellent reaction performance in the selective oxidation reaction of alkane.
Description
Technical Field
The invention relates to a composite catalyst, a preparation method and application thereof.
Background
The carbon nanomaterial is similar to the common nanomaterial in optical, electrical, magnetic and other aspects and has the special properties of quantum size effect, small size effect, macroscopic quantum tunneling effect and the like. In 2004, fine carbon nano particles with the size smaller than 10nm, which are found when single-layer carbon nano tubes are purified by an electrophoresis method, are named as carbon dots for the first time, and are novel small-size carbon nano materials. Compared with organic dyes and traditional semiconductor quantum dots, the carbon dots have unique optical and electrical characteristics besides good water solubility, high stability, low toxicity and good biocompatibility. Therefore, the research on the properties and the application of the carbon dots is getting more and more attention, and the carbon dots can be applied to the related fields of energy problems, environmental protection, photovoltaic devices and the like. Green catalytic oxidation materials such as titanium silicalite have been developed in the beginning of the eighties of the last century, which have not only the catalytic oxidation of titanium, but also shape selectivity and excellent stability. As the pollution-free low-concentration hydrogen peroxide can be used as the oxidant in the oxidation reaction of the organic matters, the problems of complex process and environmental pollution in the oxidation process are avoided, and the method has the advantages of incomparable energy conservation, economy, environmental friendliness and the like of the traditional oxidation system, has good reaction selectivity and has great industrial application prospect. However, the repeatability, stability, cost and other aspects of the synthesis method are not ideal at present. Therefore, improving the corresponding synthetic modification method is a key to material development.
Disclosure of Invention
The invention aims to provide a composite catalyst, a preparation method and application thereof, and the composite catalyst prepared by the method has excellent reaction performance in the selective oxidation reaction of alkane.
In order to achieve the above object, a first aspect of the present invention provides a method for preparing a composite catalyst, the method comprising: mixing a carbon nanomaterial with a molecular sieve containing a template agent to obtain a mixture, and carrying out sectional roasting treatment on the mixture;
the sectional roasting treatment at least comprises a first roasting treatment and a second roasting treatment which are sequentially carried out;
the conditions of the first firing treatment include: in a closed environment, heating the mixture from an initial temperature to a final temperature, wherein the initial temperature is 0-80 ℃, the final temperature is 300-600 ℃, the heating rate is 0.1-5 ℃/min, and the total time of the first roasting treatment is 1-12 hours;
the conditions of the second firing treatment include: in the open environment, the temperature is 300-600 ℃ and the time is 1-12 hours.
Optionally, the sum of the total time of the first firing treatment and the time of the second firing treatment is 2 to 24 hours.
Optionally, the end temperature of the first firing process is the same as the temperature of the second firing process.
Optionally, the weight ratio of the carbon nanomaterial to the molecular sieve containing the template agent is 1: (1 to 100), preferably 1: (5-20);
the content of the template agent is 2-20 wt% based on the total weight of the molecular sieve containing the template agent, and the average particle size of the molecular sieve containing the template agent is 50-500 nm.
Optionally, the template agent is one or more selected from quaternary amine alkali compounds, aliphatic amine compounds and alcohol amine compounds;
the quaternary amine alkali compound is selected from tetraethylammonium hydroxide, tetrapropylammonium hydroxide or tetrabutylammonium hydroxide, or a combination of two or three of the quaternary amine alkali compound and the tetrapropylammonium hydroxide;
the fatty amine compound is selected from ethylamine, n-butylamine, butanediamine or hexamethylenediamine, or a combination of two or three of the above;
the alcohol amine compound is monoethanolamine, diethanolamine or triethanolamine, or a combination of two or three of the monoethanolamine, diethanolamine or triethanolamine.
Optionally, the carbon nanomaterial comprises one or more of carbon nanotubes, graphene, fullerene, nano graphite, nano diamond and activated carbon;
the molecular sieve in the molecular sieve containing the template agent is one or more selected from TS-1, TS-2, ti-MCM-22, ti-MCM-41, ti-SBA-15 and Ti-ZSM-48.
The second aspect of the invention provides a composite catalyst prepared by the method provided by the first aspect of the invention.
Optionally, the composite catalyst contains a modified molecular sieve and a modified carbon nanomaterial, wherein the content of the modified molecular sieve is 40-99 wt%, the silicon-titanium molar ratio of the modified molecular sieve is 15-50, and the nitrogen content of the modified carbon nanomaterial is 0.01-5 wt%.
In a third aspect, the present invention provides the use of a composite catalyst as provided in the second aspect of the present invention in the selective oxidation of cycloalkanes.
Optionally, the method of selective catalytic oxidation of cycloalkanes comprises: contacting cycloalkane with said composite catalyst to effect an oxidation reaction;
the weight ratio of the dosage of the cycloalkane to the dosage of the composite catalyst is 100: (0.1 to 20), and the conditions for the oxidation reaction include: the temperature is 80-200 ℃ and the time is 1-24 hours.
Through the technical scheme, the composite catalyst prepared by the method has excellent reaction performance in the selective oxidation of cycloalkane.
Additional features and advantages of the invention will be set forth in the detailed description which follows.
Detailed Description
The following describes specific embodiments of the present invention in detail. It should be understood that the detailed description and specific examples, while indicating and illustrating the invention, are not intended to limit the invention.
The first aspect of the present invention provides a method of preparing a composite catalyst, the method comprising: mixing the carbon nano material with a molecular sieve containing a template agent to obtain a mixture, and carrying out sectional roasting treatment on the mixture;
the sectional roasting treatment at least comprises a first roasting treatment and a second roasting treatment which are sequentially carried out;
the conditions of the first firing treatment include: under a closed environment, the mixture is heated from an initial temperature to an end temperature, wherein the initial temperature is 0-80 ℃, the end temperature is 300-600 ℃, the heating rate is 0.1-5 ℃/min, and the total time of the first roasting treatment is 1-12 hours;
the conditions of the second firing treatment include: in the open environment, the temperature is 300-600 ℃ and the time is 1-12 hours.
The first roasting treatment and the second roasting treatment which are sequentially carried out are that the carbon nano material and the molecular sieve containing the template agent are mixed to obtain a mixture, the mixture is subjected to the first roasting treatment, and then the product obtained by the first roasting treatment is subjected to the second roasting treatment. In the method, the composite catalyst with good selectivity on the oxidation of alkane can be prepared by taking the mixture of the carbon nano material and the molecular sieve containing the template agent as raw materials and adopting the step-by-step roasting process.
In a preferred embodiment, the conditions of the first calcination treatment include: under a closed environment, heating the mixture from an initial temperature to an end temperature, wherein the initial temperature is 20-60 ℃, the end temperature is 350-550 ℃, the heating rate is 0.5-2 ℃/min, and the total time of the first roasting treatment is 2-12 hours; the conditions of the second firing treatment include: in the open environment, the temperature is 350-550 ℃ and the time is 1-6 hours.
According to the invention, the closed environment refers to that the space for placing the object to be roasted in the roasting equipment during the roasting treatment is free from gas exchange with the outside; the open environment refers to the space in which the object to be roasted is placed in the roasting equipment during the roasting treatment and the outside has gas exchange.
According to the present invention, before the first firing treatment is started, the firing atmosphere is air, an oxygen-deficient atmosphere, or an inert gas atmosphere; the roasting atmosphere of the second roasting treatment is always air or oxygen-deficient atmosphere.
According to the invention, the sum of the total time of the first calcination treatment and the time of the second calcination treatment may vary within a wide range, for example, may be 3 to 20 hours. In one embodiment, the total time of the first calcination treatment is 2 to 10 hours, and the time of the second calcination treatment is 1 to 10 hours. According to the present invention, the first firing treatment and the second firing treatment may be performed in a muffle furnace having a temperature programming function.
In a preferred embodiment, the end temperature of the first calcination treatment is the same as the start temperature of the second calcination treatment, so that the operation is simpler and more convenient, the atmosphere in the system is only required to be changed, and the preparation of the composite catalyst with better selective oxidation characteristics is facilitated.
According to the present invention, the weight ratio of the carbon nanomaterial to the molecular sieve containing the template agent may be varied within a wide range, for example, 1: (1 to 100), preferably 1: (5-20); the template may be present in an amount of 2 to 20 weight percent based on the total weight of the molecular sieve containing the template.
According to the invention, the template agent can be selected from one or more of quaternary amine alkali compounds, aliphatic amine compounds and alcohol amine compounds.
In one embodiment, the quaternary ammonium base compound can have a molecular formula (R) 1 ) 4 NOH, where R 1 Can be selected from C 1 -C 4 Straight chain alkyl and C 3 -C 4 For example methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl or methallyl. Preferably, the quaternary amine base compound is selected from tetraethylammonium hydroxide, tetrapropylammonium hydroxide, or tetrabutylammonium hydroxide, or a combination of two or three thereof.
The molecular general formula of the fatty amine compound can be R 2 (NH 2 ) n Wherein R is 2 May be C 1 -C 6 Straight chain alkyl and C 3 -C 6 At least one of the branched alkyl groups of (1), e.g. methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl or n-hexyl, R 2 May also be C 1 -C 6 Alkylene of (a), such as methylene, ethylene, n-propylene, n-butylene or n-hexylene, n is an integer of 1 or 2. Preferably, the fatty amine compound is selected from ethylamine, n-butylamine, butanediamine or hexamethylenediamine, or a combination of two or three thereof;
the alcohol amine compound may have a molecular formula (HOR) 3 ) m NH (3-m) Wherein R is 3 May be C 1 -C 4 M is an integer of 1, 2 or 3. Preferably, the alcohol amine compound is monoethanolamine, diethanolamine or triethanolamine, or a combination of two or three thereof.
According to the invention, the average particle size of the molecular sieve containing the template agent may vary within a wide range, for example, may be 50 to 500nm.
According to the present invention, the carbon nanomaterial is well known to those skilled in the art, and the specific type thereof is not limited, and is preferably one or more of carbon nanotube, graphene, fullerene, nano graphite, nano diamond and activated carbon, more preferably carbon nanotube, and even more preferably multiwall carbon nanotube; examples of molecular sieves containing a templating agent include, but are not limited to, titanium silicalite molecular sieves, which are also well known to those skilled in the art, and may be, for example, one or more of TS-1, TS-2, ti-MCM-22, ti-MCM-41, ti-SBA-15, and Ti-ZSM-48. The carbon nanomaterial and the molecular sieve containing the template agent can be prepared commercially or by self. The preparation methods of the two are well known to those skilled in the art, and are not described in detail herein.
The second aspect of the invention provides a composite catalyst prepared by the method provided by the first aspect of the invention. The composite catalyst is especially suitable for direct selective oxidation of cycloalkane in the absence of solvent.
According to the invention, the composite catalyst comprises a modified molecular sieve and a modified carbon nanomaterial, wherein the content of the modified molecular sieve is 40-99 wt%, the silicon-titanium molar ratio of the modified molecular sieve is 15-50, and the nitrogen content of the modified carbon nanomaterial is 0.01-5 wt%.
In a third aspect, the present invention provides an application of the composite catalyst prepared in the second aspect in selective catalytic oxidation of cycloalkane, wherein the composite catalyst is used as a cycloalkane selective oxidation catalyst.
According to the present invention, a method of selective catalytic oxidation of cycloalkanes may comprise: the cycloalkane is contacted with the composite catalyst and the oxidizing agent to perform the oxidation reaction, and the weight ratio of the amount of the cycloalkane to the amount of the oxidizing agent in the reaction system is not particularly limited and may be changed within a wide range as long as the oxidation of the cycloalkane can be achieved; the weight ratio of naphthenes to the amount of the complex catalyst may vary within a wide range such as 100: (0.1 to 20), preferably 100: (1-10), the conditions of the oxidation reaction may include: the temperature is 80-200 ℃ and the time is 1-24 hours; preferably at a temperature of 100 to 160 ℃ for a time of 2 to 12 hours.
According to the invention, cycloalkanes are cyclohexane, cyclopentane and their halogenated or alkyl derivatives, and the oxidant is oxygen or air. The feeding method is not particularly limited, and in a preferred embodiment, the cycloalkane may be fed at once and the oxidizing agent may be continuously fed.
The invention is further illustrated by the following examples, which are not intended to be limiting in any way.
The multi-walled carbon nanotubes used were commercially available from the national pharmaceutical group chemical company (CNT, average tube diameter 20nm, length 5 μm, ash less than 0.1 wt%).
The template-containing titanium silicalite (TS-1) used was a molecular sieve sample prepared as described in the prior art Zeolite, 1992, vol.12, pages 943-950.
The preparation method comprises the following steps: 22.5 g of tetraethyl orthosilicate was mixed with 7.0 g of tetrapropylammonium hydroxide (25 wt% aqueous solution) and 50 g of distilled water was added to further mix well, a solution consisting of 1.1 g of tetrabutyl titanate and 5.0 g of anhydrous isopropanol was slowly added under vigorous stirring, and the resulting mixture was stirred at 75℃for 3 hours to obtain a colloid. Placing the colloid into a stainless steel reaction kettle, and standing at a constant temperature of 170 ℃ for 3 days to obtain a mixture of crystallized products; the mixture was filtered, washed with water, and dried at 110℃for 60 minutes to obtain a template-containing titanium silicalite molecular sieve (TS-1) having a template content of 14% by weight and an average particle size of 220nm.
The modified molecular sieve content and the silicon-titanium molar content ratio of the composite catalyst are measured by adopting X-ray fluorescence spectroscopy (XRF), and the nitrogen content in the modified carbon nanomaterial is measured by adopting X-ray photoelectron spectroscopy (XPS).
The composition of the alkane selective oxidation product was analyzed by gas chromatography, and on the basis of this, the cyclohexane conversion, cyclohexanone selectivity and cyclohexanol selectivity were calculated using the following formulas, respectively:
cyclohexane conversion= [ (molar amount of cyclohexane added-molar amount of unreacted cyclohexane)/molar amount of cyclohexane added ] ×100%;
cyclohexanone selectivity= [ molar amount of cyclohexanone generated by reaction/(molar amount of cyclohexane added-molar amount of unreacted cyclohexane) ] ×100%;
cyclohexanol selectivity= [ molar amount of cyclohexanol produced by reaction/(molar amount of cyclohexane added-molar amount of unreacted cyclohexane) ]x100%.
Example 1
CNT and titanium silicon molecular sieve (TS-1) containing template agent are mixed according to the weight ratio of 1:10, uniformly mixing, putting the mixture into a crucible (the crucible is covered and sealed), then transferring the mixture into a muffle furnace, closing a muffle furnace door, and starting first roasting treatment, wherein the initial temperature of the first roasting treatment is 20 ℃, the end temperature is 400 ℃, the heating rate is 2 ℃/min, and the total roasting time is 4.5 hours; and opening a crucible cover after the first roasting treatment is finished, and performing second roasting treatment for 2.5 hours at 400 ℃, and cooling and taking out to obtain the composite catalyst A. The detection shows that the content of the modified molecular sieve in the composite catalyst A is 88 wt%, the silicon-titanium molar ratio of the modified molecular sieve is 24, and the nitrogen content in the modified carbon nano material is 0.17 wt%.
Example 2
CNT and TS-1 are mixed according to the weight ratio of 1:1, uniformly mixing, placing the mixture into a crucible (the crucible is covered and sealed), then transferring the mixture into a muffle furnace, closing a muffle furnace door, and starting first roasting treatment, wherein the initial temperature of the first roasting treatment is 60 ℃, the end temperature is 500 ℃, the heating rate is 4 ℃/min, and the roasting time is 3.5h; and opening a crucible cover after the first roasting treatment is finished, performing second roasting treatment for 0.5h at the temperature of 500 ℃, and cooling and taking out to obtain the composite catalyst B. The detection shows that the modified molecular sieve in the composite catalyst B has a content of 43 wt%, the silicon-titanium molar ratio of the modified molecular sieve is 26, and the nitrogen content in the modified carbon nano material is 0.03 wt%.
Example 3
CNT and TS-1 are mixed according to the weight ratio of 1:50, uniformly mixing, placing the mixture into a crucible (the crucible is covered and sealed), transferring the mixture into a muffle furnace, closing a muffle furnace door, and starting first roasting treatment, wherein the initial temperature of the first roasting treatment is 30 ℃, the end temperature is 350 ℃, the heating rate is 1 ℃/min, and the roasting time is 8 hours; and opening the crucible cover after the first roasting treatment is finished, performing second roasting treatment for 6 hours at 350 ℃, and cooling and taking out to obtain the composite catalyst C. Through detection, the content of the modified molecular sieve in the composite catalyst C is 97 wt%, the silicon-titanium molar ratio of the modified molecular sieve is 23, and the nitrogen content in the modified carbon nano material is 4.4 wt%.
Example 4
Composite catalyst D was prepared in the same manner as in example 1 except that the temperature of the second calcination treatment was 350 ℃. The detection shows that the modified molecular sieve content in the composite catalyst D is 89 wt%, the silicon-titanium molar ratio of the modified molecular sieve is 27, and the nitrogen content in the modified carbon nano material is 0.19 wt%.
Example 5
Composite catalyst E was prepared in the same manner as in example 1 except that the initial temperature of the first calcination treatment was 20 ℃, the end temperature was 400 ℃, the temperature-rising rate was 2 ℃/min, and the calcination time was 10 hours; and opening the crucible cover after the first roasting treatment is finished, and performing second roasting treatment for 12 hours at 400 ℃. Through detection, the content of the modified molecular sieve in the composite catalyst E is 85 wt%, the silicon-titanium molar ratio of the modified molecular sieve is 28, and the nitrogen content in the modified carbon nano material is 0.14 wt%.
Example 6
Composite catalyst F was prepared in the same manner as in example 1, except that the weight ratio of the amounts of CNT and TS-1 was 1:25. according to detection, the content of the modified molecular sieve in the composite catalyst F is 93 wt%, the silicon-titanium molar ratio of the modified molecular sieve is 22, and the nitrogen content in the modified carbon nano material is 0.06 wt%.
Comparative example 1
Roasting the titanium silicalite molecular sieve (TS-1) containing the template agent at 500 ℃ for 8 hours to obtain the titanium silicalite molecular sieve without the template agent. In a muffle furnace, CNT and a titanium-silicon molecular sieve without a template agent are mixed according to the weight ratio of 1:10 are evenly mixed and then put into a crucible (the crucible is covered and sealed), then the crucible is put into a muffle furnace, the muffle furnace door is closed, the temperature is raised from 20 ℃ to 400 ℃ at the heating rate of 2 ℃/min, and then the crucible is baked for 4.5 hours, the crucible cover is opened, the crucible is baked for 2.5 hours at 400 ℃, and the composite catalyst a with the comparison is obtained after cooling and taking out. According to detection, the content of the titanium-silicon molecular sieve in the catalyst a is 91 wt%, the silicon-titanium molar ratio of the titanium-silicon molecular sieve is 25, and the modified carbon nano material contains no nitrogen.
Comparative example 2
The CNT and the titanium silicon molecular sieve (TS-1) containing the template agent are mixed by physical and mechanical, and the weight ratio is 1:10 to obtain the comparative composite catalyst b. Through detection, the titanium-silicon molecular sieve content in the catalyst b is 78 wt%, the silicon-titanium molar ratio of the titanium-silicon molecular sieve is 26, and the modified carbon nanomaterial contains no nitrogen.
Comparative example 3
Comparative composite catalyst c was prepared in the same manner as in example 1, except that only the first calcination treatment was performed and the second calcination treatment was not performed. The detection shows that the titanium-silicon molecular sieve content in the catalyst c is 85 wt%, the silicon-titanium molar ratio of the titanium-silicon molecular sieve is 26, and the nitrogen content in the modified carbon nano material is 1.24 wt%.
Comparative example 4
Comparative composite catalyst d was prepared in the same manner as in example 1, except that only the second calcination treatment was performed and the first calcination treatment was not performed. The detection shows that the titanium-silicon molecular sieve in the catalyst d has 89 weight percent, the silicon-titanium molar ratio of the titanium-silicon molecular sieve is 29, and the nitrogen content in the modified carbon nano material is 0 weight percent.
Comparative example 5
Comparative composite catalyst e was prepared in the same manner as in example 1 except that the first calcination treatment was performed without sealing the crucible with a cover. Through detection, the content of the titanium-silicon molecular sieve in the catalyst e is 81 wt%, the silicon-titanium molar ratio of the titanium-silicon molecular sieve is 25, and the nitrogen content in the modified carbon nano material is 0 wt%.
Test examples
And (3) under the condition of no solvent, the selective catalytic oxidation of cyclohexane.
250mg of the composite catalyst prepared in the examples and comparative examples and 25mL of cyclohexane were added to a 50mL autoclave equipped with a water condenser, respectively, without other solvents. After that, the mixture was stirred under mild conditions (130 ℃ C., oxygen as an oxidizing agent, continuously introducing oxygen until the pressure was maintained at 2.0 MPa) and reacted for 5 hours, and after separating the catalyst by centrifugation and filtration, the composition of the oxidized product was analyzed.
TABLE 1
| Catalyst source | Catalyst numbering | Cyclohexane conversion% | Cyclohexanone selectivity,% | Cyclohexanol selectivity,% |
| Example 1 | A | 11.5 | 51 | 43 |
| Example 2 | B | 10.6 | 49 | 42 |
| Example 3 | C | 9.6 | 46 | 48 |
| Example 4 | D | 8.5 | 40 | 45 |
| Example 5 | E | 9.1 | 45 | 44 |
| Example 6 | F | 8.7 | 41 | 41 |
| Comparative example 1 | a | 3.1 | 18 | 39 |
| Comparative example 2 | b | 4.3 | 12 | 25 |
| Comparative example 3 | c | 5.0 | 32 | 35 |
| Comparative example 4 | d | 4.9 | 28 | 33 |
| Comparative example 5 | e | 4.8 | 25 | 27 |
The composite catalyst prepared by the method has good catalytic performance on selective oxidation of naphthenes without solvent.
The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the specific details of the above embodiments, and various simple modifications can be made to the technical solution of the present invention within the scope of the technical concept of the present invention, and all the simple modifications belong to the protection scope of the present invention.
In addition, the specific features described in the above embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, various possible combinations are not described further.
Moreover, any combination of the various embodiments of the invention can be made without departing from the spirit of the invention, which should also be considered as disclosed herein.
Claims (11)
1. A method of preparing a composite catalyst, the method comprising: mixing a carbon nanomaterial with a molecular sieve containing a template agent to obtain a mixture, and carrying out sectional roasting treatment on the mixture;
the sectional roasting treatment at least comprises a first roasting treatment and a second roasting treatment which are sequentially carried out;
the conditions of the first firing treatment include: in a closed environment, heating the mixture from an initial temperature to an end point temperature, wherein the initial temperature is 0-80 ℃, the end point temperature is 300-600 ℃, the heating rate is 0.1-5 ℃/min, and the total time of the first roasting treatment is 1-12 hours;
the conditions of the second firing treatment include: in the open environment, the temperature is 300-600 ℃ and the time is 1-12 hours.
2. The method of claim 1, wherein the sum of the total time of the first firing treatment and the time of the second firing treatment is 3 to 24 hours.
3. The method of claim 1, wherein the end point temperature of the first firing process is the same as the temperature of the second firing process.
4. The method of claim 1, wherein the carbon nanomaterial to template-containing molecular sieve is used in an amount by weight of 1: (1-100);
the content of the template agent is 2-20 wt% based on the total weight of the molecular sieve containing the template agent, and the average particle size of the molecular sieve containing the template agent is 50-500 nm.
5. The method of claim 1, wherein the carbon nanomaterial to template-containing molecular sieve is used in an amount by weight of 1: (5-20).
6. The method of claim 1, wherein the template agent is selected from one or more of quaternary amine base compounds, fatty amine compounds and alcohol amine compounds;
the quaternary amine alkali compound is selected from tetraethylammonium hydroxide, tetrapropylammonium hydroxide or tetrabutylammonium hydroxide, or a combination of two or three of the quaternary amine alkali compound and the tetrapropylammonium hydroxide;
the fatty amine compound is selected from ethylamine, n-butylamine, butanediamine or hexamethylenediamine, or a combination of two or three of the above;
the alcohol amine compound is monoethanolamine, diethanolamine or triethanolamine, or a combination of two or three of the monoethanolamine, diethanolamine or triethanolamine.
7. The method of claim 1, wherein the carbon nanomaterial comprises one or more of carbon nanotubes, graphene, fullerenes, nanographites, nanodiamonds, and activated carbon;
the molecular sieve in the molecular sieve containing the template agent is one or more selected from TS-1, TS-2, ti-MCM-22, ti-MCM-41, ti-SBA-15 and Ti-ZSM-48.
8. A composite catalyst prepared by the method of any one of claims 1-7.
9. The composite catalyst according to claim 8, wherein the composite catalyst comprises a modified molecular sieve and a modified carbon nanomaterial, the modified molecular sieve is contained in an amount of 40-99 wt%, the molar ratio of silicon to titanium of the modified molecular sieve is 15-50, and the nitrogen content of the modified carbon nanomaterial is 0.01-5 wt%.
10. Use of the composite catalyst according to claim 8 or 9 as a cycloalkane selective oxidation catalyst in the selective catalytic oxidation of cycloalkanes.
11. The use according to claim 10, wherein the method of selective catalytic oxidation of cycloalkanes comprises: contacting cycloalkane with said composite catalyst to effect an oxidation reaction;
the weight ratio of the dosage of the cycloalkane to the dosage of the composite catalyst is 100: (0.1 to 20), and the conditions for the oxidation reaction include: the temperature is 80-200 ℃ and the time is 1-24 hours.
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| CN101664696A (en) * | 2008-09-04 | 2010-03-10 | 中国石油化工股份有限公司 | Modification treatment method for titanium silicate molecular sieve |
| CN103373915A (en) * | 2012-04-27 | 2013-10-30 | 中国石油化工股份有限公司 | Method for preparing dicarboxylic acid through catalytic oxidization reaction |
| CN104556109A (en) * | 2013-10-29 | 2015-04-29 | 中国石油化工股份有限公司 | Method for preparing titanosilicate molecular sieve and phenol oxidation method |
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| CN101664696A (en) * | 2008-09-04 | 2010-03-10 | 中国石油化工股份有限公司 | Modification treatment method for titanium silicate molecular sieve |
| CN103373915A (en) * | 2012-04-27 | 2013-10-30 | 中国石油化工股份有限公司 | Method for preparing dicarboxylic acid through catalytic oxidization reaction |
| CN104556109A (en) * | 2013-10-29 | 2015-04-29 | 中国石油化工股份有限公司 | Method for preparing titanosilicate molecular sieve and phenol oxidation method |
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