阅读说明：本技术 一种环酮肟的生产方法 (Production method of cyclic ketoxime ) 是由 朱斌 夏长久 郑爱国 林民 彭欣欣 舒兴田 于 2019-10-29 设计创作，主要内容包括：本发明涉及环酮肟的合成领域,公开了一种环酮肟的生产方法,该方法包括：(I)将催化剂、环酮、氨以及溶剂混合,得到混合物料；(II)在环酮氧化反应条件下,将步骤(I)得到的混合物料与过氧化物接触；其中,所述催化剂包括含金属介孔分子筛,所述含金属介孔分子筛包括：介孔分子筛、氟元素和金属元素,所述金属元素选自IVB族金属元素和IVA族金属元素中的至少一种；金属元素、氟元素和介孔分子筛的摩尔比为1：(0.1-10)：(10-100),其中,介孔分子筛以SiO-2计。该方法环境友好,具有反应物转化率高、产物环酮肟选择性高的特点。(The invention relates to the field of synthesis of cyclic ketoxime, and discloses a production method of cyclic ketoxime, which comprises the following steps: (I) mixing a catalyst, cyclic ketone, ammonia and a solvent to obtain a mixed material; (II) contacting the mixed material obtained in the step (I) with peroxide under the condition of cyclic ketone oxidation reaction; wherein the catalyst comprises a metal-containing mesoporous molecular sieve, and the metal-containing mesoporous molecular sieve comprises: a mesoporous molecular sieve, fluorine and a metal element selected from at least one of group IVB metal elements and group IVA metal elements; the molar ratio of the metal element to the fluorine element to the mesoporous molecular sieve is 1: (0.1-10): (10-100), wherein the mesoporous molecular sieve is SiO 2 And (6) counting. The method is environment-friendly, and has the characteristics of high reactant conversion rate and high selectivity of the product cyclic ketoxime.)

1. A process for producing a cyclic ketoxime, which comprises:

(I) mixing a catalyst, cyclic ketone, ammonia and a solvent to obtain a mixed material;

(II) contacting the mixed material obtained in the step (I) with peroxide under the condition of cyclic ketone oxidation reaction;

wherein the catalyst comprises a metal-containing mesoporous molecular sieve, and the metal-containing mesoporous molecular sieve comprises: a mesoporous molecular sieve, fluorine and a metal element selected from at least one of group IVB metal elements and group IVA metal elements; the molar ratio of the metal element to the fluorine element to the mesoporous molecular sieve is 1: (0.1-10): (10-100), wherein the mesoporous molecular sieve is SiO₂And (6) counting.

2. The production method according to claim 1, wherein the mass ratio of the cyclic ketone, the catalyst and the solvent is 1: (0.01-0.2): (0.5-15), preferably 1: (0.03-0.15): (1-10);

preferably, the molar ratio of cyclic ketone to ammonia is 1: (0.5-5), preferably 1: (1-3);

preferably, in step (1), the ammonia is introduced in the form of aqueous ammonia having a concentration of 20 to 30% by weight.

3. The production process according to claim 1, wherein the molar ratio of the cyclic ketone to the peroxide is 1: (0.5-3), preferably 1: (1-2);

preferably, the peroxide is hydrogen peroxide;

preferably, in step (II), the hydrogen peroxide is introduced in the form of an aqueous hydrogen peroxide solution having a concentration of 1 to 50% by weight.

4. The production method according to any one of claims 1 to 3, wherein the cyclic ketone oxidation reaction conditions include: the temperature is 30-150 ℃, preferably 60-90 ℃; the pressure is 1-5atm, preferably 1-2 atm; the time is 0.1 to 10 hours, preferably 0.5 to 3 hours.

5. The production process according to any one of claims 1 to 4, wherein the cyclic ketone is a cyclic ketone having 5 to 9 carbon atoms, preferably cyclohexanone;

preferably, the solvent is water, C₁-C₆Alcohol of (1), C₂-C₆Acid and C₂-C₈More preferably water.

6. The production method according to any one of claims 1 to 5, wherein, in the metal-containing mesoporous molecular sieve, the mesoporous molecular sieve is selected from at least one of SBA-15, MCM-41, MCM-48, HMS, KIT-6, and MSU;

preferably, the metal element is at least one selected from the group consisting of Ti element, Zr element, Sn element, and Ge element;

preferably, the molar ratio of the metal element, the fluorine element and the mesoporous molecular sieve is 1: (0.2-5): (40-75);

preferably, the molecular sieve containing metal mesoporous has a characteristic peak at the wavelength of 220-230nm as characterized by UV-Vis;

preferably, the average radial diameter of the metal-containing mesoporous molecular sieve is 5 to 35 μm, and more preferably 5 to 28 μm.

7. The production method according to claim 6, wherein the preparation method of the metal-containing mesoporous molecular sieve comprises:

(1) mixing a metal source, a fluorine source and a silicon source to obtain a first material;

(2) mixing the first material with a mesoporous molecular sieve to obtain a second material;

(3) aging the second material;

(4) and drying and roasting the aged product.

8. The production process according to claim 7, wherein the metal source is selected from TiCl₄、TiOSO₄、TiCl₃、TiF₄、H₂TiF₆、(NH₄)₂TiF₆、SnCl₄、ZrCl₄And ZrF₄At least one of;

preferably, the fluorine source is selected from NH₄F. At least one of NaF, KF, and HF;

preferably, the silicon source is an organic silicon source and/or an inorganic silicon source;

further preferably, the silicon source is selected from H₂SiF₆、SiF₄、SiCl₄、(NH₄)₂SiF₆And ethyl orthosilicate.

9. The production method according to claim 7, wherein the molar ratio of the metal source, the fluorine source and the silicon source is 1: (0.1-10): (0.1-10), preferably 1: (0.2-5): (0.2-5), the silicon source is SiO₂Counting;

preferably, the molar ratio of the metal source to the mesoporous molecular sieve is 1: (10-100), more preferably 1: (20-60), wherein the mesoporous molecular sieve is SiO₂And (6) counting.

10. The production method according to claim 7, wherein the aging condition of step (3) includes: under the condition of stirring, the aging temperature is 20-100 ℃, and the aging time is 0.5-24 h;

preferably, the aging conditions include: aging at 20-80 deg.C for 0.5-18 h;

further preferably, the aging conditions include: aging at 25-70 deg.C for 1-12 h;

preferably, the calcination in step (4) is carried out at a temperature of 300-880 ℃, preferably 300-700 ℃, more preferably 400-600 ℃.

11. The production method according to claim 7, wherein the method further comprises: introducing acid to adjust the pH in the step (2); preferably, the acid is introduced in an amount such that the pH of the second material is in the range of 1 to 7, more preferably 3 to 6.5.

Technical Field

The invention relates to the field of synthesis of cyclic ketoxime, and in particular relates to a production method of cyclic ketoxime.

Background

Currently, cyclohexanone oxime is mainly synthesized by using the reaction of hydroxylamine salt and cyclohexanone. This process has two major disadvantages: (1) the dosage of the hydroxylamine salt is high; (2) a large amount of by-product inorganic salts such as ammonium sulfate (Gerd d. catalysis reviews,2001,43(4): 381-441.) are generated, and the process is not environment-friendly.

US4745221A discloses a method for synthesizing cyclohexanone oxime using titanium silicalite molecular sieve or a mixture of silica and titanium silicalite molecular sieve as catalyst, but the selectivity of oxime product of the method is low, only 79.45%, and the utilization rate of hydrogen peroxide is only 68.7%. US4794198A and US5227525A disclose processes for synthesizing cyclohexanone oxime by liquid phase ammoxidation using titanium silicalite molecular sieve as catalyst and tert-butanol-water as solvent, respectively, wherein the conversion rate of cyclohexanone can reach 98.3%, and the selectivity of cyclohexanone oxime can reach 99.6%. EP0496385a1 discloses a process for the liquid phase ammoxidation synthesis of oximes, which employs a multi-step process, i.e. a two-kettle or three-kettle series-connected, multi-point hydrogen peroxide feed process, while ensuring high conversion of cyclohexanone and high selectivity of cyclohexanone oxime, the maximum hydrogen peroxide utilization is only 89%. US06462235B1 discloses a liquid phase process for producing oxime using titanium silicalite TS-1 as a catalyst and aldehyde or ketone, ammonia and hydrogen peroxide as raw materials in the presence of ammonium salt or substituted ammonium salt, which is very effective for macromolecular cyclic ketones, but requires the addition of a cocatalyst ammonium salt or substituted ammonium salt in the reaction to obtain high conversion and selectivity, which increases the cost of the reaction and the difficulty of product separation. CN1432560A discloses a method for synthesizing cyclohexanone oxime by using a titanium silicalite TS-1 with the particle size of 0.1-0.3 mu m as a catalyst, which solves the problem of catalyst separation, but the reaction system still uses tert-butyl alcohol-water as a solvent, and has the defect of complex post-reaction treatment. Therefore, many difficulties still exist in the ammoxidation reaction of the macromolecular cyclic ketone at present.

In order to solve the above problems, it is necessary to develop a novel synthesis process of an environment-friendly cyclic ketoxime.

Disclosure of Invention

The invention aims to overcome the defects of the ammoxidation reaction of cyclic ketone in the prior art, and provides a production method of cyclic ketoxime, which is environment-friendly and has the characteristics of high reactant conversion rate and high selectivity of the product cyclic ketoxime.

In order to achieve the above object, the present invention provides a process for producing a cyclic ketoxime, which comprises:

(I) mixing a catalyst, cyclic ketone, ammonia and a solvent to obtain a mixed material;

(II) contacting the mixed material obtained in the step (I) with peroxide under the condition of cyclic ketone oxidation reaction;

wherein the catalyst comprises a metal-containing mesoporous molecular sieve, and the metal-containing mesoporous molecular sieve comprises: a mesoporous molecular sieve, fluorine and a metal element selected from at least one of group IVB metal elements and group IVA metal elements; the molar ratio of the metal element to the fluorine element to the mesoporous molecular sieve is 1: (0.1-10): (10-100), wherein the mesoporous molecular sieve is SiO₂And (6) counting.

Preferably, the preparation method of the metal-containing mesoporous molecular sieve comprises the following steps:

(1) mixing a metal source, a fluorine source and a silicon source to obtain a first material;

(2) mixing the first material with a mesoporous molecular sieve to obtain a second material;

(3) aging the second material;

(4) and drying and roasting the aged product.

The production method of the cyclic ketoxime provided by the invention is environment-friendly and simple and convenient in post-treatment, can realize the ammoxidation of macromolecular cyclic ketone, and has the advantages of high cyclic ketone conversion rate, high cyclic ketoxime selectivity and high hydrogen peroxide utilization rate. The results of the examples show that in the production method of the cyclic ketoxime, the conversion rate of the reactant and the selectivity of the target product are high, wherein the highest utilization rate of the hydrogen peroxide can reach 99.9%, the highest conversion rate of the reactant cyclohexanone can reach 99.8%, and the highest selectivity of the product cyclohexanone oxime can reach 99.8%, and the effect is remarkable.

Drawings

FIG. 1 is a UV-Vis characterization spectrum of Ti-SBA-15 mesoporous molecular sieve C-1 prepared in preparation example 1 and Ti-SBA-15 mesoporous molecular sieve X prepared in preparation comparative example 1;

FIG. 2 is a SEM representation of the Ti-SBA-15 mesoporous molecular sieve X prepared in comparative example 1;

FIG. 3 is a SEM representation spectrum of Ti-SBA-15 mesoporous molecular sieve C-1 prepared in preparation example 1.

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

The invention provides a method for producing cyclohexanone oxime, which comprises the following steps:

(I) mixing a catalyst, cyclic ketone, ammonia and a solvent to obtain a mixed material;

(II) contacting the mixed material obtained in the step (I) with peroxide under the condition of cyclic ketone oxidation reaction;

wherein the catalyst comprises a metal-containing mesoporous molecular sieve, and the metal-containing mesoporous molecular sieve comprises: a mesoporous molecular sieve, fluorine and a metal element selected from at least one of group IVB metal elements and group IVA metal elements; gold (Au)The mol ratio of the metal element, the fluorine element and the mesoporous molecular sieve is 1: (0.1-10): (10-100), wherein the mesoporous molecular sieve is SiO₂And (6) counting.

According to the present invention, it is preferable that the content of the metal-containing mesoporous molecular sieve in the catalyst is 50 to 100% by weight. Besides the metal-containing mesoporous molecular sieve, the catalyst can also contain silicon dioxide and/or other titanium-containing molecular sieves. That is, the catalyst may be an assembly of the metal-containing mesoporous molecular sieve and silica, an assembly of the metal-containing mesoporous molecular sieve and other titanium-containing molecular sieves, or an assembly of the metal-containing mesoporous molecular sieve, other titanium-containing molecular sieves, and silica.

According to a preferred embodiment of the present invention, the catalyst is a metal-containing mesoporous molecular sieve, i.e. the content of the metal-containing mesoporous molecular sieve in the catalyst is 100%.

According to the present invention, the XRF method can be used to determine the molar ratio of the metal element, the fluorine element and the mesoporous molecular sieve in the metal-containing mesoporous molecular sieve.

According to the present invention, preferably, the mass ratio of the cyclic ketone, the catalyst and the solvent is 1: (0.01-0.2): (0.5-15), preferably 1: (0.03-0.15): (1-10).

Preferably, the molar ratio of cyclic ketone to ammonia is 1: (0.5-5), preferably 1: (1-3).

In the present invention, in the step (1), ammonia may be introduced in the form of gaseous ammonia or may be introduced in the form of liquid ammonia. Preferably, in step (1), the ammonia is introduced in the form of aqueous ammonia. The concentration of the aqueous ammonia in the present invention is selected in a wide range, and the concentration of the aqueous ammonia is preferably 20 to 30% by weight.

In the step (1), the mixing is not particularly limited, and preferably, the mixing is under stirring conditions.

According to the invention, the molar ratio of cyclic ketone to peroxide is preferably 1: (0.5-3), preferably 1: (1-2).

In the present invention, the peroxide is selected from a wide range as long as it is a compound containing a peroxy group, and specifically, it may be an inorganic peroxide or an organic peroxide. Preferably, the peroxide is selected from at least one of hydrogen peroxide, peroxyacetic acid, peroxypropionic acid and trifluoroperoxyacetic acid. Further preferably, the peroxide is hydrogen peroxide.

Preferably, the hydrogen peroxide is introduced in the form of an aqueous hydrogen peroxide solution, preferably in a concentration of 1 to 50 wt.%, more preferably 5 to 45 wt.%, more preferably 20 to 40 wt.%.

According to the present invention, preferably, the cyclic ketone oxidation reaction conditions include: the temperature is 30-150 ℃, preferably 60-90 ℃; the pressure is 1-5atm, preferably 1-2 atm; the time is 0.1 to 10 hours, preferably 0.5 to 3 hours.

According to one embodiment of the invention, it may be that peroxide is introduced into the mixed mass. The above-mentioned times of the present invention do not include the peroxide addition time.

The feeding method of the peroxide is not particularly limited in the present invention, and the peroxide can be introduced in a dropwise manner in order to avoid decomposition of the peroxide by a conventional technical means in the art. The dropping speed is selected in a wide range and can be determined by a person skilled in the art according to the test scale. For example, the dropping time may be 1 to 8 hours, preferably 1 to 2 hours.

Preferably, after step (II), the process further comprises separating the catalyst from the reaction product. The separation in the present invention is not particularly limited, and may be carried out by a conventional operation in the art, for example, filtration, as long as the object of solid-liquid separation can be achieved. The separated liquid can be separated into the target product by adopting a common distillation or rectification method, and the distillation or rectification is a conventional choice in the field and is not described again.

According to the invention, the method provided by the invention is particularly suitable for ammoxidation of macromolecular cyclic ketone, preferably the cyclic ketone has 5-9C atoms, and more preferably cyclohexanone.

The solvent used in the process for producing a cyclic ketoxime of the present invention is not particularly limited, and preferably, the solvent is selected from the group consisting of water and C₁-C₆Alcohol of (1), C₂-C₆Acid and C₂-C₈One or more of (a) nitrile(s). In the present invention, the term "C" is used₁-C₆The alcohol of (1) represents an alcohol having a total number of carbon atoms of 1 to 6, including a linear alcohol, a branched alcohol or a cyclic alcohol, and the "C" is₂-C₆The expression "acid" denotes an acid having a total number of carbon atoms of 2 to 6, including a straight chain acid, a branched chain acid or a cyclic acid, said "C" being₂-C₈The "nitrile" of (a) means a nitrile having a total number of carbon atoms of 2 to 8, and includes a straight chain nitrile, a branched chain ketone or a cyclic nitrile. Further preferably, the solvent is at least one selected from the group consisting of water, methanol, ethanol, tert-butanol, n-propanol, isopropanol and sec-butanol, and more preferably water.

According to a preferred embodiment of the present invention, in the metal-containing mesoporous molecular sieve, the mesoporous molecular sieve is selected from at least one of SBA-15, MCM-41, MCM-48, HMS, KIT-6 and MSU, more preferably from at least one of SBA-15, MCM-41, MCM-48, HMS and KIT-6. The adoption of the optimal mode is more beneficial to improving the catalytic performance of the metal-containing mesoporous molecular sieve.

In the invention, the mesoporous molecular sieve can be obtained by commercial products or can be prepared by the existing method.

According to the present invention, the metal element is selected from at least one of a group IVB metal element and a group IVA metal element, preferably, the metal element is selected from at least one of a Ti element, a Zr element, a Sn element and a Ge element, more preferably, at least one of a Ti element, a Zr element and a Sn element, and most preferably, a Ti element.

According to the present invention, it is preferable that the molar ratio of the metal element, the fluorine element and the mesoporous molecular sieve is 1: (0.2-5): (40-75). At such a preferable ratio, it is more advantageous in the production of the cyclic ketoxime to improve the reaction conversion and the product selectivity.

Preferably, the metal-containing mesoporous molecular sieve has a characteristic peak at the wavelength of 220-230nm as characterized by UV-Vis. The characteristic peak indicates that the metal element in the metal mesoporous molecular sieve of the invention has a specific occurrence state.

Preferably, the average radial diameter of the metal-containing mesoporous molecular sieve is 5 to 35 μm, and more preferably 5 to 28 μm. The average radial diameter of the metal-containing mesoporous molecular sieve is measured by a TEM method.

According to the method for producing a cyclic ketoxime provided by the invention, the object of the invention can be achieved as long as the metal-containing mesoporous molecular sieve is adopted, the selection range of the preparation method of the metal-containing mesoporous molecular sieve is wide, and preferably, the preparation method of the metal-containing mesoporous molecular sieve comprises the following steps:

(1) mixing a metal source, a fluorine source and a silicon source to obtain a first material;

(2) mixing the first material with a mesoporous molecular sieve to obtain a second material;

(3) aging the second material;

(4) and drying and roasting the aged product.

The choice of the metal according to the invention can be as described above and will not be described in detail here.

The metal source of the present invention can be selected from a wide range of metals as long as the metal source can provide the metal, for example, a soluble salt containing a metal. Preferably, the metal source is selected from TiCl₄、TiOSO₄、TiCl₃、TiF₄、H₂TiF₆、(NH₄)₂TiF₆、SnCl₄、ZrCl₄And ZrF₄At least one of (1).

In the present invention, the fluorine source may be selected from a wide range as long as it can provide fluorine, for example, hydrofluoric acid and/or a fluorine-containing soluble salt. Preferably, the fluorine source is selected from NH₄F. At least one of NaF, KF and HF.

In the present invention, the term "soluble" means that the solvent can be dissolved directly or dissolved in a solvent under the action of a cosolvent.

The silicon source selection range of the invention is wider, and the silicon source can be various silicon sources which are conventionally used in the field. Specifically, the silicon source is an organic silicon source and/or an inorganic silicon source. Preferably, the silicon source is selected from H₂SiF₆、SiF₄、SiCl₄、(NH₄)₂SiF₆And ethyl orthosilicate. The adoption of the preferred embodiment is more beneficial to improving the catalytic performance of the prepared molecular sieve.

According to the present invention, the fluorine source and the silicon source may be introduced in the form of a solution (e.g., an aqueous solution).

According to the present invention, the mixing process in step (1) may optionally further include a solvent, if the metal source, the fluorine source and the silicon source can satisfy the requirement of uniform mixing, i.e. the solvent does not need to be introduced, and the solvent (preferably water) needs to be introduced otherwise. In the present invention, the amount of the solvent to be introduced is not particularly limited, and may be appropriately selected depending on the amounts of the metal source, the fluorine source and the silicon source to be introduced, as long as the mixing is sufficient.

According to a preferred embodiment of the present invention, the step (1) comprises: and mixing a metal source, a fluorine source, a solvent and a silicon source to obtain the first material.

In the present invention, the mixing in the step (1) is not particularly limited, and may be performed under stirring conditions or ultrasonic conditions. Preferably, the mixing in step (1) is carried out under ultrasound, which is more favorable for material mixing.

According to a preferred embodiment of the present invention, the metal source, the fluorine source and the mesoporous molecular sieve are used in amounts such that the molar ratio of the modified metal element, the fluorine element and the mesoporous molecular sieve in the obtained metal-containing mesoporous molecular sieve is 1: (0.1-10): (10-100), preferably 1: (0.2-5): (40-75). It should be noted that, if the metal source and the silicon source contain F element during the preparation process, which can provide part of F element, the amount of the fluorine source can be reduced accordingly. The person skilled in the art knows how to select the metal source, the fluorine source and the ratio of the amount of mesoporous molecular sieve based on the above disclosure.

According to the present invention, it is preferable that the molar ratio of the metal source, the fluorine source, and the silicon source is 1: (0.1-10): (0.1-10), preferably 1: (0.2-5): (0.2-5), the silicon source is SiO₂And (6) counting.

According to the method provided by the invention, the selection of the mesoporous molecular sieve is as described above, and details are not repeated here.

According to the present invention, preferably, the molar ratio of the metal source to the mesoporous molecular sieve is 1: (10-100), more preferably 1: (20-60), wherein the mesoporous molecular sieve is SiO₂And (6) counting.

In the present invention, the mixing in the step (2) is not particularly limited, and may be performed under stirring conditions as long as the mesoporous molecular sieve and the first material are uniformly mixed.

According to the invention, the temperature of the ageing is preferably 20 to 100 ℃ and the ageing time can be 0.5 to 24 hours. In order to further optimize the aging effect, it is preferable that the aging in step (3) is performed under stirring conditions. The stirring is preferably carried out using a magnetic stirrer.

Preferably, the aging conditions include: the aging temperature is 20-80 ℃, and the aging time is 0.5-18 h.

Further preferably, the aging conditions include: the aging temperature is 25-70 ℃, and the aging time is 1-12 h. In the preferable case, the prepared metal-containing mesoporous molecular sieve is more favorable for obtaining high material conversion rate and product selectivity.

According to an embodiment of the present invention, the method may further include: filtering and washing the aged product to obtain an aged product before the drying in the step (4). The filtration and washing are all operations well known to those skilled in the art, and the present invention is not particularly limited.

The conditions for the drying in step (4) are particularly limited in the present invention, and may be those well known to those skilled in the art. For example, the drying conditions may include: the temperature is 80-180 ℃ and the time is 1-20 hours.

Preferably, the calcination in step (4) is carried out at a temperature of 300-880 ℃, preferably 300-700 ℃, more preferably 400-600 ℃. The selection range of the roasting time is wide, and the roasting time is preferably 1 to 10 hours, more preferably 2 to 6 hours.

According to the present invention, preferably, the method further comprises: introducing acid to adjust the pH in the step (1) and/or the step (2). It should be noted that, in this preferred embodiment, the acid may be introduced separately in step (1) to adjust the pH of the first material, may be introduced separately in step (2) to adjust the pH of the second material, or may be introduced in both step (1) and step (2) to adjust the pH of the first material and the second material. As long as the pH of the material to be aged (the second material) can be adjusted. Preferably, the method further comprises: introducing acid to adjust the pH in the step (2).

The acid may be various acids conventionally used in the art as long as it can function to adjust the pH, and for example, the acid may be at least one of nitric acid, hydrochloric acid, acetic acid, and carbonic acid.

In the conventional preparation method, the hydrolysis rate of the metal source is higher than that of the silicon source under acidic conditions, and the metal source is hydrolyzed into corresponding metal oxide before being combined with the mesoporous molecular sieve, so that the metal source cannot be inserted into the molecular sieve framework. The preparation method of the preferable metal-containing mesoporous molecular sieve provided by the invention overcomes the defects, the addition of the fluorine source influences the occurrence state of the metal atoms, the formation of chemical bonds between the metal atoms and oxygen atoms is reduced, and the generation of metal oxides is avoided. Preferably, the pH of the second material is 1 to 7, more preferably 3 to 6.5. In this preferred case, it is more advantageous to improve the reaction conversion and product selectivity of the resulting metal-containing mesoporous molecular sieve in the production of the cyclic ketoxime.

The present invention will be described in detail below by way of examples.

The reagents used in the following examples are all commercially available chemically pure reagents.

Hydrochloric acid, silicon tetrachloride, Tetraethoxysilane (TEOS) and titanium tetrachloride are analytically pure and purchased from chemical reagents of national drug group, Inc.;

the SBA-15 mesoporous molecular sieve is produced by Hunan Jianchang petrochemical company; MCM-41, HMS, KIT-6 and MCM-48 all-silicon mesoporous molecular sieves were synthesized according to the monograph (Zhao Dongyuan et al, ordered mesoporous molecular sieve materials [ M ]. higher education publishers, 2012).

The UV-Vis characterization map of the metal-containing mesoporous molecular sieve prepared in the preparation example is obtained by characterizing an instrument with the model number of UV-visble550 purchased from JASCO company; the average radial diameter of the particles is measured by a TEM method; the molar ratio of the metal element, the fluorine element and the mesoporous molecular sieve is measured by an XRF method.

The room temperature refers to 25 ℃ without special limitation; atm is a unit of pressure, and 1atm represents 1 standard atmosphere.

In the following preparation examples, the silicon source and the molecular sieve are both used in SiO₂And (6) counting.

Preparation example 1

(1) Mixing a metal source, a fluorine source and a silicon source in an ultrasonic environment to form a colorless transparent solution;

(2) adding the colorless transparent solution into a suspension containing the SBA-15 molecular sieve which is continuously stirred, and then adding 0.1mol/L hydrochloric acid to adjust the pH value to 6.1-6.2; the dosage proportion and the types of the metal source, the fluorine source, the silicon source and the mesoporous molecular sieve are listed in table 1;

(3) continuously stirring and aging the suspension obtained in the step (2) for 2 hours at the temperature of 40 ℃;

(4) and (4) sequentially filtering and washing the product obtained in the step (3) to obtain an aged product, drying at 120 ℃ for 4 hours, and roasting at 550 ℃ for 3 hours to obtain the Ti-SBA-15 mesoporous molecular sieve C-1.

FIG. 1 shows a UV-Vis characterization spectrum of Ti-SBA-15 mesoporous molecular sieve C-1, and it can be seen from FIG. 1 that the molecular sieve has a characteristic peak at a wavelength of 220-230 nm. The characteristic peak positions of the metal-containing mesoporous molecular sieve characterized by UV-Vis are shown in Table 2.

FIG. 3 is a SEM representation of Ti-SBA-15 mesoporous molecular sieve C-1, from which it can be seen that Ti-SBA-15 mesoporous molecular sieve C-1 has a smaller average radial diameter and the average radial diameter of the metal-containing mesoporous molecular sieve is shown in Table 2.

Preparation examples 2 to 12

According to the method of preparation example 1, metal-containing mesoporous molecular sieves C-2 to C-12 were prepared respectively, except that the metal source, fluorine source, silicon source and mesoporous molecular sieve used in step (1) were used in different ratios and kinds and the aging condition in step (3) was different, and the specific conditions of each preparation example are listed in Table 1.

Characteristic peak positions, average radial diameters of metal mesoporous molecular sieves C-2 to C-12, and mesoporous molecular sieves (in terms of SiO)₂Calculated), the molar ratio of fluorine and the modifying metal element are listed in table 2.

TABLE 1

TABLE 2

Preparation of comparative example 1

The Ti-SBA-15 mesoporous molecular sieve material is directly synthesized according to the method reported in the Applied Catalysis A, General,2004,273(1-2), 185-191. TEOS and titanium trichloride are respectively used as a silicon source and a metal titanium source, a triblock copolymer P123 (molecular weight is 5800) is used as a structure directing agent, a concentrated hydrochloric acid aqueous solution is used as an acid source, and the specific synthesis steps are as follows:

(1) 2g P123 was dissolved in 60ml of hydrochloric acid solution at pH 5;

(2) after 4.25g of tetraethyl orthosilicate (TEOS) had been prehydrolyzed at 40 ℃ for a period of time, 0.02g of TiCl was added to the acidic solution with vigorous stirring₃Mixing with 2ml hydrogen peroxide solution, and stirring for 24 hours;

(3) the resulting mixture was statically aged at 60 ℃ for 24 hours;

(4) the resulting aged product was recovered, washed, and dried at 100 ℃ overnight. Calcining for 6h at 550 ℃ in the air to obtain the Ti-SBA-15 mesoporous molecular sieve X.

FIG. 1 shows a UV-Vis characterization spectrum of Ti-SBA-15 mesoporous molecular sieve X, and it can be seen from FIG. 1 that the molecular sieve has no characteristic peak at the wavelength of 220-230 nm. The characteristic peak positions of the metal-containing mesoporous molecular sieve characterized by UV-Vis are shown in Table 2.

FIG. 2 is a SEM characterization of the Ti-SBA-15 mesoporous molecular sieve X, and a comparison of FIGS. 2 and 3 shows that the Ti-SBA-15 mesoporous molecular sieve X has a larger average radial diameter and that the average radial diameter of the metal-containing mesoporous molecular sieve is shown in Table 2.

Preparation of comparative example 2

Ti-MCM-41 was synthesized by microwave hydrothermal method according to the method reported in Journal of Environmental Sciences,2016,44: 76-87. Cationic surfactant Cetyl Trimethyl Ammonium Bromide (CTAB) is used as template agent. Titanium isopropoxide and sodium silicate (Na)₂SiO₃) The method is used as a metal titanium source and a silicon source respectively, and comprises the following specific synthetic steps:

(1) 4.25g CTAB and 5.32g Na were added₂SiO₃Dissolving the two solutions in 30mL and 15mL of deionized water respectively, mixing the two solutions, and then stirring vigorously for 30 minutes at room temperature;

(2) adding 0.45g of titanium isopropoxide into the mixture, stirring for 180min, and adjusting the pH value of the mixed solution to 9.5-10.0 by using 0.1mol/L hydrochloric acid;

(3) heating the mixed solution at 100 ℃ for 180 minutes under the 120W microwave hydrothermal condition, then washing with deionized water and drying;

(4) and sintering the obtained product at 823K for 6 hours to obtain the Ti-MCM-41 molecular sieve Y.

The characteristic peak positions of Ti-MCM-41 molecular sieve Y are shown in Table 2 by the characterization of UV-Vis. The average radial diameter of the metal-containing mesoporous molecular sieve is shown in table 2.

Preparation of comparative example 3

Neutral S was used according to the method reported in the Journal of Molecular Catalysis A: Chemical,2015,397:26-35⁰I⁰Synthesizing the HMS-Ti molecular sieve material by a template method. The process is based on a neutral primary amine surfactant S⁰(dodecylamine) with a neutral inorganic precursor I⁰(tetraethoxysilane: TEOS) hydrogen bond and self-assembly, and mesitylene and tetrabutyl orthotitanate are respectively used as Ti⁴⁺Cationic swelling agent and precursor, filtering the product obtained by the reaction and washing the product with distilled water. Then dried at room temperature for 24h, dried at 100 ℃ for 2h, and then calcined in air at 550 ℃ for 3.5h to obtain HMS-Ti moleculesAnd (4) screening by using a screen Z.

The characteristic peak positions of the HMS-Ti molecular sieve Z characterized by UV-Vis are listed in Table 2. The average radial diameter of the metal-containing mesoporous molecular sieve is shown in table 2.

Example 1

This example is used to illustrate the cyclic ketoxime production method provided by the present invention, and the specific steps include:

(1) adding the catalyst C-1 obtained in the preparation example 1, cyclohexanone, ammonia water (with the concentration of 30 weight percent) and water into a reactor, and mixing under stirring to obtain a mixed material; the weight ratio of cyclohexanone to catalyst to water is 1:0.03:5, and the molar ratio of cyclohexanone to ammonia is 1: 2; the specific material ratios and conditions are listed in table 3.

(2) Introducing 30 wt% aqueous hydrogen peroxide solution into the mixture at a reaction temperature of 60 ℃ for 1h, wherein the molar ratio of cyclohexanone to hydrogen peroxide is 1: 1; continuously reacting for 0.5h after the hydrogen peroxide is added, and controlling the reaction pressure to be 3 atm; the specific material ratios and conditions are listed in table 3.

The reactants and products are analyzed by gas chromatography (Agilent 6890N, HP-5 capillary column 30m 0.25mm 0.25 μm), toluene is used as an internal standard, quantification is carried out by adopting an internal standard method, the content of hydrogen peroxide, cyclohexanone and cyclohexanone oxime in the reaction products is measured, and the data of hydrogen peroxide utilization rate, cyclohexanone conversion rate and cyclohexanone oxime selectivity are respectively obtained by calculation. The data results are shown in Table 4.

Wherein: the conversion of cyclohexanone (amount of raw material cyclohexanone substances-amount of cyclohexanone substances remaining after the reaction)/amount of raw material cyclohexanone substances × 100%;

the cyclohexanone oxime product selectivity is equal to the amount of cyclohexanone oxime substances/(amount of raw material cyclohexanone substances-amount of cyclohexanone substances remaining after the reaction) × 100%;

H₂O₂utilization rate ═ initial H₂O₂Amount of substance-remaining H after reaction₂O₂Amount of material)/initial H₂O₂Amount of substance × 100%.

Examples 2 to 22

The process according to example 1 was followed except that the specific material ratios and conditions were varied, the specific material ratios and conditions are shown in Table 3, and the data results of the hydrogen peroxide utilization, cyclohexanone conversion and cyclohexanone oxime selectivity calculated therefrom are shown in Table 4.

Examples 23 to 33

The procedure of example 1 was followed, except that the catalyst C-1 was replaced with the catalysts C-2 to C-12, respectively. The results of the data on hydrogen peroxide utilization, cyclohexanone conversion and cyclohexanone oxime selectivity are shown in table 4.

Comparative examples 1 to 3

The procedure of example 1 was followed except that the catalysts were replaced with X, Y and Z obtained in preparation of comparative examples 1-3, respectively, and the results of the data calculated for hydrogen peroxide utilization, cyclohexanone conversion and cyclohexanone oxime selectivity are shown in Table 4.

TABLE 3

TABLE 4

The production of the cyclic ketoxime provided by the invention can realize the ammoxidation of macromolecular cyclic ketone, and the method is environment-friendly and has simple and convenient post-treatment. The results of the examples show that when cyclohexanone is oxidized to produce cyclohexanone oxime by using the method provided by the invention, the conversion rate of the reactant and the selectivity of the target product are higher, and the effect is remarkable, wherein the highest utilization rate of hydrogen peroxide can reach 99.9%, the highest conversion rate of the reactant can reach 99.8%, and the highest selectivity of the product cyclohexanone oxime can reach 99.8%.

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.