阅读说明：本技术 一种多相氧化脱硫催化剂及其制备方法 (Heterogeneous oxidation desulfurization catalyst and preparation method thereof ) 是由 陈晓陆 高爽 李振 邓书平 刘海燕 张俊茹 葛登文 张今红 肖舒宁 王珂 何嘉仪 于 2021-07-14 设计创作，主要内容包括：本发明涉及有机化工技术领域,尤其涉及涉及一种多相氧化脱硫催化剂及其制备方法,包括如下步骤：采用水热合成法制备过渡金属修饰的磷钼杂多酸；将疏水基团修饰到介孔材料上得到功能化的载体一；将活性基团修饰到所述载体一上,得到载体二；将所述磷钼杂多酸负载于所述载体二上,得到最终产物。本发明具有以下特点：疏水有机官能基团的引入改善了催化剂的表面环境,减少了多相催化体系中液-固和液-液两相之间的传质阻力,有利于反应物体系的传质；氨基官能基团的引入有利于在载体表面构筑与反应特性相匹配的活性中心及增强活性中心的稳定性；克服了现有技术活性组分稳定性差,反应过程中易发生传质受限的问题,具有高效、稳定的特点。(The invention relates to the technical field of organic chemical industry, in particular to a heterogeneous oxidation desulfurization catalyst and a preparation method thereof, wherein the preparation method comprises the following steps: preparing transition metal modified phosphomolybdic heteropoly acid by a hydrothermal synthesis method; modifying a hydrophobic group on a mesoporous material to obtain a functionalized carrier I; modifying an active group on the carrier I to obtain a carrier II; and loading the phosphomolybdic heteropoly acid on the second carrier to obtain a final product. The invention has the following characteristics: the introduction of the hydrophobic organic functional group improves the surface environment of the catalyst, reduces the mass transfer resistance between liquid-solid and liquid-liquid phases in a heterogeneous catalytic system, and is beneficial to the mass transfer of a reactant system; the introduction of amino functional groups is beneficial to constructing an active center matched with the reaction characteristics on the surface of the carrier and enhancing the stability of the active center; the method overcomes the problems of poor stability of active components and mass transfer limitation easily generated in the reaction process in the prior art, and has the characteristics of high efficiency and stability.)

1. The preparation method of the heterogeneous oxidation desulfurization catalyst is characterized by comprising the following steps of:

preparing transition metal modified phosphomolybdic heteropoly acid by adopting a hydrothermal synthesis method;

modifying a hydrophobic group on a mesoporous material to obtain a functionalized carrier I;

modifying an active group on the carrier I to obtain a carrier II;

and (d) loading the phosphomolybdic heteropoly acid on the second carrier to obtain a final product.

2. The method of claim 1, wherein step (a) further comprises the steps of:

(1) respectively preparing solutions containing phosphate, transition metal salt and molybdate;

(2) mixing and cooling the phosphate and the transition metal salt solution, adjusting the pH value to 0.5-2.5, and dropwise adding concentrated sulfuric acid until the mixed solution is clear to obtain a mixed solution I;

(3) and extracting the mixed solution I by using an organic solvent, separating, and drying at low temperature to obtain the phosphomolybdic heteropoly acid.

3. The method of claim 2, wherein the organic solvent comprises diethyl ether; the drying temperature is 60-100 ℃; the phosphate salt comprises H₂PO₄ ^-、HPO₄ ^2-、PO₄ ^3-(ii) a The transition metal salt comprises Co (NO)₃)₂·6H₂O; the molybdate comprises Na₂MoO₄·H₂O。

4. The method according to claim 1, wherein the steps (b) and (c) further comprise condensing reflux, filtering, Soxhlet extraction and drying under the protection of inert gas; said step (d) further comprises condensing reflux, filtering and drying; the transition metal comprises cobalt; the phosphomolybdic heteropoly acid comprises Keggin type phosphomolybdic heteropoly acid.

5. The method according to claim 4, wherein the temperature of the condensation reflux is 60-80 ℃ and the time is 6-24 h; the Soxhlet extraction time is 8-12 h.

6. The method of claim 5, wherein the temperature of the condensed reflux is 80 ℃; the Soxhlet extraction time is 12 h.

7. The method of claim 1, wherein the hydrophobic group comprises n-octyltrimethoxysilane, isooctyltrimethoxysilane, and alkyltrimethoxysilane having 9 to 16 carbon atoms; the mesoporous material comprises SBA-15; the reactive group comprises 3-aminopropyltriethoxysilane.

8. The method according to claim 1, wherein the hydrothermal reaction temperature in step (a) is 80-110 ℃; the hydrothermal reaction time is 12-24 h.

9. The method of claim 8, wherein the hydrothermal reaction temperature in step (a) is 110 ℃; the hydrothermal reaction time is 24 h.

10. A heterogeneous oxidative desulfurization catalyst, characterized by being prepared according to the method of any one of claims 1 to 9.

Technical Field

The invention relates to the technical field of organic chemical industry, in particular to a heterogeneous oxidative desulfurization catalyst and a preparation method thereof.

Background

In recent years, governments around the world have become increasingly aware of the importance of deep desulfurization of fuel in view of environmental pollution issues. Fossil energy represented by fuel oil is still the most important energy source, but because various sulfur-containing components are left in the petroleum production process, the sulfur elements can seriously corrode pipelines, corrode internal combustion engines and the like during combustion, the service life of the internal combustion engines is shortened, and the combustion products contain a large amount of sulfur dioxide, so that the environment is seriously polluted. Thus, desulfurization of fuel prior to use is the choice for most applications. Methods for desulfurizing fuel oil currently on the market are classified into hydrodesulfurization and non-hydrodesulfurization. The inventor of the invention finds that hydrodesulfurization is the most mature desulfurization technology at present, but hydrodesulfurization limits the application range due to the problems of high production cost, octane number loss and the like, and is not suitable for deep desulfurization; in the non-hydrogen desulfurization process, the oxidation desulfurization technology has the advantages of mild reaction conditions, extremely high removal efficiency for the aromatic heterocyclic sulfide and the like, and has wide practical application prospect; however, the non-hydrogenation catalyst has the problems of difficult separation and recovery of the catalyst, poor stability of active components, easy mass transfer limitation in the reaction process and the like, which greatly limits the wide application of the non-hydrogenation catalyst in the actual industrial production; on the premise of ensuring high performance and low consumption, the development and design of the efficient and stable heterogeneous oxidation desulfurization catalyst have important theoretical significance and industrial application prospect while striving to achieve the aim of environmental protection.

Disclosure of Invention

In order to solve at least one problem mentioned in the background technology, the invention adopts hydrophobic group modification, improves the surface environment of the catalyst, reduces the mass transfer resistance between liquid-solid and liquid-liquid phases in a heterogeneous catalytic system, and is beneficial to the mass transfer high-efficiency mesoporous material and the active component of a reactant system to have good combination stability; the introduction of the active functional group is beneficial to constructing an active center matched with the reaction characteristic on the surface of the carrier and enhancing the stability of the active center.

An object of an embodiment of the present invention is to provide a method for preparing a heterogeneous oxidative desulfurization catalyst, including the steps of:

preparing transition metal modified phosphomolybdic heteropoly acid by adopting a hydrothermal synthesis method;

modifying a hydrophobic group on a mesoporous material to obtain a functionalized carrier I;

modifying an active group on the carrier I to obtain a carrier II;

and (d) loading the phosphomolybdic heteropoly acid on the second carrier to obtain a final product.

The embodiment of the invention also discloses a preparation method of the heterogeneous oxidative desulfurization catalyst, which comprises the following steps:

step (e) preparing transition metal modified phosphomolybdic heteropoly acid by adopting a hydrothermal synthesis method;

modifying a hydrophobic group on the mesoporous material to obtain a functionalized carrier III;

and (g) loading the phosphomolybdic heteropoly acid on the third carrier to obtain a final product B.

The embodiment of the invention also discloses a preparation method of the heterogeneous oxidative desulfurization catalyst, which comprises the following steps:

step (h) preparing transition metal modified phosphomolybdic heteropoly acid by adopting a hydrothermal synthesis method;

step (i), modifying active groups on a mesoporous material to obtain a functionalized carrier IV;

and (j) loading the phosphomolybdic heteropoly acid on the carrier IV to obtain a final product C.

Preferably, the above step (a), step (e) and step (h) further comprise the steps of:

(1) respectively preparing solutions containing phosphate, transition metal salt and molybdate;

(2) mixing and cooling the phosphate and the transition metal salt solution, adjusting the pH value to 0.5-2.5, and dropwise adding concentrated sulfuric acid until the mixed solution is clear to obtain a mixed solution I;

(3) and extracting the mixed solution I by using an organic solvent, separating, and drying at low temperature to obtain the phosphomolybdic heteropoly acid.

Preferably, the organic solvent comprises diethyl ether; the drying temperature is 60-100 ℃; the phosphate salt comprises H₂PO₄ ^-、HPO₄ ^2-、PO₄ ^3-(ii) a The transition metal salt comprises Co (NO)₃)₂·6H₂O; the molybdate comprises Na₂MoO₄·H₂O。

Preferably, the step (b), the step (c), the step (f) and the step (i) further comprise condensing reflux, filtering, Soxhlet extraction and drying under the protection of inert gas; the step (d), the step (g) and the step (j) further comprise refluxing in condensation, filtering and drying.

Preferably, the temperature of the condensation reflux is 60-80 ℃, and the time is 6-24 h; the Soxhlet extraction time is 8-12 h.

Preferably, the temperature of the condensed reflux is 80 ℃; the Soxhlet extraction time is 12 h.

Preferably, the transition metal comprises cobalt; the phosphomolybdic heteropoly acid comprises Keggin type phosphomolybdic heteropoly acid.

Preferably, the hydrophobic group comprises a long chain functional group of 8 to 16 carbon atoms; the mesoporous material comprises SBA-15.

Preferably, the octyl functional group includes n-octyltrimethoxysilane, isooctyltrimethoxysilane, and alkyltrimethoxysilane having 9 to 16 carbon atoms.

Preferably, the mesoporous material comprises SBA-15; the reactive group includes an amino functional group.

Preferably, the amino functional group comprises 3-aminopropyltriethoxysilane.

Preferably, the hydrothermal reaction temperature of the step (a), the step (e) and the step (h) is 80-110 ℃; the hydrothermal reaction time is 12-24 h.

Preferably, the hydrothermal reaction temperature of step (a), step (e) and step (h) is 110 ℃; the hydrothermal reaction time is 24 h.

Preferably, the molar ratio of the phosphate, the transition metal salt, the molybdate, the hydrophobic group and the active group is 0.1-20:0.1-20:0.1-20:0.1-10: 0.1-10.

A heterogeneous oxidative desulfurization catalyst prepared according to the above method; and comprises both a hydrophobic group and a reactive group.

A heterogeneous oxidative desulfurization catalyst prepared according to the above method; containing only hydrophobic groups and no reactive groups.

A heterogeneous oxidative desulfurization catalyst prepared according to the above method; containing only reactive groups and not containing hydrophobic groups.

Advantageous effects

The invention provides a heterogeneous oxidation desulfurization catalyst and a preparation method thereof, and the catalyst has the following characteristics: 1. the introduction of the hydrophobic organic functional group improves the surface environment of the catalyst, reduces the mass transfer resistance between liquid-solid and liquid-liquid phases in a heterogeneous catalytic system, and is beneficial to the mass transfer of a reactant system; 2. the introduction of amino functional groups is beneficial to constructing an active center matched with the reaction characteristics on the surface of the carrier and enhancing the stability of the active center.

Drawings

FIG. 1 is a Fourier Infrared Spectroscopy (FT-IR) of a sample of example 4;

FIG. 2 is a small angle XRD spectrum of the sample of example 4;

FIG. 3 is a wide angle XRD spectrum of a sample of example 4;

FIG. 4 is a thermogravimetric analysis (TG) of example 6;

FIG. 5 is an activity durability analysis of the samples of example 6 and comparative example 1.

Detailed Description

The technical solutions in the embodiments of the present invention are clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the scope of the present invention.

Disclosed herein is a method for preparing a heterogeneous oxidative desulfurization catalyst, comprising the steps of:

preparing transition metal modified phosphomolybdic heteropoly acid by adopting a hydrothermal synthesis method;

modifying a hydrophobic group on a mesoporous material to obtain a functionalized carrier I;

modifying an active group on the carrier I to obtain a carrier II;

and (d) loading the phosphomolybdic heteropoly acid on the second carrier to obtain a final product.

The embodiment of the invention also discloses a preparation method of the heterogeneous oxidative desulfurization catalyst, which comprises the following steps:

step (e) preparing transition metal modified phosphomolybdic heteropoly acid by adopting a hydrothermal synthesis method;

modifying a hydrophobic group on the mesoporous material to obtain a functionalized carrier III;

and (g) loading the phosphomolybdic heteropoly acid on the third carrier to obtain a final product B.

The embodiment of the invention also discloses a preparation method of the heterogeneous oxidative desulfurization catalyst, which comprises the following steps:

step (h) preparing transition metal modified phosphomolybdic heteropoly acid by adopting a hydrothermal synthesis method;

step (i), modifying active groups on a mesoporous material to obtain a functionalized carrier IV;

and (j) loading the phosphomolybdic heteropoly acid on the carrier IV to obtain a final product C.

Preferably, the above step (a), step (e) and step (h) further comprise the steps of:

(1) respectively preparing solutions containing phosphate, transition metal salt and molybdate;

(2) mixing and cooling the phosphate and the transition metal salt solution, adjusting the pH value to 0.5-2.5, and dropwise adding concentrated sulfuric acid until the mixed solution is clear to obtain a mixed solution I;

(3) and extracting the mixed solution I by using an organic solvent, separating, and drying at low temperature to obtain the phosphomolybdic heteropoly acid.

Preferably, the organic solvent comprises diethyl ether; the drying temperature is 60-100 ℃; the phosphate salt comprises H₂PO₄ ^-、HPO₄ ^2-、PO₄ ^3-(ii) a The transition metal salt comprises Co (NO)₃)₂·6H₂O; the molybdate comprises Na₂MoO₄·H₂O; the molar ratio of the phosphate, the transition metal salt, the molybdate, the hydrophobic group and the active group is 0.1-20:0.1-20:0.1-20:0.1-10: 0.1-10.

Preferably, the step (b), the step (c), the step (f) and the step (i) further comprise condensing reflux, filtering, Soxhlet extraction and drying under the protection of inert gas; the step (d), the step (g) and the step (j) further comprise refluxing in condensation, filtering and drying.

Preferably, the temperature of the condensation reflux is 60-80 ℃, and the time is 6-24 h; the Soxhlet extraction time is 8-12 h.

Preferably, the temperature of the condensed reflux is 80 ℃; the Soxhlet extraction time is 12 h.

Preferably, the transition metal comprises cobalt; the phosphomolybdic heteropoly acid comprises Keggin type phosphomolybdic heteropoly acid.

Preferably, the hydrophobic group comprises a long chain functional group of 8 to 16 carbon atoms; the mesoporous material comprises SBA-15.

Preferably, the octyl functional group includes n-octyltrimethoxysilane, isooctyltrimethoxysilane, and alkyltrimethoxysilane having 9 to 16 carbon atoms.

Preferably, the mesoporous material comprises SBA-15; the reactive group includes an amino functional group.

Preferably, the amino functional group comprises 3-aminopropyltriethoxysilane.

Preferably, the hydrothermal reaction temperature of the step (a), the step (e) and the step (h) is 80-110 ℃; the hydrothermal reaction time is 12-24 h.

Preferably, the hydrothermal reaction temperature of step (a), step (e) and step (h) is 110 ℃; the hydrothermal reaction time is 24 h.

A heterogeneous oxidative desulfurization catalyst is disclosed, prepared according to the above-described process; and comprises both a hydrophobic group and a reactive group.

A heterogeneous oxidative desulfurization catalyst is disclosed, prepared according to the above-described process; containing only hydrophobic groups and no reactive groups.

A heterogeneous oxidative desulfurization catalyst is disclosed, prepared according to the above-described process; containing only reactive groups and not containing hydrophobic groups.

In some optional embodiments, the introduction of the hydrophobic organic functional group improves the surface environment of the catalyst, reduces the mass transfer resistance between liquid-solid and liquid-liquid phases in a heterogeneous catalytic system, and is beneficial to mass transfer of a reactant system;

in some alternative embodiments, the introduction of amino functional groups facilitates the construction of active centers on the surface of the support that match the reaction characteristics and enhances the stability of the active centers.

Example 1

On the basis of the disclosed embodiment, a method for preparing a heterogeneous oxidative desulfurization catalyst is disclosed, wherein the step (a), the step (e) and the step (h) further comprise the following steps:

(1) respectively preparing solutions containing phosphate, transition metal salt and molybdate;

(2) mixing and cooling the phosphate and the transition metal salt solution, adjusting the pH value to 0.5, and dropwise adding concentrated sulfuric acid until the mixed solution is clear to obtain a first mixed solution;

(3) and extracting the mixed solution I by using an organic solvent, separating, and drying at low temperature to obtain the phosphomolybdic heteropoly acid.

Preferably, the organic solvent comprises diethyl ether; the drying temperature is 60 ℃; the phosphate is H₂PO₄ ^-、HPO₄ ^2-、PO₄ ^3-(ii) a The transition metal salt is Co (NO)₃)₂·6H₂O; the molybdate is Na₂MoO₄·H₂O。

Preferably, the step (b), the step (c), the step (f) and the step (i) further comprise condensing reflux, filtering, Soxhlet extraction and drying under the protection of inert gas; the step (d), the step (g) and the step (j) further comprise refluxing in condensation, filtering and drying.

Preferably, the temperature of the condensation reflux is 60 ℃ and the time is 6 h; the Soxhlet extraction time is 8 h.

Preferably, the transition metal comprises cobalt; the phosphomolybdic heteropoly acid comprises Keggin type phosphomolybdic heteropoly acid.

Preferably, the hydrophobic group is a long chain functional group of 8 carbon atoms; the mesoporous material is SBA-15.

Preferably, the octyl functional group is n-octyltrimethoxysilane.

Preferably, the mesoporous material comprises SBA-15; the reactive group includes an amino functional group.

Preferably, the amino functional group comprises 3-aminopropyltriethoxysilane.

Preferably, the hydrothermal reaction temperature of step (a), step (e) and step (h) is 80 ℃; the hydrothermal reaction time is 12-24 h.

Preferably, the hydrothermal reaction temperature of step (a), step (e) and step (h) is 80 ℃; the hydrothermal reaction time is 24 h.

Preferably, the molar ratio of the phosphate salt, the transition metal salt, the molybdate salt, the hydrophobic group and the active group is 0.1:0.1:0.1: 0.1.

A heterogeneous oxidative desulfurization catalyst is disclosed, prepared according to the above-described process; and comprises both a hydrophobic group and a reactive group.

A heterogeneous oxidative desulfurization catalyst is disclosed, prepared according to the above-described process; containing only hydrophobic groups and no reactive groups.

A heterogeneous oxidative desulfurization catalyst is disclosed, prepared according to the above-described process; containing only reactive groups and not containing hydrophobic groups.

In some optional embodiments, the introduction of the hydrophobic organic functional group improves the surface environment of the catalyst, reduces the mass transfer resistance between liquid-solid and liquid-liquid phases in a heterogeneous catalytic system, and is beneficial to mass transfer of a reactant system;

in some alternative embodiments, the introduction of amino functional groups facilitates the construction of active centers on the surface of the support that match the reaction characteristics and enhances the stability of the active centers.

Example 2

On the basis of the disclosed embodiment, a method for preparing a heterogeneous oxidative desulfurization catalyst is disclosed, wherein the step (a), the step (e) and the step (h) further comprise the following steps:

(1) respectively preparing solutions containing phosphate, transition metal salt and molybdate;

(2) mixing and cooling the phosphate and the transition metal salt solution, adjusting the pH value to 2.5, and dropwise adding concentrated sulfuric acid until the mixed solution is clear to obtain a first mixed solution;

(3) and extracting the mixed solution I by using an organic solvent, separating, and drying at low temperature to obtain the phosphomolybdic heteropoly acid.

Preferably, the organic solvent comprisesDiethyl ether; the drying temperature is 100 ℃; the phosphate salt comprises H₂PO₄ ^-、HPO₄ ^2-、PO₄ ^3-(ii) a The transition metal salt comprises Co (NO)₃)₂·6H₂O; the molybdate comprises Na₂MoO₄·H₂O。

Preferably, the step (b), the step (c), the step (f) and the step (i) further comprise condensing reflux, filtering, Soxhlet extraction and drying under the protection of inert gas; the step (d), the step (g) and the step (j) further comprise refluxing in condensation, filtering and drying.

Preferably, the temperature of the condensation reflux is 80 ℃, and the time is 24 h; the Soxhlet extraction time is 12 h.

Preferably, the transition metal comprises cobalt; the phosphomolybdic heteropoly acid comprises Keggin type phosphomolybdic heteropoly acid.

Preferably, the hydrophobic group is a long chain functional group of 16 carbon atoms; the mesoporous material is SBA-15.

Preferably, the octyl functional group is n-16 alkyl trimethoxysilane.

Preferably, the mesoporous material is SBA-15; the active group is 3-aminopropyl triethoxysilane.

Preferably, the hydrothermal reaction temperature of step (a), step (e) and step (h) is 110 ℃; the hydrothermal reaction time is 12-24 h.

Preferably, the molar ratio of the phosphate, the transition metal salt, the molybdate, the hydrophobic group and the active group is 20:20:20:10: 10.

A heterogeneous oxidative desulfurization catalyst is disclosed, prepared according to the above-described process; and comprises both a hydrophobic group and a reactive group.

A heterogeneous oxidative desulfurization catalyst is disclosed, prepared according to the above-described process; containing only hydrophobic groups and no reactive groups.

A heterogeneous oxidative desulfurization catalyst is disclosed, prepared according to the above-described process; containing only reactive groups and not containing hydrophobic groups.

In some optional embodiments, the introduction of the hydrophobic organic functional group improves the surface environment of the catalyst, reduces the mass transfer resistance between liquid-solid and liquid-liquid phases in a heterogeneous catalytic system, and is beneficial to mass transfer of a reactant system;

in some alternative embodiments, the introduction of amino functional groups facilitates the construction of active centers on the surface of the support that match the reaction characteristics and enhances the stability of the active centers.

Example 3

On the basis of the disclosed embodiment, a method for preparing a heterogeneous oxidative desulfurization catalyst is disclosed, wherein the step (a), the step (e) and the step (h) further comprise the following steps:

(1) respectively preparing solutions containing phosphate, transition metal salt and molybdate;

(2) mixing and cooling the phosphate and the transition metal salt solution, adjusting the pH value to 1.5, and dropwise adding concentrated sulfuric acid until the mixed solution is clear to obtain a first mixed solution;

(3) and extracting the mixed solution I by using an organic solvent, separating, and drying at low temperature to obtain the phosphomolybdic heteropoly acid.

Preferably, the organic solvent comprises diethyl ether; the drying temperature is 80 ℃; the phosphate salt comprises H₂PO₄ ^-、HPO₄ ^2-、PO₄ ^3-(ii) a The transition metal salt comprises Co (NO)₃)₂·6H₂O; the molybdate comprises Na₂MoO₄·H₂O。

Preferably, the step (b), the step (c), the step (f) and the step (i) further comprise condensing reflux, filtering, Soxhlet extraction and drying under the protection of inert gas; the step (d), the step (g) and the step (j) further comprise refluxing in condensation, filtering and drying.

Preferably, the temperature of the condensation reflux is 70 ℃, and the time is 12 h; the Soxhlet extraction time is 10 h.

Preferably, the transition metal is cobalt; the phosphomolybdic heteropoly acid is Keggin type phosphomolybdic heteropoly acid.

Preferably, the hydrophobic group is a long chain functional group of 12 carbon atoms; the mesoporous material is SBA-15.

Preferably, the octyl functional group is n-dodecyltrimethoxysilane.

Preferably, the active group is 3-aminopropyltriethoxysilane.

Preferably, the hydrothermal reaction temperature of step (a), step (e) and step (h) is 90 ℃; the hydrothermal reaction time is 18 h.

Preferably, the molar ratio of the phosphate salt, the transition metal salt, the molybdate salt, the hydrophobic group and the active group is 5:3:2:3: 4.

A heterogeneous oxidative desulfurization catalyst is disclosed, prepared according to the above-described process; and comprises both a hydrophobic group and a reactive group.

A heterogeneous oxidative desulfurization catalyst is disclosed, prepared according to the above-described process; containing only hydrophobic groups and no reactive groups.

A heterogeneous oxidative desulfurization catalyst is disclosed, prepared according to the above-described process; containing only reactive groups and not containing hydrophobic groups.

In some optional embodiments, the introduction of the hydrophobic organic functional group improves the surface environment of the catalyst, reduces the mass transfer resistance between liquid-solid and liquid-liquid phases in a heterogeneous catalytic system, and is beneficial to mass transfer of a reactant system;

in some alternative embodiments, the introduction of amino functional groups facilitates the construction of active centers on the surface of the support that match the reaction characteristics and enhances the stability of the active centers.

Example 4

On the basis of the disclosed embodiment, a heterogeneous oxidation desulfurization catalyst and a preparation method thereof are disclosed, wherein the preparation method comprises the following steps:

(1) mixing Na₂HPO₄·H₂Dissolving O (0.005mol) in 10ml of distilled water to prepare a solution 1; mixing Co (NO)₃)₂·6H₂Dissolving O (0.005mol) in 10ml of boiling water to prepare a solution 2; mixing Na₂MoO₄·H₂Dissolving O (0.055mol) in 20ml of distilled water to obtain a solution 3; mixing solution 1 and solutionAnd (3) cooling the solution 2, dropwise adding concentrated sulfuric acid, acidifying until the pH value is about 1.5, mixing with the solution 3, and dropwise adding the concentrated sulfuric acid into the mixed solution under vigorous stirring until the mixed solution is clear. Extracting heteropolyacid with equal amount of diethyl ether in fume hood, separating, placing lower layer yellow clear oily substance in beaker, heating in 100 deg.C water bath to obtain yellow green solid PMo₁₁Co。

(2) 2mmol of N-octyltrimethoxysilane (-octyl) were added to a 35m L toluene suspension containing 1.0g of SBA-15, and the mixture was stirred under N₂Refluxing for 24h under protection. Filtering, soxhlet extracting with toluene for 12h, and vacuum drying to obtain octyl-SBA-15;

(3) 2mmol of 3-aminopropyltriethoxysilane were added to 35mL of a toluene suspension containing 1.0g of octyl-SBA-15 in N₂Stirring and refluxing for 24h under protection. Filtering, soxhlet extracting with toluene for 12h, and vacuum drying to obtain octyl-NH₂-SBA-15；

(4) 30ml of methanol is added into a 100ml three-neck flask, and a certain amount of octyl-NH is added₂SBA-15 and PMo₁₁Co was added to the flask and stirred at 80 ℃ for 24h under reflux. Washed several times with methanol and dried in vacuo for 12h, denoted PMo₁₁Co-octyl-NH₂-SBA-15。

Example 5

On the basis of the disclosed embodiment, a heterogeneous oxidation desulfurization catalyst and a preparation method thereof are disclosed, wherein the preparation method comprises the following steps:

(1) mixing Na₂HPO₄·H₂Dissolving O (0.005mol) in 10ml of distilled water to prepare a solution 1; mixing Co (NO)₃)₂·6H₂Dissolving O (0.005mol) in 10ml of boiling water to prepare a solution 2; mixing Na₂MoO₄·H₂Dissolving O (0.055mol) in 20ml of distilled water to obtain a solution 3; mixing the solution 1 and the solution 2, cooling, dropwise adding concentrated sulfuric acid, acidifying until the pH value is about 1.5, mixing with the solution 3, and dropwise adding concentrated sulfuric acid into the mixed solution under vigorous stirring until the mixed solution is clear. Extracting heteropolyacid with equal amount of diethyl ether in fume hood, separating, placing lower layer yellow clear oily substance in beaker, heating in 100 deg.C water bath to obtain yellow green solid PMo₁₁Co。

(2) 2m ismol N-octyltrimethoxysilane (-octyl) was added to 35m L toluene suspension containing 1.0g of SBA-15, and the mixture was stirred under N₂Refluxing for 24h under protection. Filtering, soxhlet extracting with toluene for 12h, and vacuum drying to obtain octyl-SBA-15;

(3) 30ml of methanol was charged into a 100ml three-necked flask, and a certain amount of octyl-SBA-15 and PMo were added₁₁Co was added to the flask and stirred at 80 ℃ for 24h under reflux. Washed several times with methanol and dried in vacuo for 12h, denoted PMo₁₁Co-octyl-SBA-15。

Example 6

On the basis of the disclosed embodiment, a heterogeneous oxidation desulfurization catalyst and a preparation method thereof are disclosed, wherein the preparation method comprises the following steps:

(1) mixing Na₂HPO₄·H₂Dissolving O (0.005mol) in 10ml of distilled water to prepare a solution 1; mixing Co (NO)₃)₂·6H₂Dissolving O (0.005mol) in 10ml of boiling water to prepare a solution 2; mixing Na₂MoO₄·H₂Dissolving O (0.055mol) in 20ml of distilled water to obtain a solution 3; mixing the solution 1 and the solution 2, cooling, dropwise adding concentrated sulfuric acid, acidifying until the pH value is about 1.5, mixing with the solution 3, and dropwise adding concentrated sulfuric acid into the mixed solution under vigorous stirring until the mixed solution is clear. Extracting heteropolyacid with equal amount of diethyl ether in fume hood, separating, placing lower layer yellow clear oily substance in beaker, heating in 100 deg.C water bath to obtain yellow green solid PMo₁₁Co。

(2) 2mmol of 3-aminopropyltriethoxysilane were added to a 35mL toluene suspension containing 1.0g of SBA-15 in N₂Stirring and refluxing for 24h under protection. Filtering, toluene Soxhlet extraction for 12h, and vacuum drying to obtain NH₂-SBA-15；

(3) 30ml of methanol was charged into a 100ml three-necked flask, and a certain amount of NH was added₂SBA-15 and PMo₁₁Co was added to the flask and stirred at 80 ℃ for 24h under reflux. Washed several times with methanol and dried in vacuo for 12h, denoted PMo₁₁Co-NH₂-SBA-15。

Comparative example 1

Based on the disclosed examples, a catalyst free of hydrophobic groups and active groups was prepared using the protocol disclosed in example 1 for comparison and to compare with the prior art, the remainder being the same as in example 4.

Results and analysis

Characterization analysis was performed on the catalysts prepared by the methods disclosed in example 4 and comparative example 1:

EXAMPLE 4 Fourier Infrared Spectroscopy (FT-IR) of samples

As can be seen from FIG. 1, SBA-15 is 1058cm^-1Absorption peaks appearing at wave numbers are attributed to the asymmetric stretching vibration of Si-O-Si; 460cm^-1The absorption peaks appearing at wave numbers are attributed to the bending vibration of Si-O-Si; at 810cm^-1Absorption peaks appearing at wave numbers are attributed to the symmetric stretching vibration of Si-O-Si; at 3410cm^-1A wider absorption peak appears at wave number, which is attributed to Si-OH and adsorbed H₂Stretching and contracting of-O-H bond in O. NH (NH)₂SBA-15 at 692cm^-1And 1560cm^-1A new absorption peak appears at wave number, and the peak is assigned to-NH₂Flexural vibration of the Medium-N-H bond, Explanation of-NH₂The group was smoothly attached to the SBA-15 surface. in-octyl-NH₂In the FT-IR spectrum of SBA-15, some new absorption peaks also appear. At 2929cm^-1And 2851cm^-1Two absorption peaks at wave number, which are respectively assigned to-CH₂Asymmetric and symmetric stretching vibration of-at 1463cm^-1An absorption peak at wavenumber, attributed to bending vibration of the-C-H-bond, appeared indicating that the hydrophobic group octyl group had been successfully grafted onto the surface of the support SBA-15.

EXAMPLE 4 sample X-ray powder diffraction (XRD)

Figures 2 and 3 are small and wide angle XRD spectra of different samples. SBA-15 and NH in FIG. 3₂SBA-15 shows three diffraction peaks at 0.8 degrees, 1.5 degrees and 1.7 degrees, which are respectively assigned to the (100), (110) and (200) crystal planes. The appearance of the diffraction peak indicates that the synthesized SBA-15 has a regular two-dimensional hexagonal structure, and the synthesis of the SBA-15 is successful. -NH-in contrast to SBA-15₂-SBA-15 and-octyl-NH₂The decrease in the diffraction peaks of the crystal plane of SBA-15 indicates the successful introduction of the unit into the pore channels of SBA-15. wherein-octyl-NH₂Diffraction of SBA-15 in the (110) and (200) crystal planesThe peak drop was most severe, indicating that the phosphomolybdic heteropolyacids Co-POM units, -octyl groups and-NH₂The introduction of the group causes a certain degree of damage to the long-range order of the SBA-15 pore channel structure. In the wide-angle XRD spectrum of fig. 4, it can be seen that each catalyst shows a wider typical diffraction peak of the mesoporous molecular sieve at 2 θ ═ 15-30 °, and no characteristic peak of heteropolyacid attributed to the unit is observed, indicating that Co-POM unit is uniformly distributed in the pore channel of mesoporous SBA-15.

For the oxidation desulfurization reaction, the reaction is carried out in a liquid (oil phase) -liquid (extraction phase) -solid (catalyst) three-phase reaction system, and because mass transfer resistance exists among reactants, the control or adjustment of the chemical property of the surface of the solid catalyst becomes the key for improving the catalytic activity. The long-chain organic group (octyl) can enable the catalyst to have a more hydrophobic surface, and the more hydrophobic surface environment can accelerate the diffusion of reactants to an active center, so that the catalytic activity is improved.

EXAMPLE 6 thermogravimetric analysis (TG)

As shown in FIG. 4, -NH₂Introduction of-SBA-15 sample into-NH₂The thermal weight loss after the radical changes, which shows that the above step can be used for converting-NH₂The group is introduced into the mesoporous material.

Example 6 and comparative example 1 samples Activity durability analysis

Comparative example 1 no-NH after 5 cycles as shown in FIG. 5₂The desulfurization rate of the functionalized-SBA-15 is greatly reduced to 65.31 percent, compared with that of the sample-NH of example 6₂The desulfurization rate of-SBA-15 is substantially stable, which is mainly attributed to-NH₂The introduction of the groups reduces the number of Si-OH groups on the surface of the carrier, and active component units and newly increased-NH₂The groups can form strong electrostatic attraction force, the interaction force is stronger than that of Si-OH groups, and the unit and-NH are enabled₂The groups are easier to form a stable structure, so the activity of the catalyst is still not obviously reduced after 5 times of recycling.

It will be understood by those of ordinary skill in the art that the foregoing embodiments are specific examples for carrying out the invention, and that various changes in form and details may be made therein without departing from the spirit and scope of the invention in practice.