CN115888819B - Preparation method of nano-aluminum oxide hybrid modified styrene-divinylbenzene copolymer hydrophobic catalyst carrier - Google Patents

Abstract

In order to solve the problem of lower compressive strength of the existing SDB hydrophobic catalyst carrier, the invention discloses a preparation method of a nano aluminum oxide hybridization modified styrene-divinylbenzene copolymer hydrophobic catalyst carrier, which comprises the following steps: the heptadecafluorodecyl trimethoxy silane, nano aluminum oxide and ethanol react to obtain modified nano aluminum oxide; preparing an aqueous phase; mixing styrene, divinylbenzene, benzoyl peroxide, modified nano aluminum oxide and the like to obtain an oil phase; suspension polymerization is carried out to obtain the nano aluminum oxide hybridized modified styrene-divinylbenzene copolymer hydrophobic catalyst carrier. According to the preparation method, nano aluminum oxide modified by heptadecafluorodecyl trimethoxy silane is introduced, and the compressive strength and the hydrophobicity of the SDB hydrophobic catalyst carrier are greatly improved through the excellent mechanical properties of the inorganic nano particles, and the SDB hydrophobic catalyst carrier has a larger particle size.

Description

Preparation method of nano-aluminum oxide hybrid modified styrene-divinylbenzene copolymer hydrophobic catalyst carrier

Technical Field

The invention relates to catalyst technology, in particular to a method for preparing a nano-aluminum oxide hybrid modified styrene-divinylbenzene copolymer hydrophobic catalyst carrier.

Background Art

Nuclear power generation has developed rapidly due to its high and stable power supply efficiency and the fact that it does not emit sulfur oxides, greenhouse gases and nitrogen oxides like traditional fossil fuels. However, with the development of nuclear power generation, the discharge of tritium-containing wastewater is also increasing, and these tritium-containing wastewater cannot be treated by conventional three-waste systems.

From the perspective of economy and safety, hydrogen-water liquid phase catalytic exchange technology (LPCE) is one of the most effective methods for treating tritium-containing wastewater. The key material of LPCE technology is the hydrophobic catalyst, which is composed of a catalyst carrier and an active component. There are two commonly used hydrophobic catalysts, namely hydrophobic catalysts with polytetrafluoroethylene (PTFE) as a carrier and hydrophobic catalyst carriers with styrene-divinylbenzene copolymer (SDB) as a carrier.

For example, the Chinese invention patent application (CN113019464A) discloses a method for preparing a size-controllable spherical SDB hydrophobic carrier and a Pt/SDB hydrophobic catalyst, and specifically discloses that the preparation method of the Pt/SDB hydrophobic catalyst includes the following steps: mixing a determined ratio of styrene and divinylbenzene polymerization monomers, a polymerization initiator benzoyl peroxide, a determined ratio of a mixed porogen of toluene and n-heptane, and a density regulator to obtain an organic phase; prepolymerizing the mixed organic phase in a low surface tension aqueous solution at low temperature to cause droplet aggregation, then heating to initiate a polymerization reaction to obtain a spherical SDB hydrophobic carrier crude product, extracting with acetone, and then using mechanical grinding physical etching and oxidizing acid oxidation chemical etching to achieve surface roughening, washing and drying to obtain a spherical SDB hydrophobic carrier, loading the active component on the surface of the carrier by an impregnation method, and then obtaining a Pt/SDB hydrophobic catalyst by high-temperature hydrogenation reduction. According to the catalytic gas phase H-D exchange test, the efficiency of the Pt/SDB hydrophobic catalyst can reach more than 94%.

However, the existing SDB hydrophobic catalyst carrier also has low compressive strength and needs to be improved urgently.

Summary of the invention

The present invention solves the problem of low compressive strength of the existing SDB hydrophobic catalyst carrier and provides a method for preparing a nano-aluminum trioxide hybrid modified styrene-divinylbenzene copolymer hydrophobic catalyst carrier. In the preparation method, nano-aluminum trioxide modified by heptadecafluorodecyltrimethoxysilane is introduced, and the compressive strength and hydrophobicity of the SDB hydrophobic catalyst carrier are greatly improved by the excellent mechanical properties of the inorganic nanoparticles themselves, and the particle size is larger.

The technical solution adopted by the present invention is:

The preparation method of a nano-aluminum oxide hybrid modified styrene-divinylbenzene copolymer hydrophobic catalyst carrier comprises the following steps:

Step S1, mixing heptadecafluorodecyltrimethoxysilane (HFTMS), nano-aluminum trioxide (nano-Al ₂ O ₃ ) and ethanol in a predetermined ratio to obtain modified nano-aluminum trioxide after reaction;

Step S2, mixing hydroxymethyl cellulose, sodium dodecylbenzene sulfonate, polyvinyl alcohol 1788 and water according to a predetermined ratio to obtain an aqueous phase;

Step S3, mixing styrene, divinylbenzene, benzoyl peroxide and modified nano-aluminum oxide, as well as toluene, n-heptane and ethylene dichloride according to a predetermined ratio to obtain an oil phase;

Step S4, according to the preset reaction conditions, add all the oil phase into the water phase for suspension polymerization, and after the reaction, filter, dry and sieve to obtain the nano-aluminum trioxide hybrid modified styrene-divinylbenzene copolymer hydrophobic catalyst carrier (HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst carrier).

Furthermore, in step S1, heptadecafluorodecyltrimethoxysilane, nano-aluminum oxide and ethanol are mixed according to a predetermined ratio, and the specific process of obtaining modified nano-aluminum oxide after reaction includes:

Step S11, mixing heptadecafluorodecyltrimethoxysilane and ethanol in a volume ratio of 1:100 to obtain a modifier dilution solution;

Step S12, according to the weight ratio of 17fluorodecyltrimethoxysilane to nano-aluminum oxide of 0.2-0.5:1, adding nano-aluminum oxide to the modifier dilution solution for reaction, controlling the reaction temperature to 50-60°C, the reaction time to 4-6 hours, and after the reaction is completed, washing with anhydrous ethanol and water in sequence, and drying to obtain modified nano-aluminum oxide.

Furthermore, in the step S12, the weight ratio of heptadecafluorodecyltrimethoxysilane to nano-aluminum oxide is 0.35:1, the reaction temperature is controlled at 70° C., and the reaction time is 4 hours.

Furthermore, in step 12, when washing with anhydrous ethanol and water, the amount of anhydrous ethanol and water used is 10 to 20 times the volume of heptadecafluorodecyltrimethoxysilane respectively;

And/or, in step S12, vacuum drying is adopted during drying, the drying temperature is 70-80° C., and the drying time is 3-4 hours.

Furthermore, in step S2, the amount of each raw material in the aqueous phase is calculated by weight:

Hydroxymethyl cellulose, 0.1-0.3 parts;

Sodium dodecylbenzenesulfonate, 0.1-0.4 parts;

Polyvinyl alcohol 1788, 2-4 parts;

Water, 200-400 parts.

Furthermore, in step S2, the water phase mixing temperature is 70-80° C., and the mixing time is 1-2 hours.

Furthermore, in step S3, the amount of each raw material of the oil phase is calculated by weight:

Styrene, 2-10 parts;

Divinylbenzene, 2-10 parts;

Benzoyl peroxide, 0.1~0.6 parts;

Modified nano-aluminum oxide, 0.01~2 parts;

Toluene, 1-16 parts;

n-heptane, 12-24 parts;

Ethylene dichloride, 5-12 parts.

Furthermore, in step S3, the mass ratio of styrene, divinylbenzene and modified nano-aluminum oxide is 10:10:0.05-0.2.

Furthermore, in step S3, the oil phase is firstly ultrasonically mixed for 30 minutes.

Furthermore, in step S4, during suspension polymerization, the reaction temperature is controlled to be 90-95° C. and the reaction time is 7-8 h;

And/or, in step S4, the drying temperature is 60-70° C., and the drying time is 5-6 hours.

The beneficial effects of the present invention are:

1. In order to improve the strength of the SDB hydrophobic catalyst carrier, the present invention uses styrene as a monomer, divinylbenzene as a crosslinking agent, benzoyl peroxide as an initiator, n-heptane as a porogen, 1,2-dichloroethane as a solubilizer, modified nano-aluminum trioxide as a modified functional monomer, polyvinyl alcohol 1788 as an organic polymer dispersant, and sodium dodecylbenzene sulfonate and hydroxymethyl cellulose as dispersants. The present invention utilizes the synergistic effect between polyvinyl alcohol 1788, sodium dodecylbenzene sulfonate and hydroxymethyl cellulose, and utilizes the selected functional monomer HFTMS to introduce a -CF group on the surface of nano-Al ₂ O ₃ to improve the hydrophobicity of nano-Al ₂ O ₃ , so that the modified nano-Al ₂ O ₃ (HFTMS-Al ₂ O ₃ ) can be better dispersed in the oil phase. At the same time, the introduced modified nano-Al ₂ O ₃ (HFTMS-Al ₂ O ₃ ) itself has excellent mechanical properties, which can greatly improve the compressive properties and hydrophobicity of the HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst carrier.

2. The present invention adopts a suspension polymerization method, which is simple, easy to operate and highly practical. The materials are added in a one-time ratio, which is easy to form stable and uniform oil droplets. At the same time, modified polymerization monomers styrene and divinylbenzene with suitable reactivity ratios and modified nano-Al ₂ O ₃ are selected as the third functional monomer to achieve suspension polymerization ternary copolymerization and synthesize HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst carrier with large specific surface area and suitable pore size and pore volume. The hydrophobic angle of the HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst carrier can reach 147°, the compressive strength can reach 132N, and the particle size is 2-3mm.

3. The HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst carrier prepared in the present invention has a high loading stability for catalytically active components (i.e., it can provide loading active sites, etc.), can improve the catalytic performance of the catalyst, and has the advantages of reducing the mass transfer resistance of the bed, preventing flooding, and improving the fluid exchange efficiency, etc. The metal-supported catalyst (such as Pt/SDB hydrophobic catalyst) prepared with the HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst carrier prepared in the present invention can be used for engineering applications such as detritium extraction from heavy water and detritium removal from wastewater, has high catalytic efficiency, excellent hydrophobic stability, can be used at room temperature, and has good use effect.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

FIG. 1 is a diagram showing the static contact angle test results of the HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst support in Example 17. FIG.

FIG. 2 is a scanning electron microscope image of the HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst support in Example 17.

FIG. 3 is a diagram showing infrared detection results of the HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst support in Example 17. FIG.

FIG. 4 is a graph showing the thermogravimetric results of the HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst support in Example 17.

FIG. 5 is an elemental analysis diagram of the HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst support in Example 17.

DETAILED DESCRIPTION

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

The disclosure below provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention.

The embodiments of the invention are described in detail below with reference to the accompanying drawings.

The preparation method of a nano-aluminum oxide hybrid modified styrene-divinylbenzene copolymer hydrophobic catalyst carrier comprises the following steps:

Step S1, mixing heptadecafluorodecyltrimethoxysilane (HFTMS), nano-aluminum trioxide (nano-Al ₂ O ₃ ) and ethanol in a predetermined ratio, and obtaining modified nano-aluminum trioxide (modified nano-Al ₂ O _{3 )} after reaction;

Step S2, mixing hydroxymethyl cellulose, sodium dodecylbenzene sulfonate, polyvinyl alcohol 1788 and water according to a predetermined ratio to obtain an aqueous phase;

Step S3, mixing styrene, divinylbenzene, benzoyl peroxide and modified nano-aluminum oxide, as well as toluene, n-heptane and ethylene dichloride according to a predetermined ratio to obtain an oil phase;

Step S4, according to the preset reaction conditions, all the oil phase is added to the water phase for suspension polymerization. After the reaction is completed, the nano-aluminum trioxide hybrid modified styrene-divinylbenzene copolymer hydrophobic catalyst carrier (HFTMS-Al2O3/SDB hydrophobic catalyst carrier) is obtained by filtration, drying and sieving.

Furthermore, in step S1, heptadecafluorodecyltrimethoxysilane, nano-aluminum oxide and ethanol are mixed according to a predetermined ratio, and the specific process of obtaining modified nano-aluminum oxide after reaction includes:

Step S11, mixing heptadecafluorodecyltrimethoxysilane and ethanol in a volume ratio of 1:100 to obtain a modifier dilution solution;

Step S12, according to the weight ratio of 17fluorodecyltrimethoxysilane to nano-aluminum trioxide (nano-Al2O3) of 0.2~0.5:1, add nano-aluminum trioxide to the modifier dilution solution for reaction, control the reaction temperature to 50~60°C, the reaction time to 4~6h, after the reaction is completed, wash with anhydrous ethanol and water in turn, and dry to obtain modified nano-aluminum trioxide.

Furthermore, in the step S12, the weight ratio of heptadecafluorodecyltrimethoxysilane to nano-aluminum oxide is 0.35:1, the reaction temperature is controlled at 70° C., and the reaction time is 4 hours.

Furthermore, in step 12, when washing with anhydrous ethanol and water, the amount of anhydrous ethanol and water used is 10 to 20 times the volume of heptadecafluorodecyltrimethoxysilane respectively;

And/or, in step S12, vacuum drying is adopted during drying, the drying temperature is 70-80° C., and the drying time is 3-4 hours.

Furthermore, in step S2, the amount of each raw material in the aqueous phase is calculated by weight:

Hydroxymethyl cellulose, 0.1-0.3 parts;

Sodium dodecylbenzenesulfonate, 0.1-0.4 parts;

Polyvinyl alcohol 1788, 2-4 parts;

Water (distilled or deionized), 200-400 parts.

Furthermore, in step S2, the water phase mixing temperature is 70-80° C., and the mixing time is 1-2 hours.

Furthermore, in step S3, the amount of each raw material of the oil phase is as follows, in parts by weight:

Styrene, 2-10 parts;

Divinylbenzene, 2-10 parts;

Benzoyl peroxide, 0.1~0.6 parts;

Modified nano-aluminum oxide, 0.01~2 parts;

Toluene, 1-16 parts;

n-heptane, 12-24 parts;

Ethylene dichloride, 5-12 parts.

Furthermore, in step S3, the mass ratio of styrene, divinylbenzene and modified nano-aluminum oxide is 10:10:0.05-0.2.

Furthermore, in step S3, the oil phase is firstly ultrasonically mixed for 30 minutes.

Furthermore, in step S4, during suspension polymerization, the reaction temperature is controlled to be 90-95° C. and the reaction time is 7-8 h;

And/or, in step S4, the drying temperature is 60-70° C., and the drying time is 5-6 hours.

The present application is described in detail below through specific examples. In order to obtain a HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst carrier with excellent performance, the inventors conducted the following research.

(1) Research on modification of nano-aluminum oxide

The particle size of nano-Al ₂ O ₃ is 20nm. It is easy to cause powder agglomeration due to the intermolecular force. When it is directly added to the oil phase, there will be a problem of poor dispersibility. Therefore, the inventors conducted relevant tests and research on the modification process of nano-aluminum oxide, and tested the static contact angle (hydrophobic angle) of the modified nano-Al ₂ O ₃ .

The preparation process of modified nano-alumina in Examples 1 to 5 is as follows: 0.5 g of KH560, KH570, stearic acid, 13-fluorooctyl trimethoxysilane (PFOTMS) and 17-fluorodecyl trimethoxysilane (HFTMS) are used as modifiers, and the modifiers and ethanol are mixed in a volume ratio of 1:100 to obtain a modifier dilution; wherein, stearic acid is solid at room temperature, so it is converted into the corresponding weight and then configured. 1 g of nano-Al 2 O ₃ is added to the modifier dilution, the reaction temperature is controlled to be 50°C, the reaction time is 5h, and after the reaction is completed, anhydrous ethanol and water are washed in turn, and dried to obtain modified nano-Al ₂ O _3. The test results of the modified nano-Al _{2 O 3} prepared in Examples 1 to 5 are shown in Table 1 below.

Control Example 1 is to test the initial unmodified nano-aluminum oxide without any treatment in the same test method.

Table 1 Static contact angle test results of modified nano-Al ₂ O ₃ in Examples 1 to 5

From the test results of Examples 1 to 5 in Table 1, it can be seen that KH560, KH570, stearic acid, PFOTMS and HFTMS can all significantly improve the hydrophobicity of nano-Al ₂ O _3. The hydrophobic modification effects of KH560, KH570, stearic acid, PFOTMS and HFTMS on nano-Al ₂ O ₃ are better than those of KH560, KH570 and stearic acid on nano-Al ₂ O _3. The inventors analyzed that the reason is that HFTMS and PFOTMS introduce CF bonds into nano-Al ₂ O ₃ through their own chemical structures, thereby improving the hydrophobicity of nano-Al ₂ O ₃ .

At the same time, the hydrophobic modification effect of HFTMS on nano-Al ₂ O ₃ is better than that of PFOTMS. The inventors analyzed that the reason is that HFTMS contains more CF bonds than PFOTMS, so the modification effect of HFTMS on nano-Al ₂ O ₃ is more advantageous. In addition, when the inventors placed HFTMS and PFOTMS modified nano-Al ₂ O ₃ in oil phase (mixed liquids such as styrene, divinylbenzene, toluene, dichloroethane, and n-heptane), the sedimentation stability of HFTMS modified nano-Al ₂ O ₃ (HFTMS-Al ₂ O ₃ ) was better than that of PFOTMS modified nano-Al ₂ O ₃ (PFOTMS-Al ₂ O ₃ ) at continuous time (24h), that is, the dispersion effect of HFTMS modified nano-Al ₂ O ₃ in oil phase is better.

Therefore, the inventors studied the modification of nano-Al ₂ O ₃ using HFTMS as a modifier in the subsequent examples. At the same time, the inventors used orthogonal experiments (orthogonal experimental design table 2-1) to study and test the effects of reaction temperature, reaction time and modifier dosage on the modified nano-Al ₂ O ₃ , namely, Examples 6 to 14. Among them, the preparation process of Examples 6 to 14 is similar to that of Examples 1 to 5, except that different experimental factors (time, temperature and modifier dosage) are replaced. The static contact angle test results of the modified nano-Al ₂ O ₃ prepared in Examples 6 to 14 are shown in Table 2-2.

Table 2-1 Orthogonal test design table

Table 2-2 Static contact angle test results of modified nano-Al ₂ O ₃ in Examples 6 to 14

From the test results of Examples 6 to 14 in Table 2-2, it can be seen that in the process of modifying nano-Al ₂ O ₃ using HFTMS as a modifier, extending the reaction time, increasing the reaction temperature or increasing the amount of the modifier can improve the hydrophobicity of nano-Al ₂ O ₃ , thereby improving the dispersibility of the modified nano-Al ₂ O ₃ in the oil phase.

At the same time, the above test results also show that when the weight ratio of HFTMS to nano-Al ₂ O ₃ is 0.35:1, the reaction temperature is 70℃, and the reaction time is 4h, the static water contact angle of the prepared modified nano-Al ₂ O ₃ is the largest, which can reach 141.76 ⁰ .

Therefore, the inventors used this as the control condition in the subsequent examples (ie, the process in Example 11 was used as the control standard) to prepare HFTMS-modified nano-Al ₂ O ₃ (HFTMS-Al ₂ O ₃ ) and conducted preparation research on HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst carrier.

（II） Study on HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst support

In order to explore the effect of HFTMS-Al ₂ O ₃ on the preparation process of HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst carrier, the inventors designed the preparation study of HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst carrier under different HFTMS-Al ₂ O ₃ dosages, namely Examples 15 to 18. The micromorphology and static contact angle test results of the HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst carrier prepared in Examples 15 to 18 are shown in Table 3 below.

Preparation process of HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst carrier in Examples 15-18: 400g of distilled water, 0.2g of hydroxymethyl cellulose, 0.3g of sodium dodecylbenzene sulfonate and 3g of polyvinyl alcohol 1788 were placed in a reactor, stirred, heated to 75°C, and kept warm for 2h until the powder was completely dissolved to obtain an aqueous phase. 10g of styrene, 10g of divinylbenzene, 11g of dichloroethane, 15g of toluene, 12g of n-heptane, 0.2g of benzoyl peroxide and different amounts of modified nano-Al ₂ O ₃ were added to a beaker to form an oil phase. The oil phase was slowly added to the water phase, and ultrasonic treatment was first performed for 30 minutes, and then the stirrer speed was adjusted to 200-300 rpm to form uniform small oil droplets; nitrogen was introduced, and the heating rate was strictly controlled to rise to 70°C, and the nitrogen was turned off after isothermal reaction for 1 hour; the temperature was continued to rise to 89°C and isothermal reaction was carried out for 1 hour; when the temperature was raised to 90°C, the isothermal reaction was ended after 5 hours; after filtration, drying and sieving, the HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst carrier was obtained.

The preparation process of Control Example 2 is similar to that of Examples 15 to 18, except that modified nano-Al ₂ O ₃ is not added, and a SDB hydrophobic catalyst carrier is obtained.

Table 3 Microstructure and static contact angle test results of HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst supports in Examples 15 to 18

From the test results of Examples 15 to 18 in Table 3, it can be seen that as the amount of HFTMS-Al ₂ O ₃ added increases, the sphericity of the HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst carrier will change, and may even become an irregular shape. At the same time, the hydrophobic angle of the HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst carrier will increase as the amount of HFTMS-Al ₂ O ₃ added increases, that is, the hydrophobicity is improved. When the amount of HFTMS-Al ₂ O ₃ added reaches 0.15 g (that is, when the weight ratio of styrene, divinylbenzene and modified nano-Al ₂ O ₃ is 10:10:0.15), the HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst carrier exhibits the most outstanding hydrophobic performance.

FIG1 is a schematic diagram of the static contact angle test of the HFTMS- _Al2O3 /SDB _hydrophobic catalyst carrier in Example 17 and the SDB hydrophobic catalyst carrier in Comparative Example 2. FIG1a is a test diagram of the SDB hydrophobic catalyst carrier, and FIG1b is a test diagram of the HFTMS- _Al2O3 /SDB hydrophobic catalyst carrier. It can be clearly seen from _{FIG1 that the HFTMS-Al2O3 /} SDB hydrophobic catalyst carrier is superior to the SDB hydrophobic catalyst carrier, that is, HFTMS _{- Al2O3} gives the SDB hydrophobic catalyst carrier good _hydrophobic properties.

Figure 2 is a scanning electron microscope image of the SDB hydrophobic catalyst support and the HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst support. Figure 2a is a scanning electron microscope image of the SDB hydrophobic catalyst support in Comparative Example 2, and Figure 2b is a scanning electron microscope image of the HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst support in Example 17. It can be seen that the spherical shape of the HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst support is relatively intact and the surface is relatively smooth in macroscopic terms, and the surface of the support is multi-structured and has a larger pore size in microscopic terms.

Taking Examples 16-17 and Comparative Example 2 as examples, the compressive strength test was conducted on the HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst carrier and the SDB hydrophobic catalyst carrier (7 groups were tested and the average value was taken). The test results are shown in Table 4.

Table 4 Compressive strength of HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst carrier in Examples 16-17

From the test results of Examples 16 to 17 in Table 4, it can be seen that the modified HFTMS-Al ₂ O ₃ can significantly improve the compressive strength of the SDB hydrophobic catalyst support.

Taking Example 17 and Comparative Example 2 as examples, the specific surface area, pore volume and pore diameter of the HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst carrier or the SDB hydrophobic catalyst carrier were tested. The test results are shown in Table 5.

Table 5 Specific surface area, pore volume and pore size test results of the HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst support in Example 17

It can be seen from the test results of Example 17 in Table 5 that after adding HFTMS-Al ₂ O ₃ , the specific surface area, pore volume and pore size of the HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst carrier increased.

Taking Example 17 and Comparative Example 2 as examples, infrared detection and thermogravimetric analysis were performed on the HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst support and the SDB hydrophobic catalyst support, and the test results are shown in Figures 3 and 4. The blue curve in Figure 3 is the infrared spectrum of the SDB hydrophobic catalyst support, and the orange-red curve is the infrared spectrum of the HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst support. As can be seen from Figure 3, 3015.16cm ^-1 and 3075.64cm ^-1 correspond to the vibration absorption peaks of the CH bond on the benzene ring, 2934.01cm ^-1 corresponds to the stretching vibration absorption peak of -CH ₂ ; 1640.27cm ^-1 corresponds to the stretching vibration absorption peak of the carbon-carbon double bond; 1498.72cm ^-1 and 1455.01cm ^-1 in the figure correspond to the stretching vibration peaks of the conjugated double bond of the benzene ring skeleton; the absorption peak at 724.06 cm -1 is the carbon chain vibration absorption peak; 1150cm ^-1 corresponds to the stretching vibration absorption peak of -CF _2. From the above analysis, it can be seen that the HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst support was successfully synthesized in Example 17.

Meanwhile, the green curve in FIG4 is the red TG curve of the SDB hydrophobic catalyst carrier, and the red curve is the TG curve of the HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst carrier. As can be seen from FIG4, the thermal decomposition temperature of the SDB hydrophobic catalyst carrier is 382.47°C, while the thermal decomposition temperature of the HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst carrier is 383.56°C, which means that the addition of HFTMS-Al ₂ O ₃ has no significant effect on the thermal properties of the SDB hydrophobic catalyst carrier. The inventors analyzed that the possible reason is that HFTMS will gradually decompose at around 380°C, but since the general catalytic reaction temperature is carried out at 50~80°C, HFTMS will not decompose at this temperature, so it does not affect the use of the HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst carrier.

Taking Example 17 and Comparative Example 2 as examples, element analysis was performed on the HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst carrier, and the analysis results are shown in Figure 5. As can be seen from the figure, the HFTMS-Al ₂ O ₃ /SDB carrier contains F and Si elements, which means that the HFTMS-Al ₂ O ₃ /SDB hydrophobic catalyst carrier was successfully prepared in this example.

Claims (1)

1. The preparation method of the nano aluminum oxide hybridized modified styrene-divinylbenzene copolymer hydrophobic catalyst carrier is characterized by comprising the following steps:

Preparation of modified nano aluminum oxide: 0.35g of heptadecafluorodecyl trimethoxy silane is taken as a modifier, and the volume ratio of the modifier to ethanol is 1:100, respectively mixing the modifier and ethanol to obtain a modifier diluent; adding 1g of nano aluminum oxide into a modifier diluent, controlling the reaction temperature to be 70 ℃, reacting for 4 hours, and sequentially washing with absolute ethyl alcohol and water after the reaction is finished, and drying to obtain modified nano aluminum oxide, wherein the hydrophobic angle of the modified nano aluminum oxide is 141.76 degrees;

Preparation of a nano aluminum oxide hybridization modified styrene-divinylbenzene copolymer hydrophobic catalyst carrier: 400g of distilled water, 0.2g of hydroxymethyl cellulose, 0.3g of sodium dodecyl benzene sulfonate and 1788 g of polyvinyl alcohol are placed in a reactor in parts by mass, stirred, heated to 75 ℃, and kept for 2 hours until powder is completely dissolved, so as to obtain a water phase; 10g of styrene, 10g of divinylbenzene, 11g of dichloroethane, 15g of toluene, 12g of n-heptane, 0.2g of benzoyl peroxide and 0.15g of modified nano-alumina are added into a beaker to form an oil phase; slowly adding the oil phase into the water phase, performing ultrasonic treatment for 30min, and then adjusting the rotating speed of a stirrer to 200-300 rpm to form uniform small oil droplets; introducing nitrogen, strictly controlling the temperature rising rate to 70 ℃, reacting at constant temperature for 1h, and closing the nitrogen; continuously heating to 89 ℃, and reacting for 1h at constant temperature; when the temperature is raised to 90 ℃, the reaction is finished after 5 hours of constant temperature reaction; filtering, drying and screening to obtain a nano aluminum oxide hybridized modified styrene-divinylbenzene copolymer hydrophobic catalyst carrier; the hydrophobic angle of the nano aluminum oxide hybridized modified styrene-divinylbenzene copolymer hydrophobic catalyst carrier is 146.94 degrees, the average compressive strength is 56.18N, the specific surface area is 439.834m ²/g, the pore volume is 0.892cm ³/g, and the pore diameter is 1.692nm.