High-efficiency composite catalyst for waste gas purification and use method of high-efficiency composite catalyst

Abstract

The invention discloses a high-efficiency composite catalyst for waste gas purification and a use method thereof, belongs to the technical field of catalysts, and aims to solve the technical problems that a zeolite molecular sieve used as a VOCs catalyst in the prior art is high in hydrophilicity, easy to cause a catalyst poisoning phenomenon and low in adsorption efficiency. The method comprises the following steps; the preparation method comprises the following steps: mixing styrene, divinyl benzene, a hydrophobic metal catalyst and a polar monomer, adding a related auxiliary agent to obtain an oil phase, mixing the oil phase and a water phase, and carrying out post-process treatment to obtain the high-efficiency composite catalyst for waste gas purification. A zeolite molecular sieve is used as a carrier, a hydrophobic inorganic adsorption material is prepared through modification of a modified fluorine-containing silane coupling agent, then the hydrophobic inorganic adsorption material is soaked in a mixed transition metal oxide solution, and the hydrophobic metal catalyst is obtained and has the advantage of being high in catalytic efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of catalysts, and in particular to a high-efficiency composite catalyst for exhaust gas purification and a use method thereof. Background Art

[0003] Common VOCs treatment methods include activated carbon adsorption, solution absorption, condensation and membrane separation. The adsorption method refers to the use of adsorbents (such as activated carbon, activated carbon fiber, resin, molecular sieve) to selectively adsorb each component VOCs. Compared with the incineration method, the adsorption method has the advantages of avoiding carbon dioxide greenhouse gas emissions, requiring high temperatures, and the catalyst is not easily deactivated after a period of use. It is suitable for purifying waste gas with lower VOCs content. In the above-mentioned chemical adsorption process, metal catalysts play an important role in increasing the reaction rate, optimizing reaction conditions, and promoting specific chemical reactions.

[0004] Patent application CN115569666A discloses a hydrophobic VOCs adsorption catalyst, which is obtained by mixing a desiliconized modified ZSM-5 molecular sieve with a high silicon-aluminum ratio and a modified Y molecular sieve in proportion. The ZSM-5 molecular sieve is treated with an acid leaching solution to effectively increase its specific surface area, pore capacity and mesopore volume, thereby improving the adsorption capacity and adsorption saturation of VOCs; however, the selective adsorption of the molecular sieve is only physical adsorption using the molecular sieve structure, and the use of a metal catalyst can promote further chemical conversion of small organic molecules in VOCs, thereby improving the adsorption efficiency of the catalyst.

[0005] In view of the technical defects in this aspect, a solution is now proposed. Summary of the invention

[0006] The purpose of the present invention is to provide a high-efficiency composite catalyst for exhaust gas purification and a method of using the same, in order to solve the technical problems in the prior art that zeolite molecular sieves used as catalysts have strong hydrophilicity, are prone to catalyst poisoning, and have low adsorption efficiency of the zeolite molecular sieves themselves.

[0007] The purpose of the present invention can be achieved by the following technical solution: A high-efficiency composite catalyst for exhaust gas purification, comprising the following steps:

[0008] S1, deionized water, polyethylene, carboxymethyl cellulose and sodium alkylbenzene sulfonate are mixed to obtain an aqueous phase;

[0009] S2, styrene, divinylbenzene, a hydrophobic metal catalyst and a polar monomer are mixed to obtain a mixed monomer; a porogen and an initiator are added to the mixed monomer, and the mixture is mixed uniformly to obtain an oil phase;

[0010] S3. Transferring the oil phase to the water phase to obtain a mixed liquid; the mixed liquid is subjected to post-processing to obtain a high-efficiency composite catalyst for exhaust gas purification.

[0011] The invention uses styrene, divinylbenzene and polar monomers as monomer components, adds a certain amount of porogen and initiator, and then transfers to the water phase for reaction to obtain a catalyst carrier. The hydrophobic metal catalyst is used as an inorganic material and is evenly distributed on the surface of the catalyst carrier to obtain a high-efficiency composite catalyst for exhaust gas purification.

[0012] Furthermore, the preparation method of the hydrophobic metal catalyst comprises the following steps:

[0013] A1, uniformly mixing nitrogen-(3-trimethoxysilylpropyl) undecylfluorohexanamide, ethylene oxide and hydroquinone to obtain a mixed monomer;

[0014] A2. The mixed monomers are heated to 70-80° C. in a closed environment, reacted at this temperature for 2-3 hours, and the waste gas is discharged to obtain an organic liquid; the organic liquid is filtered to obtain a modified fluorine-containing silane coupling agent;

[0015] With hydroquinone as a polymerization inhibitor, the imine group in nitrogen-(3-trimethoxysilylpropyl) undecylfluorohexanamide and ethylene oxide undergo a ring-opening reaction to prepare a modified fluorine-containing silane coupling agent.

[0016] The reaction formula of nitrogen-(3-trimethoxysilylpropyl) undecylfluorohexanamide and ethylene oxide is as follows:

[0017]

[0018] A3, zeolite molecular sieve and 1 mol / L H2SO4 solution were mixed, soaked at 60-70°C for 2-3h, filtered, washed with deionized water, and dried in a vacuum oven at 70-80°C to constant weight to obtain an acidified zeolite molecular sieve;

[0019] A4, uniformly mixing the modified fluorine-containing silane coupling agent and the acidified zeolite molecular sieve, reacting at 70-80° C. for 2-3 hours, filtering, and collecting the solid; vacuum drying the solid to constant weight to obtain a hydrophobic inorganic adsorption material;

[0020] The reaction formula for preparing the hydrophobic inorganic adsorption material by reacting the acidified zeolite molecular sieve with the modified fluorine-containing silane coupling agent is as follows:

[0021]

[0022] A5. Mix Mn(NO3)2, Cu(NO3)2, Ce(NO3)3, citric acid and DMF to obtain a mixed metal solution; heat the mixed metal solution to 50-60°C with mechanical stirring until the mixed metal solution is in a sol state, then stop heating and cool naturally to room temperature to obtain a mixed transition metal oxide solution;

[0023] Transition metal oxides have certain catalytic activity and have the advantages of good thermal stability and strong resistance to poisoning.

[0024] A6. Immerse the hydrophobic inorganic adsorption material into the mixed transition metal oxide solution and adsorb for 5-10 minutes to obtain a modified solid; dry the modified solid at 70-80° C. to constant weight to obtain a hydrophobic metal catalyst.

[0025] The hydrophobic inorganic adsorption material adsorbs the mixed transition metal oxides through a solution impregnation method, thereby preparing a modified solid loaded with multiple transition metal oxides.

[0026] Furthermore, in step A1, the dosage ratio of nitrogen-(3-trimethoxysilylpropyl)undecylfluorohexanamide, ethylene oxide and hydroquinone is 50-100g:20-40g; 3-5g; in step A3, the dosage ratio of zeolite molecular sieve and H2SO4 solution is 10-20g; 50mL; in step A4, the dosage ratio of modified fluorine-containing silane coupling agent and acidified zeolite molecular sieve is 50g; 10-20g.

[0027] Furthermore, in step A5, the usage ratio of Mn(NO3)2, Cu(NO3)2, Ce(NO3)3, citric acid and DMF is 2-3g; 2-3g; 2-3g; 5-10g; 100mL; in step A6, the usage ratio of hydrophobic inorganic adsorbent material and mixed transition metal oxide solution is 10-20g; 100mL.

[0028] Furthermore, in step S1, the dosage ratio of deionized water, polyvinyl alcohol, carboxymethyl cellulose and sodium alkylbenzene sulfonate is 200 mL: 2-5 g: 0.1-0.5 g: 0.2-0.6 g; the mixing speed is 100-200 r / min, the mixing temperature is 70-80° C., and the mixing time is 1-2 h.

[0029] Furthermore, in step S2, the usage ratio of styrene, divinylbenzene, hydrophobic metal catalyst and polar monomer is 10-20g:10-15g:10-20g:10-20g; the porogen is a mixture of toluene and n-heptane, and the initiator is dibenzoyl peroxide; the usage ratio of toluene, n-heptane and dibenzoyl peroxide is 15-20g:12-15g:0.2g.

[0030] Further, in step S2, the polar monomer is prepared by the following steps:

[0031] 8-16 g of methacrylic acid, 200 mL of deionized water and 10-20 g of diethanolamine are mixed and stirred to obtain a mixed solution; the mixed solution is heated to 70-80° C. and reacted for 2-3 hours to obtain a product; the product is distilled under reduced pressure to remove deionized water to obtain a polar monomer.

[0032] Methacrylic acid and diethanolamine react to prepare a polar monomer as follows:

[0033]

[0034] Furthermore, in step S3, the post-process treatment is specifically as follows: the mixed solution is set at a step temperature of 45-50°C, and the temperature is maintained for 20 minutes at each increase of 5°C, until the temperature of the three-necked flask is raised to 70-75°C, and it is kept warm at this temperature for 1 hour; the mixed solution is then heated to 90°C, and the particles of the mixed solution begin to solidify, and it is kept warm at this temperature for 5 hours to stop the above reaction; the mixed solution is naturally cooled to room temperature, filtered, washed, and then vacuum dried at 60°C to constant weight to obtain a composite hydrophobic macroporous resin for exhaust gas purification.

[0035] The present invention also provides a method for using a high-efficiency composite catalyst for exhaust gas purification, comprising the following steps:

[0036] The prepared high-efficiency composite catalyst for exhaust gas purification is heat-treated at 100-120° C. for 24 hours to obtain an activated catalyst;

[0037] The activated catalyst is loaded into the adsorption column in the dynamic adsorption experimental device to adsorb the industrial waste gas.

[0038] The prepared high-efficiency composite catalyst is heat-treated at a relatively high temperature before use to convert its metal active center into an active state, thereby further stimulating the catalytic performance of the catalyst.

[0039] Furthermore, the height-to-diameter ratio of the adsorption column is 1:8, the catalyst loading volume is 60-70% of the volume of the adsorption column; the flow rate of the industrial waste gas flowing into the adsorption column is 10-20m 3 / h, the residence time of industrial waste gas in the adsorption column is 10-60min.

[0040] The present invention has the following beneficial effects:

[0041] 1. The present invention uses styrene, divinylbenzene and polar monomers as monomers, and the macroporous resin obtained by addition polymerization as a carrier. In the above-mentioned polymerization process, a certain amount of hydrophobic metal catalyst is dispersed as an active center body; the hydrophobic metal catalyst includes two parts: a hydrophobic inorganic adsorption material and a transition metal oxide, and the hydrophobic inorganic adsorption material is a carrier of the transition metal oxide; wherein, the specific surface area size and the number of active sites of the hydrophobic inorganic adsorption material are important factors affecting the catalytic activity of the prepared hydrophobic metal catalyst. The hydrophobic inorganic adsorption material prepared by the present invention is specifically obtained by reacting an acidified zeolite molecular sieve and a modified fluorine-containing silicon silane coupling agent; the raw materials of the zeolite molecular sieve are cheap and easy to obtain, which reduces the cost of preparing the catalyst. However, the Si-OH-Al structure of the zeolite molecular sieve connecting chain can form hydrogen bonds with water molecules, thus showing extremely strong hydrophilic properties, and the presence of water vapor will affect the adsorption performance of the zeolite molecular sieve for VOCs; the introduction of a large amount of fluorine elements into the modified silane coupling agent can improve the hydrophobic properties of the zeolite molecular sieve itself, and prevent the catalyst micropores from being blocked by liquid and capillary condensed water at low temperatures, that is, catalyst poisoning. On the other hand, the hydroxyl groups on the acidified zeolite molecular sieve and the modified fluorinated silane coupling agent are prone to esterification reactions, thereby improving the integrity of the hydrophobic inorganic adsorption material. Using the modified fluorinated silane coupling agent as a connecting intermediary, the mixed transition metal oxides are evenly distributed on the surface of the acidified zeolite molecular sieve, thereby obtaining a hydrophobic metal catalyst with both adsorption efficiency and catalytic efficiency.

[0042] 2. In the preparation of macroporous resin, the present invention uses a mixture of n-heptane and n-butanol as a porogen, and the formed resin copolymer has the characteristics of large pore volume, large specific surface area, and large average pore size; on the one hand, it can improve its own adsorption efficiency for VOCs waste gas; on the other hand, it can have enough space volume to carry hydrophobic metal catalysts. However, the resin prepared by cross-linking styrene and divinylbenzene is a non-polar adsorption resin, and the adsorption efficiency of halogenated hydrocarbons and aromatic hydrocarbons in VOCs is low; by reacting methacrylic acid and diethanolamine, a polyimino and polyhydroxy polar monomer is prepared, which is suitable for improving the adsorption of polar substances in VOCs. DETAILED DESCRIPTION

[0043] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] Example 1

[0045] This embodiment provides a method for preparing a hydrophobic metal catalyst for an efficient composite catalyst for exhaust gas purification, comprising the following steps:

[0046] A1. Add 50 g of nitrogen-(3-trimethoxysilylpropyl) undecylfluorohexanamide into a 100 mL three-necked flask, transfer the three-necked flask to an ice bath, set the temperature of the ice bath to -30°C, then add 20 g of ethylene oxide and 3 g of inhibitor hydroquinone into the three-necked flask, stir evenly at 100 r / min, and then seal the three-necked flask to obtain a mixed monomer.

[0047] A2. Heat the three-necked flask to 70°C, mix and stir at 200 r / min, react for 2 hours, discharge the waste gas, and obtain an organic liquid; filter the solid impurities from the organic liquid to obtain a modified fluorine-containing silane coupling agent.

[0048] A3. Mix 10 g of zeolite molecular sieve and 50 mL of 1 mol / L H2SO4 solution, soak at 60°C for 2 h, filter, wash with deionized water, and dry in a vacuum oven at 70-80°C to constant weight to obtain an acidified zeolite molecular sieve.

[0049] A4. Add 50 g of modified fluorinated silane coupling agent into a 100 mL three-necked flask, then add 10 g of acidified zeolite molecular sieve, transfer the three-necked flask to a water bath, stir mechanically at 100 r / min, react at 70 ° C for 2 h, filter and collect the solid; vacuum dry the solid to constant weight to obtain a hydrophobic inorganic adsorption material.

[0050] A5. Add Mn(NO3)2, Cu(NO3)2, Ce(NO3)3, citric acid and DMF into a beaker, mix evenly at 100 r / min to obtain a mixed metal solution; then transfer the beaker to a water bath, adjust the temperature of the water bath to 50°C, and stir mechanically at 100 r / min until the mixed metal solution is in a sol-like state. Then stop heating and cool naturally to room temperature to obtain a mixed transition metal oxide solution.

[0051] A6. Immerse 10 g of the hydrophobic inorganic adsorbent material into 100 mL of a mixed transition metal oxide solution, and adsorb for 5 min to obtain a modified solid; dry the modified solid in a drying oven to a constant weight to obtain a hydrophobic metal catalyst.

[0052] Example 2

[0053] This embodiment provides a method for preparing a hydrophobic metal catalyst for an efficient composite catalyst for exhaust gas purification, comprising the following steps:

[0054] A1. Add 80 g of nitrogen-(3-trimethoxysilylpropyl) undecylfluorohexanamide into a 100 mL three-necked flask, transfer the three-necked flask to an ice bath, set the temperature of the ice bath to -30°C, then add 30 g of ethylene oxide and 4 g of inhibitor hydroquinone into the three-necked flask, stir evenly at 100 r / min, and then seal the three-necked flask to obtain a mixed monomer.

[0055] A2. Heat the three-necked flask to 75°C, mix and stir at 240 r / min, react for 2.3 hours, discharge the waste gas, and obtain an organic liquid; filter the solid impurities from the organic liquid to obtain a modified fluorine-containing silane coupling agent.

[0056] A3. Mix 16 g of zeolite molecular sieve and 50 mL of 1 mol / L H2SO4 solution, soak at 65°C for 2.5 h, filter, wash with deionized water, and dry in a vacuum oven at 76°C to constant weight to obtain an acidified zeolite molecular sieve.

[0057] A4. Add 50 g of modified fluorinated silane coupling agent into a 100 mL three-necked flask, then add 15 g of acidified zeolite molecular sieve, transfer the three-necked flask to a water bath, and react at 73 ° C for 2.6 h accompanied by mechanical stirring at 150 r / min, then filter and collect the solid; vacuum dry the solid to constant weight to obtain a hydrophobic inorganic adsorption material.

[0058] A5. Add Mn(NO3)2, Cu(NO3)2, Ce(NO3)3, citric acid and DMF into a beaker, mix evenly at 120r / min to obtain a mixed metal solution; then transfer the beaker to a water bath, adjust the temperature of the water bath to 55°C, and stir mechanically at 100r / min until the mixed metal solution is in a sol-like state. Then stop heating and cool naturally to room temperature to obtain a mixed transition metal oxide solution.

[0059] A6. Immerse 16 g of the hydrophobic inorganic adsorption material into 100 mL of the mixed transition metal oxide solution, and adsorb for 6 min to obtain a modified solid; dry the modified solid in a drying oven to constant weight to obtain a hydrophobic metal catalyst.

[0060] Example 3

[0061] This embodiment provides a method for preparing a hydrophobic metal catalyst for an efficient composite catalyst for exhaust gas purification, comprising the following steps:

[0062] A1. Add 100 g of nitrogen-(3-trimethoxysilylpropyl) undecylfluorohexanamide into a 100 mL three-necked flask, transfer the three-necked flask to an ice bath, set the temperature of the ice bath to -30°C, then add 40 g of ethylene oxide and 5 g of inhibitor hydroquinone into the three-necked flask, stir evenly at 100 r / min, and then seal the three-necked flask to obtain a mixed monomer.

[0063] A2. Heat the three-necked flask to 80°C, mix and stir at 300 r / min, react for 3 hours, discharge the waste gas, and obtain an organic liquid; filter the solid impurities from the organic liquid to obtain a modified fluorine-containing silane coupling agent.

[0064] A3. Mix 20 g of zeolite molecular sieve and 50 mL of 1 mol / L H2SO4 solution, soak at 70°C for 3 h, filter, wash with deionized water, and dry in a vacuum oven at 80°C to constant weight to obtain an acidified zeolite molecular sieve.

[0065] A4. Add 50 g of modified fluorinated silane coupling agent into a 100 mL three-necked flask, then add 20 g of acidified zeolite molecular sieve, transfer the three-necked flask to a water bath, stir mechanically at 200 r / min, react at 80° C. for 3 h, then filter and collect the solid; vacuum dry the solid to constant weight to obtain a hydrophobic inorganic adsorption material.

[0066] A5. Add Mn(NO3)2, Cu(NO3)2, Ce(NO3)3, citric acid and DMF into a beaker, mix evenly at 200r / min to obtain a mixed metal solution; then transfer the beaker to a water bath, adjust the temperature of the water bath to 60°C, and stir mechanically at 100r / min until the mixed metal solution is in a sol-like state. Then stop heating and cool naturally to room temperature to obtain a mixed transition metal oxide solution.

[0067] A6. Immerse 20 g of the hydrophobic inorganic adsorbent material into 100 mL of a mixed transition metal oxide solution, and adsorb for 10 min to obtain a modified solid; dry the modified solid in a drying oven to a constant weight to obtain a hydrophobic metal catalyst.

[0068] Example 4

[0069] This embodiment provides a method for preparing a high-efficiency composite catalyst for exhaust gas purification, comprising the following steps:

[0070] S1. Measure 200 mL of deionized water and add it into a 500 mL three-necked flask. Weigh 2 g of polyvinyl alcohol, 0.1 g of carboxymethyl cellulose and 0.2 g of sodium alkylbenzene sulfonate and add them into the three-necked flask. Stir mechanically at 100 r / min and mix and react at 70° C. for 1 h to obtain an aqueous phase.

[0071] S2, 100mL of deionized water and 8g of methacrylic acid were added to a 250mL beaker, and then 10g of diethanolamine was added, and the mixture was stirred for 5min with a mechanical stirring speed of 100r / min to obtain a mixed solution. The beaker was then heated to 70°C and reacted for 2h to obtain a product; the product was distilled under reduced pressure to remove the solvent deionized water, and an organic liquid polar monomer was obtained.

[0072] S3. Weigh 10 g of styrene, 10 g of divinylbenzene, 10 g of the hydrophobic metal catalyst prepared in Example 1 and 10 g of the polar monomer, and mix them to obtain a modified white ball; then add 15 g of toluene, 12 g of n-heptane and 0.2 g of dibenzoyl peroxide to the modified white ball, add them into a 100 mL beaker, and stir until the monomers are completely dispersed to obtain an oil phase.

[0073] S4, nitrogen is introduced into the three-necked flask until the three-necked flask is placed in a nitrogen atmosphere; then the three-necked flask is transferred to a water bath, the temperature of the water bath is adjusted to 45°C, and then all the oil phase is transferred to the three-necked flask; the water bath is set to a step temperature, and the temperature is maintained for 20 minutes at each increase of 5°C until the three-necked flask is heated to 70°C. Then the three-necked flask is kept warm at this temperature for 1 hour; then the three-necked flask is heated stepwise, and the temperature is maintained for 30 minutes at each increase of 5°C until particles appear in the three-necked flask, and then kept warm at this temperature for 1 hour; then the three-necked flask is heated to 90°C, and the particles begin to solidify, and the temperature is maintained at this temperature for 5 hours to stop the above reaction; the three-necked flask is naturally cooled to room temperature, and after cooling, it is filtered and washed several times, and then vacuum dried at 60°C to constant weight to obtain a high-efficiency composite catalyst for exhaust gas purification.

[0074] Example 5

[0075] This embodiment provides a method for preparing a high-efficiency composite catalyst for exhaust gas purification, comprising the following steps:

[0076] S1. 200 mL of deionized water was measured and added into a 500 mL three-necked flask. 3 g of polyvinyl alcohol, 0.2 g of carboxymethyl cellulose and 0.4 g of sodium alkylbenzene sulfonate were weighed and added into the three-necked flask. The mixture was stirred at 150 r / min and mixed at 73° C. for 1.3 h to obtain an aqueous phase.

[0077] S2, 100mL of deionized water and 12g of methacrylic acid were added to a 250mL beaker, and then 15g of diethanolamine was added, and the mixture was stirred at 160r / min for 8min to obtain a mixed solution. The beaker was then heated to 75°C and reacted for 2.5h to obtain a product; the product was distilled under reduced pressure to remove the solvent deionized water, and an organic liquid polar monomer was obtained.

[0078] S3. Weigh 17 g of styrene, 12 g of divinylbenzene, 15 g of the hydrophobic metal catalyst prepared in Example 2 and 15 g of the polar monomer, and mix them to obtain a modified white ball; then add 16 g of toluene, 13 g of n-heptane and 0.2 g of dibenzoyl peroxide to the modified white ball, add them into a 100 mL beaker, and stir until the monomers are completely dispersed to obtain an oil phase.

[0079] S4, nitrogen is introduced into the three-necked flask until the three-necked flask is placed in a nitrogen atmosphere; then the three-necked flask is transferred to a water bath, the temperature of the water bath is adjusted to 46°C, and then the oil phase is transferred to the three-necked flask; the water bath is set to a step temperature, and the temperature is maintained for 20 minutes at each increase of 5°C until the three-necked flask is heated to 72°C. Then the three-necked flask is kept warm at this temperature for 1 hour; then the three-necked flask is heated stepwise, and the temperature is maintained for 30 minutes at each increase of 5°C until particles appear in the three-necked flask, and then kept warm at this temperature for 1 hour; then the three-necked flask is heated to 90°C, and the particles begin to solidify, and the temperature is maintained at this temperature for 5 hours to stop the above reaction; the three-necked flask is naturally cooled to room temperature, and after cooling, it is filtered and washed several times, and then vacuum dried at 60°C to constant weight to obtain a high-efficiency composite catalyst for exhaust gas purification.

[0080] Example 6

[0081] This embodiment provides a method for preparing a high-efficiency composite catalyst for exhaust gas purification, comprising the following steps:

[0082] S1. 200 mL of deionized water was measured and added into a 500 mL three-necked flask. 5 g of polyvinyl alcohol, 0.5 g of carboxymethyl cellulose and 0.6 g of sodium alkylbenzene sulfonate were weighed and added into the three-necked flask. The mixture was stirred at 200 r / min and mixed at 80° C. for 2 h to obtain an aqueous phase.

[0083] S2, 100mL of deionized water and 16g of methacrylic acid were added to a 250mL beaker, and then 20g of diethanolamine was added, and the mixture was stirred for 10min with a mechanical stirring of 200r / min to obtain a mixed solution. The beaker was then heated to 80°C and reacted for 3h to obtain a product; the product was distilled under reduced pressure to remove the solvent deionized water, and an organic liquid polar monomer was obtained.

[0084] S3. Weigh 20 g of styrene, 15 g of divinylbenzene, 20 g of the hydrophobic metal catalyst prepared in Example 3 and 10-20 g of the polar monomer, and mix them to obtain a modified white ball; then add 20 g of toluene, 15 g of n-heptane and 0.2 g of dibenzoyl peroxide to the modified white ball, add them into a 100 mL beaker, and stir until the monomers are completely dispersed to obtain an oil phase.

[0085] S4, nitrogen is introduced into the three-necked flask until the three-necked flask is placed in a nitrogen atmosphere; then the three-necked flask is transferred to a water bath, the temperature of the water bath is adjusted to 50°C, and then the oil phase is transferred to the three-necked flask; the water bath is set to a step temperature, and the temperature is maintained for 20 minutes at each increase of 5°C until the three-necked flask is heated to 75°C. Then the three-necked flask is kept warm at this temperature for 1 hour; then the three-necked flask is heated stepwise, and the temperature is maintained for 30 minutes at each increase of 5°C until particles appear in the three-necked flask, and then kept warm at this temperature for 1 hour; then the three-necked flask is heated to 90°C, and the particles begin to solidify, and the temperature is maintained at this temperature for 5 hours to stop the above reaction; the three-necked flask is naturally cooled to room temperature, and after cooling, it is filtered and washed several times, and then vacuum dried at 60°C to constant weight to obtain a high-efficiency composite catalyst for exhaust gas purification.

[0086] Example 7

[0087] This embodiment provides a method for using a high-efficiency composite catalyst for exhaust gas purification, comprising the following steps:

[0088] B1. The high-efficiency composite catalyst for exhaust gas purification prepared in Example 4 was heat treated at 100° C. for 24 hours to obtain an activated catalyst. The activated catalyst was loaded into an adsorption column in a dynamic adsorption experimental device, which consisted of an adsorption column, a flow system for supplying gas, and an analysis system for monitoring the composition of the outflowing gas; wherein the height-to-diameter ratio of the adsorption column was 1:8, and the loading volume of the catalyst was 60% of the volume of the adsorption column.

[0089] B2, industrial waste gas 10m 3 / h flows into the adsorption column until it fills the entire adsorption column; the industrial waste gas stays in the adsorption column for 10 minutes, and then the composition of the outflowing gas is detected by the analysis system to calculate the adsorption efficiency of the corresponding VOCs gas.

[0090] Example 8

[0091] This embodiment provides a method for using a high-efficiency composite catalyst for exhaust gas purification, comprising the following steps:

[0092] B1. The high-efficiency composite catalyst for exhaust gas purification prepared in Example 5 was heat treated at 110° C. for 24 hours to obtain an activated catalyst. The activated catalyst was loaded into an adsorption column in a dynamic adsorption experimental device, which consisted of an adsorption column, a flow system for supplying gas, and an analysis system for monitoring the composition of the outflowing gas; wherein the height-to-diameter ratio of the adsorption column was 1:8, and the loading volume of the catalyst was 65% of the volume of the adsorption column.

[0093] B2, industrial waste gas 10m 3 / h flows into the adsorption column until it fills the entire adsorption column; the industrial waste gas stays in the adsorption column for 30 minutes, and then the composition of the outflowing gas is detected by the analysis system to calculate the adsorption efficiency of the corresponding VOCs gas.

[0094] Example 9

[0095] This embodiment provides a method for using a high-efficiency composite catalyst for exhaust gas purification, comprising the following steps:

[0096] B1. The high-efficiency composite catalyst for exhaust gas purification prepared in Example 6 was heat-treated at 120° C. for 24 hours to obtain an activated catalyst. The activated catalyst was loaded into an adsorption column in a dynamic adsorption experimental device, which consisted of an adsorption column, a flow system for supplying gas, and an analysis system for monitoring the composition of the outflowing gas; wherein the height-to-diameter ratio of the adsorption column was 1:8, and the loading volume of the catalyst was 70% of the volume of the adsorption column.

[0097] B2, industrial waste gas 10m 3 / h flows into the adsorption column until it fills the entire adsorption column; the industrial waste gas stays in the adsorption column for 60 minutes, and then the composition of the outflowing gas is detected by the analysis system to calculate the adsorption efficiency of the corresponding VOCs gas.

[0098] Comparative Example 1

[0099] The difference between this comparative example and Example 6 is that no hydrophobic metal catalyst is added when preparing the high-efficiency composite catalyst for exhaust gas purification.

[0100] Comparative Example 2

[0101] The difference between this comparative example and Example 6 is that when preparing the high-efficiency composite catalyst for exhaust gas purification, the silane coupling agent KH550 is used instead of the modified fluorine-containing silane coupling agent to modify the acidified zeolite molecular sieve.

[0102] Comparative Example 3

[0103] The difference between this comparative example and Example 6 is that when preparing the high-efficiency composite catalyst for exhaust gas purification, no polar monomer is added to the oil phase.

[0104] Performance testing:

[0105] The conversion rates of VOCs gas in industrial waste gas after flowing out at 10min, 30min and 60min in the dynamic adsorption experimental device after loading the catalyst in Examples 7-9 and Comparative Examples 1-3 were recorded in sequence. The specific test results are shown in the following table:

[0106] Table 1 - Sample performance test data table

[0107]

[0108] Data Analysis:

[0109] The high-efficiency composite catalyst for waste gas purification prepared in Examples 4-6 of the present invention has a high adsorption efficiency for VOCs gas, which is manifested in that in Examples 7-9, when the above-mentioned catalyst is used to adsorb industrial waste gas, after 60 minutes of adsorption, the content of VOCs gas in the outflowing gas is low and the conversion rate values ​​are relatively high.

[0110] In Comparative Example 1, when preparing the high-efficiency composite catalyst for exhaust gas purification, no hydrophobic metal catalyst was added, and the lack of chemically active centers reduced the catalytic activity of the prepared high-efficiency composite catalyst for exhaust gas purification, which was manifested as a decrease in the conversion rate value.

[0111] In Comparative Example 2, when preparing a high-efficiency composite catalyst for exhaust gas purification, the fluorine element was not introduced into the coupling agent when the acidified zeolite molecular sieve was modified, thereby reducing the hydrophobic properties of the hydrophobic inorganic adsorption material, which is not conducive to the continuous activity of the catalyst, and is manifested as a decrease in the conversion rate value.

[0112] In Comparative Example 3, when preparing the high-efficiency composite catalyst for exhaust gas purification, no polar monomer was added to the copolymer resin, which reduced the content of polar functional groups and thus reduced the adsorption efficiency.

[0113] The above contents are merely examples and explanations of the structure of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the structure of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

[0114] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0115] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A high-efficiency composite catalyst for exhaust gas purification, characterized in that: The high-efficiency composite catalyst is prepared by the following steps: S1, deionized water, polyethylene, carboxymethyl cellulose and sodium alkylbenzene sulfonate are mixed, stirred and reacted to obtain an aqueous phase; S2, styrene, divinylbenzene, a hydrophobic metal catalyst and a polar monomer are mixed to obtain a mixed monomer; a porogen and an initiator are added to the mixed monomer, and the mixture is mixed uniformly to obtain an oil phase; S3. The oil phase is transferred to the water phase to obtain a mixed liquid; the mixed liquid is subjected to post-processing to obtain a high-efficiency composite catalyst for exhaust gas purification.

2. The high-efficiency composite catalyst for exhaust gas purification according to claim 1, characterized in that: In step S2, the method for preparing the hydrophobic metal catalyst comprises the following steps: A1, uniformly mixing nitrogen-(3-trimethoxysilylpropyl) undecylfluorohexanamide, ethylene oxide and hydroquinone to obtain a mixed monomer; A2. The mixed monomers are heated to 70-80° C. in a closed environment, reacted at this temperature for 2-3 hours, and the waste gas is discharged to obtain an organic liquid; the organic liquid is filtered to obtain a modified fluorine-containing silane coupling agent; A3, zeolite molecular sieve and 1 mol / L H2SO4 solution were mixed, soaked at 60-70°C for 2-3h, filtered, washed with deionized water, and dried in a vacuum oven at 70-80°C to constant weight to obtain an acidified zeolite molecular sieve; A4, uniformly mixing the modified fluorine-containing silane coupling agent and the acidified zeolite molecular sieve, reacting at 70-80° C. for 2-3 hours, filtering, and collecting the solid; vacuum drying the solid to constant weight to obtain a hydrophobic inorganic adsorption material; A5. Mix Mn(NO3)2, Cu(NO3)2, Ce(NO3)3, citric acid and DMF to obtain a mixed metal solution; heat the mixed metal solution to 50-60°C with mechanical stirring until the mixed metal solution is in a sol state, then stop heating and cool naturally to room temperature to obtain a mixed transition metal oxide solution; A6. Immerse the hydrophobic inorganic adsorption material into the mixed transition metal oxide solution and adsorb for 5-10 minutes to obtain a modified solid; dry the modified solid at 70-80° C. to a constant weight to obtain a hydrophobic metal catalyst.

3. The high-efficiency composite catalyst for exhaust gas purification according to claim 2, characterized in that: In step A1, the usage ratio of nitrogen-(3-trimethoxysilylpropyl)undecylfluorohexanamide, ethylene oxide and hydroquinone is 50-100g:20-40g; 3-5g; in step A3, the usage ratio of zeolite molecular sieve and H2SO4 solution is 10-20g; 50mL; in step A4, the usage ratio of modified fluorine-containing silane coupling agent and acidified zeolite molecular sieve is 50g; 10-20g.

4. The high-efficiency composite catalyst for exhaust gas purification according to claim 2, characterized in that: In step A5, the usage ratio of Mn(NO3)2, Cu(NO3)2, Ce(NO3)3, citric acid and DMF is 2-3g; 2-3g; 2-3g; 5-10g; 100mL; in step A6, the usage ratio of hydrophobic inorganic adsorbent material and mixed transition metal oxide solution is 10-20g; 100mL.

5. The high-efficiency composite catalyst for exhaust gas purification according to claim 1, characterized in that: In step S1, the dosage ratio of deionized water, polyvinyl alcohol, carboxymethyl cellulose and sodium alkylbenzene sulfonate is 200 mL: 2-5 g: 0.1-0.5 g: 0.2-0.6 g; the mixing speed is 100-200 r / min, the mixing temperature is 70-80° C., and the mixing time is 1-2 h.

6. The high-efficiency composite catalyst for exhaust gas purification according to claim 1, characterized in that: In step S2, the usage ratio of styrene, divinylbenzene, hydrophobic metal catalyst and polar monomer is 10-20g:10-15g:10-20g:10-20g; the porogen is a mixture of toluene and n-heptane, and the initiator is dibenzoyl peroxide; the usage ratio of toluene, n-heptane and dibenzoyl peroxide is 15-20g:12-15g:0.2g.

7. The high-efficiency composite catalyst for exhaust gas purification according to claim 1, characterized in that: In step S2, the polar monomer is prepared by the following steps: 8-16 g of methacrylic acid, 200 mL of deionized water and 10-20 g of diethanolamine are mixed and stirred to obtain a mixed solution; the mixed solution is heated to 70-80° C. and reacted for 2-3 hours to obtain a product; the product is distilled under reduced pressure to remove deionized water to obtain a polar monomer.

8. The high-efficiency composite catalyst for exhaust gas purification according to claim 1, characterized in that: In step S3, the post-process treatment is specifically as follows: the mixed solution is set at a step temperature of 45-50°C, and the temperature is maintained for 20 minutes at each increase of 5°C, until the temperature of the three-necked flask is raised to 70-75°C, and it is kept warm at this temperature for 1 hour; then the mixed solution is heated to 90°C, and the particles of the mixed solution begin to solidify, and it is kept warm at this temperature for 5 hours to stop the above reaction; the mixed solution is naturally cooled to room temperature, filtered, washed, and then vacuum dried at 60°C to constant weight to obtain a composite hydrophobic macroporous resin for exhaust gas purification.

9. A method for using a high-efficiency composite catalyst for exhaust gas purification according to any one of claims 1 to 8, characterized in that: The following steps are involved: The prepared high-efficiency composite catalyst for exhaust gas purification is heat-treated at 100-120° C. for 24 hours to obtain an activated catalyst; The activated catalyst is loaded into the adsorption column in the dynamic adsorption experimental device to adsorb the industrial waste gas.

10. A method for using a high-efficiency composite catalyst for exhaust gas purification as claimed in claim 9, characterized in that: The height-to-diameter ratio of the adsorption column is 1:8, the catalyst loading volume is 60-70% of the adsorption column volume; the flow rate of industrial waste gas flowing into the adsorption column is 10-20m 3 / h, the residence time of industrial waste gas in the adsorption column is 10-60min.

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