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CN-121988281-A - Molecular sieve with efficient adsorption performance and preparation method and application thereof

CN121988281ACN 121988281 ACN121988281 ACN 121988281ACN-121988281-A

Abstract

The invention provides a molecular sieve with high-efficiency adsorption performance, and a preparation method and application thereof, and belongs to the technical field of molecular sieves. The invention synthesizes a precursor through low-temperature aging, regulates and controls crystal growth through a variable-temperature crystallization process, removes a template agent at normal temperature by ultraviolet-ozone cooperative treatment, retains active hydroxyl groups of a framework, and carries out functional grafting on the surface of a silane coupling agent after complexing modification by organic acid. The specific surface area of the molecular sieve prepared by the invention is 800-950 m 2 /g, and the molecular sieve has a micropore-mesopore through structure, so that the adsorption performance of the molecular sieve is improved.

Inventors

  • ZHANG KUN
  • WANG YUELING
  • WANG JINGZHOU
  • HE SUJIE

Assignees

  • 郑州雪山实业股份有限公司

Dates

Publication Date
20260508
Application Date
20260330

Claims (10)

  1. 1. The preparation method of the molecular sieve with high-efficiency adsorption performance is characterized by comprising the following steps of: (1) Mixing silica sol with NaOH and distilled water to obtain silica sol solution, mixing sodium aluminate with NaOH and distilled water to obtain sodium aluminate solution, slowly dripping the silica sol solution into the sodium aluminate solution under the ice water bath condition, controlling the dripping speed to be 0.5-2mL/min, heating to 40-60 ℃ after dripping, continuously stirring and ageing for 12-24h; (2) Adding mesoporous template agent, stirring for 2-4 hr, adding microporous template agent, and stirring for 1-2 hr to obtain mixed solution; (3) Transferring the mixed solution into a high-pressure reaction kettle, crystallizing by adopting a variable-temperature crystallization process, filtering and washing the reaction product to be neutral, and drying to obtain molecular sieve raw powder; (4) Placing the molecular sieve raw powder obtained in the step (3) into absolute ethyl alcohol to be stirred and refluxed for 2-4 hours, then placing the molecular sieve raw powder into an ultraviolet-ozone treatment box, and treating the molecular sieve raw powder for 2-4 hours under normal temperature and slight negative pressure; (5) After ultraviolet treatment, immersing the molecular sieve in 0.05-0.2mol/L citric acid solution, and oscillating at 50-70 ℃ for 1-2h; (6) Dispersing the molecular sieve in absolute ethyl alcohol, adding a silane coupling agent, wherein the silane dosage is 1-5% of the molecular sieve mass, and carrying out reflux reaction for 4-8h at 60-80 ℃.
  2. 2. The preparation method of the molecular sieve with the high-efficiency adsorption performance according to claim 1, wherein in the silica sol solution in the step (1), the SiO2 content of the silica sol is 35-45%, and the mass ratio of the silica sol to the NaOH to the distilled water is 10-15:10-45:40-45; in the sodium aluminate solution, the mass ratio of the sodium aluminate to the NaOH to the distilled water is 5-6:3-4:40-45; The mass ratio of the silica sol to the sodium aluminate is 10-15:5-6.
  3. 3. The method for preparing a molecular sieve with high-efficiency adsorption performance according to claim 1, wherein the medium Kong Moban agent in the step (2) is at least one of P123, F127 and CTAB, the molecular weight of the mesoporous template agent is 2000-10000, and the molar ratio of the mesoporous template agent to silica sol is 0.05-1:100.
  4. 4. The method for preparing the molecular sieve with the high-efficiency adsorption performance according to claim 1, wherein the microporous template agent in the step (2) is tetrapropylammonium hydroxide, and the molar ratio of the microporous template agent to silica sol is 0.01-1:1.
  5. 5. The method for preparing a molecular sieve with high-efficient adsorption performance according to claim 1, wherein the temperature-variable crystallization process in the step (3) is to crystallize at a low temperature of 80-100 ℃ for 12-24 hours, and then to crystallize at a high temperature of 140-180 ℃ for 24-48 hours.
  6. 6. The method for preparing the molecular sieve with high-efficiency adsorption performance according to claim 1, wherein the pressure of the normal-temperature micro negative pressure in the step (4) is-0.05 to-0.08 MPa, sectional treatment is adopted, the treatment is firstly carried out for 1-1.5h, then the standing is carried out for 0.5-1h, and finally the treatment is carried out for 1-2h.
  7. 7. The method for preparing a molecular sieve having high adsorption performance according to claim 1, wherein the ultraviolet light in the step (4) has a wavelength of 185nm to 254nm.
  8. 8. The method for preparing a molecular sieve with high-efficient adsorption performance according to claim 1, wherein the silane coupling agent in the step (6) is any one of KH-550 and KH-570.
  9. 9. The molecular sieve with high-efficiency adsorption performance is characterized by being prepared by the preparation method of the molecular sieve with high-efficiency adsorption performance according to any one of claims 1-8, wherein the specific surface area of the molecular sieve is 800-950 m 2 /g, the pore volume is 0.5-1.2cm 3 /g, and the molecular sieve has a micropore-mesopore through multistage pore structure.
  10. 10. The use of a molecular sieve having efficient adsorption properties according to claim 9, wherein the molecular sieve is used for adsorbing acid gases such as carbon dioxide, sulfur dioxide, etc., or for removing organic contaminants from a body of water.

Description

Molecular sieve with efficient adsorption performance and preparation method and application thereof Technical Field The invention belongs to the technical field of molecular sieves, and particularly relates to a molecular sieve with high-efficiency adsorption performance, and a preparation method and application thereof. Background The zeolite molecular sieve has wide application as adsorbent in the fields of gas separation, waste water treatment, catalysis, etc. because of its unique regular pore structure, huge specific surface area and adjustable acid sites. The molecular sieve synthesized by the traditional method is usually mainly composed of micropores, and has single pore diameter, which gives the molecular sieve excellent shape selectivity, but also limits the mass transfer and adsorption rate of the molecular sieve to macromolecular substances or viscous liquid. In addition, when molecular sieve powders are used in actual industrial settings, they often need to be formed into coatings or particles, which can easily lead to blockage of the molecular sieve channels and a reduction in the effective active sites, thereby reducing their overall adsorption properties. Therefore, the development of a molecular sieve preparation method which has a multistage pore structure and a high specific surface area and can still maintain high-efficiency adsorption performance after coating has important practical value. Disclosure of Invention Based on the above, the invention provides a preparation method of a molecular sieve with high-efficiency adsorption performance, which comprises the following steps: (1) Mixing silica sol with NaOH and distilled water to obtain silica sol solution, mixing sodium aluminate with NaOH and distilled water to obtain sodium aluminate solution, slowly dripping the silica sol solution into the sodium aluminate solution under the ice water bath condition, controlling the dripping speed to be 0.5-2mL/min, heating to 40-60 ℃ after dripping, continuously stirring and ageing for 12-24h; (2) Adding mesoporous template agent, stirring for 2-4 hr, adding microporous template agent, and stirring for 1-2 hr to obtain mixed solution; (3) Transferring the mixed solution into a high-pressure reaction kettle, crystallizing by adopting a variable-temperature crystallization process, filtering and washing the reaction product to be neutral, and drying to obtain molecular sieve raw powder; (4) Placing the molecular sieve raw powder obtained in the step (3) into absolute ethyl alcohol to be stirred and refluxed for 2-4 hours, then placing the molecular sieve raw powder into an ultraviolet-ozone treatment box, and treating the molecular sieve raw powder for 2-4 hours under normal temperature and slight negative pressure; (5) After ultraviolet treatment, immersing the molecular sieve in 0.05-0.2mol/L citric acid solution, and oscillating at 50-70 ℃ for 1-2h; (6) Dispersing the molecular sieve in absolute ethyl alcohol, adding a silane coupling agent, wherein the silane dosage is 1-5% of the molecular sieve mass, and carrying out reflux reaction for 4-8h at 60-80 ℃. Preferably, in the silica sol solution in the step (1), the SiO 2 content of the silica sol is 35-45%, and the mass ratio of the silica sol to the NaOH to the distilled water is 10-15:10-45:40-45; in the sodium aluminate solution, the mass ratio of the sodium aluminate to the NaOH to the distilled water is 5-6:3-4:40-45; The mass ratio of the silica sol to the sodium aluminate is 10-15:5-6. Preferably, the medium Kong Moban agent in the step (2) is at least one of P123, F127 and CTAB, the molecular weight of the mesoporous template agent is 2000-10000, and the molar ratio of the medium Kong Moban agent to the silica sol is 0.05-1:100. Preferably, the microporous template agent in the step (2) is tetrapropylammonium hydroxide, and the molar ratio of the microporous template agent to the silica sol is 0.01-1:1. Preferably, the temperature-variable crystallization process in the step (3) is to crystallize for 12-24 hours at a low temperature of 80-100 ℃ and then to crystallize for 24-48 hours at a high temperature of 140-180 ℃. Preferably, the pressure of the normal-temperature micro negative pressure in the step (4) is-0.05 to-0.08 MPa, sectional treatment is adopted, firstly, the treatment is carried out for 1-1.5 hours, then the standing is carried out for 0.5-1 hour, and finally, the treatment is carried out for 1-2 hours. Preferably, the ultraviolet light in the step (4) has a wavelength of 185nm-254nm. Preferably, the silane coupling agent in the step (6) is any one of KH-550 and KH-570. The invention further aims to provide the molecular sieve with high-efficiency adsorption performance, which is prepared by the method, wherein the specific surface area of the molecular sieve is 800-950 m 2/g, the pore volume is 0.5-1.2cm 3/g, and the molecular sieve has a micropore-mesopore through multistage pore structure. The third object of the pres