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US-20260124580-A1 - CATALYST FOR THERMALLY STABLE DEGRADATION OF VOCS, PREPARATION METHOD THEREOF AND USE THEREOF

US20260124580A1US 20260124580 A1US20260124580 A1US 20260124580A1US-20260124580-A1

Abstract

The present application discloses a catalyst for thermally stably degradation of VOCs, a preparation method thereof and a use thereof. The catalyst includes: a substrate, and an auxiliary agent and an active component which are on the substrate. The auxiliary agent includes a first auxiliary agent and a second auxiliary agent; the first auxiliary agent includes a cobalt-containing auxiliary agent and/or an iron-containing auxiliary agent; and the second auxiliary agent includes an aluminum-based auxiliary agent. The combination of specific first and second auxiliary agents is introduced into the catalyst of the present application, so that oxygen molecules can be quickly adsorbed and activated during the catalytic combustion process of VOCs with forming a catalytic synergy center with the active component, thereby improving the removal efficiency for VOCs and facilitating the long-term stable operation of the catalyst under harsh conditions such as high-temperature and high-humidity conditions.

Inventors

  • Zhongbiao Wu
  • Yemin ZHAO
  • Shan GAO
  • Haibo Ni
  • Ziwei Zhou
  • Yuejun Wang
  • Zhongfei Zhang

Assignees

  • ZHEJIANG TIANLAN ENVIRONMENTAL PROTECTION TECHNOLOGY CO., LTD.
  • ZHEJIANG UNIVERSITY

Dates

Publication Date
20260507
Application Date
20251031
Priority Date
20241107

Claims (19)

  1. 1 . A catalyst for thermally stable degradation of volatile organic compounds (VOCs), comprising a substrate, and an auxiliary agent and an active component which are on the substrate, wherein the auxiliary agent comprises a first auxiliary agent and a second auxiliary agent; the first auxiliary agent comprises at least one of a cobalt-containing auxiliary agent or an iron-containing auxiliary agent; and the second auxiliary agent comprises an aluminum-based auxiliary agent.
  2. 2 . The catalyst according to claim 1 , wherein a content of an active element of the first auxiliary agent is 0.2% to 8% of a total mass of the catalyst; and the active element comprises at least one of cobalt or iron.
  3. 3 . The catalyst according to claim 1 , wherein a content of the active component is 0.002% to 1.5% of a total mass of the catalyst.
  4. 4 . The catalyst according to claim 1 , wherein the substrate comprises at least one of honeycomb mullite or honeycomb cordierite; the first auxiliary agent comprises at least one of Co 3 O 4 , CoO, Fe 3 O 4 or Fe 2 O 3 ; and the second auxiliary agent comprises at least one of Al 2 O 3 or pseudoboehmite.
  5. 5 . The catalyst according to claim 1 , wherein the active component comprises at least one of platinum, ruthenium or palladium.
  6. 6 . A method for preparing the catalyst according to claim 1 , comprising: performing first stirring and mixing on a first auxiliary agent dispersion liquid and a second auxiliary agent dispersion liquid to obtain a first mixture, and then performing first calcination on the first mixture to obtain a composite auxiliary agent; performing second stirring and mixing on the composite auxiliary agent and an active component dispersion liquid to obtain a second mixture, and then performing second calcination on the second mixture to obtain a catalyst composite powder; performing ball milling on the catalyst composite powder, the second auxiliary agent and a concentrated acid to obtain a gelled mixture; and combining the gelled mixture with the substrate, and then performing third calcination to obtain the catalyst for thermally stable degradation of the VOCs.
  7. 7 . The method according to claim 6 , wherein the first auxiliary agent dispersion liquid is obtained by dispersing the first auxiliary agent in a first solvent; and the second auxiliary agent dispersion liquid is obtained by dispersing the second auxiliary agent in a second solvent.
  8. 8 . The method according to claim 6 , wherein a mass ratio of the first auxiliary agent in the first auxiliary agent dispersion liquid to the second auxiliary agent in the second auxiliary agent dispersion liquid is (0.1-0.4):1.
  9. 9 . The method according to claim 6 , wherein a temperature of the first calcination is 600° C. to 850° C.; and a time of the first calcination is 2 h to 10 h.
  10. 10 . The method according to claim 6 , wherein the active component dispersion liquid is obtained by dispersing an active substance in a third solvent; and the active substance comprises at least one of platinum nitrate, tetraammine platinum nitrate, chloroplatinic acid, tetraammine platinum chloride, ruthenium chloride, ruthenium nitrosyl nitrate, palladium chloride, palladium nitrate or tetraammine palladium nitrate.
  11. 11 . The method according to claim 10 , wherein a mass ratio of the composite auxiliary agent to the active substance in the active component dispersion liquid is 1:(0.01-0.5).
  12. 12 . The method according to claim 6 , wherein a temperature of the second calcination is 400° C. to 600° C.; and a time of the second calcination is 1 h to 5 h.
  13. 13 . The method according to claim 6 , wherein a mass ratio of the concentrated acid to the second auxiliary agent during the ball milling is (0.01-0.08):1; and a mass ratio of the second auxiliary agent to the catalyst composite powder during the ball milling is (0.05-0.5):1.
  14. 14 . The method according to claim 6 , wherein a time of the ball milling is 30 min to 120 min.
  15. 15 . The method according to claim 14 , wherein a mass ratio of grinding balls to materials during the ball milling is (2-20):1.
  16. 16 . The method according to claim 6 , wherein a temperature of the third calcination is 400° C. to 600° C.; and a time of the third calcination is 1 h to 5 h.
  17. 17 . A use of the catalyst according to claim 1 , comprising using the catalyst for catalytic combustion of the volatile organic compounds.
  18. 18 . The use according to claim 17 , wherein the volatile organic compounds comprise at least one of toluene, propylene or xylene.
  19. 19 . The use according to claim 18 , wherein a water vapor content in the volatile organic compounds is at least 5%.

Description

CROSS-REFERENCE TO RELATED APPLICATION The present application claims the priority and benefit of Chinese patent application No. 202411584635.0, filed on Nov. 7, 2024. The entirety of Chinese patent application No. 202411584635.0 is hereby incorporated by reference herein and made a part of this specification. TECHNICAL FIELD The present application relates to the field of purification of VOCs and, in particular, to a catalyst for thermally stable degradation of VOCs, a preparation method thereof and a use thereof. BACKGROUND ART At present, among the various technologies for controlling VOCs emissions, catalytic combustion has become the mainstream purification technique thanks to its advantages such as high purification efficiency and low energy consumption. Palladium and platinum are generally used as active components of catalysts, and such catalysts have an effective service life of about 12-15 months. However, in working conditions with complex waste gas components and high moisture condition such as those in the pharmaceutical industry, chlor-alkali industry, and garbage/solid waste incineration, the lifespan of the catalysts is shortened to 5-7 months. At the present stage, study conducted by different researchers on improving the performance of catalysts and extending the service life of catalysts mainly focuses on the reconstruction and dosage of notable metals. For example, CN111185221A discloses a PdAg alloy-supported Ti-SBA-15 catalyst and a preparation method therefor and use thereof. The catalyst was prepared by the steps of: dissolving surfactant P123 in hydrochloric acid and stirring at a temperature ranging from 30° C. to 150° C. to obtain a solution; adding tetraethyl orthosilicate and a Ti source dropwise to the above solution, stirring at a temperature of 30° C. to 150° C., then aging the obtained suspension A at a temperature of 40° C. to 150° C., and performing suction filtration, washing and drying, and then calcining at a temperature of 500-550° C. to prepare a Ti-SBA-15 support; dissolving a Pd precursor, an Ag precursor and the Ti-SBA-15 support in ultrapure water, stirring at room temperature to obtain suspension B, and then adding NaBH4 solution, stirring the resulting solution, and performing suction filtration, washing and drying. CN101733165A discloses a preparation method and for a low-content notable metal monolithic catalyst and a use of the low-content notable metal monolithic catalyst. The invention adopts an electroless plating method, in which hydrazine or sodium hypophosphite was used as a reducing agent to undergo an a redox reaction with palladium chloride or chloroplatinic acid in a plating solution and in the meanwhile, under the autocatalysis of Pd or Pt, metal Pd and/or Pt were directly deposited on the surface of honeycomb ceramic pores of cordierite, thus obtaining a supported monolithic catalyst with a low content of Pt and/or Pd noble metal. CN113797961A discloses a RuCe/ZSM-5 molecular sieve catalyst, a preparation method therefor and a use thereof. A Na-ZSM-5 molecular sieve with a micro-mesoporous structure was synthesized hydrothermally and then transformed into H-ZSM-5 by means of ion exchange. Using H-ZSM-5 as a support, Ru and Ce precursor solutions were supported thereon by means of a citric acid sol-gel method, and then calcination was performed, thus obtaining the RuCe/ZSM-5 molecular sieve catalyst. The RuCe-ZSM-5 synthesized by hydrothermal crystallization method in this solution has a multi-stage pore structure, can effectively reduce the mass transfer resistance of chlorobenzene on the catalyst, has greatly improved chlorobenzene conversion performance with a chlorobenzene conversion rate of 98.4% at 275° C., and shows good resistance to chlorine poisoning. However, the molecular sieve has poor hydrothermal stability and the microscopically ordered morphology and structure thereof are prone to collapse in high-temperature and high-humidity environments, which hinders the catalysts from operating for a long time in the above-mentioned environments. In addition, with a high degree of order, few surface defects, and weak interaction with notable metals, the molecular sieve support fails to form a strong metal-support interaction and can hardly prevent the clustering or granulation of notable metal ions at high temperatures. In summary, it can be seen that existing catalysts for degrading VOCs still suffer from low catalytic efficiency and short lifetime under high-temperature and high-humidity conditions. SUMMARY In view of the problems existing in the prior art, an object of the present application is to provide a catalyst for thermally stable degradation of VOCs, a preparation method thereof and a use thereof, so as to solve the problem that catalysts for degrading VOCs still have the defects of poor catalytic efficiency and short service life in high-temperature and high-humidity environments. In order to achieve the above object, the present a