Search

CN-118634805-B - Catalyst for CO oxidation and preparation method and application thereof

CN118634805BCN 118634805 BCN118634805 BCN 118634805BCN-118634805-B

Abstract

The invention relates to a catalyst for CO oxidation and a preparation method and application thereof, wherein the preparation method comprises the following steps of (1) mixing a titanium source, a silicon source and a solvent, and roasting to obtain a Ti-Si compound; (2) etching the Ti-Si compound to obtain a TiO 2 carrier, and (3) activating the TiO 2 carrier to obtain the catalyst. The Ti-Si compound prepared by combining the cohydrolysis method with the roasting process and the etching means and the activation process can obtain the TiO 2 carrier with (101) high-energy crystal faces and rich defect sites, and the carrier prepared by the method has higher activity and excellent catalytic effect, can effectively realize complete conversion of CO, and greatly reduces the cost input of the catalyst.

Inventors

  • ZHU TINGYU
  • LIU XIAOLONG
  • ZHAO YONGQI
  • ZOU YANG
  • Jin Shuaili

Assignees

  • 中国科学院过程工程研究所

Dates

Publication Date
20260512
Application Date
20240530

Claims (20)

  1. 1. A method of preparing a catalyst, the method comprising the steps of: (1) Mixing a titanium source, a silicon source and a solvent, and roasting to obtain a Ti-Si compound; (2) Etching the Ti-Si compound to obtain a TiO 2 carrier; (3) And mixing a platinum source solution with the TiO 2 carrier, drying and roasting to obtain a TiO 2 carrier loaded with single-atom Pt, and activating the TiO 2 carrier loaded with single-atom Pt at 300-500 ℃ for 0.2-1 h, wherein the gas adopted in the activation comprises any one or a combination of at least two of hydrogen, oxygen and carbon monoxide to obtain the catalyst.
  2. 2. The method for preparing a catalyst according to claim 1, wherein the platinum source in the platinum source solution comprises any one or a combination of at least two of chloroplatinic acid, platinum nitrate, or platinum tetrachloride.
  3. 3. The method for preparing a catalyst according to claim 1, wherein the loading amount of monoatomic Pt is 0 to 100ppm by weight and not including 0ppm by weight.
  4. 4. The method for preparing a catalyst according to claim 1, wherein the baking temperature in the step (3) is 400-600 ℃ in the loading process.
  5. 5. The method for preparing a catalyst according to claim 1, wherein the time of the calcination in the step (3) is 3 to 5 hours during the loading.
  6. 6. The method for preparing a catalyst according to claim 1, wherein the molar ratio of the titanium element in the titanium source to the silicon element in the silicon source in the step (1) is (3-5): 1.
  7. 7. The method of preparing a catalyst according to claim 1, wherein the titanium source of step (1) comprises any one or a combination of at least two of tetrabutyl titanate, titanium tetrachloride or tetraethyl titanate.
  8. 8. The method of preparing a catalyst according to claim 1, wherein the silicon source of step (1) comprises any one or a combination of at least two of tetraethyl silicate, polyethoxy siloxane, or methyltrimethoxysilane.
  9. 9. The method for preparing a catalyst according to claim 1, wherein the step of mixing in step (1) comprises the steps of first mixing the titanium source and the silicon source, and then adding the solvent for second mixing.
  10. 10. The method for preparing a catalyst according to claim 9, wherein the first mixing time is 0.5 to 2 hours.
  11. 11. The method for preparing a catalyst according to claim 9, wherein the second mixing time is 9 to 15 hours.
  12. 12. The method for preparing a catalyst according to claim 1, wherein the mixed material obtained by mixing is further dried before the calcination in the step (1).
  13. 13. The method for preparing a catalyst according to claim 1, wherein the baking temperature in the step (1) is 500-800 ℃.
  14. 14. The method for preparing a catalyst according to claim 1, wherein the roasting time in the step (1) is 2 to 5 hours.
  15. 15. The method of preparing a catalyst according to claim 1, wherein the etchant used in the etching in the step (2) comprises any one or a combination of at least two of sodium hydroxide solution, potassium hydroxide solution and ammonia water.
  16. 16. The method for preparing a catalyst according to claim 15, wherein the concentration of the etchant is 0.5 to 3mol/L.
  17. 17. The method for preparing a catalyst according to claim 1, wherein the etching temperature in the step (2) is 40-60 ℃.
  18. 18. The method for preparing a catalyst according to claim 1, wherein the etching time in the step (2) is 9-15 hours.
  19. 19. The method for preparing a catalyst according to claim 1, wherein the step (2) further comprises the steps of separating, washing and drying the etched product.
  20. 20. The method for preparing a catalyst according to claim 1, characterized in that the method comprises the steps of: (1) 1, firstly mixing a titanium source and a silicon source for 0.5-2 h according to the mole ratio of the titanium element to the silicon element, then adding a solvent for second mixing for 9-15 h, drying, and roasting for 2-5 h at 500-800 ℃ to obtain a Ti-Si compound; (2) Etching the Ti-Si compound at the temperature of 40-60 ℃ by adopting an etchant with the concentration of 0.5-3 mol/L, wherein the etchant comprises any one or a combination of at least two of sodium hydroxide solution, potassium hydroxide solution and ammonia water, the etching time is 9-15 h, and the TiO 2 carrier is obtained after separation, washing and drying; (3) And mixing a platinum source solution with the TiO 2 carrier, drying, roasting at 400-600 ℃ for 3-5 hours to obtain a single-atom Pt-loaded TiO 2 carrier, wherein the single-atom Pt loading amount is 0-100 ppm and does not comprise 0ppm, and then activating the single-atom Pt-loaded TiO 2 carrier at 300-500 ℃ for 0.2-1 hour, wherein the gas adopted in activation comprises any one or a combination of at least two of hydrogen, oxygen and carbon monoxide, so as to obtain the catalyst.

Description

Catalyst for CO oxidation and preparation method and application thereof Technical Field The invention relates to the technical field of catalysts, in particular to a catalyst for CO oxidation, a preparation method and application thereof. Background In the steel production process, the content of atmospheric pollution discharged by the sintering process is the highest in the whole process, and the total discharge amount of NO x、SO2, particulate matters and CO pollutants discharged by the sintering process is more than half of the total discharge amount of pollutants in the whole steel industry. With the implementation of ultralow emission in the steel industry, the emission level of pollutants such as particulate matters, SO 2、NOx, dioxin and the like in the sintering process is reduced by more than 80%. The most effective method for purifying CO in flue gas is catalytic oxidation technology today, and the core of the method is the development of a catalyst. In particular, in the research of noble metal catalysts, there is a great deal of attention because noble metal catalysts have good catalytic activity and sulfur resistance stability. Xiaole Weng et al (DOI: 10.1002/anie.202310191) prepared a Pd/TiO 2 catalyst with unconventional oxygen saturation (Pd content: 1 wt%) under an oxidizing atmosphere, which contained ultra-small Pd metal, carrier particles with special reactivity and stability, and was capable of achieving stable and efficient catalytic oxidation of CO at 120℃under 21vol% O 2, 100ppm SO 2, and 10vol% water. Hongliang Xin et al (DOI: 10.1021/jacs.2c08902) prepared Pt1 single-atom catalysts (Pt 1), single-layer Pt atoms (PtASL) and multi-layer Pt cluster (PtC) catalysts in different local coordination environments by using a defective CeO 2/Al2O3 carrier, wherein all or part of Pt atoms are embedded into a CeO 2 surface lattice, and the total content of surface-supported Pt is 0.25wt%, so that catalytic oxidation of CO under the condition of 270 ℃ is realized. CN113751024B discloses a catalyst for catalytic oxidation of CO and a preparation method thereof, the invention uses mixed noble metal and non-noble metal as active components, has higher stability and activity at 110 ℃ or above, and the content of noble metal in the active components is 0.09-0.12wt%. In all the above studies, the noble metal content of the synthesized catalyst is basically required to be more than 0.1%, and in the case of a cubic catalyst, the noble metal content of 0.1% will increase the cost of more than 20 ten thousand RMB, which seriously increases the running cost of the iron and steel industry. In short, the current research on the catalyst generally has the problem of excessively high noble metal cost investment, thereby seriously impeding the industrialization process of the catalyst. Therefore, the preparation method of the catalyst is provided, so that the catalyst can be obtained, and meanwhile, the cost input of the catalyst can be further reduced, and the problem to be solved is urgently needed at present. Disclosure of Invention In order to solve the technical problems, the invention aims to provide a catalyst for CO oxidation, and a preparation method and application thereof. The Ti-Si compound prepared by combining the cohydrolysis method with the roasting process and the etching means and the activation process can obtain the TiO 2 carrier with (101) high-energy crystal faces and rich defect sites, and the carrier prepared by the method has higher activity and excellent catalytic effect, can effectively realize complete conversion of CO, and greatly reduces the cost input of the catalyst. To achieve the purpose, the invention adopts the following technical scheme: In a first aspect, the present invention provides a method of preparing a catalyst, the method comprising the steps of: (1) Mixing a titanium source, a silicon source and a solvent, and roasting to obtain a Ti-Si compound; (2) Etching the Ti-Si compound to obtain a TiO 2 carrier; (3) And activating the TiO 2 carrier to obtain the catalyst. The method takes a titanium source and a silicon source as raw materials to carry out cohydrolysis reaction in a solvent, then the raw materials are roasted to prepare the Ti-Si compound, and silicon sites in the Ti-Si compound are etched by adopting an etching means, so that a large number of defect sites are formed, the surface of the catalyst has abundant defect structures, and the active oxygen transfer capability of the surface of the catalyst can be improved. The roasting in the invention can promote the growth of TiO 2 towards 101, and the existence of SiO 2 formed by a silicon source inhibits the transformation of TiO 2 from anatase crystal to rutile crystal, so that the anatase type TiO 2 rich in 101 high-energy crystal faces is finally obtained. The Ti-Si compound prepared by combining the cohydrolysis method with the roasting process and the etching means and the activation process are combined