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CN-117443376-B - Catalyst for removing volatile organic compounds, preparation method and application thereof

CN117443376BCN 117443376 BCN117443376 BCN 117443376BCN-117443376-B

Abstract

The invention relates to the field of catalyst preparation, and discloses a catalyst for removing volatile organic compounds, a preparation method and application thereof, wherein the catalyst comprises a carrier and an active component loaded on the carrier; wherein the active component comprises noble metal and matrix metal oxide, wherein the noble metal is Pt metal and/or Ag-Pt alloy, and the matrix metal oxide comprises single and/or composite oxides of Al and Ce, rare earth element oxide except cerium and zinc oxide. The catalyst provided by the invention has high efficiency in catalytic oxidation of VOCs, is hopeful to be popularized to the preparation of various fixed bed catalytic materials, and has wide application prospect.

Inventors

  • ZHAO DONGYUE
  • Jiang Qiuqiao
  • WANG RUOYU
  • SONG HAITAO
  • LIU JUN

Assignees

  • 中国石油化工股份有限公司
  • 中国石油化工股份有限公司石油化工科学研究院

Dates

Publication Date
20260505
Application Date
20220713

Claims (20)

  1. 1. A catalyst for volatile organic removal, characterized in that the catalyst comprises a carrier and an active component supported on the carrier; The active component comprises noble metal and matrix metal oxide, wherein the noble metal is Ag-Pt alloy, and the matrix metal oxide comprises single and/or composite oxides of Al and Ce, rare earth element oxide except cerium and zinc oxide; The grain diameter of the Ag-Pt alloy is 1-8nm; based on the volume of the carrier, the load of Ag is 0.2-4g/L, and the load of Pt is 0.1-3g/L; The loading of the single and/or composite oxides of Al and Ce is 30-120g/L based on the volume of the carrier, the loading of the rare earth element oxides except cerium is 6-15g/L, and the loading of zinc oxide is 2-12g/L; The preparation method of the catalyst comprises the following steps: (1) Firstly mixing a precursor of noble metal, a reducing agent, a stabilizer and water to prepare a noble metal colloid solution; (2) Performing second mixing on the mixed solution of the matrix metal oxide precursor and the noble metal colloid solution to obtain catalyst slurry; (3) Coating catalyst slurry on the surface of a carrier, and performing first drying and ozone roasting treatment to obtain the catalyst loaded with active components; The condition of ozone roasting comprises roasting in ozone atmosphere at 350-550 deg.C for 1-3 hours.
  2. 2. The catalyst according to claim 1, wherein the total loading of the active component is 10 to 200g/L based on the volume of the support.
  3. 3. The catalyst according to claim 2, wherein the total loading of the active component is 40-160g/L based on the volume of the support.
  4. 4. A catalyst according to claim 1 to 3, wherein the noble metal is supported in an amount of 0.1 to 10g/L based on the volume of the support, and/or Ag loading of 0.4-2g/L, pt loading of 0.2-1g/L, and/or In the noble metal, the weight ratio of Ag to Pt is 0.1-4:1.
  5. 5. The catalyst according to claim 4, wherein the noble metal is supported in an amount of 0.3 to 7g/L based on the volume of the carrier, and/or In the noble metal, the weight ratio of Ag to Pt is 0.5-2.5:1.
  6. 6. The catalyst according to any one of claims 1 to 3, 5, wherein the loading of the single and/or composite oxides of Al and Ce is 60 to 95g/L, the loading of the rare earth element oxide other than cerium is 7 to 12g/L, the loading of zinc oxide is 4 to 10g/L, and/or The molar ratio of aluminum to cerium being 1-10:1, and/or The single and/or composite oxide of Al and Ce comprises Al-Ce composite oxide, and/or The rare earth element other than cerium is selected from at least one of La, pr and Y.
  7. 7. The catalyst of claim 6, wherein the molar ratio of aluminum to cerium is 4-8:1.
  8. 8. The catalyst according to claim 4, wherein the loading of the single and/or composite oxides of Al and Ce is 60 to 95g/L, the loading of the rare earth element oxides other than cerium is 7 to 12g/L, the loading of zinc oxide is 4 to 10g/L, and/or The molar ratio of aluminum to cerium being 1-10:1, and/or The single and/or composite oxide of Al and Ce comprises Al-Ce composite oxide, and/or The rare earth element other than cerium is selected from at least one of La, pr and Y.
  9. 9. The catalyst of claim 8, wherein the molar ratio of aluminum to cerium is 4-8:1.
  10. 10. The catalyst according to any one of claims 1 to 3, 5, 7 to 9, wherein the support is a structured support.
  11. 11. The catalyst according to claim 10, wherein the support has a cross-section having a pore density of 50-400 pores per square inch, an open cell content of 20-80%, and/or The carrier is at least one selected from cordierite, mullite, diamond, corundum, zirconia corundum, quartz, nepheline, feldspar, alumina and metal alloy.
  12. 12. The catalyst according to claim 4, wherein the carrier is a structured carrier.
  13. 13. The catalyst according to claim 12, wherein the support has a cross-section having a pore density of 50-400 pores per square inch, an open cell content of 20-80%, and/or The carrier is at least one selected from cordierite, mullite, diamond, corundum, zirconia corundum, quartz, nepheline, feldspar, alumina and metal alloy.
  14. 14. The catalyst according to claim 6, wherein the carrier is a structured carrier.
  15. 15. The catalyst according to claim 14, wherein the support has a cross-section having a pore density of 50-400 pores per square inch, an open cell content of 20-80%, and/or The carrier is at least one selected from cordierite, mullite, diamond, corundum, zirconia corundum, quartz, nepheline, feldspar, alumina and metal alloy.
  16. 16. A process for preparing a catalyst for volatile organic removal according to any one of claims 1 to 15, characterized in that the process comprises: (1) Firstly mixing a precursor of noble metal, a reducing agent, a stabilizer and water to prepare a noble metal colloid solution; (2) Performing second mixing on the mixed solution of the matrix metal oxide precursor and the noble metal colloid solution to obtain catalyst slurry; (3) Coating catalyst slurry on the surface of a carrier, and performing first drying and ozone roasting treatment to obtain the catalyst loaded with active components; Wherein the noble metal is a combination of Pt and Ag; The matrix metal oxide comprises a single and/or composite oxide of Al and Ce, a rare earth element oxide other than cerium and zinc oxide; The condition of ozone roasting comprises roasting in ozone atmosphere at 350-550 deg.C for 1-3 hours.
  17. 17. The method according to claim 16, wherein in the step (2), when the single and/or composite oxides of Al and Ce comprise Al-Ce composite oxides, the method for preparing the mixed liquid of the precursor of the matrix metal oxide comprises preparing the Al-Ce composite oxide, and then performing third mixing of the precursor of the Al-Ce composite oxide, the precursor of the rare earth element oxide other than cerium, the zinc oxide precursor and water to obtain the mixed liquid of the precursor of the matrix metal oxide.
  18. 18. The method according to claim 17, wherein in the step (2), the preparation method of the Al-Ce composite oxide comprises the steps of fourth mixing an Al salt, a Ce salt, a complexing agent and water to prepare a complexing agent solution, and then concentrating, second drying and roasting the complexing agent solution to obtain the Al-Ce composite oxide.
  19. 19. The process according to any one of claims 16 to 18, wherein in step (1) the precursor of the noble metal is a soluble salt of a noble metal, and/or The reducing agent is selected from at least one of ascorbic acid, borohydride and citrate, and/or The stabilizer is an organic amine.
  20. 20. The method of claim 19, wherein in step (1), the precursor of the noble metal is at least one of acetate, nitrate, and chloride, and/or The reducing agent is ascorbic acid, and/or The stabilizer is at least one selected from diethylamine, triethylamine and trimethylamine, and/or The amount of the reducing agent is 0.5 to 5mol and the amount of the stabilizer is 10 to 50mol, compared to 1mol of the noble metal.

Description

Catalyst for removing volatile organic compounds, preparation method and application thereof Technical Field The invention relates to the field of catalyst preparation, in particular to a catalyst for removing volatile organic compounds, a preparation method thereof and application of the catalyst in catalytic oxidation of VOCs. Background Volatile organic compounds (Volatile Organic Compounds, VOCs) are substances with boiling point of 50-260 ℃ and saturated vapor pressure higher than 133.3Pa at room temperature, and include hydrocarbons, aromatic hydrocarbons, halogenated hydrocarbons, aldehydes, ketones, polycyclic aromatic hydrocarbons and the like. VOCs are main pollutants of exhaust gas discharged in the production and processing processes of various industries such as petrochemical industry, printing, pharmacy and the like, have obvious peculiar smell, have stimulation or injury effect on human organs, can cause poisoning or canceration in serious cases, endanger human health, and can cause photochemical smog and other problems in the atmosphere to seriously destroy ecological environment. According to the principle, the control of VOCs pollution can be classified into adsorption method, incineration method, catalytic oxidation, biological method, membrane separation method, etc. The catalytic oxidation technology has the advantages of economy, high efficiency and the like, is one of the most promising technologies for removing VOCs, and the development of a high-performance catalytic oxidation catalyst is a key for realizing waste gas purification and green production. At present, the catalytic oxidation catalyst takes honeycomb inert materials (such as cordierite and the like) as carriers, and carries active components with low-temperature oxidation performance to realize the catalytic oxidation of VOCs. VOCs catalytic oxidation catalysts typically employ the noble metal platinum, palladium, as the active component. As disclosed in CN201811568947, an oxidation catalyst for catalytic combustion of VOCs and a preparation method thereof are disclosed, a noble metal-containing Pt active component is coated on the surface of a cordierite honeycomb ceramic carrier, and the catalyst can realize complete conversion of toluene at a temperature below 250 ℃. While platinum and palladium have excellent oxidation performance, the price is high, the cost of noble metal accounts for more than 60 percent of the total cost of the catalyst, and the activity and stability of a non-noble metal catalyst are poor, so that the market acceptance is still not high. How to improve the low-temperature oxidation performance of the catalyst with the cost being controlled at a low level is a problem to be solved in the art. Disclosure of Invention The invention aims to provide a catalyst capable of improving the low-temperature catalytic oxidation performance of VOCs (volatile organic compounds) under the condition of controlling the cost at a lower level, and particularly provides a catalyst for removing volatile organic compounds, a preparation method thereof and application of the catalyst in catalytic oxidation of VOCs. In order to achieve the above object, the first aspect of the present invention provides a catalyst for volatile organic compound removal, the catalyst comprising a carrier and an active component supported on the carrier; Wherein the active component comprises noble metal and matrix metal oxide, wherein the noble metal is Pt metal and/or Ag-Pt alloy, and the matrix metal oxide comprises single and/or composite oxides of Al and Ce, rare earth element oxide except cerium and zinc oxide. Preferably, the particle size of the Ag-Pt alloy is less than 10nm. Preferably, the single and/or composite oxides of Al and Ce comprise al—ce composite oxides. In a second aspect, the present invention provides a method for preparing a catalyst for volatile organic removal, the method comprising: (1) Firstly mixing a precursor of noble metal, a reducing agent, a stabilizer and water to prepare a noble metal colloid solution; (2) Performing second mixing on the mixed solution of the matrix metal oxide precursor and the noble metal colloid solution to obtain catalyst slurry; (3) Coating catalyst slurry on the surface of a carrier, and performing first drying and ozone roasting treatment to obtain the catalyst loaded with active components; Wherein the noble metal is a combination of Pt and Ag or Pt; the matrix metal oxide comprises a single and/or composite oxide of Al and Ce, a rare earth element oxide other than cerium, and zinc oxide. Preferably, in the step (2), when the single and/or composite oxides of Al and Ce comprise Al-Ce composite oxides, the preparation method of the mixed solution of the matrix metal oxide precursor comprises the steps of preparing the Al-Ce composite oxide, and then carrying out third mixing on the Al-Ce composite oxide, the precursor of the rare earth element oxide except cerium, the zinc oxide