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CN-122006737-A - Denitration catalyst with high denitration efficiency and preparation method thereof

CN122006737ACN 122006737 ACN122006737 ACN 122006737ACN-122006737-A

Abstract

The invention relates to the technical field of environmental catalysis, and discloses a denitration catalyst with high denitration efficiency and a preparation method thereof, wherein the denitration catalyst takes TiO 2 -WO 3 -SiO 2 as a composite carrier, V 2 O 5 as a main active component, cuO and CeO 2 as auxiliary active components, and the mass percentage of each component is ：V 2 O 5 1.5-3.0%、CuO2.0-4.0%、CeO 2 1.0-2.5%、WO 3 5.0-8.0%、SiO 2 3.0-5.0%,, and the balance is TiO2. According to the invention, the specific surface area and the number of active sites of the catalyst are obviously improved by optimizing the proportion of the composite carrier and the loading mode of the active components, the adsorption and activation capacity of the catalyst to NOx is enhanced, and the catalyst has excellent sulfur resistance, water resistance and thermal stability. The preparation method disclosed by the invention is simple in process, controllable in cost, good in repeatability and suitable for industrial mass production.

Inventors

  • LIU GUANLI
  • LI XIAOLIN
  • GE CHENGMIN
  • CHEN HAO
  • WANG LIANG

Assignees

  • 山东东源新材料科技有限公司

Dates

Publication Date
20260512
Application Date
20260123

Claims (8)

  1. 1. A denitration catalyst with high denitration efficiency is characterized by taking TiO 2 -WO 3 -SiO 2 as a composite carrier, taking V 2 O 5 as a main active component, taking CuO and CeO 2 as auxiliary active components, and taking the balance of ：V 2 O 5 1.5-3.0%、CuO2.0-4.0%、CeO 2 1.0-2.5%、WO 3 5.0-8.0%、SiO 2 3.0-5.0%, as TiO 2 according to mass percent.
  2. 2. The high denitration efficiency denitration catalyst according to claim 1, wherein the TiO 2 is anatase type, has a specific surface area of 100 to 150m2/g, and has a particle diameter of 20 to 50nm.
  3. 3. The denitration catalyst with high denitration efficiency according to claim 1, wherein the specific surface area of the catalyst is 120-180m2/g, the pore volume is 0.3-0.6cm3/g, and the average pore diameter is 8-15nm.
  4. 4. A method for preparing the high denitration catalyst as claimed in any one of claims 1 to 3, characterized by comprising the steps of: S1, preparing a composite carrier, namely dissolving tetrabutyl titanate in absolute ethyl alcohol, uniformly stirring to obtain a titanium source solution, slowly dripping a mixed solution containing ammonium tungstate and tetraethoxysilane into the titanium source solution, simultaneously adding dilute nitric acid to adjust the pH value of a system to 2-3, continuously stirring for 1-2 hours, placing the mixture in a water bath at 60-80 ℃ for constant temperature ageing for 4-6 hours to obtain gel, placing the gel in a baking oven at 100-120 ℃ for drying for 12-16 hours, then roasting in a muffle furnace at 500-600 ℃ for 3-5 hours, cooling, and grinding to 100-200 meshes to obtain the TiO 2 -WO 3 -SiO 2 composite carrier; S2, preparing an active component solution, namely dissolving ammonium metavanadate, copper nitrate and cerium nitrate in deionized water, adding citric acid serving as a complexing agent, and stirring until the citric acid is completely dissolved to obtain an active component mixed solution, wherein the molar ratio of the citric acid to metal ions is 1.2-1.5:1; S3, impregnating and loading, namely adding the composite carrier prepared in the step S1 into the active component mixed solution prepared in the step S2, stirring and impregnating for 4-8 hours at 30-50 ℃ by adopting an isovolumetric impregnation method, and then standing for 12-24 hours; S4, drying and roasting, namely placing the sample immersed in the step S3 into a drying oven at 100-120 ℃ for drying, then placing into a muffle furnace, raising the temperature to 450-550 ℃ at a temperature raising rate of 5-10 ℃ per minute, roasting for 4-6 hours, and cooling to obtain the denitration catalyst with high denitration efficiency.
  5. 5. The method for preparing a denitration catalyst with high denitration efficiency according to claim 4, wherein in the step S1, the volume ratio of tetrabutyl titanate to absolute ethyl alcohol is 1:3-1:5, and the mass ratio of ammonium tungstate to tetraethoxysilane in the mixed solution containing ammonium tungstate and tetraethoxysilane is 2-3:1.
  6. 6. The method for preparing a denitration catalyst with high denitration efficiency according to claim 4, wherein in the step S2, the addition amounts of ammonium metavanadate, copper nitrate and cerium nitrate are determined according to the mass percentages of V 2 O 5 , cuO and CeO 2 in the target catalyst.
  7. 7. The method for preparing a denitration catalyst with high denitration efficiency according to claim 4, wherein in the step S4, the roasting process is divided into three stages, namely, a first stage of raising the temperature from room temperature to 200 ℃, the temperature is kept for 1h, a second stage of raising the temperature from 200 ℃ to 350 ℃, the temperature is kept for 1.5h, and a third stage of raising the temperature from 350 ℃ to 450-550 ℃ and the temperature is kept for 2-3h.
  8. 8. The method for preparing a denitration catalyst with high denitration efficiency as claimed in claim 4, wherein in the step S4, the drying time is 12 to 16 hours.

Description

Denitration catalyst with high denitration efficiency and preparation method thereof Technical Field The invention relates to the technical field of environmental catalysis, in particular to a denitration catalyst with high denitration efficiency and a preparation method thereof. Background With the rapid development of industry, a great deal of flue gas containing nitrogen oxides (NOx) is generated by the massive consumption of fossil fuels such as coal, fuel oil and the like, and the NOx is an important pollutant causing environmental problems such as acid rain, photochemical smog, ozone cavities and the like, so that the ecological environment and the human health are seriously endangered. Therefore, controlling NOx emissions has become one of the important tasks of environmental protection. At present, in the flue gas denitration technology, the Selective Catalytic Reduction (SCR) technology is widely applied due to the advantages of high denitration efficiency, mature technology and the like. The core of the SCR technology is a denitration catalyst, and the performance of the denitration catalyst directly determines the denitration efficiency. The existing SCR denitration catalyst mainly takes TiO 2 as a carrier, V 2O5 as a main active component and WO 3 or MoO 3 as an auxiliary active component, and the catalyst has good denitration activity in the temperature range of 300-400 ℃, but has the problems of low denitration efficiency at low temperature (< 250 ℃), narrow temperature window, sulfur resistance, water resistance and the like to be improved. With the increasing strictness of environmental standards, higher requirements are put on the performance of denitration catalysts, and it is required to develop a denitration catalyst having high denitration efficiency, excellent sulfur resistance and water resistance and thermal stability in a wide temperature range. In order to solve the above problems, researchers have made a great deal of research. For example, rare earth metals such as Ce, cu and the like or transition metals are introduced into the catalyst as auxiliary active components to promote the low-temperature activity of the catalyst, and the composite carrier is prepared by optimizing the carrier composition to enhance the specific surface area and the stability of the carrier. However, in the prior art, the proportion design of the composite carrier is unreasonable, and the synergistic effect between active components cannot be fully exerted, so that the denitration efficiency and stability of the catalyst still need to be further improved. Therefore, developing a denitration catalyst with optimized formula and simple preparation process and high denitration efficiency has important practical significance. Disclosure of Invention In order to overcome the defects of the prior art, the invention aims to provide a denitration catalyst with high denitration efficiency and a preparation method thereof, and solve the problems of poor low-temperature activity, narrow temperature window and insufficient sulfur and water resistance of the denitration catalyst in the prior art. In order to achieve the above purpose, the invention is realized by adopting the following technical scheme: The denitration catalyst with high denitration efficiency adopts the technical scheme that TiO 2-WO3-SiO2 is used as a composite carrier, V 2O5 is used as a main active component, cuO and CeO 2 are used as auxiliary active components, and the balance of the components is TiO 2 according to the mass percentage of ：V2O51.5-3.0%、CuO2.0-4.0%、CeO21.0-2.5%、WO35.0-8.0%、SiO23.0-5.0%,. According to the invention, by reasonably designing the composition of the composite carrier, WO 3 and SiO 2 are compounded with TiO 2, the acidity and the thermal stability of the catalyst can be enhanced by WO 3, the specific surface area and the pore structure of the carrier can be obviously improved by SiO 2, the two are synergistic with TiO 2, and a good carrier environment is provided for the loading of active components. Meanwhile, cuO and CeO 2 are introduced as auxiliary active components, the CuO has excellent low-temperature oxidation-reduction performance, the low-temperature denitration activity of the catalyst can be improved, ceO 2 has rich oxygen vacancies and good oxygen storage capacity, the electron transfer between the active components and a carrier can be promoted, the dispersibility of the active components is enhanced, the synergistic effect with V 2O5 and CuO is achieved, the temperature window of the catalyst is further widened, and the denitration efficiency and the sulfur-resistant and water-resistant performance are improved. Further, the TiO 2 is anatase type, the specific surface area is 100-150m < 2 >/g, the particle size is 20-50nm, and the anatase type TiO 2 has higher specific surface area and catalytic activity and is suitable for being used as a carrier of an SCR denitration catalyst. Further, the specific su