Selective catalytic reduction (SCR) catalyst and preparation method thereof

A technology of SCR catalyst and oxide, which is applied in the direction of catalyst carrier, chemical instrument and method, physical/chemical process catalyst, etc., can solve the problems of catalyst wear, can not meet the purification, affect the service life and other problems

Inactive Publication Date: 2014-03-12
柳景惠
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] But now, the core component of the system, the SCR catalytic converter, still has some deficiencies and problems: the temperature of the exhaust gas is mostly lower than 200°C when the vehicle is idling or at low speed, while the temperature window of the traditional vanadium-titanium-tungsten SCR is 280°C~ 400°C, so the catalyst cannot meet the NO x purification; and most SCR catalysts are supported by TiO 2 Or zeolite and other porous structures, there are also research reports using Al 2 o 3 , Activated carbon and activated coke are used as the carrier of SCR catalyst. The actual engineering test proves that although these carriers have good adaptability, they are sensitive to sulfur and water vapor due to their simple composition, and the catalyst will be worn by dust in the flue gas, affecting service life

Method used

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  • Selective catalytic reduction (SCR) catalyst and preparation method thereof
  • Selective catalytic reduction (SCR) catalyst and preparation method thereof
  • Selective catalytic reduction (SCR) catalyst and preparation method thereof

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preparation example Construction

[0027] The present invention also provides a preparation method of the above-mentioned SCR catalyst, comprising the following steps: S1) mixing the soluble silicon source and the soluble titanium source in an alcohol solvent, adding water, stirring, and standing to obtain a gel; S2) mixing the The above gel is dried and roasted to obtain TiO 2 -SiO 2 Composite oxide support; S3) Dissolve soluble metal salt and soluble cerium salt in water, then add TiO 2 -SiO 2 The composite oxide carrier is stirred until powder solid is obtained, dried and roasted to obtain an intermediate product; the corresponding metal oxide of the metal in the soluble metal salt is a solid acid; the quality of the corresponding metal oxide of the soluble metal salt is TiO 2 -SiO 2 1-10% of the mass of the composite oxide support; the corresponding CeO of the soluble cerium salt 2 mass TiO 2 -SiO 2 0% to 10% of the mass of the composite oxide carrier; S4) adding the intermediate product to a solution...

Embodiment 1

[0049] 1.1 Mix and stir 60ml absolute ethanol, 12ml butyl titanate and 12ml tetraethyl orthosilicate evenly, and then according to the ratio of the amount of butyl titanate and ethyl orthosilicate to the amount of water, Add deionized water at a ratio of 1:5, continue to stir for 5 hours, and leave to age for 48 hours to obtain a gel; dry the obtained gel in an oven at 80°C for 14 hours, and bake it in a muffle furnace at 300°C for 10 hours to obtain TiO 2 -SiO 2 Composite oxide carrier.

[0050] 1.2 Add 3.04g of ammonium metatungstate and 3.26g of cerium nitrate into 50ml of deionized water, stir for 2h, then add 20g of TiO obtained in 1.1 2 -SiO 2 The composite oxide carrier was continuously stirred at 60°C until it was dried to obtain a solid powder, which was dried in an oven at 80°C for 14 hours, calcined in a muffle furnace at 300°C for 10 hours, and ground to obtain an SCR catalyst.

[0051] Perform a performance test on the SCR catalyst obtained in 1.2: put the SCR...

Embodiment 2

[0057] 2.1 Mix 60ml of absolute ethanol, 12ml of butyl titanate and 20ml of sodium silicate solution with a mass fraction of 60% and stir evenly, and then mix and mix according to the amount of butyl titanate and tetraethyl orthosilicate and the substance of water Add deionized water at a ratio of 1:5, continue to stir for 5 hours, and leave to age for 48 hours to obtain a gel; dry the obtained gel in an oven at 150°C for 8 hours, and dry it in a muffle furnace for 700 ℃ roasting for 2h to get TiO 2 -SiO 2 Composite oxide carrier.

[0058] 2.2 Add 3.04g of niobium oxalate into 50ml of deionized water, stir for 2h, then add 20g of TiO obtained in 2.1 2 -SiO 2 The composite oxide carrier was continuously stirred at 60°C until it was dried to obtain a powder solid, which was dried in an oven at 150°C for 8 hours, and calcined in a muffle furnace at 700°C for 2 hours to obtain an intermediate product.

[0059] 2.3 will be 1.05gV 2 o 5 Dissolve the powder in 10ml of oxalic ac...

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Abstract

The invention provides a selective catalytic reduction (SCR) catalyst and a preparation method thereof. The SCR catalyst comprises a TiO2-SiO2 composite oxide carrier, a metal oxide solid acid, V2O5 and CeO2. Compared with the existing SCR catalyst, the SCR catalyst has the advantages that SiO2 is added, so phase change of TiO2 at high temperature can be inhibited and the heat stability of the catalyst is enhanced; the SiO2 has more specific surface area than that of the TiO2, so the specific surface area of the catalyst can be increased, active components are dispersed well, and the activity of the catalyst is further improved through the interaction of the metal and the carrier; the SiO2 has excellent heat stability, so the using temperature window of the SCR catalyst can be widened by inhibiting the phase change of the carrier at high temperature and inhibiting reduction of the specific surface area; and the active components such as the CeO2 are added, so the catalytic activity of the catalyst at a lower temperature can be improved by enhancing the oxidizing capacity at a low temperature.

Description

technical field [0001] The invention belongs to the technical field of catalyst preparation and environmental catalysis, and in particular relates to an SCR catalyst and a preparation method thereof. Background technique [0002] For the sake of fuel economy, diesel engines are more and more widely used due to their low fuel consumption and high power ratio. However, the nitrogen oxides NO produced by the high pressure and high temperature in the diesel engine cylinder x It has brought serious environmental problems and exacerbated the deterioration of air quality. At present, among the main pollutants in our country's atmosphere, NO from automobile exhaust x It has become one of the most important sources, so my country has continuously improved the corresponding emission standards for road vehicles equipped with diesel engines. [0003] At present, in the purification of diesel vehicle exhaust NO x On the one hand, selective catalytic reduction (SCR) technology is the ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01J23/30B01J23/20B01J23/28B01J32/00
Inventor 柳景惠
Owner 柳景惠
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