Environment-friendly NOx selective catalytic reduction catalyst and preparation method thereof

Abstract

The present invention relates to an environment-friendly NOx selective catalytic reduction catalyst and a preparation method thereof, wherein the catalyst comprises, by mass : 5 wt % to 30 wt % of CeO2, 45 wt % to 20 wt % of ZrO2, 35 wt % to 20 wt % of TiO2, 5 wt % to 10 wt % of SiO2, and 10 wt % to 20 wt % of WO3. A soluble cerium salt, a zirconium salt, a titanium salt, a silicon salt and a tungsten salt which are used as raw materials, an alkali which is used as a coprecipitator, and polyethylene glycol which is used as a thickening agent, are dried and roasted to obtain the catalyst. When the catalyst is at the temperature from 220 DEG C to 560 DEG C, the conversion rate of NOx can reach above 80%, especially at 250 DEG C to 500 DEG C, the conversion rate of NOx can reach above 95%. Further, the catalyst is provided with strong capability of resisting to hot water aging and SO2 poisoning, the activity of SCR still maintaining above 80% after the hot water aging treatment and the sulfur ageing treatment. The catalyst is advantaged in simple preparation process, convenient operation and low cost, and can meet and achieve the standards of existing vehicle exhaust purification and the needs of actual production.

Description

technical field [0001] The present invention relates to a kind of preparation method of selective catalytic reduction catalyst, more specifically, relate to an environment-friendly NO x Selective catalytic reduction catalyst and preparation method. Background technique [0002] Harmful substances in the atmosphere—nitrogen oxides have brought about global air pollution problems. Nitrogen oxides (NO x ) usually refers to NO and NO 2 It is mainly derived from the combustion process of fossil fuels, including fixed source emissions such as coal-fired power plant flue gas and mobile source emissions such as motor vehicle exhaust. In recent years, my country's NO x The continuous increase of emissions has caused a huge threat and poisonous effect on the ecological environment and human health. With the development of the national economy, population growth and the acceleration of urbanization, the emission of nitrogen oxides in my country will continue to increase in the fut...

AI Technical Summary

Problems solved by technology

V 2 o 5 -WO 3 -TiO 2 The catalyst has shortcomings such as insufficient activity at low temperature and poor thermal stability at high temperature

In addition, the V / W / Ti catalytic system also has vanadium volatilization at high temperature, which is likely to cause environmental problems of vanadium pollution.

The main problems of transition metal-based molecular sieve catalysts include: poor hydrothermal stability, low temperature sulfur poisoning and HC poisoning

[0005] At present, the environment-friendly oxide catalysts are mainly low-temperature SCR catalysts, which still have insufficient high-temperature activity, poor resistance to sulfur poisoning, and poor hydrothermal stability. window, it is particularly necessary to prepare oxide catalysts with high resistance to sulfur poisoning and hydrothermal stability.

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