SCR catalyst applicable to medium-and-high-temperature and high-humidity flue gas conditions and preparation method thereof

Abstract

The invention relates to an SCR catalyst applicable to medium-and-high-temperature and high-humidity flue gas conditions and a preparation method thereof, belonging to the technical field of catalystpreparation. The preparation method comprises the following concrete steps: placing a cerium precursor, a molybdenum precursor and a carrier namely TiO2 with calculated amounts into a ball mill tank,carrying out ball milling for 1 to 6 h, and calcining a uniformly-mixed powder in a muffle furnace by two steps so as to obtain a MoO3-CeO2 / TiO2 composite oxide catalyst, wherein the content of CeO2 accounts for 5 to 40 wt% of the total amount of a cerium-titanium composite oxide, and the content of MoO3 accounts for 0 to 10 wt% of the total amount of a molybdenum-cerium-titanium composite oxide.The SCR catalyst provided by the invention maintains an NO conversion rate to be 85% or above in a medium and high temperature range (250 to 500 DEG C) under a high-humidity flue gas condition. The preparation method provided by the invention has the advantages of simple preparation process, easily-controllable conditions, low raw material price, and potential application value in the field of denitration.

Description

technical field [0001] The invention relates to a preparation method of an SCR catalyst applied to medium-high temperature and high humidity flue gas conditions and its application in ammonia selective catalytic reduction of nitrogen oxides, belonging to the technical field of catalyst preparation. Background technique [0002] Nitrogen oxides (NO x ) is a major air pollutant, and it is one of the important culprits that cause severe weather such as acid rain, photochemical smog, and smog. In addition, these nitrogen oxides enter the stratosphere and can generate O with ozone under the catalytic action of light. 3 A chemical reaction occurs that destroys the ozone layer. Ammonia selective catalytic reduction (Selective Catalysis Reduction, NH 3 -SCR) is currently the most effective flue gas denitrification technology that has been commercialized, and its commercial catalysts are mainly vanadium-titanium-based (V 2 o 5 -WO 3 / TiO 2 or V 2 o 5 -MoO 3 / TiO 2 ). Has ...

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Problems solved by technology

However, the flue gas temperature window for traditional vanadium-titanium-based SCR catalysts is only 300°C~

[0003] 450°C, when the temperature exceeds the above range, the activity of the vanadium-titanium-based catalyst will decrease significantly, and the active components of the catalyst will easily lose into the atmosphere, which is harmful to the human body and the environment; waste catalysts have been included in the

However, so far there are few reports on SCR catalysts suitable for high-temperature and high-humidity flue gas conditions of gas turbines.

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