Cerium-zirconium-tungsten composite oxide catalyst as well as preparation method and usage thereof

Abstract

The invention relates to a cerium-zirconium-tungsten composite oxide catalyst used for carrying out selective catalytic reduction on nitric oxide by ammonia, as well as a preparation method and usage thereof. The catalyst is a composite metal oxide formed by three types of metal including cerium, zirconium and tungsten. The catalyst adopts non-toxic and harmless raw materials; the cerium-zirconium-tungsten composite oxide catalyst which can adapt to high space velocity reaction condition and has the characteristics of being excellent in catalytic activity, high in N2 generation selectivity, wide in operating temperature window and the like can be prepared by using a simple and practicable method; and the cerium-zirconium-tungsten composite oxide catalyst is suitable for a nitric oxide catalytic purification device used for a moving source represented by diesel exhaust and a fixed source represented by flue gas of a coal-fired power plant.

Description

technical field [0001] The present invention relates to a catalyst, in particular to a cerium-zirconium-tungsten composite oxide catalyst used for catalytic purification of nitrogen oxides, in particular to a mobile source represented by diesel vehicle exhaust and flue gas of coal-fired power plants as a representative Representative cerium-zirconium-tungsten composite oxide catalysts for catalytic purification of stationary source nitrogen oxides. Background technique [0002] With the increasing shortage of global oil resources, CO 2 With increasing pressure to reduce emissions, more and more attention has been paid to diesel vehicles with good fuel economy and strong power, and the global trend of "dieselization" of vehicle power has become increasingly obvious. However, compared with gasoline vehicles equipped with three-way catalysts with relatively mature technology, the NO in the exhaust of diesel vehicles using lean burn technology x And PM become the bottleneck re...

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Problems solved by technology

[0005] For existing NH 3 -The shortcomings of SCR catalysts, in order to solve the narrow operating temperature window of the metal oxide catalyst system, poor low temperature activity, N 2 Due to the shortcomings of low selectivity and sensitivity to reaction space velocity, the present invention provides a cerium-zirconium-tungsten composite oxide catalyst for the first time. Compared with the applicant's previous application, the catalytic activity and high-temperature sintering resistance of the catalyst are significantly improved , can be used as a mobile source represented by diesel vehicle exhaust and a stationary source of NO represented by flue gas from coal-fired power plants x Catalytic purification, preferably for NO in diesel vehicle exhaust x Catalytic purification, widening the NH 3 -Optional range of SCR catalysts

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