Fe-M/CNTs denitration catalyst, preparation method and application of catalyst in ammonia selective catalytic reduction to nitrogen oxide

Abstract

The invention discloses a Fe-M/CNTs denitration catalyst, a preparation method and application of the catalyst in ammonia selective catalytic reduction to nitrogen oxide and belongs to the technical field of environmental catalyzed purification. The catalyst is prepared by adopting an impregnation method simple in operation and high in repeatability, namely a suitable iron source and a molybdenum source or a tungsten source are evenly impregnated on the surface of a carbon nanotube subjected to acid treatment, drying and calcination are performed, and then the denitration catalyst is obtained. The prepared Fe-M/CNTs denitration catalyst has high surface active particle dispersion, high low-medium-temperature catalytic activity and a wide operatable temperature window and has the NOx conversion rate of 90% above within the 250-400 DEG C, the N2 selectivity is kept to 85% or above, the flue gas sulfur oxide and water impact resisting capability I strong, and the Fe-M/CNTs denitration catalyst is suitable for a fixed-source nitric oxide purification device represented by coal-fired power plant flue gas and has a wide industrial application prospect.

Description

technical field [0001] The invention belongs to the technical field of environmental catalytic purification, and relates to an Fe-M / CNTs denitrifying agent, a preparation method and its application in ammonia selective catalytic reduction of nitrogen oxides technology. Background technique [0002] Nitrogen oxides mainly come from coal-fired power plant flue gas and vehicle exhaust emissions. Their transformation in the atmosphere will cause a series of environmental pollution problems such as smog, photochemical smog, and acid rain, threatening human health. Among many nitrogen oxide removal technologies, selective catalytic reduction of nitrogen oxides by ammonia (NH 3 -SCR) technology has the advantages of high denitrification efficiency, small secondary pollution, and low reaction energy efficiency, and is widely used. Because it can effectively avoid the impact of high-concentration sulfur oxides and dust and prolong the service life of the catalyst, the deployment and...

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Problems solved by technology

[0004] There have been relevant reports in Chinese patent CN105107514A about the Fe-Mo composite oxide catalyst applied in the SCR technology, but this invention adopts a more complicated sol-gel method, and only under lower space velocity conditions (4000h -1 )NO x The conversion rate is good; CN105214679A discloses a catalyst containing 6 components such as Fe and Mo prepared by co-precipitation method, although the catalyst has more than 80% NO at 150°C x Conversion rate, but organic silicon solvent is used in the preparation process, the use of organic solvent will not only increase the preparation cost of the catalyst, but also cause pollution to the environment

Chinese patents CN104941655A and CN103877986A both disclose Fe-W composite oxide catalysts prepared by co-precipitation method, and their denitrification efficiency and N 2 The selectivity reaches more than 90%, but the preparation of the composite oxide catalyst uses a large amount of raw materials, which is not economically beneficial

[0005] At present, there are few patents and research reports on the use of carbon nanotubes to support iron and molybdenum or iron and tungsten two-component catalysts, effectively broaden the denitrification operating window of the catalyst, and improve the catalyst's ability to resist the impact of sulfur oxides

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