Bromine-doped cerium-based SCR catalyst and preparation method thereof

Abstract

The invention provides a bromine-doped cerium-based SCR catalyst, which comprises 68-72 wt% of a carrier titanium dioxide, active components comprising cerium oxide and lanthanum oxide, 5-9 wt% of anauxiliary agent tungsten trioxide, and 1-2 wt% of a doping element bromine, wherein the cerium oxide content is 16-22 wt%, and the lanthanum oxide content is 2-6 wt%. The invention further provides apreparation method of the catalyst, wherein the preparation method specifically comprises: 1) co-precipitation; 2) material mixing; 3) extrusion; 4) drying; and 5) calcination. According to the present invention, the denitrification catalyst prepared by doping the bromine and using non-toxic cerium oxide and non-toxic lanthanum oxide as the active components has characteristics of no toxicity, wide temperature range, high activity, high sulfur resistance and high water resistance, and further has broad application prospect.

Description

technical field [0001] The invention relates to the field of SCR catalysts, in particular to a bromine-doped cerium-based SCR catalyst and a preparation method thereof. Background technique [0002] Nitrogen oxides (NO x ) is the main air pollutant, which will lead to the formation of photochemical smog and acid rain, which will seriously pollute the environment. Therefore, how to effectively eliminate nitrogen oxides has become an important topic of concern in the current environmental protection field. [0003] At present, stationary sources such as thermal power plants use ammonia selective catalytic reduction technology, which is mature and efficient. TiO 2 As the carrier, load a certain amount of V 2 o 5 、WO 3 and other components, this type of catalyst has good anti-sulfur performance, and its working temperature belongs to the medium temperature type. However, the active component V of the catalyst 2 o 5 The toxicity is very high, endangering the human body an...

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Problems solved by technology

The patent document with the application number CN201510401286.9 discloses a vanadium-free SCR denitration catalyst, which uses diatomaceous earth, molecular sieves and nano-titanium dioxide as carriers, and rare earth oxides (lanthanum oxide, cerium oxide), cross-linked chitosan The resin is the active center. Compared with the traditional vanadium catalyst, the biggest feature is that the catalyst is non-toxic. The patent has investigated the activity test of the sulfur-containing atmosphere, but has not investigated the water-containing atmosphere, which limits the scope of application of the catalyst.

The patent document with the application number CN201110445415.6 discloses an activated carbon-supported rare earth metal oxide reduction denitration catalyst. The catalyst uses activated carbon as the denitration catalyst carrier, and the rare earth metal cerium, or the dual component of lanthanum and cerium, is the active component of the catalyst. The advantage of the catalyst is that the denitrification reaction does not need to add NH3, CO and other reducing gases as reducing agents. The unique chemical properties of activated carbon make the catalyst exhibit good denitrification performance under suitable conditions. When the reaction temperature is above 500 ° C, the catalyst shows good performance Denitrification performance, but the medium temperature conditions were not investigated, and the gas atmosphere was only NO, and the sulfur-containing and water-containing atmosphere was not investigated, the scope of use of the catalyst was limited

It can be seen that the existing out-of-stock catalysts have the following defects: poisonous, narrow applicable temperature range, poor sulfur resistance and water resistance