Medium-low temperature SCO denitration catalyst and preparation method thereof

Abstract

The invention discloses a medium-low temperature SCO denitration catalyst and a preparation method thereof, and relates to a two-step method and a three-step method. A catalyst material is solid powder and comprises the following substances in percentage by weight: 40 to 60 percent of manganese oxide, 40 to 60 percent of iron oxide and 0.0003 to 0.005 percent of graphene. The two-step method comprises the following steps: (1) mixing potassium permanganate, concentrated hydrochloric acid, ultrapure water and reduced graphene oxide, and carrying out a reaction to obtain an intermediate product;and (2) filtering, washing and drying a product obtained after a hydrothermal reaction of the product obtained in the previous step, manganese acetate, ferric nitrate, polyethylene glycol 1000 and potassium permanganate to obtain the catalyst. According to the three-step method, on the basis of the two-step method, the product in the previous step is subjected to a hydrothermal reaction with manganese acetate, ferric nitrate, polyethylene glycol 1000 and potassium permanganate, and the product is filtered, washed and dried. The catalytic oxidation efficiency of the two-step catalyst to NO at 200 DEG C reaches 50%, and the catalytic oxidation efficiency of the three-step catalyst can reach 80% or above. Compared with an existing ferromanganese catalyst, the low-temperature catalytic efficiency of the catalyst is higher, the industrial requirement can be better met, and the catalyst has great potential application prospects in the field of low-temperature denitration.

Description

Technical field: [0001] The invention belongs to the technical field of NOx removal, and relates to two kinds of SCO denitrification catalysts at medium and low temperatures and a preparation method thereof. Background technique: [0002] Nitrogen oxides are important substances that cause air pollution, among which NO and NO 2 Mainly, their large-scale discharge will not only cause a series of environmental problems such as smog, acid rain, near-surface atmospheric ozone destruction, eutrophication of surface water, and photochemical smog, but also stimulate the human central nervous system and respiratory system, seriously threatening human health. . At present, the flue gas denitrification technology mainly used in nitrogen oxide treatment technology is divided into two categories: dry method and wet method: dry method mainly includes selective catalytic reduction (SCR) method, selective non-catalytic reduction (SNCR) method, The wet method mainly includes liquid absorp...

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Problems solved by technology

Molecular sieves have large specific surface area and unique pore structure, but the NO catalytic oxidation activity of molecular sieve catalysts is not high at low temperatures, and only show high-temperature activity. However, limited by thermodynamic equilibrium, NO catalytic activity is not high at high temperatures. The cost is high, so the industrial application of molecular sieves has not yet been realized

Activated carbon catalysts can also catalyze the oxidation of NO, but under low temperature conditions, the reaction process of activated carbon catalytic oxidation of NO requires a long stabilization time, the reaction rate is slow, and the water resistance of activated carbon catalysts is poor, and the amount of catalyst used is extremely large

Noble metal catalysts have relatively high activity, but they are expensive, and the cost of industrial application is high