MnOx-TiO2 composite oxide with rutile TiO2 serving as matrix

Abstract

The invention relates to MnOx-TiO2 composite oxide with rutile TiO2 serving as a matrix and application of the MnOx-TiO2 composite oxide with rutile TiO2 serving as the matrix in fume low-temperature Selective Catalytic Reduction (SCR) denitration. In the fume low-temperature SCR denitration, the MnOx-TiO2 composite oxide serves as a catalyst. The method comprises steps of adding titanium tetrachloride to an acidic aqueous solution under ice-water bath slowly and dropwisely; subjecting TiCl4 and water to the reaction to produce transparent and colorless hydrated TiO6; hydrolyzing the hydrated TiO6 at the room temperature and on the acidic condition; generating rutile TiO2 precursor micelles; adding soluble manganese salt to the precursor micelles and conducting dispersion with stirring; conducting heat processing; and obtaining the nano MnOx-TiO2 composite oxide with rutile TiO2 serving as the matrix and with MnOx serving as an active component. MnOx has high dispersity on the rutile TiO2 matrix. Therefore, the MnOx-TiO2 composite oxide can serve as the low-temperature SCR denitration catalyst and has high catalytic activity. The removing rate of NO can reach 100 mol% under the condition that the NO concentration is 800ppm, the reaction temperature is 160 DEG C and the space speed is 50,000 hours-1.

Description

technical field [0001] The present invention relates to a catalyst mainly used for flue gas selective catalytic reduction (Selective Catalytic Reduction, SCR) denitrification, in particular to a rutile-type TiO 2 MnO as the matrix x -TiO 2 composite oxide catalyst. Background technique [0002] with V 2 o 5 / TiO 2 The high-temperature SCR denitrification method as a catalyst has been widely used in the field of flue gas denitrification in thermal power plants. In order to further improve the denitration efficiency, reduce the denitration operating temperature, prolong the service life of the catalyst, and reduce the operating cost of the denitration system, in recent years, the research and development of catalysts for low-temperature SCR denitration has become a hot spot in the industry. Studies have shown that MnO x It has high low-temperature SCR denitrification activity. Due to its mature preparation process, large specific surface area and strong anti-poisoning ...

AI Technical Summary

Problems solved by technology

MnO prepared by sol-gel method x / TiO 2 The specific surface area of ​​the catalyst is large, and MnO x Active material and anatase TiO 2 matrix to form highly dispersed MnO x -TiO 2 Composite oxide structure, so it has the highest low-temperature SCR denitrification activity, but the raw materials used in this preparation method are expensive, and the preparation process is complicated, so it is difficult for practical application

[0003] According to literature research, it is found that the currently prepared MnO x / TiO 2 In the catalyst, TiO as a support 2 Most of them are anatase type, and the crystal form of anatase type has poor thermal stability, and usually converts to rutile type at 400-1000 °C, especially during catalyst roasting or low-temperature SCR reaction, MnO on the surface of the catalyst x will induce and promote surface anatase TiO 2 rutile TiO 2 crystallization, the final formation of MnO x / TiO 2 The surface structure of the catalyst is MnO x Dispersed in rutile TiO 2 on top

And the rutile TiO formed by crystallization 2 Positively small specific surface area, resulting in MnO x The dispersion and exposure of species on the catalyst surface is reduced, thereby reducing the MnO x / TiO 2 The low-temperature SCR denitrification activity of the catalyst is not conducive to the long-term efficient and stable operation of the catalyst

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