Effects of cerium and vanadium on the activity and selectivity of MnOx-TiO2 catalyst for low-temperature NH3-SCR

被引：42

作者：

Wu Xiaodong ^{[1
]}

Si Zhichun ^{[1
]}

Li Guo ^{[1
]}

Weng Duan ^{[1
]}

Ma Ziran ^{[1
]}

机构：

[1] Tsinghua Univ, Dept Mat Sci & Engn, State Key Lab New Ceram & Fine Proc, Beijing 100084, Peoples R China

来源：

JOURNAL OF RARE EARTHS | 2011年 / 29卷 / 01期

关键词：

MnOx-TiO2; modification; selective reduction of NO; acid sites; rare earths; MANGANESE OXIDE CATALYSTS; NITRIC-OXIDE; TRANSITION-METALS; NO REDUCTION; NH3; AMMONIA; MN; TIO2; SCR; MNOX/TIO2;

D O I：

10.1016/S1002-0721(10)60403-6

中图分类号：

O69 [应用化学];

学科分类号：

081704 ;

摘要：

MnOx-TiO2, CeO2-MnOx-TiO2 and V2O5-MnOx-TiO2 catalysts for low-temperature NH3-SCR were prepared by sol-gel method. The results showed that both cerium and vanadium prevented the transformation of anatase TiO2 to the rutile phase. The addition of vanadium oxide induced the segregation of crystalline Mn2O3, which contributed little to low-temperature SCR and ammonia oxidation, from the MnOx-TiO2 solid solutions. However, the selectivity of the V-containing catalyst was almost 100% due to the decreased ammonia consumption and enhanced adsorption capacity of ammonia on Bronsted acid sites at relatively high temperatures. The electron-donating effect of cerium reduced the Mn4+/Mn3+ ratio to some extent, resulting in a decreased activity for ammonia oxidation. This, in combination with the enhanced ammonia adsorption capacity by Cen+ as additional Lewis acid sites, endowed the Ce-doped catalyst a higher N-2 selectivity than MnOx-TiO2 despite the slightly elevated light-off temperature for NO conversion.

引用

页码：64 / 68

页数：5

共 23 条

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