含稀土NH_3-SCR脱硝催化剂研究进展

Advances in Rare Earth-containing Catalysts for the Selective Catalytic Reduction of NO_x with NH_3

氨选择性催化还原(NH_3-SCR)是目前国际上应用最为广泛的燃煤电厂烟气脱除NO_x技术,而高效催化剂的研制和开发是该技术的核心。近年来,稀土氧化物尤其是Ce O_2因其可以提高催化剂的热稳定性及脱硝性能、改善催化剂的抗SO_2和H_2O中毒能力而受到了国内外的普遍关注。因此,本文综述了用于NH_3-SCR反应的含稀土催化剂的研究现状,重点介绍了用于传统NH_3-SCR与低温NH_3-SCR的催化剂类型,阐明了含稀土催化剂在该反应过程中的机理,并对未来含稀土脱硝催化剂可能的研究与发展方向进行了展望。

The selective catalytic reduction of NOx with NH3 （NH3-SCR） is considered to be the most promising technolo- gy to remove NOx from flue gases produced by coal fired power plants. The research and development of efficient catalysts are the key point in this catalytic purification technology. The rare earth-containing catalysts, especially ceria-containing catalysts, have attracted much attention due to its superior thermal stability, higher activity for SCR of NO and less sensitive to SO2 and H2O. Thus, we comprehensively summarize the latest types of rare earth-containing catalysts used in the traditional NH3-SCR process and low-temperature NH3-SCR system. Also, the reaction mechanisms of rare earth-containing catalysts are compared and discussed. Finally, the general development of rare earth in NH3-SCR catalysts is proposed.