DRIFT Studies on the Selectivity Promotion Mechanism of Ca-Modified Ce-Mn/TiO2 Catalysts for Low-Temperature NO Reduction with NH3

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• 作者：Yue Liu ; Tingting Gu ; Xiaole Weng ; Yan Wang ; Zhongbiao Wu ; Haiqiang Wang
• 刊名：The Journal of Physical Chemistry C
• 出版年：2012
• 出版时间：August 9, 2012
• 年：2012
• 卷：116
• 期：31
• 页码：16582-16592
• 全文大小：534K
• 年卷期：v.116,no.31(August 9, 2012)
• ISSN：1932-7455

文摘

Manganese-based catalysts have shown excellent low-temperature selective catalytic reduction (SCR) activity for NO_x removal. However, they would always produce a high amount of more toxic byproduct, N₂O. Ca modification has been reported to be able to promote N₂ selectivity for SCR catalysts, but the mechanism is still not clear. In this study, a series of Ca-modified Ce_0.02Mn_0.4/TiO₂ SCR catalysts were utilized for mechanism study. In terms of DRIFT analysis, the addition of Ca had significantly reduced the formation of NH on catalyst surface, which limited its reaction with NO to form N₂O. Furthermore, Ca addition had also caused a deceased formation of NO₂, reducing its reaction with NH₃ to form N₂O, further increasing the N₂ selectivity of the catalysts. The results present herein could be beneficial to the development of efficient low-temperature SCR catalysts, particularly for Mn-based SCR catalysts.