1. The deactivation effect of Na2O and NaCl on CeO2–TiO2 catalysts for selective catalytic reduction of NO with NH3.
- Author
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Jiang, Ye, Shi, Weiyun, Lai, Chengzhen, Gao, Wenqian, Yang, Lin, Yu, Xianxian, Yang, Zhengda, and Lin, Riyi
- Subjects
CATALYTIC reduction ,SELECTIVE catalytic oxidation ,CATALYSTS ,BRONSTED acids ,CATALYTIC activity ,SURFACE area ,CERIUM oxides - Abstract
The effect of Na 2 O and NaCl on CeO 2 –TiO 2 catalyst for the selective catalytic reduction of NO with NH 3 was investigated with BET, XRD, XPS, NH 3 -TPD, H 2 -TPR, in-situ DRIFT and catalytic activity measurements. The results showed that both Na species could deactivate the CeO 2 –TiO 2 catalyst and Na 2 O had a stronger effect than NaCl. The more serious deactivation by Na 2 O could be ascribed to smaller surface area, fewer surface Ce
3+ and chemical adsorbed oxygen, lower surface acidity, and worse reducibility. The introduction of NaCl and Na 2 O facilitated the formation of new surface NO x adspecies, but were inactive in NH 3 -SCR reaction. The adsorption of NH 3 were inhibited. The NH 3 -SCR reaction over the CeO 2 –TiO 2 catalyst was governed by both E-R and L-H mechanisms. The introduction of NaCl and Na 2 O didn't change the NH 3 -SCR reaction mechanisms. • The poisoning effect of Na 2 O is more serious than NaCl over CeO 2 –TiO 2 catalyst. • The loss of more acid sites (especially Brønsted acid sites) over Na 2 O0.5 -CT catalyst than NaCl0.5 -CT. • Na 2 O inhibits NH 3 adsorption on CeO 2 –TiO 2 catalyst more significantly than NaCl. • Na species could supply some active sites to absorb NO x species which were inactive in NH 3 -SCR reaction. • The introduction of NaCl and Na 2 O don't change the NH 3 -SCR reactions mechanisms. [ABSTRACT FROM AUTHOR]- Published
- 2020
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