化工进展2017，Vol.36Issue(11)：4064-4071,8.DOI:10.16085/j.issn.1000-6613.2017-0264
铁铈复合选择性催化还原脱硝催化剂的碱金属(钾)中毒机理
Alkali metal(potassium)poisoning mechanism of CeFeOx catalysts for selective catalytic reduction of NOx
摘要
Abstract
Alkali metals(potassium & sodium)were loaded on the iron-cerium composite catalysts (FeCeOx) using wet impregnation method to simulate the poisoning phenomenon,while the FeCeOx catalysts were synthesized by citric acid method. The effect of the alkali metals on the catalytic performance of CeFeOx for the low temperature selective catalytic reduction (SCR) of NOx with NH3 was investigated. To analyze the deactivation reasons and mechanism,the catalysts were characterized by N2 adsorption,temperature programmed desorption(NH3-TPD,NO-TPD),H2 temperature programmed reduction(H2-TPR)and in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS)techniques. It is found that the poisoning effect of K is stronger than that of Na on this kind of catalyst. The addition of potassium reduces the specific surface area as well as the redox properties of the catalyst. NOx adsorption of the catalyst is further influenced at low temperature. Particularly, active nitrate species decrease with the increase of inactive nitrate species. The main factor of deactivation may be the significant decline in surface acidity, including both Br?nsted acid and Lewis acid, which hinders NH3 adsorption over CeFeOx.关键词
低温选择性催化还原/碱金属中毒/铁铈复合催化剂/失活/表征Key words
low temperature SCR/alkali metal poisoning/FeCeOx catalysts/deactivation/characterization分类
资源环境引用本文复制引用
王丽霞,仲兆平,朱林,杨瀚..铁铈复合选择性催化还原脱硝催化剂的碱金属(钾)中毒机理[J].化工进展,2017,36(11):4064-4071,8.基金项目
江苏省政策引导类计划(产学研合作)项目(BY2015070-21). （产学研合作）
