Poisoning Effect Comparison of ZnCl <sub>2</sub> and ZnSO <sub>4</sub> on Mn‐Ce/AC Catalyst for Low‐Temperature SCR of NO
Zenghui Su, Shan Ren, Jie Yang, Lu Yao, Yuhan Zhou, Zhichao Chen, Tianshi Zhang
Abstract
Abstract In this study, the effect of different zinc salts (ZnCl 2 and ZnSO 4 ) on the deactivation of activated carbon(AC)‐based Mn−Ce catalysts and the poisoning mechanism of zinc salts on Mn−Ce/AC are comparatively studied. SEM, BET, XRD, XPS, H 2 ‐TPR, NH 3 ‐TPD and In‐situ DRIFT are used to characterize the physical and chemical changes of Mn−Ce/AC catalyst. The Selective Catalytic Reduction (SCR) activities of Mn−Ce/AC has a noticeable decline after loading zinc salts, and the highest NO conversion of Zn poisoning catalysts do not exceed 70 %. And the acid site is occupied by Zn 2+ on the catalyst, which affects the chemical adsorption of NH 3 and hinders the formation of the intermediate ‐NH 2 . Moreover, the decrease of Mn 4+ , reducibility of manganese oxide and acid sites are more serious on ZnC−Mn‐Ce/AC. Besides, loading ZnSO 4 can improve the content of Ce 3+ and O β on catalyst surface, which can mitigate the poisoning effects of ZnSO 4 on Mn−Ce/AC catalyst. Hence, ZnCl 2 displays a more serious poisoning effect on Mn−Ce/AC catalyst compared with ZnSO 4 . Then the probable mechanism model of ZnCl 2 and ZnSO 4 on Mn−Ce /AC catalyst is proposed and compared.