Poisoning Effect Comparison of ZnCl₂ and ZnSO₄ on Mn‐Ce/AC Catalyst for Low‐Temperature SCR of NO

Abstract

In this study, the effect of different zinc salts (ZnCl 2 and ZnSO 4 ) on the deactivation of activated carbon(AC)-based MnÀ Ce catalysts and the poisoning mechanism of zinc salts on MnÀ 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 MnÀ Ce/AC catalyst. The Selective Catalytic Reduction (SCR) activities of MnÀ 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 ZnCÀ 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 MnÀ Ce/AC catalyst. Hence, ZnCl 2 displays a more serious poisoning effect on MnÀ Ce/AC catalyst compared with ZnSO 4 . Then the probable mechanism model of ZnCl 2 and ZnSO 4 on MnÀ Ce /AC catalyst is proposed and compared.

How Does Zinc Species Affect the Performance of CeO2–TiO2 Catalysts for Selective Catalytic Reduction of NO with NH3? A Comparative Laboratory Experiment

“…Loading Zn species resulted in varying reductions in the Ce 3+ percentage, with the most significant decrease observed in the ZnCl 2 -poisoned catalyst, aligning with the NO conversion (Figure ). Importantly, the ZnSO 4 -poisoned catalyst exhibited the smallest decline, possibly due to the promotion of Ce 3+ formation by SO 4 2– , consistent with the results of Su et al, who researched the effect of ZnSO 4 on the SCR performance of Mn–Ce/AC catalysts.…”

“…, consistent with the results of Su et al, 26 who researched the effect of ZnSO 4 on the SCR performance of Mn−Ce/AC catalysts.…”

“…Furthermore, as the Zn loading increases, the average grain sizes gradually decrease. The parallel phenomena can be found in the investigation conducted by Su et al and Liu et al., , who examined the impact of ZnCl 2 and ZnSO 4 species on the Mn–Ce/AC and Mn/TiO 2 SCR catalysts’ activity.…”

Effect of Different Zinc Species on Mn-Ce/CuX Catalyst for Low-Temperature NH3-SCR Reaction: Comparison of ZnCl2, Zn(NO3)2, ZnSO4 and ZnCO3

“…The deactivation rate of various poisonous zinc species was shown to be in the order of ZnCl 2 > ZnSO 4 > ZnO by Wang et al [15], who studied the effects of three distinct zinc species (ZnO, ZnSO 4 , and ZnCl 2 ) on Sb-CeZr 2 O x catalysts. According to our earlier research [16,17], ZnCl 2 had a more severe poisoning effect on the Mn-Ce/AC catalyst than ZnSO 4 , and Zn 2+ would occupy the acidic site of the catalyst after loading zinc salts. Nonetheless, the poisoning impact of various zinc species on Cu-exchanged zeolite catalysts has received insufficient attention till now.…”

Selective Oxidation of Triethylamine Catalyzed by Mn-Ce/ZSM-5

“…Manganese oxide is considered a kind of active low-cost catalyst, but its strong oxidation will lead to excessive production of NO x in the oxidation process of NVOCs. ,− The production of more Mn 4+ species is facilitated by CeO x . The inclusion of CeO x increases the nitrogen selectivity in oxidation events where Mn 4+ species serve as the catalytic active site. − In this paper, an impregnation approach was used to manufacture a series of catalysts with varied Mn/Ce ratios loaded on ZSM-5, and the catalytic activity for the selective oxidation of TEA was tested.…”