Comparison study of Na poisoning effect on copper-based chabazite micropore catalysts for NH3-SCR reaction

被引：0

作者：

Wang C. ^{[1
,2
]}

Chen Z. ^{[1
]}

Wang J. ^{[1
]}

Shen M. ^{[1
,3
]}

Wang J. ^{[1
]}

机构：

[1] School of Chemical Engineering and Technology, Tianjin University, Tianjin

[2] School of Environmental and Safety Engineering, North University of China, Taiyuan

[3] State Key Laboratory of Engines, Tianjin University, Tianjin

来源：

Huagong Xuebao/CIESC Journal | 2020年 / 71卷 / 12期

关键词：

Alkali metal; Catalysts; Nitric oxide; Poison mechanism; Selective catalytic reduction; Zeolite;

D O I：

10.11949/0438-1157.20200408

中图分类号：

学科分类号：

摘要：

Using wet impregnation method to mimic alkali metal poison of ammonia-selective catalytic reduction (NH3-SCR) catalysts, Cu-based micropore zeolites Cu/SSZ-13 and Cu/SAPO-34 with different Na contents(mass fraction) were prepared, and the Na poisoning mechanism on them was studied. The results show that the externally introduced Na ions can severely affect the NH3-SCR catalytic activity of the two catalysts, resulting in the collapse of the crystal structure of the catalyst, the decrease of acidity and the reduction of active species. In detail, when Na content was less than 1.82%, Cu/SAPO-34 has higher resistance of Na ions than Cu/SZZ-13; while when Na> 3.48%, Cu/SAPO-34 catalysts almost deactivated thoroughly. By structural characterization (BET, XRD and SEM) and acidity characterization (DRIFTS, NH3-TPD and H2-TPR), it was found that with Na poisoning deeper and deeper, Cu/SSZ-13 took a gradual style of the structural destruction, but Cu/SAPO-34 adopted a sudden way. Studies on the mechanism of Na poisoning show that the decrease of acid sites is the main reason for the decrease of SCR activity of Cu/SSZ-13, and the structural collapse is the main reason for the decrease of SCR activity of Cu/SAPO-34. © 2020, Editorial Board of CIESC Journal. All right reserved.

引用

页码：5551 / 5560

页数：9

共 36 条

[1] Yang G., The first car in the world: Benz patent motor, Auto Time, 12, pp. 92-93, (2013)
[2] Li Y Y., Research on total amount of vehicular emission in Beijing-Tianjin-Hebei (BTH) region and its abatement control strategy, (2015)
[3] Wang X X., Study on prediction and control measures of motor vehicle pollutant emission, (2012)
[4] Li Y H., Motor vehicle pollution and its prevention and control countermeasures, Environmental Science and Technology, 2, pp. 37-38, (2000)
[5] China Mobile Source Environmental Management Annual Report(2019), (2019)
[6] Busca G, Lietti L, Ramis G, Et al., Chemical and mechanistic aspects of the selective catalytic reduction of NOx by ammonia over oxide catalysts: a review, Applied Catalysis B: Environmental, 18, 1, pp. 1-36, (1998)
[7] Su L, Zhou L B, Jiang D M, Et al., Recent development of aftertreatment of diesel emissions, Internal Combustion Engines, 1, pp. 1-8, (2003)
[8] Forzatti P, Lietti L, Nova I, Et al., Diesel NOx aftertreatment catalytic technologies: analogies in LNT and SCR catalytic chemistry, Catalysis Today, 151, 3, pp. 202-211, (2010)
[9] Girard J, Cavataio G, Snow R, Et al., Combined Fe-Cu SCR systems with optimized ammonia to NOx ratio for diesel NOx control, SAE International Journal of Fuels and Lubricants, 1, 1, pp. 603-610, (2009)
[10] Arous W, Tounsi H, Djemel S, Et al., Selective catalytic reduction of nitric oxide with ammonia on copper (Ⅱ) ion-exchanged offretite, Catalysis Communications, 6, 4, pp. 281-285, (2005)

← 1 2 3 4 →