Journal
CHEMICAL ENGINEERING JOURNAL
Volume 389, Issue -, Pages -Publisher
ELSEVIER SCIENCE SA
DOI: 10.1016/j.cej.2020.124271
Keywords
NH3-SCR; Ammonium bisulfate; Metal sulfate; Fe2O3-WO3 catalyst; Sulfur-resistant
Categories
Funding
- National Natural Science Foundation of China [21773106, 21707066, 21806077, 21976081]
- Major Scientific and Technological Project of Bingtuan [2018AA002]
- Environmental Protection Department of Jiangsu Province [2016048]
Ask authors/readers for more resources
Ammonium bisulfate (ABS) has long been considered as a main poisoning material in the selective catalytic reduction by NH3 (NH3-SCR) due to the inevitable coverage of sticky ABS on catalytic active sites in sulfur-containing atmospheres, which severely hinders the achievement of stable and highly active NH3-SCR catalysts. In the present study, we report a novel observation of the dual effects of ABS on the NH3-SCR reaction. That is, ABS inhibits the NH3-SCR performance of Fe2O3-WO3/MCM-41 catalyst at low temperatures (50-200 degrees C) but shows apparent and sustainable reaction promotion when the temperature surpasses 250 degrees C. X-ray photoelectron spectroscopy (XPS) and NO probing adsorption confirmed that when ABS is deposited on the catalyst surface, a partial interaction between ABS and the Fe2O3-WO3 component occurs, resulting in blocking of the active sites and an obvious loss of catalytic activity. With increasing reaction temperature, the ammonium in ABS can be facilely consumed by NO/O-2, thus inducing the disintegration of poisoning species. The sulfate group transforms into metal sulfate and survives at high temperatures. Importantly, owing to the strong inductive effect of sulfate species, both the acidity and redox properties of the catalyst are greatly improved, which contributes to the enhanced activity. The results of the present study expand our knowledge of the role of ABS in the NH3-SCR reaction and will be useful for designing high-performing NH3-SCR catalysts.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available