Journal
ENVIRONMENTAL SCIENCE & TECHNOLOGY
Volume 50, Issue 17, Pages 9576-9582Publisher
AMER CHEMICAL SOC
DOI: 10.1021/acs.est.6b02307
Keywords
-
Categories
Funding
- National Natural Science Foundation of China [21407088]
- National Science Fund for Distinguished Young Scholars [21325731]
- International Postdoctoral Exchange Fellowship Program of China [20130032, 20160063]
- Brook Byers Institute for Sustainable Systems (BBISS)
- Hightower Chair and Georgia Research Alliance at Georgia Institute of Technology
Ask authors/readers for more resources
The in situ IR and Raman spectroscopy measurements were conducted to investigate lead poisoning on the CeO2-WO3 catalysts. The deactivation mechanisms were studied with respect to the changes of surface acidity, redox property, nitrate/nitrite adsorption behaviors, and key active sites (note that the results of structure activity relationship of CeO2-WO3 were based on our previous research). (1) Lewis acid sites originated from CeO2 and crystalline WO3, whereas Bronsted acid sites originated from Ce-2(WO4)(3). The poisoned catalysts exhibited a lower surface acidity than the fresh catalysts: the number of acid sites decreased, and their thermal stability weakened. (2) The reducibility of catalysts and the amount of active oxygen exhibited a smaller influence after poisoning because lead preferred to bond with surface WOx species rather than CeO2. (3) The quantity of active nitrate species decreased due to the lead coverage on the catalyst and the partial bridged-nitrate species induced by lead exhibited a low degree of activity at 200 degrees C. (4) Crystalline WO3 and Ce-2(WO4)(3) originated from the transformation of polytungstate sites. These sites were the key active sites during the SCR process. The formation temperatures of polytungstate on the poisoned catalysts were higher than those on the fresh 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