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Insights into the Inhibitory Effect of H 2 O on Hg‐Catalytic Oxidation over the MnO x ‐Based Catalysts
Author(s) -
Zhou Zijian,
Leng Erwei,
Li Chengpu,
Zhu Xinbo,
Zhao Bo
Publication year - 2019
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201900175
Subject(s) - catalysis , adsorption , chemistry , flue gas , chlorine , inorganic chemistry , oxygen , water vapor , mercury (programming language) , chlorine gas , nuclear chemistry , organic chemistry , computer science , programming language
MnO x ‐based catalyst has been used for elemental mercury (Hg 0 ) removal in the coal‐fired flue gas, but the H 2 O in the flue gas significantly inhibits its activity. Generally, it is believed the inhibitory effect is caused by competitive adsorption between Hg 0 /HCl and H 2 O. In this study, we found that the MnO x was also aged in the flue gas with high concentration of H 2 O. The results indicated that the catalysts would be aged by H 2 O. The characterization of the fresh and aged catalysts showed that the amount of Mn 4+ and chemisorbed oxygen species decreased. H 2 O didn't inhibit HCl adsorption on the catalyst surface, but suppressed the formation of active chlorine species, which was active for Hg 0 removal. Therefore, besides the generally known competitive adsorption mechanism, there should be other possible reasons to interpret the inhibitory effects of water vapor on Hg 0 oxidation process.