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[Untitled]

Authors :
Blanka Wichterlová
Dalibor Kaucký
Jiří Dědeček
Source :
Topics in Catalysis. 18:283-290
Publication Year :
2002
Publisher :
Springer Science and Business Media LLC, 2002.

Abstract

Selective catalytic reduction of NO with methane (CH4-SCR) in an excess of oxygen over Co ions located in ZSM-5 of various Si/Al composition and in ferrierite, mordenite, chabazite and beta zeolite was investigated. From the comparison of the dependence of the TOF values per Co ion for NO conversion to N2 and Co ions distribution among the cationic sites on total Co ion concentration, the catalytic activity of the individual Co ions was estimated. The α-type Co2+ ions, located in the main channel of mordenite and ferrierite and coordinated above the rectangle of four framework oxygens of the channel wall exhibit the highest activity in these zeolites. On the other hand, the β-type Co2+ ions coordinated in the plane of four oxygens of the deformed six-member ring located in the channel intersection of ZSM-5 and in channels of beta zeolite control the activity of these Co zeolites. The sequence of activity of Co2+ ions in CH4-SCR of NO was FER Coα>ZSM-5 Coβ>BEA Coβ≈ZSM-5 Coα≫FER Coβ≈MOR Coα≫CHA Co≈MOR Coβ. A correlation between the activity of the individual Co ions in CH4-SCR of NO and a distance between the cationic sites was observed.

Details

ISSN :
10225528
Volume :
18
Database :
OpenAIRE
Journal :
Topics in Catalysis
Accession number :
edsair.doi...........91b80b1acef0961412df6421c95cbeff
Full Text :
https://doi.org/10.1023/a:1013855125603