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Indexed by:期刊论文

Date of Publication:2014-12-01

Journal:MICROPOROUS AND MESOPOROUS MATERIALS

Included Journals:SCIE、Scopus

Volume:200

Page Number:304-310

ISSN No.:1387-1811

Key Words:Organotemplate-free Beta zeolite; Cu-Beta catalyst; NH3-SCR; H-2-TPR; CO-FTIR

Abstract:A series of Cu-exchanged Al-rich Beta zeolites from organotemplate-free synthesis was prepared and investigated for selective catalytic reduction (SCR) of NOx with NH3 in exhaust gas streams. In comparison to conventional Cu-Beta zeolite with Si/Al ratio of 19, Cu-Beta zeolite with Si/Al ratio of 4 is a superior low-temperature NH3-SCR catalyst. Very high NO conversion (>95%) can be achieved at temperatures as low as 150 to similar to 400 degrees C. XRD, UV-Vis-NIR and NH3-TPD measurements show that more isolated Cu2+ ions are present at the exchange sites of Al-rich Beta zeolite. The combination of CO-FTIR and H-2-TPR analysis demonstrates that Cu2+ ions could be reduced more readily on the Al-rich Beta than on the conventional Beta probably due to the proximity of the isolated Cu2+ ions. These can be correlated to the enhancement of NO conversion at lower temperatures over Cu-exchanged Al-rich Beta zeolite. (C) 2014 Elsevier Inc. All rights reserved.