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Indexed by:期刊论文

Date of Publication:2008-07-01

Journal:CATALYSIS LETTERS

Included Journals:SCIE、EI

Volume:123

Issue:3-4

Page Number:289-293

ISSN No.:1011-372X

Key Words:nitric oxide; nitrate; rate-determining step; promotional effect; selective catalytic reduction of NO

Abstract:Nitrate species is crucial intermediate of selective catalytic reduction of NO by acetylene (C(2)H(2)-SCR) over HZSM-5. It is proposed that formation of nitrate species on the zeolite is rate-determining step of C(2)H(2)-SCR. The proposition is supported by the experimental results: (1) No nitrate species could be detected by in situ FTIR in steady C(2)H(2)-SCR over HZSM-5 at 350 degrees C, while the bands due to nitrate species were clearly observed on the zeolite both in situ in NO + O(2) and after a brief evacuation at the temperature; (2) Yttrium incorporation into HZSM-5 zeolite considerably enhanced nitrate species formation on the catalyst and correspondingly the activity of the catalyst for C(2)H(2)-SCR was significantly increased. Both the promotional effect of yttrium on C(2)H(2)-SCR and the rate-determining step of C(2)H(2)-SCR being nitrate species formation over the catalyst were first reported herein.