Release Time:2019-03-10  Hits:

Indexed by: Journal Article

Date of Publication: 2008-07-01

Journal: CATALYSIS LETTERS

Included Journals: EI、SCIE

Volume: 123

Issue: 3-4

Page Number: 289-293

ISSN: 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.