Fe-Containing Zeolites for NH 3 -SCR of NO x : Effect of Structure, Synthesis Procedure, and Chemical Composition on Catalytic Performance and Stability.

Autor: Martín N; Instituto de Tecnología Química, Universitat Politècnica de València, Consejo Superior de Investigaciones Científicas, Avenida de los Naranjos s/n, 46022, València, Spain., Vennestrøm PNR; Haldor Topsøe A/S, Haldor Topsøes Allé 1, 2800, Lyngby, Denmark., Thøgersen JR; Haldor Topsøe A/S, Haldor Topsøes Allé 1, 2800, Lyngby, Denmark., Moliner M; Instituto de Tecnología Química, Universitat Politècnica de València, Consejo Superior de Investigaciones Científicas, Avenida de los Naranjos s/n, 46022, València, Spain., Corma A; Instituto de Tecnología Química, Universitat Politècnica de València, Consejo Superior de Investigaciones Científicas, Avenida de los Naranjos s/n, 46022, València, Spain.
Jazyk: angličtina
Zdroj: Chemistry (Weinheim an der Bergstrasse, Germany) [Chemistry] 2017 Sep 27; Vol. 23 (54), pp. 13404-13414. Date of Electronic Publication: 2017 Aug 29.
DOI: 10.1002/chem.201701742
Abstrakt: The direct preparation of different iron-containing Beta and CHA zeolites has been attempted under diverse synthesis conditions, including in alkaline and fluoride media, to evaluate the influence of their physicochemical properties on the selective catalytic reduction (SCR) of NO x using NH 3 as reductant. Of the different Fe-Beta zeolites, the sample prepared in the absence of alkali cations with a Si/Al ratio of around 13 showed high NO conversion values (>90 %). However, this catalyst suffered from severe deactivation when aged at high temperatures in the presence of steam. The preparation of more hydrophobic Fe-Beta zeolites did not improve the resistance of the catalyst against steam. In contrast, Fe-CHA zeolites prepared by a one-pot method under alkaline conditions with a Si/Al ratio of around 13 by using N,N,N-trimethyladamantylammonium as template not only showed excellent catalytic activity but also high hydrothermal stability, especially when sodium cations were selectively removed. Moreover, the Fe-CHA material synthesized by using the less expensive tetraethylammonium template also resulted in an active and hydrothermally stable catalyst.
(© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)
Databáze: MEDLINE
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