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(Reference retrieved automatically from SciELO through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Selective catalytic reduction of NO to N2 with copper and cobalt exchanged ZSM-5 zeolites: the effect of calcium addition

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Author(s):
Leandro Martins [1] ; Robson Pablo S. Peguin [2] ; Martin Wallau [3] ; Ernesto Antonio Urquieta-González [4]
Total Authors: 4
Affiliation:
[1] Universidade Federal de São Carlos. Departamento de Engenharia Química - Brasil
[2] Universidade Federal de São Carlos. Departamento de Engenharia Química - Brasil
[3] Universidade Federal de São Carlos. Departamento de Engenharia Química - Brasil
[4] Universidade Federal de São Carlos. Departamento de Engenharia Química - Brasil
Total Affiliations: 4
Document type: Journal article
Source: Journal of the Brazilian Chemical Society; v. 16, p. 589-596, 2005-06-00.
Abstract

ZSM-5 catalysts containing either Cu or Co cations individually or Cu/Ca or Co/Ca cation combinations were prepared by ion exchange. These materials were tested as catalysts for the reduction of NO to N2 in the presence of propane or methane. Cu2+ and [Cu-O-Cu]2+ species were identified in ion exchangeable sites in the copper-containing catalysts. The amount of the latter cation increased with increasing copper content and in the presence of Ca2+ and was the most active in the reduction of NO. However, at temperatures higher than 400 ºC its activity decreased markedly. For cobalt-exchanged zeolites, Co2+ in charge-compensation sites or Co3+ in extra-framework precipitates were present in the catalysts. It was verified that the amount of Co3+ diminished with the presence of Ca2+. For the catalysts prepared in this study no significant differences in specific activity for the reduction of NO or for methane oxidation were observed in the presence of calcium. (AU)