Changes in Cu2+ environment upon wet deactivation of Cu-ZSM-5 deNOx catalysts

被引：56

作者：

Gómez, SA

Campero, A

Martínez-Hernández, A

Fuentes, GA

机构：

[1] Univ Autonoma Metropolitana Iztapalapa, Area Ingn Quim, Mexico City 09340, DF, Mexico

[2] Univ Autonoma Metropolitana Iztapalapa, Area Quim Inorgan, Mexico City 09340, DF, Mexico

来源：

APPLIED CATALYSIS A-GENERAL | 2000年 / 197卷 / 01期

关键词：

Cu-ZSM-5; NOx reduction; EPR; deactivation selective catalytic reduction; hydrothermal treatment; effect of water;

D O I：

10.1016/S0926-860X(99)00546-3

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Through measurement of Cu2+ species via electron paramagnetic resonance (EPR) we detected changes in the distribution of Cun+ sites in Cu-ZSM-5 samples used in the selective catalytic reduction of NO with C3H8 in the presence of H2O at 673 K. In samples used under dry or wet operation for short periods of time, Cu2+ species were evenly distributed between square planar and square pyramidal environments. Operation under wet conditions for periods of the order of tens of hours caused a third Cu2+ species to be formed, presumably located in a recessed location in the zeolite. At the same time, irreversible deactivation was manifest, suggesting an association between those events. Neither structural changes nor dealumination of the zeolite were detected in our studies, indicating that deactivation was caused only by changes in the distribution of Cun+ sites. (C) 2000 Elsevier Science B.V. All rights reserved.

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页码：157 / 164

页数：8

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