US EPA

1552851 

Journal Article 

Effects of hydrothermal aging on NH3-SCR reaction over Cu/zeolites 

Kwak, J; Tran, D; Burton, SD; Szanyi, J; Lee, JH; Peden, CHF 

2012 

Yes 

Journal of Catalysis
ISSN: 0021-9517
EISSN: 1090-2694 

287 

203-209 

10.1016/j.jcat.2011.12.025 

WOS:000302046200022 

The effects of hydrothermal treatment on model Cu/zeolite
catalysts were investigated to better understand the nature of Cu species for the selective
catalytic reduction of NOx by NH3. After hydrothermal aging at 800 degrees C for 16 h, the NOx
reduction performance of Cu-ZSM-5 and Cu-beta was significantly reduced at low temperatures,
while that of Cu-SSZ-13 was not affected. When the zeolite framework aluminum species were probed
using solid state Al-27 MASNMR, significant reduction in the intensities of the tetrahedral
aluminum peak intensity was observed for Cu-ZSM-5 and Cu-beta, although no increase in the
intensities of the octahedral aluminum peak was detected. When the redox behavior of Cu species
was examined using H-2-TPR, it was found that Cu2+ could be reduced to Cu. and to Cu-0 for Cu-
ZSM-5 and Cu-beta catalysts, while Cu2+ could be reduced only to Cu2+ in Cu-SSZ-13. After
hydrothermal aging, CuO and Cu-aluminate species were found to form in Cu-ZSM-5 and Cu-beta,
while little changes were observed for Cu-SSZ-13. (C) 2012 Elsevier Inc. All rights reserved. 

Cu-SSZ-13; NH3-SCR; Hydrothermal aging; H-2-TPR; Solid state Al-27 NMR