Effects of Hydrothermal Aging on NH3-SCR reaction over Cu/zeolites
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 NO{sub x} by NH{sub 3}. After hydrothermal aging at 800 C for 16 h, the NO{sub x} reduction performance of Cu-ZSM-5 and Cu-beta were 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 {sup 27}Al-NMR, significant reduction in the intensities of the tetrahedral aluminum peak was observed for Cu-ZSM-5 and Cu-beta, although no increase in the intensities of the octahedral aluminum peak was observed. When the redox behavior of Cu species was examined using H{sub 2}-TPR, it was found that Cu{sup 2+} could be reduced to Cu{sup +} and to Cu{sup 0} fir Cu-ZSM-5 and Cu-beta catalysts, while Cu{sup 2+} could be reduced to Cu{sup +} only for 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.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 1034968
- Report Number(s):
- PNNL-SA-81754; JCTLA5; 35404; VT0401000; TRN: US201204%%261
- Journal Information:
- Journal of Catalysis, Vol. 287, Issue 1; ISSN 0021-9517
- Country of Publication:
- United States
- Language:
- English
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