| Autor: |
Goguet, A., Burch, R., Chen, Y., Hardacre, C., Hu, P., W. Joyner, R., C. Meunier, F., S. Mun, B., Thompsett, D., Tibiletti, D. |
| Zdroj: |
The Journal of Physical Chemistry - Part C; November 2007, Vol. 111 Issue: 45 p16927-16933, 7p |
| Abstrakt: |
On-stream deactivation during a water gas shift (WGS) reaction over gold supported on a ceria−zirconia catalyst was examined. Although the fresh catalyst has very high low temperature (<200 °C) for WGS activity, a significant loss of CO conversion is found under steady-state operations over hours. This has been shown to be directly related to the concentration of water in the gas phase. The same catalyst also undergoes thermal deactivation above 250 °C, and using a combined experimental and theoretical approach, a common deactivation mechanism is proposed. In both cases, the gold nanoparticles, which are found under reaction conditions, are thought to detach from the oxide support either through hydrolysis, <250 °C, or thermally, >250 °C. This process reduces the metal−support interaction, which is considered to be critical in determining the high activity of the catalyst. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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