| Autor: |
Roderick W. Sidwell, Brian A Kibler, Robert J. Kee, David T. Wickham, Huayang Zhu |
| Rok vydání: |
2003 |
| Předmět: |
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| Zdroj: |
Applied Catalysis A: General. 255:279-288 |
| ISSN: |
0926-860X |
| DOI: |
10.1016/s0926-860x(03)00566-0 |
| Popis: |
This paper reports a quantitative comparison between two metal-substituted hexaaluminate catalysts and supported Pd catalyst (3 wt.% Pd/γ-Al 2 O 3 ). Measured species profiles in stagnation-flow boundary layers are used to infer reaction rates by heterogeneous catalysis. The Pd-substituted material (Sr 0.5 Pd 0.5 Al 11 O 18− α ) is suitable for low-temperature operation and the La x Sr y Mn 0.4 Al 11 O 18− α ( x / y =0.8, 0.9, and 1.1) material is a good high-temperature catalyst. A wide range of operating temperatures and methane-air equivalence ratios are considered. The La x Sr y Mn 0.4 Al 11 O 18− α catalysts show good catalytic activity at temperatures up to 1100 ° C and are insensitive to La/Sr ratio and coating thickness. The supported-Pd catalyst and the Sr 0.5 Pd 0.5 Al 11 O 18− α exhibit similar hysteresis characteristics when exposed to temperatures around 900 ° C. The supported Pd deactivates upon exposure to temperatures above 900 ° C, but the Pd-substituted hexaaluminate maintains good catalytic activity after high-temperature exposure. The supported Pd is generally more active than either hexaaluminate, but can suffer permanent deactivation upon high temperature exposure. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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