Nature of active sites and deactivation mechanism for n-butane isomerization over alumina-promoted sulfated zirconia
| Autor: | Jiaoyu Zhang, Pengzhao Wang, Chaohe Yang, Chunyi Li, Guowei Wang |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Inorganic chemistry
Butane 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Photochemistry 01 natural sciences Butene Catalysis 0104 chemical sciences chemistry.chemical_compound Sulfation chemistry Sulfite Dehydrogenation Physical and Theoretical Chemistry Sulfate 0210 nano-technology Isomerization |
| Zdroj: | Journal of Catalysis. 338:124-134 |
| ISSN: | 0021-9517 |
| DOI: | 10.1016/j.jcat.2016.02.027 |
| Popis: | The deactivation of n-butane isomerization on alumina-promoted sulfated zirconia (SZA) was studied at 473 K under atmospheric pressure. Under N2, the regeneration temperature influences the isomerization activity greatly. The change of the sulfate species during the deactivation process was determined quantitatively by a temperature-programmed evolution mass spectrometer. Two active sites, reducible sites and acid sites, exist on the catalyst surface and show a synergistic effect on the n-butane isomerization reaction. The reducible sulfate species play an important role in butene formation via oxidative dehydrogenation of n-butane, while the acid sites are responsible for the isomerization steps. The reduction of sulfate species and the accumulation of sulfite species on the surface, which cause the decrease of butene concentration in the catalyst bed, are the main reasons for catalyst deactivation. Based on these findings, a new reaction model and two possible ways to improve the catalytic stability of SZA catalyst are proposed. |
| Databáze: | OpenAIRE |
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