Abstract
The character of coke is typically regarded as a “deactivator” in zeolite catalysis. We report the interdependence of coke nature and location with its true character in the mechanisms of ethylene oligomerization: a model zeolite catalyzed transformation involved in many sustainable processes. We prepared, characterized, and tested ZSM-5 zeolites of different diffusion paths and acidities, using polymeric-, organic-template, or template-free strategies and various Si/Al ratios. The results indicate that coke can improve the selectivity/yield of higher olefins and jet-fuel aliphatics, and this positive effect is better than modifying the number of acid sites. The molecular-level nature of these coke species is elucidated using high-resolution mass spectrometry. The “enhancer” character of the coke can be better exploited in polymeric templated (hierarchical) ZSM-5 zeolite because mesopores retain coke without critically affecting accessibility or causing deactivation. Furthermore, this catalyst is stable for at least 74 h on stream and in multiple reaction-regeneration cycles.
Original language | English (US) |
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Article number | 121582 |
Journal | Applied Catalysis B: Environmental |
Volume | 316 |
DOIs | |
State | Published - Nov 5 2022 |
Bibliographical note
Funding Information:This work was supported by the King Abdullah University of Science and Technology (KAUST).
Publisher Copyright:
© 2022 Elsevier B.V.
Keywords
- alkene
- catalyst deactivation
- ethene oligomerization
- hierarchical zeolite
- MFI structure
ASJC Scopus subject areas
- Catalysis
- General Environmental Science
- Process Chemistry and Technology