Reversible nature of coke formation on Mo/ZSM-5 methane dehydroaromatization catalysts
| Autor: | Emiel J. M. Hensen, Lingqian Meng, Alexander Parastaev, Yujie Liu, Nikolay Kosinov, Evgeny A. Uslamin |
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| Přispěvatelé: | Inorganic Materials & Catalysis |
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Materials science
zeolites operando spectroscopy 010402 general chemistry Heterogeneous catalysis 01 natural sciences Chemical reaction Catalysis Methane chemistry.chemical_compound Operando spectroscopy Zeolite 010405 organic chemistry Communication methane dehydroaromatization General Chemistry Coke General Medicine Communications 0104 chemical sciences heterogeneous catalysis Chemical engineering chemistry ZSM-5 deactivation |
| Zdroj: | Angewandte Chemie-International Edition, 58(21), 7068-7072. Wiley Angewandte Chemie (International Ed. in English) |
| ISSN: | 1521-3773 1433-7851 |
| Popis: | Non-oxidative dehydroaromatization of methane over Mo/ZSM-5 zeolite catalysts is a promising reaction for the direct conversion of abundant natural gas into liquid aromatics. Rapid coking deactivation hinders the practical implementation of this technology. Herein, we show that catalyst productivity can be improved by nearly an order of magnitude by raising the reaction pressure to 15 bar. The beneficial effect of pressure was found for different Mo/ZSM-5 catalysts and a wide range of reaction temperatures and space velocities. High-pressure operando X-ray absorption spectroscopy demonstrated that the structure of the active Mo-phase was not affected by operation at elevated pressure. Isotope labeling experiments, supported by mass-spectrometry and 13 C nuclear magnetic resonance spectroscopy, indicated the reversible nature of coke formation. The improved performance can be attributed to faster coke hydrogenation at increased pressure, overall resulting in a lower coke selectivity and better utilization of the zeolite micropore space. |
| Databáze: | OpenAIRE |
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