Superhydrogenated PAHs: Catalytic formation of H2
| Autor: | Liv Hornekær, Ivan Stensgaard, Richard Balog, E. Rauls, A.C. Luntz, S. Baouche, Bjarke Jørgensen, J. D. Thrower, Louis Nilsson |
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| Rok vydání: | 2011 |
| Předmět: |
Physics
Direct evidence General Engineering Thermal desorption Astronomy and Astrophysics Photochemistry Coronene Lower limit law.invention Catalysis Interstellar medium chemistry.chemical_compound chemistry Space and Planetary Science law Density functional theory Scanning tunneling microscope Atomic physics |
| Zdroj: | EAS Publications Series. 46:453-460 |
| ISSN: | 1638-1963 1633-4760 |
| DOI: | 10.1051/eas/1146047 |
| Popis: | The possible role of neutral PAHs as catalysts for H2 forma- tion in the interstellar medium is investigated by a combined exper- imental and density function theory study of the superhydrogenation of coronene (C24H12). The calculations suggest efficient hydrogenation of both edge and centre sites, along with competing abstraction reac- tions to form H2 in a series of catalytic cycles. Scanning tunneling microscopy and thermal desorption measurements have been used to provide direct evidence of the formation of superhydrogenated coronene as a result of exposure to D atoms. Lower limit estimates for the cross- sections of 1.8×10 �17 ,5 .5×10 �18 and 1.1×10 �18 cm 2 for the formation of singly, doubly and triply hydrogenated coronene are derived. The results suggest that superhydrogenated PAHs may play an important role in H2 formation in the ISM. |
| Databáze: | OpenAIRE |
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