The dynamics of the dissociative adsorption of alkanes on Ir(110)

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Details zur Publikation

Autorinnen und Autoren: Hamza A, Steinrück HP, Madix R
Zeitschrift: Journal of Chemical Physics
Verlag: American Institute of Physics (AIP)
Jahr der Veröffentlichung: 1987
Band: 86
Heftnummer: 11
Seitenbereich: 6506-6514
ISSN: 0021-9606
eISSN: 1089-7690


The dissociative adsorption of C-C alkanes on Ir(110)-(1×2) was investigated using supersonic molecular beam techniques. Three regimes of reactivity were observed. At incident kinetic energies less than 100 kJ/mol the dissociative adsorption probability for propane and butane increased to about 0.6 with both decreasing surface temperature and decreasing translational energy of the incident molecule suggesting that activation occured via trapping of the alkane on the surface. At kinetic energies below 110 kJ/mol for butane, 90 kJ/mol for propane, 60 kJ/mol for ethane, 40 kJ/mol for methane, and at elevated surface temperatures the reaction probabilities for alkanes were independent of surface temperature and translational energy, but increased significantly with the molecular weight or carbon chain length of the incident alkane. This behavior indicates an unactivated reaction channel for each species except methane. At kinetic energies above 110 kJ/mol for butane, 90 kJ/mol for propane, 60 kJ/mol for ethane, and 40 kJ/mol for methane the initial dissociative sticking probability increased with increasing translational energy and was independent of surface temperature, indicating direct translational activation of the incident alkane. The translational energy required to activate the incident alkane via this channel increased with carbon number or molecular weight, indicative of energy transfer processes that dissipate energy in the reactive collision. The dissipative transfer of translational energy out of the reactive channel via a hard cube collision with the surface accounts qualitatively for the increase in the apparent activation barrier with increasing molecular weight in this activated channel. © 1987 American Institute of Physics.

FAU-Autorinnen und Autoren / FAU-Herausgeberinnen und Herausgeber

Steinrück, Hans-Peter Prof. Dr.
Lehrstuhl für Physikalische Chemie II

Einrichtungen weiterer Autorinnen und Autoren

Lawrence Livermore National Laboratory
Stanford University


Hamza, A., Steinrück, H.-P., & Madix, R. (1987). The dynamics of the dissociative adsorption of alkanes on Ir(110). Journal of Chemical Physics, 86(11), 6506-6514.

Hamza, Alex, Hans-Peter Steinrück, and R.J. Madix. "The dynamics of the dissociative adsorption of alkanes on Ir(110)." Journal of Chemical Physics 86.11 (1987): 6506-6514.


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