Adsorption of Propene on Neutral Gold Clusters in the Gas Phase.
The adsorption of propene on neutral gold clusters is investigated in a collision cell under a few collision conditions. The adsorption reaction is studied by pressure-dependent kinetic measurements and delayed unimolecular dissociation of the excited Aun propene complexes. The cluster size (n=9-25) and temperature (T=90-300 K) dependence of the propene adsorption is analyzed. Strong size dependences of the absorption reaction are observed; a larger propene adsorption probability was found for gold clusters composed of an even number of atoms. Propene binding energies are estimated by comparison of the temperature-dependent unimolecular dissociation rates with rates obtained by using statistical RRKM modeling. The Aun -propene binding energies decrease non-monotonously with cluster size and are in the range of 1.2-0.85 eV for n=9-25. Finally, the bonding of C3 H6 on Aun is qualitatively described and similarities with the absorption of CO molecules on gold clusters are discussed.
Laboratory of Solid State Physics and Magnetism, KU Leuven, Celestijnenlaan 200d-box 2414, 3001 Leuven (Belgium). ewald.janssens@fys.kuleuven.be.
Ewald
E
Janssens
Laboratory of Solid State Physics and Magnetism, KU Leuven, Celestijnenlaan 200d-box 2414, 3001 Leuven (Belgium).
Hai Thuy
HT
Le
Laboratory of Solid State Physics and Magnetism, KU Leuven, Celestijnenlaan 200d-box 2414, 3001 Leuven (Belgium).
Peter
P
Lievens
adsorption; cluster compounds; gas-phase reactions; gold; kinetics