https://doi.org/10.1140/epjd/e2003-00185-6
Size dependent reaction kinetics of small gold clusters with carbon monoxide: Influence of internal degrees of freedom and carbonyl complex stability
1
Institut für Experimentalphysik, Freie Universität
Berlin, Arnimallee 14, 14195 Berlin, Germany
2
Abteilung für
Oberflächenchemie und Katalyse, Universität Ulm, 89069 Ulm,
Germany
Corresponding author: a tbernhar@physik.fu-berlin.de
Received:
10
September
2002
Published online:
3
July
2003
The reactions of free gold clusters Au-,
Au
, and Au
with carbon monoxide are studied in an
rf-octopole ion trap experiment at cryogenic temperatures. While
Au- is unreactive toward CO over the whole temperature range
investigated, the two and three atom cluster anions show a maximum
adsorption of two CO molecules at temperatures below 250 K. From
time resolved trapping experiments the strongly cluster size
dependent reaction kinetics are obtained and a distinct reaction
mechanism is deduced. The size dependence of the measured rate
coefficients reveals the preferred formation and particular
stability of the carbonyl complex Au3(CO). Through RRK analysis of the absolute
termolecular rate coefficients we are able to estimate the binding
energy of CO to Au and Au.
PACS: 36.40.Jn – Reactivity of clusters / 82.30.Fi – Ion-molecule, ion-ion, and charge-transfer reactions / 82.80.Ms – Mass spectrometry (including SIMS, multiphoton ionization and resonance ionization mass spectrometry, MALDI)
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2003
