Publications in Scientific Journals:

G. Parkinson, Z. Novotny, G. Argentero, M. Schmid, J. Pavelec, R. Kosak, P. Blaha, U. Diebold:
"Carbon monoxide-induced adatom sintering in a Pd-Fe_{3}O_{4} model catalyst";
Nature Materials, 12 (2013), 724 - 728.

English abstract:
The coarsening of catalytically active metal clusters is often
accelerated by the presence of gases, but the role played
by gas molecules is difficult to ascertain and varies from
system to system1-8. We use scanning tunnelling microscopy
to follow the CO-induced coalescence of Pd adatoms supported
on the Fe3O4(001) surface at room temperature, and find
Pd-carbonyl species to be responsible for mobility in this
system. Once these reach a critical density, clusters nucleate;
subsequent coarsening occurs through cluster diffusion and
coalescence. Whereas CO induces the mobility in the Pd=Fe3O4
system, surface hydroxyls have the opposite effect. Pd atoms
transported to surface OH groups are no longer susceptible
to carbonyl formation and remain isolated. Following the
evolution from well-dispersed metal adatoms into clusters,
atom-by-atom, allows identification of the key processes that
underlie gas-induced mass transport.

Created from the Publication Database of the Vienna University of Technology.