Ostwald ripening in a Pt/SiO2 model catalyst studied by in situ TEM
Journal article, 2011
Sintering of Pt nanoparticles dispersed on a planar SiO(2) support was studied by in situ transmission electron microscopy (TEM). A time-lapsed TEM image series of the Pt nanoparticles, acquired during the exposure to 10 mbar synthetic air at 650 degrees C, reveal that the sintering was governed by the Ostwald ripening mechanism. The in situ TEM images also provide information about the temporal evolution of the Pt particle size distribution and of the growth or decay of the individual nanoparticles. The observed Pt nanoparticle changes compare well with predictions made by mean-field kinetic models for ripening, but deviations are revealed for the time-evolution for the individual nanoparticles. A better description of the individual nanoparticle ripening is obtained by kinetic models that include local correlations between neighboring nanoparticles in the atom-exchange process.
platinum/silica catalysts
p19
size
Sintering
gamma-al2o3
en m
In situ TEM
lean m
p2401
critical radius
1988
p348
1971
1967
transmission electron-microscopy
1978
thin-films
distributions
cabe rw
Pt
oxidation
Catalyst deactivation
v55
Nanoparticles
v6
mechanisms
v28
p354
akrave.bk
supported metal-catalysts
v114
2-dimensional islands
Ostwald ripening
Author
S. B. Simonsen
Haldor Topsoe
Technical University of Denmark (DTU)
I. Chorkendorff
Technical University of Denmark (DTU)
S. Dahl
Technical University of Denmark (DTU)
Magnus Skoglundh
Chalmers, Chemical and Biological Engineering, Applied Surface Chemistry
Competence Centre for Catalysis (KCK)
J. Sehested
Haldor Topsoe
S. Helveg
Haldor Topsoe
Journal of Catalysis
0021-9517 (ISSN) 1090-2694 (eISSN)
Vol. 281 1 147-155Driving Forces
Sustainable development
Areas of Advance
Nanoscience and Nanotechnology
Transport
Energy
Materials Science
Subject Categories
Chemical Sciences
DOI
10.1016/j.jcat.2011.04.011