Ostwald ripening in a Pt/SiO2 model catalyst studied by in situ TEM
Artikel i vetenskaplig tidskrift, 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.
Nanoparticles
distributions
Sintering
mechanisms
v6
In situ TEM
v55
en m
oxidation
transmission electron-microscopy
akrave.bk
v28
thin-films
v114
2-dimensional islands
cabe rw
Ostwald ripening
critical radius
p2401
supported metal-catalysts
Catalyst deactivation
lean m
gamma-al2o3
1988
size
1978
1971
platinum/silica catalysts
p348
p354
p19
Pt
1967
Författare
S. B. Simonsen
Haldor Topsoe A/S
Danmarks Tekniske Universitet
I. Chorkendorff
Danmarks Tekniske Universitet
S. Dahl
Danmarks Tekniske Universitet
Magnus Skoglundh
Chalmers, Kemi- och bioteknik, Teknisk ytkemi
Kompetenscentrum katalys (KCK)
J. Sehested
Haldor Topsoe A/S
S. Helveg
Haldor Topsoe A/S
Journal of Catalysis
0021-9517 (ISSN) 1090-2694 (eISSN)
Vol. 281 1 147-155Drivkrafter
Hållbar utveckling
Styrkeområden
Nanovetenskap och nanoteknik
Transport
Energi
Materialvetenskap
Ämneskategorier (SSIF 2011)
Kemi
DOI
10.1016/j.jcat.2011.04.011