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.
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
Författare
S. B. Simonsen
Haldor Topsoe
Danmarks Tekniske Universitet (DTU)
I. Chorkendorff
Danmarks Tekniske Universitet (DTU)
S. Dahl
Danmarks Tekniske Universitet (DTU)
Magnus Skoglundh
Chalmers, Kemi- och bioteknik, Teknisk ytkemi
Kompetenscentrum katalys
J. Sehested
Haldor Topsoe
S. Helveg
Haldor Topsoe
Journal of Catalysis
0021-9517 (ISSN) 1090-2694 (eISSN)
Vol. 281 1 147-155Drivkrafter
Hållbar utveckling
Styrkeområden
Nanovetenskap och nanoteknik
Transport
Energi
Materialvetenskap
Ämneskategorier
Kemi
DOI
10.1016/j.jcat.2011.04.011