Direct Observations of Oxygen-induced Platinum Nanoparticle Ripening Studied by In Situ TEM

Publication: Research - peer-reviewJournal article – Annual report year: 2010

View graph of relations

This study addresses the sintering mechanism of Pt nanoparticles dispersed on a planar, amorphous Al2O3 support as a model system for a catalyst for automotive exhaust abatement. By means of in situ transmission electron microscopy (TEM), the model catalyst was monitored during the exposure to 10 mbar air at 650 degrees C. Time-resolved image series unequivocally reveal that the sintering of Pt nanoparticles was mediated by an Ostwald ripening process. A statistical analysis of an ensemble of Pt nanoparticles shows that the particle size distributions change shape from an initial Gaussian distribution via a log-normal distribution to a Lifshitz-Slyozov-Wagner (LSW) distribution. Furthermore, the time-dependency of the ensemble-averaged particle size and particle density is determined. A mean field kinetic description captures the main trends in the observed behavior. However, at the individual nanoparticle level, deviations from the model are observed suggesting in part that the local environment influences the atom exchange process.
Original languageEnglish
JournalAmerican Chemical Society. Journal
Publication date2010
Volume132
Issue23
Pages7968-7975
ISSN0002-7863
DOIs
StatePublished
CitationsWeb of Science® Times Cited: 99
Download as:
Download as PDF
Select render style:
APAAuthorCBEHarvardMLAStandardVancouverShortLong
PDF
Download as HTML
Select render style:
APAAuthorCBEHarvardMLAStandardVancouverShortLong
HTML
Download as Word
Select render style:
APAAuthorCBEHarvardMLAStandardVancouverShortLong
Word

ID: 6326068