Coarsening of Pd nanoparticles in an oxidizing atmoshere studied by in situ TEM
Journal article, 2016

The coarsening of supported palladiumnanoparticles in an oxidizing atmospherewas studied in situ by means of transmission electron microscopy (TEM). Specifically, the Pd nanoparticles were dispersed on a planar and amorphous Al2O3 support and were observed during the exposure to 10 mbar technical air at 650 °C. Time-resolved TEM image series reveal that the Pd nanoparticles were immobile and that a few percent of the nanoparticles grew or shrank, indicating a coarsening process mediated by the Ostwald ripening mechanism. The TEM image contrast suggests that the largest nanoparticles tended to wet the Al2O3 support to a higher degree than the smaller nanoparticles and that the distribution of projected particle sizes consequently broadens by the appearance of an asymmetric tail toward the larger particle sizes. A comparison with computer simulations based on a simple mean-fieldmodel for the Ostwald ripening process indicates that the observed change in the particle size distribution can be accounted for by wetting of the Al2O3 support by the larger Pd nanoparticles.

Coarsening

Catalyst deactivation

In situ TEM

Sintering

Palladium

Ostwald ripening

Author

S. B. Simonsen

Haldor Topsoe

Ib Chorkendorff

Technical University of Denmark (DTU)

Søren Dahl

Haldor Topsoe

Magnus Skoglundh

Competence Centre for Catalysis (KCK)

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Applied Surface Chemistry

Stig Helveg

Haldor Topsoe

Surface Science

0039-6028 (ISSN)

Vol. 648 278-283

Driving Forces

Sustainable development

Innovation and entrepreneurship

Areas of Advance

Nanoscience and Nanotechnology (2010-2017)

Transport

Energy

Materials Science

Subject Categories

Physical Chemistry

Chemical Process Engineering

Condensed Matter Physics

Roots

Basic sciences

DOI

10.1016/j.susc.2015.11.003

More information

Latest update

3/27/2018