Coarsening of carbon black supported Pt nanoparticles in hydrogen

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Abstract

This study addresses coarsening mechanisms of Pt nanoparticles supported on carbon black in hydrogen. By means of in situ transmission electron microscopy (TEM), Pt nanoparticle coarsening was monitored in 6 mbar 20 % H2/Ar while ramping up the temperature to almost 1000 °C. Time-resolved TEM images directly reveal that separated ca. 3 nm sized Pt nanoparticles in a hydrogen environment are stable up to ca. 800 °C at a heating rate of 10 °C/min. The coarsening above this temperature is dominated by the particle migration and coalescence mechanism. However, for agglomerated Pt nanoparticles, coalescence events were observed already above 200 °C. The temperature-dependency of particle sizes and the observed migration distances are described and found to be consistent with simple early models for the migration and coalescence.
Original languageEnglish
Article number475710
JournalNanotechnology
Volume28
Issue number47
Number of pages9
ISSN0957-4484
DOIs
Publication statusPublished - 2017

Keywords

  • Pt nanoparticle
  • catalyst
  • coarsening
  • in situ TEM

Cite this

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title = "Coarsening of carbon black supported Pt nanoparticles in hydrogen",
abstract = "This study addresses coarsening mechanisms of Pt nanoparticles supported on carbon black in hydrogen. By means of in situ transmission electron microscopy (TEM), Pt nanoparticle coarsening was monitored in 6 mbar 20 {\%} H2/Ar while ramping up the temperature to almost 1000 °C. Time-resolved TEM images directly reveal that separated ca. 3 nm sized Pt nanoparticles in a hydrogen environment are stable up to ca. 800 °C at a heating rate of 10 °C/min. The coarsening above this temperature is dominated by the particle migration and coalescence mechanism. However, for agglomerated Pt nanoparticles, coalescence events were observed already above 200 °C. The temperature-dependency of particle sizes and the observed migration distances are described and found to be consistent with simple early models for the migration and coalescence.",
keywords = "Pt nanoparticle, catalyst, coarsening, in situ TEM",
author = "Simonsen, {S{\o}ren Bredmose} and Yan Wang and Jensen, {Jens Oluf} and Zhang, {Wenjing (Angela)}",
year = "2017",
doi = "10.1088/1361-6528/aa91a8",
language = "English",
volume = "28",
journal = "Nanotechnology",
issn = "0957-4484",
publisher = "IOP Publishing",
number = "47",

}

Coarsening of carbon black supported Pt nanoparticles in hydrogen. / Simonsen, Søren Bredmose ; Wang, Yan; Jensen, Jens Oluf; Zhang, Wenjing (Angela).

In: Nanotechnology, Vol. 28, No. 47, 475710, 2017.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Coarsening of carbon black supported Pt nanoparticles in hydrogen

AU - Simonsen, Søren Bredmose

AU - Wang, Yan

AU - Jensen, Jens Oluf

AU - Zhang, Wenjing (Angela)

PY - 2017

Y1 - 2017

N2 - This study addresses coarsening mechanisms of Pt nanoparticles supported on carbon black in hydrogen. By means of in situ transmission electron microscopy (TEM), Pt nanoparticle coarsening was monitored in 6 mbar 20 % H2/Ar while ramping up the temperature to almost 1000 °C. Time-resolved TEM images directly reveal that separated ca. 3 nm sized Pt nanoparticles in a hydrogen environment are stable up to ca. 800 °C at a heating rate of 10 °C/min. The coarsening above this temperature is dominated by the particle migration and coalescence mechanism. However, for agglomerated Pt nanoparticles, coalescence events were observed already above 200 °C. The temperature-dependency of particle sizes and the observed migration distances are described and found to be consistent with simple early models for the migration and coalescence.

AB - This study addresses coarsening mechanisms of Pt nanoparticles supported on carbon black in hydrogen. By means of in situ transmission electron microscopy (TEM), Pt nanoparticle coarsening was monitored in 6 mbar 20 % H2/Ar while ramping up the temperature to almost 1000 °C. Time-resolved TEM images directly reveal that separated ca. 3 nm sized Pt nanoparticles in a hydrogen environment are stable up to ca. 800 °C at a heating rate of 10 °C/min. The coarsening above this temperature is dominated by the particle migration and coalescence mechanism. However, for agglomerated Pt nanoparticles, coalescence events were observed already above 200 °C. The temperature-dependency of particle sizes and the observed migration distances are described and found to be consistent with simple early models for the migration and coalescence.

KW - Pt nanoparticle

KW - catalyst

KW - coarsening

KW - in situ TEM

U2 - 10.1088/1361-6528/aa91a8

DO - 10.1088/1361-6528/aa91a8

M3 - Journal article

VL - 28

JO - Nanotechnology

JF - Nanotechnology

SN - 0957-4484

IS - 47

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