Influence of gas atmospheres and ceria on the stability of nanoporous gold studied by environmental electron microscopy and In situ ptychography

Sina Baier, Arne Wittstock, Christian Danvad Damsgaard, Ana Diaz, Juliane Reinhardt, Federico Benzi, Junjie Shi, Torsten Scherer, Di Wang, Christian Kübel, Christian G. Schroer, Jan-Dierk Grunwaldt

Research output: Contribution to journalJournal articleResearchpeer-review

325 Downloads (Pure)

Abstract

A novel complementary approach of electron microscopy/environmental TEM and in situ hard X-ray ptychography was used to study the thermally induced coarsening of nanoporous gold under different atmospheres, pressures and after ceria deposition. The temperature applied during ptychographic imaging was determined by IR thermography. While using elevated temperatures (room temperature - 400 °C) and realistic gas atmospheres (1 bar) we achieved for the first time a spatial resolution of about 20 nm during hard X-ray ptychography. The annealing of pure and ceria stabilized nanoporous gold in different atmospheres revealed that the conditions have a tremendous influence on the coarsening. The porous structure of the samples was stable up to approximately 800 °C in vacuum, whereas pronounced changes and coarsening were observed already at approximately 300 °C in oxygen containing atmospheres. A layer of ceria on the nanoporous gold led to an improvement of the stability, but did not alleviate the influence of the gas atmosphere. Different behaviors were observed, such as coarsening and even material loss or migration. The results suggest that additional mechanisms beyond surface diffusion need to be considered and that microscopic studies aimed at more realistic conditions are important to understand the behavior of such materials and catalysts.
Original languageEnglish
JournalR S C Advances
Volume6
Pages (from-to)83031-83043
Number of pages13
ISSN2046-2069
DOIs
Publication statusPublished - 2016

Bibliographical note

This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence.

Cite this

Baier, Sina ; Wittstock, Arne ; Damsgaard, Christian Danvad ; Diaz, Ana ; Reinhardt, Juliane ; Benzi, Federico ; Shi, Junjie ; Scherer, Torsten ; Wang, Di ; Kübel, Christian ; Schroer, Christian G. ; Grunwaldt, Jan-Dierk. / Influence of gas atmospheres and ceria on the stability of nanoporous gold studied by environmental electron microscopy and In situ ptychography. In: R S C Advances. 2016 ; Vol. 6. pp. 83031-83043.
@article{42a2c20b643b4bcc8fef63a79767c07a,
title = "Influence of gas atmospheres and ceria on the stability of nanoporous gold studied by environmental electron microscopy and In situ ptychography",
abstract = "A novel complementary approach of electron microscopy/environmental TEM and in situ hard X-ray ptychography was used to study the thermally induced coarsening of nanoporous gold under different atmospheres, pressures and after ceria deposition. The temperature applied during ptychographic imaging was determined by IR thermography. While using elevated temperatures (room temperature - 400 °C) and realistic gas atmospheres (1 bar) we achieved for the first time a spatial resolution of about 20 nm during hard X-ray ptychography. The annealing of pure and ceria stabilized nanoporous gold in different atmospheres revealed that the conditions have a tremendous influence on the coarsening. The porous structure of the samples was stable up to approximately 800 °C in vacuum, whereas pronounced changes and coarsening were observed already at approximately 300 °C in oxygen containing atmospheres. A layer of ceria on the nanoporous gold led to an improvement of the stability, but did not alleviate the influence of the gas atmosphere. Different behaviors were observed, such as coarsening and even material loss or migration. The results suggest that additional mechanisms beyond surface diffusion need to be considered and that microscopic studies aimed at more realistic conditions are important to understand the behavior of such materials and catalysts.",
author = "Sina Baier and Arne Wittstock and Damsgaard, {Christian Danvad} and Ana Diaz and Juliane Reinhardt and Federico Benzi and Junjie Shi and Torsten Scherer and Di Wang and Christian K{\"u}bel and Schroer, {Christian G.} and Jan-Dierk Grunwaldt",
note = "This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence.",
year = "2016",
doi = "10.1039/c6ra12853j",
language = "English",
volume = "6",
pages = "83031--83043",
journal = "R S C Advances",
issn = "2046-2069",
publisher = "RSC Publishing",

}

Baier, S, Wittstock, A, Damsgaard, CD, Diaz, A, Reinhardt, J, Benzi, F, Shi, J, Scherer, T, Wang, D, Kübel, C, Schroer, CG & Grunwaldt, J-D 2016, 'Influence of gas atmospheres and ceria on the stability of nanoporous gold studied by environmental electron microscopy and In situ ptychography', R S C Advances, vol. 6, pp. 83031-83043. https://doi.org/10.1039/c6ra12853j

Influence of gas atmospheres and ceria on the stability of nanoporous gold studied by environmental electron microscopy and In situ ptychography. / Baier, Sina; Wittstock, Arne; Damsgaard, Christian Danvad; Diaz, Ana; Reinhardt, Juliane; Benzi, Federico; Shi, Junjie; Scherer, Torsten; Wang, Di; Kübel, Christian; Schroer, Christian G.; Grunwaldt, Jan-Dierk.

In: R S C Advances, Vol. 6, 2016, p. 83031-83043.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Influence of gas atmospheres and ceria on the stability of nanoporous gold studied by environmental electron microscopy and In situ ptychography

AU - Baier, Sina

AU - Wittstock, Arne

AU - Damsgaard, Christian Danvad

AU - Diaz, Ana

AU - Reinhardt, Juliane

AU - Benzi, Federico

AU - Shi, Junjie

AU - Scherer, Torsten

AU - Wang, Di

AU - Kübel, Christian

AU - Schroer, Christian G.

AU - Grunwaldt, Jan-Dierk

N1 - This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence.

PY - 2016

Y1 - 2016

N2 - A novel complementary approach of electron microscopy/environmental TEM and in situ hard X-ray ptychography was used to study the thermally induced coarsening of nanoporous gold under different atmospheres, pressures and after ceria deposition. The temperature applied during ptychographic imaging was determined by IR thermography. While using elevated temperatures (room temperature - 400 °C) and realistic gas atmospheres (1 bar) we achieved for the first time a spatial resolution of about 20 nm during hard X-ray ptychography. The annealing of pure and ceria stabilized nanoporous gold in different atmospheres revealed that the conditions have a tremendous influence on the coarsening. The porous structure of the samples was stable up to approximately 800 °C in vacuum, whereas pronounced changes and coarsening were observed already at approximately 300 °C in oxygen containing atmospheres. A layer of ceria on the nanoporous gold led to an improvement of the stability, but did not alleviate the influence of the gas atmosphere. Different behaviors were observed, such as coarsening and even material loss or migration. The results suggest that additional mechanisms beyond surface diffusion need to be considered and that microscopic studies aimed at more realistic conditions are important to understand the behavior of such materials and catalysts.

AB - A novel complementary approach of electron microscopy/environmental TEM and in situ hard X-ray ptychography was used to study the thermally induced coarsening of nanoporous gold under different atmospheres, pressures and after ceria deposition. The temperature applied during ptychographic imaging was determined by IR thermography. While using elevated temperatures (room temperature - 400 °C) and realistic gas atmospheres (1 bar) we achieved for the first time a spatial resolution of about 20 nm during hard X-ray ptychography. The annealing of pure and ceria stabilized nanoporous gold in different atmospheres revealed that the conditions have a tremendous influence on the coarsening. The porous structure of the samples was stable up to approximately 800 °C in vacuum, whereas pronounced changes and coarsening were observed already at approximately 300 °C in oxygen containing atmospheres. A layer of ceria on the nanoporous gold led to an improvement of the stability, but did not alleviate the influence of the gas atmosphere. Different behaviors were observed, such as coarsening and even material loss or migration. The results suggest that additional mechanisms beyond surface diffusion need to be considered and that microscopic studies aimed at more realistic conditions are important to understand the behavior of such materials and catalysts.

U2 - 10.1039/c6ra12853j

DO - 10.1039/c6ra12853j

M3 - Journal article

VL - 6

SP - 83031

EP - 83043

JO - R S C Advances

JF - R S C Advances

SN - 2046-2069

ER -