Thermal Stability of Metal Nanocrystals: An Investigation of the Surface and Bulk Reconstructions of Pd Concave Icosahedra [On the Thermal Stability of Metal Nanocrystals: An Investigation of the Surface and Bulk Reconstructions of Pd Concave Icosahedra]

Journal Article · Thu Apr 27 00:00:00 EDT 2017 · Nano Letters

DOI:https://doi.org/10.1021/acs.nanolett.7b00844· OSTI ID:1397260

Gilroy, Kyle D. ^[1]; Elnabawy, Ahmed O. ^[2]; Yang, Tung -Han ^[3]; Roling, Luke T. ^[2]; Howe, Jane ^[4]; Mavrikakis, Manos ^[2]; Xia, Younan ^[3]

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1. Georgia Inst. of Technology and Emory Univ., Atlanta, GA (United States); Department of Chemical and Biological Engineering, University of Wisconsin-Madison
2. Univ. of Wisconsin-Madison, Madison, WI (United States)
3. Georgia Inst. of Technology and Emory Univ., Atlanta, GA (United States)
4. Hitachi High-Technologies Canada, Toronto, ON (Canada)

Despite the remarkable success in controlling the synthesis of metal nanocrystals, it still remains a grand challenge to stabilize and preserve the shapes or internal structures of metastable kinetic products. In this work, we address this issue by systematically investigating the surface and bulk reconstructions experienced by a Pd concave icosahedron when subjected to heating up to 600 °C in vacuum. We used in situ high-resolution transmission electron microscopy to identify the equilibration pathways of this far-from-equilibrium structure. We were able to capture key structural transformations occurring during the thermal annealing process, which were mechanistically rationalized by implementing self-consistent plane-wave density functional theory (DFT) calculations. Specifically, the concave icosahedron was found to evolve into a regular icosahedron via surface reconstruction in the range of 200–400 °C, and then transform into a pseudospherical crystalline structure through bulk reconstruction when further heated to 600 °C. As a result, the mechanistic understanding may lead to the development of strategies for enhancing the thermal stability of metal nanocrystals.

• Research Organization: Univ. of Wisconsin-Madison, Madison, WI (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
• Contributing Organization: Environmental Molecular Sciences Laboratory; and the UW-Madison Center for High Throughput Computing (CHTC); the Center for Nanoscale Materials at Argonne National Laboratory; the National Energy Research Scientific Computing Center (NERSC)
• Grant/Contract Number: FG02-05ER15731
• OSTI ID: 1397260
• Journal Information: Nano Letters, Journal Name: Nano Letters Journal Issue: 6 Vol. 17; ISSN 1530-6984
• Publisher: American Chemical Society
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
Palladium
concave icosahedron
density functional theory
in situ electron microscopy
nanocrystal
thermal stability