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Phenomenological in-situ TEM gas exposure studies of palladium particles on MgO at room temperatureIt has been found that very small vapor-deposited catalytically active metal particles in the 1-2 nm size range on metal oxide substrates can undergo significant changes when they are exposed to gases such as oxygen or air, or even when allowed to 'anneal' at room temperature (RT) under vacuum conditions. The present investigation is concerned with continued in-situ gas exposures of as-deposited, 1 to 2 nm size palladium particles on MgO to air, oxygen, nitrogen, hydrogen, CO, and water vapor at RT. It is found that the low-pressure exposure to various gases at RT can significantly affect small palladium particles supported on MgO surfaces. Exposure to oxygen for 3 min at 0.0002 m bar produces a considerable amount of coalescence, flattening of the particles, and some distinct crystallographic particle shapes.
Document ID
19840058213
Document Type
Reprint (Version printed in journal)
Authors
Heinemann, K. (Stanford Univ. CA, United States)
Poppa, H. (Stanford University Stanford, CA, United States)
Osaka, T. (Stanford Univ. CA, United States)
Date Acquired
August 12, 2013
Publication Date
January 1, 1983
Publication Information
Publication: Ultramicroscopy
Issue: 12 1
ISSN: 0304-3991
Subject Category
CHEMISTRY AND MATERIALS (GENERAL)
Funding Number(s)
CONTRACT_GRANT: NCC2-171
Distribution Limits
Public
Copyright
Other