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This content will become publicly available on May 24, 2018

Title: The role of gas in determining image quality and resolution during in situ scanning transmission electron microscopy experiments

As gas-solid heterogeneous catalytic reactions are molecular in nature, a full mechanistic understanding of the process requires atomic scale characterization under realistic operating conditions. While atomic resolution imaging has become a routine in modern high-vacuum (scanning) transmission electron microscopy ((S)TEM), both image quality and resolution nominally degrade when reaction gases are introduced. In this work, we systematically assess the effects of different gases at various pressures on the quality and resolution of images obtained at room temperature in the annular dark field STEM imaging mode using a differentially pumped (DP) gas cell. This imaging mode is largely free from inelastic scattering effects induced by the presence of gases and retains good imaging properties over a wide range of gas mass/pressures. Furthermore, we demonstrate the application of the ESTEM with atomic resolution images of a complex oxide alkane oxidation catalyst MoVNbTeOx (M1) immersed in light and heavy gas environments.
Authors:
 [1] ;  [2]
  1. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
  2. Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Univ. of Washington, Seattle, WA (United States)
Publication Date:
Report Number(s):
PNNL-SA-126401
Journal ID: ISSN 1867-3880
Grant/Contract Number:
AC05-76RL01830; the Chemical Imaging Initiative
Type:
Accepted Manuscript
Journal Name:
ChemCatChem
Additional Journal Information:
Journal Volume: 9; Journal Issue: 18; Journal ID: ISSN 1867-3880
Publisher:
ChemPubSoc Europe
Research Org:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
OSTI Identifier:
1360184
Alternate Identifier(s):
OSTI ID: 1393996