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Understanding catalyst behavior during in situ heating through simultaneous secondary and transmitted electron imaging.

ABSTRACT: By coupling techniques of simultaneous secondary (SE) and transmitted electron (TE) imaging at high resolution in a modern scanning transmission electron microscope (STEM), with the ability to heat specimens using a highly stable MEMS-based heating platform, we obtained synergistic information to clarify the behavior of catalysts during in situ thermal treatments. Au/iron oxide catalyst 'leached' to remove surface Au was heated to temperatures as high as 700°C. The Fe2O3 support particle structure tended to reduce to Fe3O4 and formed surface terraces; the formation, coalescence, and mobility of 1- to 2-nm particles on the terraces were characterized in SE, STEM-ADF, and TEM-BF modes. If combined with simultaneous nanoprobe spectroscopy, this approach will open the door to a new way of studying the kinetics of nano-scaled phenomena.

SUBMITTER: Howe JY

PROVIDER: S-EPMC4236855 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature

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Understanding catalyst behavior during in situ heating through simultaneous secondary and transmitted electron imaging.

Howe Jane Y JY Allard Lawrence F LF Bigelow Wilbur C WC Demers Hendrix H Overbury Steven H SH

Nanoscale research letters 20141114 1

By coupling techniques of simultaneous secondary (SE) and transmitted electron (TE) imaging at high resolution in a modern scanning transmission electron microscope (STEM), with the ability to heat specimens using a highly stable MEMS-based heating platform, we obtained synergistic information to clarify the behavior of catalysts during in situ thermal treatments. Au/iron oxide catalyst 'leached' to remove surface Au was heated to temperatures as high as 700°C. The Fe2O3 support particle structu ...[more]

PMID: 25419195

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