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

نویسندگان

  • Jane Y Howe
  • Lawrence F Allard
  • Wilbur C Bigelow
  • Hendrix Demers
  • Steven H Overbury
چکیده

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.

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عنوان ژورنال:

دوره 9  شماره 

صفحات  -

تاریخ انتشار 2014