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High-resolution Thermal Micro-imaging Using Europium Chelate Luminescent Coatings
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Understanding catalyst behavior during in situ heating through simultaneous secondary and transmitted electron
Jane Y Howe1, Lawrence F Allard2, Wilbur C Bigelow3
1Physical Sciences Directorate, Oak Ridge National Laboratory, 1 Bethel Valley Rd, TN 37831 Oak Ridge, USA ; Hitachi High-Technologies Canada Inc, 89 Galaxy Blvd, Toronto, ON M9W 6A4, Canada.
Nanoscale Research Letters
|November 25, 2014
Summary
This study reveals how iron oxide catalysts transform at high temperatures using advanced electron microscopy. It details particle changes and surface restructuring during thermal treatments for better catalyst understanding.
Area of Science:
- Materials Science
- Catalysis Science
- Surface Science
Background:
- Understanding catalyst behavior under thermal stress is crucial for optimizing industrial processes.
- High-resolution imaging techniques are needed to observe dynamic changes at the nanoscale.
Purpose of the Study:
- To investigate the structural and morphological evolution of Au/iron oxide catalysts during in situ thermal treatments.
- To elucidate the behavior of nanoparticles on catalyst supports at elevated temperatures.
Main Methods:
- Utilizing a scanning transmission electron microscope (STEM) equipped for simultaneous secondary electron (SE) and transmitted electron (TE) imaging.
- Employing a stable MEMS-based heating platform for in situ thermal treatments up to 700°C.
- Characterizing nanoparticle formation, coalescence, and mobility using SE, STEM-ADF, and TEM-BF imaging modes.
Main Results:
- Observed reduction of Fe2O3 support to Fe3O4 with the formation of surface terraces upon heating.
- Detailed the formation, coalescence, and mobility of 1- to 2-nm particles on these terraces.
- Demonstrated the capability to track nanoscale phenomena during thermal cycling.
Conclusions:
- The combined SE/TE imaging and in situ heating approach provides synergistic insights into catalyst behavior.
- This methodology offers a powerful platform for studying the kinetics of nano-scaled phenomena in catalysts.
- Future integration with nanoprobe spectroscopy will further enhance in situ catalyst research.
Keywords:
CatalystIn situ characterizationPhase transformationScanning electron microscopyScanning transmission electron microscopyMore Related Videos
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