Abstract
We have developed methods for using in situ electron energy-loss spectroscopy (EELS) to perform quantitative analysis of gas in an environmental transmission electron microscope. Inner-shell EELS was able to successfully determine the composition of gas mixtures with an accuracy of about 15% or better provided that some precautions are taken during the acquisition to account for the extended gas path lengths associated with the reaction cell. The unique valence-loss spectrum associated with many gases allowed simple methodologies to be developed to determine gas composition from the low-loss region of the spectrum from a gas mixture. The advantage of the valence loss approach is that it allows hydrogen to be detected and quantified. EELS allows real-time analysis of the volume of gas inside the reaction cell and can be performed rapidly with typical acquisition times of a few seconds or less. This in situ gas analysis can also be useful for revealing mass transport issues associated with the differential gas diffusion through the system.
Original language | English (US) |
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Pages (from-to) | 177-185 |
Number of pages | 9 |
Journal | Ultramicroscopy |
Volume | 111 |
Issue number | 3 |
DOIs | |
State | Published - Feb 2011 |
Keywords
- Catalysts
- EELS
- Environmental
- Gas
- In situ
- TEM
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Instrumentation