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Tracking dynamic structural changes in catalysis by rapid 2D-XANES microscopy
- Source :
- Journal of synchrotron radiation 28(5), 1518-1527 (2021). doi:10.1107/S1600577521007074, Journal of Synchrotron Radiation, Journal of synchrotron radiation, 28 (5)
- Publication Year :
- 2021
- Publisher :
- Wiley-Blackwell, 2021.
-
Abstract
- Journal of synchrotron radiation 28(5), 1518 - 1527 (2021). doi:10.1107/S1600577521007074<br />Many processes and materials in heterogeneous catalysis undergo dynamic structural changes depending on their chemical environment. Monitoring such dynamic changes can be challenging using conventional spectroscopic characterization tools, due to the high time resolution required. Here, a high-resolution 2D X-ray camera operating at 50 Hz full-frame rate was synchronized with a QEXAFS monochromator, enabling rapid spectro-microscopic imaging with chemical contrast over individual pixels. This was used to monitor chemical gradients within a model Pt/Al2O3 catalyst during catalytic partial oxidation of methane to synthesis gas. The transition from methane combustion (partly oxidized Pt) to combustion-reforming and partial oxidation (fully reduced Pt) was observed by a characteristic reduction front, which progressed from the end of the catalyst bed towards its beginning on the second time scale. The full-field QEXAFS imaging method applied here allows acquisition of entire XANES spectra `on the fly' in a rapid and spatially resolved manner. The combination of high spatial and temporal resolution with spectroscopic data offers new opportunities for observing dynamic processes in catalysts and other functional materials at work. The methodology is flexible and can be applied at beamlines equipped with a QEXAFS or other fast-scanning monochromators and a suitable sample environment for gas phase analytics to allow for catalytic studies at the same time.<br />Published by Wiley-Blackwell, [S.l.]
- Subjects :
- Technology
Nuclear and High Energy Physics
Materials science
Heterogeneous catalysis
Methane
Catalysis
law.invention
chemistry.chemical_compound
law
QEXAFS
ddc:550
X-ray microscopy
Partial oxidation
Instrumentation
in situ and operando
Monochromator
Radiation
Research Papers
XANES
Characterization (materials science)
heterogeneous catalysis
chemistry
Chemical physics
Temporal resolution
ddc:600
Subjects
Details
- Language :
- English
- ISSN :
- 16005775
- Database :
- OpenAIRE
- Journal :
- Journal of synchrotron radiation 28(5), 1518-1527 (2021). doi:10.1107/S1600577521007074, Journal of Synchrotron Radiation, Journal of synchrotron radiation, 28 (5)
- Accession number :
- edsair.doi.dedup.....07a6131971f08a9576a34f3039a8b907