Researchers at the University of Pennsylvania and Harvard University published recent work using the Hummingbird Scientific in-situ gas cell TEM sample holder to investigate the effect of high temperature gas environments on the restructuring of Au0.75Pd0.25 catalyst nanoparticles. Nanoparticle evolution was analyzed using in-situ scanning transmission electron microscopy (STEM) with high-resolution energy dispersive X-ray spectroscopy (EDS) and electron energy loss spectroscopy (EELS).
- Air and O2 at 400 °C led to sharpening of the facets of particles, with small areas of segregated Pd.
- At 200 °C, CO exposure led to the loss of facets, while H2 exposure at 400 °C led to subtle increases to surface roughness.
- DFT calculations suggest that PdO reduction to Pd causes smaller facets and rougher edges.
Reference: Alexandre C. Foucher, Cameron J. Owen, Tanya Shirman, Joanna Aizenberg, Boris Kozinsky, and Eric A. Stach, J. Phys. Chem. C 126 (42) 18047-18056 (2022) DOI: 10.1021/acs.jpcc.2c05929 Abstract
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