Quantitative Contrast Evaluation of an Industry-Style Rhodium Nanocatalyst with Single Atom Sensitivity
| Autor: | Christian Kisielowski, Oscar D. Dubon, Joo Kang, Robert J. Gulotty, P. Specht, Steve Rozeveld, David G. Barton, Robert C. Cieslinski |
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| Rok vydání: | 2011 |
| Předmět: |
inorganic chemicals
Materials science Phonon Organic Chemistry Analytical chemistry chemistry.chemical_element Aspect ratio (image) Acceleration voltage Molecular physics Catalysis Rhodium Characterization (materials science) Inorganic Chemistry chemistry Transmission electron microscopy Atom Surface roughness Physical and Theoretical Chemistry |
| Zdroj: | ChemCatChem. 3:1034-1037 |
| ISSN: | 1867-3880 |
| Popis: | Aberration-corrected electron microscopy opens new ways for material characterization. In catalyst research it will enable the observation of single atom arrangements, such as the location of promoter atoms on catalyst particles. However, quantitative procedures must be developed to account for dynamic contrast changes resulting from beam-sample interactions and incoherent instrument aberrations. We demonstrate that at low acceleration voltage (80 kV), for which knock-on damage is suppressed, the residual intensity fluctuations can be attributed to the presence of phonons resulting in 3D low frequency atom displacements. For rhodium [110] oriented particles it was found that the catalysts are platelets with an aspect ratio of about 0.2 and a surface roughness of ±1 atom. Observation of single surface atoms requires minimization of phonon-induced motion. |
| Databáze: | OpenAIRE |
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