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I. Bespalov, M. Datler, G. Rupprechter, Y. Suchorski:
"Compatibility of the nm-scale and µm-scale studies of the catalytic CO oxidation on Pd: FIM/FEM versus PEEM";
Poster: International Conference on Atom Probe Tomography & Microscopy, Stuttgart; 31.08.2014 - 05.09.2014; in: "APT&M", (2014), S. 216.

Catalytic CO oxidation on Pd has been studied in situ on the nm-sized facets of a Pd nanotip using FIM and FEM, and, alternatively, on the µm-sized Pd powder agglomerations supported by ZrO2 using PEEM. In order to examine the compatibility of results from the two length scales, the regions of different catalytic behavior (kinetic phase diagram) have been mapped out in pCO,T-parameter space for the both classes of samples. Significant shifts of the FEM- and FIM-determined kinetic phase diagrams (for nanotips, nm-scale) in respect to the diagrams measured by PEEM for the Pd powder and (earlier) for the individual Pd(hkl) domains of a polycrystalline Pd foil could be observed.
The use of the pulsed imaging field (less than 5 V·nm−1, with varying duration of the pulses) in the FEM allows to exclude the field-effects, the differences in the positioning of the regions of the high- and low-activity between the Pd-nanofacets and Pd-powder agglomerates are primarily morphology-caused. In turn, the additional shift of the kinetic phase diagram observed with FIM, can be explained in terms of a field-modified interaction of CO and O2 with Pd surface.

CO oxidation, Catalysis, FIM, FEM, PEEM; Pd