Regensburg 2007 – scientific programme

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O: Fachverband Oberflächenphysik

O 17: Poster Session I (Nanostructures at Surfaces; Metal Substrates: Epitaxy and Growth; Methods: Scanning Probe Techniques; Phase Transitions)

O 17.44: Poster

Monday, March 26, 2007, 17:30–20:30, Poster C

Scanning mass spectrometer setup for spatially resolved reactivity studies on model catalysts — •Matthias Roos, Christian Schirling, Stefan Kielbassa, Joachim Bansmann, and Jürgen Behm — Institut für Oberflächenchemie und Katalyse, Universität Ulm, D-89069 Ulm

A scanning mass spectrometer with micrometer-scale resolution was developed for investigations on the catalytic activity of microstructured planar model catalysts. Products of local surface reactions can be detected via a fine capillary orifice in a differentially pumped quadrupole mass spectrometer. The position of the sample with respect to the capillary is controlled by three piezo-driven translators. The surface reactivity of a resistive heated sample can be depicted in a spatially resolved topogram, taking into account the influence of the distance between sample and capillary on the magnitude of the QMS signal and the lateral resolution.

Photolithographic structured reactive patterns on top of an inactive substrate enable investigations of mesoscopic transport effects such as coupling between catalytically active areas and of (reverse) spillover phenomena on one sample by varying the size and the distances of the active areas.