The locally resolved kinetics of CO oxidation on individual (111), (110) and (100) domains of a polycrystalline Pt foil were obtained by intensity analysis of video-PEEM images (see picture), and are compared to the global kinetics determined simultaneously by mass spectroscopy. The individual domains behave independently, with the propagating reaction fronts being confined within the grain boundaries

An improved methodology of the Zr specimen preparation was developed which allows fabrication of stable Zr nanotips suitable for FIM and AP applications. Initial oxidation of the Zr surface was studied on a Zr nanotip by FIM and on a polycrystalline Zr foil by XPS, both at low oxygen pressure (10−8–10−7 mbar). The XPS data reveal that in a first, fast stage of oxidation, a Zr suboxide interlayer is formed which contains three suboxide components (Zr+1, Zr+2 and Zr+3) and is located between the Zr surface and a stoichiometric ZrO2 overlayer that grows in a second, slow oxidation stage. The sole suboxide layer has been observed for the first time at very early states of the oxidation (oxygen exposure ≤4 L). The Ne+ FIM observations are in accord with a two stage process of Zr oxide formation.

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The reaction kinetics of catalytic CO oxidation on individual grains of a polycrystalline Pt foil has been studied simultaneously by photoemission electron microscopy (PEEM) and mass spectroscopy (MS), in the pressure range ~10−5 mbar. By processing the video-PEEM images of ongoing catalytic reaction, the kinetic transitions were tracked for individual [110]-oriented domains. The obtained local kinetic phase diagrams were contrasted to those obtained from global MS activity measurements. These data and the observation of reaction front propagation on different Pt(110) domains indicate a quasi-independent behaviour of the crystallographic domains. The observed front propagation velocities and the degree of their anisotropy on Pt foil corroborate earlier observations on Pt(110) single crystals, confirming our concept of using Pt foil to monitor and compare different surface terminations in parallel