The CO oxidation reaction is an environmentally important reaction. Due to the toxic character of CO, the lowering of its content in the car exhaust is still one of the focus points of modern commercial catalysis. Conventional TWCs, which are used for purifying the car exhaust from CO, are composed of noble metal nanoparticles supported by different oxidic supports. The catalytically active noble metal nanoparticles expose different facets, whose crystallographic orientations do not necessary fit to low Miller index planes. Therefore, studies of stepped transition metal surfaces are highly up to date. In the present thesis, catalytic properties of stepped (111)-, (100)- and (110)- type vicinal Rh surfaces, formed on m-sized domains on a polycrystalline Rh foil, were studied by PEEM using kinetics by imaging approach. Comparison of the local kinetics phase diagrams constructed for (111)-, (100)- vicinal Rh surfaces at identical reaction conditions revealed an influence of the density of steps on catalytic performance of stepped Rh surfaces: an increase of density of steps on leads to an increase of the tolerance of these surfaces towards CO poisoning. However, for the case of (110)-type vicinal Rh surfaces, the opposite effect was observed. It was proposed, that the reason of this "opposite behavior" of (110)-type vicinal Rh surfaces originates from the formation of subsurface oxygen, which can alter the catalytic behaviour. The suggestion about the formation of subsurface oxygen, was supported by experiments with H2 oxidation on the same polycrystalline Rh foil. The formation of regions of reduced work function which indicate formation of subsurface oxygen, was observed by PEEM. Beside the stepped Rh surfaces, m-sized Pd powder agglomerates supported by ZrOx and by Pt were studied in order to demonstrate the effect of oxidic support on the catalytic properties of Pd using the same experimental approach. It was revealed that by changing the type of supporting material, catalytic properties of supported Pd changes remarkably: the oxide-supported Pd exhibits significantly higher tolerance towards CO poisoning. To reveal the details of the role of an oxidic support on the catalytic performance of supported Pd, the influence of thickness of the oxidic support on the catalytic performance of the model system was studied. This study revealed an observable effect of the oxide layer thickness on the catalytic properties of supported Pd: an increase of the supporting oxide layer thickness leads to an increase of the tolerance of the supported Pd model system towards CO poisoning. In this context, the composition of the supporting ZrOx layer was studied in detail by the investigation of initial oxidation of polycrystalline Zr surfaces using XPS and PEEM. Analysis of XPS data revealed the formation of substoichometric oxidic species at low oxygen exposure. It was shown, that during the first (fast) oxidation stage, the formation of the Zr suboxide interlayer consisting of three suboxidic components (Zr+1, Zr+2 and Zr+3), which are located between the metallic Zr surface and a stoichiometric ZrO2 overlayer, takes place, whereas at very low oxygen exposure (about 4 L) a sole suboxide layer forms. Formation of the stoichiometric ZrO2 overlayer occurs during the second (slow) oxidation stage. In situ observations of the initial oxidation of polycrystalline Zr at the same condition as in XPS, but in PEEM are in agreement with the two stage oxidation model.