A system of interfaced AFM and Raman microscopes was used to study heterogeneity of complex catalytic materials providing information on both the topography and the chemical composition of the surface in one measurement. The catalysts surface was examined at various stages of their preparation: precalcination of steel, washcoating, impregnation and doping. It has been shown that the surface of the precalcined steel sheets is covered mostly by alpha-Al2O3 although there are places where alpha-Fe2O3 and Fe3O4 are also present. Washcoating of the precalcined sheets gives only partly uniform grain distributionof CeO2. Impregnation with cobalt leads to formation of uniform coverage of Co3O4. Depending on the presence or absence of ceria washcoat layer, palladium doped to the cobalt catalyst may give dispersed Pd-0 grains or large grains of PdO, respectively. High n-nonane combustion activity and thermal stabilityof cobalt palladium doped catalysts deposited directly on the precalcined steel than was correlated with the presence of PdO phase. (C) 2013 Elsevier B.V. All rights reserved.