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 α-Al 2 O 3 although there are places where α-Fe 2 O 3 and Fe 3 O 4 are also present. Washcoating of the precalcined sheets gives only partly uniform grain distribution of CeO 2 . Impregnation with cobalt leads to formation of uniform coverage of Co 3 O 4 . 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 stability of cobalt palladium doped catalysts deposited directly on the precalcined steel than was correlated with the presence of PdO phase.