A coupled AFM-Raman system was used to study the surface heterogeneity of catalytic materials at various stages of their preparation. The catalysts chosen for the analyses were cobalt oxide with and without palladium dopant deposited on surface of pre-calcined steel carriers. Steel carriers are surveyed here in terms of their application as fillers for structured reactors for the catalytic combustion of volatile organic compounds. Upon steel precalcination stage the interfaced AFM-Raman and in situ Raman analyses revealed the evolution of alumina and iron oxide phases on the surface with their final stable forms found as being α-Al_{2}O_{3} and α-Fe_{2}O_{3}. Upon catalyst layering stage AFM-Raman mapping evidenced uniform coverage of precalcined steel carrier with cobalt spinel oxide Co_{3}O_{4}. For the doped catalyst except Co_{3}O_{4} palladium(II) oxide grains were also found on the surface. The differences in the composition of cobalt catalysts were correlated with the differences in their catalytic activity.