A fundamental study concerning the preparation of porous alumina washcoats in microchannels for the application in heterogeneous gas phase catalysis was performed, focusing on the pre-treatment of the micro structures, properties, and adhesion of the washcoats as well as the testing of the prepared catalysts. Steel microstructures, which are manufactured by wet-chemical etching with chloride solutions, show significant chlorine content at the surface due to the etchant. Anodic oxidation and thermal treatment of the microstructures significantly reduce the undesirable chlorine content, which is assumed to have deleterious effects on the catalyst activity. Good adhesion of the porous catalysts, deposited by a two-step process, washcoating and wet impregnation, was demonstrated by a mechanical test. Cross-sectional profile accuracy was reasonable and reliable. At the example of a CuO/Cr2O3/Al2O3 system, the distribution of the impregnated components within the washcoat, in lateral (depth of the coating) and horizontal directions (at the coating's surface), was studied by secondary ion mass spectrometry (SIMS). It turned out that Cr2O3 was homogeneously distributed both in horizontal and lateral direction, whereas the content of CuO decreased with the washcoat depth and islands of accumulated material on the surface were formed. The activity of the CuO/Cr2O3/Al2O3 system was investigated using different alumina carriers for methanol steam reforming. The activity found was correlated with the total catalyst surface area offered to the reaction system.