The effect of steam gasification on the surface composition, surface area, pore size distribution as well as on the morphology of the carbon supports has been investigated. Materials have been characterized by nitrogen physisorption, mercury porosimetry, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Model samples of the Co–Mo–K catalysts with the same composition have been prepared on carbon supports differing in the temperature of steam gasification process. Catalytic activity measurements have been carried out in a gradientless reactor in a kinetic regime at low partial pressures of reagents. A relationship between textural parameters of the supports and the catalysts activity has been estimated. The highest activity in the SGS process has been determined for the Co–Mo–K/SRO/40.49 supported catalyst.