Cobalt-based catalysts are especially interesting from the commercial point of view due to their rather high activity and selectivity with respect to linear hydrocarbons. Furthermore, they exhibit higher stability, smaller negative effect of water on conversion and higher resistance to attrition in slurry bubble column reactors (Khodakov, 2009). Cobalt catalysts are only used for the LTFT process, as at higher temperatures, excess methane is produced (Dry, 2002). As the cost of cobalt is higher than that of Fe, it is desirable to increase the surface metal exposure, and therefore, Co-based catalysts are mostly supported on high-surface area stable supports such as Al2O3, TiO2 or SiO2 (Oukaci et al., 1999). Zeolites have also been studied as supports (Bessell, 1995). According to a review by Iglesia (1997), the use of support-precursor pairs with intermediate interaction strengths and the slow and controlled reduction of impregnated precursors appears to be the most promising route to the synthesis of supported Co catalysts with high Co concentrations and modest dispersions (0.10-0.15). SiO2 is considered the ideal support for Co FT catalysts, as its high surface area favours high Co dispersion at high Co loadings, while its surface chemistry enables high reduction of Co3+ or Co2+ to Co0 (Dalai and Davis, 2008). The latter is especially important, as metal Co is the active phase for FT and cobalt oxide is reduced at more than 300°C, temperature higher than the LTFT, implying that pre-reduction of the catalyst should take place prior to loading the reactor with consequent increase of cost and complexity. Promotion with small amounts of noble metals, for example Pt, Ru or Re, also enhances the reduction process (Iglesia et al., 1993). Although, in general, cobalt catalysts are less influenced by the presence of promoters than iron-based ones, the presence of noble metals is claimed to increase activity and selectivity to C5+ products via enhancement of the hydrogenolysis of the carbonaceous deposits and thus the cleaning of the catalytic surface (Iglesia et al., 1993).