Flame spray pyrolysis (FSP) is an innovative and scalable technique, used to synthesize monometallic and bimetallic Co-Ru catalysts with 5% wt. Co, 10% wt. Co and 0.4% wt. Ru supported on SiO2 active in the Gas-to-Liquids (GTL)-Fischer-Tropsch (FT) process, which converts syngas to hydrocarbons. The catalysts were characterized by TEM, FE-SEM-EDX, TPR, XRD and N2 adsorption/desorption. All the three samples have been tested in a fixed bed FT-bench scale plant. Results demonstrated that the 5% wt. Co catalyst was not active toward FT synthesis, while samples containing 10% wt. Co and 10% wt. Co - 0.4% wt. Ru were suitable candidates for the GTL-FT process. With an increase in temperature, the CO conversion increased, the product selectivity remained unchanged, and the 10% wt. Co catalyst showed higher stability as a function of time-on-stream (TOS) with respect to traditionally prepared materials. The addition of 0.4% wt. of Ru improved the performance in terms of CO conversion and C2+ yield.