Due to the high activity of cobalt metal in synthesis gas conversion to higher hydrocarbons, supported cobalt catalysts have been widely used for gas-to-liquids conversion. A study on effects support type and gas space velocity on the catalytic performance of 15 wt % Co on three supports (γ-Al 2O 3, SiO 2, and TiO 2) was carried out. The existence of two step reduction of Co 3O 4 was observed. Degree of reduction was ≈ 93% and dispersion 8.6%, whereas cobalt was completely reduced on silica and titania supports. Dispersions on these two supports were 2.4% and 3.2%, respectively. Turnover frequencies (TOF) were consistent with CO conversion trends. Lower TOF on the silica and titania supports were ascribed to metal support interactions resulting in coverage of cobalt crystallites with support moieties. Titania supported catalyst had the best selectivity (6.5% of CH 4 and 89% of C 5 + hydrocarbons). This is an abstract of a paper presented at the 2011 AIChE Annual Meeting (Minneapolis, MN 10/16-21/2011).