Catalytic performance of several bifunctional cobalt-based catalysts in slurry-phase Fischer-Tropsch synthesis has been investigated at I MPa and 230 degrees C. The catalysts were prepared according to the conventional impregnation method using SiO2, Al2O3, montmorillonite (K10 (R)), and various zeolites (USY, ZSM-5 and MCM-22) as a support. When an acidic support was applied, the formation of heavier hydrocarbons was retarded and the carbon number distribution was shifted to gasoline range (C-4-C-12). Montmorillonite loaded with Co(Co/MONT) was a good catalyst, showing higher the CO conversion than Co/SiO2 and Co/Al2O3. MCM-22 exhibited a superior performance to other zeolitic supports. With decreasing aluminum content, the activity of CO/MCM-22 catalysts was remarkably enhanced and the selectivity to methane and isoparaffins decreased. Besides the high CO conversion (55-60%), C-4(+) isoparaffins were produced more selectively over Co/MCM-22 (43-53%) than Co/USY (43.5%) and Co/ZSM-5 (36%). Compared to the results under supercritical conditions, the slurry-phase conditions are more suitable for an active and selective production of gasoline-range hydrocarbons through the Fischer-Tropsch synthesis over MCM-22 supported Co catalysts. (c) 2006 Elsevier Ltd. All rights reserved.