Attention has been increasingly paid to the partial oxidation of lower alkanes to synthesis gas, due to its intrinsic energy saving process. We studied the partial oxidation of ethane (POE) on Co loaded on various supports. The POE performance varied as follows: Y2O3, CeO2, ZrO2, La2O3 >> SiO2, Al2O3, TiO2 > MgO. Comparing Y2O3 and CeO2, the carbon deposition during the POE was nealigible on CeO2 and therefore CeO2 was the most preferable support. By changing space velocity and O-2 partial pressure, reaction mechanism of POE was studied and it was revealed that two-step mechanism was prevailing; combustion of ethane to H2O and CO2 and subsequent reforming of ethane with H2O and CO2 to synthesis gas. Co/CeO2 catalyst exhibited high and stable catalytic activity for 10 h; high ethane conversion of 18% (maximum ethane conversion 20% at O-2/C2H6 = 0.2) with H-2 and CO selectivities of 93 and 84%, respectively. (c) 2005 Elsevier B.V. All rights reserved.