The effect of doping traditional Co-Mo/Al2O3 catalysts with Ce and K on their catalytic activity for the water gas shift reaction in coke oven gas was investigated. Doped Co-Mo/Al2O3 catalysts were prepared by adding different amounts of Ce and K (CeO2, K2O, and CeO2-K2O similar to 10 wt%) by a wetness impregnation method and characterized by BET specific surface area measurements and scanning electron microscopy (SEM). The characterization results reveal that CeO2 addition mainly produced an electronic effect and aided to disperse the active ingredient. At the same time, the synergistic effect between Ce and K contributed to the catalytic activity. Activity tests showed that Ce-K-promoted Co-Mo/Al2O3 catalysts exhibited greater activity and selectivity than Co-Mo-Ce/Al2O3 catalysts and Co-Mo-K/Al2O3 catalysts. The maximum promotion of the water gas shift reaction was observed when 3.0 wt% CeO2 and 6.0 wt% K2O were added. Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.