Optimization of Cobalt Loading in Co-CeO2 Catalyst for the High Temperature Water-Gas Shift Reaction

We varied the cobalt loading (10, 15, 25, 35 wt%) to determine the optimum loading in a Co-CeO2 catalytic system used for the high temperature water-gas shift (WGS) reaction. Severe reaction conditions were used to compare the catalytic performances including a very high gas hourly space velocity (142,663 h(-1)) and a high CO concentration (similar to 38%). Among the prepared catalysts, 15% Co-CeO2 exhibited excellent catalytic activity in the temperature range of 350-550 degrees C without promoting the methanation reaction. In addition, this catalyst showed relatively stable activity for 50 h at 400 degrees C. The outstanding performance of 15% Co-CeO2 catalyst is mainly due to the highest amount of dispersed cobalt atoms on the catalyst surface. Additionally, the WGS activity was affected by the oxygen vacancy concentration.