The high increase of atmospheric CO2 concentration has been received a great deal of public attention in recent decades. In order to reduce the atmospheric carbon footprint, several feasible promising processes have been developing. One of them is the CO2 utilization concept in which CO2 is likely to play a role as the initial carbon source. The power-to-gas (P2G) in which CO2 is converted into methane through methanation is the representative concept. Cobalt metal has been known as the most active component not only for Fischer – Tropsch reaction but also for methanation. Therefore, cobalt was chosen as an active component and the two preparation methods such as co–precipitation and wet impregnation were compared in this study to develop the active cobalt–based catalysts for both CO and CO2 methanation. Furthermore, the effect of the pretreatment conditions especially calcination temperature on the catalytic activity was also examined. In the case of Co-CeO2 catalyst prepared with a co-precipitation method, the catalyst calcined at 500 ℃ showed the better catalytic performance than those calcined at 300 or 700 ℃. In the case of Co-ZrO2 catalyst prepared with a co-precipitation method, the catalyst calcined at 700 ℃ exhibited the better catalytic activity than those calcined at 500 or 800 ℃. Among the tested supports such as CeO2, ZrO2 and SiO2, ceria was proven as the best support. The co-precipitated method appears to be better than the wet impregnation one for ceria- and zirconia-supported cobalt catalysts. The catalytic activity appears to be closely related to the catalytically active surface area (CASA), surface basicity of the support and interaction between the cobalt metal and the support.
