Ni/CeO2 catalysts with high CO2 methanation activity and high CH4 selectivity at low temperatures

CO2 methanation was performed over 10 wt%Ni/CeO2, 10 wt%Ni/α-Al2O3, 10 wt%Ni/TiO2, and 10 wt%Ni/MgO, and the effect of support materials on CO2 conversion and CH4 selectivity was examined. Catalysts were prepared by a wet impregnation method, and characterized by BET, XRD, H2-TPR and CO2-TPD. Ni/CeO2 showed high CO2 conversion especially at low temperatures compared to Ni/α-Al2O3, and the selectivity to CH4 was very close to 1. The surface coverage by CO2-derived species on CeO2 surface and the partial reduction of CeO2 surface could result in the high CO2 conversion over Ni/CeO2. In addition, superior CO methanation activity over Ni/CeO2 led to the high CH4 selectivity.

▶ Ni/CeO2 showed a high CO2 conversion close to the equilibrium one from 300 °C. ▶ A large CO2 adsorption on Ni/CeO2 led to high CO2 conversion at low temperatures. ▶ CO methanation was improved over Ni/CeO2 compared to Ni/α-Al2O3. ▶ Excellent activity of CO methanation over Ni/CeO2 resulted in high CH4 selectivity.