The effect of impregnation strategy on structural characters and CO2 methanation properties over MgO modified Ni/SiO2 catalysts

•MgO modified Ni/SiO2 catalysts were used for CO2 methanation.•Modified MgO enhanced adsorption and activation of CO2.•MgO addition inhibited NiO reduction.•MgO suppressed metallic Ni sintering and oxidation.

Mg-modified Ni/SiO2 catalysts with different MgO contents were prepared by two impregnation methods. The catalysts prepared by co-impregnation method could show better activity and stability than those prepared by sequential impregnation method. The modification of MgO acted as a key factor in enhancing the capacity of CO2 adsorption and accelerating the activation of CO2. Moreover, modified MgO could also increase Ni species dispersion and suppress the metallic Ni sintering and oxidation.

Graphical abstractMgO modification to Ni/SiO2 prepared by co-impregnation method leads to higher metallic Ni dispersion and enhanced ability for restraining metal sintering, keeping co-Ni–Mg/SiO2 catalysts stable.Figure optionsDownload full-size imageDownload as PowerPoint slide