The effect of heat treatment on the performance of the Ni/(Zr-Sm oxide) catalysts for carbon dioxide methanation

► CO2 methanation on the catalyst prepared from an aqueous ZrO2 sol with Sm(NO3)3 and Ni(NO3)2. ► Rapid methanation with almost 100% methane selectivity and no CO formation. ► The active catalyst is Ni supported on tetragonal ZrO2 stabilized by inclusion of Sm3+. ► The activity increase with Sm3+ content, that is, oxygen vacancies in tetragonal ZrO2 lattice.