Thermochemical CO2 splitting reaction with CexM1−xO2−δ (M=Ti4+, Sn4+, Hf4+, Zr4+, La3+, Y3+ and Sm3+) solid solutions

•Doping of tetravalent cations into CeO2 improves the O2 evolution activity.•Doping of tetravalent cations into CeO2 improves the CO production.•The estimated activation energies for the reduction step was calculated.•The kinetic models for CO generation reaction was given.•One step thermochemical CO2 splitting reaction was discovered. This study deals with doping of CeO2 with different cations M (M=Ti4+, Sn4+, Hf4+, Zr4+, La3+, Y3+ and Sm3+) to improve the reaction activity in two step thermochemical CO2 splitting reaction. The results show that the addition of tetravalent cations M (M=Ti4+, Sn4+, Hf4+ and Zr4+) into CeO2 significantly enhances the O2 evolution activity. The O2 production at 1400°C increases as follows: CeO2 (2.5ml/g)