Origin of doping effects on the oxygen storage capacity of Ce1 − xMxO2 (M = Fe, Ru, Os, Sm, Pu)

We have used density functional theory with on-site Coulomb interactions (DFT + U) to study the origin of doping effects on the oxygen storage capacity (OSC) of Ce1 − xMxO2 (M = Fe, Ru, Os, Sm, Pu). Substitution of M (M = Fe, Ru, Os, Sm, Pu) in CeO2 results in activated oxygen in Ce1 − xMxO2 compared to pure CeO2 due to its structural and electronic modifications. It is found that the oxygen vacancy formation energy is lowered by doping noble metals. These results are crucial for understanding the doping effects on the OSC of ceria-based materials in heterogeneous catalysis.

93Research highlights► The origin of doping effects on the oxygen storage capacity of Ce1 − xMxO2 (M = Fe, Ru, Os, Sm, Pu) have been studied by the DFT + U method. ► Doping of CeO2 with noble metals gives rise to higher oxygen storage capacity. ► The oxygen vacancy formation energy is lowered by doping of CeO2 with noble metals. The interaction energy (Eint) and relaxation energy (Erel) may be considered as convenient parameters when screening for an appropriate metal doped CeO2 materials.