Novel Mesoporous and Multilayered Yb/N-Co-Doped CeO₂ with Enhanced Oxygen Storage Capacity

A cubic fluorite-type CeO₂ with mesoporous multilayered morphology was synthesized by the solvothermal method followed by calcination in air, and its oxygen storage capacity (OSC) was quantified by the amount of O₂ consumption per gram of CeO₂ based on hydrogen temperature programmed reduction (H₂-TPR) measurements. Doping CeO₂ with ytterbium (Yb) and nitrogen (N) ions proved to be an effective route to improving its OSC in this work. The OSC of undoped CeO₂ was 0.115 mmol O₂/g and reached as high as 0.222 mmol O₂/g upon the addition of 5 mol.% Yb(NO₃)₃∙5H₂O, further enhanced to 0.274 mmol O₂/g with the introduction of 20 mol.% triethanolamine. Both the introductions of Yb cations and N anions into the CeO₂ lattice were conducive to the formation of more non-stoichiometric oxygen vacancy (V_O) defects and reducible-reoxidizable Ceⁿ⁺ ions. To determine the structure performance relationships, the partial least squares method was employed to construct two linear functions for the doping level vs. lattice parameter and [V_O] vs. OSC/S_BET.