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

Abstract

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 (VO) 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 [VO] vs. OSC/SBET.