Enhanced oxygen storage capacity of Ce0.88Mn0.12Oy compared to CeO2: An experimental and theoretical investigation

Abstract Ce 0.88 Mn 0.12 O y and CeO 2 nanoparticles have been successfully prepared via a supercritical antisolvent process. High-resolution transmission electron microscopy displays the hollow and spherical structures of these nanoparticles. X-ray diffraction analysis demonstrates the formation of Ce 0.88 Mn 0.12 O y solid solution. N 2 adsorption reveals that the Ce 0.88 Mn 0.12 O y has nearly the same surface area with the CeO 2 . It is shown that the Ce 0.88 Mn 0.12 O y has higher oxygen storage capacity (OSC) than the CeO 2 . To understand the mechanism of the improved OSC of the Mn doped CeO 2 , Raman spectroscopy, X-ray photoelectron spectra and density functional theoretical (DFT) calculations have been performed. It is found that the Ce 0.88 Mn 0.12 O y presents more oxygen vacancies, indicating the easier of oxygen mobility from bulk to surface. DFT calculations reveal that structural and electronic modifications are caused by the incorporation of Mn in the CeO 2 , resulting in activated oxygen species. The oxygen vacancy formation energy is lowered by the Mn doping. These changes are responsible for the enhanced OSC of the Ce 0.88 Mn 0.12 O y .