Effects of loadingtransition metal (Mn, Cr,Fe, Cu) oxides on CeO2-ZrO2solid solution to oxygen storage/release properties

Abstract Cerium zirconium-based (CZ)oxygen storage materials (OSMs) play a crucial role in three-way catalysts (TWCs), while CZ need to be modified to satisfy more rigorous emission standard. Inthisstudy, transition metal (TMs=Mn, Cr, Fe, Cu) oxides modified CZ were prepared byincipient wetness impregnation method to improve the oxygen storage capacity of CZ-based materials.To clearly illustrate the influence of TM oxides, N2 adsorption-desorption, X-ray diffraction (XRD), oxygen storage capacity(OSC), Temperature programmed reduction by H2 (H2-TPR) and X-ray photoelectron spectroscopy (XPS) were used to characterize the physical and chemical properties of samples. It was found that, all of modified CZhave higher OSC, lower reduction temperatures than that of pristine CZ. Interaction between TMOs and CZ take precedence over specific surface to influence OSC.Notably, FeOx/CZ has the highest OSC, which isabout 1.9 times of CZ and itcould be attributed tosynergistic effect between FeOx and CZ;CuOx/CZ has the lowest reduction temperature which is 168°Clowerthan that ofCZ, and it can be explained by hydrogen spillover effect.