Study of doped mesoporous ceria with tailored oxygen vacancies for enhances activity for ethylbenzene oxidation application

Abstract

Herein, we present a ligand-assist induction self-assembly method to prepare mesoporous CeO2 (mCeO2) nanospheres. Then, a series of mCeO2 catalysts with Ni or Co ions doped with various Ce/Ni (Co) ratios were prepared by this method. These mCeO2:xNi/Co (mCeO2 with different mound Ni or Co ions doping) samples were studied using a range of characterization techniques (XRD, N2 adsorption-desorption, SEM, TEM, XPS, H2-TPR, O2-TPD and Raman spectroscopy). Both mCeO2 and mCeO2:xNi/Co nanospheres show high surface areas. XPS spectra reveal that the ratios of Ce3+/Ce4+ increase as the doping concentration of Ni/Co ions increasing, which indicated that mCeO2:xNi/Co samples are more reducible than pure mCeO2. The H2-TPR, O2-TPD, and Raman analysis results reveal that the doping of Ni or Co ions significantly increased the concentration of surface oxygen vacancies in mCeO2. As for ethylbenzene oxidation reaction, doping-mesoporous ceria catalysts exhibited a superior catalytic activity when compared to pure mesoporous ceria catalysts prepared by the same method.