Zr-doped CeO2 nanorods as versatile catalyst in the epoxidation of styrene with tert-butyl hydroperoxide as the oxidant

Abstract

The CeO2 nanorods with various Zr dopant concentrations were studied in terms of their activity in the selective oxidation of styrene to styrene oxide using tert–butyl hydroperoxide as the oxidant. Several techniques were used to characterize the synthesized Zr-doped CeO2 nanorods. The results indicated that Zr ions were doped into the ceria lattice and formed fluorite-like solid solutions, resulting in an increase in oxygen vacancy concentration. It was also found that Zr content has a significant impact on intrinsic natures of the catalyst, namely, the specific surface area, oxygen vacancy concentration and the content of Ce3+ ions, which were found to determine the catalytic efficiency of the catalyst in the epoxidation of styrene. It is interesting that the remarkably increased catalytic performance of the ceria nanorods with 10mol% zirconium is mainly attributed to the more oxygen vacancy and the higher percentage of Ce3+. Furthermore, recycling studies proved the heterogeneous zirconium-doped ceria nanorods did not lose the initial high catalytic activity after five successive recycles.