Synergic CO oxidation activities of boron-CeO2 hybrid materials prepared by dry and wet milling methods

Boron-CeO2 hybrid materials were prepared by dry and wet ball-milling methods and characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), FT-IR and X-ray photoelectron spectroscopy (XPS). We also demonstrated CO oxidation activity of the material using temperature-programmed reaction mass spectrometry, and found an interesting synergic effect of CO oxidation in response to hybridization of boron and CeO2. The oxidation state of Ce was found to have changed from +4 to +3 during the milling process, which was confirmed by the Ce 3d XPS scan result. These findings indicate that boron maintains the convertible oxidation states (Ce3+↔Ce4+) of Ce at the interface between boron and CeO2 during the CO oxidation reaction. The present study highlights the potential application of boron and CeO2 hybrid materials to pollution control, chemical industry and propulsion energy sources.