CeO2-TiO2 was prepared by the sol-gel method, and Au was supported on CeO2-TiO2 by the deposition-precipitation (DP) method. The in-situ Fourier transform infrared spectroscopy (FT-IR), temperature-programmed reduction (TPR), X-ray diffraction (XRD) and N2 sorption were used to characterize the structure and the surface properties of catalyst. The results show that, the presence of CeO2 in TiO2 not only can increase its surface area and restrain the growth of TiO2 crystallites, but can also enhance the micro-strain of TiO2. Based on these effects, the interaction between gold crystallites and the TiO2 can be enhanced, resulting in a promotion of its oxidation capacity. The in-situ FT-IR spectra of CO adsorbed on the catalyst show that, the surface oxygen species of the catalyst can be changed by a reduction of surface at different temperatures, on which the function of various oxygen species for the CO oxidation was discussed.

Key words: Au catalyst, CO oxidation, CeO2-TiO2 support, surface oxygen species