Surface Structure and Electrochemical Properties of MoO3/CeO2 Composite Catalysts by Hydrothermal Method

A series of molybdic oxide/ceria (MoO3/CeO2) composite catalysts with different MoO3 concentrations (0, 5wt%, 7.5wt%, 10wt%, 12.5wt%, 15wt% and 20wt%) were prepared by hydrolysis of ammonium molybdate and the supports of CeO2 at 70 The crystal structure, themorphology and interaction between MoO3 and CeO2 on the surface of the prepared MoO3/CeO2 composite catalysts were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscope (FT-IR), X-ray photoelectron spectrometer (XPS), scanning electron microscope (SEM) and energy dispersive spectrometer (EDS), respectively. The catalytic activities of the prepared catalysts were evaluated by the electrolysis sulfuric acid solution. Results show that the catalytic activity of MoO3/CeO2 composite catalysts are superior compared with that of pure CeO2, and the optimal concentration of MoO3 is12.5wt%. The MoO3 content threshold value of composite catalysts is between 12.5wt% and 15wt%, and it is identified that the Mo-O-Ce bond forms at the interface of MoO3 and CeO2 in the composite catalysts. Moreover, more surface Mo-O-Ce bond over the MoO3/CeO2 composite catalysts will further benefit the improvement of the catalytic activity.