Activity improvement of Pt/C catalysts by adding CeO2 nanoparticles

Carbon-supported platinum catalysts were prepared by NaBH4 reduction of metal precursors and the CeO2 nanoparticles were prepared by citric acid sol-gel method. The structure and morphology of two kinds of nanoparticles were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. The Pt particles were uniformly dispersed on the carbon surface and showed the rod-like morphology. The CeO2 was spherical in shape. The appropriate amount of CeO2 nanoparticles was added into Pt/C systems to improve activity of the catalysts. Several electrochemical techniques such as cyclic voltammogram (CV), chronoamperometry (I-t) and electrochemical impedance spectroscopy (EIS) were used to investigate the properties of CeO2-Pt/C catalysts for methanol electrooxidation in 1 mol/L CH3OH+0.5H2SO4 aqueous solutions. The results revealed that compared with Pt/C catalysts CeO2-Pt/C exhibited a higher activity and stability for methanol electro-oxidation. Moreover, the effect of CeO2 content on the activity of Pt/C catalysts was discussed in detail.