Shape control of exposed planes in ceria-zirconia based electrocatalysts for methanol oxidation

Abstract Nano CeO2–ZrO2 composites with different shapes are synthesized by using hydrothermal and deposition-precipitation methods, and used to obtain Pt/CeO2–ZrO2/RGO catalysts, where reduced graphene oxide(RGO) acts as a carrier. X-ray Diffrattometry (XRD), Raman spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy (XPS) detection methods are used to characterize morphology, phase composition, exposed planes and oxygen defects of the catalyst. The obtained CeO2–ZrO2 supports are in the form of nanorods, nanospheres, and nanocubes, which mainly expose (110), (111), and (100) planes, respectively. Electrocatalytic methanol oxidation tests onto the Pt/CeO2–ZrO2/RGO catalysts show that the electrochemically active surface area and the peak current density of nanorods are the largest ones among the three catalysts, reaching 61.4 m2/g and 230 A/g. In addition, the long-term discharge stability and CO poisoning resistance of the nanorod-shaped Pt/CeO2–ZrO2/RGO catalyst are the highest ones among the examined catalysts.