Platinum nanoparticles assembled on different carbon materials and flower-like CeO2 for methanol electro-oxidation

The application of direct methanol fuel cells is hampered by not only low activity but also poor stability and CO tolerance of Pt catalyst. The electrocatalytic activity and stability of platinum nanoparticles assembled on different kinds of flower-like CeO2 (fCeO(2))/[Graphene (G), Carbon Vulcan (XC-72) and Ordered Mesoporous Carbon (CMK-3)] composite supports for methanol electro-oxidation were investigated. The catalyst samples were characterized by X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy, and X-ray photoelectron spectroscopic. The electrochemical properties of the catalysts were measured by a three electrode system on electrochemical workstation (IVIUM). The results show that the Pt grain size of Pt-fCeO(2)/G catalyst is the smallest. Compared with Pt-fCeO(2)/XC-72 and Pt-fCeO(2)/CMK-3, Pt-fCeO(2)/G has the lowest binding energies of Pt(0) and more hydroxyl, carbonyl, carboxyl and other oxygen-containing functional groups. This kind of oxygen-containing functional group can facilitate methanol oxidation and relieve CO poisoning. The mass-specific activity of Pt-fCeO(2)/G is 2.2 and 3.6 times higher than that of Pt-fCeO(2)/CMK-3 and Pt-fCeO(2)/XC-72, respectively. The activation energy of Pt-fCeO(2)/G catalyst for electrocatalytic oxidation methanol is the lowest, which is 16.63 kJ mol(-1). Pt-fCeO(2)/G appears to be a promising and cost effective methanol oxidation anode catalyst.