CeO2 nanowires stretch-embedded in reduced graphite oxide nanocornposite support for Pt nanoparticles as potential electrocatalyst for methanol oxidation reaction

A novel hybrid composite RGO-CeO2 Nws with the nanowire-sheet structure was synthesized by a facile hydrothermal process using ethanol/water as the solvent without any organic additives. The graphene oxide proceeds to reduce to graphene and chemical bonds form between graphene oxide and CeO2 NWS. Pt-based catalysts with the RGO-CeO2 NWS composite as the support were then prepared by a microwave-assisted polyol process. The resultant catalysts were characterized by X-ray diffraction, Raman spectroscopy, Scanning tunneling microscopy, X-ray photoelectron spectroscopy, High resolution transmission electron microscopy and electrochemical tests. The results show that the hybrid Pt/RGO(4)-CeO2 Nws exhibits the best catalytic activity and the increased catalytic efficiency of Pt in the hybrid catalysts is evidence that CeO2 NWS are anchored onto the chemical defects in the wrinkles and edges of the graphene surface. This avoids the restacking of graphene oxide, thus hindering the Pt nanoparticles embedded in folding and increasing the exposed active sites. The changed valence state from Ce4+ to Ce3+ in CeO2 Nws will introduce oxygen vacancies and thus promote the tolerance of intermediate species in methanol oxidation. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.