CeO2 nanowires stretch-embedded in reduced graphite oxide nanocomposite support for Pt nanoparticles as potential electrocatalyst for methanol oxidation reaction. (10th August 2017)

• Record Type: Journal Article
• Authors: Wang, Haitao; Xue, Yu; Zhu, Baohui; Yang, Jingjing; Wang, Liang; Tan, Xiaoyao; Wang, Zhenbo; Chu, Yuanyuan
• Is Part Of: International journal of hydrogen energy. Volume 42:Number 32(2017)
• Page Start: 20549
• Page End: 20559
• Publication Date: 2017-08-10
• Subjects: Nanowire-sheet structure -- CeO2 nanowire -- Reduced graphite -- Metal-support interaction -- Methanol electro-oxidation; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2017.07.013
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: 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/RGO4 -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 Ce 4+ to Ce 3+ in CeO2 NWS will introduce oxygen vacancies and thus promote the tolerance of intermediate species in methanol oxidation. Graphical abstract: A novel nanowire-sheet hybrid RGO-CeO2 NWS has been synthesized and further regarded as support of Pt-based catalyst for methanol oxidation reaction (MOR). The Pt/GO-CeO2 NWS catalyst contains a micro-reactor with three contact-points among Pt, CeO2 and GO. The micro-reactor preserves the high conductivity facilitating transport of electrons to the catalyst surface and also plays bifunctional mechanism favoring methanol oxidation. The better catalytic performance may be owing to the following points that CeO2 NWS are anchored onto the chemical defects resulting in the restrain of the restack of graphene oxide at a certain extent and the changed valence state from Ce 4+ to Ce 3+ in CeO2 NWS will introduce oxygen vacancies and thus promote the tolerance of intermediate species methanol oxidation. Highlights: A novel nanowire-sheet hybrid RGO-CeO2 NWS has been synthesized. A high-effective catalytic region with three contact-points among Pt, CeO2 and GO. CeO2 NWS restrain the restack of graphene oxide to hinder the Pt embedded in folding. Oxygen vacancies in CeO2 NWS promote the tolerance of intermediate species during MOR.