title: Palladium nanoparticles supported on vertically oriented reduced graphene oxide for methanol electro-oxidation.
abstract: Reduced graphene oxide (rGO) is a promising support material for nanosized electrocatalysts. However, the conventional stacking arrangement of rGO sheets confines the electrocatalysts between rGO layers, which decreases the number of catalytic sites substantially. We report here a facile synthesis of vertically oriented reduced graphene oxide (VrGO) through cyclic voltammetric electrolysis of graphene oxide (GO) in the presence of Na2 PdCl4 . Experiments without Pd nanoparticles or with a low loading amount of Pd nanoparticles results in the deposition of rGO parallel to the electrodes. The vertical orientation of Pd/rGO nanoflakes causes a remarkable enhancement of the catalytic activity toward methanol electro-oxidation. The mass activity (620.1 A gPd (-1) ) of Pd/VrGO is 1.9 and 6.2 times that of Pd/flat-lying rGO (331.8 A gPd (-1) ) and commercial Pd/C (100.5 A gPd (-1) ), respectively. Furthermore, the Pd/VrGO catalyst shows excellent resistance to CO poisoning. This work provides a simple wet-chemical method for VrGO preparation.
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082 (PR China).
authors.forename: Liming
authors.initials: L
authors.lastname: Yang
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Tang
authors.forename: Shenglian
authors.initials: S
authors.lastname: Luo
authors.forename: Chengbin
authors.initials: C
authors.lastname: Liu
authors.forename: Hejie
authors.initials: H
authors.lastname: Song
authors.forename: Dafeng
authors.initials: D
authors.lastname: Yan
mesh_terms: D002384:Catalysis; D055664:Electrochemical Techniques; D006108:Graphite / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D000432:Methanol / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D010084:Oxidation-Reduction; D010165:Palladium / Q000737:chemistry*
chemical_list: D010165:Palladium; D006108:Graphite; D000432:Methanol
keywords: electrochemistry; fuel cells; graphene; nanoparticles; palladium