Poly(diallyldimethylammonium chloride)-functionalized reduced graphene oxide supported palladium nanoparticles for enhanced methanol oxidation

Abstract

Poly(diallyldimethylammonium chloride, PDDA)-functionalized reduced graphene oxide (rGO) is explored as a catalyst support material for the first time. Pd nanoparticles are in situ deposited on rGO sheets due to electro-static attraction. Pd/rGO catalysts with nanometer particle size and high dispersion, are synthesized by a simple aqueous phase reduction method. The catalysts are characterized by field emission scanning electron microscopy, transmission electron microscopy, X-ray diffractometry and X-ray photoelectron spectroscopy, cyclic voltammetry and electrochemical impendence spectroscopy. The results indicate that Pd nanoparticles with an average size of 2.0 nm are uniformly dispersed on the graphene sheets. The prepared Pd/rGO catalyst displayed a dramatically higher electrochemical surface area, and higher and more stable activity towards methanol oxidation compared to commercial Pd/C in alkaline media, and is believed to be a promising catalyst for methanol-fed alkaline fuel cells.