摘要 : Polyelectrolyte-stabilized Pt nanoparticles were synthesized by ethanol reduction of Pt salt (H2PtCl6) in the presence of ionic polyelectrolyes such as poly(diallyldimethylammonium chloride) (PDDA), poly(allylamine hydrochloride) ... 展开 Polyelectrolyte-stabilized Pt nanoparticles were synthesized by ethanol reduction of Pt salt (H2PtCl6) in the presence of ionic polyelectrolyes such as poly(diallyldimethylammonium chloride) (PDDA), poly(allylamine hydrochloride) (PAH), poly(sodium 4-styrenesulfonate) (PSS), Nafion, poly(acrylic acid) (PAA), poly(2-acrylamido-2-methyl-l-propanesulfonic acid) (PAMP) and non-ionic polymer, poly(vinylpyrrolidone) (PVP). The formation, size and distribution of polyelectrolyte-stabilized Pt nanoparticles (Pt NPs) were characterized by UV-vis absorption spectrum and transmission electron microscopy (TEM). Polyelectrolyte-stabilized Pt NPs have a particle size range of 2-4 nm, however, they show significantly different electrochemical activities for the methanol oxidation and oxygen reduction reactions. The best electrocatalytic activities were observed on PDDA-Pt and PSS-Pt NPs which also showed better electrocatalytic activity than that of the commercial Pt black catalysts. The results indicate the significant enhancing effect of the NH4+ and SO3- end groups of the polyelectrolytes on the electrocatalytic activities of Pt NPs for polymer electrolyte membrane fuel cells. (C) 2007 Elsevier B.V. All rights reserved. 收起