Stabilizing effect of pseudo-dendritic polyethylenimine on platinum nanoparticles supported on carbon.

A new type of surfactant with a hydrophile of dendritic polyethylenimine (C(12)(EI)(7)) was synthesized by a cationic polymerization of dodecylamine with aziridine and was used as a stabilizer to prepare Pt colloid, which is then used in situ to prepare carbon-supported Pt nanoparticles. The effects of supporting carbon, surfactant concentration, and calcination time on the nanoparticle size and catalytic performance were determined from the transmission electron microscopic analyses and cyclic voltammograms. In the presence of carbon, the Pt particle size increased slightly with lower C(12)(EI)(7) content, while those with higher C(12)(EI)(7) concentrations remained unchanged.