Shape and size stability of Pt nanoparticles for MeOH electro-oxidation

Pt nanoparticles (NPs) of different shape (cubic and octahedral/tetrahedral) and size (5–10 nm) were synthesized by one-step polyol-based synthetic procedures that permit the concomitant control of the shape and size. The shape and size stability of these particles under repetitive methanol (MeOH) electro-oxidation cycles was investigated by transmission electron microscopy (TEM) as well as cyclic voltammetry (CV). The TEM images of the particles taken before and after being subject to 1000 MeOH electro-oxidation CV cycling and the corresponding hydrogen adsorption/desorption profile in the CVs indicated that, the octahedral/tetrahedral Pt NPs had the highest stability among the samples investigated. Infra-red measurements suggest that this observation may be a result of exceptionally strong interaction of the capping polymer with octa/tetrahedral Pt NPs. These findings indicate that the synthetic procedure employed in this study can be used to synthesize highly stable catalyst particles with tunable shape and size.