Synthesis and characterization of polyhedral and quasi-sphere non-polyhedral Pt nanoparticles: Effects of their various surface morphologies and sizes on electrocatalytic activity for fuel cell applications

In this article, polyhedral and non-polyhedral Pt nanoparticles were prepared by modified polyol method using AgNO₃ as a good structure-modifying agent. Their TEM and HRTEM images showed the particle size in the range of 8-16 nm for both the above cases. The structures and properties of the surfaces of Pt nanoparticles were investigated through cyclic voltammetry in dilute perchloric acid (HClO₄) electrolyte solution. A comparison of the electrocatalytic property in methanol electrooxidation was made. Here, the effects of polyhedral and non-polyhedral morphologies on their catalytic properties were studied. The results revealed that the special catalytic activity of quasi-sphere non-polyhedral Pt nanoparticles is higher than that of polyhedral Pt nanoparticles. In addition, Pt nanoparticles of un-sharp and quasi-sphere morphologies exhibit the tolerance to poisoning species better than that of Pt nanoparticles of sharp and polyhedral morphologies due to the various morphologies of the catalyst surfaces in the chronoamperometric plots. Therefore, these experimental evidences showed the morphology-dependent catalytic property according to the various morphologies and complexity of their catalyst surfaces.