Electrochemical synthesis, characterization and electro-oxidation of methanol on platinum nanoparticles supported poly(o-phenylenediamine) nanotubes

The electrochemical synthesis and the characterization of Pt nanoparticles dispersed poly(o-phenylenediamine) (PoPD) nanotube electrodes, employing alumina membrane as templates are reported. The morphology of the electrodes was characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM) and transmission electron microscopy (TEM). Catalytic activity and stability for the oxidation of methanol were studied by using cyclic voltammetry and chronoamperometry. The results show that poly(o-phenylenediamine) nanotubes electrodes significantly enhance the catalytic activity of platinum nanoparticles for oxidation of methanol. The results obtained affirm that the dispersion of the platinum particles is connected with catalytic response to a higher activity. The chronoamperometric response confirms the better activity and stability of the nanotube-based electrode compared to the commercial 20 wt.% Pt/C (E-TEK) and template-free electrode. The nanotubular morphology of poly(o-phenylenediamine) helps in the effective dispersion of Pt particles facilitating the easier access of methanol to the catalytic sites. The poly(o-phenylenediamine) nanotubes modified with platinum nanoparticles cause a great increase in electroactivity and the electro-catalytic oxidation of methanol. (C) 2008 Elsevier B.V. All rights reserved.