In this paper, we report the synthesis and characterization of nanoparticles of a PtxY alloy supported on a commercial mesoporous carbon with high mass and specific activity.

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The electrochemical behavior of C 60 -Pd polymer formed under electrochemical conditions and by the chemical synthesis was examined. In these polymers, fullerene moieties are covalently bonded to palladium atoms to form a polymeric network. Both materials deposited at the electrode surface show electrochemical activity at negative potentials due to the reduction of fullerene cage. Electrochemically formed thin polymeric films exhibit much more reversible voltammetric response in comparison to chemically synthesized polymers. The morphology and electrochemical behavior of chemically synthesized C 60 -Pd polymer depend on the composition of grown solution. Chemical polymerization results in formation of large, ca. 50 μm, crystallic superficial structures that are composed of regular spherical particles with a diameter of 150 nm. The capacitance properties of C 60 -Pd films were investigated by cyclic voltammetry and faradaic impedance spectroscopy. Specific capacitance of chemically formed films depends on the conditions of film formation. The best capacitance properties was obtained for films containing 1:3 fullerene to Pd molar ratio. For these films, specific capacitance of 35 Fg −1 was obtained in acetonitrile containing (n-C 4 H 9 ) 4 NClO 4 . This value is much lower in comparison to the specific capacitance of electrochemically formed C 60 -Pd film.

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Under well-controlled electrochemical conditions, C 60 -Pd polymer was deposited at the electrode surface in tetra-n-butylammonium acetonitrile/toluene solution. The electrochemical properties and conductivity of this material were studied in acetonitrile containing different tetraalkylammonium perchlorates as supporting electrolytes. The film exhibits n-doped properties. The electrochemical quartz crystal microbalance results reveal that the polymeric film is doped with cations of the supporting electrolyte during switching between the neutral and reduced states. Such a transition also results in a sharp increase of the film conductivity. The C 60 -Pd doping level and, therefore, charge carrier density depend on the size of the counterions incorporated into the polymeric structure during its reduction. The conductivity of the C 60 -Pd polymeric film also depends on the size of the doping cation. The negatively charged mobile carriers generated during the film reduction are responsible for the film conductivity. The charge propagation through the polymeric film can be quantitatively described by the electron-hopping model. The specific conductivity of C 60 -Pd and the electron diffusion coefficient are of the same order of magnitude as the values reported for typical p-doped conducting polymers. The conductivity properties of the composite of C 60 -Pd polymer and palladium nanoparticles were also investigated. Metallic nanoparticles participate in charge transport within the film in the potential range of the polymer neutral state. Therefore, the C 60 -Pd/Pd composite exhibits a large potential window of the conductivity state. The conductivity components related to the palladium nanoparticle involved in the charge transfer process and the electron hopping between differently charged fullerene centers were separated and determined.