Pt-Ru nanoparticles supported PAMAM dendrimer functionalized carbon nanofiber composite catalysts and their application to methanol oxidation

Polyamidoamine (PAMAM) dendrimers has been anchored on functionalized carbon nanofibers (CNF) and supported Pt-Ru nanoparticles have been prepared with NaBH4 as a reducing agent. The samples were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy (TEM) analysis. It was shown that Pt-Ru particles with small average size (2.6 nm) were uniformly dispersed on PAMAM/CNF composite support and displayed the characteristic diffraction peaks of Pt face-centered cubic structure. The electrocatalytic activities of the prepared-composites (20% Pt-Ru/PAMAM-CNF) were examined by using cyclic voltammetry for oxidation of methanol. The electrocatalytic activity of the CNF-based composite (20% Pt-Ru/PAMAM-CNF) electrode for methanol oxidation showed better performance than that of commercially available Johnson Mathey 20% Pt-Ru/C catalyst. The results imply that CNF-based PAMAM composite electrodes are excellent potential candidates for application in direct methanol fuel cells.