Synthesis and characterization of CoPt nanoparticles prepared by room temperature chemical reduction with PAMAM dendrimer as template.

We describe an approach to synthesize monodisperse CoPt nanoparticles with dendrimer as template by a simple chemical reduction method in aqueous solution using NaBH4 as reducing agent at room temperature. The as-made CoPt nanoparticles buried in the dendrimer matrix have the chemically disordered fcc structure and can be transformed to the fct phase after annealing at 700 degrees C. This is the first report of dendrimer-mediated room temperature synthesis of monodisperse magnetic nanoparticles in aqueous solution.

Synthesis and characterization of PtRe alloy nanoparticles as electrocatalysts for methanol oxidation.

We report a new synthesis of PtRe alloy nanoparticles (NPs) and their electrocatalytic activity for methanol oxidation. PtRe alloy NPs with controlled composition were prepared by a capping agents-based colloidal method. In the synthesis, trioctylamine was used as high-boiling solvent, and oleylamine/oleic acid were employed as capping agents to control the particle size and dispersion. The PtRe NPs were fully characterized by TEM, EDX, XRD and XPS. The as-prepared PtRe NPs had a narrow size distribution, and displayed a good dispersion in hydrocarbon solvents. Carbon-supported PtRe catalysts were prepared by physical deposition of as-prepared particles on carbon powder, followed by the catalytic activation at 400 degrees C in Ar/H2. Electrochemical studies showed the PtRe catalysts had high activity for methanol electrooxidation.