title: Preparation and catalytic activity of Au-Pd, Au-Pt, and Pt-Pd binary metal dendrimer nanocomposites.
abstract: Catalytic activity of Au-Pt, Au-Pd, and Pt-Pd dendrimer nanocomposites for reduction of p-nitrophenol was investigated in water. The bimetallic dendrimer nanocomposites were prepared by simultaneous reduction with sodium borohydride in the presence of poly(amidoamine) (PAMAM) dendrimers with amine and carboxyl terminal groups. Average diameters of the obtained particles were 2-4 nm by transmission electron microscopy. From UV-vis spectroscopy, it was found that the particles were not mixtures of monometallic particles but binary ones. X-ray photoelectron spectroscopy showed that formation of binary composite particles prevents palladium atoms from oxidation. The Au-Pd and Pt-Pd binary particles exhibited higher catalytic activity than monometallic ones. On the other hand, catalytic activity of Au-Pt binary particle was comparable to that of platinum nanoparticles.
authors.affiliation: Department of Applied Chemistry, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Endo
authors.forename: Takehito
authors.initials: T
authors.lastname: Kuno
authors.forename: Tomokazu
authors.initials: T
authors.lastname: Yoshimura
authors.forename: Kunio
authors.initials: K
authors.lastname: Esumi
mesh_terms: D001894:Borohydrides / Q000737:chemistry; D002384:Catalysis; D050091:Dendrimers; D006046:Gold / Q000737:chemistry*; D008422:Materials Testing; D008670:Metals / Q000737:chemistry; D046529:Microscopy, Electron, Transmission; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D009596:Nitrophenols / Q000737:chemistry; D010100:Oxygen / Q000378:metabolism; D010165:Palladium / Q000737:chemistry*; D010984:Platinum / Q000737:chemistry*; D011073:Polyamines / Q000737:chemistry; D013499:Surface Properties; D013997:Time Factors; D014466:Ultraviolet Rays
chemical_list: D001894:Borohydrides; D050091:Dendrimers; D008670:Metals; D009596:Nitrophenols; C104700:PAMAM Starburst; D011073:Polyamines; D010984:Platinum; D010165:Palladium; D006046:Gold; C025364:sodium borohydride; D010100:Oxygen; C024836:4-nitrophenol