title: Supported Pd-Cu bimetallic nanoparticles that have high activity for the electrochemical oxidation of methanol.
abstract: Monodisperse bimetallic Pd-Cu nanoparticles with controllable size and composition were synthesized by a one-step multiphase ethylene glycol (EG) method. Adjusting the stoichiometric ratio of the Pd and Cu precursors afforded nanoparticles with different compositions, such as Pd(85)-Cu(15), Pd(56)-Cu(44), and Pd(39)-Cu(61). The nanoparticles were separated from the solution mixture by extraction with non-polar solvents, such as n-hexane. Monodisperse bimetallic Pd-Cu nanoparticles with narrow size-distribution were obtained without the need for a size-selection process. Capping ligands that were bound to the surface of the particles were removed through heat treatment when the as-prepared nanoparticles were loaded onto a Vulcan XC-72 carbon support. Supported bimetallic Pd-Cu nanoparticles showed enhanced electrocatalytic activity towards methanol oxidation compared with supported Pd nanoparticles that were fabricated according to the same EG method. For a bimetallic Pd-Cu catalyst that contained 15 % Cu, the activity was even comparable to the state-of-the-art commercially available Pt/C catalysts. A STEM-HAADF study indicated that the formation of random solid-solution alloy structures in the bimetallic Pd(85)-Cu(15)/C catalysts played a key role in improving the electrochemical activity.
authors.affiliation: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, The Chinese Academy of Sciences, Dalian 116023, PR China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Yin
authors.forename: Wu
authors.initials: W
authors.lastname: Zhou
authors.forename: Yongjun
authors.initials: Y
authors.lastname: Gao
authors.forename: Ding
authors.initials: D
authors.lastname: Ma
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Kiely
authors.forename: Xinhe
authors.initials: X
authors.lastname: Bao