title: Enhanced electrocatalytic performance of processed, ultrathin, supported Pd-Pt core-shell nanowire catalysts for the oxygen reduction reaction.
abstract: We report on the synthesis, characterization, and electrochemical performance of novel, ultrathin Pt monolayer shell-Pd nanowire core catalysts. Initially, ultrathin Pd nanowires with diameters of 2.0 ± 0.5 nm were generated, and a method has been developed to achieve highly uniform distributions of these catalysts onto the Vulcan XC-72 carbon support. As-prepared wires are activated by the use of two distinctive treatment protocols followed by selective CO adsorption in order to selectively remove undesirable organic residues. Subsequently, the desired nanowire core-Pt monolayer shell motif was reliably achieved by Cu underpotential deposition followed by galvanic displacement of the Cu adatoms. The surface area and mass activity of the acid and ozone-treated nanowires were assessed, and the ozone-treated nanowires were found to maintain outstanding area and mass specific activities of 0.77 mA/cm(2) and 1.83 A/mg(Pt), respectively, which were significantly enhanced as compared with conventional commercial Pt nanoparticles, core-shell nanoparticles, and acid-treated nanowires. The ozone-treated nanowires also maintained excellent electrochemical durability under accelerated half-cell testing, and it was found that the area-specific activity increased by ~1.5 fold after a simulated catalyst lifetime.
authors.affiliation: Department of Chemistry, State University of New York at Stony Brook, Stony Brook, New York 11794-3400, USA.
authors.forename: Christopher
authors.initials: C
authors.lastname: Koenigsmann
authors.forename: Alexander C
authors.initials: AC
authors.lastname: Santulli
authors.forename: Kuanping
authors.initials: K
authors.lastname: Gong
authors.forename: Miomir B
authors.initials: MB
authors.lastname: Vukmirovic
authors.forename: Wei-ping
authors.initials: WP
authors.lastname: Zhou
authors.forename: Eli
authors.initials: E
authors.lastname: Sutter
authors.forename: Stanislaus S
authors.initials: SS
authors.lastname: Wong
authors.forename: Radoslav R
authors.initials: RR
authors.lastname: Adzic