title: Vapor synthesis and thermal modification of supportless platinum-ruthenium nanotubes and application as methanol electrooxidation catalysts.
abstract: Metallic, mixed-phase, and alloyed bimetallic Pt-Ru nanotubes were synthesized by a novel route based on the sublimation of metal acetylacetonate precursors and their subsequent vapor deposition within anodic alumina templates. Nanotube architectures were tuned by thermal annealing treatments. As-synthesized nanotubes are composed of nanoparticulate, metallic platinum and hydrous ruthenium oxide whose respective thicknesses depend on the sample chemical composition. The Pt-decorated, hydrous Ru oxide nanotubes may be thermally annealed to promote a series of chemical and physical changes to the nanotube structures, including alloy formation, crystallite growth, and morphological evolution. Annealed Pt-Ru alloy nanotubes and their as-synthesized analogs demonstrate relatively high specific activities for the oxidation of methanol. As-synthesized, mixed-phase Pt-Ru nanotubes (0.39 mA/cm(2)) and metallic alloyed Pt64Ru36NTs (0.33 mA/cm(2)) have considerably higher area-normalized activities than PtRu black (0.22 mA/cm(2)) at 0.65 V vs RHE.
authors.affiliation: †Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Atkinson
authors.forename: Raymond R
authors.initials: RR
authors.lastname: Unocic
authors.forename: Kinga A
authors.initials: KA
authors.lastname: Unocic
authors.forename: Gabriel M
authors.initials: GM
authors.lastname: Veith
authors.affiliation: †Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States.
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Zawodzinski
authors.affiliation: †Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States.
authors.forename: Alexander B
authors.initials: AB
authors.lastname: Papandrew
keywords: alloy; anodic alumina; chemical vapor deposition; electrocatalysts; extended surface catalysts; fuel cell; nanotubes; template