title: Mass-selected nanoparticles of PtxY as model catalysts for oxygen electroreduction.
abstract: Low-temperature fuel cells are limited by the oxygen reduction reaction, and their widespread implementation in automotive vehicles is hindered by the cost of platinum, currently the best-known catalyst for reducing oxygen in terms of both activity and stability. One solution is to decrease the amount of platinum required, for example by alloying, but without detrimentally affecting its properties. The alloy PtxY is known to be active and stable, but its synthesis in nanoparticulate form has proved challenging, which limits its further study. Herein we demonstrate the synthesis, characterization and catalyst testing of model PtxY nanoparticles prepared through the gas-aggregation technique. The catalysts reported here are highly active, with a mass activity of up to 3.05 A mgPt(-1) at 0.9 V versus a reversible hydrogen electrode. Using a variety of characterization techniques, we show that the enhanced activity of PtxY over elemental platinum results exclusively from a compressive strain exerted on the platinum surface atoms by the alloy core.
authors: Center for Individual Nanoparticle Functionality, Department of Physics, Technical University of Denmark, Kgs Lyngby DK-2800, Denmark.
authors: Patricia
authors: P
authors: Hernandez-Fernandez
authors: Center for Individual Nanoparticle Functionality, Department of Physics, Technical University of Denmark, Kgs Lyngby DK-2800, Denmark.
authors: Federico
authors: F
authors: Masini
authors: Center for Individual Nanoparticle Functionality, Department of Physics, Technical University of Denmark, Kgs Lyngby DK-2800, Denmark.
authors: David N
authors: DN
authors: McCarthy
authors: Center for Individual Nanoparticle Functionality, Department of Physics, Technical University of Denmark, Kgs Lyngby DK-2800, Denmark.
authors: Christian E
authors: CE
authors: Strebel
authors: SLAC National Accelerator Laboratory, 2575 Sand Hill Road, MS31, Menlo Park CA 94025, USA.
authors: Daniel
authors: D
authors: Friebel
authors: Center for Electron Nanoscopy, Technical University of Denmark, Kgs Lyngby DK-2800, Denmark.
authors: Davide
authors: D
authors: Deiana
authors: Center for Individual Nanoparticle Functionality, Department of Physics, Technical University of Denmark, Kgs Lyngby DK-2800, Denmark.
authors: Paolo
authors: P
authors: Malacrida
authors: Center for Individual Nanoparticle Functionality, Department of Physics, Technical University of Denmark, Kgs Lyngby DK-2800, Denmark.
authors: Anders
authors: 0000000178572752
authors: A
authors: Nierhoff
authors: Center for Individual Nanoparticle Functionality, Department of Physics, Technical University of Denmark, Kgs Lyngby DK-2800, Denmark.
authors: Anders
authors: A
authors: Bodin
authors: SLAC National Accelerator Laboratory, 2575 Sand Hill Road, MS31, Menlo Park CA 94025, USA.
authors: Anna M
authors: AM
authors: Wise
authors: Center for Individual Nanoparticle Functionality, Department of Physics, Technical University of Denmark, Kgs Lyngby DK-2800, Denmark.
authors: Jane H
authors: JH
authors: Nielsen
authors: Center for Electron Nanoscopy, Technical University of Denmark, Kgs Lyngby DK-2800, Denmark.
authors: Thomas W
authors: TW
authors: Hansen
authors: SLAC National Accelerator Laboratory, 2575 Sand Hill Road, MS31, Menlo Park CA 94025, USA.
authors: Anders
authors: A
authors: Nilsson
authors: Center for Individual Nanoparticle Functionality, Department of Physics, Technical University of Denmark, Kgs Lyngby DK-2800, Denmark.
authors: Ifan E L
authors: 000000032157492X
authors: IE
authors: Stephens
authors: Center for Individual Nanoparticle Functionality, Department of Physics, Technical University of Denmark, Kgs Lyngby DK-2800, Denmark.
authors: Ib
authors: I
authors: Chorkendorff
mesh_terms: D000497:Alloys / Q000737:chemistry; D002384:Catalysis; D004566:Electrodes; D005740:Gases / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry*; D010316:Particle Size; D010984:Platinum / Q000737:chemistry*
chemical_list: D000497:Alloys; D005740:Gases; D010984:Platinum; D010100:Oxygen