In situ XAS of Pt monolayer model fuel cell catalysts: balance of na-nostructure and bimetallic interactions

ORAL

Abstract

The mechanism of the electrochemical oxygen reduction reaction (ORR) has been well understood based on DFT calculations, but there has been a lack of supporting experimental data, due to the difficulties of probing the electrocatalyst surface in situ. Our new approach using Pt monolayer model catalysts provides true surface sensitivity for - originally bulk sensitive - x-ray absorption spectroscopy (XAS) and, owing to the high resolution of the Bragg analyzer at SSRL beamline 6-2, allows for in situ detection of chemisorbed O and OH, whose stability can be used as a descriptor in predicting the activity of new ORR catalyst materials. Our ability to control the growth mode in the Pt/Rh(111) model system allows us to generate Pt nanostructures with highly different O affinities from identical starting materials.

*This work was funded by the Department of Energy, Office of Basic Energy Sciences.

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Authors

  • Daniel Friebel

    • SLAC National Accelerator Laboratory

  • Venkat Viswanathan

    • SUNCAT Center for Interface Science and Catalysis

  • Ask Larsen

    • CAMD, Technical University of Denmark

  • Daniel J. Miller

    • SLAC National Accelerator Laboratory

  • Hirohito Ogasawara

    • SLAC National Accelerator Laboratory

  • Toyli Anniyev

    • None

  • Christopher P. O'Grady

    • SUNCAT Center for Interface Science and Catalysis

  • Jens N{\O}rskov

    • SUNCAT Center for Interface Science and Catalysis

  • Anders Nilsson

    • SLAC National Accelerator Laboratory