It has been shown that Pt(3)Co nanoparticles used as a catalyst for cathode of Proton Exchange Membrane Fuel Cells (PEMFC) enhance oxygen reduction reaction (ORR) activity even by a factor of two compared to pure Pt nanoparticles. The local structure and chemical disorder of a commercially available Pt(3)Co nanocatalyst supported on high surface area carbon were investigated. High-quality XAFS spectra were collected at the ELETTRA synchrotron XAFS 11.1 beamline. XAFS spectra analysis have been performed accounting for the reduction of the coordination number and degeneracy of three-body configurations, resulting from transmission electron microscopy (TEM) and x-ray diffraction (XRD) extracted mean particles diameter, size distribution and expected surface atom contributions. The presence of a Co-Co first neighbour EXAFS signal is shown to be related to the degree of the alloy's chemical disorder. This is a good starting point for analyzing the atomic structure of Pt(3)Co nanocrystalline system and their changes as a function of alloy preparation or working conditions when they operate as a catalyst in PEMFC.

Study of the atomic structure and morphology of the Pt(3)Co nanocatalyst

MINICUCCI, Marco;DI CICCO, Andrea
2009-01-01

Abstract

It has been shown that Pt(3)Co nanoparticles used as a catalyst for cathode of Proton Exchange Membrane Fuel Cells (PEMFC) enhance oxygen reduction reaction (ORR) activity even by a factor of two compared to pure Pt nanoparticles. The local structure and chemical disorder of a commercially available Pt(3)Co nanocatalyst supported on high surface area carbon were investigated. High-quality XAFS spectra were collected at the ELETTRA synchrotron XAFS 11.1 beamline. XAFS spectra analysis have been performed accounting for the reduction of the coordination number and degeneracy of three-body configurations, resulting from transmission electron microscopy (TEM) and x-ray diffraction (XRD) extracted mean particles diameter, size distribution and expected surface atom contributions. The presence of a Co-Co first neighbour EXAFS signal is shown to be related to the degree of the alloy's chemical disorder. This is a good starting point for analyzing the atomic structure of Pt(3)Co nanocrystalline system and their changes as a function of alloy preparation or working conditions when they operate as a catalyst in PEMFC.
2009
275
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11581/237487
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