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arXiv · 1003.0035

Measuring individual overpotentials in an operating solid-oxide electrochemical cell

Farid El Gabaly·Michael Grass·Anthony H. McDaniel·Roger L. Farrow·Mark A. Linne·Zahid Hussain·Hendrik Bluhm·Zhi Liu·Kevin F. McCarty
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Abstract

We use photo-electrons as a non-contact probe to measure local electrical potentials in a solid-oxide electrochemical cell. We characterize the cell in operando at near-ambient pressure using spatially-resolved X-ray photoemission spectroscopy. The overpotentials at the interfaces between the Ni and Pt electrodes and the yttria-stabilized zirconia (YSZ) electrolyte are directly measured. The method is validated using electrochemical impedance spectroscopy. Using the overpotentials, which characterize the cell's inefficiencies, we compare without ambiguity the electro-catalytic efficiencies of Ni and Pt, finding that on Ni H_2O splitting proceeds more rapidly than H2 oxidation, while on Pt, H2 oxidation proceeds more rapidly than H2O splitting.

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Farid El Gabaly, Michael Grass, Anthony H. McDaniel, Roger L. Farrow, Mark A. Linne, Zahid Hussain, Hendrik Bluhm, Zhi Liu, Kevin F. McCarty. 2010-02-26. Measuring individual overpotentials in an operating solid-oxide electrochemical cell. https://doi.org/10.1039/c003581e

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