EMF measurements on mixed protonic/electronic conductors for hydrogen membrane applications

Henrik Karnøe Bentzer, Nikolaos Bonanos, John Phair

    Research output: Contribution to journalJournal articleResearchpeer-review

    Abstract

    Electromotive force (EMF) measurements are often used to estimate the transport number of conducting species in ionic and mixed conductors. In this work, the applicability of the method to systems, where both protonic, oxide-ionic and electronic conduction is significant, was examined. The effect of electrode polarisation resistance, water vapour concentration and impurities was analysed. Samples of SrCe0.95Y0.05O3 − δ were prepared and used in a number of EMF measurements, including wet and dry hydrogen and oxygen concentration cells. It was found that concentration cells including water vapour gave large errors in the determination of the oxide-ionic transport number, but gave good estimates of the protonic transport number. The protonic transport number was estimated to around 0.80 at 600 °C, decreasing to around 0.65 at 800 °C, consistent with previous investigations on similar materials.
    Original languageEnglish
    JournalSolid State Ionics
    Volume181
    Issue number3-4
    Pages (from-to)249-255
    ISSN0167-2738
    DOIs
    Publication statusPublished - 2010

    Keywords

    • Fuel Cells and hydrogen
    • Membranes

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