In-Situ Characterization of Electrode Reactions in Solid Oxide Fuel Cells

Abstract

We have designed and constructed a state-of-the-art system capable of simultaneously performing in-situ FTIR spectroscopy, Raman spectromicroscopy, and impedance spectroscopy on a solid oxide fuel cell (SOFC) under practical operating conditions while the gas composition is monitored in real time by mass spectrometry. Raman spectromicroscopy, in particular, offers capabilities for not only probing surface species on an electrode but also mapping where a specific reaction of interest is taking place on the electrode. Furthermore, both surface reaction kinetics and bulk properties of electrode materials may be deduced from the time dependence of in-situ vibrational spectra collected during transition from one equilibrium state to another. When applied to an SOFC with patterned electrodes perturbed by an electrical, chemical, or optical stimulus, these techniques become even more powerful in investigating active reaction sites and bulk properties of various electrode materials, providing invaluable information that has never before been accessible.