Methodology for Analysis of Solid Oxide Cells via Raman Spectroscopy

Abstract

Solid oxide cells (SOCs) are highly efficient electrochemical energy conversion devices capable of operating in both fuel cell and electrolysis modes. The operating temperatures of SOCs (500 – 800 °C, for IT-SOCs) create opportunities for direct utilisation of a wide variety of reactants, including low-grade fuels such as biogas, however, in-situ characterisation of evolving electrode morphologies and compositions is challenging. The design of an optically accessible experimental setup is presented alongside methodology for obtaining and interpreting in-situ Raman spectroscopic measurements. Raman spectroscopy is a valuable analytical tool for in operando monitoring of both solid oxide electrolysis (SOEC) and fuel cells (SOFC). Molecular species adsorbed on the surface can be identified, thus providing direct insight into reaction intermediates, material phase transformations and the presence of contaminants and poisons, such as carbon, chromium, sulphur and silica. Raman spectroscopic evidence of carbon deposition during CO2 electrolysis is discussed.

Improving the Efficiency of High-Temperature Electrolysis of Carbon Dioxide in a Solid Oxide Cell

“…As detailed in Table I Visual confirmation is the easiest method of determining successful plasma generation and requires a bespoke furnace which allows a sufficiently large field of vision to monitor the active area. Additionally, having visual access to the device and reaction zone allows for the implementation of a variety of spectroscopic methods such as IR (17,18,19) and Raman spectroscopy (18,20,21,22) in order to determine gas composition, materials composition, and adsorbed species in-operando. For these reasons, the reactor has been largely constructed from quartz tubing.…”