In-Situ Analysis of Co-Electrolysis Species Via Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS)

Syngas production through co-electrolysis of steam and carbon dioxide has been shown as an effective method of CO₂ utilisation, however little is known about the complex surface reaction mechanisms involved.  Further understanding is needed in order to optimise SOC operation parameters and inform materials development.  Currently many investigative techniques are ex-situ, some of which are even destructive: e.g. SEM imagining of the microstructure.  To fully understand reaction intermediates, characterise electrochemical performance, and develop novel materials and microstructures for co-electrolysis SOCs; in-situ analysis methods are required.

The EPSRC funded research programme, 4CU aims to enhance the fundamental understanding of CO₂ and its role in co-electrolysis by developing a suite of in-situ investigative methods for high temperature SOC operation.  Using Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) we can monitor both adsorbed and gas phase species in-situ.  Variation of potential and temperature conditions allow for visualization of surface mechanisms associated with single atmosphere fuel cell operation.  This, along with dual atmosphere measurements, will be discussed.  This work illustrates the applicability of the new technique for SOCs operated in a range of atmospheres using Au, Pt and Ag electrodes.  The comparison of potential dependent DRIFTS combined with electrochemical measurements provides an important insight into the roles of oxygen ion and proton transport within the systems studied.