The potential to convert CO2 into synthetic fuel forms a major pathway for global CO2 utilization and could address the issues of depleting fossil fuel reserves and global warming, however, the reaction mechanisms occurring during cell operation for a co-electrolysis system are currently not well understood. This information is necessary to improve performance by engineering materials and operating conditions which are ideal for high gas conversion rates and long term cell performance. Previous studies have suggested that carbonate species may be an important intermediate to CO2 reduction during electrolysis and shows dependencies with temperature and applied potential.[1] This study investigates the electrochemical impedance of electrolysis cells to determine potential rate limiting mechanisms occurring during cell operation. Results correlating cell performance to surface species detected in-situ using Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) obtained under varying fuel and temperature conditions will be discussed.
[1] D.J. Cumming, C. Tumilson, R. Taylor, S. Chansai, A.V. Call, J. Jacquemin, C. Hardacre, R.H. Elder,
Faraday Discuss., 2015, 182, 97-111