In regards to co-electrolysis, mixed ionic electronic conductors (MIEC) have gained interest as alternatives to nickel-yttria stabilized zirconia (Ni-YSZ) because the active region is not limited to the triple phase boundary and they are more stable in reducing environments3. Gadolinia-doped ceria coupled with perovskite La1-xSrxCr1-yMnyO3-δ (GDC-LSCM) has been a particularly well studied MIEC3.
We are currently conducting NLEIS and EIS measurements of CO2 reduction, water reduction, and co-electrolysis reduction experiments on button cells composed of GDC and LSCM as the working electrode with electrolyte YSZ under various temperatures and gas compositions. Gas atmospheres surrounding the cells contain various mixtures of water, CO2, CO, H2, and carrier gas such as Ar or N2. Currently hypothesized mechanisms/models on H2O and CO2 reduction are considered and scrutinized against NLEIS data in order to further reveal the nature of water and CO2 reduction.
- Graves, C., Ebbesen, S. D., Mogensen, M., & Lackner, K. S. (2011). Sustainable hydrocarbon fuels by recycling CO2 and H2O with renewable or nuclear energy. Renewable and Sustainable Energy Reviews, 15(1), 1–23. https://doi.org/10.1016/j.rser.2010.07.014
- Graves, C., Chatzichristodoulou, C., & Mogensen, M. B. (2015). Kinetics of CO/CO2 and H2/H2O reactions at Ni-based and ceria-based solid-oxide-cell electrodes. Faraday Discussions, 182(0), 75–95. https://doi.org/10.1039/C5FD00048C
- Valdes-Espinosa, H., Stuve, E. M., & Adler, S. B. (2015). Modeling Water Reduction on 10 Mole% Gadolinia-Doped Ceria (GDC10) Porous Electrodes. ECS Transactions, 66(2), 229–251. https://doi.org/10.1149/06602.0229ecst