Novel Composite Fuel Electrode for CO2/CO-RSOCs

Reversible solid oxide cell (RSOC) technology allows use of a single device to efficiently derive chemicals from power (power-to-fuel) and power from chemicals (fuel-to-power). Fuel flexibility is a key aspect, as developing SOCs able to operate on fuels other than hydrogen can ease their integration into existing infrastructure. In addition, H2O and/or CO2 reduction is favorable in SOECs as polarization losses are reduced at high temperature. Here, a composite fuel electrode, 60 wt.% La0.6Sr0.4Fe0.8Mn0.2O3-delta (LSFMn) and 40 wt.% (5 wt.% Ni)-containing Ce0.85Sm0.15O2-delta (Ni-SDC) was investigated in H-2-fueled, CO-fueled SOFCs and for CO2 reduction in SOEC mode. In reducing conditions, Fe exsolved from the LSFMn perovskite formed a Ni-Fe alloy with Ni present on SDC. The composite fuel electrode showed remarkable activity for CO2 reduction with a current density output of 1.40 A cm(-2) (1.5 V) at 850 degrees C. SOFC/SOEC cell reversibility was obtained in different CO2:CO mixtures. Electrochemical impedance spectroscopy analysis was used to better understand cell mechanisms in SOFC and SOEC mode.

Automated summary

RSOC technology allows efficient conversion of power to chemicals and vice versa, with fuel flexibility being a key aspect for integration into existing infrastructure. A composite fuel electrode showed remarkable activity for CO2 reduction, highlighting the potential for reversible solid oxide cells in different operating conditions.