Enhancing CO2 electrolysis performance with various metal additives (Co, Fe, Ni, and Ru) – decorating the La(Sr)Fe(Mn)O3 cathode in solid oxide electrolysis cells

Abstract

Perovskite oxide shows great promise as an alternative fuel electrode material in solid oxide electrolysis cells (SOEC) for the specific CO₂ electrochemical reduction, because of its excellent coking resistance. However, use of perovskite oxide is limited by its poor catalytic activity in CO₂ reduction. In this study, we investigated the use of various metal additives (Co, Fe, Ni, and Ru) on a La(Sr)Fe(Mn)O₃ (LSFM) fuel electrode for CO₂ reduction in a commercial infiltration process. Based on the electrochemical impedance spectroscopy (EIS) results, we determined the catalytic activity and reaction kinetics of CO₂ reduction for metal catalysts. In addition, the distribution of relaxation times analysis was conducted to investigate the adsorption and dissociation processes of CO₂ molecules for each catalyst. Consequently, when the Fe catalyst was applied in a LSFM fuel electrode for La_0.8Sr_0.2Ga_0.8Mn_0.2O₃ (LSGM) electrolyte-supported cells, an electrolysis performance of 2.201 A cm⁻² at 1.5 V in CO₂ electrolysis was obtained at 1123 K.