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 La0.8Sr0.2Ga0.8Mn0.2O3 (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.