Enhancing Electrochemical CO2 Reduction of La(Sr)Fe(Mn)O3 with Metal (Ru, Ni, Co, and Fe) Catalytic Additives for High-Temperature CO2 Electrolysis Cells

Abstract

Solid oxide electrolysis cells (SOEC) have tremendous potential as highly efficient devices for high-temperature CO2 electrolysis. Commonly used Ni-based fuel electrodes experience inherent redox instabilities under direct CO/CO2 conditions. Therefore, the robust perovskite oxide La(Sr)Fe(Mn)O3 (LSFM) has been suggested as an alternative owing to its excellent coking resistance. However, LSFM electrodes are limited by their poor catalytic activity in CO2 reduction. To alleviate this problem, various metal additives have been added as catalysts to decrease the surface reaction barrier, which accelerates the chemical adsorption of CO2. In this study, the various metal catalysts (Ru, Co, Fe, and Ni) are deposited on the surface of LSFM electrode using the infiltration method. The distribution of the relaxation time (DRT) is investigated to confirm the catalytic activity for CO2 electrolysis. Consequently, when applied Fe catalyst in LSFM electrode, an electrolysis performance of 2.2 A cm-2 at 1.5 V in CO2 electrolysis was obtained at 1123 K.