(Invited) High Temperature CO2 Electrolysis on La(Sr)Fe(Mn)O3 Oxide Cathode by Using LaGaO3 Based Electrolyte

Abstract

Electrochemical conversion of carbon dioxide to carbon monoxide (CO2→CO) is a potential useful step in the desirable transformation of the greenhouse gas to fuels or useful chemicals. In this study, the electrochemical conversion of CO2 to CO on oxide cathode was studied in a solid oxide electrolysis cell (SOEC) by using a LaGaO3-based electrolyte (La0.9Sr0.1Ga0.8Mg0.2O3, LSGM) at elevated temperature (i.e. 973 - 1173 K), which is a good candidate as electrolyte for electrolysis cell because of the high oxide ion conductivity at intermediate temperatures. It was found that a LaFeO3-δ–based perovskite material as cathode (La0.6Sr0.4Fe0.8Mn0.2O3-δ, LSFM6482) shows much higher activity for CO2 electrolysis among the examined oxide and a current density of CO2 electrolysis is achieved with a value of 0.52 A/cm2 at 1.6 V and 1173 K. Doping Sr and Mn to LaFeO3 is highly effective for increasing the cathode activity for CO2 electrolysis under the feed gas condition, which is consisted of 50%CO2, 1%CO, and 49%Ar. Porous structure with fine particle (0.5 μm) and main phase stability of LSFM6482 cathode can be sustained under CO2 electrolysis condition.