Lanthanum chromate-based perovskite oxides have attracted great attention as the cathode materials in the high-temperature CO2 electrolysis because of its good redox stability. However, the unsatisfied electrochemical catalytic activity and insufficient adsorption of CO2 at operating temperature still hindered the further improvement of electrochemical performance and the Faraday efficiency of the electrolysis cell. In this work, the catalytic and redox active Ce was doped into A site of La0.7Sr0.3Cr0.5Fe0.5O3-δ (LSCrF) to promote the catalytic performance, and to introduce oxygen vacancies in the lattice in situ after reduction under the operational condition. The increased amount of oxygen vacancies not only facilitates the mobility of oxygen ions, but also provides favorable accommodation for chemical adsorption of CO2. The CO2 electrolysis tests demonstrated the superior electrochemical performances, higher Faraday efficiencies of the Ce-doped LSCrF cathode catalyst in comparison with that without Ce doping, indicating the perspective application of this functional material.
Keywords: carbon dioxide; catalysts; electrochemical reduction; perovskite oxide; solid oxide electrolysis cells.