Electrochemical performance of La0.3Sr0.7Ti0.3Fe0.7O3-δ/CeO2 composite cathode for CO2 reduction in solid oxide electrolysis cells

Abstract

Solid Oxide Electrolysis Cells offer great promise for efficient recycle and cost-effective conversion of carbon dioxide. However, the conventional Ni/YSZ and some other fuel electrodes suffer some technological limitations such as the use of protecting gas CO/H2. Here we demonstrate the efficient electrochemical reduction of carbon dioxide without flowing any protecting gases based on the porous cathode with La0.3Sr0.7Ti0.3Fe0.7O3-δ(LSTF) nanostructured composite which is infiltrated into a scandia-stabilized zirconia scaffold together with ceria. The infiltrated porous electrode provides excellent performance for CO2 electrolysis. By I–V measurement and electrochemical impedance spectroscopic characterization, it shows that the current densities during electrolysis below a cell voltage of 2 V is between 1.20 and 4.44 A cm−2, increasing with temperature increase over the temperature range of 700–850 °C, and the cell with configuration of LSTF/CeO2|ScSZ|LSM/ScSZ possesses low electrode polarization resistances (Rp) within different voltage ranges, for example, Rp = 0.18 Ω cm2 at an applied voltage of 2.0 V, which is one order of magnitude lower than other reported electrode materials such as La0.2Sr0.8TiO3+δ. Moreover, a combination of short-term stability test for 48 h and cyclic stability test of LSTF/CeO2 are also estimated, and the results show that the nanostructured LSTF/CeO2 is highly effective for CO2 electrolysis.