Efficient CO2 electroreduction on a solid oxide electrolysis cell with La0.6Sr0.4Co0.2Fe0.8O3−δ-Gd0.2Ce0.8O2-δ infiltrated electrode

Abstract

Solid oxide electrolysis cells are promising electrochemical devices for converting CO2 to useful products with high efficiency and simultaneously storing renewable energy. We here report a cell infiltrated with La0.6Sr0.4Co0.2Fe0.8O3−δ-Gd0.2Ce0.8O2-δ composite on yttria-stabilized zirconia scaffold as cathode and anode for CO2 electroreduction. The cell delivers a current density of −1.01 A cm−2 at 1.4 V and 800 °C, along with an CO production rate of 6.95 mL min−1 cm−2 and a Faraday efficiency of 98.8%. CO2 electroreduction on La0.6Sr0.4Co0.2Fe0.8O3−δ-Gd0.2Ce0.8O2-δ cathode passes through two charge transfer reactions, in which the second charge transfer reaction from the carbonate intermediate reduction to CO is the key rate-dtermining step. The cell also exhibits little performance degradation during a 220 h run under a current density of −0.20 A cm−2 at 800 °C.