Novel quasi-symmetrical solid oxide electrolysis cells with in-situ exsolved cathode for CO2 electrolysis

Symmetrical solid oxide electrolysis cells have attracted increasingly attention because of their structural advantages as well as low cost. Herein, we demonstrate a novel quasi-symmetrical solid oxide electrolysis cell with reduced La0.6Sr0.4Fe0.8Ni0.2O3-delta as cathode and La0.6Sr0.4Fe0.8Ni0.2O3-delta as anode for pure CO2 electrolysis. After reduction, alloy nanoparticles are in-situ exsolved and oxygen vacancies are formed in La0.6Sr0.4Fe0.8Ni0.2O3-delta lattices. The cell with reduced La0.6Sr0.4Fe0.8Ni0.2O3-delta cathode shows current density of 1.42 A/cm(2) at 2.0 V under 850 degrees C for CO2 electrolysis, with lower polarization resistance (0.06 Omega.cm(2)), higher Faraday efficiency (98%) and better long-term stability compared to the cell with La0.6Sr0.4Fe0.8Ni0.2O3-delta cathode at 850 degrees C. The enhancement mechanism can be ascribed to the synergistic effect of the in-situ exsolved Ni-Fe nanoparticles and oxygen vacancies. The results illustrate that the quasi-symmetrical solid oxide electrolysis cells with reduced La0.6Sr0.4Fe0.8Ni0.2O3-delta cathode demonstrate promising application for CO2 electrolysis.