Comprehensive understanding of alkaline-earth elements effects on electrocatalytic activity and stability of LaFe0.8Ni0.2O3 electrode for high-temperature CO2 electrolysis

Symmetrical solid oxide electrolysis cell (SSOEC) is a promising energy conversion device for CO2 electroreduction due to their high efficiency, low cost and good stability. However, electrode materials with lower catalytic activity limit their development. In this work, optimization of LaFe0.8Ni0.2O3 (LFN) electrode using various A-site doping strategies was explored in SSOEC applications. The effect of the A-site doping elements Ca, Sr, Ba on the structure and physic-chemical property of LFN was assessed. The electrochemical performance including half-cell performance and CO2 electrolysis performance has been investigated. The results demonstrated that Ca doped LFN (LCFN) exhibits the best electrolysis performance and superior operation stability. The polarization resistance and the current density of the LCFN single cell at 2.0 V is 0.113 Ω cm2 and 0.876 A cm−2 at 800°C, respectively. Compared with Sr and Ba, Ca doped LFN exhibits appropriate conductivity, suitable oxygen vacancy concentration and high activation performance for O2 and CO2.Therefore, La0.6Ca0.4Fe0.8Ni0.2O3 is a promising material for SSOEC electrode.