Abstract
Solid oxide electrolysis cells provide a practical solution for the direct conversion of CO(2) to other chemicals (i.e. CO), however, an in-depth mechanistic understanding of the dynamic reconstruction of active sites for perovskite cathodes during CO(2) electrolysis remains a great challenge. Herein, we identify that iridium-doped Sr(2)Fe(1.45)Ir(0.05)Mo(0.5)O(6-δ) (SFIrM) perovskite displays a dynamic electrochemical reconstruction feature during CO(2) electrolysis with abundant exsolution of highly dispersed IrFe alloy nanoparticles on the SFIrM surface. The in situ reconstructed IrFe@SFIrM interfaces deliver a current density of 1.46 A cm(-2) while maintaining over 99% CO Faradaic efficiency, representing a 25.8% improvement compared with the Sr(2)Fe(1.5)Mo(0.5)O(6-δ) counterpart. In situ electrochemical spectroscopy measurements and density functional theory calculations suggest that the improved CO(2) electrolysis activity originates from the facilitated formation of carbonate intermediates at the IrFe@SFIrM interfaces. Our work may open the possibility of using an in situ electrochemical poling method for CO(2) electrolysis in practice.