Building efficient and durable 3D nanotubes electrode for solid oxide electrolytic cells

Solid oxide electrolytic cells (SOEC) have great potential in CO2 conversion and energy storage. However, commercial application of SOEC is still challenging due to the sluggish rate of CO2 electrochemical reduction caused by the arduous activation and limited CO(2 )adsorption on cathode surface. In this study, synergetic regulation strategy on intrinsic catalysis activity and surface amelioration is proposed to improve the CO2 adsorption capacity and increase the adsorption sites. This strategy is demonstrated in a Cu-doped three-dimensional (3D) porous Sr2Fe1.3Cu0.2Mo0.5O6-delta (SECuM) nanotube cathode. The results indicate that SFCuM nanotube shows more oxygen vacancies and excellent oxygen ion conduction. At the same time, the nanostructure provides a larger three-phase reaction interface and more reaction sites for CO2 reduction reaction (CO2RR). Benefiting from these merits, the maximum electrolytic current density of the designed SFCuM electrode can be improved to 1.68 A cm(-2) at 750 degrees C and the related polarization resistance can be lowered to 0.59 Omega cm(2). In addition, the porous SFCuM nanotube electrode also showed good stability at a constant electrolytic voltage of 1.5 V, with no performance decay during continuous 200-h operation. Such a synergetic regulation strategy may provide some new insight on catalyst design and modification for high-activity CO2RR electrode.