SnO x surface modified Sr 2 Fe 1.5 Mo 0.5 O 6-δ cathode with enhanced electrocatalytic activities for direct CO 2 electrolysis in solid oxide electrolysis cells

Surface modification and/or reconstruction for perovskite oxides cathode is an efficient strategy to accelerate sluggish kinetics of CO reduction reaction (CO2RR) in solid oxide electrolysis cells (SOECs). Herein, active SnO nanoparticles with average size of ∼10 nm are loaded on the surface of Sr Fe Mo O (SFM) cathode via a facile wet infiltration method. Benefiting from improved specific surface area, expended three phase boundaries, optimized CO adsorption/activation abilities, as well as additional oxygen vacancies, the as-prepared SOEC with the SFM@SnO cathode delivers an enhanced current density of 0.691 A cm under an applied voltage of 1.5 V at 850 °C for the CO electrolysis, and successfully operates 100 h without any attenuation under 1.2 V at 800 °C. This work offers new insights into tailoring perovskite oxide cathode for the CO electrolysis in SOEC via a surface post-treatment strategy.