Enhancing CO₂ Catalytic Adsorption on an Fe Nanoparticle-Decorated LaSrFeO_4 + δ Cathode for CO₂ Electrolysis

The development of cathode materials with high catalytic activity and low cost is a challenge for CO₂ electrolysis based on solid oxide electrolysis cells. Herein, we report a low-cost and highly active metallic Fe nanoparticle-decorated Ruddlesden-Popper (La, Sr)FeO_4+δ cathode catalyst (Fe-RPLSF), which shows a high oxygen vacancy concentration and robust CO₂ reduction rate. At 850 °C, the current density of the electrolysis cell with the Fe-RPLSF cathode reaches -1920 mA cm^-2 at a voltage of 1.5 V, and the Faraday efficiency is as high as 100%. The polarization resistance at low frequency (0.1-10 Hz), which is the rate-limit step for CO₂ electrolysis, significantly decreases with the exsolved Fe nanoparticles because of improved CO₂ dissociative adsorption. Moreover, our electrolysis cell demonstrates acceptable short-term stability for direct CO₂ electrolysis.