Enhanced CO2 electrolysis with synergistic doping in perovskite cathode materials

Abstract

Traditional metal and cermet cathodes are easily oxidized when performing CO₂ electrolysis without flowing reducing gas, resulting in the degradation of the electrolysis performance. Ceramic cathodes would demonstrate durable performance but their catalytic activity is normally limited. Here we engineer the perovskite La_0.6Sr_0.4Co_1−xFe_xO_3−δ (LSC_1−xF_x, x = 0–1) with synergistic doping in the B site to tailor the catalytic activity. In this work, we synthesize perovskite materials LSC_1−xF_x and explore their electrochemical performance. The replacement of Co with Fe increases the concentration of low valence Fe ions linked to oxygen vacancies and improves the catalytic activity for CO₂ electrolysis. The LSC_0.2F_0.8 cathode has the highest electrochemical performance with a current density of 0.92 A cm⁻² and a CO production of 5.49 ml min⁻¹ cm⁻² at 1.6 V and 850 °C. We show the excellent chemical stability in CO₂ electrolysis through continuous operation for 100 h. This work provides a new idea for improving the catalytic activity and stability of perovskite cathode materials in solid oxide electrolysis cells.