A symmetrical solid oxide electrolysis cell supported by nanostructured electrodes for highly efficient CO2 electrolysis

• Published in: Journal of power sources 2024-08, Vol.610, p.234742, Article 234742
• Main Authors: Wang, Mengmeng, Wang, Junru, Du, Jishi
• Format: Article
• Language: English
• Subjects: CO2 electrolysis; Coking-resistance; Infiltration; Symmetrical solid oxide electrolysis cells; Vertically-aligned pores
• ISSN: 0378-7753
• DOI: 10.1016/j.jpowsour.2024.234742

High-temperature carbon dioxide (CO2) electrolysis in solid oxide electrolysis cells (SOECs) is a promising strategy for the electrochemical conversion of CO2 into valuable chemical fuels powered by renewable energy. However, nowadays SOECs are still dominated by the state-of-the-art nickel-yttria stabilized zirconia (Ni-YSZ) cathode which suffers from oxidation at high CO2 concentration and coking at high carbon monoxide (CO) concentration. Herein, a novel symmetrical cell supported by La0.75Sr0.25Cr0.5Fe0.5O3-δ (LSCrF)-YSZ ceramic electrodes is developed for pure CO2 electrolysis. The electrode has a hierarchical pore structure modified with Gd0.2Ce0.8O1.9 (GDC) nano-catalysts on the inner surface of the scaffold. The cell delivers an ultra-high electrochemical performance for pure CO2 electrolysis, e.g., the current density is 1.44 A cm−2 at 1.5 V and 800 °C. The distribution of relaxation time (DRT) analysis reveals that the vertically-aligned pores facilitate the infiltration of GDC nano-catalysts and the fast gas transport, while the skin layer adjacent to the electrolyte modified with highly continuous GDC nano-catalysts provides abundant active sites. Particularly, the cell also demonstrates excellent electrolysis performance in CO2-lean atmosphere and impressive durability in CO-rich atmosphere. This work presents a highly promising unique architecture of SOECs for CO2 electrolysis. A novel symmetrical solid oxide electrolysis cell supported by La0.75Sr0.25Cr0.5Fe0.5O3-δ (LSCrF)-YSZ ceramic electrodes is developed. The electrode has a hierarchical pore structure modified with Gd0.2Ce0.8O1.9 (GDC) nano-catalysts on the inner surface of the scaffold, which has high electrolysis performance for pure CO2 by virtue of the absence of concentration polarization and the reduced activation polarization of the electrode. The cell also shows high coking-resistance under high CO atmosphere. [Display omitted] •A novel symmetrical cell supported by LSCrF-YSZ ceramic electrodes is developed.•The electrode has a hierarchical pore structure modified with GDC nano-catalysts.•Unique pores facilitate the infiltration and the fast gas transport.•The cell shows superior electrolysis performance for pure CO2.•The cell demonstrates high coking-resistance under high CO atmosphere.