Coupled Surface-Bulk Engineering of Ceria-Based Cathodes Enables High-Temperature CO<sub>2</sub> Electrolysis.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 42258453.
- Also identified by DOI 10.1021/acs.nanolett.6c02089.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
Solid oxide electrolysis cells (SOECs) enable efficient high-temperature electrochemical CO<sub>2</sub> conversion, yet cathode performance is limited by insufficient surface reactivity and bulk transport. Herein, we report a coupled engineering strategy to enhance surface reactivity and bulk transport of Ce-based cathodes via rational dual-metal (Co, Fe) incorporation. The resulting Co<sub>0.05</sub>Fe<sub>0.05</sub>-incorporated Gd-doped ceria (Co<sub>0.05</sub>Fe<sub>0.05</sub>-GDC) exhibits enriched surface Ce<sup>3+</sup>-oxygen vacancy (Ce<sub>surf.</sub><sup>3+</sup>-<i>V</i><sub>O</sub>) motifs and improved bulk transport. A single cell with the Co<sub>0.05</sub>Fe<sub>0.05</sub>-GDC cathode achieves a current density of 1.88 A cm<sup>-2</sup> (2.20 A cm<sup>-2</sup> with a thinner 250 μm electrolyte) at 800 °C under 1.6 V and demonstrates stable operation for 580 h. Mechanistic studies reveal that Fe promotes CO<sub>2</sub> adsorption, activation, and dissociation via enriched Ce<sub>surf.</sub><sup>3+</sup>-<i>V</i><sub>O</sub> motifs and active Fe sites, whereas Co lowers the oxygen migration barrier and narrows the bandgap, overcoming bulk transport limitations. This work provides a cost-effective design for high-performance ceria-based cathodes by coupling surface reactivity with bulk transport.