Designing highly active electrode by infiltration technique for co-electrolysis of CO₂ and H₂O

The efficient utilization of CO₂ emissions for energy storage and chemical synthesis is critical to achieving sustainable development. This study focuses on enhancing the performance of solid oxide electrolysis cells (SOECs) for intermediate-temperature co-electrolysis of CO₂ and H₂O to produce syngas. A novel infiltration technique was employed to introduce nanoscale binary-oxide catalysts, including lanthanide, transition, and alkaline earth metal oxides, into selected scaffold electrodes. Among these catalysts, cerium oxide (CeO₂) exhibited significant improvements in electrolysis current density and electrocatalytic activity when paring with the potential La(Sr)Fe(Mn)O₃ (LSFM) perovskite electrode material. Notably, due to the infiltration of CeO₂, a marked enhancement in electrolysis current density (> 60 %) can be achieved with exceptional Faradaic efficiency, in comparison to the non-infiltrated cell. The observed performance enhancement can be attributed to reduced internal resistances, improved microstructural connectivity, and increased active surface area. However, controlling the syngas product remains a challenge, with a bias toward H₂ production in all tested cells, primarily due to the strong influence of the water-gas shift reaction. Despite this limitation, the findings underscore the significant potential of Ce-oxide infiltrants as highly active catalysts for advancing CO₂/H₂O co-electrolysis applications.