Highly efficient, coke-free electrolysis of dry CO2 in solid oxide electrolysis cells

• DOI: 10.1016/j.cej.2024.148532
• Publication Date: 2024-01-04T00:49:30Z
• Authors: Haewon Seo; Seungsoo Jang; Wooseok Lee; Kyung Taek Bae; Kang Taek Lee; Jongsup Hong; Kyung Joong Yoon
• Keywords: Overpotential; Partial pressure; Carbon fibers; High Temperature Electrolysis

Dry CO2 electrolysis in solid oxide cells (SOECs), a highly efficient, versatile method for converting into value-added products, is critically limited by carbon deposition on Ni-based fuel electrodes. We achieved coke-free using SOECs elaborately controlling the local gas environments. Multilayered electrode microstructures were systematically engineered to facilitate mass transport and maintain CO partial pressure below threshold formation. A fuel-electrode-supported cell with an improved microstructure operated stably 500 h without coking at 0.50 cm−2 700 °C, whereas conventional ones failed immediately. Multiphysics modeling coupled three-dimensional quantitative microstructural analysis confirmed our successfully mitigated deposition. Furthermore, enhanced substantially lowered overpotential increased production rate > 50 %. These results highlight feasibility of dry commercially viable materials properties.