Development of a Tubular Solid Oxide Cell for Co-Electrolysis of H2O and CO2 for Syngas Production

A tubular Ni-8YSZ/SSZ/GDC/SSC (Strontium-doped Samarium Cobaltite) cell was prepared for high temperature co-electrolysis of H₂O and CO₂. This cell enhanced a current density at750ºC and 1.28 V by two-fold compared to a previous type of our cell. Measurements of voltage-current density (V-J) curves revealed that 0.55 A/cm² was attained at 750ºC and a thermoneutral voltage (1.33 V). The V-J curves were not influenced by change of H₂/C (= 2-4) and flow-rate ratio (= 1-4) of positive electrode to negative one. In addition, V-J curve measurement at constant 80% utilization of H₂O and CO₂ clarified that the cell was stable at the high utilization and 0.41 A/cm² was achieved at the thermoneutral voltage.