High Temperature Electrolysis Using a Pilot-Scale Cathode-Supported Tubular Solid Oxide Fuel Cell

A Siemens cathode-supported solid oxide fuel cell was explored in this study to operate as an electrolysis cell to produce H-2 from steam. An in-situ oxygen sensor was implemented in the cell assembly to determine the oxide-to-fuel ratio in the effluent, from which the rate of H-2 production and steam utilization were calculated. No H-2 was added into the initial steam. The results showed that the rate of H-2 production linearly increased with the applied current and the steam can be split into H-2 at high utilization. After hundreds of hours' operation, no degradation was observed. However, it was found that the presence of mixed ionic-electronic conduction in the electrolyte/interconnection layers could lead to a lower rate of H-2 production and reduced conversion efficiency.