Charge transfer in mixed proton, oxygen ion and electron solid oxide conductor

Analysis of the equivalent scheme of the mixed proton-oxygen ion-electron conductor (MPOEC) allowed to obtain relationships between parameters of the membrane (total conductivity and transfer numbers) and parameters of the charge and mass transfer through the membrane (partial ion and electron currents, the specific flux of hydrogen at the cathode membrane surface) under regime of electrochemical reforming. It was stated that presence of proton conductivity in addition to oxygen ion conductivity led to increase of total flux of produced hydrogen. However, under conditions typical for the electrochemical reforming of methane into hydrogen, the specific hydrogen flux is about four times lower in the case when the membrane has proton-electron conductivity than in the case when the membrane has oxygen ion-electron conductivity. Paper presented at the Patras Conference on Solid State Ionics — Transport Properties, Patras, Greece, Sept. 14 – 18, 2004.