Hydrogen production by high-temperature water splitting using mixed oxygen ion-electron conducting membranes.

Hydrogen production from water splitting at high temperatures has been studied with novel mixed oxygen ion-electron conducting cermet membranes. Hydrogen production rates were investigated as a function of temperature, water partial pressure, membrane thickness, and oxygen chemical potential gradient across the membranes. The hydrogen production rate increased with both increasing moisture concentration and oxygen chemical potential gradient across the membranes. A maximum hydrogen production rate of 4.4 cm{sup 3}/min-cm{sup 2} (STP) was obtained with a 0.10-mm-thick membrane at 900 C in a gas containing 50 vol.% water vapor in the sweep side. Hydrogen production rate also increased with decreasing membrane thickness, but surface kinetics play an important role as membrane thickness decreases.