Development of mixed-conducting ceramic membranes for hydrogen separation.

摘要

SrCeO(sub 3)- and BaCeO(sub 3)-based proton conductors have been prepared and their transport properties have been investigated by impedance spectroscopy in conjunction with open circuit voltage and water vapor evolution measurements. BaCe(sub 0.8)Y(sub 0.2)O(sub 3-(delta)) exhibits the highest conductivity in a hydrogen-containing atmosphere; however, its electronic conductivity is not adequate for hydrogen separation in a nongalvanic mode. In an effort to enhance ambipolar conductivity and improve interfacial catalytic properties, BaCe(sub 0.8)Y(sub 0.2)O(sub 3-(delta)) cermets have been fabricated into membranes. The effects of ambipolar conductivity, membrane thickness, and interfacial resistance on permeation rates have been investigated. In particular, the significance of interfacial resistance is emphasized.