Download or read book Development of Mixed-conducting Oxides for Gas Separation written by and published by . This book was released on 1997 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mixed-conducting oxides have been used in many applications, including fuel cells, gas separation membranes, sensors, and electrocatalysis. The authors are developing a mixed-conducting, dense ceramic membrane for selectively transporting oxygen and hydrogen. Ceramic membranes made of Sr-Fe-Co oxide, which has high combined electronic and oxygen ionic conductions, can be used to selectively transport oxygen during the partial oxidation of methane to synthesis gas (syngas, CO + H2). The authors have measured the steady-state oxygen permeability of SrFeCo{sub 0.5}O(subscript x) as a function of oxygen-partial-pressure gradient and temperature. At 900°C, oxygen permeability was (almost equal to)2.5 scc·cm−2·min−1 for a 2.9-mm-thick membrane and this value increases as membrane thickness decreases. The authors have fabricated tubular SrFeCo{sub 0.5}O(subscript x) membranes and operated them at 900°C for>1000 h during conversion of methane into syngas. The hydrogen ion (proton) transport properties of yttria-doped BaCeO3 were investigated by impedance spectroscopy and open-cell voltage measurements. High proton conductivity and a high protonic transference number make yttria-doped BaCeO3 a potential membrane for hydrogen separation.