A CO 2 ‐stable hollow‐fiber membrane with high hydrogen permeation flux

A Mo‐substituted lanthanum tungstate mixed proton‐electron conductor, La 5.5 W 0.6 Mo 0.4 O 11.25−δ (LWM04), was synthesized using solid state reactions. Dense U‐shaped LWM04 hollow‐fiber membranes were successfully prepared using wet‐spinning phase‐inversion and sintering. The stability of LWM04 in a CO 2 ‐containing atmosphere and the permeation of hydrogen through the LWM04 hollow‐fiber membrane were investigated in detail. A high hydrogen permeation flux of 1.36 mL/min cm 2 was obtained for the U‐shaped LWM04 hollow‐fiber membranes at 975°C when a mixture of 80% H 2 −20% He was used as the feed gas and the sweep side was humidified. Moreover, the hydrogen permeation flux did not significantly decrease over 70 h of operation when fed with a mixture containing 25% CO 2 , 50% H 2 , and 25% He, indicating that the LWM04 hollow‐fiber membrane has good stability under a CO 2 ‐containing atmosphere. © 2015 American Institute of Chemical Engineers AIChE J , 61: 1997–2007, 2015