CO2-tolerant U-shaped hollow fiber membranes for hydrogen separation

•U-shaped NWM hollow fiber membrane has been prepared and used for H2 separation.•A H2 permeation flux of 1.29 mL/min·min2 can be obtained at 975 °C.•NWM hollow fiber membrane shows good CO2 stability.

Tungstates (Ln6WO12) are considered as one of the most promising candidates for hydrogen separation membrane materials. Among varies Ln6WO12 materials, the molybdenum doped neodymium tungsten oxides have attracted increasing attention due to their sufficient mixed proton-electron conductivity and high tolerance towards acid gases, such as CO2 and H2S. The hydrogen permeation properties of the U-shaped Nd5.5W0.5Mo0.5O11.25-δ (NWM) hollow fiber membranes have been studied systematically in this work. A high hydrogen permeation flux of 1.29 mL/min·min2 was obtained at 975 °C using 80% H2-20% He as feed gas and humidified Ar as sweep gas. Furthermore, the U-shaped NWM hollow fiber membrane present a hydrogen permeation flux with only a slight decrease during 80 h's operation feeding with the CO2-containing gas.