Tungstates (Ln(6)WO(12)) are considered as one of the most promising candidates for hydrogen separation membrane materials. Among varies Ln(6)WO(12) 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- (delta) (NWM) hollow fiber membranes have been studied systematically in this work. A high hydrogen permeation flux of 1.29 mL/min.min(2) was obtained at 975 C-omicron 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. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.