Study of hydrogen permeation in (La5/6Nd1/6)5.5WO12-δ membranes

This work presents the preparation and characterization of the hydrogen permeation of a mixed protonic-electronic conducting membrane based on the doped system La6WO12, in this instance, (La5/6Nd1/6)(5.5)WO12-delta. The tungstates Ln(6)WO(12) present sufficient protonic and electronic mixed conductivity and stability in moist CO2 environments and are potential candidates for the separation of hydrogen at high temperatures. Hydrogen separation properties of (La5/6Nd1/6)(5.5)WO12-delta were systematically analyzed, specifically, the influence of the H-2 concentration in feed stream, humidification degree and operating temperature on the hydrogen separation were studied. The best permeation results were achieved when both membrane sides were humidified (2.5 vol.% H2O), i.e., the highest hydrogen flux was 0.046 mL min(-1) cm(-2) at 1000 degrees C for membrane thickness of 0.9 mm. (C) 2011 Elsevier B.V. All rights reserved.