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

Abstract

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)5.5WO12-δ. The tungstates Ln6WO12 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)5.5WO12-δ were systematically analyzed, specifically, the influence of the H2 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 (2.5vol.% H2O), i.e., the highest hydrogen flux was 0.046mLmin−1cm−2 at 1000°C for membrane thickness of 0.9mm.