Hydrogen permeation through thin supported SrCe0.7Zr0.2Eu0.1O3−δ membranes; dependence of flux on defect equilibria and operating conditions

Hydrogen permeation through SrCe0.7Zr0.2Eu0.1O3−δ membranes was investigated as a function of temperature, feed H2O partial pressure, feed H2 partial pressure and flow rate. Hydrogen permeation flux was proportional to the transmembrane H2 partial pressure gradient with a 1/4 dependence. A maximum H2 permeation flux of 0.23 and 0.21 cm3/cm2 min was obtained at 900 °C for 100% H2 and 97 vol% H2/3 vol% H2O conditions, respectively. The activation energy decreased with increasing H2 partial pressure and/or decreasing steam partial pressure. Permeation flux through the SrCe0.7Zr0.2Eu0.1O3−δ membrane was stable under wet H2, water gas shift reaction and steam reforming of methane conditions.

► H2/O2/H2O equilibria effect on H2 permeation of proton–electron conducting membranes.
► Flux limited by electron conductivity, which decreases with increasing O2 partial pressure.
► Excellent agreement is obtained between permeation and ambipolar conductivity.
► Membrane is stable under water gas shift and steam reforming conditions.