Hydrogen permeation through thin supported SrZr0.2Ce0.8−xEuxO3−δ membranes

SrZr0.2Ce0.8−xEuxO3−δ (x = 0.1 and 0.15) membranes were investigated for their hydrogen permeation properties as a function of membrane thickness, from 17 to 50 μm. Membrane permeation flux was proportional to image matching Norby and Larringʹs model when protons and electrons are the dominating defects. The observed inverse linear dependence of flux with membrane thickness indicates bulk diffusion is the rate-limiting factor for hydrogen permeation. After correcting for water formation, higher Eu doping in the membrane was confirmed to result in greater hydrogen flux, consistent with our previous conductivity studies. A H2 flux of 0.35 cc/min cm2 was achieved for 17 μm thickness SrZr0.2Ce0.7Eu0.1O3−δ membrane at 900 °C and 100% H2 in the feed gas. However, taking observed water vapor formation into consideration, a maximum H2 flux of 0.50 cc/min cm2 was achieved under the same conditions.