Fundamental modeling and experimental validation of hydrogen and oxygen transport through mixed ionic and electronic conducting membranes

Hydrogen transporting mixed ionic and electronic membranes offer tremendous opportunities for process intensification and energy savings in various applications such as reaction chemistries and heat/energy generation. Over the past several decades there has been significant advancement in the membrane materials science to produce improved molecular transport, but commercial adoption is still limited. To escalate implementation, a fundamental understanding of the solid state membrane transport and the water splitting phenomenon would bridge the gap for process conceptualization and design. This work presents a fundamental transport model, which quantifies the contribution of the water splitting phenomenon to the overall observed apparent flux of hydrogen and oxygen through ionic and electronic conducting membranes. The model predictions are rigorously validated against experimental data gathered in parallel. Membranes tested were based on the composition La0.87Sr0.13CrO3-δ-La5.4WO12-δ. These measurements include both apparent hydrogen/oxygen fluxes and the water splitting contributions over a range of operating conditions that included varying temperatures, hydrogen partial pressures, and hydration gradients across the membrane.