| Abstrakt: |
Because of high oxygen semi-permeation and very good chemical stability, La0.8Sr0.2Fe0.7Ga0.3O3[?]d perovskite is one of the most promising materials as a catalytic membrane reactor for hydrogen production. In this paper, oxygen semi-permeation of La0.8Sr0.2Fe0.7Ga0.3O3[?]d membranes with different architectures is studied over a large range of temperatures in order to identify the rate determining step of the oxygen flux through the membrane. We show that the oxygen flux through the membrane is governed by the surface exchanges on the membrane reducing face. Besides, these results are confirmed by potentiometric measurements of oxygen activity on both membrane faces under oxygen partial pressure gradient. Finally, new architectures with La0.8Sr0.2Fe0.7Ni0.3O3[?]d porous catalytic layer on membrane reducing surface are tested to improve the performances of oxygen semi-permeation. |
