Oxygen diffusion, surface exchange and oxygen semi-permeation performances of Ln2NiO4+δ membranes (Ln = La, Pr and Nd)

Pierre-Marie Geffroy (1) , Mickaël Reichmann (1) , Thierry Chartier (1) , Jean-Marc. Bassat (2) , Jean-Claude Grenier (2)

1 Axe 1 : procédés céramiques
2 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux

In order to clearly identify the rate determining step (rds) in oxygen semi-permeation of dense Ln2NiO4+δ membranes (with Ln = La, Pr and Nd), a specific setup has been designed, which allowed measuring the oxygen semi-permeation flux as well as the oxygen activity gradient at both membrane surfaces. From the results of the measurements, the coefficients of oxygen diffusion and surface exchange at both membrane surfaces have been determined. Their values have been compared with the values reported in the literature for similar membrane materials. The main conclusion is that the oxygen flux through these membranes is limited by the oxygen surface exchange at the oxygen-lean face, and not, as previously claimed, by oxygen volume diffusion.

Mots clés: Oxygen diffusion; Oxygen surface exchange; Oxygensemi-permeation; Lanthanum nickelate

Domaines: Matériaux

Pierre-Marie Geffroy, Mickaël Reichmann, Thierry Chartier, Jean-Marc. Bassat, Jean-Claude Grenier. Oxygen diffusion, surface exchange and oxygen semi-permeation performances of Ln2NiO4+δ membranes (Ln = La, Pr and Nd). Journal of Membrane Science, 2014, 451, pp.234-242. ⟨10.1016/j.memsci.2013.08.035⟩. ⟨hal-00907657⟩