Dense ceramics with mixed protonic–electronic conductivity were of considerable interest for the separation and purification of hydrogen and as electrochemical reactors. In this work, the hydrogen permeability of a Sr0.97Ce0.9Yb0.1O3 − δ membrane with a porous Pt catalytic layer on the hydrogen feed-exposed side was studied over the temperature range 500–804C employing Ar as the permeate sweep gas. A SiO2–B2O3–BaO–MgO–ZnO-based glass-ceramic sealant was successfully employed to seal the membrane to the dual-chamber reactor. After 14 h of exposure to 10% H2:90% N2 at 804C, the H2 flux reached a maximum of 33nmol/cm2s, over an order of magnitude higher than that obtained on membranes of similar thickness without surface modification. The permeation rate then decreased slowly and moderately on annealing at 804C over a further 130h. Thereafter, the flux was both reproducible and stable on thermal cycling in the range 600–804C. The results indicated an important role of superficial activation processes in the flux rate and suggested that hydrogen fluxes could be further optimised in cerate-based perovskites.

Hydrogen-Permeation Characteristics of a SrCeO3-Based Ceramic Separation Membrane: Thermal, Ageing and Surface-Modification Effects. G.C.Mather, D.Poulidi, A.Thursfield, M.J.Pascual, J.R.Jurado, I.S.Metcalfe: Solid State Ionics, 2010, 181[3-4], 230-5