Abstract
Dense ceramics with mixed protonic-electronic conductivity are 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 (SCYb) membrane with a porous Pt catalytic layer on the hydrogen feed-exposed side has been studied over the temperature range 500-804 °C 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 804 °C, the H2 flux reached a maximum of 33 nmol cm- 2 s- 1, 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 804 °C over a further 130 h. Thereafter, the flux was both reproducible and stable on thermal cycling in the range 600-804 °C. The results indicate an important role of superficial activation processes in the flux rate and suggest that hydrogen fluxes can be further optimised in cerate-based perovskites.
Original language | English |
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Pages (from-to) | 230-235 |
Number of pages | 6 |
Journal | Solid State Ionics |
Volume | 181 |
Issue number | 3-4 |
DOIs | |
Publication status | Published - 24 Feb 2010 |
Keywords
- Glass-ceramic seal
- Hydrogen permeation
- Hydrogen-separation membrane
- Perovskite
- Protonic-electronic conduction
- SrCeO
- Thermal history
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics
- Chemistry(all)