Testing the Chemical/Structural Stability of Proton Conducting Perovskite Ceramic Membranes by in Situ/ex Situ Autoclave Raman Microscopy

Membranes

Aneta Slodczyk²  Oumaya Zaafrani²  Matthew D. Sharp¹  John A. Kilner¹  Bogdan Dabrowski⁴  Olivier Lacroix³ 

[1] Department of Materials, Imperial College London, London SW7 2AZ, UK; E-Mails:;Laboratory of Dynamics, Interactions and Reactivity (LADIR), UMR7075 CNRS, Université Pierre et Marie Curie, 4 Pl. Jussieu, Paris 75005, France; E-Mails:;AREVA NP, Université Montpellier 2, Montpellier 34095, France; E-Mail:;Department of Physics, Northern Illinois University, DeKalb, IL 60115, USA; E-Mail:

关键词: perovskite;    proton conductor;    ceramic;    autoclave;    TGA;    IR;    Raman;    in situ;   

DOI  :  10.3390/membranes3040311

来源: mdpi

【 摘 要 】

Ceramics, which exhibit high proton conductivity at moderate temperatures, are studied as electrolyte membranes or electrode components of fuel cells, electrolysers or CO₂ converters. In severe operating conditions (high gas pressure/high temperature), the chemical activity towards potentially reactive atmospheres (water, CO₂, etc.) is enhanced. This can lead to mechanical, chemical, and structural instability of the membranes and premature efficiency loss. Since the lifetime duration of a device determines its economical interest, stability/aging tests are essential. Consequently, we have developed autoclaves equipped with a sapphire window, allowing in situ Raman study in the 25–620 °C temperature region under 1–50 bar of water vapor/gas pressure, both with and without the application of an electric field. Taking examples of four widely investigated perovskites (BaZr_0.9Yb_0.1O_3−δ, SrZr_0.9Yb_0.1O_3−δ, BaZr_0.25In_0.75O_3−δ, BaCe_0.5Zr_0.3Y_0.16Zn_0.04O_3−δ), we demonstrate the high potential of our unique set-up to discriminate between good/stable and instable electrolytes as well as the ability to detect and monitor in situ: (i) the sample surface reaction with surrounding atmospheres and the formation of crystalline or amorphous secondary phases (carbonates, hydroxides, hydrates, etc.); and (ii) the structural modifications as a function of operating conditions. The results of these studies allow us to compare quantitatively the chemical stability versus water (corrosion rate from ~150 µm/day to less than 0.25 µm/day under 200–500 °C/15–80 bar P_H2O) and to go further in comprehension of the aging mechanism of the membrane.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland.