TY - JOUR
T1 - Double perovskite cathodes for proton-conducting ceramic fuel cells
T2 - are they triple mixed ionic electronic conductors?
AU - Téllez Lozano, Helena
AU - Druce, John
AU - Cooper, Samuel J.
AU - Kilner, John A.
N1 - Funding Information:
This work was supported by World Premier Research Centre of the Ministry of Education, Culture, Sports, Science and Technology (MEXT).
Funding Information:
The authors acknowledge financial support from the International Institute for Carbon Neutral Energy Research (wpi-I2CNER), funded by the World Premier Research Centre of the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of the Japanese Government.
Publisher Copyright:
© 2017 The Author(s). Published by National Institute for Materials Science in partnership with Taylor & Francis.
PY - 2017/12/31
Y1 - 2017/12/31
N2 - 18O and 2H diffusion has been investigated at a temperature of 300 °C in the double perovskite material PrBaCo2O5+δ (PBCO) in flowing air containing 200 mbar of 2H2 16O. Secondary ion mass spectrometry (SIMS) depth profiling of exchanged ceramics has shown PBCO still retains significant oxygen diffusivity (~1.3 × 10−11 cm2s−1) at this temperature and that the presence of water (2H2 16O), gives rise to an enhancement of the surface exchange rate over that in pure oxygen by a factor of ~3. The 2H distribution, as inferred from the 2H2 16O− SIMS signal, shows an apparent depth profile which could be interpreted as 2H diffusion. However, examination of the 3-D distribution of the signal shows it to be nonhomogeneous and probably related to the presence of hydrated layers in the interior walls of pores and is not due to proton diffusion. This suggests that PBCO acts mainly as an oxygen ion mixed conductor when used in PCFC devices, although the presence of a small amount of protonic conductivity cannot be discounted in these materials.
AB - 18O and 2H diffusion has been investigated at a temperature of 300 °C in the double perovskite material PrBaCo2O5+δ (PBCO) in flowing air containing 200 mbar of 2H2 16O. Secondary ion mass spectrometry (SIMS) depth profiling of exchanged ceramics has shown PBCO still retains significant oxygen diffusivity (~1.3 × 10−11 cm2s−1) at this temperature and that the presence of water (2H2 16O), gives rise to an enhancement of the surface exchange rate over that in pure oxygen by a factor of ~3. The 2H distribution, as inferred from the 2H2 16O− SIMS signal, shows an apparent depth profile which could be interpreted as 2H diffusion. However, examination of the 3-D distribution of the signal shows it to be nonhomogeneous and probably related to the presence of hydrated layers in the interior walls of pores and is not due to proton diffusion. This suggests that PBCO acts mainly as an oxygen ion mixed conductor when used in PCFC devices, although the presence of a small amount of protonic conductivity cannot be discounted in these materials.
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U2 - 10.1080/14686996.2017.1402661
DO - 10.1080/14686996.2017.1402661
M3 - Article
AN - SCOPUS:85038375899
SN - 1468-6996
VL - 18
SP - 977
EP - 986
JO - Science and Technology of Advanced Materials
JF - Science and Technology of Advanced Materials
IS - 1
ER -