Structure and Dynamics Investigations of Sr/Ca-Doped LaPO₄ Proton Conductors

Journal Article · 15 May 2017 · Journal of Physical Chemistry. C

DOI: https://doi.org/10.1021/acs.jpcc.7b02254 · OSTI ID:1376312

al-Wahish, Amal  ^[1]; al-Binni, U. ^[2]; Tetard, L. ^[3]; Bridges, Craig A. ^[4]; Kharel, Krishna ^[5]; Günaydın-Şen, Özge ^[5]; Huq, A. ^[6]; Musfeldt, J. L.  ^[7]; Paranthaman, M. P.  ^[4]; Mandrus, D. ^[8]

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1. Univ. of Missouri, Columbia, MO (United States). Research Reactor
2. Univ. of Washington, Seattle, WA (United States). Dept. of Physics and Astronomy
3. Univ. of Central Florida, Orlando, FL (United States). NanoScience Technology Center
4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical Sciences Division
5. Lamar Univ., Beaumont, TX (United States). Dept. of Chemistry and Biochemistry
6. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical and Engineering Materials Division
7. Univ. of Tennessee, Knoxville, TN (United States). Dept. of Chemistry; Univ. of Tennessee, Knoxville, TN (United States). Dept. of Physics and Astronomy
8. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science & Technology Division; Univ. of Tennessee, Knoxville, TN (United States). Dept. of Physics and Astronomy; Univ. of Tennessee, Knoxville, TN (United States). Dept. of Materials Science and Engineering

Proton conductors loom out of the pool of candidate materials with great potential to boost hydrogen alternatives to fossil-based resources for energy. Acceptor doped lanthanum orthophosphates are considered for solid oxide fuel cells (SOFCs) for their potential stability and conductivity at high temperature. By exploring the crystal and defect structure of x% Sr/Ca-doped LaPO₄ with different nominal Sr/Ca concentrations (x = 0 – 10) with Neutron powder diffraction (NPD) and X-ray powder diffraction (XRD), we confirm that Sr/Ca-doped LaPO₄ can exist as self-supported structures at high temperatures during solid oxide fuel cell operation. Thermal stability, surface topography, size distribution are also studied to better understand the proton conductivity for dry and wet compounds obtained at sintering temperatures ranging from 1200 to 1400 °C using a combination of scanning electron microscopy (SEM), Atomic Force Microscopy (AFM), Fourier transform infrared spectroscopy (FTIR) and electrochemical impedance spectroscopy (EIS). In conclusion, the results suggest that Sr doped samples exhibit the highest proton conductivity of our samples and illustrate the impact of material design and versatile characterization schemes on the development of proton conductors with superior functionality.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
• Grant/Contract Number: AC05-00OR22725; FG02-01ER45885
• OSTI ID: 1376312
• Journal Information: Journal of Physical Chemistry. C, Journal Name: Journal of Physical Chemistry. C Journal Issue: 22 Vol. 121; ISSN 1932-7447
• Publisher: American Chemical SocietyCopyright Statement
• Country of Publication: United States
• Language: English

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