ic8b03593_si_001.pdf (329.75 kB)
Ba2ScHO3: H– Conductive Layered Oxyhydride with H– Site Selectivity
journal contribution
posted on 2019-02-19, 22:13 authored by Fumitaka Takeiri, Akihiro Watanabe, Akihide Kuwabara, Haq Nawaz, Nur Ika Puji Ayu, Masao Yonemura, Ryoji Kanno, Genki KobayashiHydride (H–) conduction
is a new frontier related
to hydrogen transport in solids. Here, a new H– conductive
oxyhydride Ba2ScHO3 was successfully synthesized
using a high-pressure technique. Powder X-ray and neutron diffraction
experiments investigated the fact that Ba2ScHO3 adopts a K2NiF4-type structure with H– ions preferentially occupying the apical sites, as
supported by theoretical calculations. Electrochemical impedance spectra
showed that Ba2ScHO3 exhibited H– conduction and a conductivity of 5.2 × 10–6 S cm–1 at 300 °C. This value is much higher
than that of BaScO2H, which has an ideal perovskite structure,
suggesting the advantage of layered structures for H– conduction. Tuning site selectivity of H– ions
in layered oxyhydrides might be a promising strategy for designing
fast H– conductors applicable for novel electrochemical
devices.