Ba2ScHO3: H- Conductive Layered Oxyhydride with H- Site Selectivity

Fumitaka Takeiri; Akihiro Watanabe; Akihide Kuwabara; Haq Nawaz; Nur Ika Puji Ayu; Masao Yonemura; Ryoji Kanno; Genki Kobayashi

doi:10.1021/acs.inorgchem.8b03593

Ba₂ScHO₃: H^- Conductive Layered Oxyhydride with H^- Site Selectivity

Inorg Chem. 2019 Apr 1;58(7):4431-4436. doi: 10.1021/acs.inorgchem.8b03593. Epub 2019 Feb 20.

Authors

Fumitaka Takeiri^{1

2}, Akihiro Watanabe^{1

3}, Akihide Kuwabara⁴, Haq Nawaz^{1

2}, Nur Ika Puji Ayu⁵, Masao Yonemura⁵, Ryoji Kanno⁶, Genki Kobayashi^{1

2}

Affiliations

¹ Department of Materials Molecular Science , Institute for Molecular Science , 38 Nishigonaka, Myodaiji , Okazaki , Aichi 444-8585 , Japan.
² SOKENDAI (The Graduate University for Advanced Studies) , 38 Nishigonaka, Myodaiji , Okazaki , Aichi 444-8585 , Japan.
³ Department of Electronic Chemistry, Interdisciplinary Graduate School of Science and Engineering , Tokyo Institute of Technology , 4259 Nagatsuta , Midori , Yokohama 226-8502 , Japan.
⁴ Nanostructures Research Laboratory , Japan Fine Ceramics Center , 2-4-1 Mutsuno , Atsuta , Nagoya 456-8587 , Japan.
⁵ Neutron Science Laboratory (KENS), Institute of Materials Structure Science , High Energy Accelerator Research Organization (KEK) , 203-1 Shirakata , Tokai , Ibaraki 319-1106 , Japan.
⁶ All-Solid-State Battery Unit, Institute of Innovative Research , Tokyo Institute of Technology , 4259 Nagatsuta , Midori , Yokohama 226-8502 , Japan.

PMID: 30784265
DOI: 10.1021/acs.inorgchem.8b03593

Abstract

Hydride (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.