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Yamasaki T, Iimura S, Kim J, Hosono H. Extremely Shallow Valence Band in Lanthanum Trihydride. J Am Chem Soc 2023; 145:560-566. [PMID: 36542762 DOI: 10.1021/jacs.2c10927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Hydride ions (H-) in solvents are chemically active anions with strong electron-donating ability and are used as reducing agents in organic chemistry. Here, we evaluate the energy level of 1s-electrons in H- accommodated in solid lanthanum hydrides, LaHx (2 ≤ x ≤ 3), by photoemission (ultraviolet photoelectron and photoelectron yield spectroscopies) measurements and density functional theory calculations. We show that a very shallow valance band maximum with an ionization potential of 3.8 eV is attained in LaH3 and that the primary cause is attributed to the small electronegativity of hydrogen and the significant bonding-antibonding interaction between neighboring H-s with a close separation originating from the H-stuffed fluorite-related structure. These results encourage the challenge for p-type conduction in hydride semiconductors and provide a clue to the chemical understanding of polyhydride superconductors.
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Affiliation(s)
- Tomoyuki Yamasaki
- International Research Frontiers Initiative MDX Research Center for Element Strategy, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Soshi Iimura
- International Research Frontiers Initiative MDX Research Center for Element Strategy, Tokyo Institute of Technology, Yokohama 226-8503, Japan.,National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-004, Japan.,PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012, Japan
| | - Junghwan Kim
- International Research Frontiers Initiative MDX Research Center for Element Strategy, Tokyo Institute of Technology, Yokohama 226-8503, Japan.,PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012, Japan
| | - Hideo Hosono
- International Research Frontiers Initiative MDX Research Center for Element Strategy, Tokyo Institute of Technology, Yokohama 226-8503, Japan.,National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-004, Japan
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2
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Chaykina D, Usman I, Colombi G, Schreuders H, Tyburska-Pueschel B, Wu Z, Eijt SWH, Bannenberg LJ, de Wijs GA, Dam B. Aliovalent Calcium Doping of Yttrium Oxyhydride Thin Films and Implications for Photochromism. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2022; 126:14742-14749. [PMID: 36081901 PMCID: PMC9442641 DOI: 10.1021/acs.jpcc.2c04456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 08/12/2022] [Indexed: 06/15/2023]
Abstract
To develop an understanding of the photochromic effect in rare-earth metal oxyhydride thin films (REH3-2x O x , here RE = Y), we explore the aliovalent doping of the RE cation. We prepared Ca-doped yttrium oxyhydride thin films ((Ca z Y1-z )H x O y ) by reactive magnetron cosputtering with Ca doping concentrations between 0 and 36 at. %. All of the films are semiconductors with a constant optical band gap for Ca content below 15%, while the band gap expands for compositions above 15%. Ca doping affects the photochromic properties, resulting in (1) a lower photochromic contrast, likely due to a lower H- concentration, and (2) a faster bleaching speed, caused by a higher pre-exponential factor. Overall, these results point to the importance of the H- concentration for the formation of a "darkened" phase and the local rearrangement of these H- for the kinetics of the process.
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Affiliation(s)
- Diana Chaykina
- Materials
for Energy Conversion and Storage, Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, NL-2629HZ Delft, The Netherlands
| | - Ismene Usman
- Materials
for Energy Conversion and Storage, Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, NL-2629HZ Delft, The Netherlands
| | - Giorgio Colombi
- Materials
for Energy Conversion and Storage, Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, NL-2629HZ Delft, The Netherlands
| | - Herman Schreuders
- Materials
for Energy Conversion and Storage, Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, NL-2629HZ Delft, The Netherlands
| | - Beata Tyburska-Pueschel
- Dutch
Institute for Fundamental Energy Research, De Zaale 20, NL-5612
AJ Eindhoven, The Netherlands
| | - Ziying Wu
- Fundamental
Aspects of Materials and Energy, Department of Radiation Science and
Technology, Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, NL-2629 JB Delft, The Netherlands
| | - Stephan W. H. Eijt
- Fundamental
Aspects of Materials and Energy, Department of Radiation Science and
Technology, Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, NL-2629 JB Delft, The Netherlands
| | - Lars J. Bannenberg
- Materials
for Energy Conversion and Storage, Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, NL-2629HZ Delft, The Netherlands
- Storage
of Electrochemical Energy, Department of Radiation Science and Technology,
Faculty of Applied Sciences, Delft University
of Technology, Mekelweg
15, NL-2629 JB Delft, The Netherlands
| | - Gilles A. de Wijs
- Radboud
University, Institute for Molecules
and Materials, Heyendaalseweg
135, NL-6525 AJ Nijmegen, The Netherlands
| | - Bernard Dam
- Materials
for Energy Conversion and Storage, Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, NL-2629HZ Delft, The Netherlands
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Yiliguma, Park SW, Li J, Sasase M, Kitano M, Hosono H. C 2 Vacancy-Mediated N 2 Activation over Ni-Loaded Rare-Earth Dicarbides for Ammonia Synthesis. ACS Catal 2021. [DOI: 10.1021/acscatal.1c01646] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yiliguma
- Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Sang-Won Park
- Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
- International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Jiang Li
- Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Masato Sasase
- Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Masaaki Kitano
- Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
- Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Hideo Hosono
- Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
- International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
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4
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Hattori M, Iijima S, Nakao T, Hosono H, Hara M. Solid solution for catalytic ammonia synthesis from nitrogen and hydrogen gases at 50 °C. Nat Commun 2020; 11:2001. [PMID: 32332727 PMCID: PMC7181780 DOI: 10.1038/s41467-020-15868-8] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 04/01/2020] [Indexed: 11/30/2022] Open
Abstract
The lack of efficient catalysts for ammonia synthesis from N2 and H2 gases at the lower temperature of ca. 50 °C has been a problem not only for the Haber–Bosch process, but also for ammonia production toward zero CO2 emissions. Here, we report a new approach for low temperature ammonia synthesis that uses a stable electron-donating heterogeneous catalyst, cubic CaFH, a solid solution of CaF2 and CaH2 formed at low temperatures. The catalyst produced ammonia from N2 and H2 gases at 50 °C with an extremely small activation energy of 20 kJ mol−1, which is less than half that for conventional catalysts reported. The catalytic performance can be attributed to the weak ionic bonds between Ca2+ and H− ions in the solid solution and the facile release of hydrogen atoms from H− sites. Ammonia synthesis via the Haber–Bosch process typically takes place at an elevated temperature in order to achieve a reasonable rate. Here the authors report on a CaFH solid solution with low activation energy for catalytic ammonia synthesis at lower temperatures.
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Affiliation(s)
- Masashi Hattori
- Laboratory for Materials and Structures, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
| | - Shinya Iijima
- Laboratory for Materials and Structures, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
| | - Takuya Nakao
- Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, Kanagawa, 226-8503, Japan
| | - Hideo Hosono
- Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, Kanagawa, 226-8503, Japan.
| | - Michikazu Hara
- Laboratory for Materials and Structures, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan.
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5
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Mizoguchi H, Park SW, Kishida K, Kitano M, Kim J, Sasase M, Honda T, Ikeda K, Otomo T, Hosono H. Zeolitic Intermetallics: LnNiSi (Ln = La–Nd). J Am Chem Soc 2019; 141:3376-3379. [DOI: 10.1021/jacs.8b12784] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hiroshi Mizoguchi
- Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Sang-Won Park
- Laboratory for Materials Research, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Kazuhisa Kishida
- Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Masaaki Kitano
- Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Junghwan Kim
- Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Masato Sasase
- Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Takashi Honda
- Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - Kazutaka Ikeda
- Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - Toshiya Otomo
- Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - Hideo Hosono
- Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
- Laboratory for Materials Research, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
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