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Tayal A, Seo O, Kim J, Kobayashi H, Yamamoto T, Matsumura S, Kitagawa H, Sakata O. Mechanism of Hydrogen Storage and Structural Transformation in Bimetallic Pd-Pt Nanoparticles. ACS Appl Mater Interfaces 2021; 13:23502-23512. [PMID: 33988965 DOI: 10.1021/acsami.0c22432] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The hydrogen storage capacity of Pd nanoparticles (NPs) decreases as the particles become smaller; however, this reduced capacity is ameliorated by addition of Pt. In the present work, the hydrogen storage mechanism and structural transformations of core (Pd)-shell (Pt) (CS) and solid-solution (SS) NPs during hydrogen absorption and desorption (PHAD) processes are investigated. In situ X-ray absorption spectroscopy measurements were performed to study the evolution of electronic and local structures around Pd and Pt during PHAD. Under ambient conditions, Pd and Pt have distinct local structures. The Pd atomic pairs are more strained in CS NPs than in SS NPs. A similar behavior has been seen in CS NPs after PHAD. The Pd K-edge extended X-ray absorption fine structure data indicate that in CS and SS NPs a substantial fraction of the signal derives from Pd-Pd atomic pairs, indicating that Pd clusters remain present even after PHAD. PHAD causes a rearrangement of the interfacial structure, which becomes homogeneously distributed. The higher coverage of active bimetallic sites results in a higher observed hydrogen storage capacity in the SS phase.
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Affiliation(s)
- Akhil Tayal
- Deutsches Elektronen-Synchrotron, Notkestrasse 85, 22607 Hamburg, Germany
| | - Okkyun Seo
- Synchrotron X-ray Group, Research Center for Advanced Measurement and Characterization, National Institute for Materials Science, 1-1-1 Kouto, Sayo, Hyogo 679-5148, Japan
| | - Jaemyung Kim
- Synchrotron X-ray Group, Research Center for Advanced Measurement and Characterization, National Institute for Materials Science, 1-1-1 Kouto, Sayo, Hyogo 679-5148, Japan
| | - Hirokazu Kobayashi
- Division of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Tomokazu Yamamoto
- Department of Applied Quantum Physics and Nuclear Engineering and The Ultramicroscopy Research Center, Kyushu University, Fukuoka 819-0395, Japan
| | - Syo Matsumura
- Department of Applied Quantum Physics and Nuclear Engineering and The Ultramicroscopy Research Center, Kyushu University, Fukuoka 819-0395, Japan
| | - Hiroshi Kitagawa
- Division of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Osami Sakata
- Synchrotron X-ray Group, Research Center for Advanced Measurement and Characterization, National Institute for Materials Science, 1-1-1 Kouto, Sayo, Hyogo 679-5148, Japan
- Department of Materials Science and Engineering, Tokyo Institute of Technology, Nagatsuta, Midori, Yokohama 226-8502, Japan
- Center for Synchrotron Radiation Research, Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1 Kouto, Sayo, Hyogo 679-5198, Japan
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