Investigation of microstructure and hydrogen absorption properties of bulk immiscible AgRh alloy nanoparticles

JOURNAL OF ALLOYS AND COMPOUNDS

卷:869

Article

Tayal, Akhil¹  Seo, Okkyun²  Kim, Jaemyung²  Kusada, Kohei³  Kobayashi, Hirokazu³  Kitagawa, Hiroshi³  Sakata, Osami^2,4,5 

[1] DESY, Notkestr 85, D-22607 Hamburg, Germany

[2] Natl Inst Mat Sci, Res Ctr Adv Measurement & Characterizat, Synchrotron Xray Grp, 1-1-1 Kouto, Sayo, Hyogo 6795148, Japan

[3] Kyoto Univ, Grad Sch Sci, Div Chem, Sakyo Ku, Kitashirakawa Oiwake Cho, Kyoto 6068502, Japan

[4] Tokyo Inst Technol, Dept Mat Sci & Engn, Midori Ku, Yokohama, Kanagawa 2268502, Japan

[5] Japan Synchrotron Radiat Res Inst JASRI, Ctr Synchrotron Radiat Res, 1-1-1 Kouto, Sayo, Hyogo 6795198, Japan

关键词: Ag-Rh alloy nanoparticles;    XAFS;    Hydrogen absorption;    Heterogeneous alloy;   

DOI  :  10.1016/j.jallcom.2021.159268

来源: Elsevier

【 摘 要 】

Bimetallic alloy nanoparticles (NPs) exhibit superior catalytic and chemical storage properties relative to the monometallic NPs. Previously, it has been reported that bimetallic AgRh forms solid-solution alloy NPs that have unusual hydrogen storage properties not commonly observed in individual Ag and Rh NPs. Here, we use a combination of X-ray diffraction (XRD) and X-ray absorption fine structure spectroscopy (XAFS) techniques to investigate the microstructure and unique hydrogen absorption properties of bulk immiscible AgRh alloy NPs. XRD analysis reveals that the long-range structure of the alloy sample can be estimated as a single fcc phase with a slightly smaller lattice parameter than that of the bulk Ag and larger than that of bulk Rh. XAFS analysis reveals that charge transfer between Rh and Ag occurs in this interfacial region. The near-edge profile reveals a variety of local environments for Ag and Rh, including distinct atomic pair distances and disorder. The atomic pair distances were compressed around Ag and elongated around Rh. A substantial fraction of the sample is an alloy phase formed by mixing of nano/sub-nanosized domains of Rh and Ag NPs. Mixing at the atomic level mainly occurs in the interfacial region. Consequently, the interfacial region has an important influence over the microstructure and provides active sites for hydrogen absorption. (C) 2021 The Authors. Published by Elsevier B.V.

【 授权许可】

Free