XAFS and XPS study of hydro-/dehydrogenation reaction of Mg-Pd nanoparticles

• Published in: Surface and interface analysis Vol. 46; no. 12-13; pp. 1143 - 1146
• Main Authors: Ogawa, Satoshi, Fujimoto, Taishi, Mizutani, Tsuyoshi, Ogawa, Masahiro, Yogi, Chihiro, Kato, Kazuo, Ohta, Toshiaki, Yoshida, Tomoko, Yagi, Shinya
• Format: Journal Article
• Language: English
• Published: Bognor Regis Blackwell Publishing Ltd 01.12.2014; Wiley Subscription Services, Inc
• Subjects: Dehydrogenation; Gas evaporation method; Hydrogen storage; Hydrogen storage material; Magnesium; Magnesium base alloys; Mg-Pd nanoparticles; Palladium; Phases; X-ray photoelectron spectroscopy; X-rays; XAFS; XPS
• ISSN: 0142-2421; 1096-9918
• DOI: 10.1002/sia.5647

The nanoparticles composed of Mg and Pd atoms (Mg–Pd NPs) have been fabricated by the gas evaporation method, and the variation of the chemical state during hydro‐/dehydrogenations has been investigated by X‐ray photoelectron spectroscopy (XPS) and in‐situ X‐ray absorption fine structure (XAFS) analyses. Both XPS and XAFS spectra have indicated that the Mg–Pd NPs contain the chemical state of the metallic Pd and Mg–Pd alloy phases. The Mg–Pd alloy phase has been identified as MgPd and Mg6Pd by the Pd K‐edge EXAFS analysis. The hydrogen release of the Mg–Pd NPs has not been observed after first hydrogenation due to the migration of Mg toward the surface of the Mg–Pd NPs during the hydrogen storage. This irreversible migration has led the inhibition of the hydrogen diffusion into the surface from the inside of the Mg–Pd NPs. Copyright © 2014 John Wiley & Sons, Ltd.