A study of the hydrogenation property investigated by the electronic states of transition metals

2015 Fiscal Year Final Research Report

• Project/Area Number: 25420756
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Structural/Functional materials
• Research Institution: Hiroshima University
• Principal Investigator: Ishimatsu Naoki 広島大学, 理学(系)研究科(研究院), 助教 (70343291)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 金属水素化物 / パラジウム / X線吸収分光法 / 電子状態

Outline of Final Research Achievements

Hydrogenation of Pd-TM alloys (TM=Ru, Rh, Ag, and Au) is investigated in terms of the electronic states of the alloys. For this purpose, the electronic states before and after hydrogenation have been probed by X-ray absorption spectroscopy (XAS) at the L2,3-edges. The relationship between the element-selective electronic structure and thermodynamic hydrogenation property has been discussed. Spectral changes near the absorption edge demonstrate that both Pd and TM atoms bond with H atoms in the Pd-TM (TM=Ru, Rh) alloys, whereas only Pd atoms bond with H atoms and the TM-H bond is absent in the case of Pd-TM (TM=Ag, Au) alloys. Therefore, the hydrogenation effect on the d electronic state differs between TMs with fully occupied and partially occupied d shells. The thermodynamic hydrogenation property of Pd-TM alloys is interpreted by the appearance of TM-H bond and lattice expansion or compression with respect to the lattice constant of the Pd metal.

Free Research Field

X線吸収分光法を用いた物性研究