Nanosize-induced drastic drop in equilibrium hydrogen pressure for hydride formation and structural stabilization in Pd-Rh solid-solution alloys.
We have synthesized and characterized homogeneous solid-solution alloy nanoparticles of Pd and Rh, which are immiscible with each other in the equilibrium bulk state at around room temperature. The Pd-Rh alloy nanoparticles can absorb hydrogen at ambient pressure and the hydrogen pressure of Pd-Rh alloys for hydrogen storage is dramatically decreased by more than 4 orders of magnitude from the corresponding pressure in the metastable bulk state. The solid-solution state is still maintained in the nanoparticles even after hydrogen absorption/desorption, in contrast to the metastable bulks which are separated into Pd and Rh during the process.
Division of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, Japan. hkobayashi@kuchem.kyoto-u.ac.jp
Hirokazu
H
Kobayashi
Hitoshi
H
Morita
Miho
M
Yamauchi
Ryuichi
R
Ikeda
Hiroshi
H
Kitagawa
Yoshiki
Y
Kubota
Kenichi
K
Kato
Masaki
M
Takata
Shoichi
S
Toh
Syo
S
Matsumura