Size effects on rhodium nanoparticles related to hydrogen-storage capability. Issue 22 (23rd May 2018)

• Record Type: Journal Article
• Authors: Song, Chulho; Yang, Anli; Sakata, Osami; Kumara, L. S. R.; Hiroi, Satoshi; Cui, Yi-Tao; Kusada, Kohei; Kobayashi, Hirokazu; Kitagawa, Hiroshi
• Is Part Of: Physical chemistry chemical physics. Volume 20:Issue 22(2018)
• Page Start: 15183
• Page End: 15191
• Publication Date: 2018-05-23
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c8cp01678j
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : The smallest Rh NPs have the largest structural disorder and volume fraction of cavities and so exhibit excellent hydrogen-storage capacity. Abstract : To unveil the origin of the hydrogen-storage properties of rhodium nanoparticles (Rh NPs), we investigated the electronic and crystal structures of the Rh NPs using various synchrotron based X-ray techniques. Electronic structure studies revealed that the hydrogen-storage capability of Rh NPs could be attributed to their more unoccupied d-DOSs than that of the bulk near the Fermi level. Crystal structure studies indicated that lattice distortion and mean-square displacement increase while coordination number decreases with decreasing particle size and the hydrogen-absorption capability of Rh NPs improves to a greater extent with increased structural disorder in the local structure than with that in the mean structure. The smallest Rh NPs, having the largest structural disorder/increased vacancy spaces and the smallest coordination number, exhibited excellent hydrogen-storage capacity. Finally, from the bond-orientational order analysis, we confirmed that the localized disordering is distributed more over the surface part than the core part and hydrogen can be trapped on the surface part of Rh NPs which increases with a decrease in NP diameter.