TY - JOUR
T1 - Theoretical study of tetrahedral site occupation by hydrogen in Pd nanoparticles
AU - Ishimoto, Takayoshi
AU - Koyama, Michihisa
N1 - Funding Information:
This work was supported by CREST, and ACCEL, JST, and the Advanced Computational Scientific Program of the Research Institute for Information Technology, Kyushu University. The activities of the Advanced Automotive Research Laboratory, Hiroshima University, are supported by Mazda Motor Corporation. The activities of the INAMORI Frontier Research Center, Kyushu University, are supported by Kyocera Corporation.
Publisher Copyright:
© 2018 Author(s).
PY - 2018/1/21
Y1 - 2018/1/21
N2 - To understand the enhanced effects and new hydrogen absorption properties of metal nanoparticles, we theoretically investigated the hydrogen absorption in Pd nanoparticles, adopting the Pd405 model of ca. 2.5 nm by using density functional theory. Pd405 showed inhomogeneous geometric features, especially near the surface region. The hydrogen absorptions in octahedral (O) and tetrahedral (T) sites near the core region were stable and unstable, respectively, similar to the Pd bulk. We clearly demonstrated the possibility of hydrogen absorption in T sites near the surface of Pd405. The flexible volume change and the difference in hydrogen position relative to the center of mass of the T site that we observed are important factors for stable hydrogen absorption in T sites of Pd nanoparticles. In addition, we discuss the differences in hydrogen diffusion mechanisms in the core and near surface regions, based on the stability of hydrogen absorption in O and T sites.
AB - To understand the enhanced effects and new hydrogen absorption properties of metal nanoparticles, we theoretically investigated the hydrogen absorption in Pd nanoparticles, adopting the Pd405 model of ca. 2.5 nm by using density functional theory. Pd405 showed inhomogeneous geometric features, especially near the surface region. The hydrogen absorptions in octahedral (O) and tetrahedral (T) sites near the core region were stable and unstable, respectively, similar to the Pd bulk. We clearly demonstrated the possibility of hydrogen absorption in T sites near the surface of Pd405. The flexible volume change and the difference in hydrogen position relative to the center of mass of the T site that we observed are important factors for stable hydrogen absorption in T sites of Pd nanoparticles. In addition, we discuss the differences in hydrogen diffusion mechanisms in the core and near surface regions, based on the stability of hydrogen absorption in O and T sites.
UR - http://www.scopus.com/inward/record.url?scp=85041445675&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85041445675&partnerID=8YFLogxK
U2 - 10.1063/1.5005976
DO - 10.1063/1.5005976
M3 - Article
AN - SCOPUS:85041445675
VL - 148
JO - Journal of Chemical Physics
JF - Journal of Chemical Physics
SN - 0021-9606
IS - 3
M1 - 034705
ER -