Papers by Author: Masanori Kohyama

Paper TitlePage

Authors: Masanori Kohyama
Authors: Masanori Kohyama, J. Hoekstra
Authors: Masanori Kohyama, Kenji Tanaka
Authors: Tokuteru Uesugi, Masanori Kohyama, Masahide Kohzu, Kenji Higashi
Authors: Takeo Sasaki, Teruyasu Mizoguchi, Katsuyuki Matsunaga, Shingo Tanaka, Takahisa Yamamoto, Masanori Kohyama, Yuichi Ikuhara
Abstract: Interfacial atomic and electronic structures of Cu/Al2O3(0001) and Cu/Al2O3(11 _ ,20) prepared by a pulsed-laser deposition technique were characterized by high-resolution transmission electron microscopy (HRTEM) and electron energy-loss spectroscopy (EELS). It was found that both systems have O-terminated interfaces, irrespective of different substrate orientations. This indicates that Cu-O interactions across the interface play an important role for the Cu/Al2O3 systems.
Authors: Tokuteru Uesugi, Masanori Kohyama, Kenji Higashi
Authors: K. Okazaki-Maeda, Y. Morikawa, Shingo Tanaka, Masanori Kohyama
Abstract: Pt nano-particles are supported on carbon materials at the electrode catalysts of protonexchange menbrane fuel cells. Pt nano-particles are desirable to be strongly adsorbed on carbon materials for high dispersion, although strong Pt-C interactions may affect the catalytic activity of small clusters. Thus we have examined H-atom absorption on Pt clusters supported or unsupported on graphene sheets, using first-principles calculations. For Pt-atom/graphene systems, a H atom is more weakly adsorbed than for a free Pt atom, and the H-Pt interaction becomes weaker if the interaction between a Pt atom and graphene becomes stronger. For the Ptn-cluster/graphene systems (n=2-4), the H-Pt interactions are also substantially changed from those for free Pt clusters. In the Pt clusters on graphene, the Pt-Pt distances are substantially changed associated with the electronicstructure changes by the Pt-C interactions. These structural and electronic changes in the Pt clusters as well as the presence of graphene itself seem to cause the changes in the absorption energies and preferential sites of H-atom absorption.
Showing 1 to 10 of 29 Paper Titles