Masahiro Ehara 교수

Single-atom catalysts have attracted much interest recently because of their excellent stability, high catalytic activity, and remarkable atom efficiency. Inspired by the recent experimental discovery of a highly efficient single-atom catalyst Pd₁/γ-Al₂O₃, we conducted a comprehensive DFT study on geometries, stabilities and CO oxidation catalytic activities of M₁/γ-Al₂O₃ (M=Pd, Fe, Co, and Ni) by using slab-model. One of the most

We have measured the vibrational structures of the N 1s photoelectron mainline and satellites of the gaseous N2 molecule with the resolution better than 75 meV. The gerade and ungerade symmetries of the core-ionized (mainline) states are resolved energetically, and symmetry-dependent angular distributions for the satellite emission allow us to resolve the Sigma and Pi symmetries of the shake-up (satellite) states. Symmetry-adapted cluster-expansion configuration-interaction calculations of the p

The multiconfiguration time-dependent Hartree (MCTDH) method is applied to rotational and diffractive inelastic molecule-corrugated surface scattering. The molecule is treated as a rigid rotor, hence there are five degrees of freedom included in the calculation. The model systems H2/rectangular lattice and N2/LiF (001) are investigated for scattering with normal incidence. The performance and reliability of the MCTDH method is critically examined with respect to the structure of the MCTDH wave f

The optical activity of a metal nanocluster (NC) is induced either by an asymmetric arrangement of constituents or by a dissymmetric field of a chiral ligand layer. Herein, we unveil the origin of chirality in Ag₂₉ NCs, which is attributed to the intrinsically chiral atomic arrangement. The X-ray crystal structure of a Ag₂₉(BDT)₁₂(TPP)₄ NC (BDT: 1,3-benzenedithiol; TPP: triphenylphosphine) manifested the presence of intrinsic chirality in the outer she

We describe the mechanism, substituent effects, and origins of the selectivity of the nickel-catalyzed four-component coupling reactions of alkyl fluorides, aryl Grignard reagents, and two molecules of 1,3-butadiene that affords a 1,6-octadiene carbon framework bearing alkyl and aryl groups at the 3- and 8-positions, respectively, and the competing cross-coupling reaction. Both the four-component coupling reaction and the cross-coupling reaction are triggered by the formation of anionic nickel c

Density functional theory calculations here elucidated that Cu₃₈-catalyzed NO reduction by CO occurred not through NO dissociative adsorption but through NO dimerization. NO is adsorbed to two Cu atoms in a bridging manner. NO adsorption energy is much larger than that of CO. N-O bond cleavage of the adsorbed NO molecule needs a very large activation energy (Δ<i>G</i>°^‡). On the other hand, dimerization of two NO molecules occurs on the Cu₃₈ surface with small Δ<

Theoretical fine spectroscopy has been performed for the valence ionization spectra of furan, pyrrole, and thiophene with the symmetry-adapted-cluster configuration-interaction general-R method. The present method described that the pi(1) state interacts with the pi(3) (-2)pi*, pi(2) (-2)pi*, and pi(2) (-1)pi(3) (-1)pi* shake-up states providing the split peaks and the outer-valence satellites, both of which are in agreement with the experiments. The intensity distributions were analyzed in deta

The outer- and inner-valence ionization spectra of the Group VI hydrides H2O, H2S and H2Se below the double-ionization threshold were studied by the SAC-CI (symmetry-adapted-cluster configuration-interaction) general-R method. The SAC-CI method quite accurately reproduced the experimental spectra of these hydrides and gave detailed characterizations of the shake-up states. Several unknown satellite peaks were predicted. The shake-up state which includes excitations to the Rydberg orbitals was fo

The 31P MAS NMR spectra of phosphorus-modified chabazite (P-CHA) zeolites have been observed during the hydrothermal treatment to probe the structural changes of phosphorus species in zeolites. Characteristic changes of the spectra were observed in the range of −27 ~ −42 ppm, which correlates to the hydrothermal structure changes in P-CHA zeolites. Theoretical calculations on the 31P and 27Al NMR chemical shifts have been systematically performed to disclose the possible phosphorus species of in