Kyoto University · Materials Science
Professor Masahiro Ehara's research lab specializes in theoretical and computational chemistry, focusing on the electronic structures, reaction mechanisms, and catalytic properties of nanomaterials and surface systems. Key research directions include single-atom and nanocluster catalysis, particularly in environmentally and industrially relevant reactions such as CO oxidation and NO reduction. The lab employs advanced quantum chemical methods—such as DFT, MCTDH, and configuration interaction calculations—to unravel the origins of catalytic activity, selectivity, and chirality at the atomic level. They also investigate molecular interactions at surfaces, including inelastic scattering and core-level spectroscopy, with a strong emphasis on symmetry and electronic dynamics.
Figures are computed from collected data and may differ slightly.
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 Pd<sub>1</sub>/γ-Al<sub>2</sub>O<sub>3</sub>, we conducted a comprehensive DFT study on geometries, stabilities and CO oxidation catalytic activities of M<sub>1</sub>/γ-Al<sub>2</sub>O<sub>3</sub> (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 Ag<sub>29</sub> NCs, which is attributed to the intrinsically chiral atomic arrangement. The X-ray crystal structure of a Ag<sub>29</sub>(BDT)<sub>12</sub>(TPP)<sub>4</sub> 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 Cu<sub>38</sub>-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>°<sup>‡</sup>). On the other hand, dimerization of two NO molecules occurs on the Cu<sub>38</sub> 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
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