title: Reaction Mechanism of the Multiple-Electron Oxygen Reduction Reaction on the Surfaces of Gold and Platinum Nanoparticles Loaded on Titanium(IV) Oxide.
abstract: Au and Pt nanoparticles with varying mean particle size and comparable loading amounts were loaded on the surface of TiO2(Au/TiO2and Pt/TiO2, respectively). The photocatalytic activities of Au/TiO2and Pt/TiO2for the oxygen reduction reaction (ORR) in an aerated aqueous solution containing 4% ethanol were compared under ultraviolet-light irradiation at 298 K. The initial rate of H2O2generation (or H2O2formation rate) in the Au/TiO2system is much greater than that in the Pt/TiO2system regardless of the metal particle size. To clarify the origin for the striking difference in the activity, the photocatalytic ORR on the model slabs (M28/(TiO2)32and M50/(TiO2)96, M = Au and Pt) was simulated by density functional theory (DFT) calculations taking the solvation effect into consideration. The DFT calculations clearly show that regardless of the cluster size, H2O2formation more easily occurs structurally and energetically for the Au/TiO2system, whereas H2O is generated with the O-O bond cleavage in the Pt/TiO2system.
authors.affiliation: Department of Chemistry and Materials Technology, Kyoto Institute of Technology , Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan.
authors.forename: Hisayoshi
authors.initials: H
authors.lastname: Kobayashi
authors.affiliation: Environmental Research Laboratory, Kindai University , 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502, Japan.
authors.forename: Miwako
authors.initials: M
authors.lastname: Teranishi
authors.affiliation: Department of Applied Chemistry, School of Science and Engineering, Kindai University , 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Negishi
authors.affiliation: Environmental Research Laboratory, Kindai University , 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502, Japan.
authors.forename: Shin-Ichi
authors.initials: SI
authors.lastname: Naya
authors.affiliation: Environmental Research Laboratory, Kindai University , 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502, Japan.|Department of Applied Chemistry, School of Science and Engineering, Kindai University , 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502, Japan.
authors.forename: Hiroaki
authors.identifier: http://orcid.org/0000-0001-8638-0697
authors.initials: H
authors.lastname: Tada