title: Correlation between the surface electronic structure and CO-oxidation activity of Pt alloys.
abstract: The surface electronic structure and CO-oxidation activity of Pt and Pt alloys, Pt3T (T = Ti, Hf, Ta, Pt), were investigated. At temperatures below 538 K, the CO-oxidation activities of Pt and Pt3T increased in the order Pt < Pt3Ti < Pt3hHf < Pt3Ta. The center-of-gravity of the Pt d-band (the d-band center) of Pt and Pt3T was theoretically calculated to follow the trend Pt3Ti < Pt3Ta < Pt3Hf < Pt. The CO-oxidation activity showed a volcano-type dependence on the d-band center, where Pt3Ta exhibited a maximum in activity. Theoretical calculations demonstrated that the adsorption energy of CO on the catalyst surface monotonically decreases with the lowering of the d-band center because of diminished hybridization of the surface d-band and the lowest-unoccupied molecular orbital (LUMO) of CO. The observed volcano-type correlation between the d-band center and the CO oxidation activity is rationalized in terms of the CO adsorption energy, which counterbalances the surface coverage by CO and the rate of CO oxidation.
authors.affiliation: National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan. ABE.Hideki@nims.go.jp GUBBALA.Venkataramesh@nims.go.jp.
authors.forename: Hideki
authors.initials: H
authors.lastname: Abe
authors.forename: Hideki
authors.initials: H
authors.lastname: Yoshikawa
authors.forename: Naoto
authors.initials: N
authors.lastname: Umezawa
authors.forename: Ya
authors.initials: Y
authors.lastname: Xu
authors.forename: Govindachetty
authors.initials: G
authors.lastname: Saravanan
authors.forename: Gubbala V
authors.initials: GV
authors.lastname: Ramesh
authors.forename: Toyokazu
authors.initials: T
authors.lastname: Tanabe
authors.forename: Rajesh
authors.initials: R
authors.lastname: Kodiyath
authors.forename: Shigenori
authors.initials: S
authors.lastname: Ueda
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Sekido
authors.forename: Yoko
authors.initials: Y
authors.lastname: Yamabe-Mitarai
authors.forename: Masahiko
authors.initials: M
authors.lastname: Shimoda
authors.forename: Takahisa
authors.initials: T
authors.lastname: Ohno
authors.forename: Futoshi
authors.initials: F
authors.lastname: Matsumoto
authors.forename: Takayuki
authors.initials: T
authors.lastname: Komatsu