title: Role of support-nanoalloy interactions in the atomic-scale structural and chemical ordering for tuning catalytic sites.
abstract: The understanding of the atomic-scale structural and chemical ordering in supported nanosized alloy particles is fundamental for achieving active catalysts by design. This report shows how such knowledge can be obtained by a combination of techniques including X-ray photoelectron spectroscopy and synchrotron radiation based X-ray fine structure absorption spectroscopy and high-energy X-ray diffraction coupled to atomic pair distribution function analysis, and how the support-nanoalloy interaction influences the catalytic activity of ternary nanoalloy (platinum-nickel-cobalt) particles on three different supports: carbon, silica, and titania. The reaction of carbon monoxide with oxygen is employed as a probe to the catalytic activity. The thermochemical processing of this ternary composition, in combination with the different support materials, is demonstrated to be capable of fine-tuning the catalytic activity and stability. The support-nanoalloy interaction is shown to influence structural and chemical ordering in the nanoparticles, leading to support-tunable active sites on the nanoalloys for oxygen activation in the catalytic oxidation of carbon monoxide. A nickel/cobalt-tuned catalytic site on the surface of nanoalloy is revealed for oxygen activation, which differs from the traditional oxygen-activation sites known for oxide-supported noble metal catalysts. The discovery of such support-nanoalloy interaction-enabled oxygen-activation sites introduces a very promising strategy for designing active catalysts in heterogeneous catalysis.
authors.affiliation: Department of Chemistry, State University of New York at Binghamton, Binghamton, New York 13902, USA.
authors.forename: Lefu
authors.initials: L
authors.lastname: Yang
authors.forename: Shiyao
authors.initials: S
authors.lastname: Shan
authors.forename: Rameshwori
authors.initials: R
authors.lastname: Loukrakpam
authors.forename: Valeri
authors.initials: V
authors.lastname: Petkov
authors.forename: Yang
authors.initials: Y
authors.lastname: Ren
authors.forename: Bridgid N
authors.initials: BN
authors.lastname: Wanjala
authors.forename: Mark H
authors.initials: MH
authors.lastname: Engelhard
authors.forename: Jin
authors.initials: J
authors.lastname: Luo
authors.forename: Jun
authors.initials: J
authors.lastname: Yin
authors.forename: Yongsheng
authors.initials: Y
authors.lastname: Chen
authors.forename: Chuan-Jian
authors.initials: CJ
authors.lastname: Zhong