Preparation, Characterization, and Catalytic Properties of Tungsten Trioxide Cyclic Trimers on FeO(111)/Pt(111)

Journal Article · Thu Jan 12 00:00:00 EST 2012 · Journal of Physical Chemistry C

DOI:https://doi.org/10.1021/jp2093324· OSTI ID:1036062

Li, Shao-Chun; Li, Zhenjun; Zhang, Zhenrong; Kay, Bruce D; Rousseau, Roger J; Dohnalek, Zdenek

The structure and catalytic activity of tungsten oxide clusters formed via sublimation of monodispersed cyclic (WO{sub 3}){sub 3} onto FeO(111)/Pt(111) surface has been studied by a combination of scanning tunneling microscopy (STM), X-ray photoemission spectroscopy (XPS), infrared reflection-absorption spectroscopy (IRAS), temperature programmed desorption (TPD) and density function theory (DFT). After the (WO{sub 3}){sub 3} sublimation, STM images reveal new features composed of three bright maxima arranged in triangular configurations with the distances of {approx}10 {angstrom}. These distances are significantly larger compared to the size of (WO{sub 3}){sub 3} indicating that the clusters dissociated. This conclusion is corroborated by DFT calculations showing that the cluster dissociation into the surface-bound WO{sub 3} monomers is endothermic and kinetically feasible at 300 K. The dissociation is accompanied by significant FeO(111) rearrangements with the Fe ions being pulled on top of the surface and bonded to the WO{sub 3} fragments. Both surface spectroscopies (XPS and IRAS) and calculations indicate that the W ions in the WO{sub 3} monomers remain in (6+) oxidation state and possess terminal W=O groups. Our TPD studies show that this system do not efficiently catalyze alcohol dehydration. This inactivity is explained based on the reaction mechanism calculated by DFT.

• Research Organization: Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1036062
• Report Number(s): PNNL-SA-82959; 30440; KC0302010; TRN: US201205%%579
• Journal Information: Journal of Physical Chemistry C, Vol. 116, Issue 1; ISSN 1932-7447
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ALCOHOLS
DEHYDRATION
DESORPTION
DISSOCIATION
MONOMERS
PHOTOEMISSION
REACTION KINETICS
SCANNING TUNNELING MICROSCOPY
SPECTROSCOPY
SUBLIMATION
TRIANGULAR CONFIGURATION
TUNGSTEN
TUNGSTEN OXIDES
VALENCE
X-RAY PHOTOELECTRON SPECTROSCOPY
Environmental Molecular Sciences Laboratory