Photoelectron spectroscopy of tungsten oxide clusters: Possible molecular models for tungsten oxide surfaces and catalysts


Hua-Jin Zhai, hua-jin.zhai@pnl.gov1, Xin Huang, xin.huang@pnl.gov1, Boggavarapu Kiran, krian@pnl.gov1, Tom Waters1, Jun Li,, David A. Dixon,, and Lai-Sheng Wang, (1) Department of Physics, Washington State University, 2710 University Drive, Richland, WA 99354, (2) W. R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, P.O. Box 999, richland, WA 99352, (3) Department of Chemistry, The University of Alabama, Box 870336, Shelby Hall, Tuscaloosa, AL 35487-0336
We report investigations of the electronic and structural properties and chemical bonding of tungsten oxide clusters via photoelectron spectroscopy and theoretical calculations, which aim at possible mechanistic understanding of tungsten oxide surfaces and catalysts. The key advantage of cluster studies is the flexibility to create clusters with any stoichiometry. Several cluster systems and topics will be presented: (i) W3O8 as a potential molecular model for O-deficient defect sites in tungsten oxides, which readily reacts with O2 to form the peroxide species W3O10; (ii) The d-orbital aromaticity in M3O9- and M3O9(2-) (M = Mo, W); (iii) The unusual charge transfer complex (O2-)WO3+ and superoxide complexes W2O6(O2-) and W3O9(O2-); (iv) sequential oxidation in the W2On- (n = 1-6) series; (v) a comparative study of doubly and singly charged dimetalate anions M2O7(2-), MM'O7(2-), and M2O7- (M, M' = Cr, Mo, W).