Berry, Frank J.; Derrick, Glyn R.; Marco, José F. and Mortimer, Michael
Silica-supported silicotungstic acid: A study by X-ray photoelectron spectroscopy.
Materials Chemistry and Physics, 114(2-3) pp. 1000–1003.
W 4f and O 1s X-ray photoelectron spectra for silicotungstic acid, H4SiW12O40, in pure and silica-supported form are reported. W 4f XP spectra for the supported acid are analysed in terms of contributions from two W(VI) spin–orbit doublets arising from tungsten atoms in terminal WO bonds some of which directly interact with the silica surface. At low loading (3.2 wt.%) significant changes in the relative contributions and binding energies of the two spin–orbit doublets are taken as evidence of a strong interaction of individual [SiW12O40]4− anions with highly active sites on the silica surface. It is suggested that selective ordering of silanol groups can occur on the silica surface in order to accommodate the adsorption of individual [SiW12O40]4− anions.
Actions (login may be required)