G. Saggio, M. Taoufik, J.-M. Basset, J. Thivolle-Cazat
ChemCatChem, volume 2, issue 12, pp. 1594-1598, (2010)
Only 50 % of the silica-supported tantalum hydride sites are active in
the metathesis of propane. Indeed, more than 45 % of the tantalum
hydride can be eliminated by a selective oxygen poisoning of inactive
sites with no significant decrease in the global turnover. Conversely,
cyclopentane induces no such selective poisoning. Hence, the active
tantalum hydride sites that show greater resistance to oxygen poisoning
correspond to the νTaH bands of higher wavenumbers, particularly that at 1860 cm−1.
These active tantalum hydride sites should correspond to tris- or
monohydride species relatively far from silica surface oxygen atoms.