Study of the Acid Site Structure on the WO/ZrO Surface

The IR and UV—vis diffuse reflectance spectra of mesoporous WO 3 /ZrO 2 are discussed and a scheme proposed for the acid site structure on the WO 3 /ZrO 2 surface. The high Brönsted acidity of WO 3 /ZrO 2 (H 0 ≤ −11.38) can be explained by the formation of large zirconium polytungstate species such as [≡ Zr 6 1/2+ W 6 6 +O 20 2− ] − H + on the WO 3 /ZrO 2 surface