Surface coordination structure of molybdate with extremely low loading on gamma-alumina characterized by UV resonance Raman spectroscopy

The extremely low loading of molybdate on gamma-Al2O3 (0.1 wt% MoO3/gamma-Al2O3) is characterized by UV resonance Raman spectroscopy. Thanks for the resonance Raman effect, the surface coordination structure of molybdate is well identified. For the first time, the surface octahedral molybdate and the tetrahedral species are detected, even with molybdate loading down to 0.1 wt%. This study suggests that the octahedral molybdate is formed on gamma-Al2O3 at all molybdate loadings. (C) 1999 Academic Press