Raman spectroscopic evidence for the existence of 6-molybdoaluminate entities on an Mo/Al2O3 oxidic precursor

A study by Raman spectroscopy of the oxomolybdate surface phase present on an Mo/Al2O3 oxidic precursor reveals the presence of well dispersed 6-molybdoaluminate entities (AlMo6O24H63-) on a 15 wt.% MoO3 oxidic precursor. It is also shown that precipitation of an ammonium 6-molybdoaluminate salt occurs at higher Mo loadings.