Lj. Lakshmi et Ec. Alyea, ESR, FT-Raman spectroscopic and ethanol partial oxidation studies on MoO3/SnO2 catalysts made by metal oxide vapor synthesis, CATAL LETT, 59(1), 1999, pp. 73-77
A series of SnO2-supported MoO3 catalysts were prepared by the metal oxide
vapor synthesis (MOVS) technique. ESR studies indicated the presence of hig
hly dispersed Mo5+ species in both octahedral and tetrahedral coordination
environments at all the loadings studied. At the highest MoO3 loading of 12
wt%, the formation of MoO3 microcrystallites was indicated from the lower
intensity of the ESR signal. Raman studies also showed the presence of well
dispersed surface molybdate species up to 4.4 wt% MoO3 loading, and the pe
aks corresponding to microcrystallites of molybdena were observed at 12 wt%
MoO3 loading. The ethanol partial oxidation activities of the catalysts in
creased with increase in MoO3 loading and the catalyst with 4.4 wt% molybde
na content showed the highest activity; all the MOVS catalysts showed 100%
selectivity to acetaldehyde at low conversions.