Direct propene oxidation with molecular O-2 was performed at 428 K under at
mospheric pressure over titanium sulfate-modified zirconia (STi/Z) and sulf
ated-zirconia (SZ) catalysts, which were prepared by direct impregnation of
Ti-IV sulfate and ammonium sulfate solution onto amorphous zirconia, respe
ctively. The 7.5%STi/Z catalyst exhibited the highest propene conversion (5
.6%) under the experimental conditions. C-3-Oxygenates such as propene oxid
e (PO) and acetone were detected as products with C-4-C-6 hydrocarbons. The
catalytic performances depended on the amounts of surface sites for NH3 ad
sorption, which could be associated with sulfate content, calcination tempe
rature and reaction time. Molecular oxygen forms oxygenates, and reduces ca
rbonaceous deposits.