LAUSR

Abstract The series of molybdenum catalysts prepared by the incipient wetness impregnation of porous alumina with a different impregnation order of the NiO (PdO) and MoO3 precursors was studied in the direct conversion of ethylene to propylene. The maximum propylene yield (28 wt.%) was achieved at 70 °C MoO3/PdO/Al2O3 catalyst obtained by sequential impregnation of the palladium precursor and then the molybdenum precursor. The samples containing stable oxidized forms of palladium or bonded to the surface of the support nickel cations exhibited a high activity in ethylene conversion. It was found that palladium-containing catalysts were more selective than nickel-containing, probably due to an easier formation of reduced active molybdenum sites in the presence of palladium.