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.

在乙烯直接转化为丙烯的过程中，研究了以不同的NiO（PdO）和MoO ₃前体浸渍顺序对多孔氧化铝进行初湿浸渍制备的一系列钼催化剂。在70°C下MoO ₃ / PdO / Al ₂ O ₃达到最大丙烯收率（28 wt。％）通过先后浸入钯前体然后再浸入钼前体获得的催化剂。含有稳定氧化形式的钯或键合在载体镍阳离子表面上的样品在乙烯转化中表现出高活性。发现含钯的催化剂比含镍的催化剂更具选择性，这可能是由于在钯存在下更容易形成还原的活性钼位。