Catalytic partial oxidation of propylene to acrolein: The activity of bismuth molybdate catalysts under oxygen-rich conditions

The effect of Bi/Mo ratio, which varied between 1:3 and 2:1, on the activity of bismuth molybdate catalysts prepared by precipitation method for partial oxidation of propylene has been investigated. X-ray diffraction analysis revealed that the catalysts contained a mixture of α-Bi ₂Mo₃O₁₂ and molybdite (MoO₃) for Bi/Mo = 1:3, pure α-Bi₂Mo₃O₁₂ for Bi/Mo = 2:3, a mixture of α-Bi₂Mo₂O₉ and α-Bi₂Mo₃O₁₂ for Bi/Mo = 1:1, and pure γ-Bi₂MoO₆ for Bi/Mo = 2:1. The catalytic activity tests show that the catalysts achieved up to 56% conversion of C ₃H₆ with up to 91% selectivity towards C₃H ₄O production. The relative reactivity of the catalysts follow the order of Bi/Mo 2:3 ≈ Bi/Mo 2:1 > Bi/Mo 1:3 > Bi/Mo 1:1.