A Study of the Catalytic Partial Oxidation of Hydrocarbons. XI. The Catalytic Activity of the MoO3–P2O5 and the MoO3–Bi2O3–P2O5 in the Selective Oxidation of Butene, Butadiene, and Furan

Abstract In the present work, the vapor-phase partial oxidation of cis-2-butene, butadiene, furan, and maleic anhydride was carried out over MoO3–P2O5 (1 : 0.2 atomic ratio) and MoO3–Bi2O3–P2O5 (1 : 1 : 0.2) with a contact time of 1.6 sec, at a concentration of 0.6–1.0%, and in air, in order to elucidate the difference between the two catalysts in their catalytic specificity for the oxidation of these reactants to maleic anhydride. Over the MoO3–P2O5 catalyst, the selectivities of butene, butadiene, and furan to maleic anhydride were 13, 50, and 78% respectively. Over the MoO3–Bi2O3–P2O5 catalyst, the formation of maleic anhydride from the reactants was very small, that of CO2 was important, and the rate of maleic anhydride destruction was fairly high. It is considered that the MoO3–Bi2O3–P2O5 catalyst has almost the same catalytic specificity as the MoO3–P2O5 in the C4H8→C4H2O3 step, but that its activity for maleic anhydride destruction is so high that maleic anhydride cannot be accumulated.