Effects of Solvents and Addition of Metal Oxides on the Liquid Phase Disproportionation of Olefins over MoO3-Al2O3 Catalyst

Abstract

effect of addition of metal oxides to MoO3-Al2O3 as well as the solvent effect of paraffin, aromatics, and naphthenics. By the addition of Cs2O and Tl2O to MoO3-Al2O3 catalyst, the selectivity for disproportionation of olefins increased, showing a tendency similar to that in the gas phase disproportionation reactions. In the presence of linear hydrocarbon solvents, the catalyst life was remarkably enhanced. This tendency was especially intensified in the presence of n-heptane. Disproportionation of propylene in the presence of aromatic or naphthenic hydrocarbons could not be continued for a long time because of the flow resistance in the reactor. In the case of aromatic solvents, large quantities of alkylbenzenes were produced. Infrared spectra of the polymers produced in the presence of various solvents showed absorption bands due to the carbonyl groups. These absorption bands may have resulted from the oxidation of the polymers by the oxygen of the MoO3-Al2O3 catalyst. It is concluded that the reactions in the presence of linear hydrocarbon solvents are prevented from extensive formation of polymers with higher molecular weights.