The partial oxidation of some cyclohexenes and branched chain olefins over a silver catalyst

The oxidation of some cyclic and branched chain olefins over a silver catalyst effective for the conversion of ethylene to ethylene oxide has been investigated in a steady state flow system. The reaction of cyclohexene produces benzene and that of both 1-methylcyclohexene and 4-methylcyclohexene yields toluene. The selectivity to aromatics exceeds 20% for fractional conversions below 0.2, but it can be improved to almost 50% by inclusion of an optimum quantity of dichloroethane in the feed. Styrene is oxidised more slowly than the cyclohexenes and only carbon dioxide and water are produced. The oxidation of 3,3-dimethyl-1-butene and 3-methyl-1-butene occurs much faster than that of the cyclic molecules and some of the corresponding epoxides are produced. The selectivity with the dimethyl-butene is 9-13% for conversions to 0.2. The methylbutene requires a higher temperature for reaction and the epoxide yield is lower. Factors influencing reactivity and product distribution are discussed.