Iodine Catalyzed Propane Oxidative Dehydrogenation Using Dibromomethane as an Oxidant

Propane oxidative dehydrogenation is a promising candidate for on-purpose propylene production. However, in oxidative dehydrogenation the propylene yield is limited by the simultaneous oxidization of propane to multiple oxygenated byproducts. We show that a small amount of I2 is highly effective in catalyzing the dehydrogenation of propane into propylene, using dibromomethane (DBM), a byproduct of the activation of methane by bromine, as the oxidant. Single-pass “C3H6+C3H7X” (X = Br, I; C3H7X can be easily converted to C3H6 and HX) yields of up to 80% can be easily achieved, with the highly selective conversion of DBM to methyl bromide, which is readily converted into either high-market-value petrochemicals or liquid fuels. Bearing in mind that the formation of DBM is one of the major undesirable byproducts in the bromine-mediated gas-to-liquid technology, our findings create a win-win situation. On the one hand, this approach is promising for developing a low-cost, on-purpose propylene technology using natural gas as a feedstock. On the other hand, DBM is shown to be a useful reactant for the industrial application of the bromine-mediated gas-to-liquid technology.