Selective Bromination of Methane Over Solid Acid Catalysts and Poly (4-vinyl pyridine) Catalyzed Hydrolysis and Methanolysis of Methyl Bromide

The direct conversion of methane to methanol remains a big challenge for the scientific community. The large scale production of methanol is still achieved through the high temperature and capital intensive steam reforming of methane to synthesis gas followed by the reduction of CO under pressure. Several routes have been explored in the conversion of methane to valuable chemicals. Among these routes halogenation has been considered as an alternative way to transform methane to methanol/dimethyl ether via the hydrolysis of the methyl halide. Because bromination is slightly exothermic and more selective than chlorination and hydrogen bromide can be easily oxidized to bromine, we carried out bromination of methane with bromine over various solid acids under flow conditions. Methyl bromide selectivity ranging from 70% to 100% was obtained. Methyl bromide was subsequently transformed to methanol/dimethyl ether using poly (4-vinyl pyridine) as catalyst and acid scavenger under moderate reaction conditions (100 °C, 8 bar).