Methylation of Benzene by Methane-13C over Zeolitic Catalysts at 400 .degree.C

An isotopic study utilizing methane- 13 C shows that the product toluene and xylenes formed from its reaction at high pressure (5.5 MPa, 400 °C) with benzene, over Cu/beta and H-beta zeolites, contain substantially methyl- 13 C substituents. It is therefore concluded that direct methylation of benzene with methane is possible under these conditions in a batch reactor. However, a second mechanism can also be recognized in which methylbenzene is formed by fragmentation and rearrangement of benzene without addition of methane gas.