Previous studies in this laboratory have shown oxygen to be a crucial requirement for the reaction of methane with benzene over zeolite catalysts at 400 degreesC in a high pressure batch reactor. Thus, a two-step mechanism involving the intermediate formation of methanol by partial oxidation of methane followed by the methylation of benzene with methanol in the second step, was postulated. This Paper now shows clearly that there is excellent correlation between the performance of the zeolite catalysts used for the methylation of benzene with methanol in a low pressure flow reactor and the methylation of benzene with methane in the presence of oxygen in a high pressure batch reactor. This finding therefore gives further support to the two-step mechanism for the oxidative methylation reaction at 400 degreesC. (C) 2000 Elsevier Science B.V. All rights reserved.