The oxidation of benzene to phenol by nitrogen(I) oxide is a recent achievement in the field of gas-phase catalysis. For the first time it was shown to be possible to carry out this reaction over supported vanadium, molybdenum and tungsten oxides [1]. Considerably better results were able to be obtained by using zeolite catalysts [2-4]. Interest in this reaction is particularly great because the introduction of a hydroxyl group into an aromatic ring is a difficult problem in organic synthesis, and the hydroxylation of benzene by nitrous oxide is regarded as the simplest reaction of this type that can be transferred to more complex aromatic compounds.