A method of preparing a xylene product is carried out by providing a
reactor containing a non-steamed, phosphorus-treated ZSM-5-type zeolite
catalyst. The catalyst is contacted with a toluene/methanol feed and a
cofeed of hydrogen under reactor conditions suitable for the methylation
of toluene. Water is introducing into the reactor during the methylation
reaction under conditions that provide substantially no structural
aluminum loss of the catalyst from such introduction of water.