Selectivating zeolites with organosiliceous agents

Abstract

There is provided a method for selectivating a zeolite, such as ZSM-5 which may result in functionalization of the zeolite with at least one organosiliceous group of the formula, SiR.sub.n (OX).sub.4-n, where R is at least one hydrocarbyl group, n is 1 or 2 and X is Si or H. This selectivation method involves vapor phase treatment of a zeolite with an organosilicon compound having at least 2 silicon atoms. This organosilicon compound may be a silicone compound, such as hexamethyldisiloxane, or a silane compound such as hexamethyldisilane. This contacting may take place in the presence of hydrogen and an organic carrier. The functionalized zeolites may provide a catalyst which is both highly active and highly selective for converting aromatic hydrocarbons, especially alkylbenzene compounds, to products comprising the para-isomer of dialkylbenzenes. The disproportionation of toluene is an example of such a reaction.

Dependencies are inferred from the claim text.