Catalyst and process for selective production of para dialkyl substituted benzenes

Abstract From the Canadian patent

A catalyst particularly applicable for the selective production of para dialkyl substituted benzenes is provided comprising a porous crystalline aluminosilicate zeolite which has undergone modification by deposition thereon of a coating of silica extensively covering, and residing substantially exclusively on the external surface thereof as a result of contact with a silicone compound of a molecular size incapable of entering the pores of the zeolite and subsequent heating in an oxygen-containing atmosphere to a temperature in excess of 300°C. but below a temperature at which crystallinity of the zeolite is adversely affected at a rate such that the silicone compound does not volatilize …