| abstract |
A catalyst is provided, which is especially applicable for the selective production of certain desired hydrocarbons, comprising a crystalline aluminosilicate zeolite having a silica to alumina ratio of at least about 12, a constraint index, as hereinafter defined, within the approximate range of 1 to 12 and having contained within the interior crystalline structure thereof added amorphous silica in an amount of at least about 0.1 and preferably between about 2 and about 10 weight percent. The invention described herein also encompasses synthesis of the specified catalyst and use of the same in selectively producing low molecular weight olefins and/or para-xylene from appropriate charge stocks. |