The catalytic properties of zeolite NU-87 were investigated with respect to the disproportionation of 1,2,4-trimethylbenznen and the results were compared to those obtained over H-beta and H-mordentie with 12-membered ring channel system. In the conversion of 1,2,4-trimethylvenzene, the disportionation to xylene and tetramethylbenzene is preferred to the isomerization into 1,2,3- and 1,3,5-isomers over all the three zeolites, but this trend is much more pronounced over HNU-87 owing to its peculiar pore structure. Disproportionation reaction is found to proceed within the micropores of HNU-87, whereas isomerization occurs mainly on the external surface. The high selectivity to disproportionation gives more xylenes and tetramethylbenzenes over HNU-87. The detailed descriptions for the product distribution are also reported.
Hall WK, "The Concentration of Catalytically Active Bronsted Sites on Zeolites" (P.A. Jacobs and R. A. van Santen, Eds.), Stud. Surf. Sci. Catal., Elwevier, Amsterdam, 49, 1253, 1988