Disproportionation of 1,2,4-trimethylbenzene over zeolite NU-87

The catalytic properties of zeolite NU-87 were investigated with respect to the disproportion of 1, 2,4-trimethylbenzene and the results were compared to those obtained over H-beta and H-mordenite with 12-membered ring channe l system. In the conversion of 1,2,4-trimethylbenzene, the disproportionati on 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 muc h more pronounced over HNU-87 owing to its peculiar pore structure. Disprop ortionation reaction is found to proceed within the micropores of HNU-87, w hereas isomerization occurs mainly on the external surface. The high select ivity to disproportionation gives more xylenes and tetramethylbenzenes over HNU-87. The derailed descriptions for the product distribution are also re ported.