| Abstract: | The larger pore LaY zeolite catalyst resembles homogeneous metal chloride and heterogeneous silica-alumina acid catalysts since the results are consistent with isomerization being a series of intramolecular 1,2 shifts. On the other hand, isomerization with the smaller pore zeolite, ZSM-5, is very different and the relative rate constants appear to be influenced by diffusion and/or shape selectivity. Disproportionation is a significant reaction with LaY but not with ZSM-5 in the temperature range used for the present study. The small amount of trimethylbenzene formed at low conversions using ZSM-5 is 1,2,4-trimethylbenzene, also providing evidence of shape selectivity influencing the reaction products. |
