ETHENE ADSORPTION AND REACTION ON SOME ZEOLITES AND PILLARED CLAYS

In the acidic solids used in this study, ethene undergoes a cationic p olymerisation started by proton transfer. The larger the dimensions of the micropores, the higher is the degree of branching of the polymeri c cationic species obtained. Such saturated polymeric cationic species evolve upon thermal treatment by loss of hydrogen to allylic carbocat ions (linear mono-, di- and trienic species as well as penta-cyclo and hexa-cyclo monoenic species), which are precursors to aromatics. All species have been characterised both in the infrared (IR) and ultravio let (UV) regions. The overall chemistry is very close to that of prope ne on the same systems, though ethene appears less reactive.