Interaction of alkenes with CoAPO molecular sieves

Photoacoustic spectroscopy of the aluminophosphate molecular sieves CoAPO-5 and CoAPO-11, synthesized hydrothermally using triethylamine and diisopropylamine as template agents, has shown that the amount of cobalt that can be incorporated into the framework is limited to about 0.5 mol%. Electron paramagnetic resonance was used to elucidate radical formation over CoAPO-5 and CoAPO-11 molecular sieves. When alkenes such as cyclohexene, cyclopentene, cyclohexa-1,4-diene and tetramethylethene were adsorbed on the calcined samples, the corresponding organic radicals were formed. They were allyl or cation-type radicals formed via interaction with framework cobalt ions.