Cracking of (5-13C)-n-nonane with quartz wool, silica-alumina and type Y zeolite

Abstract

The cracking mechanism of (5-¹³C)-n-nonane has been studied over quartz wool, silica—alumina and a type Y zeolite. The products observed at a reaction temperature of 510°C over quartz wool agree reasonably well with the currently accepted mechanism of free radical cracking. Reaction with silica—alumina at 500°C and zeolite at 230°C results in a ¹³C labelled product distribution which agrees with neither a thermal cracking mechanism nor the currently accepted mechanism of β-scission of carbonium ion intermediates. Rather, the data suggest that the product distribution is a result of the temperature-dependent random desorption and cracking of a complex polymeric precursor.