Editor's choice paperThe effective silylation of external surface on H-ZSM5 with cyclic siloxane for the catalytic cracking of naphtha

- The durability of H-ZSM5 for the catalytic cracking of naphtha was improved by silylation with cyclic siloxanes.
- Silylated H-ZSM5 showed less reactivity for 1,3,5-triisopropylbenzene, while maintaining the activity for hexane cracking.
- IR analysis revealed the advantage of cyclic siloxanes to deactivate acid sites on external surface on H-ZSM5 zeolite.

Acid sites existing on the external surface of zeolites are the main cause of the formation of coke materials, resulting in decreasing the catalytic activity. For the durability of the reaction, silylation of external acid sites was adopted. Among various silylation reagents, cyclic siloxanes were effective silylation compounds for the deactivation of the acid sites on external surface on zeolite without prohibiting the objective reaction, cracking of naphtha. The effect of silylation was confirmed not only by the reaction but also by infra-red analysis.