Selective formation of p-xylene in catalytic cracking of low-density polyethylene using simultaneously generated ZSM-5 and mesoporous silica with gel skeletal reinforcement

Silica-coated ZSM-5 with high crystallinity and related hierarchical catalysts using simultaneous generation of ZSM-5 and mesoporous silica with gel skeletal reinforcement exhibited high selectivity for p-xylene among a xylene mixture in catalytic cracking of low-density polyethylene, which reached more than 95%. A linear relationship appeared between mesoporous pore volume and the relative activity per acidic site calculated by the conversion and NH3-TPD, suggesting that the formation of hierarchical structure would increase the activity per active site.