Insights into structure-performance relationship in the catalytic cracking of high density polyethylene

Zeolite is considered a promising catalyst for plastic cracking because of its well-defined acid sites, high product selectivity, and outstanding stability. The relationship between zeolite structure and catalytic performance is still not well understood. Therefore, on either as prepared or purposely modified ZSM-5 zeolites, we made a systematic investigation of how acid density and pore structure affect catalytic performance in this work. Our results demonstrate that Bronsted acid site density had profound impact on the catalyst lifetime and aromatic selectivity. The relationship between Bronsted acid site density and catalyst lifetime displays a tendency that catalyst life-time declines with acid site density at the beginning, then rises up, instead of a linear correlation. Also, the increase of mesoporosity extends the catalyst lifetime to some extent. This information can give us a better understanding of how to design higher-performance catalysts for chemical upcycling of waste plastics.

Automated summary

This study investigates the effects of acid density and pore structure on the catalytic performance. The results show that the Bronsted acid site density has a profound impact on catalyst lifetime and aromatic selectivity, with a non-linear correlation. Additionally, an increase in mesoporosity extends the catalyst lifetime.