Elucidating the Spatiotemporal Reaction Mechanism of Polyethylene Aromatization over ZSM-5 Zeolites

The development of zeolite catalysts to simultaneously enhance feed utilization, product selectivity, and stability for polyethylene upgrading has faced challenges due to insufficient understanding of catalyst structure-performance relationships. In this work, we systematically decouple the key structural features of ZSM-5 zeolite—morphology, acidity, and pore architecture—and clarify their specific functions in polyethylene aromatization. We demonstrate that high aromatic yield and stability originate from a dynamic balance between external-surface cracking and internal-channel aromatization. This balance highlights the importance of spatially regulating acid sites and optimizing molecular transport through precise control of zeolite morphology and porosity. By integrating catalyst design, performance evaluation, operando DRIFTS, and online PI-MS, we propose a spatiotemporal reaction pathway that explains the two-stage cascade behavior observed during polyethylene conversion over zeolites. By elucidating the spatiotemporal reaction mechanism of polyethylene aromatization over ZSM-5 zeolites, this study offers guidelines for designing zeolites with improved efficiency in polyethylene selective conversion.