Molecular Dynamics Simulation of Zeolite-Assisted Pyrolysis of Polystyrene: Material Selection and Mechanistic Insights.

Polystyrene (PS) presents a significant environmental challenge due to its durability and resistance to degradation. A major issue in addressing this challenge is optimizing the pyrolysis process to selectively convert PS into valuable products, such as styrene, while minimizing unwanted byproducts. Existing studies on PS pyrolysis have primarily focused on general reaction yields and kinetics, with limited molecular-level insight into how zeolites can enhance product selectivity. This study addresses these gaps by investigating zeolite-assisted PS pyrolysis using a combination of reactive molecular dynamics (MD) simulations and Monte Carlo (MC) simulations. We specifically assess how zeolite structure and adsorption properties influence the pyrolysis product distribution, identifying optimal zeolites that enhance styrene yield. Our findings reveal that PS degradation occurs primarily through a chain-breaking mechanism without long-chain re-formation and that zeolites can significantly improve the selectivity and efficiency of the pyrolysis process by selectively adsorbing styrene. This work highlights the potential of zeolite-enhanced pyrolysis as a pathway for sustainable plastic recycling, advancing chemical recycling technologies to tackle plastic waste.