One-pot catalytic conversion of polyethylene wastes to gasoline through a dual-catalyst system

Abstract

Chemical upcycling of polyethylene (PE) waste presents a viable and promising approach to address the issues of plastic waste accumulation. However, developing cost-effective and efficient routes for converting PE waste into value-added products remains a challenging task. Here, we report a one-pot, dual-catalyst system for efficient conversion of PE into gasoline without the need for noble-metal catalysts, external hydrogen, or solvents. A gasoline yield of up to 87% is achieved over a dual-catalyst system comprising WZr-KIT-6 and HZSM-5 at 240°C. The WZr-KIT-6 catalyst facilitated the activation and pre-cracking of PE chains into unsaturated oligomers over Si-O-Zr and W-O(H)-Zr sites. These unsaturated oligomers, characterized by increased mobility and reactivity, were subsequently converted into C₄–C₁₂ gasoline-range compounds through β-scission, isomerization, and hydride transfer over HZSM-5. The synergistic reaction mechanism over mesoporous and microporous materials was crucial for enhancing the efficiency and selectivity of PE conversion.