Scaling up chemical recycling: High-yield polyolefin pyrolysis to liquid hydrocarbons using iron single atom catalysts

The chemical recycling of polyolefins (PO) via pyrolysis offers a circular pathway for plastic waste management, yet industrial implementation remains hindered by high energy demands and poor product selectivity. Here, we report an Fe-catalyzed pyrolysis process that achieves 97% PO conversion and a 94% yield of C6 to C35 liquid hydrocarbons. By using a zeolitic imidazolate framework (ZIF)–derived, N-doped porous carbon-supported iron single-atom catalyst (Fe 1 @NC) in combination with a strategic temperature gradient control, we overcome traditional thermolysis limitations. The process was further demonstrated on a kilogram scale, supporting the practical scalability of this catalytic system. Mechanistic investigations reveal that the rate-determining step is an acid base–promoted dehydrogenation of the polymer backbone. Specifically, electronic synergy between the single iron centers and the carbon support stabilizes reactive carbocation intermediates, facilitating their rapid decomposition into high-value olefins and alkanes. These findings provide a scalable and highly efficient catalytic framework for the upcycling of plastic waste into liquid hydrocarbon fractions and chemical feedstocks.