Sustainable Valorization of Polyethylene into Liquid Fuels via Fe ⁰ /USY-Catalyzed Hydropyrolysis: Insights into Catalyst Design and Hydrogenation Mechanisms

High Resolution Image Download MS PowerPoint Slide Hydropyrolysis is a sustainable valorization approach for converting plastic waste into valuable fuels, driven by metal-acid bifunctional catalysts through tandem catalysis under a H 2 atmosphere. This study presents a sustainable resource management approach for converting polyethylene (PE) waste into high-value liquid fuels through Fe 0 /USY-catalyzed hydropyrolysis, with a focus on elucidating catalyst design strategies and hydrogenation mechanisms. The developed Fe 0 /USY bifunctional catalyst synergistically integrates metallic Fe 0 sites for efficient hydrogenation with USY acid sites for controlled cracking, achieving an oil yield of 58.1% rich in C 6 –C 10 hydrocarbons at 500°C. The Fe 0 sites exhibit excellent hydrogenation activity that suppresses coke formation by converting alkene intermediates into alkanes under a H 2 atmosphere. Comparative studies under H 2 and N 2 revealed the critical role of H 2 in enhancing oil yield and improving product quality, while mechanistic studies further clarified that H 2 dissociation and hydrogenation occur predominantly on Fe 0 sites, whereas H 2 alone over USY acid sites shows limited hydrogenation activity. These findings provide foundational insights into metal-acid tandem catalysis for plastic valorization and establish Fe 0 /USY as a benchmark system, offering a scalable and economically viable route for sustainable waste-to-fuel conversion within a circular economy framework.