Catalytic Reductive Conversion of Polyethylene Terephthalate (PET) Plastic Waste into Fuels, Valuable Chemicals and Degradable Polymers

Abstract

Polyethylene terephthalate (PET) is the most widely used synthetic polyester; however, a significant portion of its waste accumulates in landfills, oceans, and incinerators, posing severe environmental and health risks. Chemical recycling and upcycling are promising solutions for post-consumer PET valorization while mitigating plastic pollution. This review summarizes recent advancements in the catalytic reductive conversion of post-consumer PET into fuels, value-added chemicals, and degradable polymers, with a particular focus on heterogeneous catalysis. The catalytic reductive conversion strategies include hydrogenation, hydrogenolysis, hydrodeoxygenation (HDO), and transfer HDO. A variety of products can be obtained depending on the degree of aromatic ring saturation, ester bond hydrogenation, and C-O bond removal. Reaction pathways for achieving target products are outlined. The performance of the developed catalysts is described and compared in each section. In addition, the role of active sites, structure-activity relationships, and reaction mechanisms are comprehensively discussed. Finally, future perspectives are proposed, with specific emphasis on one-pot tandem processes, non-noble metal catalyst design, new chemical production, the impact of additives, elucidation of reaction networks and mechanistic studies. This review aims to inspire innovative solutions for sustainable PET waste management through advanced catalytic reductive technologies.