Catalytic Conversion of Waste Polyethylene Terephthalate to Terephthalic Acid

Against the backdrop of intensifying global plastic pollution and tightening resource and environmental constraints, the efficient recycling of waste polyethylene terephthalate (PET) has become a critical enabler for realizing a circular plastics economy. This article systematically summarizes and evaluates the main technical strategies for the directional catalytic conversion of waste PET into terephthalic acid (TPA). These routes include chemical catalytic depolymerization (acid catalysis, alkali catalysis, electrocatalysis, microwave-assisted processes, and photocatalysis), biocatalytic depolymerization (encompassing specific PET hydrolase-mediated enzymatic degradation and engineered microbial whole-cell catalytic systems). A comparative analysis is conducted on the reaction mechanisms, depolymerization efficiency, process controllability, and scalability potential of each method, along with a critical assessment of recent progress. This review aims to provide theoretical support and technical decision-making references for the high-value utilization of waste PET, monomer-level closed-loop regeneration, and the development of a sustainable plastic industry chain.