Upcycling of Waste Plastics into Value-Added Chemicals

Review Upcycling of Waste Plastics into Value-Added Chemicals Jin Xu and Jing Zhang * State Key Laboratory of Chemical Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China * Correspondence: [email protected] Received: 8 November 2024; Revised: 22 January 2025; Accepted: 24 March 2025; Published: 27 March 2025 Abstract: The rapid increase in plastic production has led to a severe plastic waste crisis, driving the development of various recycling technologies to mitigate this growing issue. However, these technologies often encounter substantial economic and environmental challenges in their implementation. An increasingly attractive alternative is chemical upcycling, which can transform waste plastics into value-added chemicals. This review systematically examines upcycling technologies applicable to major commercial plastics, including polyethylene terephthalate (PET), polyolefins, polystyrene (PS), and polyvinyl chloride (PVC). We focus on key strategies such as solvolysis, catalytic pyrolysis, hydrocracking and hydrogenolysis, along with some emerging approaches such as electrocatalysis and photooxidation, aiming to summarize emerging trends in the catalytic chemical upcycling of waste plastics.