The Role of Catalysts in Waste Polymer Upcycling: Recent Developments and Future Trends

The increasing environmental burden of plastic and polymer waste necessitates transformative recycling strategies. This review explores the critical role of catalysts in enabling efficient chemical recycling and upcycling of synthetic and natural polymers with an emphasis on industrial innovations. Emphasizing catalytic depolymerization techniques—such as pyrolysis, gasification, oxidation, hydrocracking, hydrogenolysis, solvolysis, and enzymatic catalysis—the paper highlights recent advances in catalyst design and reactor technologies. This research highlights the interplay between polymer structure and catalyst selection, demonstrating how variations in backbone chemistry can shape catalytic pathways and ultimately affect material performance. Key developments include the use of metal-zeolite systems, metal-organic frameworks (MOFs), hybrid chemo-enzymatic pathways, and AI-optimized processes for selective and scalable conversion of plastic waste. The study outlines the potential of catalytic systems to enhance resource circularity by converting mixed or contaminated waste streams into valuable monomers, fuels, and chemicals. Emerging trends in AI-driven catalyst discovery and process optimization are also examined, positioning catalysis at the forefront of sustainable polymer waste management and circular economy innovation. Organized by depolymerization mechanism to highlight key catalytic pathways, this review integrates representative industrial applications to illustrate both recent breakthroughs and the varying technological maturity of scalable chemical recycling strategies for converting complex waste streams into valuable products.