Nanocatalytic upcycling of plastic waste: Advances in selective conversion technologies for sustainable high-value products recovery

Plastics such as polyethylene terephthalate (PET), polystyrene (PS), polyvinyl chloride (PVC), polypropylene (PP), and polyethylene (PE) are indispensable in modern society, with global production exceeding 460 million metric tons annually and projected to nearly double by 2050. However, their extensive use generates severe environmental challenges: only ∼9 % of plastic waste is recycled, 19–23 million tons enter aquatic ecosystems each year, and associated environmental and social costs are estimated at USD 300–460 billion annually. Conventional waste management methods remain energy-intensive and environmentally damaging. Nanocatalytic chemical upcycling has recently emerged as a promising strategy, converting plastic waste into value-added products such as monomers (e.g., BHET from PET), fuels (gasoline/diesel-range hydrocarbons from PE and PP), aromatics (from PS and PC), hydrogen-rich syngas, and carbon nanomaterials (e.g., CNTs from polyolefins). This review first outlines the current landscape of plastic waste management and then examines advanced nanocatalytic approaches—including pyrolysis, gasification, solvolysis, hydrocracking, photocatalysis, and electrochemical processes—highlighting their efficiencies, limitations, and recent breakthroughs. Particular emphasis is placed on the role of coordination chemistry and rational nanocatalyst design in enhancing selectivity and efficiency. Finally, emerging technologies, challenges, and future opportunities are discussed in the context of advancing a sustainable circular plastics economy.