Plastic waste represents a persistent challenge to environmental sustainability and carbon resource utilization. In real-world products, plastics rarely exist as single, clean polymers; they are often combined with other polymers, additives, pigments, adhesives, fillers and contaminants, making them difficult to recycle through any single technological route.
A Future Views article led by Ding Ma, Academician of the Chinese Academy of Sciences and professor at Peking University in Beijing, China, outlines a graded recycling framework for real-world waste plastics. The article argues that plastic waste should be regarded not as a uniform refuse stream, but as a heterogeneous carbon reservoir whose recovery pathway depends on polymer chemistry, purity, separability, contamination level and degradation history. Clean and separable plastics are most suitable for mechanical recycling, which preserves polymer backbones and minimizes unnecessary carbon loss. By contrast, mixed, aged or contaminated fractions require chemical reconstruction, gasification or biological upgrading to recover their carbon value. By integrating physical, chemical and biological pathways, this framework offers a systems-level strategy to maximize carbon retention, improve recycling efficiency and advance a circular plastics economy.
The team published their future view in Carbon Future on June 25, 2026.
Plastic waste is both a persistent environmental challenge and an underused carbon resource. In real-world products, plastics rarely occur as single, clean polymers; they are commonly combined with other polymers, additives, pigments, adhesives, fillers and contaminants. This complexity makes it difficult to recover their carbon value through any single recycling route.
The article emphasizes that plastic waste should not be treated as a uniform refuse stream, but as a heterogeneous carbon reservoir. Its recycling pathway should instead be guided by polymer chemistry, purity, separability, contamination level and degradation history. Each plastic carbon stream should be directed to the conversion route that best preserves or upgrades its value. Clean and separable plastics are most suitable for recycling strategies that retain polymer backbones, whereas mixed, contaminated or degraded fractions require more selective chemical, thermochemical or biological upgrading.
High-purity PET, PE and PP streams should first be directed to mechanical recycling, including sorting, washing, reprocessing, compatibilization and chain extension. This route retains polymer carbon with relatively low energy input and avoids unnecessary bond cleavage. However, many real-world plastic wastes, including packaging, textiles, automotive plastics and footwear, contain multiple polymer components or residual contaminants, making direct mechanical recycling inefficient or impractical.
For these complex streams, chemical recycling offers a means to reconstruct carbon chains into higher-value products. Solvolysis, catalytic depolymerization, hydrogenolysis, oxidative upgrading, electrified pyrolysis and gasification can convert mixed or aged plastics into monomers, hydrocarbons, waxes, syngas and platform chemicals. Biological upgrading can further complement these approaches, particularly for PET, PLA and oxygenated intermediates generated by chemical pretreatment.
The article also identifies safety as a central design principle for real-world plastic recycling. Halogens, flame retardants, metals, dyes, plasticizers, oils and unknown additives can lead to catalyst poisoning, corrosive emissions, product contamination and secondary environmental risks. Future recycling systems should therefore integrate intelligent sorting, contaminant management, catalyst tolerance, product quality control and life-cycle assessment.
The proposed graded framework organizes mechanical recycling, chemical reconstruction, gasification and biological upgrading as complementary rather than competing strategies. By matching plastic carbon quality with the appropriate recovery pathway, it aims to maximize carbon retention, improve resource circularity and shift plastic recycling from end-of-pipe waste treatment toward product-informed carbon management. The article concludes that the future of plastic recycling will depend not on a universal technology, but on the ability to identify, separate and convert different plastic carbon streams through the right pathway.
This work was supported by the Tencent Foundation through the XPLORER PRIZE and New Cornerstone Investigator Program, the National Natural Science Foundation of China for Excellent Young Scholars (Overseas) (BE3250022).
DOI Link:
https://doi.org/10.26599/CF.2026.9200080
About the Authors
Dr. Tao Zhang is a postdoctoral researcher in the College of Chemistry and Molecular Engineering, Peking University, China. He received his Ph.D. in Engineering from Nankai University in 2025. His research interests focus on Joule-heating catalysis and plastic upcycling. He has published first-author papers in PNAS, Adv. Mater., Angew. Chem. Int. Ed. and other journals.
Dr. Ji Yang is an associate research professor in the group of Academician Ding Ma at Peking University, China. His research interests focus on Joule-heating catalysis and plastic upcycling, particularly the development of innovative catalysts and catalytic processes for addressing energy and environmental challenges. To date, he has published more than 20 papers in Science, Nat. Chem. Eng., Nat. Synth., JACS, Angew. Chem. Int. Ed., and other leading journals.
Prof. Ding Ma is an Academician of the Chinese Academy of Sciences and a professor in the College of Chemistry and Molecular Engineering, Peking University, China. His research interests focus on catalysis for energy and resource conversion, including low-temperature water activation, hydrogen production, hydrogen storage and utilization, and high-value conversion of waste carbon resources. He has made a series of internationally recognized contributions to catalytic science and has received numerous honors, including the Second Prize of the State Natural Science Award, the Xplorer Prize and the New Cornerstone Investigator Program.
https://www.chem.pku.edu.cn/mading/
About Carbon Future
Carbon Future (https://www.sciopen.com/journal/2960-0561) is an open access, peer-reviewed, and international interdisciplinary journal sponsored by Tsinghua University and published by Tsinghua University Press. It serves as a platform for researchers, scientists, and industry professionals to share their findings and insights on carbon-related materials and processes, including catalysis, energy storage and conversion, as well as low carbon emission process and engineering. It features cutting-edge research articles, insightful reviews, perspectives, highlights, and news and views in the field of carbon. The article publishing charge is covered by the Tsinghua University Press. Carbon Future has been indexed by Scopus, Ei compendex, DOAJ, Inspec, CAS…, and it aims at being a leading journal in related fields.
