Downloads

Xu, J., & Zhang, J. Upcycling of Waste Plastics into Value-Added Chemicals. Science for Energy and Environment. 2025, 2(1), 4. doi: https://doi.org/10.53941/see.2025.100004

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: jingzhang8507@ecust.edu.cn

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.

Keywords:

plastics chemical upcycling added value chemicals

References

  1. Sardon, H.; Dove, A.P. Plastics recycling with a difference. Science 2018, 360, 380–381. doi: 10.1126/science.aat4997
  2. Plastics–The Facts. Available online: https://plasticseurope.org/knowledge-hub/plastics-the-facts-2022/ (accessed on 27 October 2024).
  3. Geyer, R.; Jambeck, J.R.; Law, K.L. Production, use, and fate of all plastics ever made. Sci. Adv. 2017, 3, e1700782. doi: 10.1126/sciadv.1700782
  4. Global Plastics Outlook. Available online: https://www.oecd.org/en/publications/2022/06/global-plastics-outlook_f065ef59.html (accessed on 27 October 2024).
  5. MacLeod, M.; Arp, H.P.H.; Tekman, M.B.; Jahnke, A. The global threat from plastic pollution. Science 2021, 373, 61–65. doi: 10.1126/science.abg5433
  6. Stubbins, A.; Law, K.L.; Muñoz, S.E.; Bianchi, T.S.; Zhu, L. Plastics in the Earth system. Science 2021, 373, 51–55. doi: 10.1126/science.abb0354
  7. Pan, Q.; Liu, Q.-Y.; Zheng, J.; Li, Y.-H.; Xiang, S.; Sun, X.-J.; He, X.-S. Volatile and semi-volatile organic compounds in landfill gas: Composition characteristics and health risks. Environ. Int. 2023, 174, 107886. doi: 10.1016/j.envint.2023.107886
  8. He, X.-S.; Pan, Q.; Xi, B.-D.; Zheng, J.; Liu, Q.-Y.; Sun, Y. Volatile and semi-volatile organic compounds in landfill leachate: Concurrence, removal and the influencing factors. Water Res. 2023, 245, 120566. doi: 10.1016/j.watres.2023.120566
  9. Vlasopoulos, A.; Malinauskaite, J.; Żabnieńska-Góra, A.; Jouhara, H. Life cycle assessment of plastic waste and energy recovery. Energy 2023, 277, 127576. doi: 10.1016/j.energy.2023.127576
  10. Vollmer, I.; Jenks, M.J.F.; Roelands, M.C.P.; White, R.J.; van Harmelen, T.; de Wild, P.; van der Laan, G.P.; Meirer, F.; Keurentjes, J.T.F.; Weckhuysen, B.M. Beyond Mechanical Recycling: Giving New Life to Plastic Waste. Angew. Chem. Int. Ed. 2020, 59, 15402–15423. doi: 10.1002/anie.201915651
  11. Verma, R.; Vinoda, K.S.; Papireddy, M.; Gowda, A.N.S. Toxic Pollutants from Plastic Waste- A Review. Procedia Environ. Sci. 2016, 35, 701–708. doi: 10.1016/j.proenv.2016.07.069
  12. Rahimi, A.; García, J.M. Chemical recycling of waste plastics for new materials production. Nat. Rev. Chem. 2017, 1, 0046. doi: 10.1038/s41570-017-0046
  13. The New Plastics Economy: Rethinking the Future of Plastics. Available online: https://www.ellenmacarthurfoundation.org/the-new-plastics-economy-rethinking-the-future-of-plastics (accessed on 27 October 2024).
  14. Barnard, E.; Rubio Arias, J.J.; Thielemans, W. Chemolytic depolymerisation of PET: A review. Green Chem. 2021, 23, 3765–3789. doi: 10.1039/D1GC00887K
  15. Faust, K.; Denifl, P.; Hapke, M. Recent Advances in Catalytic Chemical Recycling of Polyolefins. ChemCatChem 2023, 15, e202300310. doi: 10.1002/cctc.202300310
  16. Marquez, C.; Martin, C.; Linares, N.; De Vos, D. Catalytic routes towards polystyrene recycling. Mater. Horiz. 2023, 10, 1625–1640. doi: 10.1039/D2MH01215D
  17. Jiang, X.; Zhu, B.; Zhu, M. An overview on the recycling of waste poly(vinyl chloride). Green Chem. 2023, 25, 6971–7025. doi: 10.1039/D3GC02585C
  18. Sajwan, D.; Sharma, A.; Sharma, M.; Krishnan, V. Upcycling of Plastic Waste Using Photo-, Electro-, and Photoelectrocatalytic Approaches: A Way toward Circular Economy. ACS Catal. 2024, 14, 4865–4926. doi: 10.1021/acscatal.4c00290
  19. Hou, Q.; Zhen, M.; Qian, H.; Nie, Y.; Bai, X.; Xia, T.; Laiq Ur Rehman, M.; Li, Q.; Ju, M. Upcycling and catalytic degradation of plastic wastes. Cell Rep. Phys. Sci. 2021, 2, 100514. doi: 10.1016/j.xcrp.2021.100514
  20. Ragaert, K.; Delva, L.; Van Geem, K. Mechanical and chemical recycling of solid plastic waste. Waste Manag. 2017, 69, 24–58. doi: 10.1016/j.wasman.2017.07.044
  21. Chen, H.; Wan, K.; Zhang, Y.; Wang, Y. Waste to Wealth: Chemical Recycling and Chemical Upcycling of Waste Plastics for a Great Future. ChemSusChem 2021, 14, 4123–4136. doi: 10.1002/cssc.202100652
  22. Li, X.; Wang, J.; Zhang, T.; Yang, S.; Sun, M.; Qian, X.; Wang, T.; Zhao, Y. Sustainable catalytic strategies for the transformation of plastic wastes into valued products. Chem. Eng. Sci. 2023, 276, 118729. doi: 10.1016/j.ces.2023.118729
  23. Chen, X.; Wang, Y.; Zhang, L. Recent Progress in the Chemical Upcycling of Plastic Wastes. ChemSusChem 2021, 14, 4137–4151. doi: 10.1002/cssc.202100868
  24. Kosloski-Oh, S.C.; Wood, Z.A.; Manjarrez, Y.; de los Rios, J.P.; Fieser, M.E. Catalytic methods for chemical recycling or upcycling of commercial polymers. Mater. Horiz. 2021, 8, 1084–1129. doi: 10.1039/D0MH01286F
  25. Di, J.; Reck, B.K.; Miatto, A.; Graedel, T.E. United States plastics: Large flows, short lifetimes, and negligible recycling. Resour. Conserv. Recycl. 2021, 167, 105440. doi: 10.1016/j.resconrec.2021.105440
  26. Smith, R.L.; Takkellapati, S.; Riegerix, R.C. Recycling of Plastics in the United States: Plastic Material Flows and Polyethylene Terephthalate (PET) Recycling Processes. ACS Sustain. Chem. Eng. 2022, 10, 2084–2096. doi: 10.1021/acssuschemeng.1c06845
  27. Directives 2008/98/EC of the European Parliament and of the Council of 19 November 2008 on Waste and Repealing Certain Directives. Available online: https://eur-lex.europa.eu/eli/dir/2008/98/oj (accessed on 27 October 2024).
  28. Kabir, E.; Kaur, R.; Lee, J.; Kim, K.-H.; Kwon, E.E. Prospects of biopolymer technology as an alternative option for non-degradable plastics and sustainable management of plastic wastes. J. Clean. Prod. 2020, 258, 120536. doi: 10.1016/j.jclepro.2020.120536
  29. Lettner, M.; Schöggl, J.-P.; Stern, T. Factors influencing the market diffusion of bio-based plastics: Results of four comparative scenario analyses. J. Clean. Prod. 2017, 157, 289–298. doi: 10.1016/j.jclepro.2017.04.077
  30. Zhao, X.; Cornish, K.; Vodovotz, Y. Narrowing the Gap for Bioplastic Use in Food Packaging: An Update. Environ. Sci. Technol. 2020, 54, 4712–4732. doi: 10.1021/acs.est.9b03755
  31. Ignatyev, I.A.; Thielemans, W.; Vander Beke, B. Recycling of Polymers: A Review. ChemSusChem 2014, 7, 1579–1593. doi: 10.1002/cssc.201300898
  32. Welle, F. Is PET bottle-to-bottle recycling safe? Evaluation of post-consumer recycling processes according to the EFSA guidelines. Resour. Conserv. Recycl. 2013, 73, 41–45. doi: 10.1016/j.resconrec.2013.01.012
  33. Saikrishnan, S.; Jubinville, D.; Tzoganakis, C.; Mekonnen, T.H. Thermo-mechanical degradation of polypropylene (PP) and low-density polyethylene (LDPE) blends exposed to simulated recycling. Polym. Degrad. Stab. 2020, 182, 109390. doi: 10.1016/j.polymdegradstab.2020.109390
  34. Suzuki, G.; Uchida, N.; Tanaka, K.; Higashi, O.; Takahashi, Y.; Kuramochi, H.; Yamaguchi, N.; Osako, M. Global discharge of microplastics from mechanical recycling of plastic waste. Environ. Pollut. 2024, 348, 123855. doi: 10.1016/j.envpol.2024.123855
  35. Ellis, L.D.; Rorrer, N.A.; Sullivan, K.P.; Otto, M.; McGeehan, J.E.; Román-Leshkov, Y.; Wierckx, N.; Beckham, G.T. Chemical and biological catalysis for plastics recycling and upcycling. Nat. Catal. 2021, 4, 539–556. doi: 10.1038/s41929-021-00648-4
  36. Guselnikova, O.; Semyonov, O.; Sviridova, E.; Gulyaev, R.; Gorbunova, A.; Kogolev, D.; Trelin, A.; Yamauchi, Y.; Boukherroub, R.; Postnikov, P. “Functional upcycling” of polymer waste towards the design of new materials. Chem. Soc. Rev. 2023, 52, 4755–4832. doi: 10.1039/D2CS00689H
  37. An, W.; Wang, X.-L.; Liu, X.; Wu, G.; Xu, S.; Wang, Y.-Z. Chemical recovery of thermosetting unsaturated polyester resins. Green Chem. 2022, 24, 701–712. doi: 10.1039/D1GC03724B
  38. Zhao, X.; Long, Y.; Xu, S.; Liu, X.; Chen, L.; Wang, Y.-Z. Recovery of epoxy thermosets and their composites. Mater. Today 2023, 64, 72–97. doi: 10.1016/j.mattod.2022.12.005
  39. Ren, T.; Zhan, H.; Xu, H.; Chen, L.; Shen, W.; Xu, Y.; Zhao, D.; Shao, Y.; Wang, Y. Recycling and high-value utilization of polyethylene terephthalate wastes: A review. Environ. Res. 2024, 249, 118428. doi: 10.1016/j.envres.2024.118428
  40. Singh, A.; Rorrer, N.A.; Nicholson, S.R.; Erickson, E.; DesVeaux, J.S.; Avelino, A.F.T.; Lamers, P.; Bhatt, A.; Zhang, Y.; Avery, G.; et al. Techno-economic, life-cycle, and socioeconomic impact analysis of enzymatic recycling of poly(ethylene terephthalate). Joule 2021, 5, 2479–2503. doi: 10.1016/j.joule.2021.06.015
  41. Anglou, E.; Ganesan, A.; Chang, Y.; Gołąbek, K.M.; Fu, Q.; Bradley, W.; Jones, C.W.; Sievers, C.; Nair, S.; Boukouvala, F. Process development and techno-economic analysis for mechanochemical recycling of poly(ethylene terephthalate). Chem. Eng. J. 2024, 481, 148278. doi: 10.1016/j.cej.2023.148278
  42. Uekert, T.; Singh, A.; DesVeaux, J.S.; Ghosh, T.; Bhatt, A.; Yadav, G.; Afzal, S.; Walzberg, J.; Knauer, K.M.; Nicholson, S.R.; et al. Technical, Economic, and Environmental Comparison of Closed-Loop Recycling Technologies for Common Plastics. ACS Sustain. Chem. Eng. 2023, 11, 965–978. doi: 10.1021/acssuschemeng.2c05497
  43. Urm, J.J.; Choi, J.H.; Kim, C.; Lee, J.M. Techno-economic analysis and process optimization of a PET chemical recycling process based on Bayesian optimization. Comput. Chem. Eng. 2023, 179, 108451. doi: 10.1016/j.compchemeng.2023.108451
  44. Zhang, M.; Yu, Y.; Yan, B.; Song, X.; Liu, Y.; Feng, Y.; Wu, W.; Chen, B.; Han, B.; Mei, Q. Full valorisation of waste PET into dimethyl terephthalate and cyclic arylboronic esters. Appl. Catal. B-Environ. Energy 2024, 352, 124055. doi: 10.1016/j.apcatb.2024.124055
  45. Mo, S.; Kou, J.; Zeng, J.; Song, K.; Zhang, Y.; He, S.; Hu, Y.; Guo, Y.; Liu, X.; Chen, X.; et al. Upcycling PET wastes into high value-added 1,4-cyclohexanedimethanol (CHDM) via tandem reactions. Chem. Eng. J. 2024, 500, 157249. doi: 10.1016/j.cej.2024.157249
  46. Chen, Q.; Yan, H.; Zhao, K.; Wang, S.; Zhang, D.; Li, Y.; Fan, R.; Li, J.; Chen, X.; Zhou, X.; et al. Catalytic oxidation upcycling of polyethylene terephthalate to commodity carboxylic acids. Nat. Commun. 2024, 15, 10732. doi: 10.1038/s41467-024-54822-w
  47. Wei, X.; Zheng, W.; Chen, X.; Qiu, J.; Sun, W.; Xi, Z.; Zhao, L. Chemical upcycling of poly(ethylene terephthalate) with binary mixed alcohols toward value-added copolyester by depolymerization and repolymerization strategy. Chem. Eng. Sci. 2024, 294, 120103. doi: 10.1016/j.ces.2024.120103
  48. Wang, K.; Guo, C.; Li, J.; Wang, K.; Cao, X.; Liang, S.; Wang, J. High value-added conversion and functional recycling of waste polyethylene terephthalate (PET) plastics: A comprehensive review. J. Environ. Chem. Eng. 2024, 12, 113539. doi: 10.1016/j.jece.2024.113539
  49. Onwucha, C.N.; Ehi-Eromosele, C.O.; Ajayi, S.O.; Schaefer, M.; Indris, S.; Ehrenberg, H. Uncatalyzed Neutral Hydrolysis of Waste PET Bottles into Pure Terephthalic Acid. Ind. Eng. Chem. Res. 2023, 62, 6378–6385. doi: 10.1021/acs.iecr.2c04117
  50. Pereira, P.; Savage, P.E.; Pester, C.W. Neutral Hydrolysis of Post-Consumer Polyethylene Terephthalate Waste in Different Phases. ACS Sustain. Chem. Eng. 2023, 11, 7203–7209. doi: 10.1021/acssuschemeng.3c00946
  51. Pereira, P.; Slear, W.; Testa, A.; Reasons, K.; Guirguis, P.; Savage, P.E.; Pester, C.W. Fast hydrolysis for chemical recycling of polyethylene terephthalate (PET). RSC Sustain. 2024, 2, 1508–1514. doi: 10.1039/D4SU00034J
  52. Liu, Y.; Wang, M.; Pan, Z. Catalytic depolymerization of polyethylene terephthalate in hot compressed water. J. Supercrit. Fluids 2012, 62, 226–231. doi: 10.1016/j.supflu.2011.11.001
  53. Wang, Y.; Zhang, Y.; Song, H.; Wang, Y.; Deng, T.; Hou, X. Zinc-catalyzed ester bond cleavage: Chemical degradation of polyethylene terephthalate. J. Cleaner Prod. 2019, 208, 1469–1475. doi: 10.1016/j.jclepro.2018.10.117
  54. Campanelli, J.R.; Cooper, D.G.; Kamal, M.R. Catalyzed hydrolysis of polyethylene terephthalate melts. J. Appl. Polym. Sci. 1994, 53, 985–991. doi: 10.1002/app.1994.070530801
  55. Yun, L.-X.; Qiao, M.; Zhang, B.; Zhang, H.-T.; Wang, J.-X. Upcycling plastic wastes into high-performance nano-MOFs by efficient neutral hydrolysis for water adsorption and photocatalysis. J. Mater. Chem. A 2024, 12, 19452–19461. doi: 10.1039/D4TA02597K
  56. Yoshioka, T.; Motoki, T.; Okuwaki, A. Kinetics of Hydrolysis of Poly(ethylene terephthalate) Powder in Sulfuric Acid by a Modified Shrinking-Core Model. Ind. Eng. Chem. Res. 2001, 40, 75–79. doi: 10.1021/ie000592u
  57. Islam, M.S.; Islam, Z.; Hasan, R.; Islam Molla Jamal, A.S. Acidic hydrolysis of recycled polyethylene terephthalate plastic for the production of its monomer terephthalic acid. Prog. Rubber Plast. Recycl. Technol. 2023, 39, 12–25. doi: 10.1177/14777606221128038
  58. Yoshioka, T.; Okayama, N.; Okuwaki, A. Kinetics of Hydrolysis of PET Powder in Nitric Acid by a Modified Shrinking-Core Model. Ind. Eng. Chem. Res. 1998, 37, 336–340. doi: 10.1021/ie970459a
  59. Yang, W.; Liu, R.; Li, C.; Song, Y.; Hu, C. Hydrolysis of waste polyethylene terephthalate catalyzed by easily recyclable terephthalic acid. Waste Manag. 2021, 135, 267–274. doi: 10.1016/j.wasman.2021.09.009
  60. Yang, W.; Wang, J.; Jiao, L.; Song, Y.; Li, C.; Hu, C. Easily recoverable and reusable p-toluenesulfonic acid for faster hydrolysis of waste polyethylene terephthalate. Green Chem. 2022, 24, 1362–1372. doi: 10.1039/D1GC04567A
  61. Hoang, C.N.; Nguyen, N.T.; Doan, T.Q.; Hoang, D. Novel efficient method of chemical upcycling of waste poly(ethylene terephthalate) bottles by acidolysis with adipic acid under microwave irradiation. Polym. Degrad. Stab. 2022, 206, 110175. doi: 10.1016/j.polymdegradstab.2022.110175
  62. Abedsoltan, H. A focused review on recycling and hydrolysis techniques of polyethylene terephthalate. Polym. Eng. Sci. 2023, 63, 2651–2674. doi: 10.1002/pen.26406
  63. Paliwal, N.R.; Mungray, A.K. Ultrasound assisted alkaline hydrolysis of poly(ethylene terephthalate) in presence of phase transfer catalyst. Polym. Degrad. Stab. 2013, 98, 2094–2101. doi: 10.1016/j.polymdegradstab.2013.06.030
  64. Barredo, A.; Asueta, A.; Amundarain, I.; Leivar, J.; Miguel-Fernández, R.; Arnaiz, S.; Epelde, E.; López-Fonseca, R.; Gutiérrez-Ortiz, J.I. Chemical recycling of monolayer PET tray waste by alkaline hydrolysis. J. Environ. Chem. Eng. 2023, 11, 109823. doi: 10.1016/j.jece.2023.109823
  65. Zhang, F.; Chen, S.; Nie, S.; Luo, J.; Lin, S.; Wang, Y.; Yang, H. Waste PET as a Reactant for Lanthanide MOF Synthesis and Application in Sensing of Picric Acid. Polymers 2019, 11, 2015. doi: 10.3390/polym11122015
  66. Zhou, L.; Wang, S.; Chen, Y.; Serre, C. Direct synthesis of robust hcp UiO-66(Zr) MOF using poly(ethylene terephthalate) waste as ligand source. Microporous Mesoporous Mater. 2019, 290, 109674. doi: 10.1016/j.micromeso.2019.109674
  67. Liu, K.; Gao, X.; Liu, C.-X.; Shi, R.; Tse, E.C.M.; Liu, F.; Chen, Y. Energy-Saving Hydrogen Production by Seawater Splitting Coupled with PET Plastic Upcycling. Adv. Energy Mater. 2024, 14, 2304065. doi: 10.1002/aenm.202304065
  68. Du, M.; Xue, R.; Yuan, W.; Cheng, Y.; Cui, Z.; Dong, W.; Qiu, B. Tandem Integration of Biological and Electrochemical Catalysis for Efficient Polyester Upcycling under Ambient Conditions. Nano Lett. 2024, 24, 9768–9775. doi: 10.1021/acs.nanolett.4c02966
  69. Zhang, X.; Wei, R.; Yan, M.; Wang, X.; Wei, X.; Wang, Y.; Wang, L.; Zhang, J.; Yin, S. One-Pot Synthesis Inorganic-Organic Hybrid PdNi Bimetallenes for PET Electrocatalytic Value-Added Transformation. Adv. Funct. Mater. 2024, 34, 2401796. doi: 10.1002/adfm.202401796
  70. Zhou, H.; Ren, Y.; Li, Z.; Xu, M.; Wang, Y.; Ge, R.; Kong, X.; Zheng, L.; Duan, H. Electrocatalytic upcycling of polyethylene terephthalate to commodity chemicals and H2 fuel. Nat. Commun. 2021, 12, 4679. doi: 10.1038/s41467-021-25048-x
  71. Lozano-Martinez, P.; Torres-Zapata, T.; Martin-Sanchez, N. Directing Depolymerization of PET with Subcritical and Supercritical Ethanol to Different Monomers through Changes in Operation Conditions. ACS Sustain. Chem. Eng. 2021, 9, 9846–9853. doi: 10.1021/acssuschemeng.1c02489
  72. Liu, S.; Wang, Z.; Li, L.; Yu, S.; Xie, C.; Liu, F. Butanol alcoholysis reaction of polyethylene terephthalate using acidic ionic liquid as catalyst. J. Appl. Polym. Sci. 2013, 130, 1840–1844. doi: 10.1002/app.39246
  73. Chen, J.; Lv, J.; Ji, Y.; Ding, J.; Yang, X.; Zou, M.; Xing, L. Alcoholysis of PET to produce dioctyl terephthalate by isooctyl alcohol with ionic liquid as cosolvent. Polym. Degrad. Stab. 2014, 107, 178–183. doi: 10.1016/j.polymdegradstab.2014.05.013
  74. Kim, B.-K.; Hwang, G.-C.; Bae, S.-Y.; Yi, S.-C.; Kumazawa, H. Depolymerization of polyethyleneterephthalate in supercritical methanol. J. Appl. Polym. Sci. 2001, 81, 2102–2108. doi: 10.1002/app.1645.abs
  75. Tang, J.; Meng, X.; Cheng, X.; Zhu, Q.; Yan, D.; Zhang, Y.; Lu, X.; Shi, C.; Liu, X. Mechanistic Insights of Cosolvent Efficient Enhancement of PET Methanol Alcohololysis. Ind. Eng. Chem. Res. 2023, 62, 4917–4927. doi: 10.1021/acs.iecr.2c04419
  76. Hofmann, M.; Sundermeier, J.; Alberti, C.; Enthaler, S. Zinc(II) acetate Catalyzed Depolymerization of Poly(ethylene terephthalate). ChemistrySelect 2020, 5, 10010–10014. doi: 10.1002/slct.202002260
  77. Tanaka, S.; Sato, J.; Nakajima, Y. Capturing ethylene glycol with dimethyl carbonate towards depolymerisation of polyethylene terephthalate at ambient temperature. Green Chem. 2021, 23, 9412–9416. doi: 10.1039/D1GC02298A
  78. Huang, Y.; Ma, Y.; Cheng, Y.; Wang, L.; Li, X. Dimethyl Terephthalate Hydrogenation to Dimethyl Cyclohexanedicarboxylates over Bimetallic Catalysts on Carbon Nanotubes. Ind. Eng. Chem. Res. 2014, 53, 4604–4613. doi: 10.1021/ie500015m
  79. Xiao, H.; Zhang, C.; Zhao, J.; Zheng, Z.; Li, Y. Selective hydrogenation of dimethyl terephthalate over a potassium-modified Ni/SiO2 catalyst. RSC Adv. 2023, 13, 16363–16368. doi: 10.1039/D3RA02223D
  80. Xiao, X.; Xin, H.; Qi, Y.; Zhao, C.; Wu, P.; Li, X. One-pot conversion of dimethyl terephthalate to 1,4-cyclohexanedimethanol. Appl. Catal. A 2022, 632, 118510. doi: 10.1016/j.apcata.2022.118510
  81. Huang, Y.; Si, Y.; Guo, X.; Qin, C.; Huang, Y.; Wang, L.; Gao, X.; Yao, S.; Cheng, Y. Valorization of Waste Polyester for 1,4-Cyclohexanedimethanol Production. ACS Catal. 2025, 4570-4578. doi: 10.1021/acscatal.4c06816
  82. Li, Y.; Wang, M.; Liu, X.; Hu, C.; Xiao, D.; Ma, D. Catalytic Transformation of PET and CO2 into High-Value Chemicals. Angew. Chem. Int. Ed. 2022, 61, e202117205. doi: 10.1002/anie.202117205
  83. Helmer, R.; Borkar, S.S.; Li, A.; Mahnaz, F.; Vito, J.; Bishop, M.; Iftakher, A.; Hasan, M.M.F.; Rangarajan, S.; Shetty, M. Tandem Methanolysis and Catalytic Transfer Hydrogenolysis of Polyethylene Terephthalate to p-Xylene Over Cu/ZnZrOx Catalysts. Angew. Chem. Int. Ed. 2025, 64, e202416384. doi: 10.1002/anie.202416384
  84. Pardal, F.; Tersac, G. Kinetics of poly(ethylene terephthalate) glycolysis by diethylene glycol. Part II: Effect of temperature, catalyst and polymer morphology. Polym. Degrad. Stab. 2007, 92, 611–616. doi: 10.1016/j.polymdegradstab.2007.01.008
  85. Javed, S.; Fisse, J.; Vogt, D. Optimization and Kinetic Evaluation for Glycolytic Depolymerization of Post-Consumer PET Waste with Sodium Methoxide. Polymers 2023, 15, 687. doi: 10.3390/polym15030687
  86. López-Fonseca, R.; Duque-Ingunza, I.; de Rivas, B.; Arnaiz, S.; Gutiérrez-Ortiz, J.I. Chemical recycling of post-consumer PET wastes by glycolysis in the presence of metal salts. Polym. Degrad. Stab. 2010, 95, 1022–1028. doi: 10.1016/j.polymdegradstab.2010.03.007
  87. Javed, S.; Vogt, D. Development of Eco-Friendly and Sustainable PET Glycolysis Using Sodium Alkoxides as Catalysts. ACS Sustain. Chem. Eng. 2023, 11, 11541–11547. doi: 10.1021/acssuschemeng.3c01872
  88. Wang, Z.; Jin, Y.; Wang, Y.; Tang, Z.; Wang, S.; Xiao, G.; Su, H. Cyanamide as a Highly Efficient Organocatalyst for the Glycolysis Recycling of PET. ACS Sustain. Chem. Eng. 2022, 10, 7965–7973. doi: 10.1021/acssuschemeng.2c01235
  89. Javed, S.; Ropel, D.; Vogt, D. Sodium ethoxide as an environmentally benign and cost-effective catalyst for chemical depolymerization of post-consumer PET waste. Green Chem. 2023, 25, 1442–1452. doi: 10.1039/D2GC04548F
  90. Wang, T.; Shen, C.; Yu, G.; Chen, X. The upcycling of polyethylene terephthalate using protic ionic liquids as catalyst. Polym. Degrad. Stab. 2022, 203, 110050. doi: 10.1016/j.polymdegradstab.2022.110050
  91. Zhang, C.; He, H.; Shen, Y.; Li, Q.; Ye, X. Green Catalytic Ionic Liquids Containing Organophosphorus for Efficient Glycolysis of Waste PET Bottle Flakes. Ind. Eng. Chem. Res. 2024, 63, 10903–10913. doi: 10.1021/acs.iecr.4c01549
  92. Liu, Y.; Yao, X.; Yao, H.; Zhou, Q.; Xin, J.; Lu, X.; Zhang, S. Degradation of poly(ethylene terephthalate) catalyzed by metal-free choline-based ionic liquids. Green Chem. 2020, 22, 3122–3131. doi: 10.1039/D0GC00327A
  93. Zhang, H.; Choi, J.I.; Choi, J.-W.; Jeong, S.-M.; Lee, P.-S.; Hong, D.-Y. A highly porous MgAl2O4 spinel-supported Mn3O4 as a reusable catalyst for glycolysis of postconsumer PET waste. J. Ind. Eng. Chem. 2022, 115, 251–262. doi: 10.1016/j.jiec.2022.08.006
  94. Sun, Q.; Zheng, Y.-Y.; Yun, L.-X.; Wu, H.; Liu, R.-K.; Du, J.-T.; Gu, Y.-H.; Shen, Z.-G.; Wang, J.-X. Fe3O4 Nanodispersions as Efficient and Recoverable Magnetic Nanocatalysts for Sustainable PET Glycolysis. ACS Sustain. Chem. Eng. 2023, 11, 7586–7595. doi: 10.1021/acssuschemeng.3c01206
  95. Anggo Krisbiantoro, P.; Chiao, Y.-W.; Liao, W.; Sun, J.-P.; Tsutsumi, D.; Yamamoto, H.; Wu, C.W. K. Catalytic glycolysis of polyethylene terephthalate (PET) by solvent-free mechanochemically synthesized MFe2O4 (M = Co, Ni, Cu and Zn) spinel. Chem. Eng. J. 2022, 450, 137926. doi: 10.1016/j.cej.2022.137926
  96. Cao, J.; Lin, Y.; Jiang, W.; Wang, W.; Li, X.; Zhou, T.; Sun, P.; Pan, B.; Li, A.; Zhang, Q. Mechanism of the Significant Acceleration of Polyethylene Terephthalate Glycolysis by Defective Ultrathin ZnO Nanosheets with Heteroatom Doping. ACS Sustain. Chem. Eng. 2022, 10, 5476–5488. doi: 10.1021/acssuschemeng.1c08656
  97. Mo, S.; Guo, Y.; Liu, X.; Wang, Y. Efficient depolymerization of PET over Ti-doped SBA-15 with abundant Lewis acid sites via glycolysis. Catal. Sci. Technol. 2023, 13, 6561–6569. doi: 10.1039/D3CY01127E
  98. Veregue, F.R.; Pereira da Silva, C.T.; Moisés, M.P.; Meneguin, J.G.; Guilherme, M.R.; Arroyo, P.A.; Favaro, S.L.; Radovanovic, E.; Girotto, E.M.; Rinaldi, A.W. Ultrasmall Cobalt Nanoparticles as a Catalyst for PET Glycolysis: A Green Protocol for Pure Hydroxyethyl Terephthalate Precipitation without Water. ACS Sustain. Chem. Eng. 2018, 6, 12017–12024. doi: 10.1021/acssuschemeng.8b02294
  99. Lechuga-Islas, V.D.; Sánchez-Cerrillo, D.M.; Stumpf, S.; Guerrero-Santos, R.; Schubert, U.S.; Guerrero-Sánchez, C. Thermo-responsive polymer catalysts for polyester recycling processes: switching from homogeneous catalysis to heterogeneous separations. Polym. Chem. 2023, 14, 1893–1904. doi: 10.1039/D2PY01520J
  100. Clark, R.A.; Shaver, M.P. Depolymerization within a Circular Plastics System. Chem. Rev. 2024, 124, 2617–2650. doi: 10.1021/acs.chemrev.3c00739
  101. Zhang, Y.; Tian, F.; Wu, Z.; Li, X.; Liu, X.; He, Y. Chemical conversion of waste PET to valued-added bis(2-hydroxyethyl) terephthalamide through aminolysis. Mater. Today Commun. 2022, 32, 104045. doi: 10.1016/j.mtcomm.2022.104045
  102. Mersha, D.A.; Gesese, T.N.; Sendekie, Z.B.; Admase, A.T.; Bezie, A.J. Operating conditions, products and sustainable recycling routes of aminolysis of polyethylene terephthalate (PET)—A review. Polym. Bull. 2024, 81, 11563–11579. doi: 10.1007/s00289-024-05259-0
  103. Demarteau, J.; Olazabal, I.; Jehanno, C.; Sardon, H. Aminolytic upcycling of poly(ethylene terephthalate) wastes using a thermally-stable organocatalyst. Polym. Chem. 2020, 11, 4875–4882. doi: 10.1039/D0PY00067A
  104. Natarajan, J.; Madras, G.; Chatterjee, K. Poly(ester amide)s from Poly(ethylene terephthalate) Waste for Enhancing Bone Regeneration and Controlled Release. ACS Appl. Mater. Interfaces 2017, 9, 28281–28297. doi: 10.1021/acsami.7b09299
  105. Padhan, R.K.; Gupta, A.A. Preparation and evaluation of waste PET derived polyurethane polymer modified bitumen through in situ polymerization reaction. Constr. Build. Mater. 2018, 158, 337–345. doi: 10.1016/j.conbuildmat.2017.09.147
  106. Chan, K.; Zinchenko, A. Conversion of waste bottles’ PET to a hydrogel adsorbent via PET aminolysis. J. Environ. Chem. Eng. 2021, 9, 106129. doi: 10.1016/j.jece.2021.106129
  107. Chan, K.; Zinchenko, A. Aminolysis-assisted hydrothermal conversion of waste PET plastic to N-doped carbon dots with markedly enhanced fluorescence. J. Environ. Chem. Eng. 2022, 10, 107749. doi: 10.1016/j.jece.2022.107749
  108. Kratish, Y.; Li, J.; Liu, S.; Gao, Y.; Marks, T.J. Polyethylene Terephthalate Deconstruction Catalyzed by a Carbon-Supported Single-Site Molybdenum-Dioxo Complex. Angew. Chem. Int. Ed. 2020, 59, 19857–19861. doi: 10.1002/anie.202007423
  109. Jing, Y.; Wang, Y.; Furukawa, S.; Xia, J.; Sun, C.; Hülsey, M.J.; Wang, H.; Guo, Y.; Liu, X.; Yan, N. Towards the Circular Economy: Converting Aromatic Plastic Waste Back to Arenes over a Ru/Nb2O5 Catalyst. Angew. Chem. Int. Ed. 2021, 60, 5527–5535. doi: 10.1002/anie.202011063
  110. Hongkailers, S.; Jing, Y.; Wang, Y.; Hinchiranan, N.; Yan, N. Recovery of Arenes from Polyethylene Terephthalate (PET) over a Co/TiO2 Catalyst. ChemSusChem 2021, 14, 4330–4339. doi: 10.1002/cssc.202100956
  111. Ye, M.; Li, Y.; Yang, Z.; Yao, C.; Sun, W.; Zhang, X.; Chen, W.; Qian, G.; Duan, X.; Cao, Y.; et al. Ruthenium/TiO2-Catalyzed Hydrogenolysis of Polyethylene Terephthalate: Reaction Pathways Dominated by Coordination Environment. Angew. Chem. Int. Ed. 2023, 62, e202301024. doi: 10.1002/anie.202301024
  112. Gao, Z.; Ma, B.; Chen, S.; Tian, J.; Zhao, C. Converting waste PET plastics into automobile fuels and antifreeze components. Nat. Commun. 2022, 13, 3343. doi: 10.1038/s41467-022-31078-w
  113. Gala, A.; Guerrero, M.; Guirao, B.; Domine, M.E.; Serra, J.M. Characterization and Distillation of Pyrolysis Liquids Coming from Polyolefins Segregated of MSW for Their Use as Automotive Diesel Fuel. Energy Fuels 2020, 34, 5969–5982. doi: 10.1021/acs.energyfuels.0c00403
  114. Zou, L.; Xu, R.; Wang, H.; Wang, Z.; Sun, Y.; Li, M. Chemical recycling of polyolefins: A closed-loop cycle of waste to olefins. Natl. Sci. Rev. 2023, 10, nwad207. doi: 10.1093/nsr/nwad207
  115. Antelava, A.; Jablonska, N.; Constantinou, A.; Manos, G.; Salaudeen, S.A.; Dutta, A.; Al-Salem, S.M. Energy Potential of Plastic Waste Valorization: A Short Comparative Assessment of Pyrolysis versus Gasification. Energy Fuels 2021, 35, 3558–3571. doi: 10.1021/acs.energyfuels.0c04017
  116. Wall, L.A.; Straus, S. Pyrolysis of polyolefins. J. Polym Sci. 1960, 44, 313–323. doi: 10.1002/pol.1960.1204414404
  117. Zhang, Y.; Fu, Z.; Wang, W.; Ji, G.; Zhao, M.; Li, A. Kinetics, Product Evolution, and Mechanism for the Pyrolysis of Typical Plastic Waste. ACS Sustain. Chem. Eng. 2022, 10, 91–103. doi: 10.1021/acssuschemeng.1c04915
  118. Selvam, E.; Yu, K.; Ngu, J.; Najmi, S.; Vlachos, D.G. Recycling polyolefin plastic waste at short contact times via rapid joule heating. Nat. Commun. 2024, 15, 5662. doi: 10.1038/s41467-024-50035-3
  119. Vollmer, I.; Jenks, M.J.F.; Mayorga González, R.; Meirer, F.; Weckhuysen, B.M. Plastic Waste Conversion over a Refinery Waste Catalyst. Angew. Chem. Int. Ed. 2021, 60, 16101–16108. doi: 10.1002/anie.202104110
  120. Dong, Z.; Chen, W.; Xu, K.; Liu, Y.; Wu, J.; Zhang, F. Understanding the Structure—Activity Relationships in Catalytic Conversion of Polyolefin Plastics by Zeolite-Based Catalysts: A Critical Review. ACS Catal. 2022, 12, 14882–14901. doi: 10.1021/acscatal.2c04915
  121. Akhtar, M.N.; Riaz, S.; Ahmad, N.; Jaseer, E.A. Pioneering Aromatic Generation from Plastic Waste via Catalytic Thermolysis: A Minireview. Energy Fuels 2024, 38, 11363–11390. doi: 10.1021/acs.energyfuels.4c00691
  122. Chen, W.; Lu, J.; Zhang, C.; Xie, Y.; Wang, Y.; Wang, J.; Zhang, R. Aromatic hydrocarbons production and synergistic effect of plastics and biomass via one-pot catalytic co-hydropyrolysis on HZSM-5. J. Anal. Appl. Pyrolysis 2020, 147, 104800. doi: 10.1016/j.jaap.2020.104800
  123. Xue, Y.; Johnston, P.; Bai, X. Effect of catalyst contact mode and gas atmosphere during catalytic pyrolysis of waste plastics. Energy Convers. Manag. 2017, 142, 441–451. doi: 10.1016/j.enconman.2017.03.071
  124. Finelli, V.; Gentilin, V.; Mossotti, G.; Ricchiardi, G.; Piovano, A.; Crocellà, V.; Groppo, E. The role of porosity and acidity in the catalytic upcycling of polyethylene. Catal. Today 2023, 419, 114142. doi: 10.1016/j.cattod.2023.114142
  125. Duan, J.; Chen, W.; Wang, C.; Wang, L.; Liu, Z.; Yi, X.; Fang, W.; Wang, H.; Wei, H.; Xu, S.; et al. Coking-Resistant Polyethylene Upcycling Modulated by Zeolite Micropore Diffusion. J. Am. Chem. Soc. 2022, 144, 14269–14277. doi: 10.1021/jacs.2c05125
  126. Feng, J.; Duan, J.; Hung, C.-T.; Zhang, Z.; Li, K.; Ai, Y.; Yang, C.; Zhao, Y.; Yu, Z.; Zhang, Y.; et al. Micelles Cascade Assembly to Tandem Porous Catalyst for Waste Plastics Upcycling. Angew. Chem. Int. Ed. 2024, 63, e202405252. doi: 10.1002/anie.202405252
  127. Kokuryo, S.; Miyake, K.; Uchida, Y.; Tanaka, S.; Miyamoto, M.; Oumi, Y.; Mizusawa, A.; Kubo, T.; Nishiyama, N. Design of Zr- and Al-Doped *BEA-Type Zeolite to Boost LDPE Cracking. ACS Omega 2022, 7, 12971–12977. doi: 10.1021/acsomega.2c00283
  128. Zhou, S.; Li, P.; Pan, H.; Zhang, Y. Improvement of Aromatics Selectivity from Catalytic Pyrolysis of Low-Density Polyethylene with Metal-Modified HZSM-5 in a CO2 Atmosphere. Ind. Eng. Chem. Res. 2022, 61, 11407–11416. doi: 10.1021/acs.iecr.2c01287
  129. Fu, L.; Xiong, Q.; Wang, Q.; Cai, L.; Chen, Z.; Zhou, Y. Catalytic Pyrolysis of Waste Polyethylene Using Combined CaO and Ga/ZSM-5 Catalysts for High Value-Added Aromatics Production. ACS Sustain. Chem. Eng. 2022, 10, 9612–9623. doi: 10.1021/acssuschemeng.2c02881
  130. Qian, K.; Tian, W.; Yin, L.; Yang, Z.; Tian, F.; Chen, D. Aromatic production from high-density polyethylene over zinc promoted HZSM-5. Appl. Catal. B-Environ. 2023, 339, 123159. doi: 10.1016/j.apcatb.2023.123159
  131. Wang, W.; Yao, C.; Ge, X.; Pu, X.; Yuan, J.; Sun, W.; Chen, W.; Feng, X.; Qian, G.; Duan, X.; et al. Catalytic conversion of polyethylene into aromatics with Pt/ZSM-5: insights into reaction pathways and rate-controlling step regulation. J. Mater. Chem. A 2023, 11, 14933–14940. doi: 10.1039/D3TA01917A
  132. Yuan, H.; Li, C.; Shan, R.; Zhang, J.; Wu, Y.; Chen, Y. Recent developments on the zeolites catalyzed polyolefin plastics pyrolysis. Fuel Process. Technol. 2022, 238, 107531. doi: 10.1016/j.fuproc.2022.107531
  133. Kots, P.A.; Vance, B.C.; Vlachos, D.G. Polyolefin plastic waste hydroconversion to fuels, lubricants, and waxes: A comparative study. React. Chem. Eng. 2022, 7, 41–54. doi: 10.1039/D1RE00447F
  134. Sun, J.; Dong, J.; Gao, L.; Zhao, Y.-Q.; Moon, H.; Scott, S.L. Catalytic Upcycling of Polyolefins. Chem. Rev. 2024, 124, 9457–9579. doi: 10.1021/acs.chemrev.3c00943
  135. Lee, W.-T.; Bobbink, F.D.; van Muyden, A.P.; Lin, K.-H.; Corminboeuf, C.; Zamani, R.R.; Dyson, P.J. Catalytic hydrocracking of synthetic polymers into grid-compatible gas streams. Cell Rep. Phys. Sci. 2021, 2, 100332. doi: 10.1016/j.xcrp.2021.100332
  136. Liu, S.; Kots, P.A.; Vance, B.C.; Danielson, A.; Vlachos, D.G. Plastic waste to fuels by hydrocracking at mild conditions. Sci. Adv. 2021, 7, eabf8283. doi: 10.1126/sciadv.abf8283
  137. Vance, B.C.; Yuliu, Z.; Najmi, S.; Selvam, E.; Granite, J.E.; Yu, K.; Ierapetritou, M.G.; Vlachos, D.G. Unlocking naphtha from polyolefins using Ni-based hydrocracking catalysts. Chem. Eng. J. 2024, 487, 150468. doi: 10.1016/j.cej.2024.150468
  138. Rorrer, J.E.; Ebrahim, A.M.; Questell-Santiago, Y.; Zhu, J.; Troyano-Valls, C.; Asundi, A.S.; Brenner, A.E.; Bare, S.R.; Tassone, C.J.; Beckham, G.T.; et al. Role of Bifunctional Ru/Acid Catalysts in the Selective Hydrocracking of Polyethylene and Polypropylene Waste to Liquid Hydrocarbons. ACS Catal. 2022, 12, 13969–13979. doi: 10.1021/acscatal.2c03596
  139. Li, L.; Luo, H.; Shao, Z.; Zhou, H.; Lu, J.; Chen, J.; Huang, C.; Zhang, S.; Liu, X.; Xia, L.; et al. Converting Plastic Wastes to Naphtha for Closing the Plastic Loop. J. Am. Chem. Soc. 2023, 145, 1847–1854. doi: 10.1021/jacs.2c11407
  140. Vance, B.C.; Kots, P.A.; Wang, C.; Hinton, Z.R.; Quinn, C.M.; Epps, T.H.; Korley, L.T.J.; Vlachos, D.G. Single pot catalyst strategy to branched products via adhesive isomerization and hydrocracking of polyethylene over platinum tungstated zirconia. Appl. Catal. B-Environ. 2021, 299, 120483. doi: 10.1016/j.apcatb.2021.120483
  141. Wang, C.; Xie, T.; Kots, P.A.; Vance, B.C.; Yu, K.; Kumar, P.; Fu, J.; Liu, S.; Tsilomelekis, G.; Stach, E.A.; et al. Polyethylene Hydrogenolysis at Mild Conditions over Ruthenium on Tungstated Zirconia. JACS Au 2021, 1, 1422–1434. doi: 10.1021/jacsau.1c00200
  142. Chu, M.; Liu, Y.; Lou, X.; Zhang, Q.; Chen, J. Rational Design of Chemical Catalysis for Plastic Recycling. ACS Catal. 2022, 12, 4659–4679. doi: 10.1021/acscatal.2c01286
  143. Nakaji, Y.; Tamura, M.; Miyaoka, S.; Kumagai, S.; Tanji, M.; Nakagawa, Y.; Yoshioka, T.; Tomishige, K. Low-temperature catalytic upgrading of waste polyolefinic plastics into liquid fuels and waxes. Appl. Catal. B-Environ. 2021, 285, 119805. doi: 10.1016/j.apcatb.2020.119805
  144. Rorrer, J.E.; Beckham, G.T.; Román-Leshkov, Y. Conversion of Polyolefin Waste to Liquid Alkanes with Ru-Based Catalysts under Mild Conditions. JACS Au 2021, 1, 8–12. doi: 10.1021/jacsau.0c00041
  145. Rorrer, J.E.; Troyano-Valls, C.; Beckham, G.T.; Román-Leshkov, Y. Hydrogenolysis of Polypropylene and Mixed Polyolefin Plastic Waste over Ru/C to Produce Liquid Alkanes. ACS Sustain. Chem. Eng. 2021, 9, 11661–11666. doi: 10.1021/acssuschemeng.1c03786
  146. Chen, L.; Zhu, Y.; Meyer, L.C.; Hale, L.V.; Le, T.T.; Karkamkar, A.; Lercher, J.A.; Gutiérrez, O.Y.; Szanyi, J. Effect of reaction conditions on the hydrogenolysis of polypropylene and polyethylene into gas and liquid alkanes. React. Chem. Eng. 2022, 7, 844–854. doi: 10.1039/D1RE00431J
  147. Ji, H.; Wang, X.; Wei, X.; Peng, Y.; Zhang, S.; Song, S.; Zhang, H. Boosting Polyethylene Hydrogenolysis Performance of Ru-CeO2 Catalysts by Finely Regulating the Ru Sizes. Small 2023, 19, 2300903. doi: 10.1002/smll.202300903
  148. Wang, C.; Yu, K.; Sheludko, B.; Xie, T.; Kots, P.A.; Vance, B.C.; Kumar, P.; Stach, E.A.; Zheng, W.; Vlachos, D.G. A general strategy and a consolidated mechanism for low-methane hydrogenolysis of polyethylene over ruthenium. Appl. Catal. B-Environ. 2022, 319, 121899. doi: 10.1016/j.apcatb.2022.121899
  149. Tennakoon, A.; Wu, X.; Paterson, A.L.; Patnaik, S.; Pei, Y.; LaPointe, A.M.; Ammal, S.C.; Hackler, R.A.; Heyden, A.; Slowing, I.I.; et al. Catalytic upcycling of high-density polyethylene via a processive mechanism. Nat. Catal. 2020, 3, 893–901. doi: 10.1038/s41929-020-00519-4
  150. Tennakoon, A.; Wu, X.; Meirow, M.; Howell, D.; Willmon, J.; Yu, J.; Lamb, J.V.; Delferro, M.; Luijten, E.; Huang, W.; et al. Two Mesoporous Domains Are Better Than One for Catalytic Deconstruction of Polyolefins. J. Am. Chem. Soc. 2023, 145, 17936–17944. doi: 10.1021/jacs.3c05447
  151. Basset, J.M.; Copéret, C.; Lefort, L.; Maunders, B.M.; Maury, O.; Le Roux, E.; Saggio, G.; Soignier, S.; Soulivong, D.; Sunley, G.J.; et al. Primary Products and Mechanistic Considerations in Alkane Metathesis. J. Am. Chem. Soc. 2005, 127, 8604–8605. doi: 10.1021/ja051679f
  152. Jia, X.; Qin, C.; Friedberger, T.; Guan, Z.; Huang, Z. Efficient and selective degradation of polyethylenes into liquid fuels and waxes under mild conditions. Sci. Adv. 2016, 2, e1501591. doi: 10.1126/sciadv.1501591
  153. Ellis, L.D.; Orski, S.V.; Kenlaw, G.A.; Norman, A.G.; Beers, K.L.; Román-Leshkov, Y.; Beckham, G.T. Tandem Heterogeneous Catalysis for Polyethylene Depolymerization via an Olefin-Intermediate Process. ACS Sustain. Chem. Eng. 2021, 9, 623–628. doi: 10.1021/acssuschemeng.0c07612
  154. Kim, D.; Hinton, Z.R.; Bai, P.; Korley, L.T.J.; Epps, T.H.; Lobo, R.F. Metathesis, molecular redistribution of alkanes, and the chemical upgrading of low-density polyethylene. Appl. Catal. B-Environ. 2022, 318, 121873. doi: 10.1016/j.apcatb.2022.121873
  155. Conk, R.J.; Hanna, S.; Shi, J.X.; Yang, J.; Ciccia, N.R.; Qi, L.; Bloomer, B.J.; Heuvel, S.; Wills, T.; Su, J.; et al. Catalytic deconstruction of waste polyethylene with ethylene to form propylene. Science 2022, 377, 1561–1566. doi: 10.1126/science.add1088
  156. Wang, N.M.; Strong, G.; DaSilva, V.; Gao, L.; Huacuja, R.; Konstantinov, I.A.; Rosen, M.S.; Nett, A.J.; Ewart, S.; Geyer, R.; et al. Chemical Recycling of Polyethylene by Tandem Catalytic Conversion to Propylene. J. Am. Chem. Soc. 2022, 144, 18526–18531. doi: 10.1021/jacs.2c07781
  157. Cui, Y.; Zhang, Y.; Cui, L.; Liu, Y.; Li, B.; Liu, W. Microwave-assisted pyrolysis of polypropylene plastic for liquid oil production. J. Cleaner Prod. 2023, 411, 137303. doi: 10.1016/j.jclepro.2023.137303
  158. Wang, S.; Hu, Y.; Lu, S.; Zhang, B.; Li, S.; Chen, X. Highly Efficient Recycling Waste Plastic into Hydrogen and Carbon Nanotubes through a Double Layer Microwave-Assisted Pyrolysis Method. Macromol. Rapid Commun. 2024, 45, 2400270. doi: 10.1002/marc.202400270
  159. Jie, X.; Li, W.; Slocombe, D.; Gao, Y.; Banerjee, I.; Gonzalez-Cortes, S.; Yao, B.; AlMegren, H.; Alshihri, S.; Dilworth, J.; et al. Microwave-initiated catalytic deconstruction of plastic waste into hydrogen and high-value carbons. Nat. Catal. 2020, 3, 902–912. doi: 10.1038/s41929-020-00518-5
  160. Kanbur, U.; Zang, G.; Paterson, A.L.; Chatterjee, P.; Hackler, R.A.; Delferro, M.; Slowing, I.I.; Perras, F.A.; Sun, P.; Sadow, A.D. Catalytic carbon-carbon bond cleavage and carbon-element bond formation give new life for polyolefins as biodegradable surfactants. Chem 2021, 7, 1347–1362. doi: 10.1016/j.chempr.2021.03.007
  161. Wang, K.; Jia, R.; Cheng, P.; Shi, L.; Wang, X.; Huang, L. Highly Selective Catalytic Oxi-upcycling of Polyethylene to Aliphatic Dicarboxylic Acid under a Mild Hydrogen-Free Process. Angew. Chem. Int. Ed. 2023, 62, e202301340. doi: 10.1002/anie.202301340
  162. Jiao, X.; Zheng, K.; Chen, Q.; Li, X.; Li, Y.; Shao, W.; Xu, J.; Zhu, J.; Pan, Y.; Sun, Y.; et al. Photocatalytic Conversion of Waste Plastics into C2 Fuels under Simulated Natural Environment Conditions. Angew. Chem. Int. Ed. 2020, 59, 15497–15501. doi: 10.1002/anie.201915766
  163. Zhao, B.; Hu, Z.; Sun, Y.; Hajiayi, R.; Wang, T.; Jiao, N. Selective Upcycling of Polyolefins into High-Value Nitrogenated Chemicals. J. Am. Chem. Soc. 2024, 146, 28605–28611. doi: 10.1021/jacs.4c07965
  164. Zayoud, A.; Dao Thi, H.; Kusenberg, M.; Eschenbacher, A.; Kresovic, U.; Alderweireldt, N.; Djokic, M.; Van Geem, K.M. Pyrolysis of end-of-life polystyrene in a pilot-scale reactor: Maximizing styrene production. Waste Manag. 2022, 139, 85–95. doi: 10.1016/j.wasman.2021.12.018
  165. Ojha, D.K.; Vinu, R. Resource recovery via catalytic fast pyrolysis of polystyrene using zeolites. J. Anal. Appl. Pyrolysis 2015, 113, 349–359. doi: 10.1016/j.jaap.2015.02.024
  166. Amjad, U.-E.-S.; Ishaq, M.; Rehman, H.U.; Ahmad, N.; Sherin, L.; Hussain, M.; Mustafa, M. Diesel and gasoline like fuel production with minimum styrene content from catalytic pyrolysis of polystyrene. Environ. Prog. Sustain. Energy 2021, 40, e13493. doi: 10.1002/ep.13493
  167. Audisio, G.; Bertini, F.; Beltrame, P.L.; Carniti, P. Catalytic degradation of polymers: Part III—Degradation of polystyrene. Polym. Degrad. Stab. 1990, 29, 191–200. doi: 10.1016/0141-3910(90)90030-B
  168. Marczewski, M.; Kamińska, E.; Marczewska, H.; Godek, M.; Rokicki, G.; Sokołowski, J. Catalytic decomposition of polystyrene. The role of acid and basic active centers. Appl. Catal. B-Environ. 2013, 129, 236–246. doi: 10.1016/j.apcatb.2012.09.027
  169. Nikitas, N.F.; Skolia, E.; Gkizis, P.L.; Triandafillidi, I.; Kokotos, C.G. Photochemical aerobic upcycling of polystyrene plastics to commodity chemicals using anthraquinone as the photocatalyst. Green Chem. 2023, 25, 4750–4759. doi: 10.1039/D3GC00986F
  170. Oh, S.; Stache, E.E. Chemical Upcycling of Commercial Polystyrene via Catalyst-Controlled Photooxidation. J. Am. Chem. Soc. 2022, 144, 5745–5749. doi: 10.1021/jacs.2c01411
  171. Li, T.; Vijeta, A.; Casadevall, C.; Gentleman, A.S.; Euser, T.; Reisner, E. Bridging Plastic Recycling and Organic Catalysis: Photocatalytic Deconstruction of Polystyrene via a C-H Oxidation Pathway. ACS Catal. 2022, 12, 8155–8163. doi: 10.1021/acscatal.2c02292
  172. Qin, C.; Shen, T.; Tang, C.; Jiao, N. FeCl2-Promoted Cleavage of the Unactivated C-C Bond of Alkylarenes and Polystyrene: Direct Synthesis of Arylamines. Angew. Chem. Int. Ed. 2012, 51, 6971–6975. doi: 10.1002/anie.201202464
  173. Qin, Y.; Zhang, T.; Ching, H.Y.V.; Raman, G.S.; Das, S. Integrated strategy for the synthesis of aromatic building blocks via upcycling of real-life plastic wastes. Chem 2022, 8, 2472–2484. doi: 10.1016/j.chempr.2022.06.002
  174. Ong, A.; Teo, J.Y.Q.; Feng, Z.; Tan, T.T.Y.; Lim, J.Y.C. Organocatalytic Aerobic Oxidative Degradation of Polystyrene to Aromatic Acids. ACS Sustain. Chem. Eng. 2023, 11, 12514–12522. doi: 10.1021/acssuschemeng.3c01387
  175. Oh, S.; Stache, E.E. Mechanistic Insights Enable Divergent Product Selectivity in Catalyst-Controlled Photooxidative Degradation of Polystyrene. ACS Catal. 2023, 13, 10968–10975. doi: 10.1021/acscatal.3c02516
  176. Xu, Z.; Sun, D.; Xu, J.; Yang, R.; Russell, J.D.; Liu, G. Progress and Challenges in Polystyrene Recycling and Upcycling. ChemSusChem 2024, 17, e202400474. doi: 10.1002/cssc.202400474
  177. Xu, Z.; Pan, F.; Sun, M.; Xu, J.; Munyaneza, N.E.; Croft, Z.L.; Cai, G.; Liu, G. Cascade degradation and upcycling of polystyrene waste to high-value chemicals. Proc. Natl. Acad. Sci. USA 2022, 119, e2203346119. doi: 10.1073/pnas.2203346119
  178. Zhang, M.; Buekens, A.; Jiang, X.; Li, X. Dioxins and polyvinylchloride in combustion and fires. Waste Manag. Res. 2015, 33, 630–643. doi: 10.1177/0734242X15590651
  179. Yuan, J.; Wang, W.; Sun, W.; Yang, Z.; Cao, Y.; Chen, W.; Ge, X.; Qian, G.; Feng, X.; Duan, X.; et al. Poisoning effect of polyvinyl chloride on the catalytic pyrolysis of mixed plastics over zeolites. Sci. China Chem. 2024, 67, 2265–2273. doi: 10.1007/s11426-024-2111-5
  180. Meng, H.; Liu, J.; Xia, Y.; Hu, B.; Sun, H.; Li, J.; Lu, Q. Migration and transformation mechanism of Cl during polyvinyl chloride pyrolysis: The role of structural defects. Polym. Degrad. Stab. 2024, 224, 110750. doi: 10.1016/j.polymdegradstab.2024.110750
  181. Wu, J.; Papanikolaou, K.G.; Cheng, F.; Addison, B.; Cuthbertson, A.A.; Mavrikakis, M.; Huber, G.W. Kinetic Study of Polyvinyl Chloride Pyrolysis with Characterization of Dehydrochlorinated PVC. ACS Sustain. Chem. Eng. 2024, 12, 7402–7413. doi: 10.1021/acssuschemeng.4c00564
  182. Gui, B.; Qiao, Y.; Wan, D.; Liu, S.; Han, Z.; Yao, H.; Xu, M. Nascent tar formation during polyvinylchloride (PVC) pyrolysis. Proc. Combust. Inst. 2013, 34, 2321–2329. doi: 10.1016/j.proci.2012.08.013
  183. Čolnik, M.; Kotnik, P.; Knez, Ž.; Škerget, M. Degradation of Polyvinyl Chloride (PVC) Waste with Supercritical Water. Processes 2022, 10, 1940. doi: 10.3390/pr10101940
  184. Svadlenak, S.; Wojcik, S.; Ogunlalu, O.; Vu, M.; Dor, M.; Boudouris, B.W.; Wildenschild, D.; Goulas, K.A. Upcycling of polyvinyl chloride to hydrocarbon waxes via dechlorination and catalytic hydrogenation. Appl. Catal. B-Environ. 2023, 338, 123065. doi: 10.1016/j.apcatb.2023.123065
  185. Yang, W.-T.; Xie, Y.-Y.; Xu, S.-M.; Wu, G.; Wang, Y.-Z. Upcycling of polyvinyl chloride to porous carbon for high-performance electromagnetic wave absorption materials. Chem. Eng. J. 2024, 496, 154054. doi: 10.1016/j.cej.2024.154054
  186. Nshizirungu, T.; Agarwal, A.; Jo, Y.T.; Rana, M.; Shin, D.; Park, J.-H. Chlorinated polyvinyl chloride (CPVC) assisted leaching of lithium and cobalt from spent lithium-ion battery in subcritical water. J. Hazard. Mater. 2020, 393, 122367. doi: 10.1016/j.jhazmat.2020.122367
  187. Fagnani, D.E.; Kim, D.; Camarero, S.I.; Alfaro, J.F.; McNeil, A.J. Using waste poly(vinyl chloride) to synthesize chloroarenes by plasticizer-mediated electro(de)chlorination. Nat. Chem. 2023, 15, 222–229. doi: 10.1038/s41557-022-01078-w
  188. Feng, B.; Jing, Y.; Liu, X.; Guo, Y.; Wang, Y. Waste PVC upcycling: Transferring unmanageable Cl species into value-added Cl-containing chemicals. Appl. Catal. B-Environ. 2023, 331, 122671. doi: 10.1016/j.apcatb.2023.122671
  189. Jha, R.K.; Neyhouse, B.J.; Young, M.S.; Fagnani, D.E.; McNeil, A.J. Revisiting poly(vinyl chloride) reactivity in the context of chemical recycling. Chem. Sci. 2024, 15, 5802–5813. doi: 10.1039/D3SC06758K
  190. Kameda, T.; Ono, M.; Grause, G.; Mizoguchi, T.; Yoshioka, T. Chemical modification and dechlorination of polyvinyl chloride by substitution with thiocyanate as a nucleophile. Polym. Eng. Sci. 2010, 50, 69–75. doi: 10.1002/pen.21512
  191. Deliballi, Z.; Demir-Cakan, R.; Kiskan, B.; Yagci, Y. Self-Healable and Recyclable Sulfur Rich Poly(vinyl chloride) by S-S Dynamic Bonding. Macromol. Chem. Phys. 2023, 224, 2100423. doi: 10.1002/macp.202100423
  192. Lieberzeit, P.; Bekchanov, D.; Mukhamediev, M. Polyvinyl chloride modifications, properties, and applications: Review. Polym. Adv. Technol. 2022, 33, 1809–1820. doi: 10.1002/pat.5656
  193. Jabrail, F.H.; Awad, H.M.; Matlob, A.A. Dechlorination of landfill poly(vinyl chloride) waste and estimation of recovered chlorine. Polym. Polym. Compos. 2021, 29, 1273–1281. doi: 10.1177/09673911211037508
  194. Glas, D.; Hulsbosch, J.; Dubois, P.; Binnemans, K.; De Vos, D.E. End-of-Life Treatment of Poly(Vinyl Chloride) and Chlorinated Polyethylene by Dehydrochlorination in Ionic Liquids. ChemSusChem 2014, 7, 610–617. doi: 10.1002/cssc.201300970
  195. Oster, K.; Tedstone, A.; Greer, A.J.; Budgen, N.; Garforth, A.; Hardacre, C. Dehydrochlorination of PVC in multi-layered blisterpacks using ionic liquids. Green Chem. 2020, 22, 5132–5142. doi: 10.1039/D0GC01312A
  196. Park, E.J.; Park, B.C.; Kim, Y.J.; Canlier, A.; Hwang, T.S. Elimination and Substitution Compete During Amination of Poly(vinyl chloride) with Ehtylenediamine: XPS Analysis and Approach of Active Site Index. Macromol. Res. 2018, 26, 913–923. doi: 10.1007/s13233-018-6123-z
  197. Kameda, T.; Fukuda, Y.; Grause, G.; Yoshioka, T. Effect of the nucleophilicity and solvent on the chemical modification of flexible poly(vinyl chloride) by substitution. Polym. Eng. Sci. 2011, 51, 1108–1115. doi: 10.1002/pen.21693
  198. Ling, M.; Ma, D.; Hu, X.; Liu, Z.; Wang, D.; Feng, Q. Hydrothermal treatment of polyvinyl chloride: Reactors, dechlorination chemistry, application, and challenges. Chemosphere 2023, 316, 137718. doi: 10.1016/j.chemosphere.2022.137718
  199. Xiu, F.-R.; Yu, X.; Qi, Y. A high-efficiency and low-temperature subcritical water dechlorination strategy of polyvinyl chloride using coal fly ash (CFA) and coal gangue (CG) as enhancers. J. Cleaner Prod. 2020, 260, 121085. doi: 10.1016/j.jclepro.2020.121085
  200. Xiu, F.-R.; Yang, R.; Qi, Y.; Zhou, K.; Wang, J.; Shao, W.; Zhou, H.; Zhan, L. High-efficiency promotion on dechlorination of polyvinyl chloride in subcritical water treatment by introducing waste concrete. Process Saf. Environ. Protect. 2023, 174, 1056–1064. doi: 10.1016/j.psep.2023.05.020
  201. Song, J.; Wang, J.; Sima, J.; Zhu, Y.; Du, X.; Williams, P.T.; Huang, Q. Dechlorination of waste polyvinyl chloride (PVC) through non-thermal plasma. Chemosphere 2023, 338, 139535. doi: 10.1016/j.chemosphere.2023.139535
  202. Zhang, Z.; Wang, J.; Ge, X.; Wang, S.; Li, A.; Li, R.; Shen, J.; Liang, X.; Gan, T.; Han, X.; et al. Mixed Plastics Wastes Upcycling with High-Stability Single-Atom Ru Catalyst. J. Am. Chem. Soc. 2023, 145, 22836–22844. doi: 10.1021/jacs.3c09338
  203. Zheng, K.; Wu, Y.; Hu, Z.; Wang, S.; Jiao, X.; Zhu, J.; Sun, Y.; Xie, Y. Progress and perspective for conversion of plastic wastes into valuable chemicals. Chem. Soc. Rev. 2023, 52, 8–29. doi: 10.1039/D2CS00688J
  204. Li, M.; Zhang, S. Tandem Chemical Depolymerization and Photoreforming of Waste PET Plastic to High-Value-Added Chemicals. ACS Catal. 2024, 14, 2949–2958. doi: 10.1021/acscatal.3c05535
  205. Jerdy, A.C.; Pham, T.; González-Borja, M.Á.; Atallah, P.; Soules, D.; Abbott, R.; Lobban, L.; Crossley, S. Impact of the presence of common polymer additives in thermal and catalytic polyethylene decomposition. Appl. Catal. B-Environ. 2023, 325, 122348. doi: 10.1016/j.apcatb.2022.122348
  206. Qiu, Z.; Lin, S.; Chen, Z.; Chen, A.; Zhou, Y.; Cao, X.; Wang, Y.; Lin, B.-L. A reusable, impurity-tolerant and noble metal–free catalyst for hydrocracking of waste polyolefins. Sci. Adv. 2023, 9, eadg5332. doi: 10.1126/sciadv.adg5332
  207. Hubáček, J.; Lederer, J.; Kuráň, P.; Koutník, P.; Gholami, Z.; Zbuzek, M.; Bačiak, M. Dechlorination during pyrolysis of plastics: The potential of stepwise pyrolysis in combination with metal sorbents. Fuel Process. Technol. 2022, 231, 107226. doi: 10.1016/j.fuproc.2022.107226
  208. Oasmaa, A.; Qureshi, M.S.; Pihkola, H.; Ruohomäki, I.; Raitila, J.; Lindfors, C.; Mannila, J.; Zu Castell-Rudenhausen, M.; Deviatkin, I.; Korpijärvi, K. Fast Pyrolysis of Industrial Waste Residues to Liquid Intermediates—Experimental and Conceptual Study; VTT Technical Research Centre of Finland: Espoo, Finland, 2019; Volume 44, p. VTT-R-512-19.