Pyrolytic Depolymerization of Polyolefins Catalysed by Zirconium‐based UiO‐66 Metal–Organic Frameworks

Pyrolytic Depolymerization of Polyolefins Catalysed by Zirconium‐based UiO‐66 Metal–Organic Frameworks

Angewandte Chemie International Edition

10.1002/anie.202408718

https://doi.org/10.1002/anie.202408718

Jerry Zhi Xiong Heng, Tristan Tsai Yuan Tan, Xin Li, Wei Wei Loh, Yuting Chen, Zhenxiang Xing, Zhiyan Lim, Jennet Li Ying Ong, Katherine Shiyun Lin, Yusuke Nishiyama, Takefumi Yoshida, Lili Zhang, Ken‐ichi Otake, Susumu Kitagawa, Xian Jun Loh, Enyi Ye, Jason Y. C. Lim

Heterogeneous catalysis, valorisation, polyethylene, polypropylene, hydrocarbons

01 August 2024

Heng, J. Z. X., Tan, T. T. Y., Li, X., Loh, W. W., Chen, Y., Xing, Z., Lim, Z., Ong, J. L. Y., Lin, K. S., Nishiyama, Y., Yoshida, T., Zhang, L., Otake, K., Kitagawa, S., Loh, X. J., Ye, E., & Lim, J. Y. C. (2024). Pyrolytic Depolymerization of Polyolefins Catalysed by Zirconium‐based UiO‐66 Metal–Organic Frameworks. Angewandte Chemie International Edition, 63(44). Portico. https://doi.org/10.1002/anie.202408718

Polyolefins such as polyethylenes and polypropylenes are the most‐produced plastic waste globally, yet are difficult to convert into useful products due to their unreactivity. Pyrolysis is a practical method for large‐scale treatment of mixed, contaminated plastic, allowing for their conversion into industrially‐relevant petrochemicals. Metal–organic frameworks (MOFs), despite their tremendous utility in heterogeneous catalysis, have been overlooked for polyolefin depolymerization due to their perceived thermal instabilities and inability of polyethylenes and polypropylenes to penetrate their pores. Herein, we demonstrate the viability of UiO‐66 MOFs containing coordinatively‐unsaturated zirconium nodes, as effective catalysts for pyrolysis that significantly enhances the yields of valuable liquid and gas hydrocarbons, whilst halving the amounts of residual solids produced. Reactions occur on the Lewis‐acidic UiO‐66 nodes, without the need for noble metals, and yield aliphatic product distributions distinctly different from the aromatic‐rich hydrocarbons that can be obtained from zeolite catalysis. We also demonstrate the first unambiguous characterization of polyolefin penetration into UiO‐66 pores at pyrolytic temperatures, allowing access to the abundant Zr‐oxo nodes within the MOF interior for efficient C−C cleavage. Our work highlights the potential of MOFs as highly‐designable heterogeneous catalysts for depolymerisation of plastics, which can complement conventional catalysts in reactivity.

Publisher Copyright

This research / project is supported by the Agency for Science, Technology and Research - UGTO Seed Fund
Grant Reference no. : C211718005

This research / project is supported by the National Research Foundation, Singapore (NRF) - National Research Foundation Fellowship
Grant Reference no. : NRF-NRFF15-2023-0007

This research / project is supported by the Kyoto University - On-site Laboratory Program
Grant Reference no. : NA

This research / project is supported by the KAKENHI - Grant-in-Aid for Scientific Research (S)
Grant Reference no. : JP22H05005

This is the peer reviewed version of the following article: Heng, J. Z. X., Tan, T. T. Y., Li, X., Loh, W. W., Chen, Y., Xing, Z., Lim, Z., Ong, J. L. Y., Lin, K. S., Nishiyama, Y., Yoshida, T., Zhang, L., Otake, K., Kitagawa, S., Loh, X. J., Ye, E., & Lim, J. Y. C. (2024). Pyrolytic Depolymerization of Polyolefins Catalysed by Zirconium‐based UiO‐66 Metal–Organic Frameworks. Angewandte Chemie International Edition, 63(44). Portico. https://doi.org/10.1002/anie.202408718, which has been published in final form at https://doi.org/10.1002/anie.202408718. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.

https://oar.a-star.edu.sg/communities-collections/articles/21667

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